WorldWideScience

Sample records for satellite infrared spectrometer

  1. TIRCIS: thermal infrared compact imaging spectrometer for small satellite applications

    Science.gov (United States)

    Wright, Robert; Lucey, Paul; Crites, Sarah; Garbeil, Harold; Wood, Mark; Pilger, Eric; Gabrieli, Andrea; Honniball, Casey

    2016-10-01

    Measurements of reflectance or emittance in tens of narrow, contiguous wavebands, allow for the derivation of laboratory quality spectra remotely, from which the chemical composition and physical properties of targets can be determined. Although spaceborne (e.g. EO-1 Hyperion) hyperspectral data in the 0.4-2.5 micron (VSWIR) region are available, the provision of equivalent data in the log-wave infrared has lagged behind, there being no currently operational high spatial resolution LWIR imaging spectrometer on orbit. TIRCIS (Thermal Infra-Red Compact Imaging Spectrometer), uses a Fabry-Perot interferometer, an uncooled microbolometer array, and push-broom scanning to acquire hyperspectral image data. Radiometric calibration is provided by blackbody targets while spectral calibration is achieved using monochromatic light sources. The instrument has a mass of <15 kg and dimensions of 53 cm × 25 cm ♢ 22 cm, and has been designed to be compatible with integration into a micro-satellite platform. (A precursor to this instrument was launched onboard a 55 kg microsatellite in October 2015). The optical design yields a 120 m ground sample size given an orbit of 500 km. Over the wavelength interval of 7.5 to 14 microns up to 50 spectral samples are possible. Measured signal-to-noise ratios range from peak values of 500:1 to 1500:1, for source temperature of 10 to 100°C.

  2. TIRCIS: Hyperspectral Thermal Infrared Imaging Using a Small-Satellite Compliant Fourier-Transform Imaging Spectrometer, for Natural Hazard Applications

    Science.gov (United States)

    Wright, R.; Lucey, P. G.; Crites, S.; Garbeil, H.; Wood, M.

    2015-12-01

    Many natural hazards, including wildfires, volcanic eruptions, and, from the perspective of climate-related hazards, urban heat islands, could be better quantified via the routine availability of hyperspectral thermal infrared remote sensing data from orbit. However, no sensors are currently in operation that provide such data at high-to-moderate spatial resolution (e.g. Landsat-class resolution). In this presentation we will describe a prototype instrument, developed using funding provided by NASA's Instrument Incubator Program, that can make these important measurements. Significantly, the instrument has been designed such that its size, mass, power, and cost are consistent with its integration into small satellite platforms, or deployment as part of small satellite constellations. The instrument, TIRCIS (Thermal Infra-Red Compact Imaging Spectrometer), uses a Fabry-Perot interferometer, an uncooled microbolometer array, and push-broom scanning to acquire hyperspectral image data cubes. Radiometric calibration is provided by blackbody targets while spectral calibration is achieved using monochromatic light sources. Neither the focal plane nor the optics need to be cooled, and the instrument has a mass of <10 kg and dimensions of 53 cm × 25 cm × 22 cm. Although the prototype has four moving parts, this can easily be reduced to one. The current optical design yields a 120 m ground sample size given an orbit of 500 km. Over the wavelength interval of 7.5 to 14 microns up to 90 spectral samples are possible, by varying the physical design of the interferometer. Our performance model indicates signal-to-noise ratios of the order of about 200 to 300:1. In this presentation we will provide an overview of the instrument design, fabrication, results from our initial laboratory characterization, and some of the application areas in which small-satellite-ready instruments such as TIRCIS could make a valuable contribution to the study of natural hazards.

  3. The Composite Infrared Spectrometer

    Science.gov (United States)

    Calcutt, Simon; Taylor, Fredric; Ade, Peter; Kunde, Virgil; Jennings, Donald

    1992-01-01

    The Composite Infrared Spectrometer (CIRS) is a remote sensing instrument to be flown on the Cassini orbiter. It contains two Fourier transform spectrometers covering wavelengths of 7-1000 microns. The instrument is expected to have higher spectral resolution, smaller field of view, and better signal-to-noise performance than its counterpart, IRIS, on the Voyager missions. These improvements allow the study of the variability of the composition and temperature of the atmospheres of both Saturn and Titan with latitude, longitude and height, as well as allowing the possibility of discovery of previously undetected chemical species in these atmospheres. The long wavelengths accessible to CIRS allow sounding deeper into both atmospheres than was possible with IRIS.

  4. Static Fourier transform infrared spectrometer.

    Science.gov (United States)

    Schardt, Michael; Murr, Patrik J; Rauscher, Markus S; Tremmel, Anton J; Wiesent, Benjamin R; Koch, Alexander W

    2016-04-01

    Fourier transform spectroscopy has established itself as the standard method for spectral analysis of infrared light. Here we present a robust and compact novel static Fourier transform spectrometer design without any moving parts. The design is well suited for measurements in the infrared as it works with extended light sources independent of their size. The design is experimentally evaluated in the mid-infrared wavelength region between 7.2 μm and 16 μm. Due to its large etendue, its low internal light loss, and its static design it enables high speed spectral analysis in the mid-infrared.

  5. Mid infrared MEMS FTIR spectrometer

    Science.gov (United States)

    Erfan, Mazen; Sabry, Yasser M.; Mortada, Bassem; Sharaf, Khaled; Khalil, Diaa

    2016-03-01

    In this work we report, for the first time to the best of our knowledge, a bulk-micromachined wideband MEMS-based spectrometer covering both the NIR and the MIR ranges and working from 1200 nm to 4800 nm. The core engine of the spectrometer is a scanning Michelson interferometer micro-fabricated using deep reactive ion etching (DRIE) technology. The spectrum is obtained using the Fourier Transform techniques that allows covering a very wide spectral range limited by the detector responsivity. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator. Zirconium fluoride (ZrF4) multimode optical fibers are used to connect light between the white light source and the interferometer input, as well as the interferometer output to a PbSe photoconductive detector. The recorded signal-to-noise ratio is 25 dB at the wavelength of 3350 nm. The spectrometer is successfully used in measuring the absorption spectra of methylene chloride, quartz glass and polystyrene film. The presented solution provides a low cost method for producing miniaturized spectrometers in the near-/mid-infrared.

  6. Exploration of the Saturn System by the Cassini Mission: Observations with the Cassini Infrared Spectrometer

    Science.gov (United States)

    Abbas, Mian M.

    2014-01-01

    Outline: Introduction to the Cassini mission, and Cassini mission Objectives; Cassini spacecraft, instruments, launch, and orbit insertion; Saturn, Rings, and Satellite, Titan; Composite Infrared Spectrometer (CIRS); and Infrared observations of Saturn and titan.

  7. Objective Crystal Spectrometer on the SRG satellite

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Westergaard, Niels Jørgen Stenfeldt; Rasmussen, I.

    1994-01-01

    The flight version of the Objective Crystal Spectrometer (OXS) on the SPECTRUM-X- GAMMA satellite is presented. The spectrometer is a panel that is placed in front of one of the SODART telescopes. It is composed of an array of the three Bragg crystals, LiF(220), Si(111) and RAP(001) for high...

  8. Long-Wave Infrared Dyson Spectrometer

    Science.gov (United States)

    Johnson, William R.; Hook, Simon J.; Mouroulis, Pantazis Z.; Wilson, Daniel W.; Gunapala, Sarath D.; Hill, Cory J.; Mumolo, Jason M.; Eng, Bjorn T.

    2008-01-01

    Preliminary results are presented for an ultra compact long-wave infrared slit spectrometer based on the dyson concentric design. The dyson spectrometer has been integrated in a dewar environment with a quantum well infrared photodetecor (QWIP), concave electron beam fabricated diffraction grating and ultra precision slit. The entire system is cooled to cryogenic temperatures to maximize signal to noise ratio performance, hence eliminating thermal signal from transmissive elements and internal stray light. All of this is done while maintaining QWIP thermal control. A general description is given of the spectrometer, alignment technique and predicated performance. The spectrometer has been designed for optimal performance with respect to smile and keystone distortion. A spectral calibration is performed with NIST traceable targets. A 2-point non-uniformity correction is performed with a precision blackbody source to provide radiometric accuracy. Preliminary laboratory results show excellent agreement with modeled noise equivalent delta temperature and detector linearity over a broad temperature range.

  9. Fourier-Transform Infrared Spectrometer

    Science.gov (United States)

    Schindler, R. A.

    1986-01-01

    Fourier-transform spectrometer provides approximately hundredfold increase in luminosity at detector plane over that achievable with older instruments of this type. Used to analyze such weak sources as pollutants and other low-concentration substances in atmosphere. Interferometer creates fringe patterns on two distinct arrays of light detectors, which observe different wavelength bands. Objective lens focuses scene on image plane, which contains optical chopper. To make instrument less susceptible to variations in scene under observation, field and detector lenses focus entrance aperture, rather that image, onto detector array.

  10. Broadband Infrared Heterodyne Spectrometer: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, C G; Cunningham, C T; Tringe, J W

    2010-12-16

    This report summarizes the most important results of our effort to develop a new class of infrared spectrometers based on a novel broadband heterodyne design. Our results indicate that this approach could lead to a near-room temperature operation with performance limited only by quantum noise carried by the incoming signal. Using a model quantum-well infrared photodetector (QWIP), we demonstrated key performance features of our approach. For example, we directly measured the beat frequency signal generated by superimposing local oscillator (LO) light of one frequency and signal light of another through a spectrograph, by injecting the LO light at a laterally displaced input location. In parallel with the development of this novel spectrometer, we modeled a new approach to reducing detector volume though plasmonic resonance effects. Since dark current scales directly with detector volume, this ''photon compression'' can directly lead to lower currents. Our calculations indicate that dark current can be reduced by up to two orders of magnitude in an optimized ''superlens'' structure. Taken together, our spectrometer and dark current reduction strategies provide a promising path toward room temperature operation of a mid-wave and possibly long-wave infrared spectrometer.

  11. The Berkeley tunable far infrared laser spectrometers

    Science.gov (United States)

    Blake, G. A.; Laughlin, K. B.; Cohen, R. C.; Busarow, K. L.; Gwo, D.-H.

    1991-01-01

    A detailed description is presented for a tunable far infrared laser spectrometer based on frequency mixing of an optically pumped molecular gas laser with tunable microwave radiation in a Schottky point contact diode. The system has been operated on over 30 laser lines in the range 10-100/cm and exhibits a maximum absorption sensitivity near one part in a million. Each laser line can be tuned by + or - 110 GHz with first-order sidebands.

  12. Miniature high-performance infrared spectrometer for space applications

    Science.gov (United States)

    Kruzelecky, Roman V.; Haddad, Emile; Wong, Brian; Lafrance, Denis; Jamroz, Wes; Ghosh, Asoke K.; Zheng, Wanping; Phong, Linh

    2004-06-01

    Infrared spectroscopy probes the characteristic vibrational and rotational modes of chemical bonds in molecules to provide information about both the chemical composition and the bonding configuration of a sample. The significant advantage of the Infrared spectral technique is that it can be used with minimal consumables to simultaneously detect a large variety of chemical and biochemical species with high chemical specificity. To date, relatively large Fourier Transform (FT-IR) spectrometers employing variations of the Michelson interferometer have been successfully employed in space for various IR spectroscopy applications. However, FT-IR systems are mechanically complex, bulky (> 15 kg), and require considerable processing. This paper discusses the use of advanced integrated optics and smart optical coding techniques to significantly extend the performance of miniature IR spectrometers by several orders of magnitude in sensitivity. This can provide the next-generation of compact, high-performance IR spectrometers with monolithically integrated optical systems for robust optical alignment. The entire module can weigh under 3 kg to minimize the mass penalty for space applications. Miniaturized IR spectrometers are versatile and very convenient for small and micro satellite based missions. They can be dedicated to the monitoring of the CO2 in an Earth Observation mission, to Mars exobiology exploration, as well as to vital life support in manned space system; such as the cabin air quality and the quality of the recycled water supply.

  13. Composite Infrared Spectrometer (CIRS) on Cassini

    Science.gov (United States)

    Jennings, Donald E.; Flasar, F. M.; Kunde, V. G.; Nixon, C. A.; Segura, M. E.; Romani, P. N.; Gorius, N.; Albright, S.; Brasunas, J. C.; Carlson, R. C.; hide

    2017-01-01

    The Cassini spacecraft orbiting Saturn carries the composite infrared spectrometer (CIRS) designed to study thermal emission from Saturn and its rings and moons. CIRS, a Fourier transform spectrometer, is an indispensable part of the payload providing unique measurements and important synergies with the other instruments. It takes full advantage of Cassini's 13-year-long mission and surpasses the capabilities of previous spectrometers on Voyager 1 and 2. The instrument, consisting of two interferometers sharing a telescope and a scan mechanism, covers over a factor of 100 in wavelength in the mid and far infrared. It is used to study temperature, composition, structure, and dynamics of the atmospheres of Jupiter, Saturn, and Titan, the rings of Saturn, and surfaces of the icy moons. CIRS has returned a large volume of scientific results, the culmination of over 30 years of instrument development, operation, data calibration, and analysis. As Cassini and CIRS reach the end of their mission in 2017, we expect that archived spectra will be used by scientists for many years to come.

  14. Near-infrared imaging spectrometer onboard NEXTSat-1

    Science.gov (United States)

    Jeong, Woong-Seob; Park, Sung-Joon; Moon, Bongkon; Lee, Dae-Hee; Pyo, Jeonghyun; Park, Won-Kee; Park, Youngsik; Kim, Il-Joong; Ko, Kyeongyeon; Lee, Dukhang; Kim, Min Gyu; Kim, Minjin; Ko, Jongwan; Shin, Goo-Hwan; Chae, Jangsoo; Matsumoto, Toshio

    2016-07-01

    The NISS (Near-infrared Imaging Spectrometer for Star formation history) is the near-infrared instrument optimized to the first next generation of small satellite (NEXTSat-1) in Korea. The spectro-photometric capability in the near-infrared range is a unique function of the NISS. The major scientific mission is to study the cosmic star formation history in local and distant universe. For those purposes, the NISS will perform the large areal imaging spectroscopic survey for astronomical objects and low background regions. We have paid careful attention to reduce the volume and to increase the total throughput. The newly implemented off-axis optics has a wide field of view (2° x 2°) and a wide wavelength range from 0.9 to 3.8μm. The mechanical structure is designed to consider launching conditions and passive cooling of the telescope. The compact dewar after relay-lens module is to operate the infrared detector and spectral filters at 80K stage. The independent integration of relay-lens part and primary-secondary mirror assembly alleviates the complex alignment process. We confirmed that the telescope and the infrared sensor can be cooled down to around 200K and 80K, respectively. The engineering qualification model of the NISS was tested in the space environment including the launch-induced vibration and shock. The NISS will be expected to demonstrate core technologies related to the development of the future infrared space telescope in Korea.

  15. TIRSPEC : TIFR Near Infrared Spectrometer and Imager

    CERN Document Server

    Ninan, J P; Ghosh, S K; D'Costa, S L A; Naik, M B; Poojary, S S; Sandimani, P R; Meshram, G S; Jadhav, R B; Bhagat, S B; Gharat, S M; Bakalkar, C B; Prabhu, T P; Anupama, G C; Toomey, D W

    2014-01-01

    We describe the TIFR Near Infrared Spectrometer and Imager (TIRSPEC) designed and built in collaboration with M/s. Mauna Kea Infrared LLC, Hawaii, USA, now in operation on the side port of the 2-m Himalayan Chandra Telescope (HCT), Hanle (Ladakh), India at an altitude of 4500 meters above mean sea level. The TIRSPEC provides for various modes of operation which include photometry with broad and narrow band filters, spectrometry in single order mode with long slits of 300" length and different widths, with order sorter filters in the Y, J, H and K bands and a grism as the dispersing element as well as a cross dispersed mode to give a coverage of 1.0 to 2.5 microns at a resolving power R of ~1200. The TIRSPEC uses a Teledyne 1024 x 1024 pixel Hawaii-1 PACE array detector with a cutoff wavelength of 2.5 microns and on HCT, provides a field of view of 307" x 307" with a plate scale of 0.3"/pixel. The TIRSPEC was successfully commissioned in June 2013 and the subsequent characterization and astronomical observatio...

  16. Tables of wavenumbers for the calibration of infrared spectrometers

    CERN Document Server

    Cole, ARH

    1977-01-01

    Tables of Wavenumbers for the Calibration of Infrared Spectrometers, Second Edition is a compilation of tables of wavenumber values for the calibration of infrared spectrometers. It makes the best use of high resolution results and integrates the far infrared data with the higher frequency values. This book is organized in two parts, one for high to medium-resolution spectrometers used by physical chemists and physicists, and the other for medium to low-resolution instruments employed by organic and inorganic chemists. The first part includes tables of wavenumber of infrared absorption lines

  17. Satellite and lunar laser ranging in infrared

    Science.gov (United States)

    Courde, Clement; Torre, Jean-Marie; Samain, Etienne; Martinot-Lagarde, Gregoire; Aimar, Mourad; Albanese, Dominique; Maurice, Nicolas; Mariey, Hervé; Viot, Hervé; Exertier, Pierre; Fienga, Agnes; Viswanathan, Vishnu

    2017-05-01

    We report on the implementation of a new infrared detection at the Grasse lunar laser ranging station and describe how infrared telemetry improves the situation. We present our first results on the lunar reflectors and show that infrared detection permits us to densify the observations and allows measurements during the new and the full moon periods. We also present the benefit obtained on the ranging of Global Navigation Satellite System (GNSS) satellites and on RadioAstron which have a very elliptic orbit.

  18. Cloud and Thermodynamic Parameters Retrieved from Satellite Ultraspectral Infrared Measurements

    Science.gov (United States)

    Zhou, Daniel K.; Smith, William L.; Larar, Allen M.; Liu, Xu; Taylor, Jonathan P.; Schluessel, Peter; Strow, L. Larrabee; Mango, Stephen A.

    2008-01-01

    Atmospheric-thermodynamic parameters and surface properties are basic meteorological parameters for weather forecasting. A physical geophysical parameter retrieval scheme dealing with cloudy and cloud-free radiance observed with satellite ultraspectral infrared sounders has been developed and applied to the Infrared Atmospheric Sounding Interferometer (IASI) and the Atmospheric InfraRed Sounder (AIRS). The retrieved parameters presented herein are from radiance data gathered during the Joint Airborne IASI Validation Experiment (JAIVEx). JAIVEx provided intensive aircraft observations obtained from airborne Fourier Transform Spectrometer (FTS) systems, in-situ measurements, and dedicated dropsonde and radiosonde measurements for the validation of the IASI products. Here, IASI atmospheric profile retrievals are compared with those obtained from dedicated dropsondes, radiosondes, and the airborne FTS system. The IASI examples presented here demonstrate the ability to retrieve fine-scale horizontal features with high vertical resolution from satellite ultraspectral sounder radiance spectra.

  19. Infrared Spectroscopy with a Cavity Ring-Down Spectrometer

    Science.gov (United States)

    2014-08-01

    Fourier transform infrared spectroscopy ( FTIR ) measures the transmission of the excitation source and then calculates the absorption from that measured...laser FTIR Fourier transform infrared spectroscopy HgCdTe mercury, cadmium, tellurium I absorbed light intensity I0 initial light intensity l...Infrared Spectroscopy with a Cavity Ring-Down Spectrometer by Logan S Marcus, Ellen L Holthoff, and Paul M Pellegrino ARL-TR-7031 August

  20. Dedicated monolithic infrared spectrometer for process monitoring

    Science.gov (United States)

    Chadha, Suneet; Kyle, William; Bolduc, Roy A.; Curtiss, Lawrence E.

    1999-12-01

    Foster-Miller has leveraged its innovations in IR fiber- optic probes and the recent development of a miniature spectrometer to build a novel IR sensor system for process applications. The developed sensor systems is a low-cost alternative to process FTIR and filter based systems. A monolithic wedge-grating optic provides the spectral dispersion with low cost thermopile point or array detectors picking off the diffracted wavelengths from the optic. The integrated optic provides spectral discrimination between 3- 12 micrometers with resolution at 8 cm-1 or better and high overall optical throughput. The device has a fixed cylindrical grating uniquely bonded to the edge of a ZnSe conditioning 'wedge'. The conditioning optic overcomes limitations of concave gratings as it accepts high angle light at the narrow end of the wedge and progressively conditions it to be near normal to the grating. On return, the diffracted wavelengths are concentrated on the discrete or array detector elements by the wedge, providing throughput comparable to that of an FTIR. The miniature spectrometer coupled to flow through liquid cells or multipass gas cells provides significant cost advantage over conventional sampling methodologies. Currently, we are investigating process applications for the petroleum and dairy markets. The sensor system eliminates the cost, complexity, reliability and bandwidth/resolution problems associated with either Fabry Perot or Michelson Interferometer based approaches for low-cost process applications.

  1. Exploring the Saturn System in the Thermal Infrared: The Composite Infrared Spectrometer

    Science.gov (United States)

    Flasar, F. M.; Kunde, V. g.; Abbas, M. M.; Achterberg, R. K.; Ade, P.; Barucci, A.; Bezard, B.; Bjoraker, G. L.; Brasunas, J. C.; Calcutt, S.

    2004-01-01

    The Composite Inbred Spectrometer (CIRS) is a remote-sensing Fourier Transform Spectrometer on the Cassini orbiter that measures thermal radiation over two decades in wave number, from 10 to 1400 cm (1 mm to 7pm), with a spectral resolution that can be set from 0.5 to 20 cm. The far in portion of the spectrum (10 - 600 cm) is measured with a polarizing interferometer having thermopile detectors with a common 4-mrad field of view. The middle infrared portion is measured with a traditional Michelson interferometer having two focal planes (600 - 1100cm, 1100-1400 cm). Each focal plane is composed of a 1x10 array of HgCdTe detectors, each detector having a 0.3-mrad field of view. CIRS observations will provide three-dimensional maps of temperature, gas composition, and aerosols/condensates of the atmospheres of Titan and Saturn with good vertical and horizontal resolution, from deep in their tropospheres to high in their mesospheres. CIRS ability to observe atmospheres in the limb viewing mode (in addition to nadir) offers the opportunity to provide accurate and highly resolved vertical profiles of these atmospheric variables. The ability to observe with high-spectral resolution should facilitate the identification of new constituents. CIRS will also map the thermal and compositional properties of the surfaces of Saturn's icy satellites. It will similarly map Saturn's rings, characterizing their formation and evolution. The combination of broad spectral range, programmable spectral resolution, the small detector fields of view, and an orbiting spacecraft platform will allow CIRS to observe the Saturnian system in the thermal infrared at a level of detail not previously achieved.

  2. Spaceborne infrared Fourier-transform spectrometers for temperature and humidity sounding of the Earth's atmosphere

    Science.gov (United States)

    Golovin, Yu. M.; Zavelevich, F. S.; Nikulin, A. G.; Kozlov, D. A.; Monakhov, D. O.; Kozlov, I. A.; Arkhipov, S. A.; Tselikov, V. A.; Romanovskii, A. S.

    2014-12-01

    A spaceborne Fourier-transform infrared (FTIR) spectrometer was designed for measuring the spectra of the outgoing Earth's atmosphere radiation and serves for providing for the needs of online meteorology and climatology with regard to obtaining the following kinds of data: vertical profiles of temperature and humidity profiles in the troposphere and the lower stratosphere, the general and altitudinal ozone distribution, concentrations of small gaseous constituents, temperature of the underlying surface, etc. At present, works are underway at the Keldysh Research Centre for creating IKFS-series FTIR spectrometers for satellites in Sun-synchronous orbits: the IKFS-2 instrument for the Meteor-M spacecraft no. 2 of the Meteor-3M space complex (developed and supplied for testing together with the spacecraft) and an advanced IKFS-3 instrument for the Meteor-MP fourth-generation hydrometeorological and oceanographic space complex for Earth monitoring (at the developmental stage). The composition, functional diagram, and technical specifications of the FTIR spectrometers are presented.

  3. Imaging telescope-spectrometer for infrared sky surveys

    Science.gov (United States)

    Maslov, Igor A.; Sholomitskii, Gennadii B.; Kuznetsov, Arkadii E.; Patrashin, Michail A.; Olejnikov, Leonid S.

    1995-06-01

    A new type of imaging telescope-spectrometer for surviving the sky aboard a satellite is described. A static Michelson interferometer in front of an objective with 2D-arrays in its focal plane is capable of providing interferograms both for point and extended sources. As an example, the telescope-spectrometer based on the 15-cm telescope of the IKON project and a plane-parallel Ge plate as a beamsplitter may have approximately equals 30 cm(superscript -1 spectral resolution in the range 3 - 20 micrometers . For higher resolution, such an objective interferometer has advantage over a dispersion spectrometer in the signal-to-noise ratio and is free from the disadvantage of an objective prism not providing spectra of extended sources.

  4. [Biological Process Oriented Online Fourier Transform Infrared Spectrometer].

    Science.gov (United States)

    Xie, Fei; Wu, Qiong-shui; Zeng, Li-bo

    2015-08-01

    An online Fourier Transform Infrared Spectrometer and an ATR (Attenuated Total Reflection) probe, specifically at the application of real time measurement of the reaction substrate concentration in biological processes, were designed. (1) The spectrometer combined the theories of double cube-corner reflectors and flat mirror, which created a kind of high performance interferometer system. The light path folding way was utilized to makes the interferometer compact structure. Adopting double cube-corner reflectors, greatly reduces the influence of factors in the process of moving mirror movement such as rotation, tilt, etc. The parallelogram oscillation flexible support device was utilized to support the moving mirror moves. It cancelled the friction and vibration during mirror moving, and ensures the smooth operation. The ZnSe splitter significantly improved the hardware reliability in high moisture environment. The method of 60° entrance to light splitter improves the luminous flux. (2) An ATR in situ measuring probe with simple structure, large-flux, economical and practical character was designed in this article. The transmission of incident light and the light output utilized the infrared pipe with large diameter and innerplanted-high plating membrane, which conducted for the infrared transmission media of ATR probe. It greatly reduced the energy loss of infrared light after multiple reflection on the inner wall of the light pipe. Therefore, the ATR probe obtained high flux, improved the signal strength, which make the signal detected easily. Finally, the high sensitivity of MCT (Mercury Cadmium Telluride) detector was utilized to realize infrared interference signal collection, and improved the data quality of detection. The test results showed that the system yields the advantages of perfect moisture-proof performance, luminous flux, online measurement, etc. The designed online Fourier infrared spectrometer can real-time measured common reactant substrates

  5. Mid-Infrared Frequency Comb Fourier Transform Spectrometer

    CERN Document Server

    Adler, Florian; Foltynowicz, Aleksandra; Cossel, Kevin C; Briles, Travis C; Hartl, Ingmar; Ye, Jun

    2010-01-01

    Optical frequency-comb-based-high-resolution spectrometers offer enormous potential for spectroscopic applications. Although various implementations have been demonstrated, the lack of suitable mid-infrared comb sources has impeded explorations of molecular fingerprinting. Here we present for the first time a frequency-comb Fourier transform spectrometer operating in the 2100-to-3700-cm-1 spectral region that allows fast and simultaneous acquisitions of broadband absorption spectra with up to 0.0056 cm-1 resolution. We demonstrate part-per-billion detection limits in 30 seconds of integration time for various important molecules including methane, ethane, isoprene, and nitrous oxide. Our system enables precise concentration measurements even in gas mixtures that exhibit continuous absorption bands, and it allows detection of molecules at levels below the noise floor via simultaneous analysis of multiple spectral features. This system represents a near real-time, high-resolution, high-bandwidth mid-infrared sp...

  6. An Airborne Infrared Spectrometer for Solar Eclipse Observations

    Science.gov (United States)

    Samra, Jenna; DeLuca, Edward E.; Golub, Leon; Cheimets, Peter; Philip, Judge

    2016-05-01

    The airborne infrared spectrometer (AIR-Spec) is an innovative solar spectrometer that will observe the 2017 solar eclipse from the NSF/NCAR High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER). AIR-Spec will image five infrared coronal emission lines to determine whether they may be useful probes of coronal magnetism.The solar magnetic field provides the free energy that controls coronal heating, structure, and dynamics. Energy stored in coronal magnetic fields is released in flares and coronal mass ejections and ultimately drives space weather. Therefore, direct coronal field measurements have significant potential to enhance understanding of coronal dynamics and improve solar forecasting models. Of particular interest are observations of field lines in the transitional region between closed and open flux systems, providing important information on the origin of the slow solar wind.While current instruments routinely observe only the photospheric and chromospheric magnetic fields, AIR-Spec will take a step toward the direct observation of coronal fields by measuring plasma emission in the infrared at high spatial and spectral resolution. During the total solar eclipse of 2017, AIR-Spec will observe five magnetically sensitive coronal emission lines between 1.4 and 4 µm from the HIAPER Gulfstream V at an altitude above 14.9 km. The instrument will measure emission line intensity, width, and Doppler shift, map the spatial distribution of infrared emitting plasma, and search for waves in the emission line velocities.AIR-Spec consists of an optical system (feed telescope, grating spectrometer, and infrared detector) and an image stabilization system, which uses a fast steering mirror to correct the line-of-sight for platform perturbations. To ensure that the instrument meets its research goals, both systems are undergoing extensive performance modeling and testing. These results are shown with reference to the science requirements.

  7. Geodetic Mobil Solar Spectrometer for JASON Altimeter Satellite Calibration

    Science.gov (United States)

    Somieski, A.; Buerki, B.; Geiger, A.; Kahle, H.-G.; Becker-Ross, H.; Florek, S.; Okruss, M.

    Atmospheric water vapor is a crucial factor in achieving highest accuracies for space geodetic measurements. Water vapor causes a delay of the propagation time of the altimeter satellite signal, which propagates into errors for the determination of surface heights. Knowledge of the precipitable water vapor (PW) enables a tropospheric correction of the satellite signal. Therefore, different remote sensing techniques have been pursued to measure the PW continuously. The prototype Geodetic Mobil Solar Spectrometer (GEMOSS) was developed at the Geodesy and Geodynamics Laboratory (GGL, ETH Zurich) in cooperation with the Institute of Spectrochemistry and Applied Spectroscopy (ISAS) (Berlin, Germany). A new optical approach allows the simultaneous measurement of numerous single absorption lines of water vapor in the wide range between 728 nm and 915 nm. The large number of available absorption lines increases the accuracy of the absolute PW retrievals considerably. GEMOSS has been deployed during two campaigns in Greece in the framework of the EU-project GAVDOS, which deals with the calibration of the altimeter satellite JASON. During the overfly of JASON, the ground-based determination of PW enables the correction of the satellite measurements due to tropospheric water vapor. Comparisons with radiometer and radiosondes data allow to assess the accuracy and reliability of GEMOSS. The instrumental advancement of GEMOSS is presented together with the results of the campaigns carried out.

  8. Calibration of the spectrometer aboard the INTEGRAL satellite

    Science.gov (United States)

    Schanne, Stephane; Cordier, Bertrand; Gros, Maurice; Attie, David; von Ballmoos, Peter; Bouchet, Laurent; Carli, Raffaelo; Connell, Paul; Diehl, Roland; Jean, Pierre; Kiener, Juergen; von Kienlin, Andreas; Knoedlseder, Juergen; Laurent, Phillipe; Lichti, Giselher G.; Mandrou, Pierre; Paul, Jaques; Paul, Philippe; Roques, Jean-Pierre; Sanchez, Filomeno; Schoenfelder, Volker; Shrader, Chris; Skinner, Gerald K.; Strong, Andrew W.; Sturner, Steven J.; Tatischeff, Vincent; Teegarden, Bonnard J.; Vedrenne, Gilbert; Weidenspointner, Georg; Wunderer, Cornelia B.

    2003-03-01

    SPI, the Spectrometer on board the ESA INTEGRAL satellite, to be launched in October 2002, will study the gamma-ray sky in the 20 keV to 8 MeV energy band with a spectral resolution of 2 keV for photons of 1 MeV, thanks to its 19 germanium detectors spanning an active area of 500 cm2. A coded mask imaging technique provides a 2° angular resolution. The 16° field of view is defined by an active BGO veto shield, furthermore used for background rejection. In April 2001 the flight model of SPI underwent a one-month calibration campaign at CEA in Bruyères le Châtel using low intensity radioactive sources and the CEA accelerator for homogeneity measurements and high intensity radioactive sources for imaging performance measurements. After integration of all scientific payloads (the spectrometer SPI, the imager IBIS and the monitors JEM-X and OMC) on the INTEGRAL satellite, a cross-calibration campaign has been performed at the ESA center in Noordwijk. A set of sources has been placed in the field of view of the different instruments in order to compare their performances and determine their mutual influence. We report on the scientific goals of this calibration activity, and present the measurements performed as well as some preliminary results.

  9. The Cosmic Infrared Background Experiment (CIBER): the Narrow Band Spectrometer

    CERN Document Server

    Korngut, P M; Arai, T; Battle, J; Bock, J; Brown, S W; Cooray, A; Hristov, V; Keating, B; Kim, M G; Lanz, A; Lee, D H; Levenson, L R; Lykke, K R; Mason, P; Matsumoto, T; Matsuura, S; Nam, U W; Shultz, B; Smith, A W; Sullivan, I; Tsumura, K; Wada, T; Zemcov, M

    2013-01-01

    We have developed a near-infrared spectrometer designed to measure the absolute intensity of the Solar 854.2 nm CaII Fraunhofer line, scattered by interplanetary dust, in the Zodiacal light spectrum. Based on the known equivalent line width in the Solar spectrum, this measurement can derive the Zodiacal brightness, testing models of the Zodiacal light based on morphology that are used to determine the extragalactic background light in absolute photometry measurements. The spectrometer is based on a simple high-resolution tipped filter placed in front of a compact camera with wide-field refractive optics to provide the large optical throughput and high sensitivity required for rocket-borne observations. We discuss the instrument requirements for an accurate measurement of the absolute Zodiacal light brightness, the measured laboratory characterization, and the instrument performance in flight.

  10. Analysis and System Design Framework for Infrared Spatial Heterodyne Spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, B.J.; Smith, B.W.; Laubscher, B.E.; Villeneuve, P.V.; Briles, S.D.

    1999-04-05

    The authors present a preliminary analysis and design framework developed for the evaluation and optimization of infrared, Imaging Spatial Heterodyne Spectrometer (SHS) electro-optic systems. Commensurate with conventional interferometric spectrometers, SHS modeling requires an integrated analysis environment for rigorous evaluation of system error propagation due to detection process, detection noise, system motion, retrieval algorithm and calibration algorithm. The analysis tools provide for optimization of critical system parameters and components including : (1) optical aperture, f-number, and spectral transmission, (2) SHS interferometer grating and Littrow parameters, and (3) image plane requirements as well as cold shield, optical filtering, and focal-plane dimensions, pixel dimensions and quantum efficiency, (4) SHS spatial and temporal sampling parameters, and (5) retrieval and calibration algorithm issues.

  11. Stratospheric ozone measurement with an infrared heterodyne spectrometer

    Science.gov (United States)

    Abbas, M. M.; Kostiuk, T.; Mumma, M. J.; Buhl, D.; Kunde, V. G.; Brown, L. W.

    1978-01-01

    Measurements of a stratospheric ozone concentration profile are made by detecting infrared absorption lines with a heterodyne spectrometer. The infrared spectrometer is based on a line-by-line tunable CO2 lasers, a liquid-nitrogen cooled HgCdTe photomixer, and a 64-channel spectral line receiver. The infrared radiation from the source is mixed with local-oscillator radiation. The difference frequency signal in a bandwidth above and below the local-oscillator frequency is detected. The intensity in each sideband is found by subtracting sideband contributions. It is found that absolute total column density is 0.32 plus or minus 0.02 cm-atm with a peak mixing ratio at about 24 km. The (7,1,6)-(7,1,7) O3 line center frequency is identified as 1043.1772/cm. Future work will involve a number of ozone absorption lines and measurements of diurnal variation. Completely resolved stratospheric lines may be inverted to yield concentration profiles of trace constituents and stratospheric gases.

  12. A new generation of MEMS middle-infrared spectrometers

    Science.gov (United States)

    Otto, Thomas; Saupe, Ray; Stock, Volker; Seider, Thomas; Gessner, Thomas

    2014-03-01

    Mid infrared spectroscopy has been developed to a powerful and essential method of material analysis, with a steadily increasing number of industrial and scientific application fields. The so called spectral fingerprint range enables identification of chemical compounds by their unique spectral pattern. To provide a suitable miniaturized and portable MIR spectrometer solution at an affordable price, an existing MEMS NIR spectrometer module which already bases on micro system technology has been expanded in its wavelength range. The developed spectrometer belongs to the category of scanning grating spectrometers. Main component is a fast oscillating micro-mirror which moves sinusoidal with high mechanical precision enabling a high stability of according wavelength axis. This is supported by a highly precise optical tracking of the actual motion. Mono-crystalline silicon guarantees a long-life operation with no wear even under harsh environmental conditions. Spectral signal acquisition is realized by using a TE-cooled MCT single element detector assisted by low noise trans-impedance amplifier. With the help of integrated logic components a data pre-processing takes place, such as averaging, offset subtraction, detector transfer characteristic correction and noise shaping. Due the compact and flexible setup, the spectrometer is suitable for the use in various applications, such as process control in chemical industry, gas mixture analysis or liquid verification. The portability of the device opens up new application possibilities in mobile environment. The advances of the promising technology and its specific applications will be described in this paper. Advanced performance issues of the device be reviewed in detail.

  13. A high-resolution Fourier-transform infrared spectrometer.

    Science.gov (United States)

    Johnson, H. L.; Forbes, F. F.; Thompson, R. I.; Steinmetz , D. L.; Harris, O.

    1973-01-01

    We have developed a Fourier-transform infrared spectrometer having a resolution of 0.5/cm over the range of wavelength from 1 to 5.5 microns. It has been used to observe the sun over this wavelength range from a Lear Jet flying at an altitude of 14 km, and to observe a number of stars from the ground, using the 229-cm telescope of the Steward Observatory and the 152-cm aluminum-mirror telescope at the Observatorio Astronomico Nacional in the Sierra de San Pedro Martir, Baja California, Mexico. The solar spectrum is given here, while the ground-based spectra are being published separately.

  14. The Cosmic Infrared Background Experiment (CIBER): The Low Resolution Spectrometer

    CERN Document Server

    Tsumura, K; Battle, J; Bock, J; Brown, S; Cooray, A; Hristov, V; Keating, B; Kim, M G; Lee, D H; Levenson, L R; Lykke, K; Mason, P; Matsumoto, T; Matsuura, S; Murata, K; Nam, U W; Renbarger, T; Smith, A; Sullivan, I; Suzuki, K; Wada, T; Zemcov, M

    2011-01-01

    Absolute spectrophotometric measurements of diffuse radiation at 1 \\mu m to 2 \\mu m are crucial to our understanding of the radiative content of the Universe from nucleosynthesis since the epoch of reionization, the composition and structure of the Zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment (CIBER) is a \\lambda / \\Delta \\lambda \\sim 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 \\mu m < \\lambda < 2.1 \\mu m. This paper presents the optical, mechanical and electronic design of the LRS, as well as the ground testing, characterization and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding a...

  15. Near-Infrared Grating Spectrometer for Mobile Phone Applications.

    Science.gov (United States)

    Pügner, Tino; Knobbe, Jens; Grüger, Heinrich

    2016-05-01

    Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro-electro-mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm(3) Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications.

  16. The Infrared Astronomical Satellite (IRAS) mission

    Science.gov (United States)

    Neugebauer, G.; Habing, H. J.; Van Duinen, R.; Aumann, H. H.; Beichman, C. A.; Baud, B.; Beintema, D. A.; Boggess, N.; Clegg, P. E.; De Jong, T.

    1984-01-01

    The Infrared Astronomical Satellite (IRAS) consists of a spacecraft and a liquid helium cryostat that contains a cooled IR telescope. The telescope's focal plane assembly is cooled to less than 3 K, and contains 62 IR detectors in the survey array which are arranged so that every source crossing the field of view can be seen by at least two detectors in each of four wavelength bands. The satellite was launched into a 900 km-altitude near-polar orbit, and its cryogenic helium supply was exhausted on November 22, 1983. By mission's end, 72 percent of the sky had been observed with three or more hours-confirming scans, and 95 percent with two or more hours-confirming scans. About 2000 stars detected at 12 and 25 microns early in the mission, and identified in the SAO (1966) catalog, have a positional uncertainty ellipse whose axes are 45 x 9 arcsec for an hours-confirmed source.

  17. JIRAM, the image spectrometer in the near infrared on board the Juno mission to Jupiter.

    Science.gov (United States)

    Adriani, Alberto; Coradini, Angioletta; Filacchione, Gianrico; Lunine, Jonathan I; Bini, Alessandro; Pasqui, Claudio; Calamai, Luciano; Colosimo, Fedele; Dinelli, Bianca M; Grassi, Davide; Magni, Gianfranco; Moriconi, Maria L; Orosei, Roberto

    2008-06-01

    The Jovian InfraRed Auroral Mapper (JIRAM) has been accepted by NASA for inclusion in the New Frontiers mission "Juno," which will launch in August 2011. JIRAM will explore the dynamics and the chemistry of Jupiter's auroral regions by high-contrast imaging and spectroscopy. It will also analyze jovian hot spots to determine their vertical structure and infer possible mechanisms for their formation. JIRAM will sound the jovian meteorological layer to map moist convection and determine water abundance and other constituents at depths that correspond to several bars pressure. JIRAM is equipped with a single telescope that accommodates both an infrared camera and a spectrometer to facilitate a large observational flexibility in obtaining simultaneous images in the L and M bands with the spectral radiance over the central zone of the images. Moreover, JIRAM will be able to perform spectral imaging of the planet in the 2.0-5.0 microm interval of wavelengths with a spectral resolution better than 10 nm. Instrument design, modes, and observation strategy will be optimized for operations onboard a spinning satellite in polar orbit around Jupiter. The JIRAM heritage comes from Italian-made, visual-infrared imaging spectrometers dedicated to planetary exploration, such as VIMS-V on Cassini, VIRTIS on Rosetta and Venus Express, and VIR-MS on the Dawn mission.

  18. Calibration of the AKARI Far-Infrared Imaging Fourier Transform Spectrometer

    CERN Document Server

    Murakami, Noriko; Takahashi, Hidenori; Okada, Yoko; Yasuda, Akiko; Ootsubo, Takafumi; Kaneda, Hidehiro; Matsuo, Hiroshi; Baluteau, Jean-Paul; Davis-Imhof, Peter; Gom, Brad G; Naylor, David A; Zavagno, Annie; Yamamura, Issei; Matsuura, Shuji; Shirahata, Mai; Doi, Yasuo; Nakagawa, Takao; Shibai, Hiroshi

    2010-01-01

    The Far-Infrared Surveyor (FIS) onboard the AKARI satellite has a spectroscopic capability provided by a Fourier transform spectrometer (FIS-FTS). FIS-FTS is the first space-borne imaging FTS dedicated to far-infrared astronomical observations. We describe the calibration process of the FIS-FTS and discuss its accuracy and reliability. The calibration is based on the observational data of bright astronomical sources as well as two instrumental sources. We have compared the FIS-FTS spectra with the spectra obtained from the Long Wavelength Spectrometer (LWS) of the Infrared Space Observatory (ISO) having a similar spectral coverage. The present calibration method accurately reproduces the spectra of several solar system objects having a reliable spectral model. Under this condition the relative uncertainty of the calibration of the continuum is estimated to be $\\pm$ 15% for SW, $\\pm$ 10% for 70-85 cm^(-1) of LW, and $\\pm$ 20% for 60-70 cm^(-1) of LW; and the absolute uncertainty is estimated to be +35/-55% for...

  19. Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Connor J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Radiation Measurement (ARM) Program

    2016-03-01

    The Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST) measures the absolute infrared (IR) spectral radiance (watts per square meter per steradian per wavenumber) of the sky directly above the instrument. More information about the instrument can be found through the manufacturer’s website. The spectral measurement range of the instrument is 3300 to 520 wavenumbers (cm-1) or 3-19.2 microns for the normal-range instruments and 3300 to 400 cm-1 or 3-25 microns, for the extended-range polar instruments. Spectral resolution is 1.0 cm-1. Instrument field-of-view is 1.3 degrees. Calibrated sky radiance spectra are produced on cycle of about 141 seconds with a group of 6 radiance spectra zenith having dwell times of about 14 seconds each interspersed with 55 seconds of calibration and mirror motion. The ASSIST data is comparable to the Atmospheric Emitted Radiance Interferometer (AERI) data and can be used for 1) evaluating line-by-line radiative transport codes, 2) detecting/quantifying cloud effects on ground-based measurements of infrared spectral radiance (and hence is valuable for cloud property retrievals), and 3) calculating vertical atmospheric profiles of temperature and water vapor and the detection of trace gases.

  20. The Cosmic Infrared Background Experiment (CIBER): The Low Resolution Spectrometer

    Science.gov (United States)

    Tsumura, K.; Arai, T.; Battle, J.; Bock, J.; Brown, S.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lee, D. H.; Levenson, L. R.; Lykke, K.; Mason, P.; Matsumoto, T.; Matsuura, S.; Murata, K.; Nam, U. W.; Renbarger, T.; Smith, A.; Sullivan, I.; Suzuki, K.; Wada, T.; Zemcov, M.

    2013-08-01

    Absolute spectrophotometric measurements of diffuse radiation at 1 μm to 2 μm are crucial to our understanding of the radiative content of the universe from nucleosynthesis since the epoch of reionization, the composition and structure of the zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment is a λ/Δλ ~ 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 μm <λ < 2.1 μm. This paper presents the optical, mechanical, and electronic design of the LRS, as well as the ground testing, characterization, and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding and control of sources of systematic error for absolute photometry of the near-infrared extragalactic background light.

  1. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): THE LOW RESOLUTION SPECTROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Tsumura, K.; Arai, T.; Matsumoto, T.; Matsuura, S.; Murata, K. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronoutical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Battle, J.; Bock, J. [Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA), Pasadena, CA 91109 (United States); Brown, S.; Lykke, K.; Smith, A. [Optical Technology Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Cooray, A. [Center for Cosmology, University of California, Irvine, Irvine, CA 92697 (United States); Hristov, V.; Levenson, L. R.; Mason, P. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Keating, B.; Renbarger, T. [Department of Physics, University of California, San Diego, San Diego, CA 92093 (United States); Kim, M. G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, D. H.; Nam, U. W. [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Sullivan, I., E-mail: tsumura@ir.isas.jaxa.jp [Department of Physics, The University of Washington, Seattle, WA 98195 (United States); and others

    2013-08-15

    Absolute spectrophotometric measurements of diffuse radiation at 1 {mu}m to 2 {mu}m are crucial to our understanding of the radiative content of the universe from nucleosynthesis since the epoch of reionization, the composition and structure of the zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment is a {lambda}/{Delta}{lambda} {approx} 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 {mu}m <{lambda} < 2.1 {mu}m. This paper presents the optical, mechanical, and electronic design of the LRS, as well as the ground testing, characterization, and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding and control of sources of systematic error for absolute photometry of the near-infrared extragalactic background light.

  2. THIS: a tuneable heterodyne infrared spectrometer for SOFIA

    Science.gov (United States)

    Schieder, R.; Sonnabend, G.; Sornig, M.; Kroetz, P.; Stupar, D.

    2007-09-01

    The THIS instrument (Tuneable Heterodyne Infrared Spectrometer) is a versatile heterodyne receiver with a sensitivity close to theoretical prediction. It uses a Quantum Cascade Laser (QCL) as local oscillator and a HgCdTe photo-voltaic detector as mixer. The IF-spectrum is analyzed by means of a new broadband Acousto-Optical Spectrometer (AOS) with 3 GHz bandwidth and 1 MHz resolution. A dual sideband (DSB) system noise temperature has been measured with 2300 K at 10 μm wavelength, which is only 60% above the quantum limit. The stability of the system has been determined at an Allan variance minimum time of 50 seconds. Below this integration time the performance is purely radiometric. Also, the frequency stability has been measured with 1 MHz rms error within several hours. The quality of the instrument has been demonstrated by a few observing campaigns at the McMath-Pierce observatory on Kitt Peak. Measurements of Winds on Mars and Venus have been carried out and molecular line signals in sunspots have been detected. We propose to develop THIS as a second generation instrument for future astronomical observations on SOFIA.

  3. Exploration of the Saturn System by the Cassini Mission: Observations with the Cassini Infrared Spectrometer

    Science.gov (United States)

    Abbas, Mian M.

    2014-01-01

    The Cassini mission is a joint NASA-ESA international mission, launched on October 17, 1997 with 12 instruments on board, for exploration of the Saturn system. A composite Infrared Spectrometers is one of the major instruments. Successful insertion of the spacecraft in Saturn's orbit for an extended orbital tour occurred on July 1, 2004. The French Huygens-Probe on board, with six instruments was programmed for a soft landing on Titan's surface occurred in January 2005. The broad range scientific objectives of the mission are: Exploration of the Saturn system for investigations of the origin, formation, & evolution of the solar system, with an extensive range of measurements and the analysis of the data for scientific interpretations. The focus of research dealing with the Cassini mission at NASA/MSFC in collaboration with the NASA/Goddard Space Flight Center, JPL, as well as the research teams at Oxford/UK and Meudon Observatory/France, involves the Infrared observations of Saturn and its satellites, for measurements of the thermal structure and global distributions of the atmospheric constituents. A brief description of the Cassini spacecraft, the instruments, the objectives, in particular with the infrared observations of the Saturn system will be given. The analytical techniques for infrared radiative transfer and spectral inversion programs, with some selected results for gas constituent distributions will be presented.

  4. NIRS3: The Near Infrared Spectrometer on Hayabusa2

    Science.gov (United States)

    Iwata, Takahiro; Kitazato, Kohei; Abe, Masanao; Ohtake, Makiko; Arai, Takehiko; Arai, Tomoko; Hirata, Naru; Hiroi, Takahiro; Honda, Chikatoshi; Imae, Naoya; Komatsu, Mutsumi; Matsunaga, Tsuneo; Matsuoka, Moe; Matsuura, Shuji; Nakamura, Tomoki; Nakato, Aiko; Nakauchi, Yusuke; Osawa, Takahito; Senshu, Hiroki; Takagi, Yasuhiko; Tsumura, Kohji; Takato, Naruhisa; Watanabe, Sei-ichiro; Barucci, Maria Antonietta; Palomba, Ernesto; Ozaki, Masanobu

    2017-03-01

    NIRS3: The Near Infrared Spectrometer is installed on the Hayabusa2 spacecraft to observe the target C-type asteroid 162173 Ryugu at near infrared wavelengths of 1.8 to 3.2 μm. It aims to obtain reflectance spectra in order to detect absorption bands of hydrated and hydroxide minerals in the 3 μm-band. We adopted a linear-image sensor with indium arsenide (InAs) photo diodes and a cooling system with a passive radiator to achieve an optics temperature of 188 K ( -85°C), which enables to retaining sufficient sensitivity and noise level in the 3 μm wavelength region. We conducted ground performance tests for the NIRS3 flight model (FM) to confirm its baseline specifications. The results imply that the properties such as the signal-to-noise ratio (SNR) conform to scientific requirements to determine the degree of aqueous alteration, such as CM or CI chondrite, and the stage of thermal metamorphism on the asteroid surface.

  5. NIRS3: The Near Infrared Spectrometer on Hayabusa2

    Science.gov (United States)

    Iwata, Takahiro; Kitazato, Kohei; Abe, Masanao; Ohtake, Makiko; Arai, Takehiko; Arai, Tomoko; Hirata, Naru; Hiroi, Takahiro; Honda, Chikatoshi; Imae, Naoya; Komatsu, Mutsumi; Matsunaga, Tsuneo; Matsuoka, Moe; Matsuura, Shuji; Nakamura, Tomoki; Nakato, Aiko; Nakauchi, Yusuke; Osawa, Takahito; Senshu, Hiroki; Takagi, Yasuhiko; Tsumura, Kohji; Takato, Naruhisa; Watanabe, Sei-ichiro; Barucci, Maria Antonietta; Palomba, Ernesto; Ozaki, Masanobu

    2017-07-01

    NIRS3: The Near Infrared Spectrometer is installed on the Hayabusa2 spacecraft to observe the target C-type asteroid 162173 Ryugu at near infrared wavelengths of 1.8 to 3.2 μm. It aims to obtain reflectance spectra in order to detect absorption bands of hydrated and hydroxide minerals in the 3 μm-band. We adopted a linear-image sensor with indium arsenide (InAs) photo diodes and a cooling system with a passive radiator to achieve an optics temperature of 188 K (-85°C), which enables to retaining sufficient sensitivity and noise level in the 3 μm wavelength region. We conducted ground performance tests for the NIRS3 flight model (FM) to confirm its baseline specifications. The results imply that the properties such as the signal-to-noise ratio (SNR) conform to scientific requirements to determine the degree of aqueous alteration, such as CM or CI chondrite, and the stage of thermal metamorphism on the asteroid surface.

  6. Development of Real-Time Image Stabilization and Control Systems for an Airborne Infrared Spectrometer

    OpenAIRE

    2016-01-01

    The total solar eclipse of August 21, 2017 offers a unique opportunity for study of the infrared solar corona. The Airborne Infrared Spectrometer (AIR-Spec), currently under development, is an infrared telescope and spectrometer that will search for several magnetically sensitive coronal emission lines between 1.4 and 4 micrometers.  This instrument will be the first to observe several of these lines, and the measurement campaign will determine whether any lines may be useful for future direc...

  7. SW-MW infrared spectrometer for lunar mission

    Science.gov (United States)

    Banerjee, Arup; Biswas, Amiya; Joshi, Shaunak; Kumar, Ankush; Rehman, Sami; Sharma, Satish; Somani, Sandip; Bhati, Sunil; Karelia, Jitendra; Saxena, Anish; Chowdhury, Arup R.

    2016-04-01

    SW-MW Imaging Infrared Spectrometer, the Hyperspectral optical imaging instrument is envisaged to map geomorphology and mineralogy of lunar surface. The instrument is designed to image the electro-magnetic energy emanating from moon's surface with high spectral and spatial resolution for the mission duration from an altitude of 100 km. It is designed to cover 0.8 to 5 μm in 250 spectral bands with GSD 80m and swath 20km. Primarily, there are three basic optical segments in the spectrometer. They are fore optics, dispersing element and focusing elements. The payload is designed around a custom developed multi-blaze convex grating optimized for system throughput. The considerations for optimization are lunar radiation, instrument background, optical throughput, and detector sensitivity. HgCdTe (cooled using a rotary stirling cooler) based detector array (500x256 elements, 30μm) is being custom developed for the spectrometer. Stray light background flux is minimized using a multi-band filter cooled to cryogenic temperature. Mechanical system realization is being performed considering requirements such as structural, opto-mechanical, thermal, and alignment. The entire EOM is planned to be maintained at 240K to reduce and control instrument background. Al based mirror, grating, and EOM housing is being developed to maintain structural requirements along with opto- mechanical and thermal. Multi-tier radiative isolation and multi-stage radiative cooling approach is selected for maintaining the EOM temperature. EOM along with precision electronics packages are planned to be placed on the outer and inner side of Anti-sun side (ASS) deck. Power and Cooler drive electronics packages are planned to be placed on bottom side of ASS panel. Cooler drive electronics is being custom developed to maintain the detector temperature within 100mK during the imaging phase. Low noise detector electronics development is critical for maintaining the NETD requirements at different target

  8. Silicates on Iapetus from Cassini's Composite Infrared Spectrometer

    CERN Document Server

    Young, Cindy L; Clark, Roger N; Spencer, John R; Jennings, Donald E; Hand, Kevin P; Poston, Michael J; Carlson, Robert W

    2015-01-01

    We present the first spectral features obtained from Cassini's Composite Infrared Spectrometer (CIRS) for any icy moon. The spectral region covered by CIRS focal planes (FP) 3 and 4 is rich in emissivity features, but previous studies at these wavelengths have been limited by low signal to noise ratios (S/Rs) for individual spectra. Our approach is to average CIRS FP3 spectra to increase the S/R and use emissivity spectra to constrain the composition of the dark material on Iapetus. We find an emissivity feature at ~855 cm-1 and a possible doublet at 660 and 690 cm-1 that do not correspond to any known instrument artifacts. We attribute the 855 cm-1 feature to fine-grained silicates, similar to those found in dust on Mars and in meteorites, which are nearly featureless at shorter wavelengths. Silicates on the dark terrains of Saturn's icy moons have been suspected for decades, but there have been no definitive detections until now. Serpentines reported in the literature at ambient temperature and pressure hav...

  9. Mako airborne thermal infrared imaging spectrometer: performance update

    Science.gov (United States)

    Hall, Jeffrey L.; Boucher, Richard H.; Buckland, Kerry N.; Gutierrez, David J.; Keim, Eric R.; Tratt, David M.; Warren, David W.

    2016-09-01

    The Aerospace Corporation's sensitive Mako thermal infrared imaging spectrometer, which operates between 7.6 and 13.2 microns at a spectral sampling of 44 nm, and flies in a DeHavilland DHC-6 Twin Otter, has undergone significant changes over the past year that have greatly increased its performance. A comprehensive overhaul of its electronics has enabled frame rates up to 3255 Hz and noise reductions bringing it close to background-limited. A replacement diffraction grating whose peak efficiency was tuned to shorter wavelength, coupled with new AR coatings on certain key optics, has improved the performance at the short wavelength end by a factor of 3, resulting in better sensitivity for methane detection, for example. The faster frame rate has expanded the variety of different scan schemes that are possible, including multi-look scans in which even sizeable target areas can be scanned multiple times during a single overpass. Off-nadir scanning to +/-56.4° degrees has also been demonstrated, providing an area scan rate of 33 km2/minute for a 2-meter ground sampling distance (GSD) at nadir. The sensor achieves a Noise Equivalent Spectral Radiance (NESR) of better than 0.6 microflicks (μf, 10-6 W/sr/cm2/μm) in each of the 128 spectral channels for a typical airborne dataset in which 4 frames are co-added. An additional improvement is the integration of a new commercial 3D stabilization mount which is significantly better at compensating for aircraft motions and thereby maintains scan performance under quite turbulent flying conditions. The new sensor performance and capabilities are illustrated.

  10. SILICATES ON IAPETUS FROM CASSINI’S COMPOSITE INFRARED SPECTROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Young, Cindy L.; Wray, James J. [School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA (United States); Clark, Roger N. [Planetary Science Institute, Tucson, AZ (United States); Spencer, John R. [Southwest Research Institute, Boulder, CO (United States); Jennings, Donald E. [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Hand, Kevin P.; Carlson, Robert W. [Jet Propulsion Laboratory, Pasadena, CA (United States); Poston, Michael J. [Caltech, Pasadena, CA (United States)

    2015-10-01

    We present the first spectral features obtained from Cassini’s Composite Infrared Spectrometer (CIRS) for any icy moon. The spectral region covered by CIRS focal planes (FP) 3 and 4 is rich in emissivity features, but previous studies at these wavelengths have been limited by low signal-to-noise ratios (S/Ns) for individual spectra. Our approach is to average CIRS FP3 spectra to increase the S/N and use emissivity spectra to constrain the composition of the dark material on Iapetus. We find an emissivity feature at ∼855 cm{sup −1} and a possible doublet at 660 and 690 cm{sup −1} that do not correspond to any known instrument artifacts. We attribute the 855 cm{sup −1} feature to fine-grained silicates, similar to those found in dust on Mars and in meteorites, which are nearly featureless at shorter wavelengths. Silicates on the dark terrains of Saturn’s icy moons have been suspected for decades, but there have been no definitive detections until now. Serpentines reported in the literature at ambient temperature and pressure have features near 855 and 660 cm{sup −1}. However, peaks can shift depending on temperature and pressure, so measurements at Iapetus-like conditions are necessary for more positive feature identifications. As a first investigation, we measured muscovite at 125 K in a vacuum and found that this spectrum does match the emissivity feature near 855 cm{sup −1} and the location of the doublet. Further measurements are needed to robustly identify a specific silicate, which would provide clues regarding the origin and implications of the dark material.

  11. Validation of MOPITT carbon monoxide using ground-based Fourier transform infrared spectrometer data from NDACC

    Science.gov (United States)

    Buchholz, Rebecca R.; Deeter, Merritt N.; Worden, Helen M.; Gille, John; Edwards, David P.; Hannigan, James W.; Jones, Nicholas B.; Paton-Walsh, Clare; Griffith, David W. T.; Smale, Dan; Robinson, John; Strong, Kimberly; Conway, Stephanie; Sussmann, Ralf; Hase, Frank; Blumenstock, Thomas; Mahieu, Emmanuel; Langerock, Bavo

    2017-06-01

    The Measurements of Pollution in the Troposphere (MOPITT) satellite instrument provides the longest continuous dataset of carbon monoxide (CO) from space. We perform the first validation of MOPITT version 6 retrievals using total column CO measurements from ground-based remote-sensing Fourier transform infrared spectrometers (FTSs). Validation uses data recorded at 14 stations, that span a wide range of latitudes (80° N to 78° S), in the Network for the Detection of Atmospheric Composition Change (NDACC). MOPITT measurements are spatially co-located with each station, and different vertical sensitivities between instruments are accounted for by using MOPITT averaging kernels (AKs). All three MOPITT retrieval types are analyzed: thermal infrared (TIR-only), joint thermal and near infrared (TIR-NIR), and near infrared (NIR-only). Generally, MOPITT measurements overestimate CO relative to FTS measurements, but the bias is typically less than 10 %. Mean bias is 2.4 % for TIR-only, 5.1 % for TIR-NIR, and 6.5 % for NIR-only. The TIR-NIR and NIR-only products consistently produce a larger bias and lower correlation than the TIR-only. Validation performance of MOPITT for TIR-only and TIR-NIR retrievals over land or water scenes is equivalent. The four MOPITT detector element pixels are validated separately to account for their different uncertainty characteristics. Pixel 1 produces the highest standard deviation and lowest correlation for all three MOPITT products. However, for TIR-only and TIR-NIR, the error-weighted average that includes all four pixels often provides the best correlation, indicating compensating pixel biases and well-captured error characteristics. We find that MOPITT bias does not depend on latitude but rather is influenced by the proximity to rapidly changing atmospheric CO. MOPITT bias drift has been bound geographically to within ±0.5 % yr-1 or lower at almost all locations.

  12. Infrared fiber coupled acousto-optic tunable filter spectrometer

    Science.gov (United States)

    Levin, K. H.; Kindler, E.; Ko, T.; Lee, F.; Tran, D. C.; Tapphorn, R. M.

    A spectrometer design is introduced which combines an acoustooptic tunable filter (AOTF) and IR-transmitting flouride-glass fibers. The AOTF crystal is fabricated from TeO2 and permits random access to any wavelength in less than 50 microseconds, and the resulting spectrometer is tested for the remote analysis of gases and hydrocarbons. The AOTF spectrometer, when operated with a high-speed frequency synthesizer and optimized algorithms, permits accurate high-speed spectroscopy in the mid-IR spectral region.

  13. Magnetic suspension based Fourier Transform Infrared Spectrometer mechanism (FTIS)

    Science.gov (United States)

    Köker, Ingo; Langenbach, Harald; Schmid, Manfred; Lautier, Jean-Michel

    2005-07-01

    In the frame of an ESTEC technology contract the development of a Magnetically Suspended Fourier Transform Spectrometer Mechanism (FTIS) was carried out. The aim of the development is to avoid the issues found in mechanically suspended systems and to provide an active alignment and disturbance rejection capability for spectrometer applications. In the frame of FTIS an actively controlled suspension system based on the use of magnetic bearings was defined, developed and built as a demonstration model.

  14. Development of a near-infrared/mid-infrared dual-region spectrometer for online process analysis.

    Science.gov (United States)

    Genkawa, Takuma; Watari, Masahiro; Nishii, Takashi; Ozaki, Yukihiro

    2012-07-01

    A near-infrared (NIR) and mid-infrared (mid-IR) dual-region spectrometer having two immersion probes, a transmission probe for NIR, and an attenuated total reflection (ATR) probe for mid-IR has been developed for highly reliable process monitoring and deep process understanding. This spectrometer facilitates sequential acquisition of both NIR (10,000-4000 cm(-1)) and mid-IR (5000-1200 cm(-1)) spectra by switching the light path leading to the probes without the need for probe replacement. The use of a single light source and a single beam splitter enables achievement of a permanent alignment of the optical system and sequential data acquisition. The transmission NIR and ATR mid-IR probes designed and developed in the present study facilitate the acquisition of NIR/mid-IR spectra with optimized absorption intensities in both regions by simply placing the probes into a sample solution. The performance of the developed spectrometer was demonstrated in monitoring the ethanol fermentation process. NIR/mid-IR spectra of the fermentation solution with multiplicative scatter correction (MSC) represent the relative changes in the concentrations of glucose and ethanol in both regions. Principal component analysis (PCA) was performed on the MSC-treated spectra in the regions 6300-5650 cm(-1), 4850-4300 cm(-1), and 3500-2880 cm(-1) to detect the end-point of the fermentation as an example of process monitoring. For all the regions, the score plot of the first principal component (PC) indicates that the fermentation progresses with the fermentation time and stops after 210 minutes and thus the end-point of the fermentation exists at around 210 minutes. The loading plot indicates that all of the first PCs are the relative changes in the concentrations of glucose and ethanol. This result reveals that the same chemical changes are observed in both transmission NIR and ATR mid-IR spectra. Multiple and simultaneous analysis was also performed, and intensity change in light

  15. The (new) Mid-Infrared Spectrometer and Imager (MIRSI) for the NASA Infrared Telescope Facility

    Science.gov (United States)

    Hora, Joseph L.; Trilling, David; Mommert, Michael; Smith, Howard A.; Moskovitz, Nicholas; Marscher, Alan P.; Tokunaga, Alan; Bergknut, Lars; Bonnet, Morgan; Bus, Schelte J.; Connelly, Michael; Rayner, John; Watanabe, Darryl

    2015-11-01

    The Mid-Infrared Spectrometer and Imager (MIRSI) was developed at Boston University and has been in use since 2002 on the Infrared Telescope Facility (IRTF), making observations of asteroids, planets, and comets in the 2 - 25 μm wavelength range. Recently the instrument has been unavailable due to electronics issues and the high cost of supplying liquid helium on Maunakea. We have begun a project to upgrade MIRSI to a cryocooler-based system with new array readout electronics and a dichroic and optical camera to simultaneously image the science field for image acquisition and optical photometry. The mechanical cryocooler will enable MIRSI to be continuously mounted on the IRTF multiple instrument mount (MIM) along with the other facility instruments, making it available to the entire community for multi-wavelength imaging and spectral observations. We will propose to use the refurbished MIRSI to measure the 10 μm flux from Near Earth Objects (NEOs) and determine their diameters and albedos through the use of a thermal model. We plan to observe up to 750 NEOs over the course of a three year survey, most of whose diameters will be under 300 meters. Here we present an overview of the MIRSI upgrade and give the current status of the project.This work is funded by the NASA Solar System Observations/NEOO program.

  16. Dualband infrared imaging spectrometer: observations of the moon

    Science.gov (United States)

    LeVan, Paul D.; Beecken, Brian P.; Lindh, Cory

    2008-08-01

    We reported previously on full-disk observations of the sun through a layer of black polymer, used to protect the entrance aperture of a novel dualband spectrometer while transmitting discrete wavelength regions in the MWIR & LWIR1. More recently, the spectrometer was used to assess the accuracy of recovery of unknown blackbody temperatures2. Here, we briefly describe MWIR observations of the full Moon made in Jan 2008. As was the case for the solar observations, the Moon was allowed to drift across the spectrometer slit by Earth's rotation. A detailed sensor calibration performed prior to the observations accounts for sensor non-uniformities; the spectral images of the Moon therefore include atmospheric transmission features. Our plans are to repeat the observations at liquid helium temperatures, thereby allowing both MWIR & LWIR spectral coverage.

  17. Infrared Spectral Radiance Intercomparisons With Satellite and Aircraft Sensors

    Science.gov (United States)

    Larar, Allen M.; Zhou, Daniel K.; Liu, Xu; Smith, William L.

    2014-01-01

    Measurement system validation is critical for advanced satellite sounders to reach their full potential of improving observations of the Earth's atmosphere, clouds, and surface for enabling enhancements in weather prediction, climate monitoring capability, and environmental change detection. Experimental field campaigns, focusing on satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft, are an essential part of the validation task. Airborne FTS systems can enable an independent, SI-traceable measurement system validation by directly measuring the same level-1 parameters spatially and temporally coincident with the satellite sensor of interest. Continuation of aircraft under-flights for multiple satellites during multiple field campaigns enables long-term monitoring of system performance and inter-satellite cross-validation. The NASA / NPOESS Airborne Sounder Testbed - Interferometer (NAST-I) has been a significant contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This presentation gives an overview of benefits achieved using airborne sensors such as NAST-I utilizing examples from recent field campaigns. The methodology implemented is not only beneficial to new sensors such as the Cross-track Infrared Sounder (CrIS) flying aboard the Suomi NPP and future JPSS satellites but also of significant benefit to sensors of longer flight heritage such as the Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) on the AQUA and METOP-A platforms, respectively, to ensure data quality continuity important for climate and other applications. Infrared spectral radiance inter-comparisons are discussed with a particular focus on usage of NAST-I data for enabling inter-platform cross-validation.

  18. An optically detected magnetic resonance spectrometer with tunable laser excitation and wavelength resolved infrared detection

    CERN Document Server

    Negyedi, M; Gyüre, B; Dzsaber, S; Kollarics, S; Rohringer, P; Pichler, T; Simon, F

    2016-01-01

    We present the development and performance of an optically detected magnetic resonance (ODMR) spectrometer. The spectrometer represents advances over similar instruments in three areas: i) the exciting light is a tunable laser source which covers much of the visible light range, ii) the optical signal is analyzed with a spectrograph, iii) the emitted light is detected in the near-infrared domain. The need to perform ODMR experiments on single-walled carbon nanotubes motivated the present development and we demonstrate the utility of the spectrometer on this material. The performance of the spectrometer is critically compared to similar instruments. The present development opens the way to perform ODMR studies on various new materials such as molecules and luminescent quantum dots where the emission is in the near-infrared range and requires a well-defined excitation wavelength and analysis of the scattered light.

  19. A graphene-based Fabry-Pérot spectrometer in mid-infrared region

    Science.gov (United States)

    Wang, Xiaosai; Chen, Chen; Pan, Liang; Wang, Jicheng

    2016-08-01

    Mid-infrared spectroscopy is of great importance in many areas and its integration with thin-film technology can economically enrich the functionalities of many existing devices. In this paper we propose a graphene-based ultra-compact spectrometer (several micrometers in size) that is compatible with complementary metal-oxide-semiconductor (CMOS) processing. The proposed structure uses a monolayer graphene as a mid-infrared surface waveguide, whose optical response is spatially modulated using electric fields to form a Fabry-Pérot cavity. By varying the voltage acting on the cavity, we can control the transmitted wavelength of the spectrometer at room temperature. This design has potential applications in the graphene-silicon-based optoelectronic devices as it offers new possibilities for developing new ultra-compact spectrometers and low-cost hyperspectral imaging sensors in mid-infrared region.

  20. A Novel Miniaturised Infrared Imaging Spectrometer for the Measurement of Atmospheric Trace Gases

    Science.gov (United States)

    Mortimer, A. H.

    2012-04-01

    A novel, ultra-compact Static Imaging Fourier Transform Spectrometer, SIFTS, with no moving parts has been developed for the remote and in-situ detection of atmospheric gases. This technique has previously been demonstrated in the visible spectral region (400 to 1100nm) using a CCD detector. This paper the author presents the results of the infrared version of the SIFTS instrument, which uses an uncooled microbolometer detector array to measure infrared spectra (7 to 14μm) with a resolution of up 4 cm-1 and temporal resolution of 30Hz. The technique is based on a static optical configuration whereby light is split into two paths and made to recombine along a focal plane producing an interference pattern. The spectral information is returned using a detector array to digitally capture the interferogram which can then be processed into a spectrum by the application of a Fourier transform. The novel optical design has reduced the optics required to only 3 optical components and the detector array, to generate and measure the interferogram. The experimental performance of the SIFTS instrument has verified the theoretical models, which has shown that the spectral resolution is for the infrared instrument is 4cm-1. The Connes advantage, inherent to the Michelson spectrometer Fourier Transform Spectrometer (FTS), whereby the spectral wavelength accuracy is referenced to a stabilised laser has also been demonstrated in the SIFTS instrument. This has been implemented through the use of an expanded internal laser diode with Distributed Bragg Reflector (DFB) which acts as the calibration source used to maintain the wavelength stability of the SIFTS instrument. As there are no moving components, the instrument is compact, light and insensitive to mechanical vibration, additionally the speed of measurement is determined by the frame rate of the detector array. Thus, this instrument has a temporal advantage over common Michelson FTIR instruments. For example, this technique has

  1. Satellite observations of ethylene (C2H4) from the Aura Tropospheric Emission Spectrometer: A scoping study

    Science.gov (United States)

    Dolan, Wayana; Payne, Vivienne H.; Kualwik, Susan S.; Bowman, Kevin W.

    2016-09-01

    We present a study focusing on detection and initial quantitative estimates of ethylene (C2H4) in observations from the Tropospheric Emission Spectrometer (TES), a Fourier transform spectrometer aboard the Aura satellite that measures thermal infrared radiances with high spectral resolution (0.1 cm-1). We analyze observations taken in support of the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission and demonstrate the feasibility of future development of C2H4 into a TES standard product. In the Northern Hemisphere, C2H4 is commonly associated with boreal fire plumes, motor vehicle exhaust and petrochemical emissions. It has a short lifetime (∼14-32 h) in the troposphere due to its reaction with OH and O3. Chemical destruction of C2H4 in the atmosphere leads to the production of ozone and other species such as carbon monoxide (CO) and formaldehyde. Results indicate a correlation between C2H4 and CO in boreal fire plumes. Quantitative C2H4 estimates are sensitive to assumptions about the plume height and width. We find that C2H4 greater than 2-3 ppbv can be detected in a single TES observation (for a fire plume at 3 km altitude and 1.5 km width). Spatial averaging will be needed for surface-peaking profiles where TES sensitivity is lower.

  2. Low-Cost Satellite Infrared Imager Study

    Science.gov (United States)

    2007-11-02

    2,297.00 10 MATLAB , Simulink , Symbolic Math Toolbox (2 ea @ £894) £1,788.00 11 MATLAB Image Processing Toolbox (2 ea at £192) £384.00 12 MATLAB ...Figure 1: MWIR and TIR satellite imagery. On the left is a BIRD image of forest fires on the Portuguese/ Spanish border3 and the image on right is...space-borne MWIR and TIR imagers, instrument engineers are continually evaluating advances in the miniaturization of detector technology. One

  3. Development of the first infrared satellite observatory

    Science.gov (United States)

    Smith, G. M.; Squibb, G. F.

    1984-01-01

    A development history is given for the Infrared Astronomical Satelite (IRAS), whose primary mission objective is an unbiased, all-sky survey in the 8-120 micron wavelength range. A point source catalog of more than 200,000 IR sources, to be published later this year, represents the accomplishment of this objective. IRAS has also conducted 10,000 pointed observations of specific objects. Attention is given to the cost increases and schedule slips which resulted from the substantial technical challenges of IRAS hardware and software development, and to the management techniques which had to be employed in this major international project.

  4. Pocket-size near-infrared spectrometer for narcotic materials identification

    Science.gov (United States)

    Pederson, Christopher G.; Friedrich, Donald M.; Hsiung, Chang; von Gunten, Marc; O'Brien, Nada A.; Ramaker, Henk-Jan; van Sprang, Eric; Dreischor, Menno

    2014-05-01

    While significant progress has been made towards the miniaturization of Raman, mid-infrared (IR), and near-infrared (NIR) spectrometers for homeland security and law enforcement applications, there remains continued interest in pushing the technology envelope for smaller, lower cost, and easier to use analyzers. In this paper, we report on the use of the MicroNIR Spectrometer, an ultra-compact, handheld near infrared (NIR) spectrometer, the, that weighs less than 60 grams and measures heroin, oxycodone, diazepam), as well as synthetic cathinones (also known as bath salts), and synthetic cannabinoids. A library of the materials was created from a master MicroNIR spectrometer. A set of 25 unknown samples were then identified with three other MicroNIRs showing: 1) the ability to correctly identify the unknown with a very low rate of misidentification, and 2) the ability to use the same library with multiple instruments. In addition, we have shown that through the use of innovative chemometric algorithms, we were able to identify the individual compounds that make up an unknown mixture based on the spectral library of the individual compounds only. The small size of the spectrometer is enabled through the use of high-performance linear variable filter (LVF) technology.

  5. User Guide to the PDS Dataset for the Cassini Composite Infrared Spectrometer (CIRS)

    Science.gov (United States)

    Nixon, Conor A.; Kaelberer, Monte S.; Gorius, Nicolas

    2012-01-01

    This User Guide to the Cassini Composite Infrared Spectrometer (CIRS) has been written with two communities in mind. First and foremost, scientists external to the Cassini Project who seek to use the CIRS data as archived in the Planetary Data System (PDS). In addition, it is intended to be a comprehensive reference guide for those internal to the CIRS team.

  6. Postdispersion system for astronomical observations with Fourier transform spectrometers in the thermal infrared

    Science.gov (United States)

    Wiedermann, Guenter; Jennings, D. E.; Hanel, R. H.; Kunde, V. G.; Moseley, S. H.

    1989-01-01

    A postdispersion system for astronomical observations with Fourier transform spectrometers in the thermal infrared has been developed which improves the sensitivity of radiation noise limited observations by reducing the spectral range incident on the detector. Special attention is given to the first-generation blocked impurity band detector. Planetary, solar, and stellar observations are reported.

  7. Aircraft laser infrared absorption spectrometer (ALIAS) for polar ozone studies

    Science.gov (United States)

    Webster, C. R.; May, R. D.

    1991-01-01

    The ALIAS instrument is a very high resolution (0.0003/cm) scanning, tunable diode laser spectrometer designed to make direct, simultaneous measurements of NO2, HNO3, HCl, CH4, and either O3 or N2O (including vertical profiles of CH4 and N2O) in the polar stratosphere at sub-part-per-billion level sensitivities over integration times from 3 to 30 s. Unique features include a sample inlet/throttle system designed to achieve near-isokinetic sampling, in PSC events, an in-flight wavelength reference cell rack, mechanical fringe-spoilers, a four-laser/four-detector dewar with 24-hr hold-time operating at a fixed temperature without electrical regulation, and in-flight fast correlation routines for spectral drift compensation prior to spectral addition. Instrument design and test flight results are discussed in the light of ALIAS's role in the Winter 1991 Arctic aircraft stratospheric ozone campaigns out of Fairbanks, Alaska, and Bangor, Maine.

  8. [Design and implementation of a long wavelength near infrared spectrometer based on MEMS scanning mirror].

    Science.gov (United States)

    Ye, Kun-Tao; Dong, Tai-Yuan; He, Wen-Xi; Li, Yu-Xiao; Cheng, Xian-Ming; Li, Guang-Yong; Li, Hao-Yu; Xu, Hao-Yu

    2014-10-01

    Long Wavelength Near InfraRed (LW-NIR) spectrometer has wide applications. Miniaturization and low-cost are two major goals of the development of LW-NIR spectrometer in the industrial or research community. Under the background that having a trend of spectrometer miniaturization and integration, method and main problems involved in miniaturization of LW-NIR spectrometer through MEMS scanning mirror, such as the design strategy of the light-splitting optical system, selection considerations of the MEMS scanning mirror, design method of the preamplifier circuit, etc, have been presented in detail. A prototype of miniaturized LW-NIR spectrometer, with the spectrum range of detection of 900-2,055 nm, is designed and implemented using MEMS scanning mirror, InGaAs single detector unit with high sensitivity. Littrow optical layout is used for its light-splitting optical system, and the spectral resolution is between 9.4-16 nm at 1,000-1,965 nm detection wavelength range. The prototype is successfully applied in LW-NIR spectrum measurement on pure water and ethanol aqueous solution, and a forecast analysis on ethanol aqueous solution concentration is also demonstrated. Through adopting MEMS scanning mirror into the spectrometer system, the complexity of the mechanical scanning fixtures and its controlling mechanism is greatly reduced therefore the size of the spectrometer is reduced. Furthermore, due to MEMS scanning mirror technology, LW-NIR spectrometer with single InGaAs detector is achieved, thus the cost reduction of the NIR spectrometer system is also realized because the expensive InGaAs arrays are avoided.

  9. The Cosmic Infrared Background Experiment: Flight Characterization Of The Ciber Narrow Band Spectrometer.

    Science.gov (United States)

    Levenson, Louis R.; Battle, J.; Bock, J. J.; Cooray, A.; Hristov, V.; Keating, B.; Lee, D.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Suzuki, K.; Wada, T.; Zemcov, M.

    2011-01-01

    Subtraction of the Zodiacal light foreground is the dominant source of uncertainty in absolute photometric measurements of the extra-galactic background at near-infrared to optical wavelengths. The second flight of the Cosmic Infrared Background ExpeRiment (CIBER) occurred on July 10th, 2010. CIBER is a NASA sounding rocket experiment carrying four co-aligned instruments including two imaging telescopes with wide passbands centered at 1 and 1.6 microns, respectively, as well as a low resolution spectrometer and a narrow-band spectrometer. THE CIBER spectrometers are absolutely calibrated in collaboration with NIST. The narrow-band spectrometer filter is centered on the Ca II solar Fraunhofer line at 854.2 nm and is designed to measure the equivalent width of the solar line reflected by the interplanetary dust in order to obtain an absolute measurement of the Zodiacal contribution to the infrared sky at that wavelength. In conjunction with measured low resolution spectrum from 700 to 1900 nm, this will provide an accurate independent check of the DIRBE Zodiacal light models. Here we describe the NBS instrument, calibration and in-flight characterization.

  10. Widely tunable rapid-scanning mid-infrared laser spectrometer for industrial gas process stream analysis.

    Science.gov (United States)

    Bamford, Douglas J; Cook, David J; Sharpe, Scott J; Van Pelt, Aaron D

    2007-07-01

    A mid-infrared spectrometer with a tuning range of >400 cm(-1) in the C-H stretching region of the spectrum has been designed and constructed. The spectrometer is based on the difference-frequency generation of two tunable diode lasers in periodically poled lithium niobate waveguides. Tuning is achieved by varying a single parameter, the wavelength of one of the near-infrared input lasers. The instrument can be tuned over the entire tuning range in less than 1 s. By taking advantage of the wide tuning range, the instrument has been used to analyze a mixture of methane, ethylene, and propylene. Each of these major components was measured with an accuracy of better than 2% (where the error is defined as a percentage of the measured value) in a single 30 s long scan. When optimized, the spectrometer has the potential to meet both the performance requirements and the practical requirements for real-time process control in petrochemical manufacturing. The general principles for the design of mid-infrared spectrometers with wide tuning ranges are explained, including the use of variable waveguide fabrication recipes to create broad phase-matching resonances (which lead to broad tuning) in the desired location.

  11. Spacecraft design project: High temperature superconducting infrared imaging satellite

    Science.gov (United States)

    1991-01-01

    The High Temperature Superconductor Infrared Imaging Satellite (HTSCIRIS) is designed to perform the space based infrared imaging and surveillance mission. The design of the satellite follows the black box approach. The payload is a stand alone unit, with the spacecraft bus designed to meet the requirements of the payload as listed in the statement of work. Specifications influencing the design of the spacecraft bus were originated by the Naval Research Lab. A description of the following systems is included: spacecraft configuration, orbital dynamics, radio frequency communication subsystem, electrical power system, propulsion, attitude control system, thermal control, and structural design. The issues of testing and cost analysis are also addressed. This design project was part of the course Advanced Spacecraft Design taught at the Naval Postgraduate School.

  12. Ims: The Infrared Mapping Spectrometer of The Bepicolombo Mission

    Science.gov (United States)

    Erard, S.

    The IR Spectrometer on board BepiColomboSs Planetary Orbiter aims at investigating the 0.8-2.8 micron range, where the absorption bands of major rock-forming miner- als are found. Spatial resolution values on the order of 100 m are needed for regolith mixing studies (~200U300 m mixing scale), while moderate spectral resolution only is required (~20-40 nm spectral sampling). Requirement for signal to noise ratio is * 100 in the whole spectral range. The baseline for the model payload is presented here. The optical system has a FOV of 256 mrad, and a focal length of 32 mm. The dis- persion system is a grating, feeding the radiation onto a 512x512 array. Line binning is performed by 4 in the spectral dimension to obtain 128 channels, with resulting IFOV of 0.5 mrad. The instrument works in pushbroom mode, with spectral disper- sion along the lines of the matrix, and spatial information along the other direction. A cryo-interface has to be provided to cool down the detector in the U153/-73C range. A complete low-resolution coverage of the planet is performed in 6 months, and repre- sents 30 Gbits with a data compression rate of 8 (lossy). A similar data rate is reserved for high-resolution observations from pericenter, so that the overall continuous trans- fer rate ranges from 4 to 12 kb/s, depending on compression rate. The main critical issues currently have to do with thermal control and marginally with data rates. A pos- sible approach is to set a cut-off at 2.8 micron to reduce the thermal load down to~0.29 W (external heat load on aperture). Filtering the visible range could also help reduce the thermal load on the detector by another factor of 2.

  13. Performance of the Imaging Fourier Transform Spectrometer with Photoconductive Detector Arrays: An Application for the AKARI Far-Infrared Instrument

    CERN Document Server

    Kawada, Mitsunobu; Murakami, Noriko; Matsuo, Hiroshi; Okada, Yoko; Yasuda, Akiko; Matsuura, Shuji; Shirahata, Mai; Doi, Yasuo; Kaneda, Hidehiro; Ootsubo, Takafumi; Nakagawa, Takao; Shibai, Hiroshi

    2008-01-01

    We have developed an imaging Fourier transform spectrometer (FTS) for space-based far-infrared astronomical observations. The FTS employs a newly developed photoconductive detector arrays with a capacitive trans-impedance amplifier, which makes the FTS a completely unique instrument. The FTS was installed as a function of the far-infrared instrument (FIS: Far-Infrared Surveyor) on the Japanese astronomical satellite, AKARI, which was launched on February 21, 2006 (UT) from the Uchinoura Space Center. The FIS-FTS had been operated for more than one year before liquid helium ran out on August 26, 2007. The FIS-FTS was operated nearly six hundreds times, which corresponds to more than one hundred hours of astronomical observations and almost the same amount of time for calibrations. As expected from laboratory measurements, the FIS-FTS performed well and has produced a large set of astronomical data for valuable objects. Meanwhile, it becomes clear that the detector transient effect is a considerable factor for ...

  14. Detection of fatty product falsifications using a portable near infrared spectrometer

    Science.gov (United States)

    Kalinin, A. V.; Krasheninnikov, V. N.

    2016-12-01

    Spreading sales of counterfeited fatty-oil foods leads to a development of portable and operational analyzer of typical fatty acids (FA) which may be a near infrared (NIR) spectrometer. In this work the calibration models for prediction of named FA were built with the spectra of FT-NIR spectrometer for different absorption bands of the FA. The best parameters were obtained for the wavelength sub-band 1.0-1.8 μ, which includes the 2nd and 3rd overtones of C-H stretching vibrations (near 1.7 and 1.2 μ) and the combination band (1.42 μ). Applicability of the portable spectrometer based on linear NIR array photosensor for the quality analysis of spread, butter and fish oil by the typical FA has been tested.

  15. Detection of fatty product falsifications using a portable near infrared spectrometer

    Science.gov (United States)

    Kalinin, A. V.; Krasheninnikov, V. N.

    2017-01-01

    Spreading sales of counterfeited fatty-oil foods leads to a development of portable and operational analyzer of typical fatty acids (FA) which may be a near infrared (NIR) spectrometer. In this work the calibration models for prediction of named FA were built with the spectra of FT-NIR spectrometer for different absorption bands of the FA. The best parameters were obtained for the wavelength sub-band 1.0-1.8 μ, which includes the 2nd and 3rd overtones of C-H stretching vibrations (near 1.7 and 1.2 μ) and the combination band (1.42 μ). Applicability of the portable spectrometer based on linear NIR array photosensor for the quality analysis of spread, butter and fish oil by the typical FA has been tested.

  16. THIS -- next-generation mid-infrared remote sensing of planetary atmospheres using a tuneable heterodyne infrared spectrometer

    Science.gov (United States)

    Sonnabend, G.; Wirtz, D.; Vetterle, V.; Schieder, R.

    2003-12-01

    The Cologne spectrometer THIS (Tuneable Heterodyne Infrared Spectrometer) opens the mid-infrared wavelength region from 8 to 17 microns to ultra-high-resolution spectroscopy. The main scientific goal of THIS is to analyze highly resolved lineshape data of molecules (e.g. O3, NH3, CH4, N2O, HxCy etc.) to deduce physical parameters like wind velocities or height profiles of gases in either the Earth's or other planetary atmospheres. Also astronomical observations of non-solar-system IR-sources like IRC+10216 as well as the measurement of pure rotational transitions of H2 in the interstellar-medium from ground based telescopes are planned in the near future. THIS is a proposed second-generation instrument for the stratospheric observatory SOFIA. With a system noise temperature of less than three times the quantum limit THIS is the first widely tuneable and transportable infrared heterodyne receiver having a sensitivity equivalent to CO2-laser based heterodyne systems. A quantum-cascade-laser is used as local oscillator. Its radiation is superimposed to that from the signal by use of a Fabry-Perot ring-resonator to provide optimum efficiency. The frequency mixing is done by a Mercury-Cadmium-Telluride photomixer and spectral analysis with a resolution of up to 3x107 is performed by means of an Acousto-Optical spectrometer. We report on THIS' successful first observing run performed at the west auxiliary telescope at McMath-Pierce solar observatory on Kitt Peak/Arizona in 11/2002. Very weak non-LTE CO2 emission from the atmosphere of Venus have been observed as well as trace gases in Earth's atmosphere and molecular features in sunspots.

  17. Authentication of Whey Protein Powders by Portable Mid-Infrared Spectrometers Combined with Pattern Recognition Analysis.

    Science.gov (United States)

    Wang, Ting; Tan, Siow Ying; Mutilangi, William; Aykas, Didem P; Rodriguez-Saona, Luis E

    2015-10-01

    The objective of this study was to develop a simple and rapid method to differentiate whey protein types (WPC, WPI, and WPH) used for beverage manufacturing by combining the spectral signature collected from portable mid-infrared spectrometers and pattern recognition analysis. Whey protein powders from different suppliers are produced using a large number of processing and compositional variables, resulting in variation in composition, concentration, protein structure, and thus functionality. Whey protein powders including whey protein isolates, whey protein concentrates and whey protein hydrolysates were obtained from different suppliers and their spectra collected using portable mid-infrared spectrometers (single and triple reflection) by pressing the powder onto an Attenuated Total Reflectance (ATR) diamond crystal with a pressure clamp. Spectra were analyzed by soft independent modeling of class analogy (SIMCA) generating a classification model showing the ability to differentiate whey protein types by forming tight clusters with interclass distance values of >3, considered to be significantly different from each other. The major bands centered at 1640 and 1580 cm(-1) were responsible for separation and were associated with differences in amide I and amide II vibrations of proteins, respectively. Another important band in whey protein clustering was associated with carboxylate vibrations of acidic amino acids (∼1570 cm(-1)). The use of a portable mid-IR spectrometer combined with pattern recognition analysis showed potential for discriminating whey protein ingredients that can help to streamline the analytical procedure so that it is more applicable for field-based screening of ingredients. A rapid, simple and accurate method was developed to authenticate commercial whey protein products by using portable mid-infrared spectrometers combined with chemometrics, which could help ensure the functionality of whey protein ingredients in food applications. © 2015

  18. Mission design for the infrared astronomical satellite /IRAS/

    Science.gov (United States)

    Lundy, S. A.; Mclaughlin, W. I.; Pouw, A.

    1979-01-01

    IRAS, a joint United States, Netherlands, United Kingdom astronomical satellite, is scheduled to be launched early in 1981 with the purpose of completing an all-sky survey in the infrared wavelengths from 8 to 120 microns and to observe objects of special interest. The mission design is driven by thermal constraints primarily determined by the Sun and Earth; the orbit and survey strategy must be chosen so as to satisfy the mission requirements before the cryogenic system is depleted of its liquid helium. Computer graphics help the designer choose valid survey strategies and evaluate resulting sky coverage.

  19. The infrared astronomical satellite AKARI: overview, highlights of the mission

    Science.gov (United States)

    Murakami, Hiroshi; Matsuhara, Hideo

    2008-07-01

    The AKARI, Japanese infrared astronomical satellite, is a 68.5 cm cooled telescope with two focal-plane instruments providing continuous sky scan at six wavelength bands in mid- and far-infrared. The instruments also have capabilities of imaging and spectroscopy in the wavelength range 2-180 μm in the pointing observations occasionally inserted into the continuous survey. AKARI was launched on 21st Feb. 2006, and has performed the all-sky survey as well as 5380 pointing observations until the liquid helium exhaustion on 26th Aug. 2007. The all sky survey covers more than 90 percent of the entire sky with higher spatial resolutions and sensitivities than the IRAS. First version of the infrared source catalogue will be released in 2009. Here we report the overview of the mission, highlights on the scientific results as well as the performance of the focal-plane instruments. We also present the observation plan with the near infrared camera during the post-helium mission phase started in June 2008.

  20. SNR analysis and Hadamard mask modification of DMD Hadamard Transform Near-Infrared spectrometer

    Science.gov (United States)

    Xu, Jia-lin; Liu, Hua; Lin, Chun-bo; Sun, Qiang

    2017-01-01

    The noise of Hadamard Transform (HT) Near Infrared (NIR) spectrometer includes not only the detector circuit noise but also the illumination noise. Hadamard Transform reduces the detector noise while increases the illumination noise. If the relative power intensity is large, the noise of Hadamard method will be greater than that of scanning method. This will lose the significance of Hadamard Transform. In this paper the SNRs of the Hadamard method and scanning method are analyzed. The condition of boosting SNR of spectrometer by Hadamard transform is given. When the condition is not matched, a Hadamard mask of variable height stripes is proposed which the SNR of Hadamard method can be improved. In this paper a HT NIR spectrometer based on 0.45-inch DMD is designed with the spectrum range from 1350 nm to 2500 nm. Several experiments are done with the designed spectrometer. It is shown that with the Hadamard mask of variable height stripes the average SNR is improved by a factor of 2.2 at the short wavelength band and by a factor of 2.8 on the long wavelength band, and the minimum SNR on the whole wavelength band is improved by a factor of 2.3.

  1. The Cosmic Infrared Background Experiment (CIBER): The Narrow-Band Spectrometer

    Science.gov (United States)

    Korngut, P. M.; Renbarger, T.; Arai, T.; Battle, J.; Bock, J.; Brown, S. W.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lanz, A.; Lee, D. H.; Levenson, L. R.; Lykke, K. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Shultz, B.; Smith, A. W.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2013-08-01

    We have developed a near-infrared spectrometer designed to measure the absolute intensity of the solar 854.2 nm Ca II Fraunhofer line, scattered by interplanetary dust, in the zodiacal light (ZL) spectrum. Based on the known equivalent line width in the solar spectrum, this measurement can derive the zodiacal brightness, testing models of the ZL based on morphology that are used to determine the extragalactic background light in absolute photometry measurements. The spectrometer is based on a simple high-resolution tipped filter placed in front of a compact camera with wide-field refractive optics to provide the large optical throughput and high sensitivity required for rocket-borne observations. We discuss the instrument requirements for an accurate measurement of the absolute ZL brightness, the measured laboratory characterization, and the instrument performance in flight.

  2. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): THE NARROW-BAND SPECTROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Korngut, P. M.; Bock, J. [Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA), Pasadena, CA 91109 (United States); Renbarger, T.; Keating, B. [Department of Physics, University of California, San Diego, San Diego, CA 92093 (United States); Arai, T.; Matsumoto, T.; Matsuura, S. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Battle, J.; Hristov, V.; Lanz, A.; Levenson, L. R.; Mason, P. [Department of Physics, California Institute of Technology, Pasadena, CA 91125 (United States); Brown, S. W.; Lykke, K. R.; Smith, A. W. [Sensor Science Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Cooray, A. [Center for Cosmology, University of California, Irvine, Irvine, CA 92697 (United States); Kim, M. G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, D. H.; Nam, U. W. [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Shultz, B., E-mail: pkorngut@caltech.edu [Materion Barr Precision Optics and Thin Film Coatings, Westford, MA 01886 (United States); and others

    2013-08-15

    We have developed a near-infrared spectrometer designed to measure the absolute intensity of the solar 854.2 nm Ca II Fraunhofer line, scattered by interplanetary dust, in the zodiacal light (ZL) spectrum. Based on the known equivalent line width in the solar spectrum, this measurement can derive the zodiacal brightness, testing models of the ZL based on morphology that are used to determine the extragalactic background light in absolute photometry measurements. The spectrometer is based on a simple high-resolution tipped filter placed in front of a compact camera with wide-field refractive optics to provide the large optical throughput and high sensitivity required for rocket-borne observations. We discuss the instrument requirements for an accurate measurement of the absolute ZL brightness, the measured laboratory characterization, and the instrument performance in flight.

  3. High resolution infrared spectroscopy of planetary molecules using diode lasers and Fourier transform spectrometers

    Science.gov (United States)

    Jennings, Donald E.

    1990-01-01

    Modern observations of infrared molecular lines in planets are performed at spectral resolutions which are as high as those available in the laboratory. Analysis of such data requires laboratory measurements at the highest possible resolution, which also yield accurate line positions and intensities. For planetary purposes the spectrometer must be coupled to sample cells which can be reduced in temperature and varied in pressure. An approach which produces the full range of required molecular line parameters uses a combination of tunable diode lasers and Fourier transform spectrometers (FTS). The FTS provides board spectral coverage and good calibration accuracy, while the diode laser can be used to study those regions which are not resolved by the FTS.

  4. A low cost thermal infrared hyperspectral imager for small satellites

    Science.gov (United States)

    Crites, S. T.; Lucey, P. G.; Wright, R.; Garbeil, H.; Horton, K. A.

    2011-06-01

    The traditional model for space-based earth observations involves long mission times, high cost, and long development time. Because of the significant time and monetary investment required, riskier instrument development missions or those with very specific scientific goals are unlikely to successfully obtain funding. However, a niche for earth observations exploiting new technologies in focused, short lifetime missions is opening with the growth of the small satellite market and launch opportunities for these satellites. These low-cost, short-lived missions provide an experimental platform for testing new sensor technologies that may transition to larger, more long-lived platforms. The low costs and short lifetimes also increase acceptable risk to sensors, enabling large decreases in cost using commercial off the shelf (COTS) parts and allowing early-career scientists and engineers to gain experience with these projects. We are building a low-cost long-wave infrared spectral sensor, funded by the NASA Experimental Project to Stimulate Competitive Research program (EPSCOR), to demonstrate the ways in which a university's scientific and instrument development programs can fit into this niche. The sensor is a low-mass, power efficient thermal hyperspectral imager with electronics contained in a pressure vessel to enable the use of COTS electronics, and will be compatible with small satellite platforms. The sensor, called Thermal Hyperspectral Imager (THI), is based on a Sagnac interferometer and uses an uncooled 320x256 microbolometer array. The sensor will collect calibrated radiance data at long-wave infrared (LWIR, 8-14 microns) wavelengths in 230-meter pixels with 20 wavenumber spectral resolution from a 400-km orbit.

  5. A low cost thermal infrared hyperspectral imager for small satellites

    Science.gov (United States)

    Crites, S. T.; Lucey, P. G.; Wright, R.; Garbeil, H.; Horton, K. A.; Wood, M.

    2012-06-01

    The growth of the small satellite market and launch opportunities for these satellites is creating a new niche for earth observations that contrasts with the long mission durations, high costs, and long development times associated with traditional space-based earth observations. Low-cost, short-lived missions made possible by this new approach provide an experimental platform for testing new sensor technologies that may transition to larger, more long-lived platforms. The low costs and short lifetimes also increase acceptable risk to sensors, enabling large decreases in cost using commercial off-the-shelf (COTS) parts and allowing early-career scientists and engineers to gain experience with these projects. We are building a low-cost long-wave infrared spectral sensor, funded by the NASA Experimental Project to Stimulate Competitive Research program (EPSCoR), to demonstrate ways in which a university's scientific and instrument development programs can fit into this niche. The sensor is a low-mass, power-efficient thermal hyperspectral imager with electronics contained in a pressure vessel to enable use of COTS electronics and will be compatible with small satellite platforms. The sensor, called Thermal Hyperspectral Imager (THI), is based on a Sagnac interferometer and uses an uncooled 320x256 microbolometer array. The sensor will collect calibrated radiance data at long-wave infrared (LWIR, 8-14 microns) wavelengths in 230 meter pixels with 20 wavenumber spectral resolution from a 400 km orbit. We are currently in the laboratory and airborne testing stage in order to demonstrate the spectro-radiometric quality of data that the instrument provides.

  6. Estimating the Retrievability of Temperature Profiles from Satellite Infrared Measurements

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A method is developed to assess retrievability, namely the retrieval potential for atmospheric temperature profiles, from satellite infrared measurements in clear-sky conditions. This technique is based upon generalized linear inverse theory and empirical orthogonal function analysis. Utilizing the NCEP global temperature reanalysis data in January and July from 1999 to 2003, the retrievabilities obtained with the Atmospheric Infrared Sounder (AIRS) and the High Resolution Infrared Radiation Sounder/3 (HIRS/3)sounding channel data are derived respectively for each standard pressure level on a global scale. As an incidental result of this study, the optimum truncation number in the method of generalized linear inverse is deduced too. The results show that the retrievabilities of temperature obtained with the two datasets are similar in spatial distribution and seasonal change characteristics. As for the vertical distribution, the retrievabilities are low in the upper and lower atmosphere, and high between 400 hPa and 850 hPa. For the geographical distribution, the retrievabilities are low in the low-latitude oceanic regions and in some regions in Antarctica, and relatively high in mid-high latitudes and continental regions. Compared with the HIRS/3 data, the retrievability obtained with the AIRS data can be improved by an amount between 0.15 and 0.40.

  7. The Airborne Visible / Infrared Imaging Spectrometer AVIS: Design, Characterization and Calibration

    Directory of Open Access Journals (Sweden)

    Wolfram Mauser

    2007-09-01

    Full Text Available The Airborne Visible / Infrared imaging Spectrometer AVIS is a hyperspectralimager designed for environmental monitoring purposes. The sensor, which wasconstructed entirely from commercially available components, has been successfullydeployed during several experiments between 1999 and 2007. We describe the instrumentdesign and present the results of laboratory characterization and calibration of the system’ssecond generation, AVIS-2, which is currently being operated. The processing of the datais described and examples of remote sensing reflectance data are presented.

  8. Design and fabrication of step mirrors used in space-modulated Fourier transform infrared spectrometer.

    Science.gov (United States)

    Zheng, Ying; Liang, Jingqiu; Liang, Zhongzhu

    2013-01-14

    A model of miniaturized space-modulated Fourier transform infrared spectrometer (FTIR) is given. The two step mirrors as the key components are designed and a lithography-electroplating technique used to fabricate the small step mirror is proposed. We analyze the effect of the experiment results resulted from fabricating technics on the recovery spectrum in theory, and demonstrate that the lithography-electroplating technique is an effective method to fabricate the step mirror, which make miniaturized FTIR realized. We believe that the performances of FTIR can be better realized by optimizing experimental conditions to make this fabricating method more attractive.

  9. Planetary infrared astronomy using a cryogenic postdisperser on Fourier transform spectrometers

    Science.gov (United States)

    Jennings, D. E.; Kunde, V. G.; Hanel, R. A.; Maguire, W. C.; Lamb, G. M.

    1986-01-01

    High resolution infrared spectra of planets from ground-based observatories were analyzed and instrumentation to improve sensitivity was developed. A cryogenic postdisperser (a narrow bandpass spectral filter) for use with Fourier transform spectrometers (FTS's) at facility observatories was constructed. This instrument has improved the sensitivity of FTS observations at 8 to 20 microns by about an order of magnitude. Spectra of Jupiter, Saturn and Comet Halley were obtained using the postdisperser with FTS facilities at the Kitt Peak 4-meter and McMath telescopes. Spectral resolution as high as 0.01/cm was achieved.

  10. Design of spatio-temporally modulated static infrared imaging Fourier transform spectrometer.

    Science.gov (United States)

    Wang, WenCong; Liang, JingQiu; Liang, ZhongZhu; Lü, JinGuang; Qin, YuXin; Tian, Chao; Wang, WeiBiao

    2014-08-15

    A novel static medium wave infrared (MWIR) imaging Fourier transform spectrometer (IFTS) is conceptually proposed and experimentally demonstrated. In this system, the moving mirror in traditional temporally modulated IFTS is replaced by multi-step micro-mirrors to realize the static design. Compared with the traditional spatially modulated IFTS, they have no slit system and are superior with larger luminous flux and higher energy efficiency. The use of the multi-step micro-mirrors can also make the system compact and light.

  11. Retrieval and satellite intercomparison of O3 measurements from ground-based FTIR Spectrometer at Equatorial Station: Addis Ababa, Ethiopia

    Directory of Open Access Journals (Sweden)

    T. von Clarmann

    2013-02-01

    Full Text Available Since May 2009, high-resolution Fourier Transform Infrared (FTIR solar absorption spectra have been recorded at Addis Ababa (9.01° N latitude, 38.76° E longitude, 2443 m altitude above sea level, Ethiopia. The vertical profiles and total column amounts of ozone (O3 are deduced from the spectra by using the retrieval code PROFFIT (V9.5 and regularly determined instrumental line shape (ILS. A detailed error analysis of the O3 retrieval is performed. Averaging kernels of the target gas shows that the major contribution to the retrieved information comes from the measurement. The degrees of freedom for signals is found to be 2.1 on average for the retrieval of O3 from the observed FTIR spectra. The ozone Volume Mixing Ratio (VMR profiles and column amounts retrieved from FTIR spectra are compared with the coincident satellite observations of Microwave Limb Sounding (MLS, Michelson Interferometer for Passive Atmospheric Sounding (MIPAS, Tropospheric Emission Spectrometer (TES, Ozone Monitoring Instrument (OMI, Atmospheric Infrared Sounding (AIRS and Global Ozone Monitoring Experiment (GOME-2 instruments. The mean relative differences in ozone profiles of FTIR from MLS and MIPAS are generally lower than 15% within the altitude range of 27 to 36 km, whereas difference from TES is lower than 1%. Comparisons of measurements of column amounts from the satellite and the ground-based FTIR show very good agreement as exhibited by relative differences within +0.2% to +2.8% for FTIR versus MLS and GOME-2; and −0.9 to −9.0% for FTIR versus OMI, TES and AIRS. The corresponding standard deviations are within 2.0 to 2.8% for FTIR versus MLS and GOME-2 comparisons whereas that of FTIR versus OMI, TES and AIRS are within 3.5 to 7.3%. Thus, the retrieved O3 VMR and column amounts from a tropical site, Addis Ababa, is found to exhibit very good agreement with all coincident satellite observations over an approximate 3-yr period.

  12. Retrieval and satellite intercomparison of O3 measurements from ground-based FTIR Spectrometer at Equatorial Station: Addis Ababa, Ethiopia

    Science.gov (United States)

    Takele Kenea, S.; Mengistu Tsidu, G.; Blumenstock, T.; Hase, F.; von Clarmann, T.; Stiller, G. P.

    2013-02-01

    Since May 2009, high-resolution Fourier Transform Infrared (FTIR) solar absorption spectra have been recorded at Addis Ababa (9.01° N latitude, 38.76° E longitude, 2443 m altitude above sea level), Ethiopia. The vertical profiles and total column amounts of ozone (O3) are deduced from the spectra by using the retrieval code PROFFIT (V9.5) and regularly determined instrumental line shape (ILS). A detailed error analysis of the O3 retrieval is performed. Averaging kernels of the target gas shows that the major contribution to the retrieved information comes from the measurement. The degrees of freedom for signals is found to be 2.1 on average for the retrieval of O3 from the observed FTIR spectra. The ozone Volume Mixing Ratio (VMR) profiles and column amounts retrieved from FTIR spectra are compared with the coincident satellite observations of Microwave Limb Sounding (MLS), Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), Tropospheric Emission Spectrometer (TES), Ozone Monitoring Instrument (OMI), Atmospheric Infrared Sounding (AIRS) and Global Ozone Monitoring Experiment (GOME-2) instruments. The mean relative differences in ozone profiles of FTIR from MLS and MIPAS are generally lower than 15% within the altitude range of 27 to 36 km, whereas difference from TES is lower than 1%. Comparisons of measurements of column amounts from the satellite and the ground-based FTIR show very good agreement as exhibited by relative differences within +0.2% to +2.8% for FTIR versus MLS and GOME-2; and -0.9 to -9.0% for FTIR versus OMI, TES and AIRS. The corresponding standard deviations are within 2.0 to 2.8% for FTIR versus MLS and GOME-2 comparisons whereas that of FTIR versus OMI, TES and AIRS are within 3.5 to 7.3%. Thus, the retrieved O3 VMR and column amounts from a tropical site, Addis Ababa, is found to exhibit very good agreement with all coincident satellite observations over an approximate 3-yr period.

  13. A Comparative Analysis of the Far Infrared Spectra of Saturn's Rings and Icy Satellites with Cassini CIRS

    Science.gov (United States)

    Brooks, Shawn M.; Spilker, Linda; Edgington, Scott G.

    2016-10-01

    We will report on a campaign to observe Saturn's main rings and major icy satellites with the Composite Infrared Spectrometer onboard Cassini. CIRS' three infrared detectors cover a combined spectral range of 10 to 1400 cm-1 (1 mm down to 7 microns). We focus on data from Focal Plane 1, which covers the 10 to 600 cm-1 range (1 mm to 16 microns). The apodized spectral resolution of the instrument can be varied from 15 cm-1 to 0.5 cm-1 (Flasar et al. 2004).The spectral behavior of Saturn's main rings and icy satellites in the far infrared has been the subject of previous studies with CIRS FP1 data (Spilker at al. 2005, Carvano et al. 2007, Morishima et al. 2012). These studies have shown that the infrared spectra of these icy rings and bodies are remarkably flat between about 40 to 200 microns. Longward of this, CIRS observations, as well as older spacecraft data, show a gradual decrease in ring emissivity. This roll-off in emissivity may be due to varying optical constants of water ice, which dominates the rings' composition, as one moves towards microwave wavelengths. Carvano et al. (2007), who analyzed spectra of the icy satellites Phoebe, Iapetus, Enceladus, Tethys and Hyperion, investigated the absence of emissivity features in spectra of those satellites. This absence is intriguing, as water ice, which dominates their surface composition, contains absorption features in the FP1 spectral range. They conclude that high porosity in these satellites' regoliths may explain this lack of spectral variability.To better characterize the far infrared spectra of the rings and satellites, we have implemented a series of dedicated observations. The goal is to obtain thousands of infrared spectra at 3 cm-1 resolution of each individual ring region and as many satellites as possible. We will have more spectra than Spilker et al. had for their work at a higher spectral resolution than in the analyses of Carvano et al. and Morishima et al. A preliminary analysis of these

  14. CROMOS A cryogenic near-infrared, multi-object spectrometer for the VLT

    CERN Document Server

    Genzel, R; Tomono, D; Thatte, N; Eisenhauer, F; Lehnert, M; Tecza, M; Bender, R

    2001-01-01

    We discuss a cryogenic, multi-object near-infrared spectrometer as a second generation instrument for the VLT. The spectrometer combines 20 to 40 independent integral eld units (IFUs), which can be positioned by a cryogenic robot over the entire unvignetted eld of the VLT (~7'). Each IFU consists of a contiguous cluster of 20 to 30 pixels (0.15 to 0.25" per pixel). The individual IFUs have cold fore-optics and couple into the spectrograph with integrated bers-microlenses. The spectrometer has lambda/d-lambda~4000 and simultaneously covers the J-, H-, and K-bands with three HAWAII 2 detectors. The system is designed for operation both in seeing limited and MCAO modes. Its speed is approximately 3500 times greater than that of ISAAC and 60 times greater than NIRMOS (in H-band). The proposed instrument aims at a wide range of science, ranging from studies of galaxies/clusters in the high-z Universe (dynamics and star formation in z>1 galaxies, evolution of ellipticals, properties of distant, obscured far-IR and ...

  15. Lunar Infrared Spectrometer to Characterize the Hydration of Regolith in the Vicinity of a Lander

    Science.gov (United States)

    Ivanov, Andrey; Fedorova, Anna; Korablev, Oleg; Mantsevich, Sergey; Stepanov, Alexander; Kalinnikov, Yury

    Lunar Infrared Spectrometer (LIS) is an experiment onboard Luna-Globe (Luna 25) and Luna-Resurce (Luna 27) Russian surface missions. It is a pencil-beam spectrometer to be pointed by a robotic arm of the landing module, and is intended for study of the lunar surface composition in the vicinity of the lander. The instrument’s field of view (FOV) of 1(°) is co-aligned with the FOV (45(°) ) of a stereo TV camera. The spectrometer will provide measurements of selected surface areas in the spectral range of 1.15-3.3 mum. The spectral selection is provided by acousto-optic tunable filter (AOTF), which scans the spectral range sequentially. Electrical command of the AOTF allows selecting the spectral sampling, and permits a random access if needed. The spectral resolution is better than 25 cm (-1) . The instrument’s mass is 1.3 kg. The primary goal of the experiment is to detect the regolith hydration at 3mum, identifying its form from the shape of the spectrum, and to follow its changes during the day/shadow pattern. Also, LIS will allow to study the mineralogical composition from mineral signatures within the spectral range, and will serve for selection of samples to be analyzed by other instruments.

  16. Insights into correlation between satellite infrared information and fault activities

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Tectonic activities are accompanied with material movement and energy transfer, which definitely change the state of thermal radiation on the ground. Thus it is possible to infer present-day tectonic activities based on variations of the thermal radiation state on the ground. The received satellite infrared information is, however, likely influenced by many kinds of factors. Therefore, the first problem that needs to be solved is to extract information on tectonic activities and eliminate effects of external (non-tectonic) factors. In this study, we firstly make a review of the current studies on this subject, and then present the technical approach and our research goal.Using the data of 20 years from the infrared band of the satellite of National Oceanic and Atmospheric Administration (NOAA) and the method we have developed, we investigate fault activities in western China. The results show that the areas with high residual values of land surface brightness temperature (LSBT), which is presumably related to faultings in space, accord usually with the locations of followed major earthquakes. The times of their value growing are also roughly consistent with the beginning of active periods of earthquakes.The low frequency component fields of the LSBT, acquired from wavelet analysis, exhibit well the spatial distributions of active faults.The "heat penetrability index" (HPI) related with enhancement of subsurface thermal information has been expressed well for the backgrounds of accelerated tectonic motions, and some correlations exist between HPI and the local faulting and seismicity. This study provides a new approach to study temporal-spatial evolution of recent activities of faults and their interactions.

  17. Objective Crystal Spectrometer (OXS) for the Spectrum-X-γ satellite

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Byrnak, B.P.; Hornstrup, Allan

    1990-01-01

    The status of the Objective Crystal Spectrometer (OXS) to be flown on the Soviet Spectrum-X-Gamma satellite together with the X-ray investigation of two of the three natural crystals (LiF(220), Ge(111) and RAP(001) which are chosen as the baseline option are presented. An important result...... of this study is the approximately 50 percent higher resolution obtained by polishing the LiF(220) surface. The measured X-ray data has been used to determine the OXS specifications. A simulation of the performance of the OXS for the LiF(220)-case are presented. A novel design in which multilayers are coated...... on the LiF(220) and Ge(111) surfaces is presented. This design allows simultaneous spectroscopy in two energy bands each centered on cosmically interesting line emission regions. X-ray reflectivity measurements demonstrate that the crystal surface can be made sufficiently smooth for the application...

  18. Fiber-coupled high resolution infrared array spectrometer for the Kuiper Airborne Observatory

    Science.gov (United States)

    Glenar, D. A.; Reuter, D.; Mumma, M. J.; Chin, G.; Wiedemann, G.; Jennings, D.

    1990-01-01

    A novel cryogenic grating spectrometer (FCAS) is being designed for observations of volatiles in cometary and planetary atmospheres, and in newly forming planetary systems. The instrument features two-dimensional detector arrays coupled to a high-dispersion echelle by infrared fibers, and will achieve a spectral resolving power of about 40,000. The primary observational platform for this instrument will be the Kuiper Airborne Observatory, but it will also be configured for use at ground-based observatories. Initially, the spectrometer will use a 58 x 62, 1- to 5-micron InSb array. Larger-format IR arrays and arrays of different composition, will later be incorporated as they become available. The instrument will be used in two modes. The first uses a large format IR array in the spectral image plane for the customary one-dimensional spectral-one-dimensional spatial coverage. In the second mode, a massive, coherent bundle of infrared transmitting ZrF4 fibers will be installed after the dispersive element, to reformat the two-dimensional array into an elongated one-dimensional array for wide spectral coverage, allowing multiple lines to be measured in a single integration with high sensitivity. The overall instrument design is discussed, and the system sensitivity is estimated.

  19. Development and Airborne Operation of a Compact Water Isotope Ratio Infrared Spectrometer

    Science.gov (United States)

    Iannone, Rosario Q.; Kassi, Samir; Jost, Hans-Juerg; Chenevier, Marc; Romanini, Daniele; Meijer, Harro A. J.; Dhaniyala, Suresh; Snels, Marcel; Kerstel, Erik R. T.

    2009-01-01

    A sensitive laser spectrometer, named IRIS (water isotope ratio infrared spectrometer), was developed for the in situ detection of the isotopic composition of water vapour in the upper troposphere and the lower stratosphere. Isotope ratio measurements can be used to quantify troposphere stratosphere exchange, and to study the water chemistry in the stratosphere. IRIS is based on the technique of optical feedback cavity-enhanced absorption spectroscopy. It uses a room temperature near-infrared laser, and does not require cryogenic cooling of laser or detectors. The instrument weighs 51 kg including its support structure. Airborne operation was demonstrated during three flights aboard the European M55-Geophysica stratospheric research aircraft, as part of the AMMA/SCOUT-03 (African Monsoon Multidisciplinary Analysis/Stratospheric Climate links with emphasis on the Upper Troposphere and lower stratosphere) campaign in Burkina Faso in August 2006. The data are discussed with reference to a Rayleigh distillation model. As expected, there is no indication of non-mass-dependent fractionation (also known as mass-independent fractionation) in the troposphere. Furthermore, improvements to the thermal management system and a move to a (cryogen-free) longer-wavelength laser source are discussed, which together should result in approximately two orders of magnitude improvement of the sensitivity

  20. Spectra Transfer Between a Fourier Transform Near-Infrared Laboratory and a Miniaturized Handheld Near-Infrared Spectrometer.

    Science.gov (United States)

    Hoffmann, Uwe; Pfeifer, Frank; Hsuing, Chang; Siesler, Heinz W

    2016-05-01

    The aim of this contribution is to demonstrate the transfer of spectra that have been measured on two different laboratory Fourier transform near-infrared (FT-NIR) spectrometers to the format of a handheld instrument by measuring only a few samples with both spectrometer types. Thus, despite the extreme differences in spectral range and resolution, spectral data sets that have been collected and quantitative as well as qualitative calibrations that have been developed thereof, respectively, over a long period on a laboratory instrument can be conveniently transferred to the handheld system. Thus, the necessity to prepare completely new calibration samples and the effort required to develop calibration models when changing hardware platforms is minimized. The enabling procedure is based on piecewise direct standardization (PDS) and will be described for the data sets of a quantitative and a qualitative application case study. For this purpose the spectra measured on the FT-NIR laboratory spectrometers were used as "master" data and transferred to the "target" format of the handheld instrument. The quantitative test study refers to transmission spectra of three-component liquid solvent mixtures whereas the qualitative application example encompasses diffuse reflection spectra of six different current polymers. To prove the performance of the transfer procedure for quantitative applications, partial least squares (PLS-1) calibrations were developed for the individual components of the solvent mixtures with spectra transferred from the master to the target instrument and the cross-validation parameters were compared with the corresponding parameters obtained for spectra measured on the master and target instruments, respectively. To test the retention of the discrimination ability of the transferred polymer spectra sets principal component analyses (PCAs) were applied exemplarily for three of the six investigated polymers and their identification was demonstrated by

  1. [Design and study of a high resolution vacuum ultraviolet imaging spectrometer carried by satellite].

    Science.gov (United States)

    Yu, Lei; Lin, Guan-yu; Qu, Yi; Wang, Shu-rong; Wang, Long-qi

    2011-12-01

    A high resolution vacuum ultraviolet imaging spectrometer prototype carried by satellite applied to the atmosphere detection of particles distribution in 115-300 nm was developed for remote sensing. First, based on the analysis of advanced loads, the optical system including an off-axis parabolic mirror as the telescope and Czerny-Turner structure as the imaging spectrometer was chosen Secondly, the 2-D photon counting detector with MCP was adopted for the characteristic that the radiation is weak in vacuum ultraviolet waveband. Then the geometric method and 1st order differential calculation were introduced to improve the disadvantages that aberrations in the traditional structure can not be corrected homogeneously to achieve perfect broadband imaging based on the aberration theory. At last, an advanced example was designed. The simulation and calculation of results demonstrate that the modulation transfer function (MTF) of total field of view is more than 0.6 in the broadband, and the spectral resolution is 1.23 nm. The structure is convenient and predominant. It proves that the design is feasible.

  2. Micro-spec: an Integrated Direct-detection Spectrometer for Far-infrared Space Telescopes

    Science.gov (United States)

    Cataldo, Giuseppe; Hsieh, Wen-Ting; Huang, Wei-Chung; Moseley, S. Harvey; Stevenson, Thomas R.; Wollack, Edward J.

    2014-01-01

    The far-infrared and submillimeter portions of the electromagnetic spectrum provide a unique view of the astrophysical processes present in the early universe. Our ability to fully explore this rich spectral region has been limited, however, by the size and cost of the cryogenic spectrometers required to carry out such measurements.Micro-Spec (µ-Spec) is a high-sensitivity, direct-detection spectrometer concept working in the 450-1000 (micrometers) wavelength range which will enable a wide range of flight missions that would otherwise be challenging due tothe large size of current instruments with the required spectral resolution and sensitivity. The spectrometer design utilizes two internal antenna arrays, one for transmitting and one for receiving, superconducting microstrip transmission lines for power division and phase delay, and an array of microwave kinetic inductance detectors (MKIDs) to achieve these goals. The instrument will be integrated on a approximately 10 sq cm silicon chip and can therefore become an important capability under the low background conditions accessible via space and high-altitude borne platforms. In this paper, an optical design methodology for micro-Spec is presented, with particular attention given to its two-dimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the maximization of the instrument resolving power and minimization of the RMS phase error on the instrument focal plane. This two-step optimization can generate geometrical configurations given specific requirements on spectrometer size, operating spectral range and performance.Two point designs with resolving power of 260 and 520 and an RMS phase error less than approximately 0.004 radians were developed for initial demonstration and will be the basis of future instruments with resolving power up to about 1200.

  3. Micro-Spec: an Integrated, Direct-Detection Spectrometer for Far-Infrared and Submillimeter Astronomy

    Science.gov (United States)

    Cataldo, Giuseppe

    2014-01-01

    The far-infrared and submillimeter portions of the electromagnetic spectrum provide a unique view of the astrophysical processes present in the early universe. Our ability to fully explore this rich spectral region has been limited, however, by the size and cost of the cryogenic spectrometers required to carry out such measurements. Micro-Spec (u-Spec) is a high-sensitivity, direct-detection spectrometer concept working in the 450-1000 micromillimeter wavelength range which will enable a wide range of flight missions that would otherwise be challenging due to the large size of current instruments with the required spectral resolution and sensitivity. The spectrometer design utilizes two internal antenna arrays, one for transmitting and one for receiving, superconducting microstrip transmission lines for power division and phase delay, and an array of microwave kinetic inductance detectors (MKIDs) to achieve these goals. The instrument will be integrated on a approximately 10 square cm silicon chip and can therefore become an important capability under the low background conditions accessible via space and high-altitude borne platforms. In this paper, an optical design methodology for Micro-Spec is presented, with particular attention given to its twodimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the maximization of the instrument resolving power and minimization of the RMS phase error on the instrument focal plane. This two-step optimization can generate geometrical configurations given specific requirements on spectrometer size, operating spectral range and performance. A point design with resolving power of 257, an RMS phase error less than 0.1 radians and four stigmatic points was developed for initial demonstration and will be the basis of future instruments with resolving power up to about 1200.

  4. Multi-channel up-conversion infrared spectrometer and method of detecting a spectral distribution of light

    DEFF Research Database (Denmark)

    2015-01-01

    A multi-channel infrared spectrometer for detecting an infrared spectrum of light received from an object. The spectrometer comprises a wavelength converter system comprising a nonlinear material and having an input side and an output side. The wavelength converter system comprises at least a first...... on the first side into light in a second output wavelength range output on the second side. The spectrometer further comprises a demultiplexer configured for demultiplexing light in the first up-conversion channel and light in the second up-conversion channel. The demultiplexer is located on the first side...... or the second side of the wavelength converter system. Finally, the spectrometer comprises a spatially resolved detector arranged in the image plane to detect light in the first output wavelength range and second output wavelength range output of the wavelength converter system....

  5. Thermal Emission Variability of Zamama, Culann and Tupan on Io Using Galileo Near-Infrared Mapping Spectrometer (NIMS) Data

    Science.gov (United States)

    Ennis, M. E.; Davies, A. G.

    2005-01-01

    The Jovian satellite Io is the most volcanically active body in the Solar System. Previous analyses [e.g., 1-4] indicate the presence of high-temperature silicate volcanism on Io, similar to silicate volcanism occurring on Earth. Instruments onboard the Galileo spacecraft, especially the Near Infrared Mapping Spectrometer (NIMS) and the Solid State Imager (SSI), provided much data of Io s active volcanoes throughout the duration of the Galileo mission (June 1996-September 2003). NIMS data is particularly sensitive to thermal emission from active and cooling lava over cooling times of seconds to a few years. The objective of this ongoing study of Io s volcanism is to determine the variability of thermal emission from volcanoes on Io s surface, in order to better understand the styles of eruption, and to constrain the volumes of material erupted. Ultimately, this will help to constrain the contribution of active volcanism to Io s thermal budget. Data have been analyzed for the volcano Zamama, located at 173 W, 21 N, and the power output of Zamama, the volumes of lava being erupted, and the eruption rate determined. Culann and Tupan have also been analysed in this way. This abstract primarily concentrates on Zamama.

  6. Qualification study of LiF flight crystals for the objective crystal spectrometer on the SPECTRUM-X-GAMMA satellite

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Rasmussen, I.; Schnopper, Herbert W.;

    1992-01-01

    The Objective Crystal Spectrometer (OXS) on the SPECTRUM-X-GAMMA satellite will carry these types of natural crystals LiF(220), Ge(111) and RAP(001). They will be used to study, among others, the H- and the He-like emission from the cosmically important elements Fe, S, Ar and O. More than 300 Li...

  7. Development of Real-Time Image Stabilization for an Airborne Infrared Spectrometer

    Science.gov (United States)

    Fedeler, Samuel; Samra, Jenna; Guth, Giora

    2017-01-01

    The total solar eclipse of August 21, 2017 offers a unique opportunity for study of the infrared solar corona. The Airborne Infrared Spectrometer (AIR-Spec), currently under development, is an infrared telescope and spectrometer that will search for several magnetically sensitive coronal emission lines between 1.4 and 4 micrometers. This instrument will be the first to observe several of these lines, and the measurement campaign will determine whether any lines may be useful for future direct observations of the coronal magnetic field. AIR-Spec will be mounted on an NSF/NCAR Gulfstream V jet and will observe the eclipse from an altitude greater than 14.9 km, above the bulk of IR-absorbing atmospheric water vapor.To ensure that the images taken for analysis have adequate spatial resolution, the AIR-Spec line-of-sight must be stabilized to 1.9 arc-seconds RMS over a 1 second exposure time. Image stabilization is achieved by using a fiber-optic gyroscope to measure aircraft rotation and a fast-steering mirror to adjust the line-of-sight accordingly. The stabilization algorithm runs in a programmable automation controller, which interfaces with the gyroscope and mirror. Software was developed to implement the stabilization algorithm in the controller and to integrate the controller with a user interface, allowing for data display and logging, user guided attitude calibration, and manual control of the fast-steering mirror. The current system stabilizes images to 1.9 arc-seconds in 60 percent of 1 second camera exposures under laboratory conditions. This software will be operational during test flights in Fall 2016 and Spring 2017, and will be optimized for the eclipse flight in Summer 2017.

  8. Search for and limits on plume activity on Mimas, Tethys, and Dione with the Cassini Visual Infrared Mapping Spectrometer (VIMS)

    Science.gov (United States)

    Buratti, B.J.; Faulk, S.P.; Mosher, J.; Baines, K.H.; Brown, R.H.; Clark, R.N.; Nicholson, P.D.

    2011-01-01

    Cassini Visual Infrared Mapping Spectrometer (VIMS) observations of Mimas, Tethys, and Dione obtained during the nominal and extended missions at large solar phase angles were analyzed to search for plume activity. No forward scattered peaks in the solar phase curves of these satellites were detected. The upper limit on water vapor production for Mimas and Tethys is one order of magnitude less than the production for Enceladus. For Dione, the upper limit is two orders of magnitude less, suggesting this world is as inert as Rhea (Pitman, K.M., Buratti, B.J., Mosher, J.A., Bauer, J.M., Momary, T., Brown, R.H., Nicholson, P.D., Hedman, M.M. [2008]. Astrophys. J. Lett. 680, L65-L68). Although the plumes are best seen at ???2.0. ??m, Imaging Science Subsystem (ISS) Narrow Angle Camera images obtained at the same time as the VIMS data were also inspected for these features. None of the Cassini ISS images shows evidence for plumes. The absence of evidence for any Enceladus-like plumes on the medium-sized saturnian satellites cannot absolutely rule out current geologic activity. The activity may below our threshold of detection, or it may be occurring but not captured on the handful of observations at large solar phase angles obtained for each moon. Many VIMS and ISS images of Enceladus at large solar phase angles, for example, do not contain plumes, as the active "tiger stripes" in the south pole region are pointed away from the spacecraft at these times. The 7-year Cassini Solstice Mission is scheduled to gather additional measurements at large solar phase angles that are capable of revealing activity on the saturnian moons. ?? 2011 Elsevier Inc.

  9. Development of long wavelength semiconductor diode lasers near 28 microns for use in infrared heterodyne spectrometers

    Science.gov (United States)

    Linden, K. J.

    1984-01-01

    The development of tunable diode lasers operating in the 28 micrometers spectral region for use in infrared heterodyne spectrometers is reported. A process capable of yielding lasers emitting 500 micron W of multimode power, 112 micron W in a true single mode and true single mode operation at laser currents of up to 35% above threshold was developed. Results were obtained from narrow mesastripe (20 micrometer wide) short cavity (120 micrometer length) laser configurations. Six stripe geometry lasers, with a variety of cavity widths and lengths were delivered. The techniques to fabricate such devices was obtained and the long term reliability of such lasers by reproducible electrical and optical output characteristics fabrication from lasers are demonstrated.

  10. Short wavelength spectrometer for the Infrared Space Observatory (ISO). A proposal to the European Space Agency

    Science.gov (United States)

    A spectrometer for the Infrared Space Observatory, designed to operate in the wavelength region from 3 to 50 microns with resolutions ranging from 3000 to 100,000 is proposed. It can study interstellar matter, star formation and evolution, extragalactic systems, and the solar system. The wide wavelength range includes numerous atomic, ionic and molecular transitions as well as diffuse features. They provide tools for studies of the physical and chemical processes of regions optically hidden by interstellar dust. The high resolving power allows probing of kinematic processes objects ranging from galactic nuclei to planetary atmospheres. Line studies of extragalactic objects, out to distances equal to the Virgo cluster, can be carried out. Direct observation of ground state molecular hydrogen in the interstellar medium can be attempted.

  11. Instrument performance for IIP Tropospheric Infrared Mapping Spectrometers (TIMS) for vertically resolved CO

    Science.gov (United States)

    Roche, A. E.; Kumer, J. B.; Rairden, R. L.; Jamieson, T. H.; Mergenthaler, J. L.

    2008-12-01

    The NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) Tropospheric Infrared Mapping Spectrometers (TIMS) have been developed to demonstrate measurement capability, when deployed in space, for multi-layer retrieval of CO from spectral measurements acquired in the solar reflective band ~ 4281 to 4301 cm-1 and in the thermal band ~ 2110 to 2165 cm-1. The presentation will describe [a] the top level designs [b] measured instrument performance parameters including spectral and spatial resolution, spectral quality and noise performance, [c] comparisons of the performance (spectral, spatial, noise) with instrument modeling and [d] calibration procedures and results for spectral registration, spectral response, flat fielding, zero level determination and radiometric. Good comparison with demonstration instrument performance and modeling gives a high level of confidence for instrument performance in the space based case. Lessons learned will be described. These are very valuable for the space deployed application. The TIMS are well suited for either LEO or GEO application.

  12. Application of support vector machine and particle swarm optimization in micro near infrared spectrometer

    Science.gov (United States)

    Xiong, Yuhong; Liu, Yunxiang; Shu, Minglei

    2016-10-01

    In the process of actual measurement and analysis of micro near infrared spectrometer, genetic algorithm is used to select the wavelengths and then partial least square method is used for modeling and analyzing. Because genetic algorithm has the disadvantages of slow convergence and difficult parameter setting, and partial least square method in dealing with nonlinear data is far from being satisfactory, the practical application effect of partial least square method based on genetic algorithm is severely affected negatively. The paper introduces the fundamental principles of particle swarm optimization and support vector machine, and proposes a support vector machine method based on particle swarm optimization. The method can overcome the disadvantage of partial least squares method based on genetic algorithm to a certain extent. Finally, the method is tested by an example, and the results show that the method is effective.

  13. The GIS data model of the Visible and Infrared mapping spectrometer (VIR) onboard NASA/Dawn

    Science.gov (United States)

    Frigeri, Alessandro; De Sanctis, Maria Cristina; Ammannito, Eleonora; Capaccioni, Fabrizio; VIR Team

    2016-10-01

    The spectrometer onboard Dawn mission to Vesta and Ceres (Russell et al., Earth Moon Planet (2007) 101:65-91) is a hyperspectral spectrometer with imaging capability which returns data useful for the determination of the mineral composition of surface materials in their geologic context. The VIR Spectrometer—covering the range from the near UV (0.25 μm) to the near IR (5.0 μm) and having moderate to high spectral resolution and imaging capabilities—is the appropriate instrument for the determination of Vesta's and Ceres' global and local properties (De Sanctis et al., SSR 2011). VIR combines two data channels in one compact instrument. The visible channel covers 0.25-1.05 μm and the infrared channel covers 1-5.0 μm. VIR is inherited from the VIRTIS mapping spectrometer (Coradini et al. in Planet. Space Sci. 46:1291-1304, 1998; Reininger et al. in Proc. SPIE 2819:66-77, 1996) on board the ESA Rosetta mission.Since the beginning of the scientific campaign, VIR calibrated data have been converted into a Geographic Information System (GIS) compatible format. Here we present the GIS data model we developed for VIR, which presents some unique peculiarities due to the specific NASA/Dawn mission design. The model has been developed starting from an object oriented modeling. This object oriented design gives the flexibility which is necessary to face, time to time, the unexpected aspects of remote sensing over planetary surfaces unobserved before with this kind of instruments.

  14. Integration, Testing and Performance of the Infrared Multi-Object Spectrometer

    Science.gov (United States)

    Ohl, Raymond G.; Connelly, Joseph A.; Boyle, Robert F.; Derro, Rebecca J.; Greenhouse, Matthew A.; Madison, Timothy J.; Mentzell, J. Eric; Sparr, Leroy M.; Hylan, Jason E.; Ray, Knute

    2003-01-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a principle investigator-class instrument for the Kitt Peak National Observatory 2.1 m and Mayall 3.8 m telescopes. IRMOS is a near-IR (0.8 - 2.5 micron) spectrometer with low-to mid-resolving power (R = lambda/delta lambda = 300 - 3000). On the 3.8 m telescope, IRMOS produces simultaneous spectra of approximately 100 objects in its approximately 3 x 2 arcmin field of view using a commercial micro electro-mechanical systems (MEMS) digital micro-mirror device (DMD) from Texas Instruments. The multi-mirror array DMD operates as a real-time programmable slit mask. The all-reflective optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the DMD field stop, and the spectrograph images the DMD onto a large-format detector. The instrument operates at approximately 80 K, cooled by a single electro-mechanical cryocooler. The bench and all components are made from aluminum 6061-T651. There are three cryogenic mechanisms. We describe laboratory integration and test of IRMOS before shipment to Kitt Peak. We give an overview of the optical alignment technique and integration of optical, mechanical, electrical and cryogenic subsystems. We compare optical test results to model predictions of point spread function size and morphology, contrast, and stray light. We discuss some lessons learned and conclude with a prediction for performance on the telescope.

  15. Absolutely nondestructive discrimination of Huoshan Dendrobium nobile species with miniature near-infrared (NIR) spectrometer engine.

    Science.gov (United States)

    Hu, Tian; Yang, Hai-Long; Tang, Qing; Zhang, Hui; Nie, Lei; Li, Lian; Wang, Jin-Feng; Liu, Dong-Ming; Jiang, Wei; Wang, Fei; Zang, Heng-Chang

    2014-10-01

    As one very precious traditional Chinese medicine (TCM), Huoshan Dendrobium has not only high price, but also significant pharmaceutical efficacy. However, different species of Huoshan Dendrobium exhibit considerable difference in pharmaceutical efficacy, so rapid and absolutely non-destructive discrimination of Huoshan Dendrobium nobile according to different species is crucial to quality control and pharmaceutical effect. In this study, as one type of miniature near-infrared (NIR) spectrometer, MicroNIR 1700 was used for absolutely nondestructive determination of NIR spectra of 90 batches of Dendrobium from five species of differ- ent commodity grades. The samples were intact and not smashed. Soft independent modeling of class analogy (SIMCA) pattern recognition based on principal component analysis (PCA) was used to classify and recognize different species of Dendrobium samples. The results indicated that the SIMCA qualitative models established with pretreatment method of standard normal variate transformation (SNV) in the spectra range selected by Qs method had 100% recognition rates and 100% rejection rates. This study demonstrated that a rapid and absolutely non-destructive analytical technique based on MicroNIR 1700 spectrometer was developed for successful discrimination of five different species of Huoshan Dendrobium with acceptable accuracy.

  16. Short-Wave Near-Infrared Spectrometer for Alcohol Determination and Temperature Correction

    Directory of Open Access Journals (Sweden)

    Qingbo Fu

    2012-01-01

    Full Text Available A multichannel short-wave near-infrared (SW-NIR spectrometer module based on charge-coupled device (CCD detection was designed. The design relied on a tungsten lamp enhanced by light emitting diodes, a fixed grating monochromator and a linear CCD array. The main advantages were high optical resolution and an optimized signal-to-noise ratio (0.24 nm and 500, resp. in the whole wavelength range of 650 to 1100 nm. An application to alcohol determination using partial least squares calibration and the temperature correction was presented. It was found that the direct transfer method had significant systematic prediction errors due to temperature effect. Generalized least squares weighting (GLSW method was utilized for temperature correction. After recalibration, the RMSEP found for the 25°C model was 0.53% v/v and errors of the same order of magnitude were obtained at other temperatures (15, 35 and 40°C. And an 2 better than 0.99 was achieved for each validation set. The possibility and accuracy of using the miniature SW-NIR spectrometer and GLSW transfer calibration method for alcohol determination at different temperatures were proven. And the analysis procedure was simple and fast, allowing a strict control of alcohol content in the wine industry.

  17. Micro-Spec: An Ultracompact, High-sensitivity Spectrometer for Far-Infrared and Submillimeter Astronomy

    Science.gov (United States)

    Cataldo, Giuseppe; Hsieh, Wen-Ting; Huang, Wei-Chung; Moseley, S. Harvey; Stevenson, Thomas R.; Wollack, Edward J.

    2014-01-01

    High-performance, integrated spectrometers operating in the far-infrared and submillimeter ranges promise to be powerful tools for the exploration of the epochs of reionization and initial galaxy formation. These devices, using high-efficiency superconducting transmission lines, can achieve the performance of a meter-scale grating spectrometer in an instrument implemented on a 4 inch silicon wafer. Such a device, when combined with a cryogenic telescope in space, provides an enabling capability for studies of the early universe. Here, the optical design process for Micro-Spec (micron-Spec) is presented, with particular attention given to its two-dimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the stigmatization and minimization of the light path function in this bounded region, which results in an optimized geometrical configuration. A point design with an efficiency of (is) approximately 90% has been developed for initial demonstration and can serve as the basis for future instruments. Design variations on this implementation are also discussed, which can lead to lower efficiencies due to diffractive losses in the multimode region.

  18. Portable Gas Analyzer Based on Fourier Transform Infrared Spectrometer for Patrolling and Examining Gas Exhaust

    Directory of Open Access Journals (Sweden)

    Yuntao Liang

    2015-01-01

    Full Text Available Aimed at monitoring emission of organic gases such as CH4, C2H6, C3H8, iso-C4H10, n-C4H10, C2H4, C3H6, C2H2, CO, and CO2, from coal mines, petroleum refineries, and other plants, a Fourier Transform Infrared (FT-IR spectrometer was used to develop a portable gas analyzer for patrolling and examining gas exhaust. Firstly, structure of the instrument was introduced. Then, a spectral analysis approach was presented. Finally, instrument was tested with standard gases and with actual gases emitted from a petroleum refinery. For the latter test, a gas chromatograph (GC was used as a reference instrument. The test results showed that the detection limit of every component of analyte was less than 10 × 10−6. The maximum test error of every analyte was less than 15 × 10−6 when its practical concentration was no more than 500 × 10−6. A final comparison showed that the result curves of analytes obtained with FT-IR spectrometer almost overlapped with those obtained with GC, and their resulting noise was less than 6.4% when the practical gas concentration was above 100 × 10−6. As a result, our instrument was suitable to be used as a portable instrument for monitoring exhaust gases.

  19. Scientific objectives and selection of targets for the SMART-1 Infrared Spectrometer (SIR)

    Science.gov (United States)

    Basilevsky, A. T.; Keller, H. U.; Nathues, A.; Mall, U.; Hiesinger, H.; Rosiek, M.

    2004-12-01

    The European SMART-1 mission to the Moon, primarily a testbed for innovative technologies, was launched in September 2003 and will reach the Moon in 2005. On board are several scientific instruments, including the point-spectrometer SMART-1 Infrared Spectrometer (SIR). Taking into account the capabilities of the SMART-1 mission and the SIR instrument in particular, as well as the open questions in lunar science, a selection of targets for SIR observations has been compiled. SIR can address at least five topics: (1) Surface/regolith processes; (2) Lunar volcanism; (3) Lunar crust structure; (4) Search for spectral signatures of ices at the lunar poles; and (5) Ground truth and study of geometric effects on the spectral shape. For each topic we will discuss specific observation modes, necessary to achieve our scientific goals. The majority of SIR targets will be observed in the nadir-tracking mode. More than 100 targets, which require off-nadir pointing and off-nadir tracking, are planned. It is expected that results of SIR observations will significantly increase our understanding of the Moon. Since the exact arrival date and the orbital parameters of the SMART-1 spacecraft are not known yet, a more detailed planning of the scientific observations will follow in the near future.

  20. Five-Channel Infrared Laser Absorption Spectrometer for Combustion Product Monitoring Aboard Manned Spacecraft

    Science.gov (United States)

    Briggs, Ryan M.; Frez, Clifford; Borgentun, Carl E.; Bagheri, Mahmood; Forouhar, Siamak; May, Randy D.

    2014-01-01

    Continuous combustion product monitoring aboard manned spacecraft can prevent chronic exposure to hazardous compounds and also provides early detection of combustion events. As future missions extend beyond low-Earth orbit, analysis of returned environmental samples becomes impractical and safety monitoring should be performed in situ. Here, we describe initial designs of a five-channel tunable laser absorption spectrometer to continuously monitor combustion products with the goal of minimal maintenance and calibration over long-duration missions. The instrument incorporates dedicated laser channels to simultaneously target strong mid-infrared absorption lines of CO, HCl, HCN, HF, and CO2. The availability of low-power-consumption semiconductor lasers operating in the 2 to 5 micron wavelength range affords the flexibility to select absorption lines for each gas with maximum interaction strength and minimal interference from other gases, which enables the design of a compact and mechanically robust spectrometer with low-level sensitivity. In this paper, we focus primarily on absorption line selection based on the availability of low-power single-mode semiconductor laser sources designed specifically for the target wavelength range.

  1. On-line near-infrared spectrometer to monitor urea removal in real time during hemodialysis.

    Science.gov (United States)

    Cho, David S; Olesberg, Jonathon T; Flanigan, Michael J; Arnold, Mark A

    2008-08-01

    The ex vivo removal of urea during hemodialysis treatments is monitored in real time with a noninvasive near-infrared spectrometer. The spectrometer uses a temperature-controlled acousto optical tunable filter (AOFT) in conjunction with a thermoelectrically cooled extended wavelength InGaAs detector to provide spectra with a 20 cm(-1) resolution over the combination region (4000-5000 cm(-1)) of the near-infrared spectrum. Spectra are signal averaged over 15 seconds to provide root mean square noise levels of 24 micro-absorbance units for 100% lines generated over the 4600-4500 cm(-1) spectral range. Combination spectra of the spent dialysate stream are collected in real-time as a portion of this stream passes through a sample holder constructed from a 1.1 mm inner diameter tube of Teflon. Real-time spectra are collected during 17 individual dialysis sessions over a period of 10 days. Reference samples were extracted periodically during each session to generate 87 unique samples with corresponding reference concentrations for urea, glucose, lactate, and creatinine. A series of calibration models are generated for urea by using the partial least squares (PLS) algorithm and each model is optimized in terms of number of factors and spectral range. The best calibration model gives a standard error of prediction (SEP) of 0.30 mM based on a random splitting of spectra generated from all 87 reference samples collected across the 17 dialysis sessions. PLS models were also developed by using spectra collected in early sessions to predict urea concentrations from spectra collected in subsequent sessions. SEP values for these prospective models range from 0.37 mM to 0.52 mM. Although higher than when spectra are pooled from all 17 sessions, these prospective SEP values are acceptable for monitoring the hemodialysis process. Selectivity for urea is demonstrated and the selectivity properties of the PLS calibration models are characterized with a pure component selectivity

  2. Spherical grating spectrometers

    Science.gov (United States)

    O'Donoghue, Darragh; Clemens, J. Christopher

    2014-07-01

    We describe designs for spectrometers employing convex dispersers. The Offner spectrometer was the first such instrument; it has almost exclusively been employed on satellite platforms, and has had little impact on ground-based instruments. We have learned how to fabricate curved Volume Phase Holographic (VPH) gratings and, in contrast to the planar gratings of traditional spectrometers, describe how such devices can be used in optical/infrared spectrometers designed specifically for curved diffraction gratings. Volume Phase Holographic gratings are highly efficient compared to conventional surface relief gratings; they have become the disperser of choice in optical / NIR spectrometers. The advantage of spectrometers with curved VPH dispersers is the very small number of optical elements used (the simplest comprising a grating and a spherical mirror), as well as illumination of mirrors off axis, resulting in greater efficiency and reduction in size. We describe a "Half Offner" spectrometer, an even simpler version of the Offner spectrometer. We present an entirely novel design, the Spherical Transmission Grating Spectrometer (STGS), and discuss exemplary applications, including a design for a double-beam spectrometer without any requirement for a dichroic. This paradigm change in spectrometer design offers an alternative to all-refractive astronomical spectrometer designs, using expensive, fragile lens elements fabricated from CaF2 or even more exotic materials. The unobscured mirror layout avoids a major drawback of the previous generation of catadioptric spectrometer designs. We describe laboratory measurements of the efficiency and image quality of a curved VPH grating in a STGS design, demonstrating, simultaneously, efficiency comparable to planar VPH gratings along with good image quality. The stage is now set for construction of a prototype instrument with impressive performance.

  3. A Static Imaging Fourier Transform Spectrometer (SIFTS) for infrared remote sensing

    Science.gov (United States)

    Mortimer, Hugh; Hussain, Ali

    2017-04-01

    A Static Imaging Fourier Transform Spectrometer, SIFTS, has been developed for hyperspectral remote sensing in the infrared. The compact instrument has no moving components and so is insensitive to vibration. It has been optimised for operation from the Near (3 microns) to Mid Infrared (15 microns) through the use of an uncooled, wideband microbolometer detector array. The resolution across this spectral range has been shown to be 8cm-1. This instrument is inherently imaging, whereby spectral information is recorded along the of the detector array whilst imaging information is recorded down the column of the detector array. The Connes advantage, inherent to the Michelson spectrometer Fourier Transform Spectrometer (FTS), whereby the spectral wavelength accuracy is referenced to a stabilised laser has also been demonstrated in the SIFTS instrument. This has been implemented through the use of an expanded internal laser diode with Distributed Bragg Reflector (DFB) which acts as the calibration source used to maintain the wavelength stability of the SIFTS instrument. As there are no moving components, the instrument is compact, light and insensitive to mechanical vibration, additionally the speed of measurement is determined by the frame rate of the detector array. Thus, this instrument has a temporal advantage over common Michelson FTIR instruments. The novel optical design has reduced the optics to only 3 optical components, and the detector array, to generate and measure the interferogram. The experimental performance of the SIFTS instrument is demonstrated in measurements against theoretical and The technique is based on a static optical configuration whereby light is split into two paths and made to recombine along a focal plane producing an interference pattern. The spectral information is returned using a detector array to digitally capture the interferogram which can then be processed into a spectrum by applying a Fourier transform. As there are no moving

  4. A collinear tandem time-of-flight mass spectrometer for infrared photodissociation spectroscopy of mass-selected ions

    Institute of Scientific and Technical Information of China (English)

    WANG GuanJun; CHI ChaoXian; XING XiaoPeng; DING ChuanFan; ZHOU MingFei

    2014-01-01

    An apparatus based on collinear tandem time-of-flight mass spectrometer has been designed for the measurement of infrared photodissociation spectroscopy of mass-selected ions in the gas phase.The ions from a pulsed laser vaporization supersonic ion source are skimmed and mass separated by a Wiley-McLaren time-of-flight mass spectrometer.The ion of interest is mass selected,decelerated and dissociated by a tunable IR laser.The fragment and parent ions are reaccelerated and mass analyzed by the second time-of-flight mass spectrometer.A simple new assembly integrated with mass gate,deceleration and reacceleration ion optics was designed,which allows us to measure the infrared spectra of mass selected ions with high sensitivity and easy timing synchronization.

  5. Alignment and Polarization Sensitivity Study for the Cassini-Composite InfraRed Spectrometer (CIRS) Far InfraRed (FIR) Interferometer

    Science.gov (United States)

    Crooke, Julie A.; Hagopian, John G.

    1998-01-01

    The Composite InfraRed Spectrometer (CIRS) instrument flying on the Cassini spacecraft to Saturn is a cryogenic spectrometer with far-infrared (FIR) and mid-infrared (MIR) channels. The CIRS FIR channel is a polarizing interferometer that contains three polarizing grid components. These components are an input polarizer, a polarizing beamsplitter, and an output polarizer/analyzer. They consist of a 1.5 micron thick mylar substrate with 2 gm wide copper wires, with 2 gm spacing (4 micron pitch) photolithographically deposited on the substrate. This paper details the polarization sensitivity studies performed on the output polarizer/analyzer, and the alignment sensitivity studies performed on the input polarizer and beamsplitter components in the FIR interferometer.

  6. Multidimensional spectrometer

    Science.gov (United States)

    Zanni, Martin Thomas; Damrauer, Niels H.

    2010-07-20

    A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

  7. On-site isotopic analysis of dissolved inorganic carbon using an isotope ratio infrared spectrometer

    Science.gov (United States)

    Stoltmann, Tim; Mandic, Magda; Stöbener, Nils; Wapelhorst, Eric; Aepfler, Rebecca; Hinrichs, Kai-Uwe; Taubner, Heidi; Jost, Hj; Elvert, Marcus

    2016-04-01

    An Isotope Ratio Infrared Spectrometer (IRIS) has been adapted to perform measurements of δ13C of dissolved inorganic carbon (DIC) in marine pore waters. The resulting prototype allowed highly automated analysis of δ13C isotopic ratios and CO2 concentration. We achieved a throughput of up to 70 samples per day with DIC contents as low as 1.7 μmol C. We achieved an internal precision of 0.066 ‰ and an external precision of 0.16 ‰, which is comparable to values given for Isotope Ratio Mass Spectrometers (IRMS). The prototype instrument is field deployable, suitable for shipboard analysis of deep sea core pore waters. However, the validation of the prototype was centered around a field campaign in Eckernförde Bay, NW- Baltic Sea. As a proof of concept, a shallow site within an area of submarine groundwater discharge (SGD) and a site outside this area was investigated. We present profiles of δ13C of DIC over 50 cm exhibiting well understood methane turnover processes (anaerobic oxidation of methane). At the lowest point below the seafloor, microbial reduction of CO2 to CH4 dominates. 12CO2 is reduced preferentially over 13CO2, leading to more positive δ13C values in the remaining DIC pool; in layers closer to the surface, the oxidation of CH4 to CO2 becomes more prominent. Since the CH4 pool is enriched in 12C a shift to more negative δ13C can be observed in the DIC pool. In the upper 15 cm, the pore water DIC mixes with the sea water DIC, increasing δ13C again. Finally, we will present recent developments to further improve performance and future plans for deployments on research cruises.

  8. ISIS Cartographic Tools for the Dawn Framing Camera and Visual and Infrared Spectrometer

    Science.gov (United States)

    Anderson, J.; Becker, K. J.; Titus, T. N.; De sanctis, M.; Nathues, A.; Tosi, F.; Schroeder, S.; Le Corre, L.; Kelley, M. S.; Raymond, C. A.; Russell, C. T.

    2011-12-01

    Launched in September 2007, the Dawn spacecraft houses two imaging instruments: the framing camera (FC) and the Visual and Infrared Spectrometer (VIR) [1]. The spacecraft began orbiting asteroid 4 Vesta in July 2011 and over the course of one year will systematically map the body with both instruments. Camera model software and Dawn FC and VIR readers have been developed in the USGS Integrated Software for Imager and Spectrometers (ISIS) [2]. The readers, "dawnfc2isis" and "dawnvir2isis", convert both Planetary Data System (PDS) raw Experiment Data Records (EDRs) and calibrated Reduced Data Records (RDRs) into the native ISIS3 cube format. The ISIS camera models allow for orthorectification of the Vesta FC and VIR cubes to a variety of cartographic map projections using the long-standing "cam2map" application. Other standard tools such as "qview" for visualization and photometric processing applications (e.g.,"photomet" and "phocube") are available for use because of the integration of the new readers and camera models into ISIS [3]. These tools for Dawn cartographic and scientific analysis of Dawn data will be available for download in the October 2011 release of ISIS. The software release is timely as the Dawn image EDR data will be publicly released to the science community by the PDS within 90 days after each acquisition phase. Therefore, raw Vesta approach images will be available in November 2011. Raw images for other acquisition phases including survey, high altitude (HAMO) and low altitude (LAMO) mapping orbits will be delivered throughout 2012 [4]. Currently, there are no plans to include radiometric processing software for FC or VIR into ISIS. However, radiometrically calibrated PDS images (RDRs) will be publicly released six months after Vesta departure. [1] Russell, C.T., et al. (2007) Exploring the asteroid belt with ion propulsion: Dawn mission history, status and plans, Advances in Space Research, Volume 40, Issue 2, pages 193-201. [2] Anderson, J

  9. Infrared hyperspectral tunable filter imaging spectrometer for remote leak detection, chemical speciation, and stack/vent analysis applications

    Science.gov (United States)

    Hinnrichs, Michele

    2002-02-01

    With support from the Department of Energy, the State of California and the Gas Technology Institute, Pacific Advanced Technology is developing a small field portable infrared imaging spectrometer (Sherlock) based on the advances in hyperspectral tunable filter technology, that will be applied to the detection of fugitive gas leaks. This imaging spectrometer uses the Image Multi-spectral Sensing (IMSS) diffractive optic tunable filter invented by Pacific Advanced Technology . The Sherlock has an embedded digital signal processor for real time detection of the gas leak while surrounded by severe background noise. The infrared sensor engine is a 256 x 320 midwave cooled focal plane array which spans the spectral range from 3 to 5 microns, ideal for most hydrocarbon leaks. The technology is by no means limited to this spectral region, and can just as easily work in the longwave infrared from 8 to 12 microns for chemical detection applications. This paper will present the design of the Sherlock camera as well as processed data collected at a gas processing plant and an instrumented kiln at LSU using the prototype camera. The processed data shows that the IMSS imaging spectrometer, using an all passive approach, has the sensitivity to detect methane gas leaks at short range with a flow rate as low as 0.01 scfm2. In addition, the IMSS imaging spectrometer can measure hot gas plumes at longer ranges. As will be shown in this paper the IMSS can detect and image warm species gas additives of methane and propane in the Kiln exhaust stack. The methane injected gas with a concentration of 72 ppm and the propane with a concentration of 49 ppm (as seen by the IMSS sensor) at a range of 60 meters. The atmospheric path was a stressing environment, being hot and humid, for any imaging infrared spectrometer.

  10. Double beam near-infrared spectrometer for compensation of background water absorption and instrumental drift in intensity

    Institute of Scientific and Technical Information of China (English)

    CHANG Min; PENG Dan; XU Ke-xin

    2007-01-01

    A double beam near-infrared spectrometer is developed to compensate the water absorption and instrumental drift in intensity. The spectrometer maybe used for both single and double beam measurements, and the two operation modes are compared. The results show that the double beam technique eliminates instrumental drift in the single beam measurement and therefore the stability of the system increases by more than 20%. The compensation of the double beam system on water absorption is verified by the measurement of fat content in milk. The results show that the spectrum data based on double beam mode get better calibration model and lower prediction error than traditional single beam mode.

  11. Infrared ion spectroscopy in a modified quadrupole ion trap mass spectrometer at the FELIX free electron laser laboratory

    Science.gov (United States)

    Martens, Jonathan; Berden, Giel; Gebhardt, Christoph R.; Oomens, Jos

    2016-10-01

    We report on modifications made to a Paul-type quadrupole ion trap mass spectrometer and discuss its application in infrared ion spectroscopy experiments. Main modifications involve optical access to the trapped ions and hardware and software coupling to a variety of infrared laser sources at the FELIX infrared free electron laser laboratory. In comparison to previously described infrared ion spectroscopy experiments at the FELIX laboratory, we find significant improvements in efficiency and sensitivity. Effects of the trapping conditions of the ions on the IR multiple photon dissociation spectra are explored. Enhanced photo-dissociation is found at lower pressures in the ion trap. Spectra obtained under reduced pressure conditions are found to more closely mimic those obtained in the high-vacuum conditions of an Fourier transform ion cyclotron resonance mass spectrometer. A gas-mixing system is described enabling the controlled addition of a secondary gas into helium buffer gas flowing into the trap and allows for ion/molecule reactions in the trap. The electron transfer dissociation (ETD) option of the mass spectrometer allows for IR structure characterization of ETD-generated peptide dissociation products.

  12. Chromatic aberration short-wave infrared spectroscopy: nanoparticle spectra without a spectrometer.

    Science.gov (United States)

    Streit, Jason K; Bachilo, Sergei M; Weisman, R Bruce

    2013-02-05

    A new method is described for measuring the short-wave infrared (SWIR) emission wavelengths of numerous individual nanoparticles without using a dedicated spectrometer. Microscope objectives designed for use at visible wavelengths often show severe axial chromatic aberration in the SWIR. This makes coplanar objects emitting at different SWIR wavelengths appear to focus at different depths. After this aberration has been calibrated for a particular objective lens, the depth at which an emissive nanoparticle appears brightest and best focused can be used to deduce its peak emission wavelength. The method is demonstrated using a dilute, structurally polydisperse sample of single-walled carbon nanotubes deposited onto a microscope slide. Discrete emission centers in this sample have different peak wavelengths corresponding to specific nanotube structural species. A set of images was recorded at stepped focus settings and analyzed to find the sharpest focus depth of each nanotube. The chromatic aberration calibration curve converted these depths into peak emission wavelengths with a spectral resolution better than 3 nm, allowing identification of each nanotube's structure. Chromatic aberration spectroscopy is a practical tool for using existing microscopic equipment to extract significant spectral information on coplanar nanoparticle samples that emit or scatter light.

  13. Analysis of Index Gases of Coal Spontaneous Combustion Using Fourier Transform Infrared Spectrometer

    Directory of Open Access Journals (Sweden)

    Xiaojun Tang

    2014-01-01

    Full Text Available Analysis of the index gases of coal for the prevention of spontaneous combustion is of great importance for the enhancement of coal mine safety. In this work, Fourier Transform Infrared Spectrometer (FTIRS is presented to be used to analyze the index gases of coal in real time to monitor spontaneous combustion conditions. Both the instrument parameters and the analysis method are introduced at first by combining characteristics of the absorption spectra of the target analyte with the analysis requirements. Next, more than ten sets of the gas mixture containing ten components (CH4, C2H6, C3H8, iso-C4H10, n-C4H10, C2H4, C3H6, C2H2, CO, and CO2 are included and analyzed with a Spectrum Two FTIRS made by Perkin Elmer. The testing results show that the detection limit of most analytes is less than 2×10-6. All the detection limits meet the monitoring requirements of coal spontaneous combustion in China, which means that FTIRS may be an ideal instrument and the analysis method used in this paper is sufficient for spontaneous combustion gas monitoring on-line and even in situ, since FTIRS has many advantages such as fast analysis, being maintenance-free, and good safety.

  14. A lightweight near-infrared spectrometer for the detection of trace atmospheric species.

    Science.gov (United States)

    Gardiner, T; Mead, M I; Garcelon, S; Robinson, R; Swann, N; Hansford, G M; Woods, P T; Jones, R L

    2010-08-01

    This paper describes the development and deployment of a lightweight in situ near-infrared tunable diode laser absorption spectrometer (TDLAS) for balloon-borne measurements of trace species such as methane in the upper troposphere and stratosphere. The key feature of the instrument design is its ability to provide high sensitivity measurements with better than 1 part in 10(6) Hz(-1/2) optical sensitivity in a lightweight package weighing as little as 6 kg, and maintaining this level of performance over the wide range of conditions experienced during field measurements. The absolute accuracy for methane measurements is approximately 10% limited by uncertainties in determining the gas temperature in the measurement volume. The high sensitivity and high temporal resolution (2.3 s measurement period) enables details of the fine-scale structure in the atmosphere to be measured. The TDLAS instrument has been used on a number of major international measurement campaigns. Intercomparison with other instruments during these campaigns have confirmed the comparability of the results from this instrument with measurements made by a range of other techniques, and demonstrated the instruments suitability for studies of atmospheric dynamics, transport, and mixing processes.

  15. Reproducible quantification of ethanol in gasoline via a customized mobile near-infrared spectrometer.

    Science.gov (United States)

    Lutz, Oliver M D; Bonn, Günther K; Rode, Bernd M; Huck, Christian W

    2014-05-15

    This work describes the modification of an InGaAs diode array detector equipped miniaturized near-infrared (NIR) spectrometer enabling the reliable quantification of ethanol blended gasoline. A transflectance measurement cell is presented, utilizing a thermoelectric cooling (TEC) appliance ensuring thermostatic measurement conditions and a gold-coated spherical mirror as a reflector superior to conventional Spectralon(®). In total, four measurement modes (Spectralon(®) reflector, gold reflector and either reflectors with employed TEC) are discussed, enabling a straightforward comparison of the results. The test-set validated multivariate partial least squares regression (PLSR) model of the measurement mode involving both gold mirror and TEC yielded an Rval(2) value of 0.997, a limit of detection (LOD) of 0.68% w/w, a limit of quantification (LOQ) of 2.04% w/w, a standard error of prediction (SEP) of 0.21% w/w and a ratio performance deviation (RPD) of 15.2 while utilizing a single latent variable (LV). The NIR band assignment in this work has been established by employing the vibrational self-consistent field second order perturbative treatment (PT2-VSCF) and the computationally derived absorption maxima are compared to the experimentally observed data.

  16. A prototype stationary Fourier transform spectrometer for near-infrared absorption spectroscopy.

    Science.gov (United States)

    Li, Jinyang; Lu, Dan-feng; Qi, Zhi-mei

    2015-09-01

    A prototype stationary Fourier transform spectrometer (FTS) was constructed with a fiber-coupled lithium niobate (LiNbO3) waveguide Mach-Zehnder interferometer (MZI) for the purpose of rapid on-site spectroscopy of biological and chemical measurands. The MZI contains push-pull electrodes for electro-optic modulation, and its interferogram as a plot of intensity against voltage was obtained by scanning the modulating voltage from -60 to +60 V in 50 ms. The power spectrum of input signal was retrieved by Fourier transform processing of the interferogram combined with the wavelength dispersion of half-wave voltage determined for the MZI used. The prototype FTS operates in the single-mode wavelength range from 1200 to 1700 nm and allows for reproducible spectroscopy. A linear concentration dependence of the absorbance at λmax = 1451 nm for water in ethanolic solution was obtained using the prototype FTS. The near-infrared spectroscopy of solid samples was also implemented, and the different spectra obtained with different materials evidenced the chemical recognition capability of the prototype FTS. To make this prototype FTS practically applicable, work on improving its spectral resolution by increasing the maximum optical path length difference is in progress.

  17. Spectral analysis of Ahuna Mons from Dawn mission's visible-infrared spectrometer

    Science.gov (United States)

    Zambon, F.; Raponi, A.; Tosi, F.; De Sanctis, M. C.; McFadden, L. A.; Carrozzo, F. G.; Longobardo, A.; Ciarniello, M.; Krohn, K.; Stephan, K.; Palomba, E.; Pieters, C. M.; Ammannito, E.; Russell, C. T.; Raymond, C. A.

    2017-01-01

    Ahuna Mons is the highest mountain on Ceres. A unique complex in terms of size, shape, and morphology, Ahuna is bordered by flanks of the talus around its summit. Recent work by Ruesch et al. based on Dawn's Framing Camera images shed light on the possible origin of Ahuna Mons. According to Ruesch et al. (2016), Ahuna Mons is formed by a volcanic process involving the ascent of cryomagma and extrusion onto the surface followed by dome development and subsequent spreading. Here we analyzed in detail the composition of Ahuna Mons, using data acquired by the visible and infrared spectrometer aboard Dawn. The spectral analysis reveals a relatively high abundance of carbonates and a nonhomogeneous variation in carbonate composition and abundance along Ahuna's flanks, associated with a lower amount of the Ceres's ubiquitous NH4-phyllosilicates over a large portion of the flanks. The grain size is coarser on the flanks than in the surrounding regions, suggesting the presence of fresher material, also compatible with a larger abundance of carbonates. Thermal variations are seen in Ahuna, supporting the evidence of different compactness of the surface regolith in specific locations. Results of the spectral analysis are consistent with a possible cryovolcanic origin which exposed fresher material that slid down on the flanks.

  18. Infrared limb sounding of Titan with the Cassini Composite InfraRed Spectrometer: effects of the mid-IR detector spatial responses.

    Science.gov (United States)

    Nixon, Conor A; Teanby, Nicholas A; Calcutt, Simon B; Aslam, Shahid; Jennings, Donald E; Kunde, Virgil G; Flasar, F Michael; Irwin, Patrick G; Taylor, Fredric W; Glenar, David A; Smith, Michael D

    2009-04-01

    The composite infrared spectrometer (CIRS) instrument on board the Cassini Saturn orbiter employs two 1x10 HgCdTe detector arrays for mid-infrared remote sensing of Titan's and Saturn's atmospheres. In this paper we show that the real detector spatial response functions, as measured in ground testing before launch, differ significantly from idealized "boxcar" responses. We further show that neglecting this true spatial response function when modeling CIRS spectra can have a significant effect on interpretation of the data, especially in limb-sounding mode, which is frequently used for Titan science. This result has implications not just for CIRS data analysis but for other similar instrumental applications.

  19. TOTAL COLUMN METHANE RETRIEVALS USING THE TROPOSPHERIC INFRARED MAPPING SPECTROMETER OVER SUNGLINT

    Directory of Open Access Journals (Sweden)

    N. Larsen

    2012-07-01

    Full Text Available Because it is a greenhouse gas, the detection of methane concentrations is a global issue. Additionally, the presence of methane is indicative of potential valuable petroleum and natural gas deposits. Therefore methane seep detection is useful for petroleum exploration around the world. The detection of methane, and other absorbing gases, over water is an issue for passive systems because one is seeking to detect an absorbing gas over an absorbing surface. The solution to this dilemma is to use the sun/sensor geometry for sun glint off of water to measure the absorbing gas over a reflecting surface, and therefore significantly increase the signal to noise of the measurement being taken. In September of 2010 Lockheed Martin performed a proof of concept by demonstrating from an airship over San Francisco Bay the capability of the Tropospheric Infrared Mapping Spectrometer's (TIMS hyper spectral sensor to passively measure methane, CO, and water vapor over sunglint water. The Lockheed Martin prototype TIMS sensor system is a hyper spectral grating spectrometer instrument that operates in the 2.3 micron spectral region at 0.25 cm-1 resolution. The Lockheed Martin retrieval algorithm developed applies the kCARTA (kCompressed Atmospheric Radiative Transfer Algorithm with Jacobians, with the HITRAN 2008 lineshape parameters, to retrieve the total column amount of atmospheric species along with the calibrated TIMS sensors radiometric input. A cell with known amount of methane was placed into the input to the TIMS to simulate atmospheric enhancements near the water surface. The amount in the cell was retrieved well within the uncertainty of 1% of the amount in the cell. Multi frame retrievals on data in which the cell was not placed into the input beam demonstrated 1% precision. In addition, in situ surface measurements were done over a landfill park, where measurements of methane were taken over known hotspots. This research allows for the future

  20. Correlation spectrometer

    Science.gov (United States)

    Sinclair, Michael B.; Pfeifer, Kent B.; Flemming, Jeb H.; Jones, Gary D.; Tigges, Chris P.

    2010-04-13

    A correlation spectrometer can detect a large number of gaseous compounds, or chemical species, with a species-specific mask wheel. In this mode, the spectrometer is optimized for the direct measurement of individual target compounds. Additionally, the spectrometer can measure the transmission spectrum from a given sample of gas. In this mode, infrared light is passed through a gas sample and the infrared transmission signature of the gasses present is recorded and measured using Hadamard encoding techniques. The spectrometer can detect the transmission or emission spectra in any system where multiple species are present in a generally known volume.

  1. FAR-INFRARED LINE SPECTRA OF SEYFERT GALAXIES FROM THE HERSCHEL-PACS SPECTROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Spinoglio, Luigi; Pereira-Santaella, Miguel; Busquet, Gemma [Istituto di Astrofisica e Planetologia Spaziali, INAF, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Dasyra, Kalliopi M. [Observatoire de Paris, LERMA (CNRS:UMR8112), 61 Av. de l' Observatoire, F-75014, Paris (France); Calzoletti, Luca [Agenzia Spaziale Italiana (ASI) Science Data Center, I-00044 Frascati (Roma) (Italy); Malkan, Matthew A. [Astronomy Division, University of California, Los Angeles, CA 90095-1547 (United States); Tommasin, Silvia, E-mail: luigi.spinoglio@iaps.inaf.it [Weizmann Institute of Science, Department of Neurobiology, Rehovot 76100 (Israel)

    2015-01-20

    We observed the far-IR fine-structure lines of 26 Seyfert galaxies with the Herschel-PACS spectrometer. These observations are complemented with Spitzer Infrared Spectrograph and Herschel SPIRE spectroscopy. We used the ionic lines to determine electron densities in the ionized gas and the [C I] lines, observed with SPIRE, to measure the neutral gas densities, while the [O I] lines measure the gas temperature, at densities below ∼10{sup 4} cm{sup –3}. Using the [O I]145 μm/63 μm and [S III]33/18 μm line ratios, we find an anti-correlation of the temperature with the gas density. Various fine-structure line ratios show density stratifications in these active galaxies. On average, electron densities increase with the ionization potential of the ions. The infrared lines arise partly in the narrow line region, photoionized by the active galactic nucleus (AGN), partly in H II regions photoionized by hot stars, and partly in photo-dissociated regions. We attempt to separate the contributions to the line emission produced in these different regions by comparing our observed emission line ratios to theoretical values. In particular, we tried to separate the contribution of AGNs and star formation by using a combination of Spitzer and Herschel lines, and we found that besides the well-known mid-IR line ratios, the line ratio of [O III]88 μm/[O IV]26 μm can reliably discriminate the two emission regions, while the far-IR line ratio of [C II]157 μm/[O I]63 μm is only able to mildly separate the two regimes. By comparing the observed [C II]157 μm/[N II]205 μm ratio with photoionization models, we also found that most of the [C II] emission in the galaxies we examined is due to photodissociation regions.

  2. Current instrument status of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

    Science.gov (United States)

    Eastwood, Michael L.; Sarture, Charles M.; Chrien, Thomas G.; Green, Robert O.; Porter, Wallace M.

    1991-01-01

    An upgraded version of AVIRIS, an airborne imaging spectrometer based on a whiskbroom-type scanner coupled via optical fibers to four dispersive spectrometers, that has been in operation since 1987 is described. Emphasis is placed on specific AVIRIS subsystems including foreoptics, fiber optics, and an in-flight reference source; spectrometers and detector dewars; a scan drive mechanism; a signal chain; digital electronics; a tape recorder; calibration systems; and ground support requirements.

  3. Compact High-Resolution Broad-Band Terahertz Fabry-Perot Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our objective is to develop a compact scanning Fabry-Perot spectrometer, for satellite far-infrared astronomy and Earth remote sensing, that operates at wavelengths...

  4. Spectral calibration for deriving surface mineralogy of Asteroid (25143) Itokawa from Hayabusa Near-Infrared Spectrometer (NIRS) Data

    CERN Document Server

    Bhatt, Megha; Corre, Lucille Le; Sanchez, Juan A; Dunn, Tasha; Izawa, Matthew R M; Li, Jian-Yang; Becker, Kris J; Weller, Lynn

    2015-01-01

    We present spectral calibration equations for determining mafic silicate composition of near-Earth asteroid (25143) Itokawa from visible/near-infrared spectra measured using the Near Infrared Spectrometer (NIRS), on board the Japanese Hayabusa spacecraft. Itokawa was the target of the Hayabusa sample return mission and has a surface composition similar to LL-type ordinary chondrites. Existing laboratory spectral calibrations use a spectral wavelength range that is wider (0.75-2.5 microns) than that of the NIRS instrument (0.85-2.1 microns) making them unfit for interpreting the Hayabusa spectral data currently archived in the Planetary Data System. We used laboratory measured near-infrared reflectance spectra of ordinary (H, L and LL) chondrites from the study of Dunn et al. (2010), which we resampled to the NIRS wavelength range. Using spectral parameters extracted from these resampled spectra we established a relationship between band parameters and their mafic silicate composition (olivine and low-Ca pyrox...

  5. Measurements of ozone columns in different atmospheric layers over St. Petersburg (Russia) using ground-based FTIR spectrometer in comparison with IASI satellite data

    Science.gov (United States)

    Virolainen, Yana; Eremenko, Maxim; Timofeyev, Yury; Dufour, Gaelle; Poberovsky, Anatoly; Polyakov, Alexander; Imhasin, Hamud

    2014-05-01

    Ozone plays a key role in the photochemical equilibrium of the atmosphere. In the stratosphere, it absorbs harmful ultraviolet solar radiation, in the troposphere it is one of the main air pollutant, greenhouse gases and it is involved in the troposphere's oxidative capacity. In this study, we analyze the ozone variability in different atmospheric layers over St. Petersburg (Russia) measured with the ground-based FTIR spectrometer Bruker 125 HR at the Peterhof station (59.82 N, 29.88 E), and compare it to the satellite Infrared Atmospheric Sounding Interferometer (IASI) ozone retrievals. The FTIR spectrometer has a maximum optical path difference of 180 cm, yielding an apodized spectral resolution of 0.008 cm-1, and has been recording IR spectra since 2009. The high spectral resolution of the registered spectra allows the retrieval of the ozone content in four atmospheric layers. We applied the PROFFIT inversion code to the ozone vertical profiles retrievals in 9.6-µm O3 absorption band and calculated the daily means of ozone partial columns for about 300 days between 2009 and 2013. The IASI instrument onboard the satellite MetOp-A measures the thermal infrared radiation emitted by the Earth's surface and the atmosphere with an apodized spectral resolution of 0.5 cm-1. We used the LISA (Laboratoire Inter-universitaire des Systemes Atmospheriques) retrieval algorithm for deriving the ozone profiles between 0 and 60 km for the region of 2 degrees around the Peterhof station in coincidence with FTIR-observation dates, and averaged profiles daily over all the pixels in the considered region. In this study, we compare and discuss the both types of ozone retrievals: total and partial columns in four atmospheric layers (0-12 km, 12-18 km, 18-25 km, and 25-60 km) for 285 coincident days in 2009-2013. This study was partly supported by Saint-Petersburg State University (project No. 11.0.44.2010) and Russian Foundation for Basic Research (grants No. 12-05-00596, 12

  6. 傅里叶变换红外成像光谱仪非均匀性在线定标与校正研究%Study on Nonuniformity Online Calibration and Correction of Fourier Transform Infrared Imaging Spectrometer

    Institute of Scientific and Technical Information of China (English)

    殷世民; 应小凡; 陈洪波; 陈真诚; 相里斌

    2014-01-01

    Due to the particular structure of Fourier transform infrared imaging spectrometer, its nonuniformity online calibration and correction is always a technical problem that has not been solved in engineering. Based on brief review to the principle and algorithm of nonuniformity correction of IRFPA, through in-depth analysis of principle and structure of time modulation, space modulation type and time and space combined modulation type Fourier transform infrared imaging spectrometer, it is given that online method for non-uniformity calibration and correction of three types of Fourier transform infrared imaging spectrometer, which should establish a good technical foundation to on-orbit nonuniformity calibration and correction for Fourier transform infrared imaging spectrometer on satellite.%由于傅里叶变换红外成像光谱仪结构的特殊性,其非均匀性在线定标与校正在工程上一直没有得到有效解决。首先对IRFPA非均匀性校正的原理与算法进行了简要阐述,在此基础上,通过对时间调制型、空间调制型及时间空间联合调制型傅里叶变换红外成像光谱仪原理结构的深入分析,针对这三种制式的光谱仪,分别研究出了相应的非均匀性在线定标与校正的方法,为星载傅里叶变换红外成像光谱仪非均匀性的在轨定标奠定了良好的技术基础。

  7. The effect of lunarlike satellites on the orbital infrared light curves of Earth-analog planets.

    Science.gov (United States)

    Moskovitz, Nicholas A; Gaidos, Eric; Williams, Darren M

    2009-04-01

    We have investigated the influence of lunarlike satellites on the infrared orbital light curves of Earth-analog extrasolar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet and determine its orbit. We used an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon, and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of Earth, while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g., via spectroscopy or visible-wavelength detection of specular glint from a surface ocean), only the largest (approximately Mars-sized) lunarlike satellites can be detected by light curve data from a TPF-like instrument (i.e., one that achieves a photometric signal-to-noise ratio of 10 to 20 at infrared wavelengths). Nondetection of a lunarlike satellite can obfuscate the interpretation of a given system's infrared light curve so that it may resemble a single planet with high obliquity, different orbital longitude of vernal equinox relative to inferior conjunction, and in some cases drastically different thermal characteristics. If the thermal properties of the planet are not independently established, then the presence of a lunarlike satellite cannot be inferred from infrared data, which would thus demonstrate that photometric light curves alone can only be used for preliminary study, and the addition of spectroscopic data will be necessary.

  8. DLP NIRscan Nano: an ultra-mobile DLP-based near-infrared Bluetooth spectrometer

    Science.gov (United States)

    Gelabert, Pedro; Pruett, Eric; Perrella, Gavin; Subramanian, Sreeram; Lakshminarayanan, Aravind

    2016-02-01

    The DLP NIRscan Nano is an ultra-portable spectrometer evaluation module utilizing DLP technology to meet lower cost, smaller size, and higher performance than traditional architectures. The replacement of a linear array detector with DLP digital micromirror device (DMD) in conjunction with a single point detector adds the functionality of programmable spectral filters and sampling techniques that were not previously available on NIR spectrometers. This paper presents the hardware, software, and optical systems of the DLP NIRscan Nano and its design considerations on the implementation of a DLP-based spectrometer.

  9. Coherent-radiation spectroscopy of few-femtosecond electron bunches using a middle-infrared prism spectrometer.

    Science.gov (United States)

    Maxwell, T J; Behrens, C; Ding, Y; Fisher, A S; Frisch, J; Huang, Z; Loos, H

    2013-11-01

    Modern, high-brightness electron beams such as those from plasma wakefield accelerators and free-electron laser linacs continue the drive to ever-shorter bunch durations. In low-charge operation (~20 pC), bunches shorter than 10 fs are reported at the Linac Coherent Light Source (LCLS). Though suffering from a loss of phase information, spectral diagnostics remain appealing as compact, low-cost bunch duration monitors suitable for deployment in beam dynamics studies and operations instrumentation. Progress in middle-infrared (MIR) imaging has led to the development of a single-shot, MIR prism spectrometer to characterize the corresponding LCLS coherent beam radiation power spectrum for few-femtosecond scale bunch length monitoring. In this Letter, we report on the spectrometer installation as well as the temporal reconstruction of 3 to 60 fs-long LCLS electron bunch profiles using single-shot coherent transition radiation spectra.

  10. Coherent-Radiation Spectroscopy of Few-Femtosecond Electron Bunches Using a Middle-Infrared Prism Spectrometer

    Science.gov (United States)

    Maxwell, T. J.; Behrens, C.; Ding, Y.; Fisher, A. S.; Frisch, J.; Huang, Z.; Loos, H.

    2013-11-01

    Modern, high-brightness electron beams such as those from plasma wakefield accelerators and free-electron laser linacs continue the drive to ever-shorter bunch durations. In low-charge operation (˜20pC), bunches shorter than 10 fs are reported at the Linac Coherent Light Source (LCLS). Though suffering from a loss of phase information, spectral diagnostics remain appealing as compact, low-cost bunch duration monitors suitable for deployment in beam dynamics studies and operations instrumentation. Progress in middle-infrared (MIR) imaging has led to the development of a single-shot, MIR prism spectrometer to characterize the corresponding LCLS coherent beam radiation power spectrum for few-femtosecond scale bunch length monitoring. In this Letter, we report on the spectrometer installation as well as the temporal reconstruction of 3 to 60 fs-long LCLS electron bunch profiles using single-shot coherent transition radiation spectra.

  11. Ultrasensitive Mid-Infrared In Situ Spectrometer for Planetary Atmospheric Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Small Business Innovative Research Phase I proposal seeks to develop a compact, robust in situ spectrometer capable of detecting multiple gas-phase species in...

  12. Ultrasensitive Mid-Infrared In Situ Spectrometer for Planetary Atmospheric Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Small Business Innovative Research Phase I proposal seeks to develop a compact, robust in situ spectrometer capable of detecting multiple gas-phase species in...

  13. Calibration and modelling of the SODART-OXS Bragg spectrometer onboard the SRG satellite

    DEFF Research Database (Denmark)

    Halm, Ingolf; Wiebicke, Hans-Joachim; Christensen, Finn Erland

    1998-01-01

    The SODART X-ray telescope includes an Objective Crystal Spectrometer (OXS) providing a high energy resolving power by Bragg reflection upon crystals. To cover a wide energy range, 3 types of natural crystals (LiF, Si, RAP) and a Co/C multilayer structure upon Si are used in the ranges 5-11 keV, ...

  14. The objective crystal spectrometer OXS on the spectrum-X-gamma satellite crystal calibrations

    DEFF Research Database (Denmark)

    Abdali, S.; Christensen, Finn Erland; Schnopper, H.W.;

    1997-01-01

    The four kinds of crystals; RAP(001), Si(111), LiF(220) and the Co/C multilayer on the super polished Si(111) crystals, together make up the objective crystal spectrometer OXS. They cover a wide energy range extending from 0.16 eV to 8 keV. A study of crystal reflectivity and energy resolution...

  15. Application of satellite infrared measurements to mapping sea ice

    Science.gov (United States)

    Barnes, J. C.

    1972-01-01

    The application of the ITOS-SR (scanning radiometer) infrared measurements for mapping sea ice was examined. The work included detailed mapping of ice features visible in the ITOS nighttime DRSR (direct readout scanning radiometer) pictorial data and in Nimbus summertime film strip data. Analyses of digital temperature values from computer printouts of ITOS stored data and from Nimbus data listings were also undertaken, and densitometric measurements of both ITOS and Nimbus data were initiated.

  16. Identifying clouds over the Pierre Auger Observatory using infrared satellite data

    NARCIS (Netherlands)

    Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anticic, T.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Baughman, B.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Belletoile, A.; Bellidol, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; De La Vega, G.; de Mello, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Diaz, J. C.; Diaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; San Luis, P. Facal; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Fliescher, S.; Fox, B. D.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Froehlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garcia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glaser, C.; Glass, H.; Golup, G.; Gomez Albarracin, F.; Gomez Berisso, M.; Gomez Vitale, P. F.; Goncalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Horandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Krause, R.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Agueera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Masias Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Micanovic, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Mirarrionti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Mueller, G.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, T. J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Niggemann, T.; Nitz, D.; Nosek, D.; Nozka, L.; Oehlschlaeger, J.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Pfendner, C.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Ponce, V. H.; Pontz, M.; Porcelli, A.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Fernandez, G. Rodriguez; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Ruehle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Greus, F. Salesa; Salina, G.; Sanchez, F.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovanek, P.; Schroeder, F. G.; Schulz, J.; Schuster, D.; Sciutto, Si.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Straub, M.; Stutz, A.; Suarez, F.; Suomijaervi, T.; Supanitsky, A. D.; Susa, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Tascau, O.; Tcaciuc, R.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Machado, D. Torres; Travnicek, P.; Tridapalli, D. B.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano Garcia, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Martin, L.

    2013-01-01

    We describe a new method of identifying night-time clouds over the Pierre Auger Observatory using infrared data from the Imager instruments on the GOES-12 and GOES-13 satellites. We compare cloud. identifications resulting from our method to those obtained by the Central Laser Facility of the Auger

  17. On-Chip Micro-Electro-Mechanical System Fourier Transform Infrared (MEMS FT-IR) Spectrometer-Based Gas Sensing.

    Science.gov (United States)

    Erfan, Mazen; Sabry, Yasser M; Sakr, Mohammad; Mortada, Bassem; Medhat, Mostafa; Khalil, Diaa

    2016-05-01

    In this work, we study the detection of acetylene (C2H2), carbon dioxide (CO2) and water vapor (H2O) gases in the near-infrared (NIR) range using an on-chip silicon micro-electro-mechanical system (MEMS) Fourier transform infrared (FT-IR) spectrometer in the wavelength range 1300-2500 nm (4000-7692 cm(-1)). The spectrometer core engine is a scanning Michelson interferometer micro-fabricated using a deep-etching technology producing self-aligned components. The light is free-space propagating in-plane with respect to the silicon chip substrate. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator corresponding to about 30 cm(-1) resolution. Multi-mode optical fibers are used to connect light between the wideband light source, the interferometer, the 10 cm gas cell, and the optical detector. A wide dynamic range of gas concentration down to 2000 parts per million (ppm) in only 10 cm length gas cell is demonstrated. Extending the wavelength range to the mid-infrared (MIR) range up to 4200 nm (2380 cm(-1)) is also experimentally demonstrated, for the first time, using a bulk micro-machined on-chip MEMS FT-IR spectrometer. The obtained results open the door for an on-chip optical gas sensor for many applications including environmental sensing and industrial process control in the NIR/MIR spectral ranges.

  18. Estimation of volcanic ash refractive index from satellite infrared sounder data

    Science.gov (United States)

    Ishimoto, H.; Masuda, K.

    2014-12-01

    The properties of volcanic ash clouds (cloud height, optical depth, and effective radius of the particles) are planned to estimate from the data of the next Japanese geostationary meteorological satellite, Himawari 8/9. The volcanic ash algorithms, such as those proposed by NOAA/NESDIS and by EUMETSAT, are based on the infrared absorption properties of the ash particles, and the refractive index of a typical volcanic rock (i.e. andesite) has been used in the forward radiative transfer calculations. Because of a variety of the absorption properties for real volcanic ash particles at infrared wavelengths (9-13 micron), a large retrieval error may occur if the refractive index of the observed ash particles was different from that assumed in the retrieval algorithm. Satellite infrared sounder provides spectral information for the volcanic ash clouds. If we can estimate the refractive index of the ash particles from the infrared sounder data, a dataset of the optical properties for similar rock type of the volcanic ash can be prepared for the ash retrieval algorithms of geostationary/polar-orbiting satellites in advance. Furthermore, the estimated refractive index can be used for a diagnostic and a correction of the ash particle model in the retrieval algorithm within a period of the volcanic activities. In this work, optimal estimation of the volcanic ash parameters was conducted through the radiative transfer calculations for the window channels of the atmospheric infrared sounder (AIRS). The estimated refractive indices are proposed for the volcanic ash particles of some eruption events.

  19. Infrared heterodyne spectrometer measurements of vertical profile of tropospheric ammonia and ozone. [using dual carbon dioxide laser

    Science.gov (United States)

    Peyton, B. J.; Lange, R. A.; Savage, M. G.; Seals, R. K.; Allario, F.

    1977-01-01

    Remote sensing of the concentration and vertical distribution of atmospheric gases has been carried out using a dual CO2 laser multichannel infrared heterodyne spectrometer (IHS). The high specificity and nearly quantum-noise-limited sensitivity of the IHS provide the capability of scanning individual signature lines of selected atmospheric constituents in the 9 to 11 micron region. A comprehensive investigation of the spectral overlap between CO2 laser local oscillator transitions and selected atmospheric constituents was performed; measurements of the atmospheric absorption of solar radiation from the ground were carried out at selected laser transitions for ammonia and ozone.

  20. Geometric and radiometric preprocessing of airborne visible/infrared imaging spectrometer (AVIRIS) data in rugged terrain for quantitative data analysis

    Science.gov (United States)

    Meyer, Peter; Green, Robert O.; Staenz, Karl; Itten, Klaus I.

    1994-01-01

    A geocoding procedure for remotely sensed data of airborne systems in rugged terrain is affected by several factors: buffeting of the aircraft by turbulence, variations in ground speed, changes in altitude, attitude variations, and surface topography. The current investigation was carried out with an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) scene of central Switzerland (Rigi) from NASA's Multi Aircraft Campaign (MAC) in Europe (1991). The parametric approach reconstructs for every pixel the observation geometry based on the flight line, aircraft attitude, and surface topography. To utilize the data for analysis of materials on the surface, the AVIRIS data are corrected to apparent reflectance using algorithms based on MODTRAN (moderate resolution transfer code).

  1. Geometric and radiometric preprocessing of airborne visible/infrared imaging spectrometer (AVIRIS) data in rugged terrain for quantitative data analysis

    Science.gov (United States)

    Meyer, Peter; Green, Robert O.; Staenz, Karl; Itten, Klaus I.

    1994-01-01

    A geocoding procedure for remotely sensed data of airborne systems in rugged terrain is affected by several factors: buffeting of the aircraft by turbulence, variations in ground speed, changes in altitude, attitude variations, and surface topography. The current investigation was carried out with an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) scene of central Switzerland (Rigi) from NASA's Multi Aircraft Campaign (MAC) in Europe (1991). The parametric approach reconstructs for every pixel the observation geometry based on the flight line, aircraft attitude, and surface topography. To utilize the data for analysis of materials on the surface, the AVIRIS data are corrected to apparent reflectance using algorithms based on MODTRAN (moderate resolution transfer code).

  2. Validation strategy for satellite observations of tropospheric reactive gases

    Directory of Open Access Journals (Sweden)

    Andreas Richter

    2014-01-01

    Full Text Available Over the last twodecades, satellite observations of tropospheric composition have becomepossible using nadir viewing spectrometers operating in the UV, visible, nearinfrared, and thermal infrared spectral range. [...

  3. Science operations management. [with Infrared Astronomy Satellite project

    Science.gov (United States)

    Squibb, G. F.

    1984-01-01

    The operation teams engaged in the IR Astronomical Satellite (IRAS) project included scientists from the IRAS International Science Team. The detailed involvement of these scientists in the design, testing, validation, and operations phases of the IRAS mission contributed to the success of this project. The Project Management Group spent a substantial amount of time discussing science-related issues, because science team coleaders were members from the outset. A single scientific point-of-contact for the Management Group enhanced the depth and continuity of agreement reached in decision-making.

  4. Hydrated salt minerals on Europa's Surface from the Galileo near-infrared mapping spectrometer (NIMS) investigation

    Science.gov (United States)

    McCord, T.B.; Hansen, G.B.; Matson, D.L.; Johnson, T.V.; Crowley, J.K.; Fanale, F.P.; Carlson, R.W.; Smythe, W.D.; Martin, P.D.; Hibbitts, C.A.; Granahan, J.C.; Ocampo, A.

    1999-01-01

    We reported evidence of heavily hydrated salt minerals present over large areas of Europa's surface from analysis of reflectance spectra returned by the Galileo mission near infrared mapping spectrometer (NIMS) [McCord et al., 1997a, b, 1998a, b]. Here we elaborate on this earlier evidence, present spatial distributions of these minerals, examine alternate water-ice interpretations, expand on our hydrated-salts interpretation, consider salt mineral stability on Europa, and discuss the implications. Extensive well-defined areas on Europa show distinct, asymmetric water-related absorption bands in the 1 to 2.5-??m region. Radiative transfer modeling of water ice involving different particle sizes and layers at Europa temperatures does not reproduce the distinctive Europa water bands. However, ice near its melting temperature, such as in terrestrial environments, does have some characteristics of the Europa spectrum. Alternatively, some classes of heavily hydrated minerals do exhibit such water bands. Among plausible materials, heavily hydrated salt minerals, such as magnesium and sodium sulfates, sodium carbonate and their mixtures, are preferred. All Europa spectral features are present in some salt minerals and a very good match to the Europa spectrum can be achieved by mixing several salt spectra. However, no single or mix of salt mineral spectra from the limited library available has so far been found to perfectly match the Europa spectrum in every detail. The material is concentrated at the lineaments and in chaotic terrain, which are technically disrupted areas on the trailing side. Since the spectrum of the material on Europa is nearly the same everywhere so-far studied, the salt or salt-mixture composition may be nearly uniform. This suggests similar sources and processes over at least a near-hemispheric scale. This would suggest that an extensive subsurface ocean containing dissolved salts is the source, and several possible mechanisms for deposit

  5. A broadband ultrafast transient absorption spectrometer covering the range from near-infrared (NIR) down to green.

    Science.gov (United States)

    Schmidhammer, Uli; Jeunesse, Pierre; Stresing, Gerhard; Mostafavi, Mehran

    2014-01-01

    We present a new development for pump-probe absorption spectroscopy that allows the simultaneous measurement from the green part of the visible spectrum (510 nm) over the whole near-infrared range to >1600 nm, corresponding to 0.77-2.40 eV. The system is based on a sub-picosecond supercontinuum generated in bulk material used as a broadband probe that is dispersed with a custom-made prism spectrometer and detected by an InGaAs array with extended sensitivity to the visible. Two versions, with and without probe referencing, are implemented for operation at laser repetition rates of a few hertz and kilohertz, respectively. After presentation of the optical configuration of the spectrometer, its performance is characterized and further illustrated on two time scales, with the ultrafast radiolysis of isopropanol induced by a picosecond electron pulse and with the instantaneous response of a BK7 plate to a femtosecond light pulse. The photophysics of the dye IR-140 is resolved from the femto- to picosecond regime. Stable and easy day-to-day routine use of the spectrometer also can be achieved in non-optical laboratory surroundings. For operation in a hazardous environment, the optical probe beams can be transported to the detector unit by optical fibers.

  6. A review on the applications of portable near-infrared spectrometers in the agro-food industry.

    Science.gov (United States)

    dos Santos, Cláudia A Teixeira; Lopo, Miguel; Páscoa, Ricardo N M J; Lopes, João A

    2013-11-01

    Industry has created the need for a cost-effective and nondestructive quality-control analysis system. This requirement has increased interest in near-infrared (NIR) spectroscopy, leading to the development and marketing of handheld devices that enable new applications that can be implemented in situ. Portable NIR spectrometers are powerful instruments offering several advantages for nondestructive, online, or in situ analysis: small size, low cost, robustness, simplicity of analysis, sample user interface, portability, and ergonomic design. Several studies of on-site NIR applications are presented: characterization of internal and external parameters of fruits and vegetables; conservation state and fat content of meat and fish; distinguishing among and quality evaluation of beverages and dairy products; protein content of cereals; evaluation of grape ripeness in vineyards; and soil analysis. Chemometrics is an essential part of NIR spectroscopy manipulation because wavelength-dependent scattering effects, instrumental noise, ambient effects, and other sources of variability may complicate the spectra. As a consequence, it is difficult to assign specific absorption bands to specific functional groups. To achieve useful and meaningful results, multivariate statistical techniques (essentially involving regression techniques coupled with spectral preprocessing) are therefore required to extract the information hidden in the spectra. This work reviews the evolution of the use of portable near-infrared spectrometers in the agro-food industry.

  7. The Thermal Infrared Compact Imaging Spectrometer (TIRCIS): a follow-on to the Space Ultra Compact Hyperspectral Imager (SUCHI)

    Science.gov (United States)

    Crites, S. T.; Wright, R.; Lucey, P. G.; Chan, J.; Gabrieli, A.; Garbeil, H.; Horton, K. A.; Imai-Hong, A. K. R.; Pilger, E. J.; Wood, M.; Yoneshige, L.

    2015-05-01

    The Thermal Infrared Compact Imaging Spectrometer (TIRCIS) is a long wave infrared (LWIR, 8-14 microns) hyperspectral imager designed as the follow-on to the University of Hawaii's SUCHI (Space Ultra Compact Hyperspectral Imager). SUCHI is a low-mass (transform spectrometer with images collected by a commercial off-the-shelf microbolometer contained inside a 1-atm sealed vessel. The sensor has been fully integrated with the HiakaSat microsatellite and is awaiting launch in 2015. The TIRCIS instrument is based on the same principles but takes lessons learned from SUCHI and applies them to a new design with improvements in spatial resolution, spectral resolution and spectral responsivity. The TIRCIS instrument is based on an uncooled microbolometer array with custom detector coatings to enhance responsivity towards 7 microns. Like SUCHI, TIRCIS utilizes a variable-gap Fabry Perot interferometer to create the spectra, but three different interferometer wedges with varying slopes resulting in spectral resolution ranging from 44 cm-1 to 6.5 cm-1 will be tested to explore tradeoffs between spectral resolution and sensitivity. TIRCIS is designed to achieve 120 m spatial resolution, compared with 230 m for SUCHI, from a theoretical 500 km orbit. It will be used for ground and aircraft data collection but will undergo environmental testing to demonstrate its relevance to the space environment. TIRCIS has been fully designed and is entering fabrication, with an operational instrument to be delivered in October, 2015.

  8. Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer - Shuttle Pallet Satellite (ORFEUS-SPAS)

    Science.gov (United States)

    1993-01-01

    The objective of the ORFEUS mission is to launch a deployable/retrievable astronomical platform and obtain ultraviolet spectra for both astrophysically interesting sources and the intervening interstellar medium. Also, the IMAX cameras will obtain footage of both the Shuttle and the ORFEUS-SPAS satellite during the deployment/retrieval operations phase of the ORFEUS-SPAS mission.

  9. The mid-infrared instrument for the James Webb Space telescope, VI: the medium resolution spectrometer

    NARCIS (Netherlands)

    Wells, M.; Pel, J.W.; Glasse, A.; Wright, G.S.; Aitink-Kroes, G.; Azzollini, R.; Beard, S.; Brandl, B.R.; Gallie, A.; Geers, V.C.; Glauser, A.M.; Hastings, P.; Henning, T.; Jager, R.; Justtanont, K.; Kruizinga, B.; Lahuis, F.; Lee, D.; Martinez-Delgado, I.; Martínez-Galarza, J.R.; Meijers, M.; Morrison, J.E.; Müller, F.; Nakos, T.; O’Sullivan, B.; Oudenhuysen, A.; Parr-Burman, P.; Pauwels, E.; Rohloff, R.R.; Schmalzl, E.; Sykes, J.; Thelen, M.P.; Dishoeck, E.F. van; Vandenbussche, B.; Venema, L.B.; Visser, H.; Waters, L.B.F.M.; Wright, D.

    2015-01-01

    We describe the design and performance of the Medium Resolution Spectrometer (MRS) for the JWST-MIRI instrument. The MRS incorporates four coaxial spectral channels in a compact opto-mechanical layout that generates spectral images over fields of view up to 7.7 × 7.7″ in extent and at spectral resol

  10. The Mid-Infrared Instrument for the James Webb Space Telescope, VI: The Medium Resolution Spectrometer

    NARCIS (Netherlands)

    Wells, M.; Pel, J.-W.; Glasse, A.; Wright, G.S.; Aitink-Kroes, G.; Azzollini, R.; Beard, S.; Brandl, B.R.; Gallie, A.; Geers, V.C.; Glauser, A.M.; Hastings, P.; Henning, Th.; Jager, R.; Justtanont, K.; Kruizinga, B.; Lahuis, F.; Lee, D.; Martinez-Delgado, I.; Martínez-Galarza, J.R.; Meijers, M.; Morrison, J.E.; Müller, F.; Nakos, T.; O'Sullivan, B.; Oudenhuysen, A.; Parr-Burman, P.; Pauwels, E.; Rohloff, R.R.; Schmalzl, E.; Sykes, J.; Thelen, M.P.; van Dishoeck, E.F.; Vandenbussche, B.; Venema, L.B.; Visser, H.; Waters, L.B.F.M.; Wright, D.

    2015-01-01

    We describe the design and performance of the Medium Resolution Spectrometer (MRS) for the JWST-MIRI instrument. The MRS incorporates four coaxial spectral channels in a compact opto-mechanical layout that generates spectral images over fields of view up to 7.7 × 7.7'' in extent and at spectral reso

  11. Measurement of surface temperature and emissivity by a multitemperature method for Fourier-transform infrared spectrometers

    DEFF Research Database (Denmark)

    Clausen, Sønnik; Morgenstjerne, Axel; Rathmann, Ole

    1996-01-01

    Surface temperatures are estimated with high precision based on a multitemperature method for Fourier-transform spectrometers. The method is based on Planck's radiation law and a nonlinear least-squares fitting algorithm applied to two or more spectra at different sample temperatures and a single...

  12. Thermal infrared spectrometer for earth science remote sensing applications : instrument modifications and measurement procedures

    NARCIS (Netherlands)

    Hecker, C.; Hook, S.; Meijde, M. van der; Bakker, W.H.; Werff, H.M.A. van der; Wilbrink, H.J.; Ruitenbeek, F.J.A. van; Smeth, J.B. de; Meer, F.D. van der

    2011-01-01

    In this article we describe a new instrumental setup at the University of Twente Faculty ITC with an optimized processing chain to measure absolute directional-hemispherical reflectance values of typical earth science samples in the 2.5 to 16 μm range. A Bruker Vertex 70 FTIR spectrometer was chosen

  13. Calibration procedures for imaging spectrometers: improving data quality from satellite missions to UAV campaigns

    Science.gov (United States)

    Brachmann, Johannes F. S.; Baumgartner, Andreas; Lenhard, Karim

    2016-10-01

    The Calibration Home Base (CHB) at the Remote Sensing Technology Institute of the German Aerospace Center (DLR-IMF) is an optical laboratory designed for the calibration of imaging spectrometers for the VNIR/SWIR wavelength range. Radiometric, spectral and geometric characterization is realized in the CHB in a precise and highly automated fashion. This allows performing a wide range of time consuming measurements in an efficient way. The implementation of ISO 9001 standards ensures a traceable quality of results. DLR-IMF will support the calibration and characterization campaign of the future German spaceborne hyperspectral imager EnMAP. In the context of this activity, a procedure for the correction of imaging artifacts, such as due to stray light, is currently being developed by DLR-IMF. Goal is the correction of in-band stray light as well as ghost images down to a level of a few digital numbers in the whole wavelength range 420-2450 nm. DLR-IMF owns a Norsk Elektro Optikks HySpex airborne imaging spectrometer system that has been thoroughly characterized. This system will be used to test stray light calibration procedures for EnMAP. Hyperspectral snapshot sensors offer the possibility to simultaneously acquire hyperspectral data in two dimensions. Recently, these rather new spectrometers have arisen much interest in the remote sensing community. Different designs are currently used for local area observation such as by use of small unmanned aerial vehicles (sUAV). In this context the CHB's measurement capabilities are currently extended such that a standard measurement procedure for these new sensors will be implemented.

  14. Current Sounding Capability From Satellite Meteorological Observation With Ultraspectral Infrared Instruments

    Science.gov (United States)

    Zhou, Daniel K.; Liu, Xu; Larar, Allen M.

    2008-01-01

    Ultraspectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. The intent of the measurement of tropospheric thermodynamic state and trace abundances is the initialization of climate models and the monitoring of air quality. The NPOESS Airborne Sounder Testbed-Interferometer (NAST-I), designed to support the development of future satellite temperature and moisture sounders, aboard high altitude aircraft has been collecting data throughout many field campaigns. An advanced retrieval algorithm developed with NAST-I is now applied to satellite data collected with the Atmospheric InfraRed Sounder (AIRS) on the Aqua satellite launched on 4 May 2002 and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite launched on October 19, 2006. These instruments possess an ultra-spectral resolution, for example, both IASI and NAST-I have 0.25 cm-1 and a spectral coverage from 645 to 2760 cm-1. The retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. The physical inversion scheme has been developed, dealing with cloudy as well as cloud-free radiance observed with ultraspectral infrared sounders, to simultaneously retrieve surface, atmospheric thermodynamic, and cloud microphysical parameters. A fast radiative transfer model, which applies to the clouded atmosphere, is used for atmospheric profile and cloud parameter retrieval. A one-dimensional (1-d) variational multi-variable inversion solution is used to improve an iterative background state defined by an eigenvector-regression-retrieval. The solution is iterated in order to account for non-linearity in the 1-d variational solution. It is shown that relatively accurate temperature and moisture retrievals can be achieved below optically thin clouds. For optically thick clouds, accurate temperature and moisture profiles down to

  15. Satellite Map of Port-au-Prince, Haiti-2010-Infrared

    Science.gov (United States)

    Cole, Christopher J.; Sloan, Jeff

    2010-01-01

    The U.S. Geological Survey produced 1:24,000-scale post-earthquake image base maps incorporating high- and medium-resolution remotely sensed imagery following the 7.0 magnitude earthquake near the capital city of Port au Prince, Haiti, on January 12, 2010. Commercial 2.4-meter multispectral QuickBird imagery was acquired by DigitalGlobe on January 15, 2010, following the initial earthquake. Ten-meter multispectral ALOS AVNIR-2 imagery was collected by the Japanese Space Agency (JAXA) on January 12, 2010. These data were acquired under the Remote Sensing International Charter, a global team of space and satellite agencies that provide timely imagery in support of emergency response efforts worldwide. The images shown on this map were employed to support earthquake response efforts, specifically for use in determining ground deformation, damage assessment, and emergency management decisions. The raw, unprocessed imagery was geo-corrected, mosaicked, and reproduced onto a cartographic 1:24,000-scale base map. These maps are intended to provide a temporally current representation of post-earthquake ground conditions, which may be of use to decision makers and to the general public.

  16. High-pressure-low-temperature cryostat designed for use with fourier transform infrared spectrometers and time-resolved infrared spectroscopy.

    Science.gov (United States)

    Calladine, James A; Love, Ashley; Fields, Peter A; Wilson, Richard G M; George, Michael W

    2014-01-01

    The design for a new high-pressure-low-temperature infrared (IR) cell for performing experiments using conventional Fourier transform infrared or fast laser-based time-resolved infrared spectroscopy, in a range of solvents, is described. The design builds upon a commercially available compressor and cold end (Polycold PCC(®) and CryoTiger(®)), which enables almost vibration-free operation, ideal for use with sensitive instrumentation. The design of our cell and cryostat allows for the study of systems at temperatures from 77 to 310 K and at pressures up to 250 bar. The CaF2 windows pass light from the mid-IR to the ultraviolet (UV), enabling a number of experiments to be performed, such as Raman, UV-visible absorption spectroscopy, and time-resolved techniques where sample excitation/probing using continuous wave or pulsed lasers is required. We demonstrate the capabilities of this cell by detailing two different applications: (i) the reactivity of a range of Group V-VII organometallic alkane complexes using time-resolved spectroscopy on the millisecond timescale and (ii) the gas-to-liquid phase transition of CO2 at low temperature, which is applicable to measurements associated with transportation issues related to carbon capture and storage.

  17. Freeform lens collimating spectrum-folded Hadamard transform near-infrared spectrometer

    Science.gov (United States)

    Wang, Xiaoduo; Liu, Hua; Juschkin, Larissa; Li, Yunpeng; Xu, Jialin; Quan, Xiangqian; Lu, Zhenwu

    2016-12-01

    A novel Hadamard transform spectrometer collimated by a freeform lens has been designed, which doubles the working spectral range while the spectral resolution is maintained. The freeform lens is designed to redistribute the broadband spectra of the source from 800 nm to 2400 nm into two collimated beams with different wavelengths and different tilting angles, to achieve the folding of spectra on the digital micro-mirror devices (DMD). It is constructed by solving two partial differential equations. The grating diffraction efficiency of the two split beams are more uniform and higher compared with the traditional method. The simulation results show that the bandwidth of the spectrometer is doubled and the spectral resolution is better than 10 nm. The optical system becomes more compact, and the energy efficiency is improved by 11.98% by folding the spectra with one freeform lens and one grating.

  18. Miniature, Low-Power, Waveguide Based Infrared Fourier Transform Spectrometer for Spacecraft Remote Sensing

    Science.gov (United States)

    Hewagama, TIlak; Aslam, Shahid; Talabac, Stephen; Allen, John E., Jr.; Annen, John N.; Jennings, Donald E.

    2011-01-01

    Fourier transform spectrometers have a venerable heritage as flight instruments. However, obtaining an accurate spectrum exacts a penalty in instrument mass and power requirements. Recent advances in a broad class of non-scanning Fourier transform spectrometer (FTS) devices, generally called spatial heterodyne spectrometers, offer distinct advantages as flight optimized systems. We are developing a miniaturized system that employs photonics lightwave circuit principles and functions as an FTS operating in the 7-14 micrometer spectral region. The inteferogram is constructed from an ensemble of Mach-Zehnder interferometers with path length differences calibrated to mimic scan mirror sample positions of a classic Michelson type FTS. One potential long-term application of this technology in low cost planetary missions is the concept of a self-contained sensor system. We are developing a systems architecture concept for wide area in situ and remote monitoring of characteristic properties that are of scientific interest. The system will be based on wavelength- and resolution-independent spectroscopic sensors for studying atmospheric and surface chemistry, physics, and mineralogy. The self-contained sensor network is based on our concept of an Addressable Photonics Cube (APC) which has real-time flexibility and broad science applications. It is envisaged that a spatially distributed autonomous sensor web concept that integrates multiple APCs will be reactive and dynamically driven. The network is designed to respond in an event- or model-driven manner or reconfigured as needed.

  19. Step-scan Fourier transform infrared (FTIR) spectrometer for investigating chemical reactions of energy-related materials. Final report, April 1, 1995--March 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Eyring, E.M.

    1997-11-04

    Two step-scan Fourier transform infrared (FTIR) spectrometers were purchased with URI-DOE funds by the University of Utah. These infrared spectrometers have been used to carry out the following investigations: the determination of strength of adsorption of organic molecules at the liquid-solid interface of coated attenuated total reflectance (ATR) elements, the kinetic study of the photoinitiated polymerization of a dental resin, the exploration of the kinetics of photochemical reactions of organic molecules in solution, and the development of a stopped-flow FTIR interface for measuring rates and mechanisms of reactions in solution that are not photoinitiated and do not have convenient ultraviolet-visible spectral features.

  20. Particle contamination from Martin Optical Black. [in design of barrel baffle of Infrared Astronomical Satellite

    Science.gov (United States)

    Young, P. J.; Noll, R.; Andreozzi, L.; Hope, J.

    1981-01-01

    The design of the barrel baffle of the Infrared Astronomical Satellite (IRAS) Optical Subsystem to minimize production of particulate contamination is described. The configuration of the 50-inch long, 28.5-inch diameter baffle required pop-rivet assembly after coating with Martin Optical Black for stray light suppression. An experiment to determine the contamination produced at assembly led to the modification of the baffle construction to preclude such damage to the coated surfaces.

  1. Greenhouse Observations of the Stratosphere and Troposphere (GHOST): a novel shortwave infrared spectrometer developed for the Global Hawk unmanned aerial vehicle

    Science.gov (United States)

    Humpage, Neil; Boesch, Hartmut; Palmer, Paul; Parr-Burman, Phil; Vick, Andy; Bezawada, Naidu; Black, Martin; Born, Andy; Pearson, David; Strachan, Jonathan; Wells, Martyn

    2014-05-01

    The tropospheric distribution of greenhouse gases (GHGs) is dependent on surface flux variations, atmospheric chemistry and transport processes over a wide range of spatial and temporal scales. Errors in assumed atmospheric transport can adversely affect surface flux estimates inferred from surface, aircraft or satellite observations of greenhouse gas concentrations using inverse models. We present a novel, compact shortwave infrared spectrometer (GHOST) for installation on the NASA Global Hawk unmanned aerial vehicle to provide tropospheric column observations of CO2, CO, CH4, H2O and HDO over the ocean to address the need for large-scale, simultaneous, finely resolved measurements of key GHGs. These species cover a range of lifetimes and source processes, and measurements of their tropospheric columns will reflect the vertically integrated signal of their vertical and horizontal transport within the troposphere. The primary science objectives of GHOST are to: 1) provide observations which can be used to test atmospheric transport models; 2) validate satellite observations of GHG column observations over oceans, thus filling a critical gap in current validation capabilities; and 3) complement in-situ tropopause transition layer tracer observations from other instrumentation on board the Global Hawk to provide a link between upper and lower troposphere concentration measurements. The GHOST spectrometer system comprises a target acquisition module (TAM), a fibre slicer and feed system, and a multiple order spectrograph. The TAM design utilises a gimbal behind an optical dome, which is programmed to direct solar radiation reflected by the ocean surface into a fibre optic bundle. The fibre slicer and feed system then splits the light into the four spectral bands using order sorting filters. The fibres corresponding to each band are arranged with a small sideways offset to correctly centre each spectrum on the detector array. The spectrograph design is unique in that a

  2. Cloud mask via cumulative discriminant analysis applied to satellite infrared observations: scientific basis and initial evaluation

    Directory of Open Access Journals (Sweden)

    U. Amato

    2014-06-01

    Full Text Available We introduce a classification method (Cumulative Discriminant Analysis of the Discriminant Analysis type to discriminate between cloudy and clear sky satellite observations in the thermal infrared. The tool is intended for the high spectral resolution infrared sounder (IRS planned for the geostationary METEOSAT (Meteorological Satellite Third Generation platform and uses IASI (Infrared Atmospheric Sounding Interferometer data as a proxy. The Cumulative Discriminant Analysis does not introduce biases intrinsic with the approximation of the probability density functions and is flexible enough to adapt to different strategies to optimize the cloud mask. The methodology is based on nine statistics computed from IASI spectral radiances, which exploit the high spectral resolution of the instrument and which effectively summarize information contained within the IASI spectrum. A Principal Component Analysis prior step is also introduced which makes the problem more consistent with the statistical assumptions of the methodology. An initial assessment of the scheme is performed based on global and regional IASI real data sets and cloud masks obtained from AVHRR (Advanced Very High Resolution Radiometer and SEVIRI (Spinning Enhanced Visible and Infrared Imager imagers. The agreement with these independent cloud masks is generally well above 80%, except at high latitudes in their winter seasons.

  3. Cloud mask via cumulative discriminant analysis applied to satellite infrared observations: scientific basis and initial evaluation

    Science.gov (United States)

    Amato, U.; Lavanant, L.; Liuzzi, G.; Masiello, G.; Serio, C.; Stuhlmann, R.; Tjemkes, S. A.

    2014-10-01

    We introduce a classification method (cumulative discriminant analysis) of the discriminant analysis type to discriminate between cloudy and clear-sky satellite observations in the thermal infrared. The tool is intended for the high-spectral-resolution infrared sounder (IRS) planned for the geostationary METEOSAT (Meteorological Satellite) Third Generation platform and uses IASI (Infrared Atmospheric Sounding Interferometer) data as a proxy. The cumulative discriminant analysis does not introduce biases intrinsic with the approximation of the probability density functions and is flexible enough to adapt to different strategies to optimize the cloud mask. The methodology is based on nine statistics computed from IASI spectral radiances, which exploit the high spectral resolution of the instrument and which effectively summarize information contained within the IASI spectrum. A principal component analysis prior step is also introduced, which makes the problem more consistent with the statistical assumptions of the methodology. An initial assessment of the scheme is performed based on global and regional IASI real data sets and cloud masks obtained from AVHRR (Advanced Very High Resolution Radiometer) and SEVIRI (Spinning Enhanced Visible and Infrared Imager) imagers. The agreement with these independent cloud masks is generally well above 80 %, except at high latitudes in the winter seasons.

  4. The mid-infrared instrument for the James Webb Space Telescope: performance and operation of the Low-Resolution Spectrometer

    Science.gov (United States)

    Kendrew, Sarah; Scheithauer, Silvia; Bouchet, Patrice; Amiaux, Jerome; Azzollini, Ruymán.; Bouwman, Jeroen; Chen, Christine; Dubreuil, Didier; Fischer, Sebastian; Fox, Ori D.; Glasse, Alistair; Gordon, Karl; Greene, Tom; Hines, Dean C.; Lagage, Pierre-Olivier; Lahuis, Fred; Ronayette, Samuel; Wright, David; Wright, Gillian S.

    2016-07-01

    We describe here the performance and operational concept for the Low Resolution Spectrometer (LRS) of the mid-infrared instrument (MIRI) for the James Webb Space Telescope. The LRS will provide R˜100 slit and slitless spectroscopy from 5 to 12 micron, and its design is optimised for observations of compact sources, such as exoplanet host stars. We provide here an overview of the design of the LRS, and its performance as measured during extensive test campaigns, examining in particular the delivered image quality, dispersion, and resolving power, as well as spectrophotometric performance. The instrument also includes a slitless spectroscopy mode, which is optimally suited for transit spectroscopy of exoplanet atmospheres. We provide an overview of the operational procedures and the differences ahead of the JWST launch in 2018.

  5. Micro-Spec: An Ultra-Compact, High-Sensitivity Spectrometer for Far-Infrared and Sub-Millimeter Astronomy

    Science.gov (United States)

    Cataldo, Giuseppe; Hsieh, Wen-Ting; Huang, Wei-Chung; Moseley, S. Harvey; Stevenson, Thomas R.; Wollack, Edward J.

    2013-01-01

    High-performance, integrated spectrometers operating in the far-infrared and sub-millimeter promise to be powerful tools for the exploration of the epochs of reionization and initial galaxy formation. These devices, using high-efficiency superconducting transmission lines, can achieve the performance of a meter-scale grating spectrometer in an instrument implemented on a four-inch silicon wafer. Such a device, when combined with a cryogenic telescope in space, provides an enabling capability for studies of the early universe. Here, the optical design process for Micro-Spec (mu-Spec) is presented, with particular attention given to its two-dimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the stigmatization and minimization of the light path function in this bounded region, which results in an optimized geometrical configuration. A point design with an efficiency of approx. 90% has been developed for initial demonstration, and can serve as the basis for future instruments. Design variations on this implementation are also discussed, which can lead to lower efficiencies due to diffractive losses in the multimode region.

  6. Satellite observations of peroxyacetyl nitrate from the Aura Tropospheric Emission Spectrometer

    Science.gov (United States)

    Payne, V. H.; Alvarado, M. J.; Cady-Pereira, K. E.; Worden, J. R.; Kulawik, S. S.; Fischer, E. V.

    2014-11-01

    We present a description of the algorithm used to retrieve peroxyacetyl nitrate (PAN) concentrations from the Aura Tropospheric Emission Spectrometer (TES). We describe the spectral microwindows, error analysis, and the utilization of a priori and initial guess information provided by the GEOS-Chem global chemical transport model. The TES PAN retrievals contain up to one degree of freedom for signal. In general, the retrievals are most sensitive to PAN in the mid-troposphere. Estimated single-measurement uncertainties are on the order of 30 to 50%. The detection limit for a single TES measurement is dependent on the atmospheric and surface conditions as well as on the instrument noise. For observations where the cloud optical depth is less than 0.5, we find that the TES detection limit for PAN is in the region of 200 to 300 pptv. We show that PAN retrievals capture plumes associated with boreal burning. Retrievals over the Northern Hemisphere Pacific in springtime show spatial features that are qualitatively consistent with the expected distribution of PAN in outflow of Asian pollution.

  7. Using a near-infrared spectrometer to estimate the age of Anopheles mosquitoes exposed to pyrethroids

    Science.gov (United States)

    We report on the accuracy of using near-infrared spectroscopy (NIRS) to predict the age of Anopheles mosquitoes reared from wild larvae and a mixed age-wild adult population collected from pit traps after exposure to pyrethroids. The mosquitoes reared from wild larvae were estimated as ,7 or $7 d ol...

  8. The SOFIA/SAFIRE Far-Infrared Spectrometer: Highlighting Submillimeter Astrophysics and Technology

    Science.gov (United States)

    Benford, Dominic J.

    2009-01-01

    The Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory is an imaging spectrometer for wavelengths between 28 microns and 440 microns. Our design is a dual-band long-slit grating spectrometer, which provides broadband (approx. 4000 km/s) observations in two lines simultaneously over a field of view roughly 10" wide by 320" long. The low backgrounds in spectroscopy require very sensitive detectors with noise equivalent powers of order 10(exp -18) W/square root of Hz. We are developing a kilopixel, filled detector array for SAFIRE in a 32 x 40 format. The detector consists of a transition edge sensor (TES) bolometer array, a per-pixel broadband absorbing backshort array, and a NIST SQUID multiplexer readout array. This general type of array has been used successfully in the GISMO instrument, so we extrapolate to the sensitivity needed for airborne spectroscopy. Much of the cryogenic, electronics, and software infrastructure for SAFIRE have been developed. I provide here an overview of the progress on SAFIRE.

  9. Wide-Field InfraRed Survey Telescope (WFIRST) slitless spectrometer: design, prototype, and results

    Science.gov (United States)

    Gong, Qian; Content, David A.; Dominguez, Margaret; Emmett, Thomas; Griesmann, Ulf; Hagopian, John; Kruk, Jeffrey; Marx, Catherine; Pasquale, Bert; Wallace, Thomas; Whipple, Arthur

    2016-07-01

    The slitless spectrometer plays an important role in the WFIRST mission for the survey of emission-line galaxies. This will be an unprecedented very wide field, HST quality 3D survey of emission line galaxies1. The concept of the compound grism as a slitless spectrometer has been presented previously. The presentation briefly discusses the challenges and solutions of the optical design, and recent specification updates, as well as a brief comparison between the prototype and the latest design. However, the emphasis of this paper is the progress of the grism prototype: the fabrication and test of the complicated diffractive optical elements and powered prism, as well as grism assembly alignment and testing. Especially how to use different tools and methods, such as IR phase shift and wavelength shift interferometry, to complete the element and assembly tests. The paper also presents very encouraging results from recent element tests to assembly tests. Finally we briefly touch the path forward plan to test the spectral characteristic, such as spectral resolution and response.

  10. The Mid-Infrared Instrument for the James Webb Space Telescope, VI: The Medium Resolution Spectrometer

    CERN Document Server

    Wells, Martyn; Glasse, Alistair; Wright, G S; Aitink-Kroes, Gabby; Azzollini, Ruyman; Beard, Steven; Brandl, B R; Gallie, Angus; Geers, V C; Glauser, A M; Hastings, Peter; Henning, Th; Jager, Rieks; Justtanont, K; Kruizinga, Bob; Lahuis, Fred; Lee, David; Martinez-Delgado, I; Martinez-Galarza, J R; Meijers, M; Morrison, Jane E; Mueller, Friedrich; Nakos, Thodori; O'Sullivan, Brian; Oudenhuysen, Ad; Parr-Burman, P; Pauwels, Evert; Rohloff, R -R; Schmalzl, Eva; Sykes, Jon; Thelen, M P; van Dishoeck, E F; Vandenbussche, Bart; Venema, Lars B; Visser, Huib; Waters, L B F M; Wright, David

    2015-01-01

    We describe the design and performance of the Medium Resolution Spectrometer (MRS) for the JWST-MIRI instrument. The MRS incorporates four coaxial spectral channels in a compact opto-mechanical layout that generates spectral images over fields of view up to 7.7 X 7.7 arcseconds in extent and at spectral resolving powers ranging from 1,300 to 3,700. Each channel includes an all-reflective integral field unit (IFU): an 'image slicer' that reformats the input field for presentation to a grating spectrometer. Two 1024 X 1024 focal plane arrays record the output spectral images with an instantaneous spectral coverage of approximately one third of the full wavelength range of each channel. The full 5 to 28.5 micron spectrum is then obtained by making three exposures using gratings and pass-band-determining filters that are selected using just two three-position mechanisms. The expected on-orbit optical performance is presented, based on testing of the MIRI Flight Model and including spectral and spatial coverage an...

  11. Mid-Infrared Spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 2. Determination of the Mean Composition of the Upper Troposphere and Stratosphere

    CERN Document Server

    Orton, Glenn S; Fletcher, Leigh N; Mainzer, Amy K; Hines, Dean; Hammel, Heidi B; Martin-Torres, Javier; Burgdorf, Martin; Merlet, Cecile; Line, Michael R

    2014-01-01

    Mid-infrared spectral observations Uranus acquired with the Infrared Spectrometer (IRS) on the Spitzer Space Telescope are used to determine the abundances of C2H2, C2H6, CH3C2H, C4H2, CO2, and tentatively CH3 on Uranus at the time of the 2007 equinox. For vertically uniform eddy diffusion coefficients in the range 2200-2600 cm2 s-1, photochemical models that reproduce the observed methane emission also predict C2H6 profiles that compare well with emission in the 11.6-12.5 micron wavelength region, where the nu9 band of C2H6 is prominent. Our nominal model with a uniform eddy diffusion coefficient Kzz = 2430 cm2 sec-1 and a CH4 tropopause mole fraction of 1.6x10-5 provides a good fit to other hydrocarbon emission features, such as those of C2H2 and C4H2, but the model profile for CH3C2H must be scaled by a factor of 0.43, suggesting that improvements are needed in the chemical reaction mechanism for C3Hx species. The nominal model is consistent with a CH3D/CH4 ratio of 3.0+-0.2x10-4. From the best-fit scaling...

  12. Dynamics and Evolution of SO2 Gas Condensation Around Prometheus-like Volcanic Plumes on Io as Seen by the Near Infrared Mapping Spectrometer

    Science.gov (United States)

    Doute, S.; Lopes-Gautier, R.; Smythe, W. D.; Kamp, L. W.; Carlson, R.

    2001-01-01

    Near Infrared Mapping Spectrometer data acquired during the I24, 25, and 27 Io's Fly-bys by Galileo are analyzed to map the SO2 frost abundance and granularity. This allows a better understanding of the dynamics and evolution of gas condensation around volcanic plumes. Additional information is contained in the original extended abstract.

  13. Non-collinear upconversion of incoherent light: designing infrared spectrometers and imaging systems

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Hu, Qi; Pedersen, Christian

    2014-01-01

    for each angle of propagation. Non-collinear phase matching has been an area of limited attention for many years due to inherent incompatibility with tightly focused laser beams typically used for most second order processes in order to achieve acceptable conversion efficiency. The development......Upconversion of incoherent mid-infrared radiation to near visible wavelengths, offers very attractive sensitivity compared to conventional means of infrared detection. Incoherent light, focused into a nonlinear crystal, results in noncollinear phase matching of a narrow range of wavelengths...... of periodically poled crystals have allowed for non-critical collinear phase matching of most wavelengths, virtually eliminating the need for non-collinear phase matching. When considering upconversion of thermal light, spectral radiance is limited due to the finite temperature of the Planck radiation source...

  14. [Rapid discriminating hogwash oil and edible vegetable oil using near infrared optical fiber spectrometer technique].

    Science.gov (United States)

    Zhang, Bing-Fang; Yuan, Li-Bo; Kong, Qing-Ming; Shen, Wei-Zheng; Zhang, Bing-Xiu; Liu, Cheng-Hai

    2014-10-01

    In the present study, a new method using near infrared spectroscopy combined with optical fiber sensing technology was applied to the analysis of hogwash oil in blended oil. The 50 samples were a blend of frying oil and "nine three" soybean oil according to a certain volume ratio. The near infrared transmission spectroscopies were collected and the quantitative analysis model of frying oil was established by partial least squares (PLS) and BP artificial neural network The coefficients of determina- tion of calibration sets were 0.908 and 0.934 respectively. The coefficients of determination of validation sets were 0.961 and 0.952, the root mean square error of calibrations (RMSEC) was 0.184 and 0.136, and the root mean square error of predictions (RMSEP) was all 0.111 6. They conform to the model application requirement. At the same time, frying oil and qualified edible oil were identified with the principal component analysis (PCA), and the accurate rate was 100%. The experiment proved that near infrared spectral technology not only can quickly and accurately identify hogwash oil, but also can quantitatively detect hog- wash oil. This method has a wide application prospect in the detection of oil.

  15. The Mid-Infrared Instrument for the James Webb Space Telescope: IV. The Low Resolution Spectrometer

    CERN Document Server

    Kendrew, S; Bouchet, P; Amiaux, J; Azzolini, R; Bouwman, J; Chen, C; Dubreuil, D; Fischer, S; Glasse, A; Greene, T; Lagage, P -O; Lahuis, F; Ronayette, S; Wright, D; Wright, G S

    2015-01-01

    The Low Resolution Spectrometer of the MIRI, which forms part of the imager module, will provide R~100 long-slit and slitless spectroscopy from 5 to 12 micron. The design is optimised for observations of compact sources, such as exoplanet host stars. We provide here an overview of the design of the LRS, and its performance as measured during extensive test campaigns, examining in particular the delivered image quality, dispersion, and resolving power, as well as spectrophotometric performance, flatfield accuracy and the effects of fringing. We describe the operational concept of the slitless mode, which is optimally suited to transit spectroscopy of exoplanet atmospheres. The LRS mode of the MIRI was found to perform consistently with its requirements and goals.

  16. Evaluation of a physically-based snow model with infrared and microwave satellite-derived estimates

    Science.gov (United States)

    Wang, L.

    2013-05-01

    Snow (with high albedo, as well as low roughness and thermal conductivity) has significant influence on the land-atmosphere interactions in the cold climate and regions of high elevation. The spatial and temporal variability of the snow distribution on a basin scale greatly determines the timing and magnitude of spring snowmelt runoff. For improved water resources management, a physically-based distributed snow model has been developed and applied to the upper Yellow River Basin to provide the outputs of snow variables as well as streamflows from 2001 to 2005. Remotely-sensed infrared information from MODIS satellites has been used to evaluate the model's outputs of spatially-distributed snow cover extent (SCE) and land surface temperature (LST); while the simulated snow depth (SD) and snow water equivalent (SWE) have been compared with the microwave information from SSM/I and AMSR-E satellites. In general, the simulated streamflows (including spring snowmelt) agree fairly well with the gauge-based observations; while the modeled snow variables show acceptable accuracies through comparing to various satellite-derived estimates from infrared or microwave information.;

  17. Search for astronomical sites suitable for infrared observations using GOES satellite images

    Science.gov (United States)

    Ducati, Jorge R.; Feijo, Eleandro S.

    2003-04-01

    Images from GOES satellite were used to develop a method to search for sites suitable to astronomical observations in the infrared. An area of study located in the Peruvian Andes was chosen, with altitudes above 2500 m. Forty-three images from the GOES meteorological satellite in channels 3, 4 and 5 were used. The GOES images, spanning an 11-day period, in each channel, were combined to produced images expressing the surface visibility in each channel. Atmospheric turbulence could be estimated from the variation of visibility over six-hour periods, with one image per hour. As criteria to classify sites on the Andes, we combined information on altitude, visibility of the surface in the infrared, the amount of water vapor in the atmosphere, and atmospheric turbulence. Results of this new method showed that the region of Moquegua, in South Peru, is to be preferred in surveys for astronomical sites. Comparisons with results from other investigators, which used other approaches, indicated that this methodology can produce valid results and can be applied to studies covering larger periods. The general results of this study indicate that the method is valid and can effectively be used as an important resource in surveys for infrared astronomical sites.

  18. Search for astronomical sites suitable for infrared observations using goes satellite images release

    Science.gov (United States)

    Ducati, J. R.; Feijó, E.

    2003-08-01

    Astronomical sites are traditionally found after studies performed over many years, including preliminary selection of places based in general information on climate, clear skies and logistical adequacy. It follows extensive "in situ" monitoring of seeing and cloudiness. Theses procedures are long and expensive, and alternatives can be looked for. In this study, images from GOES meteorological satellite were used to develop a method to search for sites suitable to astronomical observations in the infrared. An area of study located in the Peruvian Andes was chosen, with altitudes above 2500 m. 43 images from the GOES meteorological satellite in chanels 3, 4 and 5 were used. The GOES images, spanning a 11-day period, in each channel, were combined to produced images expressing the surface visibility in each channel. Atmospheric turbulence could be estimated from the variation of visibility over six-hour periods, with one image per hour. As criteria to classify sites on the Andes, we combined information on altitude, visibility of the surface in the infrared, the amount of water vapor in the atmosphere, and atmospheric turbulence. Results of this new method showed that the region of Moquegua, in South Peru, is to be preferred in surveys for astronomical sites. Comparisons with results from other investigators, which used other approaches, indicated that this methodology produces valid results and can be used to studies spanning larger periods. The general results of this study indicate that the method can efectively be used as an important resource in surveys for infrared astronomical sites

  19. Non-Contact Measurement of the Spectral Emissivity through Active/Passive Synergy of CO₂ Laser at 10.6 µm and 102F FTIR (Fourier Transform Infrared) Spectrometer.

    Science.gov (United States)

    Zhang, Ren-Hua; Su, Hong-Bo; Tian, Jing; Mi, Su-Juan; Li, Zhao-Liang

    2016-06-24

    In the inversion of land surface temperature (LST) from satellite data, obtaining the information on land surface emissivity is most challenging. How to solve both the emissivity and the LST from the underdetermined equations for thermal infrared radiation is a hot research topic related to quantitative thermal infrared remote sensing. The academic research and practical applications based on the temperature-emissivity retrieval algorithms show that directly measuring the emissivity of objects at a fixed thermal infrared waveband is an important way to close the underdetermined equations for thermal infrared radiation. Based on the prior research results of both the authors and others, this paper proposes a new approach of obtaining the spectral emissivity of the object at 8-14 µm with a single-band CO₂ laser at 10.6 µm and a 102F FTIR spectrometer. Through experiments, the spectral emissivity of several key samples, including aluminum plate, iron plate, copper plate, marble plate, rubber sheet, and paper board, at 8-14 µm is obtained, and the measured data are basically consistent with the hemispherical emissivity measurement by a Nicolet iS10 FTIR spectrometer for the same objects. For the rough surface of materials, such as marble and rusty iron, the RMSE of emissivity is below 0.05. The differences in the field of view angle and in the measuring direction between the Nicolet FTIR method and the method proposed in the paper, and the heterogeneity in the degree of oxidation, polishing and composition of the samples, are the main reasons for the differences of the emissivities between the two methods.

  20. Non-Contact Measurement of the Spectral Emissivity through Active/Passive Synergy of CO2 Laser at 10.6 µm and 102F FTIR (Fourier Transform Infrared) Spectrometer

    Science.gov (United States)

    Zhang, Ren-Hua; Su, Hong-Bo; Tian, Jing; Mi, Su-Juan; Li, Zhao-Liang

    2016-01-01

    In the inversion of land surface temperature (LST) from satellite data, obtaining the information on land surface emissivity is most challenging. How to solve both the emissivity and the LST from the underdetermined equations for thermal infrared radiation is a hot research topic related to quantitative thermal infrared remote sensing. The academic research and practical applications based on the temperature-emissivity retrieval algorithms show that directly measuring the emissivity of objects at a fixed thermal infrared waveband is an important way to close the underdetermined equations for thermal infrared radiation. Based on the prior research results of both the authors and others, this paper proposes a new approach of obtaining the spectral emissivity of the object at 8–14 µm with a single-band CO2 laser at 10.6 µm and a 102F FTIR spectrometer. Through experiments, the spectral emissivity of several key samples, including aluminum plate, iron plate, copper plate, marble plate, rubber sheet, and paper board, at 8–14 µm is obtained, and the measured data are basically consistent with the hemispherical emissivity measurement by a Nicolet iS10 FTIR spectrometer for the same objects. For the rough surface of materials, such as marble and rusty iron, the RMSE of emissivity is below 0.05. The differences in the field of view angle and in the measuring direction between the Nicolet FTIR method and the method proposed in the paper, and the heterogeneity in the degree of oxidation, polishing and composition of the samples, are the main reasons for the differences of the emissivities between the two methods. PMID:27347964

  1. Using a near-infrared spectrometer to estimate the age of anopheles mosquitoes exposed to pyrethroids.

    Science.gov (United States)

    Sikulu, Maggy T; Majambere, Silas; Khatib, Bakar O; Ali, Abdullah S; Hugo, Leon E; Dowell, Floyd E

    2014-01-01

    We report on the accuracy of using near-infrared spectroscopy (NIRS) to predict the age of Anopheles mosquitoes reared from wild larvae and a mixed age-wild adult population collected from pit traps after exposure to pyrethroids. The mosquitoes reared from wild larvae were estimated as 8 d for both susceptible and resistant groups. The age structure of wild-collected mosquitoes was not significantly different for the pyrethroid-susceptible and pyrethroid-resistant mosquitoes (P = 0.210). Based on these findings, NIRS chronological age estimation technique for Anopheles mosquitoes may be independent of insecticide exposure and the environmental conditions to which the mosquitoes are exposed.

  2. Miniaturized infrared-spectrometers for monitoring oil condition in offshore wind turbines; Miniaturisierte Infrarot-Spektrometer zur Oelzustandsueberwachung in Offshore-Windkraftgetriebe

    Energy Technology Data Exchange (ETDEWEB)

    Wiesent, Benjamin R.; Dorigo, Daniel G.; Simsek, Oezlem; Koch, Alexander W. [Technische Univ. Muenchen (Germany). Lehrstuhl fuer Messsystem- und Sensortechnik

    2012-07-01

    Infrared-based oil condition sensors provide valuable information about the condition of gears and thus permit long-term planning of maintenance work. Currently available systems are mainly based on non-dispersive methods providing information about one single oil condition parameter only. In many cases they are even adapted to only one type of oil. Miniaturized infrared spectrometers offer the possibility to simultaneously acquire a wealth of relevant oil condition parameters and are also applicable to a broad range of oil types. In this paper we present a method for selecting an appropriate spectral apparatus based on a multivariate calibration. We also show and discuss limitations of the respective spectral apparatus in terms of spectral bandwidth, resolution, and SNR on the quality of spectral data analysis. In addition, the realization and measurement results of a miniaturized infrared spectrometer are shown based on a linear variable filter (LVF) for gear oil monitoring of offshore wind turbine gearboxes.

  3. Novel Fourier transform infrared spectrometer architecture based on cascaded Fabry-Perot interferometers

    Science.gov (United States)

    Eltagoury, Yomna M.; Sabry, Yasser M.; Khalil, Diaa A.

    2016-03-01

    In this work, we present a novel architecture for Fourier transform spectrometers based on cascaded low-finesse FP interferometers. One of the interferometers has fixed path length while the second is a scanning one using a relatively large stroke electrostatic comb-drive actuator. The fixed interferometer results in a spectrum modulation and, hence, a shifted version of the interferogram away from the point of the zero spacing between the two mirrors. The shifted interferogram can then be used with the Fourier transform algorithm to obtain the spectrum of the measured light. This cascaded FP configuration results in a simple arrangement of mirrors on a line, which makes it much tolerant to misalignment errors. The proposed configuration is implemented using the MEMS DRIE technology on an SOI wafer with a simple MEMS process flow without metallization or dielectric coating of the vertical optical surface. The fabricated compact structure is measured with both a laser source with narrow spectrum at 1550 nm and a wide spectrum source composed of an SLED and the ASE of a semiconductor optical amplifier source. The obtained results validate the concept of the new configuration.

  4. A method to correct sampling ghosts in historic near-infrared Fourier Transform Spectrometer (FTS measurements

    Directory of Open Access Journals (Sweden)

    S. Dohe

    2013-04-01

    Full Text Available The Total Carbon Column Observing Network (TCCON has been established to provide ground-based remote sensing measurements of the column-average dry air mole fractions of key greenhouse gases. To ensure the network wide consistency, biases between Fourier Transform spectrometers at different sites have to be well controlled. In this study we investigate a fundamental correction scheme for errors in the sampling of the interferogram. This is a two-step procedure in which the laser sampling error (LSE is quantified using a subset of suitable interferograms and then used to resample all the interferograms in the timeseries. Timeseries of measurements acquired at the TCCON sites Izaña and Lauder are used to demonstrate the method. At both sites the sampling error histories show changes in LSE due to instrument interventions. Estimated LSE are in good agreement with sampling errors inferred from lamp measurements of the ghost to parent ratio (Lauder. The LSE introduce retrieval biases which are minimised when the interferograms are resampled. The original timeseries of Xair and XCO2 at both sites show discrepancies of 0.2–0.5% due to changes in the LSE associated with instrument interventions or changes in the measurement sample rate. After resampling discrepancies are reduced to 0.1% at Lauder and 0.2% at Izaña. In the latter case, coincident changes in interferometer alignment may also contribute to the residual difference.

  5. Astrometry and Near-Infrared Photometry of Neptune's Inner Satellites and Ring Arcs

    Science.gov (United States)

    Dumas, Christophe; Terrile, Richard J.; Smith, Bradford A.; Schneider, Glenn

    2002-03-01

    We report 1.87 μm photometry and astrometry of the inner satellites (Proteus, Larissa, Galatea, and Despina) and ring arcs of Neptune, obtained with the Hubble Space Telescope and its near-infrared camera NICMOS. From comparison with the Voyager data obtained at visible wavelengths, the small bodies orbiting within the ring region of Neptune have a near-infrared albedo consistently low, but higher than at visible wavelengths for most of the satellites, ranging from p1.87μm=0.058 (Despina) to p1.87μm=0.094 (Proteus). The ring arcs display a reddish spectral response similar to the satellites' in the 0.5-1.9 μm wavelength range. If we consider an earlier photometric measurement of Proteus obtained at K band, the satellite's albedo shows a depression at 2.2 μm that could be the first spectral evidence for the presence of CH or CN bearing material on its surface. Although astrometry of the inner moons of Neptune yields positions consistent with the predictions derived from Voyager images, the long time base between the Voyager and NICMOS observations allows us to refine our knowledge of their mean motions and semimajor axes, and to decrease the errors associated with these measurements. In addition, we confirm a mismatch between the mean semimajor axis of the ring arcs and the location of the 42:43 corotation inclined resonance due to Galatea. This result calls into question the ability of this resonance to confine the arcs azimuthally.

  6. Digital Meteorological Radar Data Compared with Digital Infrared Data from a Geostationary Meteorological Satellite.

    Science.gov (United States)

    1979-05-01

    datai uwere tab~ulaited for compariso;cn with the infrared satellite data) j 20 CIIA1iLTR Ml GEOSTAT] ONAPY ME LW)L- C , TIL LF K Meteorolccj isa I sate...8217):U S f 3 ’ 1 t ’ Iv . e , :]~L ’ bI 1 T-4 THY:-, L,’AClvT!P 3 AND IMVIC]l C t101 KRV~;It Tb 3 ( ji~u>:2;cat L ii 2 ’GD ~Of the L~r [2 u : ~~ I~ rtu ~j

  7. Identifying clouds over the Pierre Auger Observatory using infrared satellite data

    Science.gov (United States)

    Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Baughman, B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; De La Vega, G.; de Mello, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fliescher, S.; Fox, B. D.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glaser, C.; Glass, H.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Mariş, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Niggemann, T.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Peķala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Pfendner, C.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Ponce, V. H.; Pontz, M.; Porcelli, A.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schröder, F. G.; Schulz, J.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Straub, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Taşcău, O.; Tcaciuc, R.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Tridapalli, D. B.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano Garcia, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.

    2013-12-01

    We describe a new method of identifying night-time clouds over the Pierre Auger Observatory using infrared data from the Imager instruments on the GOES-12 and GOES-13 satellites. We compare cloud identifications resulting from our method to those obtained by the Central Laser Facility of the Auger Observatory. Using our new method we can now develop cloud probability maps for the 3000 km2 of the Pierre Auger Observatory twice per hour with a spatial resolution of ˜2.4 km by ˜5.5 km. Our method could also be applied to monitor cloud cover for other ground-based observatories and for space-based observatories.

  8. Identifying clouds over the Pierre Auger Observatory using infrared satellite data

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Pedro; et al.,

    2013-12-01

    We describe a new method of identifying night-time clouds over the Pierre Auger Observatory using infrared data from the Imager instruments on the GOES-12 and GOES-13 satellites. We compare cloud identifications resulting from our method to those obtained by the Central Laser Facility of the Auger Observatory. Using our new method we can now develop cloud probability maps for the 3000 km^2 of the Pierre Auger Observatory twice per hour with a spatial resolution of ~2.4 km by ~5.5 km. Our method could also be applied to monitor cloud cover for other ground-based observatories and for space-based observatories.

  9. A Widely Tunable Infrared Laser Spectrometer for Measurements of Isotopic Ratios of Carbon Cycle Gases

    Energy Technology Data Exchange (ETDEWEB)

    Joanne H. Shorter; J. Barry McManus; David D. Nelson; Charles E. Kolb; Mark S. Zahniser; Ray Bambha; Uwe Lehmann; Tomas Kulp; Stanley C. Tyler

    2005-01-31

    The atmospheric abundances of carbon dioxide and methane have increased dramatically during the industrial era. Measurements of the isotopic composition of these gases can provide a powerful tool for quantifying their sources and sinks. This report describes the development of a portable instrument for isotopic analysis CO{sub 2} and CH{sub 4} using tunable infrared laser absorption spectroscopy. This instrument combines novel optical design and signal processing methods with a widely tunable mid-infrared laser source based on difference frequency generation (DFG) which will can access spectral regions for all the isotopes of CO{sub 2} and CH{sub 4} with a single instrument. The instrument design compensates for the large difference in concentration between major and minor isotopes by measuring them with path lengths which differ by a factor of 100 within the same multipass cell. During Phase I we demonstrated the basic optical design and signal processing by determining {sup 13}CO{sub 2} isotopic ratios with precisions as small as 0.2{per_thousand} using a conventional lead salt diode laser. During Phase II, the DFG laser source was coupled with the optical instrument and was demonstrated to detect {sup 13}CH{sub 4}/{sup 12}CH{sub 4} ratios with a precision of 0.5{per_thousand} and an averaging time of 20 s using concentrated methane in air with a mixing ratio of 2700 ppm. Methods for concentrating ambient air for isotopic analysis using this technique have been evaluated. Extensions of this instrument to other species such as {sup 13}CO{sub 2}, C{sup 18}OO, and CH{sub 3}D are possible by substituting lasers at other wavelengths in the DFG source module. The immediate commercial application of this instrument will be to compete with existing mass spectrometric isotope instruments which are expensive, large and relatively slow. The novel infrared source developed in this project can be applied to the measurement of many other gas species and will have wide

  10. A method to correct sampling ghosts in historic near-infrared Fourier transform spectrometer (FTS measurements

    Directory of Open Access Journals (Sweden)

    S. Dohe

    2013-08-01

    Full Text Available The Total Carbon Column Observing Network (TCCON has been established to provide ground-based remote sensing measurements of the column-averaged dry air mole fractions (DMF of key greenhouse gases. To ensure network-wide consistency, biases between Fourier transform spectrometers at different sites have to be well controlled. Errors in interferogram sampling can introduce significant biases in retrievals. In this study we investigate a two-step scheme to correct these errors. In the first step the laser sampling error (LSE is estimated by determining the sampling shift which minimises the magnitude of the signal intensity in selected, fully absorbed regions of the solar spectrum. The LSE is estimated for every day with measurements which meet certain selection criteria to derive the site-specific time series of the LSEs. In the second step, this sequence of LSEs is used to resample all the interferograms acquired at the site, and hence correct the sampling errors. Measurements acquired at the Izaña and Lauder TCCON sites are used to demonstrate the method. At both sites the sampling error histories show changes in LSE due to instrument interventions (e.g. realignment. Estimated LSEs are in good agreement with sampling errors inferred from the ratio of primary and ghost spectral signatures in optically bandpass-limited tungsten lamp spectra acquired at Lauder. The original time series of Xair and XCO2 (XY: column-averaged DMF of the target gas Y at both sites show discrepancies of 0.2–0.5% due to changes in the LSE associated with instrument interventions or changes in the measurement sample rate. After resampling, discrepancies are reduced to 0.1% or less at Lauder and 0.2% at Izaña. In the latter case, coincident changes in interferometer alignment may also have contributed to the residual difference. In the future the proposed method will be used to correct historical spectra at all TCCON sites.

  11. A method to correct sampling ghosts in historic near-infrared Fourier transform spectrometer (FTS) measurements

    Science.gov (United States)

    Dohe, S.; Sherlock, V.; Hase, F.; Gisi, M.; Robinson, J.; Sepúlveda, E.; Schneider, M.; Blumenstock, T.

    2013-08-01

    The Total Carbon Column Observing Network (TCCON) has been established to provide ground-based remote sensing measurements of the column-averaged dry air mole fractions (DMF) of key greenhouse gases. To ensure network-wide consistency, biases between Fourier transform spectrometers at different sites have to be well controlled. Errors in interferogram sampling can introduce significant biases in retrievals. In this study we investigate a two-step scheme to correct these errors. In the first step the laser sampling error (LSE) is estimated by determining the sampling shift which minimises the magnitude of the signal intensity in selected, fully absorbed regions of the solar spectrum. The LSE is estimated for every day with measurements which meet certain selection criteria to derive the site-specific time series of the LSEs. In the second step, this sequence of LSEs is used to resample all the interferograms acquired at the site, and hence correct the sampling errors. Measurements acquired at the Izaña and Lauder TCCON sites are used to demonstrate the method. At both sites the sampling error histories show changes in LSE due to instrument interventions (e.g. realignment). Estimated LSEs are in good agreement with sampling errors inferred from the ratio of primary and ghost spectral signatures in optically bandpass-limited tungsten lamp spectra acquired at Lauder. The original time series of Xair and XCO2 (XY: column-averaged DMF of the target gas Y) at both sites show discrepancies of 0.2-0.5% due to changes in the LSE associated with instrument interventions or changes in the measurement sample rate. After resampling, discrepancies are reduced to 0.1% or less at Lauder and 0.2% at Izaña. In the latter case, coincident changes in interferometer alignment may also have contributed to the residual difference. In the future the proposed method will be used to correct historical spectra at all TCCON sites.

  12. Characterizing a Quantum Cascade Tunable Infrared Laser Differential Absorption Spectrometer (QC-TILDAS for measurements of atmospheric ammonia

    Directory of Open Access Journals (Sweden)

    R. A. Ellis

    2009-12-01

    Full Text Available A compact, fast-response Quantum Cascade Tunable Infrared Laser Differential Absorption Spectrometer (QC-TILDAS for measurements of ammonia has been evaluated under both laboratory and field conditions. Absorption of radiation from a pulsed, thermoelectrically cooled QC laser occurs at reduced pressure in a 0.5 L multiple pass absorption cell with an effective path length of 76 m. Detection is achieved using a thermoelectrically cooled Mercury Cadmium Telluride (HgCdTe infrared detector. A novel sampling inlet was used, consisting of a short, heated, quartz tube with a hydrophobic coating to minimize the adsorption of ammonia to surfaces. The inlet contains a critical orifice that reduces the pressure, a virtual impactor for separation of particles, and additional ports for delivering ammonia-free background air and calibration gas standards. This instrument has been found to have a detection limit of 0.23 ppb at 1 Hz. The sampling technique has been compared to the results of a conventional lead salt Tunable Diode Laser Absorption Spectrometer (TDLAS during a laboratory intercomparison. The effect of humidity and heat on the surface interaction of ammonia with sample tubing was investigated at mixing ratios ranging from 30–1000 ppb. Humidity was seen to worsen the ammonia time response and considerable improvement was observed when using a heated sampling line. A field intercomparison of the QC-TILDAS with a modified Thermo 42CTL chemiluminescence based analyzer was also performed at Environment Canada's Centre for Atmospheric Research Experiments (CARE in the rural town of Egbert, ON between May–July 2008. Background tests and calibrations using two different permeation tube sources and an ammonia gas cylinder were regularly carried out throughout the study. Results indicate a very good correlation with 1 min time resolution (R2=0.93 between the two instruments at the beginning of the study, when regular background

  13. Characterizing a Quantum Cascade Tunable Infrared Laser Differential Absorption Spectrometer (QC-TILDAS for measurements of atmospheric ammonia

    Directory of Open Access Journals (Sweden)

    R. A. Ellis

    2010-03-01

    Full Text Available A compact, fast-response Quantum Cascade Tunable Infrared Laser Differential Absorption Spectrometer (QC-TILDAS for measurements of ammonia (NH3 has been evaluated under both laboratory and field conditions. Absorption of radiation from a pulsed, thermoelectrically cooled QC laser occurs at reduced pressure in a 0.5 L multiple pass absorption cell with an effective path length of 76 m. Detection is achieved using a thermoelectrically-cooled Mercury Cadmium Telluride (HgCdTe infrared detector. A novel sampling inlet was used, consisting of a short, heated, quartz tube with a hydrophobic coating to minimize the adsorption of NH3 to surfaces. The inlet contains a critical orifice that reduces the pressure, a virtual impactor for separation of particles, and additional ports for delivering NH3-free background air and calibration gas standards. The level of noise in this instrument has been found to be 0.23 ppb at 1 Hz. The sampling technique has been compared to the results of a conventional lead salt Tunable Diode Laser Absorption Spectrometer (TDLAS during a laboratory intercomparison. The effect of humidity and heat on the surface interaction of NH3 with sample tubing was investigated at mixing ratios ranging from 30–1000 ppb. Humidity was seen to worsen the NH3 time response and considerable improvement was observed when using a heated sampling line. A field intercomparison of the QC-TILDAS with a modified Thermo 42CTL chemiluminescence-based analyzer was also performed at Environment Canada's Centre for Atmospheric Research Experiments (CARE in the rural town of Egbert, ON between May–July 2008. Background tests and calibrations using two different permeation tube sources and an NH3 gas cylinder were regularly carried out throughout the study. Results indicate a very good correlation at 1 min time resolution (R2 = 0.93 between the two instruments at the

  14. Using Isotope Ratio Infrared Spectrometer to determine δ13C and δ18O of carbonate samples

    Science.gov (United States)

    Smajgl, Danijela; Stöbener, Nils; Mandic, Magda

    2017-04-01

    The isotopic composition of calcifying organisms is a key tool for reconstruction past seawater temperature and water chemistry. Therefore stable carbon and oxygen isotopes (δ13C and δ18O) in carbonates have been widely used for reconstruction of paleoenvironments. Precise and accurate determination of isotopic composition of carbon (13C) and oxygen (18O) from carbonate sample with proper referencing and data evaluation algorithm presents a challenge for scientists. Mass spectrometry was the only widely used technique for this kind of analysis, but recent advances make laser based spectroscopy a viable alternative. The Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer (IRIS) analyzer with the Universal Reference Interface (URI) Connect is one of those alternatives and with TELEDYNE Cetac ASX-7100 autosampler extends the traditional offerings with a system of high precision and throughput of samples. To establish precision and accuracy of measurements and also to develop optimal sample preparation method for measurements with Delta Ray IRIS and URI Connect, IAEA reference materials were used. Preparation is similar to a Gas Bench II method. Carbonate material is added into the vials, flushed with CO2 free synthetic air and acidified with few droplets of 104% H3PO4. Sample amount used for analysis can be as low as 200 μg. Samples are measured after acidification and equilibration time of one hour at 70°C. The CO2 gas generated by reaction is flushed into the variable volume inside the URI Connect through the Nafion based built-in water trap. For this step, carrier gas (CO2 free air) is used to flush the gas from the vial into the variable volume with a maximum volume of 100 ml. A small amount of the sample is then used for automatic concentration determination present in the variable volume. The Thermo Scientific Qtegra Software automatically adjusts any additional dilution of the sample to achieve the desired concentration (usually 400 ppm) in the

  15. NOAA Climate Data Record (CDR) of Gridded Satellite Data from ISCCP B1 (GridSat-B1) Infrared Channel Brightness Temperature, Version 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Gridded Satellite (GridSat-B1) data provides a uniform set of quality controlled geostationary satellite observations for the visible, infrared window and...

  16. Tropospheric Emission Spectrometer (TES) satellite observations of ammonia, methanol, formic acid, and carbon monoxide over the Canadian oil sands: validation and model evaluation

    Science.gov (United States)

    The wealth of air quality information provided by satellite infrared observations of ammonia (NH3), carbon monoxide (CO), formic acid (HCOOH), and methanol (CH3OH) is currently being explored and used for a number of applications, especially at regional or global scales. These ap...

  17. Using a near-infrared spectrometer to estimate the age of anopheles mosquitoes exposed to pyrethroids.

    Directory of Open Access Journals (Sweden)

    Maggy T Sikulu

    Full Text Available We report on the accuracy of using near-infrared spectroscopy (NIRS to predict the age of Anopheles mosquitoes reared from wild larvae and a mixed age-wild adult population collected from pit traps after exposure to pyrethroids. The mosquitoes reared from wild larvae were estimated as <7 or ≥7 d old with an overall accuracy of 79%. The age categories of Anopheles mosquitoes that were not exposed to the insecticide papers were predicted with 78% accuracy whereas the age categories of resistant, susceptible and mosquitoes exposed to control papers were predicted with 82%, 78% and 79% accuracy, respectively. The ages of 85% of the wild-collected mixed-age Anopheles were predicted by NIRS as ≤8 d for both susceptible and resistant groups. The age structure of wild-collected mosquitoes was not significantly different for the pyrethroid-susceptible and pyrethroid-resistant mosquitoes (P = 0.210. Based on these findings, NIRS chronological age estimation technique for Anopheles mosquitoes may be independent of insecticide exposure and the environmental conditions to which the mosquitoes are exposed.

  18. Mid-Infrared Spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 1. Determination of the Mean Temperature Structure of the Upper Troposphere and Stratosphere

    CERN Document Server

    Orton, Glenn S; Moses, Julianne I; Mainzer, Amy K; Hines, Dean; Hammel, Heidi B; Martin-Torres, F Javier; Burgdorf, Martin; Merlet, Cecile; Line, Michael R

    2014-01-01

    On 2007 December 16-17, spectra were acquired of the disk of Uranus by the Spitzer Infrared Spectrometer (IRS) when its equator was close to the sub-earth point. This spectrum provides the highest-resolution broad-band spectrum ever obtained for Uranus from space, allowing a determination of the disk-averaged temperature and molecule composition to a greater degree of accuracy than ever before. The temperature profiles derived from the Voyager radio occultation experiments that match these data best are those that assume a high abundance of methane in the deep atmosphere, but none of these models provides a satisfactory fit over the full spectral range. This be the result of spatial differences between global and low-latitudinal regions, changes in time, missing continuum opacity sources such as stratospheric hazes or unknown tropospheric constituents, or undiagnosed systematic problems with either the radio-occultation or the Spitzer IRS data sets. The spectrum is compatible with the stratospheric temperatur...

  19. Near-Infrared Photometry of Irregular Satellites of Jupiter and Saturn

    CERN Document Server

    Grav, T; Grav, Tommy; Holman, Matthew J.

    2003-01-01

    We present JHKs photometry of 10 Jovian and 4 Saturnian irregular satellites, taken with the Near-InfraRed Imager (NIRI) at the 8-m Gemini North Observatory on Mauna Kea, Hawaii. The observed objects have near-infrared colors consistent with C, P and D-type asteroids, although J XII Ananke and S IX Phoebe show weak indications of possible water features in the H filter. The four members of the Himalia-family have similar near-infrared colors, as do the two members of the Gallic family, S XX Paaliaq and S XXIX Siarnaq. From low resolution normalized reflectance spectra based on the broadband colors and covering 0.4 to 2.2 microns, the irregular satellites are identified as C-type (J VII Pasiphae, J VI Himalia and S IX Phoebe), P-type (J XII Ananke and J XVIII Themisto) and D-type (J IX Carme and J X Sinope), showing a diversity of origins of these objects.

  20. CLOUD AND HAZE IN THE WINTER POLAR REGION OF TITAN OBSERVED WITH VISUAL AND INFRARED MAPPING SPECTROMETER ON BOARD CASSINI

    Energy Technology Data Exchange (ETDEWEB)

    Rannou, P. [GSMA, UMR CNRS 7331, Universite de Reims Champagne-Ardenne (France); Le Mouelic, S. [LPGN, UMR CNRS 6112, Universite de Nantes (France); Sotin, C. [JPL, California Institute of Technology, PA (United States); Brown, R. H., E-mail: pascal.rannou@univ-reims.fr [LPL, University of Arizona, Tucson, AZ (United States)

    2012-03-20

    A large cloud in the north polar region of Titan was first observed by the Visual and Infrared Mapping Spectrometer (VIMS) in 2005 and then in 2006. This cloud, confined beyond the latitude 62 Degree-Sign N, is surrounded by a mixture of aerosol and mist probably lying in the low stratosphere and troposphere. Subsequent images of this region of Titan show a gradual vanishing of this cloud which was reported previously. In this paper, we characterize the physical properties of this cloud, haze, and mist as well as their time evolutions. We note several details on the images such as a secondary cloud above the main cloud and latitudes beyond 70 Degree-Sign N. We also show that the cloud disappearance leaves the polar region poorly loaded in aerosols, yielding an annular zone of aerosols between 50 Degree-Sign N and 65 Degree-Sign N. Our analysis suggests that this structure observed by VIMS in the near-IR is an annular structure observed by ISS on board Voyager one Titan year ago in 1980.

  1. Using an extractive Fourier transform infrared spectrometer for improving cleanroom air quality in a semiconductor manufacturing plant.

    Science.gov (United States)

    Li, Shou-Nan; Chang, Chin-Ta; Shih, Hui-Ya; Tang, Andy; Li, Alen; Chen, Yin-Yung

    2003-01-01

    A mobile extractive Fourier transform infrared (FTIR) spectrometer was successfully used to locate, identify, and quantify the "odor" sources inside the cleanroom of a semiconductor manufacturing plant. It was found that ozone (O(3)) gas with a peak concentration of 120 ppm was unexpectedly releasing from a headspace of a drain for transporting used ozonized water and that silicon tetrafluoride (SiF(4)) with a peak concentration of 3 ppm was off-gassed from silicon wafers after dry-etching processing. When the sources of the odors was pinpointed by the FTIR, engineering control measures were applied. For O(3) control, a water-sealed pipeline was added to prevent the O(3) gas (emitting from the ozonized water) from entering the mixing unit. A ventilation system also was applied to the mixing unit in case of O(3) release. For SiF(4) mitigation, before the wafer-out chamber was opened, N(2) gas with a flow rate of 150 L/min was used for 100 sec to purge the wafer-out chamber, and a vacuum system was simultaneously activated to pump away the purging N(2). The effectiveness of the control measures was assured by using the FTIR. In addition, the FTIR was used to monitor the potential hazardous gas emissions during preventative maintenance of the semiconductor manufacturing equipment.

  2. Optical Design of a Broadband Infrared Spectrometer for Bunch Length Measurement at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Kiel; /SLAC

    2012-09-07

    The electron pulses generated by the Linac Coherent Light Source at the SLAC National Accelerator Laboratory occur on the order of tens of femtoseconds and cannot be directly measured by conventional means. The length of the pulses can instead be reconstructed by measuring the spectrum of optical transition radiation emitted by the electrons as they move toward a conducting foil. Because the emitted radiation occurs in the mid-infrared from 0.6 to 30 microns a novel optical layout is required. Using a helium-neon laser with wavelength 633 nm, a series of gold-coated off-axis parabolic mirrors were positioned to direct a beam through a zinc selenide prism and to a focus at a CCD camera for imaging. Constructing this layout revealed a number of novel techniques for reducing the aberrations introduced into the system by the off-axis parabolic mirrors. The beam had a recorded radius of less than a millimeter at its final focus on the CCD imager. This preliminary setup serves as a model for the spectrometer that will ultimately measure the LCLS electron pulse duration.

  3. Applicability of a Diffuse Reflectance Infrared Fourier Transform handheld spectrometer to perform in situ analyses on Cultural Heritage materials.

    Science.gov (United States)

    Arrizabalaga, Iker; Gómez-Laserna, Olivia; Aramendia, Julene; Arana, Gorka; Madariaga, Juan Manuel

    2014-08-14

    This work studies the applicability of a Diffuse Reflectance Infrared Fourier Transform handheld device to perform in situ analyses on Cultural Heritage assets. This portable diffuse reflectance spectrometer has been used to characterise and diagnose the conservation state of (a) building materials of the Guevara Palace (15th century, Segura, Basque Country, Spain) and (b) different 19th century wallpapers manufactured by the Santa Isabel factory (Vitoria-Gasteiz, Basque Country, Spain) and by the well known Dufour and Leroy manufacturers (Paris, France), all of them belonging to the Torre de los Varona Castle (Villanañe, Basque Country, Spain). In all cases, in situ measurements were carried out and also a few samples were collected and measured in the laboratory by diffuse reflectance spectroscopy (DRIFT) in order to validate the information obtained by the handheld instrument. In the analyses performed in situ, distortions in the diffuse reflectance spectra can be observed due to the presence of specular reflection, showing the inverted bands caused by the Reststrahlen effect, in particular on those IR bands with the highest absorption coefficients. This paper concludes that the results obtained in situ by a diffuse reflectance handheld device are comparable to those obtained with laboratory diffuse reflectance spectroscopy equipment and proposes a few guidelines to acquire good spectra in the field, minimising the influence caused by the specular reflection.

  4. Infrared absorption of gaseous CH2BrOO detected with a step-scan Fourier-transform absorption spectrometer.

    Science.gov (United States)

    Huang, Yu-Hsuan; Lee, Yuan-Pern

    2014-10-28

    CH2BrOO radicals were produced upon irradiation, with an excimer laser at 248 nm, of a flowing mixture of CH2Br2 and O2. A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to record temporally resolved infrared (IR) absorption spectra of reaction intermediates. Transient absorption with origins at 1276.1, 1088.3, 961.0, and 884.9 cm(-1) are assigned to ν4 (CH2-wagging), ν6 (O-O stretching), ν7 (CH2-rocking mixed with C-O stretching), and ν8 (C-O stretching mixed with CH2-rocking) modes of syn-CH2BrOO, respectively. The assignments were made according to the expected photochemistry and a comparison of observed vibrational wavenumbers, relative IR intensities, and rotational contours with those predicted with the B3LYP/aug-cc-pVTZ method. The rotational contours of ν7 and ν8 indicate that hot bands involving the torsional (ν12) mode are also present, with transitions 7(0)(1)12(v)(v) and 8(0)(1)12(v)(v), v = 1-10. The most intense band (ν4) of anti-CH2BrOO near 1277 cm(-1) might have a small contribution to the observed spectra. Our work provides information for directly probing gaseous CH2BrOO with IR spectroscopy, in either the atmosphere or laboratory experiments.

  5. Infrared absorption of gaseous CH2BrOO detected with a step-scan Fourier-transform absorption spectrometer

    Science.gov (United States)

    Huang, Yu-Hsuan; Lee, Yuan-Pern

    2014-10-01

    CH2BrOO radicals were produced upon irradiation, with an excimer laser at 248 nm, of a flowing mixture of CH2Br2 and O2. A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to record temporally resolved infrared (IR) absorption spectra of reaction intermediates. Transient absorption with origins at 1276.1, 1088.3, 961.0, and 884.9 cm-1 are assigned to ν4 (CH2-wagging), ν6 (O-O stretching), ν7 (CH2-rocking mixed with C-O stretching), and ν8 (C-O stretching mixed with CH2-rocking) modes of syn-CH2BrOO, respectively. The assignments were made according to the expected photochemistry and a comparison of observed vibrational wavenumbers, relative IR intensities, and rotational contours with those predicted with the B3LYP/aug-cc-pVTZ method. The rotational contours of ν7 and ν8 indicate that hot bands involving the torsional (ν12) mode are also present, with transitions 7_0^1 12_v^v and 8_0^1 12_v^v, v = 1-10. The most intense band (ν4) of anti-CH2BrOO near 1277 cm-1 might have a small contribution to the observed spectra. Our work provides information for directly probing gaseous CH2BrOO with IR spectroscopy, in either the atmosphere or laboratory experiments.

  6. Observations in the Saturn system during approach and orbital insertion, with Cassini's visual and infrared mapping spectrometer (VIMS)

    Science.gov (United States)

    Brown, R.H.; Baines, K.H.; Bellucci, G.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Formisano, V.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, C.; Baugh, N.; Griffith, C.A.; Hansen, G.B.; Hibbitts, C.A.; Momary, T.W.; Showalter, M.R.

    2006-01-01

    The Visual and Infrared Mapping Spectrometer observed Phoebe, Iapetus, Titan and Saturn's rings during Cassini's approach and orbital insertion. Phoebe's surface contains water ice, CO2, and ferrous iron. lapetus contains CO2 and organic materials. Titan's atmosphere shows methane fluorescence, and night-side atmospheric emission that may be CO2 and CH3D. As determined from cloud motions, the winds at altitude 25-30 km in the south polar region of Titan appear to be moving in a prograde direction at velocity ???1 m s-1. Circular albedo features on Titan's surface, seen at 2.02 ??m, may be palimpsests remaining from the rheological adjustment of ancient impact craters. As such, their long-term persistence is of special interest in view of the expected precipitation of liquids and solids from the atmosphere. Saturn's rings have changed little in their radial structure since the Voyager flybys in the early 1980s. Spectral absorption bands tentatively attributed to Fe2+ suggest that iron-bearing silicates are a source of contamination of the C ring and the Cassini Division. ?? ESO 2006.

  7. [Miniature near-infrared fibre optic spectrometer for the quantitative detection of protein and fat in milk powder].

    Science.gov (United States)

    Zhang, Zhong-Wei; Wen, Zhi-Yu; Zeng, Tian-Ling; Wei, Kang-Lin; Liang, Yu-Qian

    2013-07-01

    The method based on miniature near-infrared spectrometer combined with Y fiber optic probe to detect the protein and fat in milk powder by diffuse reflectance spectroscopy in the wavelength range of 900-1 700 nm was proposed. By selecting the appropriate spectral bands, the correction models of protein and fat were established with partial least squares algorithm using Unscrambler 9.7 Chemometrics software. The determination coefficients R2 of the correction modes are 0.987 and 0.986 for protein and fat respectively, and the root mean square errors RMSEC are 0.385 and 0.419 respectively. Using these correction models to predict the protein and fat contents with 30 sets of forecast sample data, the prediction standard deviation is SEP(Protein) = 0.751 for protein, and is SEP(Fat) = 1.109 for fat. The results indicate that these correction models have prediction capability with unknown samples and meet the on line requirements.

  8. Near-infrared photometry and astrometry of Neptune's inner satellites and ring-arcs

    Science.gov (United States)

    Dumas, C.; Terrile, R. J.; Smith, B. A.; Schneider, G.; Becklin, E. E.

    2000-10-01

    Until recently, the system of Neptune's inner satellites and ring-arcs had only been observed in direct imaging from the Voyager 2 spacecraft, limiting our knowledge of this system to visible wavelengths data. Nearly ten years after the Voyager fly-by, HST/NICMOS observed the close vicinity of Neptune at 1.87μ m, a wavelength that corresponds to a strong methane absorption in the atmosphere of Neptune and allows the attenuation of the scattered light produced by the planet. We derived the near-infrared geometric albedo of the ring-arcs and small moons Proteus, Larissa, Galatea and Despina, and compared their orbital positions with the predictions from the 1989 Voyager observations. The surfaces of the inner satellites of Neptune appear to be coated with dark, neutral material, with albedoes ranging from 0.077 (Proteus) to 0.033 (Despina) and their orbital position was found to be within the prediction errors of the Voyager measurements. The material located inside the ring-arcs of Neptune also displays a low-neutral reflectance (p{1.87 μm } ~ 0.055) and the HST/NICMOS measurement of the mean orbital motion of the ring-arcs shows that their confinement cannot be entirely explained by resonances produced by the nearby satellite Galatea (Nature, 400, 733-735). This work was performed at the Jet Propulsion Laboratory, Caltech, under contract with the National Aeronautics and Space Administration, and is supported by NASA grant NAG5-3042.

  9. A Multi-Channel THz and Infrared Spectrometer for Femtosecond Electron Bunch Diagnostics by Single-Shot Spectroscopy of Coherent Radiation

    CERN Document Server

    Wesch, S; Behrens, C; Delsim-Hashemi, H; Schmüser, P

    2011-01-01

    The high peak current required in free-electron lasers (FELs) is realized by longitudinal compression of the electron bunches to sub-picosecond length. In this paper, a frequency-domain diagnostic method is described that is capable of resolving structures in the femtosecond regime. A novel in-vacuum spectrometer has been developed for spectroscopy of coherent radiation in the THz and infrared range. The spectrometer is equipped with five consecutive dispersion gratings and 120 parallel readout channels; it can be operated either in short wavelength mode (5 - 44 um) or in long wavelength mode (45 - 430 um). Fast parallel readout permits the spectroscopy of coherent radiation from single electron bunches. Test measurements at the soft X-ray free-electron laser FLASH, using coherent transition radiation, demonstrate excellent performance of the spectrometer. The high sensitivity down to a few micrometers allows study of short bunch features caused for example by microbunching effects in magnetic chicanes. The d...

  10. Mimir: A Near-Infrared Wide-Field Imager, Spectrometer and Polarimeter

    Science.gov (United States)

    Clemens, D. P.; Sarcia, D.; Grabau, A.; Tollestrup, E. V.; Buie, M. W.; Dunham, E.; Taylor, B.

    2007-12-01

    Mimir, a new facility-class near-infrared instrument for the 1.8 m Perkins telescope on Anderson Mesa outside Flagstaff, Arizona, was commissioned and has been operating for three years. Mimir is multifunction, performing wide-field (F/5) and narrow-field (F/17) imaging, long-slit spectroscopy, and imaging polarimetry. The F/5 mode images at 0.59" per pixel onto the 1024 × 1024 pixel ALADDIN III InSb array detector, giving a 10' × 10' field of view. In the F/17 mode, the plate scale is 0.18" per pixel. Optically, Mimir is a refractive reimager for the F/17.5 Perkins beam. A six-lens collimator produces an achromatic 25 mm pupil, which is imaged by a five-lens camera (F/5), a four-lens camera (F/17), or a two-lens pupil viewer onto the detector. Three filter wheels precede the pupil, one follows the pupil. The wheels contain a rotating half-wave plate, broadband filters, narrowband filters, grisms, long-pass filters, a wire grid, and thermal IR blockers. The first telescope focus is within Mimir, where a slit and decker unit, consisting of two linear motion cars, selects one of 13 slit scenes. The slit and decker cars, the four filter wheels, the half-wave plate rotation, and the camera selector are all driven by stepper motors within the cold vacuum space. Cooling is provided by a CTI 1050 two-stage, closed-cycle helium refrigerator, keeping the optics, filters, and internal surfaces between 65 and 75 K and the detector at 33.5 K. Switching between Mimir's different modes takes only a few seconds, making it a versatile tool for conducting a wide range of investigations and for quickly reacting to changing observing conditions. Mimir on the Perkins telescope achieves imaging sensitivities 2-4 mag deeper than 2MASS, moderate resolution (R ˜ 700) JHK spectra of virtually any 2MASS source, high-precision wide-field imaging polarimetry, and L' and M' band imaging and spectroscopy.

  11. For geological investigations with airborne thermal infrared multispectral images: Transfer of calibration from laboratory spectrometer to TIMS as alternative for removing atmospheric effects

    Science.gov (United States)

    Edgett, Kenneth S.; Anderson, Donald L.

    1995-01-01

    This paper describes an empirical method to correct TIMS (Thermal Infrared Multispectral Scanner) data for atmospheric effects by transferring calibration from a laboratory thermal emission spectrometer to the TIMS multispectral image. The method does so by comparing the laboratory spectra of samples gathered in the field with TIMS 6-point spectra for pixels at the location of field sampling sites. The transference of calibration also makes it possible to use spectra from the laboratory as endmembers in unmixing studies of TIMS data.

  12. Characterization of the 3D distribution of ozone and coarse aerosols in the Troposphere using IASI thermal infrared satellite observations

    Science.gov (United States)

    Cuesta, J.; Eremenko, M.; Dufour, G.; Hoepfner, M.; Orphal, J.

    2012-04-01

    Both tropospheric ozone and aerosols significantly affect air quality in megacities during pollution events. Moreover, living conditions may be seriously aggravated when such agglomerations are affected by wildfires (e.g. Russian fires over Moscow in 2010), which produce smoke and pollutant precursors, or even during dense desert dust outbreaks (e.g. recurrently over Beijing or Cairo). Moreover, since aerosols diffuse and absorb solar radiation, they have a direct impact on the photochemical production of tropospheric ozone. These interactions during extreme events of high aerosol loads are nowadays poorly known, even though they may significantly affect the tropospheric photochemical equilibrium. In order to address these issues, we have developed a new retrieval technique to jointly characterize the 3D distribution of both tropospheric ozone and coarse aerosols, using spaceborne observations of the infrared spectrometer IASI onboard MetOp-A satellite. Our methodology is based on the inversion of Earth radiance spectra in the atmospheric window from 8 to 12 μm measured by IASI and a «Tikhonov-Philipps»-type regularisation with constraints varying in altitude (as in [Eremenko et al., 2008, GRL; Dufour et al., 2010 ACP]) to simultaneously retrieve ozone profiles, aerosol optical depths at 10 μm and aerosol layer effective heights. Such joint retrieval prevents biases in the ozone profile retrieval during high aerosol load conditions. Aerosol retrievals using thermal infrared radiances mainly account for desert dust and the coarse fraction of biomass burning aerosols. We use radiances from 15 micro-windows within the 8-12 μm atmospheric window, which were carefully chosen (following [Worden et al., 2006 JGR]) for extracting the maximum information on aerosols and ozone and minimizing contamination by other species. We use the radiative transfer code KOPRA, including line-by-line calculations of gas absorption and single scattering for aerosols [Hoepfner et al

  13. Details of assessing information content of the Tropospheric Infrared Mapping Spectrometers (TIMS) GEO-CAPE instrument concept when applied for several infrared ozone bands

    Science.gov (United States)

    Rairden, R. L.; Kumer, J. B.; Roche, A. E.; Desouza-Machado, S. G.; Chatfield, R. B.; Blatherwick, R.

    2009-12-01

    With support of NASA ESTO Instrument Incubator Program (IIP) Tropospheric Infrared Mapping Spectrometers (TIMS) have been demonstrated for multi-layer retrieval of Atmospheric CO. Two TIMS units operating in spectral regions centered at 2.33 and 4.68 µm were developed for this demonstration. Here we present the details of scaling the characteristics of the demonstration measurements including spectral range, sample spacing and resolution, and noise per sample to the scenario of GEO-CAPE mission and to several additional wave length regions. This includes the detail of expanding to more than two spectral regions. It includes an example of scaling the noise as demonstrated by the demonstration measurements to the space case, and to other spectral regions. Common with our oral presentation, methods based on these scaled instrument characteristics for estimating vertical information content are reviewed. The methods are applied and estimated vertical information content of measurements in ozone bands near 9.4, 4.7, 3.6 and 3.3 µm and in various combinations of these bands is presented. A simple simultaneous retrieval of humidity and ozone from atmospheric spectral absorption data in the 3.3 and 3.6 µm regions that was obtained by a solar viewing FTS is briefly presented. This is partially analogous to the retrieval of ozone from the earth’s surface diffuse reflection of sunlight as viewed from space. It supports the premise that these space borne measurements can contribute to the quality of the GEO-CAPE ozone measurements.

  14. Mapped minerals at Questa, New Mexico, using airborne visible-infrared imaging spectrometer (AVIRIS) data -- Preliminary report

    Science.gov (United States)

    Livo, K. Eric; Clark, Roger N.

    2002-01-01

    This preliminary study for the First Quarterly Report has spectrally mapped hydrothermally altered minerals useful in assisting in assessment of water quality of the Red River. Airborne Visible-Infrared Imaging Spectrometer (AVIRIS) data was analyzed to characterize mined and unmined ground at Questa, New Mexico. AVIRIS data covers the Red River drainage north of the river, from between the town of Questa on the west, to east of the town of Red River. The data was calibrated and analyzed using U.S. Geological Survey custom software and spectral mineral library. AVIRIS data was tested for spectral features that matched similar features in the spectral mineral library. Goodness-of-fit and band-depth were calculated for each comparison of spectral features and used to identify surface mineralogy. Mineral distribution, mineral associations, and AVIRIS pixel spectra were examined. Mineral maps show the distribution of iron hydroxides, iron sulfates, clays, micas, carbonates, and other minerals. Initial results show a system of alteration suites that overprint each other. Quartz-sericite-pyrite (QSP) alteration grading out to propylitic alteration (epidote and calcite) was identified at the Questa Mine (molybdenum porphyry) and a similar alteration pattern was mapped at the landslide (?scar?) areas. Supergene weathering overprints the altered rock, as shown by jarosite, kaolinite, and gypsum. In the spectral analysis, hydrothermally altered ground appears to be more extensive at the unmined Goat Hill Gulch and the mined ground, than the ?scars? to the east. Though the ?scars? have similar overall altered mineral suites, there are differences between the ?scars? in sericite, kaolinite, jarosite, gypsum, and calcite abundance. Fieldwork has verified the results at the central unmined ?scar? areas.

  15. Retrieval algorithm for CO2 and CH4 column abundances from short-wavelength infrared spectral observations by the Greenhouse Gases Observing Satellite

    Directory of Open Access Journals (Sweden)

    I. Morino

    2010-11-01

    Full Text Available The Greenhouse gases Observing SATellite (GOSAT was launched on 23 January 2009 to monitor the global distributions of carbon dioxide and methane from space. It has operated continuously since then. Here we describe a retrieval algorithm for column abundances of these gases from the short-wavelength infrared spectra obtained by the Thermal And Near infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS. The algorithm consists of three steps. First, cloud-free observational scenes are selected by several cloud-detection methods. Then, column abundances of carbon dioxide and methane are retrieved based on the optimal estimation method. Finally, the retrieval quality is examined to exclude low-quality and/or aerosol-contaminated results. Most of the retrieval random errors come from the instrumental noise. The interferences by auxiliary parameters retrieved simultaneously with gas abundances are small. The evaluated precisions of the retrieved column abundances for single observations are less than 1% in most cases. The interhemispherical differences and the temporal variation patterns of the retrieved column abundances agree well with the current state of knowledge.

  16. Retrieval algorithm for CO2 and CH4 column abundances from short-wavelength infrared spectral observations by the Greenhouse gases observing satellite

    Directory of Open Access Journals (Sweden)

    I. Morino

    2011-04-01

    Full Text Available The Greenhouse gases Observing SATellite (GOSAT was launched on 23 January 2009 to monitor the global distributions of carbon dioxide and methane from space. It has operated continuously since then. Here, we describe a retrieval algorithm for column abundances of these gases from the short-wavelength infrared spectra obtained by the Thermal And Near infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS. The algorithm consists of three steps. First, cloud-free observational scenes are selected by several cloud-detection methods. Then, column abundances of carbon dioxide and methane are retrieved based on the optimal estimation method. Finally, the retrieval quality is examined to exclude low-quality and/or aerosol-contaminated results. Most of the retrieval random errors come from instrumental noise. The interferences due to auxiliary parameters retrieved simultaneously with gas abundances are small. The evaluated precisions of the retrieved column abundances for single observations are less than 1% in most cases. The interhemispherical differences and temporal variation patterns of the retrieved column abundances show features similar to those of an atmospheric transport model.

  17. Probable satellite thermal infrared anomaly before the Zhangbei MS=6.2 earthquake on January 10, 1998

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper used the thermal infrared data of the satellite NOAA-AAVHRR of the north part of North China (113°~119° E, 38°~42° N), and processed the remote sensing data through radiation adjustment, geometric adjustment and so on by the software "The Monitoring and Fast Process System of Earthquake Precursor Thermal Infrared Anomaly", inversed the earth surface temperature. Some disturbances effect had been excluded, and thermal infrared temperature anomaly had been extracted by the picture difference method. The Zhangbei MS=6.2 earthquake is used as the example in the paper, so that in the paper thermal infrared characteristics on time-space before earthquake and the relationship between the anomaly and the earthquake prediction have been summarized.Within more than ten days before the Zhangbei earthquake, the thermal infrared anomaly had emerged widely along Zhangjiakou-Bohai seismic belt, and the anomalous region seemed like a belt and it is also consistent with the tectonic background there; the anomaly expanded from the outside toward the earthquake focus, but the focus lay at the edge of the thermal infrared region. So it is possible to explore a new anomaly observation method for earthquake prediction by observing and studying the satellite thermal infrared anomaly before big earthquakes happen.

  18. Tropospheric Emission Spectrometer (TES) Satellite Validations of Ammonia, Methanol, Formic Acid, and Carbon Monoxide over the Canadian Oil Sands

    Data.gov (United States)

    U.S. Environmental Protection Agency — The URLs link to the data archive of the Troposphere Emission Spectrometer (TES) retrievals. These include the transects included in the Canadian Tar Sands study. A...

  19. Report of the Joint Scientific Mission Definition Team for an infrared astronomical satellite

    Science.gov (United States)

    1976-01-01

    The joint effort is reported of scientists and engineers from the Netherlands, the United Kingdom, and the United States working as a team for the purpose of exploring the possibility of a cooperative venture. The proposed mission builds upon experience gained from the successful Astronomical Netherlands Satellite (ANS). This satellite will be in a polar orbit at an altitude of 900 km. It will carry an 0.6 m diameter telescope cooled with helium to a temperature near 10K. An array of approximately 100 detectors will be used to measure the infrared flux in four wavelength bands centered at 10, 20, 50, and 100 microns. Sources will be located on the sky with positional accuracy of 1/2 arcminute. The instrument should be able to investigate the structure of extended sources with angular scales up to 1.0 deg. The entire sky will be surveyed and the full lifetime of the mission of about one year will be necessary to complete the survey. Special observational programs will also be incorporated into the mission.

  20. Ground-based Measurements of Vertical Profiles and Columns of Atmospheric Trace Gases Over Toronto Using a New High-Resolution Fourier Transform Infrared Spectrometer

    Science.gov (United States)

    Wiacek, A.; Yashcov, D.; Strong, K.; Boudreau, L.; Rochette, L.; Roy, C.

    2002-12-01

    The University of Toronto Atmospheric Observatory (TAO) has recently been established at Toronto, Canada. TAO includes several instruments, with a DA8 Fourier Transform Spectrometer (DA8 FTS, manufactured by ABB Bomem Inc., Québec, Canada) serving as the primary instrument at the facility. The geographic position of TAO (43.66°N, 79.40°W) makes it well suited for long-term measurements of mid-latitude stratospheric ozone and related species, while its urban setting enables measurements of tropospheric pollution. The DA8 FTS is based on a Michelson interferometer with a maximum optical path difference of 250 cm, providing a maximum unapodized resolution of 0.0026 cm-1. It is currently equipped with KBr and CaF2 beamsplitters, and InSb and HgCdTe detectors, for coverage of the spectral range from 700 to 4100 cm-1. A new heliostat (manufactured by Aim Controls Inc., California, USA) provides active solar tracking, collecting the incoming solar radiation and directing it into the FTS. The TAO DA8 FTS incorporates a new optical design recently developed by ABB Bomem Inc., which results in a fixed optical axis through the beamsplitter (and a fixed focal point on the detector) as well as a more stable modulation efficiency. The new instrument optics will be discussed. Next, the performance of the instrument will be examined in the context of standard NDSC (Network for the Detection of Stratospheric Change) trace gas column and vertical profile retrieval techniques, which use least squares fitting algorithms (SFIT, SFIT2). TAO has been operational (weather permitting) since October 2001. We have been retrieving columns and vertical profiles of HCl, HF, CH4, OCS, C2H6, CO, N2O and NO2 since May 2002. A detailed error analysis of retrieved columns and vertical profiles has been undertaken for the above species. Future plans for the TAO FTS include comparing our measurements with satellite measurements made by MOPITT, OSIRIS, and the upcoming ACE and MAESTRO instruments

  1. The Compact High Resolution Imaging Spectrometer (CHRIS): the future of hyperspectral satellite sensors. Imagery of Oostende coastal and inland waters

    OpenAIRE

    B. De Mol; Ruddick, K

    2004-01-01

    The gap between airborne imaging spectroscopy and traditional multi spectral satellite sensors is decreasing thanks to a new generation of satellite sensors of which CHRIS mounted on the small and low-cost PROBA satellite is the prototype. Although image acquisition and analysis are still in a test phase, the high spatial and spectral resolution and pointability have proved their potential. Because of the high resolution small features, which were before only visible on airborne images, becom...

  2. An airborne infrared laser spectrometer for in-situ trace gas measurements: application to tropical convection case studies

    Directory of Open Access Journals (Sweden)

    V. Catoire

    2015-09-01

    Full Text Available A three-channel laser absorption spectrometer called SPIRIT (SPectromètre InfraRouge In situ Toute altitude has been developed for airborne measurements of trace gases in the troposphere and lower stratosphere. More than three different species can be measured simultaneously with high time resolution (each 1.6 s using three individual CW-DFB-QCLs (Continuous Wave Distributed FeedBack Quantum Cascade Lasers coupled to a single Robert multipass optical cell. The lasers are operated in a time-multiplexed mode. Absorption of the mid-infrared radiations occur in the cell (2.8 L with effective path lengths of 134 to 151 m at reduced pressure, with detection achieved using a HgCdTe detector cooled by Stirling cycle. The performances of the instrument are described, in particular precisions of 1, 1 and 3 %, and volume mixing ratio (vmr sensitivities of 0.4, 6 and 2.4 ppbv are determined at 1.6 s for CO, CH4 and N2O, respectively (at 1σ confidence level. Estimated accuracies without calibration are about 6 %. Dynamic measuring ranges of about four decades are established. The first deployment of SPIRIT was realized aboard the Falcon-20 research aircraft operated by DLR (Deutsches Zentrum für Luft- und Raumfahrt within the frame of the SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere European project in November-December 2011 over Malaysia. The convective outflows from two large convective systems near Borneo Island (6.0° N–115.5° E and 5.5° N–118.5° E were sampled above 11 km in altitude on 19 November and 9 December, respectively. Correlated enhancements in CO and CH4 vmr were detected when the aircraft crossed the outflow anvil of both systems. These enhancements were interpreted as the fingerprint of transport from the boundary layer up through the convective system and then horizontal advection in the outflow. Using these observations, the fraction of boundary layer air contained in fresh convective outflow was

  3. An Autonomous System to Take Angular Thermal-Infrared Measurements for Validating Satellite Products

    Directory of Open Access Journals (Sweden)

    Raquel Niclòs

    2015-11-01

    Full Text Available An autonomous system for field land surface temperature (LST measurements taken at different observation angles was developed to be deployed easily at any conventional meteorological tower station. The system permits ground-truth data to be acquired on a continuous basis, and angularly scans land and sky hemispheres with a single thermal-infrared (TIR radiometer. This paper describes the autonomous angular system and the methodology to assess ground-truth LST and relative-to-nadir emissivity data from system measurements. Ground-truth LSTs were used to validate satellite-retrieved LST products at two experimental sites (rice crop and shrubland areas. The relative-to-nadir emissivity values were used to analyze the anisotropy of surface emissive properties over thermally-homogeneous covers. The EOS-MODIS MOD11_L2/MYD11_L2 LST product was evaluated and shown to work within expected uncertainties (<2.0 K when tested against the system data. A slight underestimation of around −0.15 K was observed, which became greater for the off-nadir observation angles at the shrubland site. The system took angular measurements for the different seasonal homogeneous covers at the rice crop site. These measurements showed emissivity angular anisotropies, which were in good agreement with previously published data. The dual-view ENVISAT-AATSR data reproduced them, and revealed that the system data collected for thermally-homogeneous surfaces could be used to test future satellite TIR sensors with multi-angular or bi-angular capabilities, like the forthcoming SLSTR on board Copernicus Sentinel-3A.

  4. Comparison of Two Methodologies for Calibrating Satellite Instruments in the Visible and Near-Infrared

    Science.gov (United States)

    Barnes, Robert A.; Brown, Steven W.; Lykke, Keith R.; Guenther, Bruce; Butler, James J.; Schwarting, Thomas; Turpie, Kevin; Moyer, David; DeLuccia, Frank; Moeller, Christopher

    2015-01-01

    Traditionally, satellite instruments that measure Earth-reflected solar radiation in the visible and near infrared wavelength regions have been calibrated for radiance responsivity in a two-step method. In the first step, the relative spectral response (RSR) of the instrument is determined using a nearly monochromatic light source such as a lamp-illuminated monochromator. These sources do not typically fill the field-of-view of the instrument nor act as calibrated sources of light. Consequently, they only provide a relative (not absolute) spectral response for the instrument. In the second step, the instrument views a calibrated source of broadband light, such as a lamp-illuminated integrating sphere. The RSR and the sphere absolute spectral radiance are combined to determine the absolute spectral radiance responsivity (ASR) of the instrument. More recently, a full-aperture absolute calibration approach using widely tunable monochromatic lasers has been developed. Using these sources, the ASR of an instrument can be determined in a single step on a wavelength-by-wavelength basis. From these monochromatic ASRs, the responses of the instrument bands to broadband radiance sources can be calculated directly, eliminating the need for calibrated broadband light sources such as lamp-illuminated integrating spheres. In this work, the traditional broadband source-based calibration of the Suomi National Preparatory Project (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) sensor is compared with the laser-based calibration of the sensor. Finally, the impact of the new full-aperture laser-based calibration approach on the on-orbit performance of the sensor is considered.

  5. Quantitative investigations of geologic surfaces utilizing airborne visible/infrared imaging spectrometer (AVIRIS) and polarimetric radar (AIRSAR) data for Death Valley, California

    Science.gov (United States)

    Kierein-Young, Kathryn S.; Kruse, Fred A.

    1991-01-01

    Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and polarimetric radar (AIRSAR) data were collected over Death Valley, California, USA, in September 1989. These two data sets were used to quantitatively characterize both the mineralogy and surface structure of the valley floor. Field mapping and characterization of the salt flats across the valley identified 16 separate units. The AVIRIS data were calibrated using the 'empirical line' method, and spectra extracted for the 16 units. A water vapor map was generated from the AVIRIS data and showed spatial variations in its distribution due to evaporation of surface water. Unmixing of the 16 spectral units produced maps of endmember abundance.

  6. Quantitative investigations of geologic surfaces utilizing airborne visible/infrared imaging spectrometer (AVIRIS) and polarimetric radar (AIRSAR) data for Death Valley, California

    Science.gov (United States)

    Kierein-Young, Kathryn S.; Kruse, Fred A.

    1991-01-01

    Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and polarimetric radar (AIRSAR) data were collected over Death Valley, California, USA, in September 1989. These two data sets were used to quantitatively characterize both the mineralogy and surface structure of the valley floor. Field mapping and characterization of the salt flats across the valley identified 16 separate units. The AVIRIS data were calibrated using the 'empirical line' method, and spectra extracted for the 16 units. A water vapor map was generated from the AVIRIS data and showed spatial variations in its distribution due to evaporation of surface water. Unmixing of the 16 spectral units produced maps of endmember abundance.

  7. Application of satellite infrared data for mapping of thermal plume contamination in coastal ecosystem of Korea.

    Science.gov (United States)

    Ahn, Yu-Hwan; Shanmugam, Palanisamy; Lee, Jae-Hak; Kang, Yong Q

    2006-03-01

    The 5900 MW Younggwang nuclear power station on the west coast of Korea discharges warm water affecting coastal ecology [KORDI report (2003). Wide area observation of the impact of the operation of Younggwang nuclear power plant 5 and 6, No. BSPI 319-00-1426-3, KORDI, Seoul, Korea]. Here the spatial and temporal characteristics of the thermal plume signature of warm water are reported from a time series (1985-2003) of space-borne, thermal infrared data from Landsat and National Oceanic and Atmospheric Administration (NOAA) satellites. Sea surface temperature (SST) were characterized using advanced very high resolution radiometer data from the NOAA satellites. These data demonstrated the general pattern and extension of the thermal plume signature in the Younggwang coastal areas. In contrast, the analysis of SST from thematic mapper data using the Landsat-5 and 7 satellites provided enhanced information about the plume shape, dimension and direction of dispersion in these waters. The thermal plume signature was detected from 70 to 100 km to the south of the discharge during the summer monsoon and 50 to 70 km to the northwest during the winter monsoon. The mean detected plume temperature was 28 degrees C in summer and 12 degrees C in winter. The DeltaT varied from 2 to 4 degrees C in winter and 2 degrees C in summer. These values are lower than the re-circulating water temperature (6-9 degrees C). In addition the temperature difference between tidal flats and offshore (SSTtidal flats - SSToffsore) was found to vary from 5.4 to 8.5 degrees C during the flood tides and 3.5 degrees C during the ebb tide. The data also suggest that water heated by direct solar radiation on the tidal flats during the flood tides might have been transported offshore during the ebb tide. Based on these results we suggest that there is an urgent need to protect the health of Younggwang coastal marine ecosystem from the severe thermal impact by the large quantity of warm water discharged from

  8. Atmospheric influences on infrared-laser signals used for occultation measurements between Low Earth Orbit satellites

    Directory of Open Access Journals (Sweden)

    S. Schweitzer

    2011-10-01

    Full Text Available LEO-LEO infrared-laser occultation (LIO is a new occultation technique between Low Earth Orbit (LEO satellites, which applies signals in the short wave infrared spectral range (SWIR within 2 μm to 2.5 μm. It is part of the LEO-LEO microwave and infrared-laser occultation (LMIO method that enables to retrieve thermodynamic profiles (pressure, temperature, humidity and altitude levels from microwave signals and profiles of greenhouse gases and further variables such as line-of-sight wind speed from simultaneously measured LIO signals. Due to the novelty of the LMIO method, detailed knowledge of atmospheric influences on LIO signals and of their suitability for accurate trace species retrieval did not yet exist. Here we discuss these influences, assessing effects from refraction, trace species absorption, aerosol extinction and Rayleigh scattering in detail, and addressing clouds, turbulence, wind, scattered solar radiation and terrestrial thermal radiation as well. We show that the influence of refractive defocusing, foreign species absorption, aerosols and turbulence is observable, but can be rendered small to negligible by use of the differential transmission principle with a close frequency spacing of LIO absorption and reference signals within 0.5%. The influences of Rayleigh scattering and terrestrial thermal radiation are found negligible. Cloud-scattered solar radiation can be observable under bright-day conditions, but this influence can be made negligible by a close time spacing (within 5 ms of interleaved laser-pulse and background signals. Cloud extinction loss generally blocks SWIR signals, except very thin or sub-visible cirrus clouds, which can be addressed by retrieving a cloud layering profile and exploiting it in the trace species retrieval. Wind can have a small influence on the trace species absorption, which can be made negligible by using a simultaneously retrieved or a moderately accurate background wind speed profile. We

  9. Ozone Profile Retrieval from Satellite Observation Using High Spectral Resolution Infrared Sounding Instrument

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents a preliminary result on the retrieval of atmospheric ozone profiles using an im proved regression technique and utilizing the data from the Atmospheric InfraRed Sounder (AIRS), a hyper-spectral instrument expected to be flown on the EOS-AQUA platform in 2002. Simulated AIRS spectra were used to study the sensitivity of AIRS radiance on the tropospheric and stratospheric ozone changes, and to study the impact of various channel combinations on the ozone profile retrieval. Sensitivity study results indicate that the AIRS high resolution spectral channels between the wavenumber 650- 800 cm-1 provide very useful information to accurately retrieve tropospheric and stratospheric ozone pro files. Eigenvector decomposition of AIRS spectra indicate that no more than 100 eigenvectors are needed to retrieve very accurate ozone profiles. The accuracy of the retrieved atmospheric ozone profile from the pres ent technique and utilizing the AIRS data was compared with the accuracy obtained from current Advanced TIROS Operational Vertical Sounder (ATOVS) data aboard National Oceanic and Atmospheric Admini stration (NOAA) satellites. As expected, a comparison of retrieval results confirms that the ozone profile re trieved with the AIRS data is superior to that of ATOVS.

  10. Use of Real Time Satellite Infrared and Ocean Color to Produce Ocean Products

    Science.gov (United States)

    Roffer, M. A.; Muller-Karger, F. E.; Westhaver, D.; Gawlikowski, G.; Upton, M.; Hall, C.

    2014-12-01

    Real-time data products derived from infrared and ocean color satellites are useful for several types of users around the world. Highly relevant applications include recreational and commercial fisheries, commercial towing vessel and other maritime and navigation operations, and other scientific and applied marine research. Uses of the data include developing sampling strategies for research programs, tracking of water masses and ocean fronts, optimizing ship routes, evaluating water quality conditions (coastal, estuarine, oceanic), and developing fisheries and essential fish habitat indices. Important considerations for users are data access and delivery mechanisms, and data formats. At this time, the data are being generated in formats increasingly available on mobile computing platforms, and are delivered through popular interfaces including social media (Facebook, Linkedin, Twitter and others), Google Earth and other online Geographical Information Systems, or are simply distributed via subscription by email. We review 30 years of applications and describe how we develop customized products and delivery mechanisms working directly with users. We review benefits and issues of access to government databases (NOAA, NASA, ESA), standard data products, and the conversion to tailored products for our users. We discuss advantages of different product formats and of the platforms used to display and to manipulate the data.

  11. A method for retrieving clouds with satellite infrared radiances using the particle filter

    Science.gov (United States)

    Xu, Dongmei; Auligné, Thomas; Descombes, Gaël; Snyder, Chris

    2016-11-01

    Ensemble-based techniques have been widely utilized in estimating uncertainties in various problems of interest in geophysical applications. A new cloud retrieval method is proposed based on the particle filter (PF) by using ensembles of cloud information in the framework of Gridpoint Statistical Interpolation (GSI) system. The PF cloud retrieval method is compared with the Multivariate Minimum Residual (MMR) method that was previously established and verified. Cloud retrieval experiments involving a variety of cloudy types are conducted with the PF and MMR methods with measurements of infrared radiances on multi-sensors onboard both geostationary and polar satellites, respectively. It is found that the retrieved cloud masks with both methods are consistent with other independent cloud products. MMR is prone to producing ambiguous small-fraction clouds, while PF detects clearer cloud signals, yielding closer heights of cloud top and cloud base to other references. More collections of small-fraction particles are able to effectively estimate the semi-transparent high clouds. It is found that radiances with high spectral resolutions contribute to quantitative cloud top and cloud base retrievals. In addition, a different way of resolving the filtering problem over each model grid is tested to better aggregate the weights with all available sensors considered, which is proven to be less constrained by the ordering of sensors. Compared to the MMR method, the PF method is overall more computationally efficient, and the cost of the model grid-based PF method scales more directly with the number of computing nodes.

  12. The Critical Need for Future Mid-Resolution Thermal Infrared Satellite Sensors

    Science.gov (United States)

    Vincent, R. K.

    2006-12-01

    Eight future applications of data from mid-resolution thermal infrared satellite sensors are suggested, from least to most significant as follows: 8. Map thin ice unsafe for ice-fishing in the Great Lakes as a warning to winter fishermen; 7. Map ammonia plumes to locate large ammonia stockpiles (Homeland Security) and to monitor concentrated animal feeding operations (CAFOs); 6. Map types of surface algae in ocean, lakes, and rivers, especially those containing surface diatoms; 5. Monitor urban heat islands to determine the cooling affects of painting visibly dark surfaces with bright paints or coatings; 4. Map rock-types and soil-types of non- vegetated regions world-wide, a task which ASTER cannot complete in its current lifetime; 3. Detect surface warming of rocks under increased stress and pressure as an earthquake precursor; 2. Map pollutant gases, especially sulfur dioxide, which is important both for smokestack monitoring and volcanic eruption precursors; 1. Map methane escape into the atmosphere from methane clathrate destabilization as a key warning of imminent and drastic temperature rises in the troposphere. Each of these applications will be briefly discussed and past examples will be given for most of them.

  13. A multi-channel THz and infrared spectrometer for femtosecond electron bunch diagnostics by single-shot spectroscopy of coherent radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wesch, Stephan; Schmidt, Bernhard; Behrens, Christopher; Delsim-Hashemi, Hossein; Schmueser, Peter

    2011-08-15

    The high peak current required in free-electron lasers (FELs) is realized by longitudinal compression of the electron bunches to sub-picosecond length. In this paper, a frequency-domain diagnostic method is described that is capable of resolving structures in the femtosecond regime. A novel in-vacuum spectrometer has been developed for spectroscopy of coherent radiation in the THz and infrared range. The spectrometer is equipped with five consecutive dispersion gratings and 120 parallel readout channels; it can be operated either in short wavelength mode (5-44 {mu}m) or in long wavelength mode (45-430 {mu}m). Fast parallel readout permits the spectroscopy of coherent radiation from single electron bunches. Test measurements at the soft X-ray free-electron laser FLASH, using coherent transition radiation, demonstrate excellent performance of the spectrometer. The high sensitivity down to a few micrometers allows study of short bunch features caused for example by microbunching e ects in magnetic chicanes. The device is planned for use as an online bunch profile monitor during regular FEL operation. (orig.)

  14. What do satellite backscatter ultraviolet and visible spectrometers see over snow and ice? A study of clouds and ozone using the A-train

    Directory of Open Access Journals (Sweden)

    A. P. Vasilkov

    2010-01-01

    Full Text Available In this paper, we examine how clouds over snow and ice affect ozone absorption and how these effects may be accounted for in satellite retrieval algorithms. Over snow and ice, the Aura Ozone Monitoring Instrument (OMI Raman cloud pressure algorithm derives an effective scene pressure. When this scene pressure differs appreciably from the surface pressure, the difference is assumed to be caused by a cloud that is shielding atmospheric absorption and scattering below cloud-top from satellite view. A pressure difference of 100 hPa is used as a crude threshold for the detection of clouds that significantly shield tropospheric ozone absorption. Combining the OMI effective scene pressure and the Aqua MODerate-resolution Imaging Spectroradiometer (MODIS cloud top pressure, we can distinguish between shielding and non-shielding clouds.

    To evaluate this approach, we performed radiative transfer simulations under various observing conditions. Using cloud vertical extinction profiles from the CloudSat Cloud Profiling Radar (CPR, we find that clouds over a bright surface can produce significant shielding (i.e., a reduction in the sensitivity of the top-of-the-atmosphere radiance to ozone absorption below the clouds. The amount of shielding provided by clouds depends upon the geometry (solar and satellite zenith angles and the surface albedo as well as cloud optical thickness. We also use CloudSat observations to qualitatively evaluate our approach. The CloudSat, Aqua, and Aura satellites fly in an afternoon polar orbit constellation with ground overpass times within 15 min of each other.

    The current Total Ozone Mapping Spectrometer (TOMS total column ozone algorithm (that has also been applied to the OMI assumes no clouds over snow and ice. This assumption leads to errors in the retrieved ozone column. We show that the use of OMI effective scene pressures over snow and ice reduces these errors and leads to a more homogeneous spatial

  15. Advanced 360o FOV, wide energy range, non-HV, gated time of flight mass spectrometers for Small Satellites and Cubesats

    Science.gov (United States)

    Paschalidis, N.; Jones, S.; Rodriguez, M.; Sittler, E. C., Jr.; Chornay, D. J.; Uribe, P.; Cameron, T.; Nanan, G.

    2015-12-01

    The time of flight technique is widely used for composition analysis of space plasma instruments. The foil - MCP/CEM combination is commonly used for E x TOF mass analysis at the cost of energy threshold, scattering, and direct particle interaction which ultimately affect performance. An alternative method especially effective at low energies is gated time of flight where the start foil is replaced with electric gating. There are several advantages of electric gating, including elimination of heavy HVPS required for pre-reacceleration to overcome foil thresholds, non- destructive interaction with atomic and molecular ions before analysis, and electronic controllability including geometric factor adjustment for flux dynamic range, FOV optimization, electronic filtering of most abundant elements in favor of minor species, and other properties affecting directly the scientific and engineering performance of the instruments. In addition special secondary emission surfaces can be used for triple coincidence when needed. The combination of electric gating and special surfaces works in an extensive energy range from 0 to tens of KeV without the need of start foil/HVPS making thus the use attractive to small satellites and cubesats. Those characteristics will be elaborated in the context of a gated time of flight wide field of view and energy range ion spectrometer combined with a neutral mass spectrometer (WINMS) developed at GSFC. The instrument prototypes have mass resolution adequate to separate N, O, OH, OH2; also static from ram moving H allowing thus separation of outgassing from ambient gases. A first implementation INMS with a mass <600 grams and size <1.5U is the main payload of the EXOCUBE Cubesat mission launched in January 2015 and already produced flight data; a second upgraded implementation is on onboard the GSFC Dellingr 6U CubeSat scheduled for launch in late 2015; and ongoing developments are baselined for other satellite missions.

  16. Maximizing the Use of Satellite Thermal Infrared Data for Advancing Land Surface Temperature Analysis

    Science.gov (United States)

    Weng, Q.; Fu, P.; Gao, F.

    2014-12-01

    Land surface temperature (LST) is a crucial parameter in investigating environmental, ecological processes and climate change at various scales, and is also valuable in the studies of evapotranspiration, soil moisture conditions, surface energy balance, and urban heat islands. These studies require thermal infrared (TIR) images at both high temporal and spatial resolution to retrieve LST. However, currently, no single satellite sensors can deliver TIR data at both high temporal and spatial resolution. Thus, various algorithms/models have been developed to enhance the spatial or the temporal resolution of TIR data, but rare of those can enhance both spatial and temporal details. This paper presents a new data fusion algorithm for producing Landsat-like LST data by blending daily MODIS and periodic Landsat TM datasets. The original Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) was improved and modified for predicting thermal radiance and LST data by considering annual temperature cycle (ATC) and urban thermal landscape heterogeneity. The technique of linear spectral mixture analysis was employed to relate the Landsat radiance with the MODIS one, so that the temporal changes in radiance can be incorporated in the fusion model. This paper details the theoretical basis and the implementation procedures of the proposed data fusion algorithm, Spatio-temporal Adaptive Data Fusion Algorithm for Temperature mapping (SADFAT). A case study was conducted that predicted LSTs of five dates in 2005 from July to October in Los Angeles County, California. The results indicate that the prediction accuracy for the whole study area ranged from 1.3 K to 2 K. Like existing spatio-temporal data fusion models, the SADFAT method has a limitation in predicting LST changes that were not recorded in the MODIS and/or Landsat pixels due to the model assumption.

  17. Comparison of long term series of total ozone and NO2 column measurements in the southern tropics by SAOZ/NDACC UV-Vis spectrometers and satellites

    Directory of Open Access Journals (Sweden)

    M. Pastel

    2013-05-01

    Full Text Available Long series of ozone and NO2 total column measurements at the Southern tropics are available from two ground-based SAOZ (Système d'Analyse par Observation Zenithale UV-visible spectrometers operated within the NDACC (Network for the Detection of Amtospheric Composition Change deployed in Bauru in S-E Brazil and Reunion Island in the S-W Indian Ocean in 1995 and 1993 respectively. Although at the same latitude, the data show larger columns of both species above the South American continent than above the Indian Ocean. For verifying the reliability of these data before carrying out trend analysis, they have been compared to satellites observations available during the same period. However, since no single satellite was operating from 1995 until present, the comparison requires the building of a composite, called merged satellites series. As systematic differences exist between the individual data sets because of the many differences between instruments, spectral ranges, absorption cross-sections, and retrieval procedures used, the building of such a composite requires thorough evaluation and normalisation of each. From comparisons with SAOZ, the merged satellite data set build with EP-TOMS from 1995 to 2004 and OMI-TOMS from 2005 to 2012 are found best for ozone in the Southern tropics. After correction for biases with SAOZ, both are confirming the larger ozone columns reported by SAOZ above South America compared to the Indian Ocean shown to origin from ozone production by lightning NOx (LNOx over the continent in the summer and the advection from Africa of ozone produced by biomass burning emissions in the winter. For NO2, best matching the SAOZ is a combination of GOME GDP4 1996–2003 and SCIAMACHY 2003–2012 products, after correction for the photochemical diurnal change of the concentration of the species between the SAOZ twilight observations and the time of satellites overpasses. The merged data series built from the data of these two

  18. All sky imaging observations in visible and infrared waveband for validation of satellite cloud and aerosol products

    Science.gov (United States)

    Lu, Daren; Huo, Juan; Zhang, W.; Liu, J.

    A series of satellite sensors in visible and infrared wavelengths have been successfully operated on board a number of research satellites, e.g. NOAA/AVHRR, the MODIS onboard Terra and Aqua, etc. A number of cloud and aerosol products are produced and released in recent years. However, the validation of the product quality and accuracy are still a challenge to the atmospheric remote sensing community. In this paper, we suggest a ground based validation scheme for satellite-derived cloud and aerosol products by using combined visible and thermal infrared all sky imaging observations as well as surface meteorological observations. In the scheme, a visible digital camera with a fish-eye lens is used to continuously monitor the all sky with the view angle greater than 180 deg. The digital camera system is calibrated for both its geometry and radiance (broad blue, green, and red band) so as to a retrieval method can be used to detect the clear and cloudy sky spatial distribution and their temporal variations. A calibrated scanning thermal infrared thermometer is used to monitor the all sky brightness temperature distribution. An algorithm is developed to detect the clear and cloudy sky as well as cloud base height by using sky brightness distribution and surface temperature and humidity as input. Based on these composite retrieval of clear and cloudy sky distribution, it can be used to validate the satellite retrievals in the sense of real-simultaneous comparison and statistics, respectively. What will be presented in this talk include the results of the field observations and comparisons completed in Beijing (40 deg N, 116.5 deg E) in year 2003 and 2004. This work is supported by NSFC grant No. 4002700, and MOST grant No 2001CCA02200

  19. Detection of supercooled liquid water-topped mixed-phase clouds >from shortwave-infrared satellite observations

    Science.gov (United States)

    NOH, Y. J.; Miller, S. D.; Heidinger, A. K.

    2015-12-01

    Many studies have demonstrated the utility of multispectral information from satellite passive radiometers for detecting and retrieving the properties of cloud globally, which conventionally utilizes shortwave- and thermal-infrared bands. However, the satellite-derived cloud information comes mainly from cloud top or represents a vertically integrated property. This can produce a large bias in determining cloud phase characteristics, in particular for mixed-phase clouds which are often observed to have supercooled liquid water at cloud top but a predominantly ice phase residing below. The current satellite retrieval algorithms may report these clouds simply as supercooled liquid without any further information regarding the presence of a sub-cloud-top ice phase. More accurate characterization of these clouds is very important for climate models and aviation applications. In this study, we present a physical basis and preliminary results for the algorithm development of supercooled liquid-topped mixed-phase cloud detection using satellite radiometer observations. The detection algorithm is based on differential absorption properties between liquid and ice particles in the shortwave-infrared bands. Solar reflectance data in narrow bands at 1.6 μm and 2.25 μm are used to optically probe below clouds for distinction between supercooled liquid-topped clouds with and without an underlying mixed phase component. Varying solar/sensor geometry and cloud optical properties are also considered. The spectral band combination utilized for the algorithm is currently available on Suomi NPP Visible/Infrared Imaging Radiometer Suite (VIIRS), Himawari-8 Advanced Himawari Imager (AHI), and the future GOES-R Advance Baseline Imager (ABI). When tested on simulated cloud fields from WRF model and synthetic ABI data, favorable results were shown with reasonable threat scores (0.6-0.8) and false alarm rates (0.1-0.2). An ARM/NSA case study applied to VIIRS data also indicated promising

  20. Atmospheric influences on infrared-laser signals used for occultation measurements between Low Earth Orbit satellites

    Directory of Open Access Journals (Sweden)

    S. Schweitzer

    2011-05-01

    Full Text Available LEO-LEO infrared-laser occultation (LIO is a new occultation technique between Low Earth Orbit (LEO satellites, which applies signals in the short wave infrared spectral range (SWIR within 2 μm to 2.5 μm. It is part of the LEO-LEO microwave and infrared-laser occultation (LMIO method, recently introduced by Kirchengast and Schweitzer (2011, that enables to retrieve thermodynamic profiles (pressure, temperature, humidity and accurate altitude levels from microwave signals and profiles of greenhouse gases and further variables such as line-of-sight wind speed from simultaneously measured LIO signals. For enabling trace species retrieval based on differential transmission, the LIO signals are spectrally located as pairs, one in the centre of a suitable absorption line of a target species (absorption signal and one close by but outside of any absorption lines (reference signal. Due to the novelty of the LMIO method, detailed knowledge of atmospheric influences on LIO signals and of their suitability for accurate trace species retrieval did not yet exist. Here we discuss the atmospheric influences on the transmission and differential transmission of LIO signals. Refraction effects, trace species absorption (by target species, and cross-sensitivity to foreign species, aerosol extinction and Rayleigh scattering are studied in detail. The influences of clouds, turbulence, wind, scattered solar radiation and terrestrial thermal radiation are discussed as well. We show that the influence of defocusing, foreign species absorption, aerosols and turbulence is observable, but can be rendered small to negligible by use of the differential transmission principle and by a design with close frequency spacing of absorption and reference signals within 0.5 %. The influences of Rayleigh scattering and thermal radiation on the received signal intensities are found negligible. Cloud-scattered solar radiation can be observable under bright-day conditions but this

  1. Non-linearity issues and multiple ionization satellites in the PIXE portion of spectra from the Mars alpha particle X-ray spectrometer

    Science.gov (United States)

    Campbell, John L.; Heirwegh, Christopher M.; Ganly, Brianna

    2016-09-01

    Spectra from the laboratory and flight versions of the Curiosity rover's alpha particle X-ray spectrometer were fitted with an in-house version of GUPIX, revealing departures from linear behavior of the energy-channel relationships in the low X-ray energy region where alpha particle PIXE is the dominant excitation mechanism. The apparent energy shifts for the lightest elements present were attributed in part to multiple ionization satellites and in part to issues within the detector and/or the pulse processing chain. No specific issue was identified, but the second of these options was considered to be the more probable. Approximate corrections were derived and then applied within the GUAPX code which is designed specifically for quantitative evaluation of APXS spectra. The quality of fit was significantly improved. The peak areas of the light elements Na, Mg, Al and Si were changed by only a few percent in most spectra. The changes for elements with higher atomic number were generally smaller, with a few exceptions. Overall, the percentage peak area changes are much smaller than the overall uncertainties in derived concentrations, which are largely attributable to the effects of rock heterogeneity. The magnitude of the satellite contributions suggests the need to incorporate these routinely in accelerator-based PIXE using helium beams.

  2. Accuracy Assessments and Validation of an Expanded UV Irradiance Database from Satellite Total Ozone Mapping Spectrometer (TOMS)

    Science.gov (United States)

    Krotkov, N. A.; Herman, J.; Fioletov, V.; Seftor, C.; Larko, D.; Vasilkov, A.

    2004-01-01

    The TOMS UV irradiance database (1978 to 2000) has been expanded to include 5 new products (noon irradiance at 305, 310, 324, and 380 nm, and noon erythemal-weighted irradiance), in addition to the existing erythemal daily exposure, which permit direct Comparisons with ground-based measurements from UV spectrometers. Sensitivity studies are conducted to estimate uncertainties of the new TOMS UV irradiance data due to algorithm apriori assumptions. Comparisons with Brewer spectrometers as well as filter radiometers are used to review of the sources of known errors. Inability to distinguish between snow and cloud cover using only TOMS data results in large errors in estimating surface UV using snow climatology. A correction is suggested for the case when the regional snow albedo is known from an independent source. The summer-time positive bias between TOMS UV estimations and Brewer measurements can be seen at all wavelengths. This suggests the difference is not related to ozone absorption effects. We emphasize that uncertainty of boundary layer UV aerosol absorption properties remains a major source of error in modeling UV irradiance in clear sky conditions. Neglecting aerosol absorption by the present TOMS algorithm results in a positive summertime bias in clear-sky UV estimations over many locations. Due to high aerosol variability the bias is strongly site dependent. Data from UV-shadow-band radiometer and well-calibrated CIMEL sun-sky radiometer are used to quantify the bias at NASA/GSFC site in Greenbelt, MD. Recommendations are given to enable potential users to better account for local conditions by combining standard TOMS UV data with ancillary ground measurements.

  3. Design of a satellite end-to-end mission performance simulator for imaging spectrometers and its application to the ESA's FLEX/Sentinel-3 tandem mission

    Science.gov (United States)

    Vicent, Jorge; Sabater, Neus; Tenjo, Carolina; Acarreta, Juan R.; Manzano, María.; Rivera, Juan P.; Jurado, Pedro; Franco, Raffaella; Alonso, Luis; Moreno, Jose

    2015-09-01

    The performance analysis of a satellite mission requires specific tools that can simulate the behavior of the platform; its payload; and the acquisition of scientific data from synthetic scenes. These software tools, called End-to-End Mission Performance Simulators (E2ES), are promoted by the European Space Agency (ESA) with the goal of consolidating the instrument and mission requirements as well as optimizing the implemented data processing algorithms. Nevertheless, most developed E2ES are designed for a specific satellite mission and can hardly be adapted to other satellite missions. In the frame of ESA's FLEX mission activities, an E2ES is being developed based on a generic architecture for passive optical missions. FLEX E2ES implements a state-of-the-art synthetic scene generator that is coupled with dedicated algorithms that model the platform and instrument characteristics. This work will describe the flexibility of the FLEX E2ES to simulate complex synthetic scenes with a variety of land cover classes, topography and cloud cover that are observed separately by each instrument (FLORIS, OLCI and SLSTR). The implemented algorithms allows modelling the sensor behavior, i.e. the spectral/spatial resampling of the input scene; the geometry of acquisition; the sensor noises and non-uniformity effects (e.g. stray-light, spectral smile and radiometric noise); and the full retrieval scheme up to Level-2 products. It is expected that the design methodology implemented in FLEX E2ES can be used as baseline for other imaging spectrometer missions and will be further expanded towards a generic E2ES software tool.

  4. Satellite Thermal Infrared Earthquake Precursor to the Wenchuan Ms 8.0 Earthquake in Sichuan, China, and its Analysis on Geo-dynamics

    Institute of Scientific and Technical Information of China (English)

    WEI Lejun; GUO Jianfeng; LIU Jianhua; LU Zhenquan; LI Haibing; CAI Hui

    2009-01-01

    Based on an interpretation and study of the satellite remote-sensing images of FY-2C thermal infrared 1st wave band (10.3-11.3 μm) designed in China, the authors found that there existed obvious and isolated satellite thermal infrared anomalies before the 5.12 Wenchuan Ms 8.0 Earthquake. These anomalies had the following characteristics: (1) The precursor appeared rather early: on March 18, 2008, I.e., 55 days before the earthquake, thermal infrared anomalies began to occur; (2) The anomalies experienced quite many and complex evolutionary stages: the satellite thermal infrared anomalies might be divided into five stages, whose manifestations were somewhat different from each other. The existence of so many anomaly stages was probably observed for the first time in numerous cases of satellite thermal infrared research on earthquakes; (3) Each stage lasted quite a long time, with the longest one spanning 13 days; (4) An evident geothermal anomaly gradient was distributed along the Longmen seismic fracture zone, and such a phenomenon might also be discovered for the first time in satellite thermal infrared earthquake research. This discovery is therefore of great guiding and instructive significance in the study of the earthquake occurrence itself and the trend of the post-earthquake phenomena.

  5. The Cosmic Background Explorer Satellite

    Science.gov (United States)

    Mather, J.; Kelsall, T.

    1980-01-01

    The Cosmic Background Explorer (COBE) satellite, planned for launch in 1985, will measure the diffuse infrared and microwave radiation of the universe over the entire wavelength range from a few microns to 1.3 cm. It will include three instruments: a set of microwave isotropy radiometers at 23, 31, 53, and 90 GHz, an interferometer spectrometer from 1 to 100/cm, and a filter photometer from 1 to 300 microns. The COBE satellite is designed to reach the sensitivity limits set by foreground sources such as the interstellar and interplanetary dust, starlight, and galactic synchrotron radiation, so that a diffuse residual radiation may be interpreted unambiguously as extragalactic

  6. Assessment of Transition Element Speciation in Glasses Using a Portable Transmission Ultraviolet-Visible-Near-Infrared (UV-Vis-NIR) Spectrometer.

    Science.gov (United States)

    Hunault, Myrtille; Lelong, Gérald; Gauthier, Michel; Gélébart, Frédéric; Ismael, Saindou; Galoisy, Laurence; Bauchau, Fanny; Loisel, Claudine; Calas, Georges

    2016-05-01

    A new low-cost experimental setup based on two compact dispersive optical spectrometers has been developed to measure optical absorption transmission spectra over the 350-2500 nm energy range. We demonstrate how near-infrared (NIR) data are essential to identify the coloring species in addition to ultraviolet visible data. After calibration with reference glasses, the use of an original sample stage that maintains the window panel in the vertical position enables the comparison of ancient and modern glasses embedded in a panel from the Sainte-Chapelle of Paris, without any sampling. The spectral resolution enables to observe fine resonances arising in the absorption bands of Cr(3+), and the complementary information obtained in the NIR enables to determine the contribution of Fe(2+), a key indicator of glassmaking conditions. © The Author(s) 2016.

  7. Advancing satellite-based solar power forecasting through integration of infrared channels for automatic detection of coastal marine inversion layer

    Energy Technology Data Exchange (ETDEWEB)

    Kostylev, Vladimir; Kostylev, Andrey; Carter, Chris; Mahoney, Chad; Pavlovski, Alexandre; Daye, Tony [Green Power Labs Inc., Dartmouth, NS (Canada); Cormier, Dallas Eugene; Fotland, Lena [San Diego Gas and Electric Co., San Diego, CA (United States)

    2012-07-01

    The marine atmospheric boundary layer is a layer or cool, moist maritime air with the thickness of a few thousand feet immediately below a temperature inversion. In coastal areas as moist air rises from the ocean surface, it becomes trapped and is often compressed into fog above which a layer of stratus clouds often forms. This phenomenon is common for satellite-based solar radiation monitoring and forecasting. Hour ahead satellite-based solar radiation forecasts are commonly using visible spectrum satellite images, from which it is difficult to automatically differentiate low stratus clouds and fog from high altitude clouds. This provides a challenge for cloud motion tyracking and cloud cover forecasting. San Diego Gas and Electric {sup registered} (SDG and E {sup registered}) Marine Layer Project was undertaken to obtain information for integration with PV forecasts, and to develop a detailed understanding of long-term benefits from forecasting Marine Layer (ML) events and their effects on PV production. In order to establish climatological ML patterns, spatial extent and distribution of marine layer, we analyzed visible and IR spectrum satellite images (GOES WEST) archive for the period of eleven years (2000 - 2010). Historical boundaries of marine layers impact were established based on the cross-classification of visible spectrum (VIS) and infrared (IR) images. This approach is successfully used by us and elsewhere for evaluating cloud albedo in common satellite-based techniques for solar radiation monitoring and forecasting. The approach allows differentiation of cloud cover and helps distinguish low laying fog which is the main consequence of marine layer formation. ML occurrence probability and maximum extent inland was established for each hour and day of the analyzed period and seasonal/patterns were described. SDG and E service area is the most affected region by ML events with highest extent and probability of ML occurrence. Influence of ML was the

  8. Angular acceptance analysis of an infrared focal plane array with a built-in stationary Fourier transform spectrometer.

    Science.gov (United States)

    Gillard, Frédéric; Ferrec, Yann; Guérineau, Nicolas; Rommeluère, Sylvain; Taboury, Jean; Chavel, Pierre

    2012-06-01

    Stationary Fourier transform spectrometry is an interesting concept for building reliable field or embedded spectroradiometers, especially for the mid- and far- IR. Here, a very compact configuration of a cryogenic stationary Fourier transform IR (FTIR) spectrometer is investigated, where the interferometer is directly integrated in the focal plane array (FPA). We present a theoretical analysis to explain and describe the fringe formation inside the FTIR-FPA structure when illuminated by an extended source positioned at a finite distance from the detection plane. The results are then exploited to propose a simple front lens design compatible with a handheld package.

  9. Rapid and non-destructive determination of quality parameters in the 'Tommy Atkins' mango using a novel handheld near infrared spectrometer.

    Science.gov (United States)

    Marques, Emanuel José Nascimento; de Freitas, Sérgio Tonetto; Pimentel, Maria Fernanda; Pasquini, Celio

    2016-04-15

    The objective of this study was to evaluate the potential of a new handheld ultra-compact near infrared (NIR) spectrometer, based on the linear-variable filter (LVF) technology for rapid and non-destructive quality control analysis of the 'Tommy Atkins' mango. Multivariate calibration models were built using the Partial Least Squares (PLS) regression method to determine soluble solids (SS), dry matter (DM), titratable acidity (TA) and pulp firmness (PF). Different spectral pre-processing techniques were tested. Coefficient of determination and root mean square errors of prediction (RMSEP) values were, respectively: 0.92 and 0.55°Brix for SS, 0.67 and 0.51% for DM, 0.50 and 0.17% citric acid for TA, 0.72 and 12.2N for PF. The predictive models allowed monitoring physico-chemical changes in each fruit during ripening. The results show the feasibility of using the new NIR handheld spectrometer to determine quality parameters in the 'Tommy Atkins' mango. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Performance of a long-wave infrared Fourier Transform imaging spectrometer using a corner-cube Michelson interferometer and an uncooled microbolometer array

    Science.gov (United States)

    Wang, Nan; Wu, Jianghui; Meng, Hemin; Gao, Jiaobo; Fan, Zhe; Zhang, Mingxuan; Li, Yu; Li, Jianjun

    2015-10-01

    Interference imaging spectroscopy is the advanced subject among the infrared remote sensing, and it has become an important technique to detect spatial information and spectral information of targets. It has the advantages of high flux, high spectral resolution and high spatial resolution that can be used for detecting more details of the spectral and spatial information. Based on a Michelson interferometer with its mirrors replaced by corner-cubes, principles of a hand-held, static, long-wave infrared Fourier Transform(FT) imaging spectrometer using an uncooled microbolometer array are introduced. Because in such FT-based spectral imager, the interferogram is acquired over the whole field of the camera while the scene of interest scans the path difference range, vignetting should be strongly limited while keep the size of the interferometer as small as possible. Interferometer size is given and interferential light path is verified through TracePro software. First results of field and laboratory measurements using the spectral imager are presented. Remotely obtained spectrums collected with this instrument and with those of high precise Michelson spectrometer are compared, and the measured values turned out to be closely corresponded. The results, in turn, verified the feasibility of the systematic working mode. The resulting system tested here provides datacubes of up to 640×480 pixels over the 7.7~13μm spectral range, this wavelength range reveals important information about scenes such as gas or landmine detection, and the instrument has a spectral resolution of about 8cm-1 that fulfils the requirement for most targeted applications. Examples of sky and buildings detection are shown.

  11. An evaluation method of reflectance spectra to be obtained by Hayabusa2 Near-Infrared Spectrometer (NIRS3) based on laboratory measurements of carbonaceous chondrites

    Science.gov (United States)

    Matsuoka, Moe; Nakamura, Tomoki; Osawa, Takahito; Iwata, Takahiro; Kitazato, Kohei; Abe, Masanao; Nakauchi, Yusuke; Arai, Takehiko; Komatsu, Mutsumi; Hiroi, Takahiro; Imae, Naoya; Yamaguchi, Akira; Kojima, Hideyasu

    2017-09-01

    We conducted ground-based performance evaluation tests of the Near-Infrared Spectrometer (NIRS3) onboard Hayabusa2 spacecraft in November 2013 and from April to May 2014 and established a method for evaluating its measured reflectance spectra. Reflectance spectra of nine powdered carbonaceous chondrite samples were measured by both NIRS3 and a Fourier transform infrared (FT-IR) spectrometer. We have established two methods for correcting the NIRS3 data by comparing them with the corresponding FT-IR data because raw data obtained by NIRS3 underwent spectral distortion caused by systematic offsets in sensitivity of individual pixels. The corrected NIRS3 spectra of carbonaceous chondrite samples are comparable with their FT-IR spectra. The depth of each band component D λ is defined for each wavelength λ (μm) to characterize the absorption bands in NIRS3 spectra. It is suggested that the relationship between the D 2.72/ D 2.79 ratio and the D 2.76/ D 2.90 ratio would be useful for estimating the degree of heating of the asteroid surface, if contributions of terrestrial adsorbed water on D 2.79 and D 2.90 are properly corrected. The degrees of heating and space weathering are also comprehensively evaluated by the relationship between D 2.90 and the D 2.76/ D 2.90 ratio. Reflectance spectra of asteroid Ryugu, the target asteroid of Hayabusa2, to be recorded by the NIRS3 instrument are expected to reveal the characteristics of the surface materials by using the evaluation technique proposed in this paper. Such information will be used for choosing the touchdown points for sampling and also for investigating the distribution of the materials similar to the returned samples on Ryugu.[Figure not available: see fulltext.

  12. Improving Atmospheric Correction for Visible/Short Wave Infrared (VSWIR) Imaging Spectrometers with Iterative Fitting of Absorption By Three Phases of Water

    Science.gov (United States)

    Pennington, E. A.; Thompson, D. R.; Green, R. O.; Gao, B. C.

    2014-12-01

    Airborne imaging spectrometers like the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) offer valuable insight into the Earth's terrestrial and ocean ecosystems, mineralogy, and land use. Estimating surface reflectance requires accounting for atmospheric absorption, which is sensitive to the local abundance of water vapor. Analysts typically estimate water vapor concentrations using the depths of absorption features, which can be inaccurate by up to 50% over surface features containing liquid water or ice. This can bias the retrieved water vapor maps and create atmospheric artifacts in reflectance spectra. A new retrieval method offers significant accuracy improvements over plant canopies or ice by estimating the path lengths of all three phases of water simultaneously, adjusting absorptions to best fit the measurement over a broader spectral interval. This paper assesses the remaining sources of error for the three-phase retrieval technique. We analyze retrievals for synthetic data when the 940 and 1140 nm wavelength features are fitted, for initial vapor path estimates ranging from 0 to ±50% accuracy. These tests indicate that most error comes from inaccuracy in the initial path estimate used to obtain vapor absorption coefficients. We evaluate a modified algorithm that uses multiple iterations to refine this estimate. Error is found to approach a constant value, demonstrating improved robustness to initialization conditions. We also assess the new iterative method using corrected AVIRIS data over various environments. The iterative method yields significantly better water vapor maps, reducing spurious correlations between vegetation canopy water and vapor estimates. The new iterative method offers accuracy improvements over traditional Visible/Short Wave Infrared (VSWIR) atmospheric correction methods, at modest computational cost.

  13. Assimilation of microwave, infrared, and radio occultation satellite observations with a weather research and forecasting model for heavy rainfall forecasting

    Science.gov (United States)

    Boonyuen, Pakornpop; Wu, Falin; Phunthirawuth, Parwapath; Zhao, Yan

    2016-10-01

    In this research, satellite observation data were assimilated into Weather Research and Forecasting Model (WRF) by using Three-dimensional Variational Data Assimilation System (3DVAR) to analyze its impacts on heavy rainfall forecasts. The weather case for this research was during 13-18 September 2015. Tropical cyclone VAMCO, forming in South China Sea near with Vietnam, moved on west direction to the Northeast of Thailand. After passed through Vietnam, the tropical cyclone was become to depression and there was heavy rainfall throughout the area of Thailand. Observation data, used in this research, included microwave radiance observations from the Advanced Microwave Sounding Unit-A (AMSU-A), infrared radiance observations from Infrared Atmospheric Sounding Interferometer (IASI), and GPS radio occultation (RO) from the COSMIC and CHAMP missions. The experiments were designed in five cases, namely, 1) without data assimilation (CTRL); 2) with only RO data (RO); 3) with only AMSU-A data (AMSUA); 4) with only IASI data (IASI); and 5) with all of RO, AMSU-A and IASI data assimilation (ALL). Then all experiment results would be compared with both NCEP FNL (Final) Operational Global Analysis and the observation data from Thai Meteorological Department weather stations. The experiments result demonstrated that with microwave (AMSU-A), infrared (IASI) and GPS radio occultation (RO) data assimilation can produce the positive impact on analyses and forecast. All of satellite data assimilations have corresponding positive effects in term of temperature and humidity forecasting, and the GPS-RO assimilation produces the best of temperature and humidity forecast biases. The satellite data assimilation has a good impact on temperature and humidity in lower troposphere and vertical distribution that very helpful for heavy rainfall forecast improvement.

  14. Characterizing Exoplanets in the Visible and Infrared: A Spectrometer Concept for the EChO Space Mission

    CERN Document Server

    Glauser, A M; Krause, O; Henning, Th; Benneke, B; Bouwman, J; Cubillos, P E; Crossfield, I J M; Detre, Ö H; Ebert, M; Grözinger, U; Güdel, M; Harrington, J; Justtanont, K; Klaas, U; Lenzen, R; Madhusudhan, N; Meyer, M R; Mordasini, C; Müller, F; Ottensamer, R; Plesseria, J -Y; Quanz, S P; Reiners, A; Renotte, E; Rohloff, R -R; Scheithauer, S; Schmid, H M; Schrader, J -R; Seemann, U; Stam, D; Vandenbussche, B; Wehmeier, U

    2013-01-01

    Transit-spectroscopy of exoplanets is one of the key observational techniques to characterize the extrasolar planet and its atmosphere. The observational challenges of these measurements require dedicated instrumentation and only the space environment allows an undisturbed access to earth-like atmospheric features such as water or carbon-dioxide. Therefore, several exoplanet-specific space missions are currently being studied. One of them is EChO, the Exoplanet Characterization Observatory, which is part of ESA's Cosmic Vision 2015-2025 program, and which is one of four candidates for the M3 launch slot in 2024. In this paper we present the results of our assessment study of the EChO spectrometer, the only science instrument onboard this spacecraft. The instrument is a multi-channel all-reflective dispersive spectrometer, covering the wavelength range from 400 nm to 16 microns simultaneously with a moderately low spectral resolution. We illustrate how the key technical challenge of the EChO mission - the high...

  15. Wavelength calibration of dispersive near-infrared spectrometer using relative k-space distribution with low coherence interferometer

    Science.gov (United States)

    Kim, Ji-hyun; Han, Jae-Ho; Jeong, Jichai

    2016-05-01

    The commonly employed calibration methods for laboratory-made spectrometers have several disadvantages, including poor calibration when the number of characteristic spectral peaks is low. Therefore, we present a wavelength calibration method using relative k-space distribution with low coherence interferometer. The proposed method utilizes an interferogram with a perfect sinusoidal pattern in k-space for calibration. Zero-crossing detection extracts the k-space distribution of a spectrometer from the interferogram in the wavelength domain, and a calibration lamp provides information about absolute wavenumbers. To assign wavenumbers, wavelength-to-k-space conversion is required for the characteristic spectrum of the calibration lamp with the extracted k-space distribution. Then, the wavelength calibration is completed by inverse conversion of the k-space into wavelength domain. The calibration performance of the proposed method was demonstrated with two experimental conditions of four and eight characteristic spectral peaks. The proposed method elicited reliable calibration results in both cases, whereas the conventional method of third-order polynomial curve fitting failed to determine wavelengths in the case of four characteristic peaks. Moreover, for optical coherence tomography imaging, the proposed method could improve axial resolution due to higher suppression of sidelobes in point spread function than the conventional method. We believe that our findings can improve not only wavelength calibration accuracy but also resolution for optical coherence tomography.

  16. A satellite-borne ion mass spectrometer for the energy range 0 to 16 keV

    Science.gov (United States)

    Balsiger, H.; Eberhardt, P.; Geiss, J.; Ghielmetti, A.; Walker, H. P.; Young, D. T.; Loidl, H.; Rosenbauer, H.

    1976-01-01

    The Ion Composition Experiment (ICE) on GEOS represents the first comprehensive attempt to measure the positive ion composition at high altitudes in the magnetosphere. Due to the heterogeneous nature of the magnetospheric plasma a novel mass spectrometer has been developed to cover the mass per charge range from H-1(+) to beyond Ba-138(+) and the energy per charge range from 0 to 16 keV/e. The ICE consists primarily of a cylindrical electrostatic analyzer followed by a curved analyzer incorporating crossed magnetic and electric fields. This combination has limited angular and energy focusing properties, but it maintains a mass resolution of about 4 over a wide range in energy and mass, sufficient for the objectives of measuring plasmas of both solar and terrestrial origin. High sensitivity and low background should allow measurements of rarer ion constituents down to flux levels of 0.01 ions/sq cm sec ster eV. A sophisticated electronics combined with powerful ground computer and telecommand systems allow for very efficient scanning of the mass-energy space.

  17. Design of a nano-satellite demonstrator of an infrared imaging space interferometer: the HyperCube

    Science.gov (United States)

    Dohlen, Kjetil; Vives, Sébastien; Rakotonimbahy, Eddy; Sarkar, Tanmoy; Tasnim Ava, Tanzila; Baccichet, Nicola; Savini, Giorgio; Swinyard, Bruce

    2014-07-01

    The construction of a kilometer-baseline far infrared imaging interferometer is one of the big instrumental challenges for astronomical instrumentation in the coming decades. Recent proposals such as FIRI, SPIRIT, and PFI illustrate both science cases, from exo-planetary science to study of interstellar media and cosmology, and ideas for construction of such instruments, both in space and on the ground. An interesting option for an imaging multi-aperture interferometer with km baseline is the space-based hyper telescope (HT) where a giant, sparsely populated primary mirror is constituted of several free-flying satellites each carrying a mirror segment. All the segments point the same object and direct their part of the pupil towards a common focus where another satellite, containing recombiner optics and a detector unit, is located. In Labeyrie's [1] original HT concept, perfect phasing of all the segments was assumed, allowing snap-shot imaging within a reduced field of view and coronagraphic extinction of the star. However, for a general purpose observatory, image reconstruction using closure phase a posteriori image reconstruction is possible as long as the pupil is fully non-redundant. Such reconstruction allows for much reduced alignment tolerances, since optical path length control is only required to within several tens of wavelengths, rather than within a fraction of a wavelength. In this paper we present preliminary studies for such an instrument and plans for building a miniature version to be flown on a nano satellite. A design for recombiner optics is proposed, including a scheme for exit pupil re-organization, is proposed, indicating the focal plane satellite in the case of a km-baseline interferometer could be contained within a 1m3 unit. Different options for realization of a miniature version are presented, including instruments for solar observations in the visible and the thermal infrared and giant planet observations in the visible, and an

  18. Exploration on Experimental Reform and Management Mode of Fourier Transform Infrared Spectrometer Teaching%傅里叶红外光谱仪教学及管理模式探究

    Institute of Scientific and Technical Information of China (English)

    刘荣军; 罗志辉; 韦庆敏; 曾楚杰

    2015-01-01

    对傅里叶红外光谱仪在教学和管理中存在的问题进行了详细地分析,然后探讨了红外光谱仪的教学管理模式,包括实验教学方法、教学模式和管理模式。通过改革其教学方法和教学模式,使学生快速熟练地掌握了红外光谱仪的操作过程,提高了红外光谱仪实验教学效果;通过改革管理模式,减轻了仪器管理员工作强度,提高了仪器的使用率,并且降低了仪器的故障率。%This paper analyses the current existing problems of Fourier Transform Infrared Spectrometer in teaching and management, discusses the model and method of Fourier Transform Infrared Spectrometer teaching and managing. By reforming the teaching methods and teaching mode, we help students quickly master infrared spectrometer operating process, thus improving the effect of the infrared spectrometer experiment teaching. Through the reform of the management pattern, we reduce the instrument administrator working strength, improve the efficiency of the instrument, and reduce the failure rate of the instrument.

  19. A compact thermal infrared imaging radiometer with high spatial resolution and wide swath for a small satellite using a large format uncooled infrared focal plane array

    Science.gov (United States)

    Tatsumi, Kenji; Sakuma, Fumihiro; Kikuchi, Masakuni; Tanii, Jun; Kawanishi, Toneo; Ueno, Shinichi; Kuga, Hideki

    2014-10-01

    In this paper, we present a feasibility study for the potential of a high spatial resolution and wide swath thermal infrared (TIR) imaging radiometer for a small satellite using a large format uncooled infrared focal plane array (IR-FPA). The preliminary TIR imaging radiometer designs were performed. One is a panchromatic (mono-band) imaging radiometer (8-12μm) with a large format 2000 x 1000 pixels uncooled IR-FPA with a pixel pitch of 15 μm. The other is a multiband imaging radiometer (8.8μm, 10.8μm, 11.4μm). This radiometer is employed separate optics and detectors for each wave band. It is based on the use of a 640 x 480 pixels uncooled IR-FPA with a pixel pitch of 25 μm. The thermal time constant of an uncooled IR-FPA is approximately 10-16ms, and introduces a constraint to the satellite operation to achieve better signal-to-noise ratio, MTF and linearity performances. The study addressed both on-ground time-delayintegration binning and staring imaging solutions, although a staring imaging was preferred after trade-off. The staring imaging requires that the line of sight of the TIR imaging radiometer gazes at a target area during the acquisition time of the image, which can be obtained by rotating the satellite or a steering mirror around the pitch axis. The single band radiometer has been designed to yield a 30m ground sample distance over a 30km swath width from a satellite altitude of 500km. The radiometric performance, enhanced with staring imaging, is expected to yield a NETD less than 0.5K for a 300K ground scene. The multi-band radiometer has three spectral bands with spatial resolution of 50m and swath width of 24km. The radiometric performance is expected to yield a NETD less than 0.85K. We also showed some preliminary simulation results on volcano, desert/urban scenes, and wildfire.

  20. THE APPLICATION OF HOMEMADE FY-2 SATELLITE INFRARED DATA TO MM5

    Institute of Scientific and Technical Information of China (English)

    LIU Qing; SHEN Tong-li

    2006-01-01

    @@ 1 INTRODUCTION In the end of 1980's, an operational system for 3-D variation and assimilation of meteorological data was set up in the U.S.A that supplemented data assimilation,retrieval of satellite data and numerical prediction each other. NWP was thus improved. Towards the end of 1990's, satellite observations were extensively used in NWP at ECMWF to upgrade the quality of analysis and forecasting.

  1. X-ray spectrophotometer SphinX and particle spectrometer STEP-F of the satellite experiment CORONAS-PHOTON. Preliminary results of the joint data analysis

    Science.gov (United States)

    Dudnik, O. V.; Podgorski, P.; Sylwester, J.; Gburek, S.; Kowalinski, M.; Siarkowski, M.; Plocieniak, S.; Bakala, J.

    2012-04-01

    A joint analysis is carried out of data obtained with the help of the solar X-ray SphinX spectrophotometer and the electron and proton satellite telescope STEP-F in May 2009 in the course of the scientific space experiment CORONAS-PHOTON. In order to determine the energies and particle types, in the analysis of spectrophotometer records data are used on the intensities of electrons, protons, and secondary γ-radiation, obtained by the STEP-F telescope, which was located in close proximity to the SphinX spectrophotometer. The identical reaction of both instruments is noted at the intersection of regions of the Brazilian magnetic anomaly and the Earth's radiation belts. It is shown that large area photodiodes, serving as sensors of the X-ray spectrometer, reliably record electron fluxes of low and intermediate energies, as well as fluxes of the secondary gamma radiation from construction materials of detector modules, the TESIS instrument complex, and the spacecraft itself. The dynamics of electron fluxes, recorded by the SphinX spectrophotometer in the vicinity of a weak geomagnetic storm, supplements the information about the processes of radial diffusion of electrons, which was studied using the STEP-F telescope.

  2. From a single encapsulated detector to the spectrometer for INTEGRAL satellite: predicting the peak-to-total ratio at high gamma-energies

    CERN Document Server

    Kshetri, Ritesh

    2012-01-01

    In two recent papers (R. Kshetri, JINST 2012 7 P04008; ibid., P07006), a probabilistic formalism was introduced to predict the response of encapsulated type composite germanium detectors like the SPI (spectrometer for INTEGRAL satellite). Predictions for the peak-to-total and peak-to-background ratios are given at 1.3 MeV for the addback mode of operation. The application of the formalism to clover germanium detector is discussed in two separate papers (R. Kshetri, JINST 2012 7 P07008; ibid., P08015). Using the basic approach developed in those papers, for the first time we present a procedure for calculating the peak-to-total ratio of the cluster detector for gamma-energies up to 8 MeV. Results are shown for both bare and suppressed detectors as well as for the single crystal and addback modes of operation. We have considered the experimental data of (i) peak-to-total ratio at 1.3 MeV, and (ii) single detector efficiency and addback factor for other energies up to 8 MeV. Using this data, an approximate metho...

  3. Identification of dust outbreaks on infrared MSG-SEVIRI data by using a Robust Satellite Technique (RST)

    Science.gov (United States)

    Sannazzaro, Filomena; Filizzola, Carolina; Marchese, Francesco; Corrado, Rosita; Paciello, Rossana; Mazzeo, Giuseppe; Pergola, Nicola; Tramutoli, Valerio

    2014-01-01

    Dust storms are meteorological phenomena of great interest for scientific community because of their potential impact on climate changes, for the risk that may pose to human health and due to other issues as desertification processes and reduction of the agricultural production. Satellite remote sensing, thanks to global coverage, high frequency of observation and low cost data, may highly contribute in monitoring these phenomena, provided that proper detection methods are used. In this work, the known Robust Satellite Techniques (RST) multitemporal approach, used for studying and monitoring several natural/environmental hazards, is tested on some important dust events affecting Mediterranean region in May 2004 and Arabian Peninsula in February 2008. To perform this study, data provided by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) have been processed, comparing the generated dust maps to some independent satellite-based aerosol products. Outcomes of this work show that the RST technique can be profitably used for detecting dust outbreaks from space, providing information also about areas characterized by a different probability of dust presence. They encourage further improvements of this technique in view of its possible implementation in the framework of operational warning systems.

  4. Investigating the error budget of tropical rainfall accumulations derived from combined passive microwave and infrared satellite measurements

    Science.gov (United States)

    Roca, R.; Chambon, P.; jobard, I.; Viltard, N.

    2012-04-01

    Measuring rainfall requires a high density of observations, which, over the whole tropical elt, can only be provided from space. For several decades, the availability of satellite observations has greatly increased; thanks to newly implemented missions like the Megha-Tropiques mission and the forthcoming GPM constellation, measurements from space become available from a set of observing systems. In this work, we focus on rainfall error estimations at the 1 °/1-day accumulated scale, key scale of meteorological and hydrological studies. A novel methodology for quantitative precipitation estimation is introduced; its name is TAPEER (Tropical Amount of Precipitation with an Estimate of ERrors) and it aims to provide 1 °/1-day rain accumulations and associated errors over the whole Tropical belt. This approach is based on a combination of infrared imagery from a fleet of geostationary satellites and passive microwave derived rain rates from a constellation of low earth orbiting satellites. A three-stage disaggregation of error into sampling, algorithmic and calibration errors is performed; the magnitudes of the three terms are then estimated separately. A dedicated error model is used to evaluate sampling errors and a forward error propagation approach is used for an estimation of algorithmic and calibration errors. One of the main findings in this study is the large contribution of the sampling errors and the algorithmic errors of BRAIN on medium rain rates (2 mm h-1 to 10 mm h-1) in the total error budget.

  5. Fast In Situ Airborne Measurement of Ammonia Using a Mid-Infrared Off-Axis ICOS Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Leen, J. Brian; Yu, Xiao-Ying; Gupta, Manish; Baer, Douglas S.; Hubbe, John M.; Kluzek, Celine D.; Tomlinson, Jason M.; Hubbell, Mike R.

    2013-08-23

    A new ammonia (NH3) analyzer was developed based on off-axis integrated cavity output spectroscopy. Its feasibility was demonstrated by making tropospheric measurements in flights aboard the Department of Energy Gulfstream-1 aircraft. The ammonia analyzer consists of an optical cell, quantum-cascade laser, gas sampling system, control and data acquisition electronics, and analysis software. The NH3 mixing ratio is determined from high-resolution absorption spectra obtained by tuning the laser wavelength over the NH3 fundamental vibration band near 9.67 μm. Excellent linearity is obtained over a wide dynamic range (0–101 ppbv) with a response rate (1/e) of 2 Hz and a precision of ±90 pptv (1σ in 1 s). Two research flights were conducted over the Yakima Valley in Washington State. In the first flight, the ammonia analyzer was used to identify signatures of livestock from local dairy farms with high vertical and spatial resolution under low wind and calm atmospheric conditions. In the second flight, the analyzer captured livestock emission signals under windy conditions. Finally, our results demonstrate that this new ammonia spectrometer is capable of providing fast, precise, and accurate in situ observations of ammonia aboard airborne platforms to advance our understanding of atmospheric compositions and aerosol formation.

  6. Provisional maps of thermal areas in Yellowstone National Park, based on satellite thermal infrared imaging and field observations

    Science.gov (United States)

    Vaughan, R. Greg; Heasler, Henry; Jaworowski, Cheryl; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.

    2014-01-01

    Maps that define the current distribution of geothermally heated ground are useful toward setting a baseline for thermal activity to better detect and understand future anomalous hydrothermal and (or) volcanic activity. Monitoring changes in the dynamic thermal areas also supports decisions regarding the development of Yellowstone National Park infrastructure, preservation and protection of park resources, and ensuring visitor safety. Because of the challenges associated with field-based monitoring of a large, complex geothermal system that is spread out over a large and remote area, satellite-based thermal infrared images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were used to map the location and spatial extent of active thermal areas, to generate thermal anomaly maps, and to quantify the radiative component of the total geothermal heat flux. ASTER thermal infrared data acquired during winter nights were used to minimize the contribution of solar heating of the surface. The ASTER thermal infrared mapping results were compared to maps of thermal areas based on field investigations and high-resolution aerial photos. Field validation of the ASTER thermal mapping is an ongoing task. The purpose of this report is to make available ASTER-based maps of Yellowstone’s thermal areas. We include an appendix containing the names and characteristics of Yellowstone’s thermal areas, georeferenced TIFF files containing ASTER thermal imagery, and several spatial data sets in Esri shapefile format.

  7. Euclid Near Infrared Spectrometer and Photometer instrument concept and first test results obtained for different breadboards models at the end of phase C

    Science.gov (United States)

    Maciaszek, Thierry; Ealet, Anne; Jahnke, Knud; Prieto, Eric; Barbier, Rémi; Mellier, Yannick; Beaumont, Florent; Bon, William; Bonnefoi, Anne; Carle, Michael; Caillat, Amandine; Costille, Anne; Dormoy, Doriane; Ducret, Franck; Fabron, Christophe; Febvre, Aurélien; Foulon, Benjamin; Garcia, Jose; Gimenez, Jean-Luc; Grassi, Emmanuel; Laurent, Philippe; Le Mignant, David; Martin, Laurent; Rossin, Christelle; Pamplona, Tony; Sanchez, Patrice; Vives, Sébastien; Clémens, Jean Claude; Gillard, William; Niclas, Mathieu; Secroun, Aurélia; Serra, Benoit; Kubik, Bogna; Ferriol, Sylvain; Amiaux, Jérôme; Barrière, Jean Christophe; Berthe, Michel; Rosset, Cyrille; Macias-Perez, Juan Francisco; Auricchio, Natalia; De Rosa, Adriano; Franceschi, Enrico; Guizzo, Gian Paolo; Morgante, Gianluca; Sortino, Francesca; Trifoglio, Massimo; Valenziano, Luca; Patrizii, Laura; Chiarusi, T.; Fornari, F.; Giacomini, F.; Margiotta, A.; Mauri, N.; Pasqualini, L.; Sirri, G.; Spurio, M.; Tenti, M.; Travaglini, R.; Dusini, Stefano; Dal Corso, F.; Laudisio, F.; Sirignano, C.; Stanco, L.; Ventura, S.; Borsato, E.; Bonoli, Carlotta; Bortoletto, Favio; Balestra, Andrea; D'Alessandro, Maurizio; Medinaceli, Eduardo; Farinelli, Ruben; Corcione, Leonardo; Ligori, Sebastiano; Grupp, Frank; Wimmer, Carolin; Hormuth, Felix; Seidel, Gregor; Wachter, Stefanie; Padilla, Cristóbal; Lamensans, Mikel; Casas, Ricard; Lloro, Ivan; Toledo-Moreo, Rafael; Gomez, Jaime; Colodro-Conde, Carlos; Lizán, David; Diaz, Jose Javier; Lilje, Per B.; Toulouse-Aastrup, Corinne; Andersen, Michael I.; Sørensen, Anton N.; Jakobsen, Peter; Hornstrup, Allan; Jessen, Niels-Christian; Thizy, Cédric; Holmes, Warren; Israelsson, Ulf; Seiffert, Michael; Waczynski, Augustyn; Laureijs, René J.; Racca, Giuseppe; Salvignol, Jean-Christophe; Boenke, Tobias; Strada, Paolo

    2016-07-01

    The Euclid mission objective is to understand why the expansion of the Universe is accelerating through by mapping the geometry of the dark Universe by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision program with its launch planned for 2020 (ref [1]). The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (900- 2000nm) as a photometer and spectrometer. The instrument is composed of: - a cold (135K) optomechanical subsystem consisting of a Silicon carbide structure, an optical assembly (corrector and camera lens), a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control system - a detection subsystem based on a mosaic of 16 HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a mechanical focal plane structure made with molybdenum and aluminum. The detection subsystem is mounted on the optomechanical subsystem structure - a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the spacecraft via a 1553 bus for command and control and via Spacewire links for science data This presentation describes the architecture of the instrument at the end of the phase C (Detailed Design Review), the expected performance, the technological key challenges and preliminary test results obtained for different NISP subsystem breadboards and for the NISP Structural and Thermal model (STM).

  8. Near-infrared spectrophotometry of the satellites and rings of Uranus

    Science.gov (United States)

    Soifer, B. T.; Neugebauer, G.; Matthews, K.

    1981-01-01

    New spectrophotometry from 1.5 to 2.5 microns is reported for the Uranian satellites Titania, Oberon, and Umbriel. A spectrum of the rings of Uranus from 2.0 to 2.4 microns is also reported. No evidence is found for frost covering the surface of the ring material, consistent with the low albedo of the rings previously reported by Nicholson and Jones (1980). The surfaces of the satellites are found to be covered by dirty water frost. Assuming albedos of the frost and gray components covering the Uranian satellites to be the same as the light and dark faces of Iapetus, radii are derived that are roughly twice those inferred from the assumption of a visual albedo of 0.5.

  9. Molecular Dynamics at Electrical- and Optical-Driven Phase Transitions: Time-Resolved Infrared Studies Using Fourier-Transform Spectrometers

    Science.gov (United States)

    Peterseim, Tobias; Dressel, Martin

    2017-01-01

    The time-dependent optical properties of molecular systems are investigated by step-scan Fourier-transform spectroscopy in order to explore the dynamics at phase transitions and molecular orientation in the milli- and microsecond range. The electrical switching of liquid crystals traced by vibrational spectroscopy reveals a rotation of the molecules with a relaxation time of 2 ms. The photo-induced neutral-ionic transition in TTF-CA takes place by a suppression of the dimerization in the ionic phase and creation of neutral domains. The time-dependent infrared spectra, employed to investigate the domain-wall dynamics, depend on temperature and laser pulse intensity; the relaxation of the spectra follows a stretched-exponential decay with relaxation times in the microsecond range strongly dependent on temperature and laser intensity. We present all details of the experimental setups and thoroughly discuss the technical challenges.

  10. The Micro Fourier Transform Interferometer (muFTIR) - A New Field Spectrometer for Acquisition of Infrared Data of Natural Surfaces

    Science.gov (United States)

    Hook, Simon J.

    1995-01-01

    A lightweight, rugged, high-spectral-resolution interferometer has been built by Designs and Prototypes based on a set of specifications provided by the Jet Propulsion Laboratory and Dr. J. W. Salisbury (Johns Hopkins University). The instrument, the micro Fourier Transform Interferometer (mFTIR), permits the acquisition of infrared spectra of natural surfaces. Such data can be used to validate low and high spectral resolution data acquired remotely from aircraft and spacecraft in the 3-5 mm and 8-14 mm atmospheric window. The instrument has a spectral resolutions of 6 wavenumbers, weighs 16 kg including batteries and computer, and can be operated easily by two people in the field. Laboratory analysis indicates the instrument is spectrally calibrated to better than 1 wavenumber and the radiometric accuracy is <0.5 K if the radiances from the blackbodies used for calibration bracket the radiance from the sample.

  11. FIRAS optical alignment and performance during vibration qualification and cryogenic cycling. [Far InfraRed Absolute Spectrometer

    Science.gov (United States)

    Hagopian, John G.

    1989-01-01

    NASA's Cosmic Background Explorer (COBE) is designed to investigate the Cosmic Background Radiation (CBR), that permeates the universe as a consequence of the Big Bang. This 3 degree Kelvin radiation is a fossil that contains much information about the early universe. The Far Infrared Absolute Spectrophotometer (FIRAS), will investigate the spectral isotropy of this ancient remnant and look for clues as to the subsequent evolution of the universe. The instrument is a cryogenically cooled, modified Michelson interferometer which operates in the 1 cm to 100 micron wavelength range. FIRAS is designed to provide absolute spectral information, therefore, all possible perturbations to the instrument response must be investigated to minimize distortions of the data. This paper discusses the methodology and resultant variations in the instrument performance noted during room temperature, and liquid nitrogen, (LN2) temperature vibration qualification. Reference alignment shifts in critical components such as the instrument wire-grid beamsplitter are correlated to changes in the instrument spectral response.

  12. Near-infrared analysis of fennel (Foeniculum vulgare Miller) on different spectrometers--basic considerations for a reliable network.

    Science.gov (United States)

    Steuer, Boris; Schulz, Hartwig

    2003-01-01

    The aim of this study was to investigate the accuracy and transferability of near-infrared (NIR) calibrations for estimating the content and composition of the volatile fraction in fennel fruits (Foeniculum vulgare Miller) as an example of medicinal and spice plants. A master calibration with spectra obtained on a scanning monochromator was generated using 345 samples from three different harvests (1997-1999). A subset of 70 samples from 1999 was also measured on a dispersive grating and a scanning diode array system to gain an insight into the influence of sample presentation and scanning techniques. For all instruments, calibrations with standard errors in the range of the reference method were achieved. Furthermore the influence of storage on NIR spectra and, additionally, the potential of transferring spectra between both scanning monochromators was studied.

  13. Molecular Dynamics at Electrical- and Optical-Driven Phase Transitions: Time-Resolved Infrared Studies Using Fourier-Transform Spectrometers

    Science.gov (United States)

    Peterseim, Tobias; Dressel, Martin

    2016-06-01

    The time-dependent optical properties of molecular systems are investigated by step-scan Fourier-transform spectroscopy in order to explore the dynamics at phase transitions and molecular orientation in the milli- and microsecond range. The electrical switching of liquid crystals traced by vibrational spectroscopy reveals a rotation of the molecules with a relaxation time of 2 ms. The photo-induced neutral-ionic transition in TTF-CA takes place by a suppression of the dimerization in the ionic phase and creation of neutral domains. The time-dependent infrared spectra, employed to investigate the domain-wall dynamics, depend on temperature and laser pulse intensity; the relaxation of the spectra follows a stretched-exponential decay with relaxation times in the microsecond range strongly dependent on temperature and laser intensity. We present all details of the experimental setups and thoroughly discuss the technical challenges.

  14. Comparison of ground-based FTIR and Brewer O3 total column with data from two different IASI algorithms and from OMI and GOME-2 satellite instruments

    OpenAIRE

    Blumenstock, T.; J.-M. Flaud; P. Chelin; Eremenko, M.; A. Redondas; Hase, F.; Schneider, M; C. Viatte; Orphal, J

    2011-01-01

    An intercomparison of ozone total column measurements derived from various platforms is presented in this work. Satellite data from Infrared Atmospheric Sounding Interferometer (IASI), Ozone Monitoring Instrument (OMI) and Global Ozone Monitoring Experiment (GOME-2) are compared with data from two ground-based spectrometers (Fourier Transform Infrared spectrometer FTIR and Brewer), located at the Network for Detection of Atmospheric Composition Change (NDACC) super-site of Izaña (Tenerife), m...

  15. Micro Hadamard Transform Near-Infrared Spectrometer%微型MOEMS阿达玛变换近红外光谱仪

    Institute of Scientific and Technical Information of China (English)

    张智海; 莫祥霞; 郭媛君; 王伟

    2011-01-01

    提出一种运用微光机电系统(micro-opto-electro-mechanical systems,MOEMS)闪耀光栅,动态产生阿达玛变换模版的微型近红外光谱仪.它具有体积小、价格低、扫描速度快等突出优点.分析了这种新型近红外光谱仪的结构和工作原理,通过对MOEMS闪耀光栅编程,动态生成了 63阶阿达玛模版.实验得到的光谱波形与岛津光谱仪测量结果吻合.检测波长范围为900~1 500nm,分辨率为19nm,单次扣描时间2.4s,信噪比为44.67:1,光路尺寸为70 mm×130 mm,总体重量<1kg,符合实时、便携的要求.%A new type micro Hadanard transform (HT) near-infrared (NIR) spectrometer is proposed in the present paper. It has a MOEMS (Micro-Opto-Electro-Mechanical Systems) blazed grating HT mask. It has merits of compactness, agility of dynamic mask generation and high scan speed. The structure and theory of this spectrometer are analyzed. The 63-order Hadarmard-S matrix and mask are designed. The mask is dynamically generated by program of MOEMS blazed gratings. The spectrum is in agreement with that measured by Shimadzu spectrometer in experiments. It has a wavelength range between 900 and 1 700 nm, spectral resolution of 19 nm, single scan time of 2.4 s, SNR of 44. 67 : 1, optical path of 70 mm× 130 mm, and weight under 1 kg. It can meet the requirement of real time detection and portable application.

  16. USING OF THE MULTITEMPORAL THERMAL INFRARED SATELLITE IMAGERY FOR NATURAL AREAS MAPPING (CASE OF MENDELEEV VOLCANO

    Directory of Open Access Journals (Sweden)

    M. Y. Grishchenko

    2014-01-01

    Full Text Available In the paper authors examine the mountain group of Mendeleev volcano situated on the Kunashir island, Kuril archipelago, Russia. Ground observations were led to examine the vegetation cover of the area as well as its typical landscapes. The other type of used data is Landsat imagery. Images were combined into multitemporal thermal infrared and multispectral pictures, which were classified to reveal the heterogeneity of the study area. Ground observations and comparison of the classification results with landscape map derive that the multitemporal thermal infrared image classification result describes better the vegetation cover structure of the area and particularity of its typical landscapes distribution. It leads to the proposition that miltitemporal thermal infrared imagery can be used to refine landscape and vegetation cover contours. 

  17. Optimized data analysis algorithm for on-site chemical identification using a hand-held attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer.

    Science.gov (United States)

    Ron, Izhar; Zaltsman, Amalia; Kendler, Shai

    2013-12-01

    On-site identification of organic compounds in the presence of interfering materials using a field-portable attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer is presented. Identification is based on an algorithm that compares the analyte's infrared absorption spectrum with the reference spectra. The comparison is performed at several predetermined frequencies, and a similarity value (distance) between the measured and the reference spectra is calculated either at each frequency individually, or, alternatively, the average distance for all frequencies is calculated. The examined frequencies are selected to give the best contrast between the target materials of interest. In this study, the algorithm was optimized to identify three common chemical warfare agents (CWAs): O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioic acid (VX), sarin (GB), and sulfur mustard (bis(2-chloroethyl) sulfide) (HD), in the presence of field-related interfering materials (fuels, water, and dust). Receiver operating characteristics analysis was performed in order to determine the probabilities for detection (PD) and for false alerts (PF). Challenging the algorithm with a set of data that contains mixtures of CWAs and interfering materials resulted in PD of 90% and PF of 0%, 0%, and 1% for VX, GB, and HD, respectively, using the average distance approach, which was found to be much more effective than analyzing each frequency individually. This finding was validated for all possible combinations of 2-7 peaks per material. It is suggested that this algorithm provides a reliable mean for the identification of a predetermined set of target analytes and interfering materials.

  18. Development of Multi-Membrane Near-Infrared Diode Mass Spectrometer for Field Analysis of Aromatic Hydrocarbons

    Science.gov (United States)

    Mach, Phillip M.; Wright, Kenneth C.; Verbeck, Guido F.

    2015-02-01

    Membrane Inlet Mass Spectrometry (MIMS) is a technique that incorporates a semi-permeable membrane selective for differing organic molecules and chemistries. This eliminates the need for time-consuming sample preparation and facilitates near instantaneous analysis. This study will examine how the front end of MIMS incorporates three dual inlet ports, allowing for differing MIMS materials and selectivity for specific environments. Polydimethylsiloxane (PDMS) membranes have proven to be selective of benzene, toluene, and xylene (BTX) as well as aromatic hydrocarbons that are common in petroleum products while remaining selective against the aliphatic chains. PDMS has proven to be a successful choice of membrane with high permeability in atmospheric environments. In addition, polycyclic aromatic hydrocarbons (PAHs) such as acenaphthene, acenapthylene, naphthalene, and fluorene have recently been detected to the 5 ppb level in a nitrogen atmosphere with our current configuration. This preliminary work provides proof of concept using near-infrared laser diodes that act upon the membrane to increase its permeability and provide higher sensitivity of aromatic samples.

  19. Application Fourier transform near infrared spectrometer in rapid estimation of soluble solids content of intact citrus fruits

    Institute of Scientific and Technical Information of China (English)

    LU Hui-shan; XU Hui-rong; YING Yi-bin; FU Xia-ping; YU Hai-yan; TIAN Hai-qing

    2006-01-01

    Nondestructive method of measuring soluble solids content (SSC) of citrus fruits was developed using Fourier transform near infrared reflectance (FT-NIR) measurements collected through optics fiber. The models describing the relationship between SSC and the NIR spectra of citrus fruits were developed and evaluated. Different spectra correction algorithms (standard normal variate (SNV), multiplicative signal correction (MSC)) were used in this study. The relationship between laboratory SSC and FT-NIR spectra of citrus fruits was analyzed via principle component regression (PCR) and partial least squares (PLS) regression method. Models based on the different spectral ranges were compared in this research. The first derivative and second derivative were applied to all spectra to reduce the effects of sample size, light scattering, instrument noise, etc. Different baseline correction methods were applied to improve the spectral data quality. Among them the second derivative method after baseline correction produced best noise removing capability and yielded optimal calibration models. A total of 170 NIR spectra were acquired; 135 NIR spectra were used to develop the calibration model; the remaining spectra were used to validate the model. The developed PLS model describing the relationship between SSC and NIR reflectance spectra could predict SSC of 35 samples with correlation coefficient of 0.995 and RMSEP of 0.79°Brix.

  20. A 100 kHz Time-Resolved Multiple-Probe Femtosecond to Second Infrared Absorption Spectrometer.

    Science.gov (United States)

    Greetham, Gregory M; Donaldson, Paul M; Nation, Charlie; Sazanovich, Igor V; Clark, Ian P; Shaw, Daniel J; Parker, Anthony W; Towrie, Michael

    2016-04-01

    We present a dual-amplifier laser system for time-resolved multiple-probe infrared (IR) spectroscopy based on the ytterbium potassium gadolinium tungstate (Yb:KGW) laser medium. Comparisons are made between the ytterbium-based technology and titanium sapphire laser systems for time-resolved IR spectroscopy measurements. The 100 kHz probing system provides new capability in time-resolved multiple-probe experiments, as more information is obtained from samples in a single experiment through multiple-probing. This method uses the high repetition-rate probe pulses to repeatedly measure spectra at 10 µs intervals following excitation allowing extended timescales to be measured routinely along with ultrafast data. Results are presented showing the measurement of molecular dynamics over >10 orders of magnitude in timescale, out to 20 ms, with an experimental time response of <200 fs. The power of multiple-probing is explored through principal component analysis of repeating probe measurements as a novel method for removing noise and measurement artifacts.

  1. Micro spatial modulation Fourier transform infrared spectrometer%空间调制微型傅里叶变换红外光谱仪研究

    Institute of Scientific and Technical Information of China (English)

    梁静秋; 梁中翥; 吕金光; 秦余欣; 田超; 王维彪

    2015-01-01

    According to the urgent requirement to the microminiature, lightweight, and staticize on Fourier transform infrared spectrometer in the field of environment, medical treatment, space exploration, meteorolo-gy, military and security, a spatial modulation Fourier transform infrared spectrometer based on MOEMS micro multi-step mirrors( MMSMs) was proposed.In theory, the physical model and the optical principle of spatial modulation Fourier transform infrared spectrometer was built and researched.A method of leaving extra pat-ches in the boundary to suppress diffraction noise was put forward, and an algorithm based on the least-squares approximation was proposed to correct sampling error.According to the analyzing on the fabrication accuracy of MMSMs, the dispersion characteristics and the transmission efficiency of the beam splitter, the design method and the technical parameters were determined.In the core technology, three different kinds of manufacture method of MMSMs were put forward.By ways of analyzing the origin of the error, the tolerance of two MMSMs was given.The two MMSMs were completed by the method of electroform, positioning of the growth multilayer film, and inclined plane method respectively.In the system design, the infrared collimation system and ima-ging system were designed and manufactured.According to modeling simulation of the whole machine system, the source of stray light noise was analyzed.In the interferogram processing, using zero crossing sampling model and image segmentation algorithm, the sampling sequence was obtained.By interpolation, zero filling, continuation and convolution of the interference sequence, the phase error of spectrum was corrected.After that, the spectrum was obtained from the interferogram via discrete Fourier transform.Finally, the integration and coupling technology of the system were researched.The characteristics of infrared spectrometer developed in this project were as follows:Firstly, the moving mirror driven

  2. Hydrogen Isotopic Composition of Arctic and Atmospheric CH4 Determined by a Portable Near-Infrared Cavity Ring-Down Spectrometer with a Cryogenic Pre-Concentrator

    Science.gov (United States)

    Chen, Y.; Lehmann, Kevin K.; Peng, Y.; Pratt, L. M.; White, J. R.; Cadieux, S. B.; Sherwood Lollar, B.; Lacrampe-Couloume, G.; Onstott, T. C.

    2016-10-01

    In this study, near-infrared continuous wave cavity ring-down spectroscopy was applied to the measurement of the δ2H of methane (CH4). The cavity ring-down spectrometer (CRDS) system consisted of multiple DFB laser diodes to optimize selection of spectral line pairs. By rapidly switching measurements between spectral line peaks and the baseline regions, the long-term instrumental drift was minimized, substantially increasing measurement precision. The CRDS system coupled with a cryogenic pre-concentrator measured the δ2H of terrestrial atmospheric CH4 from 3 standard liters of air with a precision of ±1.7‰. The rapidity with which both C and H isotopic measurements of CH4 can be made with the CRDS will enable hourly monitoring of diurnal variations in terrestrial atmospheric CH4 signatures that can be used to increase the resolution of global climate models for the CH4 cycle. Although the current instrument is not capable of measuring the δ2H of 10 ppbv of martian CH4, current technology does exist that could make this feasible for future spaceflight missions. As biological and abiotic CH4 sources have overlapping carbon isotope signatures, dual-element (C and H) analysis is key to reliable differentiation of these sources. Such an instrument package would therefore offer improved ability to determine whether or not the CH4 recently detected in the martian atmosphere is biogenic in origin.

  3. Temperature-Dependent Refractive Index Measurements of Caf2, Suprasil 3001, and S-FTM16 for the Euclid Near Infrared Spectrometer and Photometer

    Science.gov (United States)

    Leviton, Douglas B.; Miller, Kevin H.; Quijada, Manuel A.; Grupp, Frank D.

    2015-01-01

    Using the Cryogenic High Accuracy Refraction Measuring System (CHARMS) at NASA's Goddard Space Flight Center, we measured absolute refractive indices at temperatures from 100 to 310 K at wavelengths from 0.42 to 3.6 microns for CaF2, Suprasil 3001 fused silica, and S-FTM16 glass in support of lens designs for the Near Infrared Spectrometer and Photometer (NISP) for ESA's Euclid dark energy mission. We report absolute refractive index, dispersion (dn/d?), and thermo-optic coefficient (dn/dT) for these materials. In this study, materials from different melts were procured to understand index variability in each material. We provide temperature-dependent Sellmeier coefficients based on our data to allow accurate interpolation of index to other wavelengths and temperatures. For calcium fluoride (CaF2) and S-FTM16, we compare our current measurements with CHARMS measurements of these materials made in the recent past for other programs. We also compare Suprasil 3001's indices to those of other forms of fused silica we have measured in CHARMS.

  4. Retrospective assessment of macrophytic communities in southern Lake Garda (Italy from in situ and MIVIS (Multispectral Infrared and Visible Imaging Spectrometer data

    Directory of Open Access Journals (Sweden)

    Claudia Giardino

    2012-01-01

    Full Text Available In situ and hyperspectral MIVIS (Multispectral Infrared and Visible Imaging Spectrometer images acquired over a period of 13 years are used to assess changes in macrophyte colonization patterns in the coastal zones of the Sirmione Peninsula in the southern part of Lake Garda (Italy. In situ data (abundance, cover density and diversity of macrophyte communities and MIVIS-derived maps of colonized substrates are analyzed by considering the variability of the main hydrological and physicochemical variables in order to indicate the main factors that explain the spatiotemporal variability of macrophyte communities. The results show a considerable modification in terms of macrophyte structural complexity and colonized areas. Almost 98% of macrophyte meadows (in particular communities with a density of over 70% are lost and subsequently replaced by moderate to extremely rare communities with density from 10% to 40%. Well-established submerged macrophytes are replaced by de-structured communities characterized by moderate to scarce density: on average lower than 30%. The study indicates that macrophyte distribution along the littoral zone of the Sirmione Peninsula is certainly linked to water transparency and water level fluctuation. The results also indicate that the worsening of eutrophication may be associated with the gradual disappearance of macrophyte meadows, but may also be accelerated by herbivorous aquatic birds grazing there. Lastly, the increasing frequency and number of catamaran tours could be considered a threat for the stability of these valuable communities.

  5. Configurable slit-mask unit of the Multi-Object Spectrometer for Infra-Red Exploration for the Keck telescope: integration and tests

    Science.gov (United States)

    Spanoudakis, Peter; Giriens, Laurent; Henein, Simon; Lisowski, Leszek; O'Hare, Aidan; Onillon, Emmanuel; Schwab, Philippe; Theurillat, Patrick

    2008-07-01

    A Configurable Slit Unit (CSU) has been developed for the Multi-Object Spectrometer for Infra-Red Exploration (MOSFIRE) instrument to be installed on the Keck 1 Telescope on Mauna Kea, Hawaii. MOSFIRE will provide NIR multi-object spectroscopy over a field of view of 6.1' x 6.1'. The reconfigurable mask allows the formation of 46 optical slits in a 267 x 267 mm2 field of view. The mechanism is an evolution of a former prototype designed by CSEM and qualified for the European Space Agency (ESA) as a candidate for the slit mask on NIRSpec for the James Webb Space Telescope (JWST). The CSU is designed to simultaneously displace masking bars across the field-of-view (FOV) to mask unwanted light. A set of 46 bar pairs are used to form the MOSFIRE focal plane mask. The sides of the bars are convoluted so that light is prevented from passing between adjacent bars. The slit length is fixed (5.1 mm) but the width is variable down to 200 μm with a slit positioning accuracy of +/- 18 μm. A two-bar prototype mechanism was designed, manufactured and cryogenically tested to validate the modifications from the JWST prototype. The working principle of the mechanism is based on an improved "inch-worm" stepping motion of 92 masking bars forming the optical mask. Original voice coil actuators are used to drive the various clutches. The design makes significant use of flexure structures.

  6. Reconstruction of an infrared band of meteorological satellite imagery with abductive networks

    Science.gov (United States)

    Singer, Harvey A.; Cockayne, John E.; Versteegen, Peter L.

    1995-01-01

    As the current fleet of meteorological satellites age, the accuracy of the imagery sensed on a spectral channel of the image scanning system is continually and progressively degraded by noise. In time, that data may even become unusable. We describe a novel approach to the reconstruction of the noisy satellite imagery according to empirical functional relationships that tie the spectral channels together. Abductive networks are applied to automatically learn the empirical functional relationships between the data sensed on the other spectral channels to calculate the data that should have been sensed on the corrupted channel. Using imagery unaffected by noise, it is demonstrated that abductive networks correctly predict the noise-free observed data.

  7. Satellite-based forest monitoring: spatial and temporal forecast of growing index and short-wave infrared band.

    Science.gov (United States)

    Bayr, Caroline; Gallaun, Heinz; Kleb, Ulrike; Kornberger, Birgit; Steinegger, Martin; Winter, Martin

    2016-04-18

    For detecting anomalies or interventions in the field of forest monitoring we propose an approach based on the spatial and temporal forecast of satellite time series data. For each pixel of the satellite image three different types of forecasts are provided, namely spatial, temporal and combined spatio-temporal forecast. Spatial forecast means that a clustering algorithm is used to group the time series data based on the features normalised difference vegetation index (NDVI) and the short-wave infrared band (SWIR). For estimation of the typical temporal trajectory of the NDVI and SWIR during the vegetation period of each spatial cluster, we apply several methods of functional data analysis including functional principal component analysis, and a novel form of random regression forests with online learning (streaming) capability. The temporal forecast is carried out by means of functional time series analysis and an autoregressive integrated moving average model. The combination of the temporal forecasts, which is based on the past of the considered pixel, and spatial forecasts, which is based on highly correlated pixels within one cluster and their past, is performed by functional data analysis, and a variant of random regression forests adapted to online learning capabilities. For evaluation of the methods, the approaches are applied to a study area in Germany for monitoring forest damages caused by wind-storm, and to a study area in Spain for monitoring forest fires.

  8. A comparison of minor trace gas retrievals from the Tropospheric Emission Spectrometer (TES) and the Infrared Atmospheric Sounding Interferometer (IASI)

    Science.gov (United States)

    Cady-Pereira, K. E.; Shephard, M. W.; Henze, D. K.; Millet, D. B.; Gombos, D.; Van Damme, M.; Clarisse, L.; Coheur, P. F.; Pommier, M.; Clerbaux, C.

    2014-12-01

    The advent of hyperspectral infrared instruments orbiting the Earth has allowed for detecting and measuring numerous trace gas species that play important roles in atmospheric chemistry and impact air quality, but for which there is a dearth of information on their distribution and temporal variability. Here we will present global and regional comparisons of measurements from the NASA TES and the European MetOp IASI instruments of three of these gases: ammonia (NH3), formic acid (HCOOH) and methanol (CH3OH). Ammonia is highly reactive and thus very variable in space and time, while the sources and sinks of methanol and formic acid are poorly quantified: thus space-based measurements have the potential of significantly increasing our knowledge of the emissions and distributions of these gases. IASI and TES have many similarities but some significant differences. TES has significantly higher spectral resolution (0.06 cm-1), and its equator crossing times are ~1:30 am and 1:30 pm, local time, while IASI has lower resolution (0.5 cm-1) and an earlier equator crossing time (9:30 am and 9:30 pm), which leads to lower thermal contrast; however IASI provides much greater temporal and spatial coverage due to its cross-track scanning. Added to the instrumental differences are the differences in retrieval algorithms. The IASI team uses simple but efficient methods to estimate total column amounts of the species above, while the TES team performs full optimal estimation retrievals. We will compare IASI and TES total column measurements averaged on a 2.5x2.5 degree global grid for each month in 2009, and we will examine the seasonal cycle in some regions of interest, such as South America, eastern China, and the Midwest and the Central Valley in the US. In regions where both datasets are in agreement this analysis will provide confidence that the results are robust and reliable. In regions where there is disagreement we will look for the causes of the discrepancies, which will

  9. An Autonomous System to Take Angular Thermal-Infrared Measurements for Validating Satellite Products

    OpenAIRE

    Raquel Niclòs; José A. Valiente; Maria J. Barberà; César Coll

    2015-01-01

    An autonomous system for field land surface temperature (LST) measurements taken at different observation angles was developed to be deployed easily at any conventional meteorological tower station. The system permits ground-truth data to be acquired on a continuous basis, and angularly scans land and sky hemispheres with a single thermal-infrared (TIR) radiometer. This paper describes the autonomous angular system and the methodology to assess ground-truth LST and relative-to-nadir emissivit...

  10. Specification for an Infrared Satellite Surveillance System for the Detection of Aircraft

    Science.gov (United States)

    1987-11-01

    In the monolithic IRCCD, the infrared sensitive substrate is either e narrow bandgap semiconductor or an extrinsic semiconductor with appropriate...thermally generated to bring the potential well into thermal equilibrium. Clock Feedt.hrough This noise is due to capacitance coupling Noise from the...Noise This noise is associated with a MOSFET of a given transconductance. Detector This noise is variations across the video Uniformity Noise output

  11. Long-Term Record of Arctic and Antarctic Sea and Ice Surface Temperatures from Thermal Infrared Satellite Sensors

    Science.gov (United States)

    Luis, Cristina; Dybkjær, Gorm; Eastwood, Steinar; Tonboe, Rasmus; Høyer, Jacob

    2015-04-01

    Surface temperature is among the most important variables in the surface energy balance equation and it significantly affects the atmospheric boundary layer structure, the turbulent heat exchange and, over ice, the ice growth rate. Here we measure the surface temperature using thermal infrared sensors from 10-12 µm wavelength, a method whose primary limitation over sea ice is the detection of clouds. However, in the Arctic and around Antarctica there are very few conventional observations of surface temperature from buoys, and it is sometimes difficult to determine if the temperature is measured at the surface or within the snowpack, the latter of which often results in a warm bias. To reduce this bias, much interest is being paid to alternative remote sensing methods for monitoring high latitude surface temperature. We used Advanced Very High Resolution Radiometer (AVHRR) global area coverage (GAC) data to produce a high latitude sea surface temperature (SST), ice surface temperature (IST) and ice cap skin temperature dataset spanning 27 years (1982-2009). This long-term climate record is the first of its kind for IST. In this project we used brightness temperatures from the infrared channels of AVHRR sensors aboard NOAA and Metop polar-orbiting satellites. Surface temperatures were calculated using separate split window algorithms for day SST, night SST, and IST. The snow surface emissivity across all angles of the swath were simulated specifically for all sensors using an emission model. Additionally, all algorithms were tuned to the Arctic using simulated brightness temperatures from a radiative transfer model with atmospheric profiles and skin temperatures from European Centre for Medium-Range Forecasts (ECMWF) re-analysis data (ERA-Interim). Here we present the results of product quality as compared to in situ measurements from buoys and infrared radiometers, as well as a preliminary analysis of climate trends revealed by the record.

  12. Spatial variability in tropospheric peroxyacetyl nitrate in the tropics from infrared satellite observations in 2005 and 2006

    Science.gov (United States)

    Payne, Vivienne H.; Fischer, Emily V.; Worden, John R.; Jiang, Zhe; Zhu, Liye; Kurosu, Thomas P.; Kulawik, Susan S.

    2017-05-01

    Peroxyacetyl nitrate (PAN) plays a fundamental role in the global ozone budget and is the primary reservoir of tropospheric reactive nitrogen over much of the globe. However, large uncertainties exist in how surface emissions, transport and lightning affect the global distribution, particularly in the tropics. We present new satellite observations of free-tropospheric PAN in the tropics from the Aura Tropospheric Emission Spectrometer. This dataset allows us to test expected spatiotemporal distributions that have been predicted by models but previously not well observed. We compare here with the GEOS-Chem model with updates specifically for PAN. We observe an austral springtime maximum over the tropical Atlantic, a feature that model predictions attribute primarily to lightning. Over northern central Africa in December, observations show strong interannual variability, despite low variation in fire emissions, that we attribute to the combined effects of changes in biogenic emissions and lightning. We observe small enhancements in free-tropospheric PAN corresponding to the extreme burning event over Indonesia associated with the 2006 El Niño.

  13. Monolithic spectrometer

    Science.gov (United States)

    Rajic, Slobodan; Egert, Charles M.; Kahl, William K.; Snyder, Jr., William B.; Evans, III, Boyd M.; Marlar, Troy A.; Cunningham, Joseph P.

    1998-01-01

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

  14. Lava discharge rate estimates from thermal infrared satellite data for Pacaya Volcano during 2004-2010

    Science.gov (United States)

    Morgan, Hilary A.; Harris, Andrew J. L.; Gurioli, Lucia

    2013-08-01

    Pacaya is one of the most active volcanoes in Central America and has produced lava flows frequently since 1961. All effusive activity between 1961 and 2009 was confined by an arcuate collapse scarp surrounding the northern and eastern flanks. However, the recent breaching of this topographic barrier, and the eruption of a large lava flow outside of the main center of activity, have allowed lava to extend into nearby populated areas, indicating the need for assessment and monitoring of lava flow hazards. We investigated whether a commonly used satellite-based model could produce accurate lava discharge rates for the purpose of near-real-time assessment of hazards during future eruptions and to assess the dynamics of this persistently degassing system. The model assumes a linear relationship between active lava flow area and time-averaged discharge rate (TADR) via a simple conversion factor. We calculated the conversion factor via two methods: (1) best-fitting of satellite-derived flow areas to ground-based estimates of lava flow volume, and (2) theoretically via a parameterized model that takes into account the physical properties of the lava. To apply the latter method, we sampled four lava flows and measured density, vesicularity, crystal content, and major element composition. We found the best agreement of conversion factors in the eruption with the most complete satellite coverage, and used data for these flows to define the linear relationship between area and discharge rate. The physical properties of the sampled flows were essentially identical, so that any discrepancy between the two methods of calculating conversion factors must be due to modeling errors or environmental factors unaccounted for by the parameterized model. However, our best-fitting method provides a new means to set the conversion appropriately, and to obtain self-consistent TADRs. We identified two distinct types of effusive activity at Pacaya: Type 1 activity characterized by initially

  15. Compact Grism Spectrometer

    Science.gov (United States)

    Teare, S. W.

    2003-05-01

    Many observatories and instrument builders are retrofitting visible and near-infrared spectrometers into their existing imaging cameras. Camera designs that reimage the focal plane and have the optical filters located in a pseudo collimated beam are ideal candidates for the addition of a spectrometer. One device commonly used as the dispersing element for such spectrometers is a grism. The traditional grism is constructed from a prism that has had a diffraction grating applied on one surface. The objective of such a design is to use the prism wedge angle to select the desired "in-line" or "zero-deviation" wavelength that passes through on axis. The grating on the surface of the prism provides much of the dispersion for the spectrometer. A grism can also be used in a "constant-dispersion" design which provides an almost linear spatial scale across the spectrum. In this paper we provide an overview of the development of a grism spectrometer for use in a near infrared camera and demonstrate that a compact grism spectrometer can be developed on a very modest budget that can be afforded at almost any facility. The grism design was prototyped using visible light and then a final device was constructed which provides partial coverage in the near infrared I, J, H and K astronomical bands using the appropriate band pass filter for order sorting. The near infrared grism presented here provides a spectral resolution of about 650 and velocity resolution of about 450 km/s. The design of this grism relied on a computer code called Xspect, developed by the author, to determine the various critical parameters of the grism. This work was supported by a small equipment grant from NASA and administered by the AAS.

  16. Geostationary Satellite (GOES) Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from radiometer instruments on SMS (ATS) and GOES satellites in geostationary orbit. These satellites produced...

  17. Time-resolved visible/near-infrared spectrometric observations of the Galaxy 11 geostationary satellite

    Science.gov (United States)

    Bédard, Donald; Wade, Gregg A.

    2017-01-01

    Time-resolved spectrometric measurements of the Galaxy 11 geostationary satellite were collected on three consecutive nights in July 2014 with the 1.6-m telescope at the Observatoire du Mont-Mégantic in Québec, Canada. Approximately 300 low-resolution spectra (R ≈ 700 , where R = λ / Δλ) of the satellite were collected each night, covering a spectral range between 425 and 850 nm. The two objectives of the experiment were to conduct material-type identification from the spectra and to study how the spectral energy distribution inferred from these measurements varied as the illumination and observation geometry changed on nightly timescales. We present results that indicate the presence of a highly reflective aluminized surface corresponding to the solar concentrator arrays of the Galaxy 11 spacecraft. Although other material types could not be identified using the spectra, the results showed that the spectral energy distribution of the reflected sunlight from the Galaxy 11 spacecraft varied significantly, in a systematic manner, over each night of observation. The variations were quantified using colour indices calculated from the time-resolved spectrometric measurements.

  18. Analysis on Infrared Spectrometer System Specification for Atmospheric Composition Detecting%大气成分探测红外光谱仪系统指标分析

    Institute of Scientific and Technical Information of China (English)

    齐卫红; 尉昊赟; 阴丽娜

    2013-01-01

    由温室气体引起的全球气候变化和环境污染已经受到全世界的广泛关注。进行大气成分探测,对于更好地了解温室效应产生的细节、大气分子的光化学性质对臭氧层的影响以及大气污染机制都具有重要意义。由于大气成分种类较多,其红外吸收光谱密集且复杂,因此大气成分探测仪器需要有较高的光谱分辨能力和信噪比。文章进行了大气成分探测的总体指标需求分析,并据此确定了大气成分探测红外光谱仪的主要技术指标。为了满足指标要求,该光谱仪采用傅里叶变换红外光谱仪的总体方案。通过仪器性能影响因素分析和系统优化,使得该仪器的最终设计结果满足指标要求。%Global climate change and environmental pollution caused by greenhouse gases has received ex-tensive attention all over the world. Detecting atmospheric composition is especial important for a better under-standing of the detail of the green house effect, the influences on the ozonosphere of atmospheric photochemistry, as well as the mechanism of the air pollution. Because the kinds of atmospheric composition and their infrared absorption spectral lines are very dense and complex, atmospheric composition instruments need to have high spectral resolution and high signal-to-noise ratio (SNR). This report briefly introduced the specification require-ment analysis for space atmospheric detecting, and the main specifications of the instrument for space atmospher-ic detecting are defined. For realizing the main specifications, the overall scheme of the instrument adopts Fourier Transform Infrared Spectrometer (FTIRS). The final design of the instrument meets the specifications through influence factor analysis and system optimization. Finally, the measurement result was given.

  19. Far-infrared photometric observations of the outer planets and satellites with Herschel-PACS

    CERN Document Server

    Müller, T G; Nielbock, M; Moreno, R; Klaas, U; Moór, A; Linz, H; Feuchtgruber, H

    2016-01-01

    We present all Herschel PACS photometer observations of Mars, Saturn, Uranus, Neptune, Callisto, Ganymede, and Titan. All measurements were carefully inspected for quality problems, were reduced in a (semi-)standard way, and were calibrated. The derived flux densities are tied to the standard PACS photometer response calibration, which is based on repeated measurements of five fiducial stars. The overall absolute flux uncertainty is dominated by the estimated 5% model uncertainty of the stellar models in the PACS wavelength range between 60 and 210 micron. A comparison with the corresponding planet and satellite models shows excellent agreement for Uranus, Neptune, and Titan, well within the specified 5%. Callisto is brighter than our model predictions by about 4-8%, Ganymede by about 14-21%. We discuss possible reasons for the model offsets. The measurements of these very bright point-like sources, together with observations of stars and asteroids, show the high reliability of the PACS photometer observation...

  20. Comparison of laboratory calibrations of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) at the beginning and end of the first flight season

    Science.gov (United States)

    Vane, Gregg; Chrien, Thomas G.; Reimer, John H.; Green, Robert O.; Conel, James E.

    1988-01-01

    Spectral and radiometric calibrations of AVIRIS are described together with changes in instrument characteristics that occurred during the flight season. These changes include detachment of the optical fibers to two of the four AVIRIS spectrometers, degradation in the optical alignment of the spectrometers due to thermally induced and mechanical warpage, and breakage of a thermal blocking filter in one of the spectrometers. Means of improving the instrument are discussed.

  1. Infrared absorption of gaseous CH{sub 2}BrOO detected with a step-scan Fourier-transform absorption spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yu-Hsuan [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Lee, Yuan-Pern, E-mail: yplee@mail.nctu.edu.tw [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China)

    2014-10-28

    CH{sub 2}BrOO radicals were produced upon irradiation, with an excimer laser at 248 nm, of a flowing mixture of CH{sub 2}Br{sub 2} and O{sub 2}. A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to record temporally resolved infrared (IR) absorption spectra of reaction intermediates. Transient absorption with origins at 1276.1, 1088.3, 961.0, and 884.9 cm{sup −1} are assigned to ν{sub 4} (CH{sub 2}-wagging), ν{sub 6} (O–O stretching), ν{sub 7} (CH{sub 2}-rocking mixed with C–O stretching), and ν{sub 8} (C–O stretching mixed with CH{sub 2}-rocking) modes of syn-CH{sub 2}BrOO, respectively. The assignments were made according to the expected photochemistry and a comparison of observed vibrational wavenumbers, relative IR intensities, and rotational contours with those predicted with the B3LYP/aug-cc-pVTZ method. The rotational contours of ν{sub 7} and ν{sub 8} indicate that hot bands involving the torsional (ν{sub 12}) mode are also present, with transitions 7{sub 0}{sup 1}12{sub v}{sup v} and 8{sub 0}{sup 1}12{sub v}{sup v}, v = 1–10. The most intense band (ν{sub 4}) of anti-CH{sub 2}BrOO near 1277 cm{sup −1} might have a small contribution to the observed spectra. Our work provides information for directly probing gaseous CH{sub 2}BrOO with IR spectroscopy, in either the atmosphere or laboratory experiments.

  2. Near real-time routine for volcano monitoring using infrared satellite data

    Directory of Open Access Journals (Sweden)

    Claudia Spinetti

    2011-12-01

    Full Text Available An Advanced Very-High-Resolution Radiometer (AVHRR routine for hot-spot detection and effusion rate estimation (AVHotRR using AVHRR infrared space-borne images is presented here for the monitoring of active lava flow. AVHotRR uses directly broadcast National Oceanic and Atmospheric Administration (NOAA-AVHRR remotely sensed data. The 2006 summit eruption of Mount Etna provided the opportunity to test the products generated by AVHotRR for monitoring purposes. Low spatial and high temporal resolution products can also be used as inputs of flow models to drive numerical simulations of lava-flow paths and thus to provide quantitative hazard assessment and volcanic risk mitigation.

  3. Hoar crystal development and disappearance at Dome C, Antarctica: observation by near-infrared photography and passive microwave satellite

    Directory of Open Access Journals (Sweden)

    N. Champollion

    2013-08-01

    Full Text Available Hoar crystals episodically cover the snow surface in Antarctica and affect the roughness and reflective properties of the air–snow interface. However, little is known about their evolution and the processes responsible for their development and disappearance despite a probable influence on the surface mass balance and energy budget. To investigate hoar evolution, we use continuous observations of the surface by in situ near-infrared photography and by passive microwave remote sensing at Dome C in Antarctica. From the photography data, we retrieved a daily indicator of the presence/absence of hoar crystals using a texture analysis algorithm. The analysis of this 2 yr long time series shows that Dome C surface is covered almost half of the time by hoar. The development of hoar crystals takes a few days and seems to occur whatever the meteorological conditions. In contrast, the disappearance of hoar is rapid (a few hours and coincident with either strong winds or with moderate winds associated with a change in wind direction from southwest (the prevailing direction to southeast. From the microwave satellite data, we computed the polarisation ratio (i.e. horizontal over vertical polarised brightness temperatures, an indicator known to be sensitive to hoar in Greenland. Photography data and microwave polarisation ratio are correlated, i.e. high values of polarisation ratio which theoretically correspond to low snow density values near the surface are associated with the presence of hoar crystals in the photography data. Satellite data over nearly ten years (2002–2011 confirm that a strong decrease of the polarisation ratio (i.e. signature of hoar disappearance is associated with an increase of wind speed or a change in wind direction from the prevailing direction. The photography data provides, in addition, evidence of interactions between hoar and snowfall. Further adding the combined influence of wind speed and wind direction results in a

  4. Online Visualization and Analysis of Merged Global Geostationary Satellite Infrared Dataset

    Science.gov (United States)

    Liu, Z.; Ostrenga, D.; Leptoukh, G.; Mehta, A.

    2008-12-01

    The NASA Goddard Earth Sciences Data Information Services Center (GES DISC) is home of Tropical Rainfall Measuring Mission (TRMM) data archive. The global merged IR product, also known as, the NCEP/CPC 4-km Global (60°N - 60°S) IR Dataset, is one of TRMM ancillary datasets. They are globally-merged (60°N-60°S) pixel-resolution (4 km) IR brightness temperature data (equivalent blackbody temperatures), merged from all available geostationary satellites (GOES-8/10, METEOSAT-7/5 & GMS). The availability of data from METEOSAT-5, which is located at 63E at the present time, yields a unique opportunity for total global (60°N-60°S) coverage. The GES DISC has collected over 8 years of the data beginning from February of 2000. This high temporal resolution dataset can not only provide additional background information to TRMM and other satellite missions, but also allow observing a wide range of meteorological phenomena from space, such as, mesoscale convection system, tropical cyclones, hurricanes, etc. The dataset can also be used to verify model simulations. Despite that the data can be downloaded via ftp, however, its large volume poses a challenge for many users. A single file occupies about 70 MB disk space and there is a total of ~73,000 files (~4.5 TB) for the past 8 years. Because there is a lack of data subsetting service, one has to download the entire file, which could be time consuming and require a lot of disk space. In order to facilitate data access, we have developed a web prototype, the Global Image ViewER (GIVER), to allow users to conduct online visualization and analysis of this dataset. With a web browser and few mouse clicks, users can have a full access to over 8 year and over 4.5 TB data and generate black and white IR imagery and animation without downloading any software and data. Basic functions include selection of area of interest, single imagery or animation, a time skip capability for different temporal resolution and image size. Users

  5. Global Cloud Detection and Distribution with Night Time using Satellite Infrared Data

    Science.gov (United States)

    Kadosaki, G.; Yamanouchi, T.; Hirasawa, N.

    2007-12-01

    Knowledge of the current climate system is necessary to clearly estimate large-scale global warming and abnormal weather in the future. Net radiation is one of the main factors that influence a climate system. The earth, which is covered by cloud of dozens of surface giving it a high albedo, reflects a large part of solar radiation. In addition, during nights, when the earth's radiation increases, the earth acts as a radiator. There is no doubt that clouds are closely related to the radiation balance. Satellite data analysis is the most useful method to understand cloud climatology. The targets are to establish an algorithm to detect clouds for night term of the earth, and to get to know more about global cloud distribution with night term. Brightness temperature difference of split window channels is used in this method. We decided three thresholds which have some slopes are used in the case of over land, open sea, and snow or ice surface including sea ice, respectively. We examined on some sensors which has difference response function in itself plat home, GLI/ADEOS2, AVHRR/NOAA, MODIS/Terra and Aqua.

  6. Infrared

    Science.gov (United States)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  7. Estimation of soil moisture-thermal infrared emissivity relation in arid and semi-arid environments using satellite observations

    Science.gov (United States)

    Grazia Blasi, Maria; Masiello, Guido; Serio, Carmine; Venafra, Sara; Liuzzi, Giuliano; Dini, Luigi

    2016-04-01

    The retrieval of surface parameters is very important for various aspects concerning the climatological and meteorological context. At this purpose surface emissivity represents one of the most important parameters useful for different applications such as the estimation of climate changes and land cover features. It is known that thermal infrared (TIR) emissivity is affected by soil moisture, but there are very few works in literature on this issue. This study is aimed to analyze and find a relation between satellite soil moisture data and TIR emissivity focusing on arid and semi-arid environments. These two parameters, together with the land surface temperature, are fundamental for a better understanding of the physical phenomena implied in the soil-atmosphere interactions and the surface energy balance. They are also important in several fields of study, such as climatology, meteorology, hydrology and agriculture. In particular, there are several studies stating a correlation between soil moisture and the emissivity at 8-9 μm in desertic soils, which corresponds to the quartz Reststrahlen, a feature which is typical of sandy soils. We investigated several areas characterized by arid or semi-arid environments, focusing our attention on the Dahra desert (Senegal), and on the Negev desert (Israel). For the Dahra desert we considered both in situ, provided by the International Soil Moisture Network, and satellite soil moisture data, from ASCAT and AMSR-E sensors, for the whole year 2011. In the case of the Negev desert soil moisture data are derived from ASCAT observations and we computed a soil moisture index from a temporal series of SAR data acquired by the Cosmo-SkyMed constellation covering a period of six months, from June 2015 to November 2015. For both cases soil moisture data were related to the retrieved TIR emissivity from the geostationary satellite SEVIRI in three different spectral channels, at 8.7 μm, 10.8 μm and 12 μm. A Kalman filter physical

  8. Quantification of the Beauce's Groundwater contribution to the Loire River discharge using satellite infrared imagery

    Directory of Open Access Journals (Sweden)

    E. Lalot

    2015-02-01

    Full Text Available Seven Landsat Thermal InfraRed (TIR images, taken over the period 2000–2010, were used to establish longitudinal temperature profiles of the middle Loire River, where it flows above the Beauce aquifer. Results showed that 75% of the temperature differences, between in situ observations and TIR image based estimations, remained within the ±1 °C interval. The groundwater discharge along the River course was quantified for each identified groundwater catchment areas using a heat budget based on the Loire River temperature variations, estimated from the TIR images. The main discharge area of the Beauce aquifer into the Loire River was located between river kilometers 630 and 650. This result confirms what was obtained using a groundwater budget and spatially locates groundwater input within the Middle sector of the Loire River. According to the heat budgets, groundwater discharge is higher during winter period (13.5 m3 s−1 than during summer (5.3 m3 s−1. Groundwater input is also higher during the flow recession periods of the Loire River.

  9. Global Transients in ultraviolet and red-infrared ranges from data of the "Universitetsky-Tatiana-2" satellite

    CERN Document Server

    Garipov, G K; Klimov, P A; Klimenko, V V; Mareev, E A; Martines, O; Morozenko, V S; Panasyuk, M I; Park, I H; Ponce, E; Salazar, H; Tulupov, V I; Vedenkin, N N; Yashin, I V

    2011-01-01

    Detectors of fast flashes (duration of 1-128 ms) in near ultraviolet (240-400 nm) and red-infrared (>610 nm) ranges on board the "Universitetsky-Tatiana-2" satellite have measured transient luminous events global distribution. Events with number of photons 10^20-5{\\cdot}10^21 radiated in the atmosphere are uniformly distributed over latitudes and longitudes. Events with number of photons more than 5{\\cdot}10^21 are concentrated near the equator above continents. Measured ratio of photons number radiated in red-IR range to photons number radiated in UV related to excitation of nitrogen molecular indicates a high altitude (>50 km) of the atmospheric electric discharges responsible for the observed transients. Series of every minute transients (from 3 to 16 transients in the series) were observed. The detection of transients out of thunderstorm area, in cloudless region- sometimes thousands km away of thunderstorms is remarkable. The obtained data allow us to assume that transient events are not only consequence...

  10. Efficacy of using multiple open-path Fourier transform infrared (OP-FTIR) spectrometers in an odor emission episode investigation at a semiconductor manufacturing plant.

    Science.gov (United States)

    Tsao, Yung-Chieh; Wu, Chang-Fu; Chang, Pao-Erh; Chen, Shin-Yu; Hwang, Yaw-Huei

    2011-08-01

    This study evaluated the efficacy of simultaneously employing three open-path Fourier transform infrared (OP-FTIR) spectrometers with 3-day consecutive monitoring, using an odor episode as an example. The corresponding monitoring paths were allocated among the possible emission sources of a semiconductor manufacturing plant and the surrounding optoelectronic and electronic-related factories, which were located in a high-tech industrial park. There was a combined total odor rate of 43.9% for the three monitoring paths, each comprised of 736 continuous 5-minute monitoring records and containing detectable odor compounds, such as ammonia, ozone, butyl acetate, and propylene glycol monomethyl ether acetate (PGMEA). The results of the logistic regression model indicated that the prevailing south wind and the OP-FTIR monitoring path closest to the emission source in down-wind direction resulted in a high efficacy for detecting odorous samples with odds ratios (OR) of 3.8 (95% confidence interval (CI): 2.9-5.0) and 5.1 (95% CI: 3.6-7.2), respectively. Meanwhile, the odds ratio for detecting ammonia odorous samples was 7.5 for Path II, which was downwind closer to the possible source, as compared to Path III, downwind far away from the possible source. PGMEA could not be monitored at Path II but could be at Path III, indicating the importance of the monitoring path and flow ejection velocities inside the stacks on the monitoring performance of OP-FTIR. Besides, an odds ratio of 5.1 for odorous sample detection was obtained with south prevailing wind comprising 65.0% of the monitoring time period. In general, it is concluded that OP-FTIR operated with multiple paths simultaneously shall be considered for investigation on relatively complicated episodes such as emergency of chemical release, multiple-source emission and chemical monitoring for odor in a densely populated plant area to enhance the efficacy of OP-FTIR monitoring. Copyright © 2011 Elsevier B.V. All rights

  11. Satellite observation of lowermost tropospheric ozone by multispectral synergism of IASI thermal infrared and GOME-2 ultraviolet measurements over Europe

    Science.gov (United States)

    Cuesta, J.; Eremenko, M.; Liu, X.; Dufour, G.; Cai, Z.; Hoepfner, M.; von Clarmann, T.; Sellitto, P.; Foret, G.; Gaubert, B.; Beekmann, M.; Orphal, J. J.; Chance, K.; Spurr, R. J.; Flaud, J.

    2013-12-01

    Lowermost tropospheric ozone is a major factor determining air quality, which directly affects human health in megacities and causes damages to ecosystems. Monitoring tropospheric ozone is a key societal issue which can be addressed at the regional scale by spaceborne observation. However, current satellite retrievals of tropospheric ozone using uncoupled either ultraviolet (UV) or thermal infrared (TIR) observations show limited sensitivity to ozone at the lowermost troposphere (LMT, up to 3 km asl of altitude above sea level), which is the major concern for air quality. In this framework, we have developed a new multispectral approach for observing lowermost tropospheric ozone from space by synergism of atmospheric TIR radiances observed by IASI and earth UV reflectances measured by GOME-2. Both instruments are onboard the series of MetOp satellites (in orbit since 2006 and expected until 2022) and their scanning capabilities offer global coverage every day, with a relatively fine ground pixel resolution (12-km-diameter pixels spaced by 25 km for IASI at nadir). Our technique uses altitude-dependent Tikhonov-Phillips-type constraints, which optimize sensitivity to lower tropospheric ozone. It integrates the VLIDORT and KOPRA radiative transfer codes for simulating UV reflectance and TIR radiance, respectively. We have used our method to analyze real observations over Europe during an ozone pollution episode in the summer of 2009. The results show that the multispectral synergism of IASI (TIR) and GOME-2 (UV) enables the observation of the spatial distribution of ozone plumes in the LMT, in good agreement with the CHIMERE regional chemistry-transport model. In this case study, when high ozone concentrations extend vertically above 3 km asl, they are similarly observed over land by both the multispectral and IASI retrievals. On the other hand, ozone plumes located below 3 km asl are only clearly depicted by the multispectral retrieval (both over land and over ocean

  12. Satellite chartography of atmospheric methane from SCIAMACHY on board ENVISAT: analysis of the years 2003 and 2004

    NARCIS (Netherlands)

    Frankenberg, C.; Meirink, J.F.|info:eu-repo/dai/nl/181777592; Bergamaschi, P.; Goede, A.P.H.; Heimann, M.; Körner, S.; Platt, U.; van Weele, M.; Wagner, T.

    2006-01-01

    The UV/Vis/near infrared spectrometer SCIAMACHY on board the European ENVISAT satellite enables total column retrieval of atmospheric methane with high sensitivity to the lower troposphere. The vertical column density of methane is converted to column averaged mixing ratio by using carbon dioxide

  13. Retrieval of SO2 from thermal infrared satellite measurements: correction procedures for the effects of volcanic ash

    Directory of Open Access Journals (Sweden)

    S. Corradini

    2009-05-01

    Full Text Available The simultaneous presence of SO2 and ash in a volcanic plume can lead to a significant error in the SO2 column abundance retrieval when multispectral Thermal InfraRed (TIR data are used. The ash particles within the plume with effective radii from 1 to 10 μm reduce the Top Of Atmosphere (TOA radiance in the entire TIR spectral range, including the channels used for SO2 retrieval. The net effect is a significant SO2 overestimation. In this work the interference of ash is discussed and two correction procedures for satellite SO2 volcanic plume retrieval in the TIR spectral range are developed to achieve an higher computational speed and a better accuracy. The ash correction can be applied when the sensor spectral range includes the 7.3 and/or 8.7 μm SO2 absorption bands, and the split window bands centered around 11 and 12 μm required for ash retrieval. This allows the possibility of simultaneous estimation of both volcanic SO2 and ash in the same data set. The proposed ash correction procedures have been applied to the Moderate Resolution Imaging Spectroradiometer (MODIS and the Spin Enhanced Visible and Infrared Imager (SEVIRI measurements. Data collected during the 24 November 2006 Mt. Etna eruption have been used to illustrate the technique. The SO2 and ash estimation is carried out by using a best weighted least squares fit method and the Brightness Temperature Difference (BTD procedures, respectively. The simulated TOA radiance Look-Up Table (LUT needed for the SO2 column abundance and the ash retrievals have been computed using the MODTRAN 4 Radiative Transfer Model. The results show the importance of the ash correction on SO2 retrievals at 8.7 μm, where the corrected SO2 column abundance values are less than 50% of the uncorrected values. The ash correction on SO2 retrieval at 7.3 μm is much less important and only significant for low SO2 column abundances. Results also show that the simplified and faster correction procedure

  14. Retrieval of SO2 from thermal infrared satellite measurements: correction procedures for the effects of volcanic ash

    Directory of Open Access Journals (Sweden)

    A. J. Prata

    2009-02-01

    Full Text Available The simultaneous presence of SO2 and ash in a volcanic plume can lead to a significant error in the SO2 columnar abundance retrieval when multispectral Thermal InfraRed (TIR data are used. The ash particles within the plume with effective radii (from 1 to 10 μm reduce the Top Of Atmosphere (TOA radiance in the entire TIR spectral range, including the channels used for SO2 retrieval. The net effect is a significant SO2 overestimation. In this work the interference of ash is discussed and two correction procedures for satellite SO2 volcanic plume retrieval in the TIR spectral range are developed to achieve an higher computation speed and a better accuracy. The ash correction can be applied when the sensor spectral range includes the 7.3 and/or 8.7 μm SO2 absorption bands, and the split window bands centered around 11 and 12 μm required for ash retrieval. This allows the possibility of a simultaneous estimation of both volcanic SO2 and ash in the same data set. The proposed ash correction procedures have been applied to the Moderate Resolution Imaging Spectroradiometer (MODIS and the Spin Enhanced Visible and Infrared Imager (SEVIRI measurements. Data collected during the 24 November 2006 Mt. Etna eruption have been used to illustrate the technique. The SO2 and ash estimations are carried out by using a least squares fit method and the Brightness Temperature Difference (BTD procedures, respectively. The simulated TOA radiance Look-Up Table (LUT needed for the SO2 columnar abundance and the ash retrievals have been computed using the MODTRAN 4 Radiative Transfer Model. The results show the importance of the ash correction on SO2 retrieval at 8.7 μm – the SO2 columnar abundance corrected by the ash influence is less than one half of the values retrieved without the correction. The ash correction on SO2 retrieval at 7.3 μm is much less important and only significant for low SO2 columnar abundances. Results also show that the simplified and

  15. The Geostationary Fourier Transform Spectrometer

    Science.gov (United States)

    Key, Richard; Sander, Stanley; Eldering, Annmarie; Blavier, Jean-Francois; Bekker, Dmitriy; Manatt, Ken; Rider, David; Wu, Yen-Hung

    2012-01-01

    The Geostationary Fourier Transform Spectrometer (GeoFTS) is an imaging spectrometer designed for a geostationary orbit (GEO) earth science mission to measure key atmospheric trace gases and process tracers related to climate change and human activity. GEO allows GeoFTS to continuously stare at a region of the earth for frequent sampling to capture the variability of biogenic fluxes and anthropogenic emissions from city to continental spatial scales and temporal scales from diurnal, synoptic, seasonal to interannual. The measurement strategy provides a process based understanding of the carbon cycle from contiguous maps of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and chlorophyll fluorescence (CF) collected many times per day at high spatial resolution (2.7kmx2.7km at nadir). The CO2/CH4/CO/CF measurement suite in the near infrared spectral region provides the information needed to disentangle natural and anthropogenic contributions to atmospheric carbon concentrations and to minimize uncertainties in the flow of carbon between the atmosphere and surface. The half meter cube size GeoFTS instrument is based on a Michelson interferometer design that uses all high TRL components in a modular configuration to reduce complexity and cost. It is self-contained and as independent of the spacecraft as possible with simple spacecraft interfaces, making it ideal to be a "hosted" payload on a commercial communications satellite mission. The hosted payload approach for measuring the major carbon-containing gases in the atmosphere from the geostationary vantage point will affordably advance the scientific understating of carbon cycle processes and climate change.

  16. Retrieval of HCFC-142b (CH3CClF2) from ground-based high-resolution infrared solar spectra: Atmospheric increase since 1989 and comparison with surface and satellite measurements

    Science.gov (United States)

    Mahieu, Emmanuel; Lejeune, Bernard; Bovy, Benoît; Servais, Christian; Toon, Geoffrey C.; Bernath, Peter F.; Boone, Christopher D.; Walker, Kaley A.; Reimann, Stefan; Vollmer, Martin K.; O'Doherty, Simon

    2017-01-01

    We have developed an approach for retrieving HCFC-142b (CH3CClF2) from ground-based high-resolution infrared solar spectra, using its ν7 band Q branch in the 900-906 cm-1 interval. Interferences by HNO3, CO2 and H2O have to be accounted for. Application of this approach to observations recorded within the framework of long-term monitoring activities carried out at the northern mid-latitude, high-altitude Jungfraujoch station in Switzerland (46.5°N, 8.0°E, 3580 m above sea level) has provided a total column times series spanning the 1989 to mid-2015 time period. A fit to the HCFC-142b daily mean total column time series shows a statistically-significant long-term trend of (1.23±0.08×1013 molec cm-2) per year from 2000 to 2010, at the 2-σ confidence level. This corresponds to a significant atmospheric accumulation of (0.94±0.06) ppt (1 ppt=1/1012) per year for the mean tropospheric mixing ratio, at the 2-σ confidence level. Over the subsequent time period (2010-2014), we note a significant slowing down in the HCFC-142b buildup. Our ground-based FTIR (Fourier Transform Infrared) results are compared with relevant data sets derived from surface in situ measurements at the Mace Head and Jungfraujoch sites of the AGAGE (Advanced Global Atmospheric Gases Experiment) network and from occultation measurements by the ACE-FTS (Atmospheric Chemistry Experiment-Fourier Transform Spectrometer) instrument on-board the SCISAT satellite.

  17. Digital filter method of oversampling Fourier transform infrared spectrometer%过采样型傅里叶红外光谱仪的数字滤波方法

    Institute of Scientific and Technical Information of China (English)

    任利兵; 尉昊赟; 李岩

    2012-01-01

    The frequency response range of infrared detector in Fourier transform infrared spectrometer extends from dozens of Hz to some MHz generally. Because of wide frequency response, the measured signal will be easily blurred by lower and higher frequency noise from ambient. Noise can deform the real infrared interference signal. Compared with traditional Fourier transform infrared spectrometer, the oversampling one seems like to put the equal-spacing sampling procedure into computer. Therefore, it will be possible to lay a digital filter after the oversampling infrared interference signal. Based on evaluation of effective frequency response range of infrared interference signal, the design method of a Buttworth bandpass digital filter was illustrated. With this designed filter, the noise of oversampling infrared interference signal could be filtered. The experimental results show that the designed filter can effectively filter higher and lower noise to keep real spectral signal. Additionally, the digital filter is easier and more flexible to design than analog one.%傅里叶红外光谱仪使用的红外探测器频率响应范围通常为几十Hz到数MHz,这使得探测器直接接收的干涉信号中很容易混入环境噪声,引起真实干涉信号的畸变.过采样型傅里叶红外光谱仪等同于将传统光谱仪的等光程间隔采样过程“搬移”到计算机内,因此,理论上允许使用数字滤波器代替模拟滤波器对红外干涉信号降噪.在分析过采样型傅里叶红外光谱仪红外干涉信号有效频率范围的基础上,详述了适用于过采样型傅里叶红外光谱仪的巴特沃斯数字带通滤波器的设计方法,并应用设计的滤波器对过采样的红外干涉信号进行了降噪研究.结果表明:数字滤波的方法能有效去除红外干涉信号中的高、低频噪声,保留真实的光谱信号,在使用上也比模拟滤波更加灵活、便捷.

  18. Comparative Variable Temperature Studies of Polyamide II with a Benchtop Fourier Transform and a Miniature Handheld Near-Infrared Spectrometer Using 2D-COS and PCMW-2D Analysis.

    Science.gov (United States)

    Unger, Miriam; Pfeifer, Frank; Siesler, Heinz W

    2016-07-01

    The main objective of this communication is to compare the performance of a miniaturized handheld near-infrared (NIR) spectrometer with a benchtop Fourier transform near-infrared (FT-NIR) spectrometer. Generally, NIR spectroscopy is an extremely powerful analytical tool to study hydrogen-bonding changes of amide functionalities in solid and liquid materials and therefore variable temperature NIR measurements of polyamide II (PAII) have been selected as a case study. The information content of the measurement data has been further enhanced by exploiting the potential of two-dimensional correlation spectroscopy (2D-COS) and the perturbation correlation moving window two-dimensional (PCMW2D) evaluation technique. The data provide valuable insights not only into the changes of the hydrogen-bonding structure and the recrystallization of the hydrocarbon segments of the investigated PAII but also in their sequential order. Furthermore, it has been demonstrated that the 2D-COS and PCMW2D results derived from the spectra measured with the miniaturized NIR instrument are equivalent to the information extracted from the data obtained with the high-performance FT-NIR instrument.

  19. Optical Design of Spaceborne Shortwave Infrared Imaging Spectrometer with Wide Field of View%星载大视场短波红外成像光谱仪光学设计

    Institute of Scientific and Technical Information of China (English)

    薛庆生; 林冠宇; 宋克非

    2011-01-01

    Based on the requirements of shotwave infrared imaging spectrometer with wide field of view,considering the restrictive off-the-shelf detectors, a split field of view (FOV) method was developed. The principle of split field of view was analyzed. A spaceborne shortwave infrared imaging spectrometer with wide field of view was designed using the method. The imaging spectrometer are composed of a 11.42°telecentric off-axis three-mirror anastigmatic telescope and two offner convex grating spectral imaging system. Ray tracing, optimization and analyzing were performed by CODE V and ZEMAX software. The analyzed results demonstrate that the modulation transfer function for different spectral band is more than 0.7 which satisfies the pre-designed requirement.%根据大视场短波红外成像光谱仪的要求,考虑到市售探测器的限制,提出了视场分离的方法,分析了视场分离方法的原理.利用此方法设计了一个星载大视场短波红外成像光谱仪光学系统,该系统由11.42°远心离轴三反消像散前置望远系统和2个Offner凸面光栅光谱成像系统组成,运用光学设计软件CODE V和ZEMAX对成像光谱仪光学系统进行了光线追迹和优化,并对设计结果进行了分析,分析结果表明,光学系统在各个谱段的光学传递函数均达到0.7以上,完全满足设计指标要求.

  20. Investigation of Adaptive-threshold Approaches for Determining Area-Time Integrals from Satellite Infrared Data to Estimate Convective Rain Volumes

    Science.gov (United States)

    Smith, Paul L.; VonderHaar, Thomas H.

    1996-01-01

    The principal goal of this project is to establish relationships that would allow application of area-time integral (ATI) calculations based upon satellite data to estimate rainfall volumes. The research is being carried out as a collaborative effort between the two participating organizations, with the satellite data analysis to determine values for the ATIs being done primarily by the STC-METSAT scientists and the associated radar data analysis to determine the 'ground-truth' rainfall estimates being done primarily at the South Dakota School of Mines and Technology (SDSM&T). Synthesis of the two separate kinds of data and investigation of the resulting rainfall-versus-ATI relationships is then carried out jointly. The research has been pursued using two different approaches, which for convenience can be designated as the 'fixed-threshold approach' and the 'adaptive-threshold approach'. In the former, an attempt is made to determine a single temperature threshold in the satellite infrared data that would yield ATI values for identifiable cloud clusters which are closely related to the corresponding rainfall amounts as determined by radar. Work on the second, or 'adaptive-threshold', approach for determining the satellite ATI values has explored two avenues: (1) attempt involved choosing IR thresholds to match the satellite ATI values with ones separately calculated from the radar data on a case basis; and (2) an attempt involved a striaghtforward screening analysis to determine the (fixed) offset that would lead to the strongest correlation and lowest standard error of estimate in the relationship between the satellite ATI values and the corresponding rainfall volumes.

  1. Analysis of the sensitivity of thermal infrared nadir satellite observations to the chemical and micro-physical properties of upper tropospheric-lower stratospheric sulphate aerosols

    Science.gov (United States)

    Sellitto, Pasquale; Sèze, Geneviève; Legras, Bernard

    2015-04-01

    Secondary sulphate aerosols are the predominant typology of aerosols in the upper troposphere/lower stratosphere (UTLS), and can have an important impact on radiative transfer and climate, cirrus formation and chemistry in the UTLS. Despite their importance, the satellite observation at the regional scale of sulphate aerosols in the UTLS is limited. In this work, we address the sensitivity of the thermal infrared satellite observations to secondary sulphate aerosols in the UTLS. The absorption properties of sulphuric acid/water droplets, for different sulphuric acid mixing ratios and temperatures, are systematically analysed. The absorption coefficients are derived by means of a Mie code, using refractive indexes taken from the GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques : Management and Study of Spectroscopic Information) spectroscopic database and log-normal size distributions with different effective radii and number concentrations. IASI (Infrared Atmospheric Sounding Interferometer) and SEVIRI (Spinning Enhanced Visible and Infrared Imager) pseudo-observations are generated using forward radiative transfer calculations performed with the 4A (Automatized Atmospheric Absorption Atlas) radiative transfer model, to estimate the impact of the absorption of idealized aerosol layers, at typical UTLS conditions, on the radiance spectra observed by these simulated satellite instruments. We found a marked spectral signature of these aerosol layers between 700 and 1200 cm-1, due to the absorption bands of the sulphate and bi-sulphate ions and the undissociated sulphuric acid, with absorption peaks at 1170 and 905 cm-1. Micro-windows with a sensitivity to chemical and micro-physical properties of the sulphate aerosol layer are identified, and the role of interfering species, and temperature and water vapour profile is discussed.

  2. Uncooled near- and mid-IR spectrometer engine. Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Agiltron proposes to develop an extremely compact and high sensitivity uncooled near- and mid-infrared (NMIR) spectrometer engine for planetary compositional...

  3. Monitoring agricultural crop growth: comparison of high spatial-temporal satellite imagery versus UAV-based imaging spectrometer time series measurements

    Science.gov (United States)

    Mucher, Sander; Roerink, Gerbert; Franke, Jappe; Suomalainen, Juha; Kooistra, Lammert

    2014-05-01

    In 2012, the Dutch National Satellite Data Portal (NSD) was launched as a preparation to the launch of the European SENTINEL satellites in the framework of the Copernicus Programme. At the same time the Unmanned Aerial Remote Sensing Facility (UARSF: www.wageningenUR.nl/uarsf) has been established as research facility at Wageningen University and Research Centre. The NSD became available for the development of services and advice through an investment from the Dutch government in collaboration with the Netherlands Space Office (NSO) in order to develop new services for precision agriculture. The NSD contains Formosat, Radarsat as well as DMC satellite imagery. The processing of the DMC imagery resulted in the Greenmonitor service (www.groenmonitor.nl). The Greenmonitor is an unique product that covers the Netherlands with a high spatial and temporal resolution. The Greenmonitor is now being exploited for various applications, amongst others crop identification, crop phenology, and identification of management activities. The UARSF of Wageningen UR has three objectives: 1) to develop innovation in the field of remote sensing science using Unmanned Aerial Vehicles (UAV) by providing a platform for dedicated and high-quality experiments; 2) to support high quality UAV services by providing calibration facilities and disseminating processing procedures to the UAV user community; 3) to promote and test the use of UAV in a broad range of application fields such as precision agriculture and habitat monitoring. Through this coincidence of new developments the goal of our study was to compare the information for the measurements of spatial variation in crops and soils as derived from high spatial-temporal satellite imagery from the national data portal compared to the exploitation of UAVs, in our case an Altura octocopter with a hyperspectral camera. As such, the focus is on the applications in precision agriculture. Both primary producers and chain partners and service

  4. Synopsis of current satellite snow mapping techniques, with emphasis on the application of near-infrared data

    Science.gov (United States)

    Barnes, J. C.; Smallwood, M. D.

    1975-01-01

    The Skylab EREP S192 Multispectral Scanner data have provided for the first time an opportunity to examine the reflectance characteristics of snowcover in several spectral bands extending from the visible into the near-infrared spectral region. The analysis of the S192 imagery and digital tape data indicates a sharp drop in reflectance of snow in the near-infrared, with snow becoming essentially nonreflective in Bands 11 (1.55-1.75 micron) and 12 (2.10-2.35 micron). Two potential applications to snow mapping of measurements in the near-infrared spectral region are possible: (1) the use of a near-infrared band in conjunction with a visible band to distinguish automatically between snow and water droplet clouds; and (2) the use of one or more near-infrared bands to detect areas of melting snow.

  5. Spectrometer gun

    Science.gov (United States)

    Waechter, David A.; Wolf, Michael A.; Umbarger, C. John

    1985-01-01

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  6. Satellites of Xe transitions induced by infrared active vibrational modes of CF4 and C2F6 molecules.

    Science.gov (United States)

    Alekseev, Vadim A; Schwentner, Nikolaus

    2011-07-28

    Absorption and luminescence excitation spectra of Xe/CF(4) mixtures were studied in the vacuum UV region at high resolution using tunable synchrotron radiation. Pressure-broadened resonance bands and bands associated with dipole-forbidden states of the Xe atom due to collision-induced breakdown of the optical selection rules are reported. The spectra display in addition numerous satellite bands corresponding to transitions to vibrationally excited states of a Xe-CF(4) collisional complex. These satellites are located at energies of Xe atom transition increased by one quantum energy in the IR active v(3) vibrational mode of CF(4) (v(3) = 1281 cm(-1)). Satellites of both resonance and dipole-forbidden transitions were observed. Satellites of low lying resonance states are spectrally broad bands closely resembling in shape their parent pressure-broadened resonance bands. In contrast, satellites of dipole-forbidden states and of high lying resonance states are spectrally narrow bands (FWHM ∼10 cm(-1)). The satellites of dipole-forbidden states are orders of magnitude stronger than transitions to their parent states due to collision-induced breakdown of the optical selection rules. These satellites are attributed to a coupling of dipole-forbidden and resonance states induced by the electric field of the transient CF(4) (v(3) = 0 ↔ v(3) = 1) dipole. Similar satellites are present in spectra of Xe/C(2)F(6) mixtures where these bands are induced by the IR active v(10) mode of C(2)F(6). Transitions to vibrationally excited states of Xe-CF(4)(C(2)F(6)) collision pairs were also observed in two-photon LIF spectra.

  7. Development of a tunable Fabry-Perot etalon-based near-infrared interference spectrometer for measurement of the HeI 2{sup 3}S-2{sup 3}P spectral line shape in magnetically confined torus plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ogane, S.; Shikama, T., E-mail: shikama@me.kyoto-u.ac.jp; Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 615-8540 (Japan); Zushi, H. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580 (Japan)

    2015-10-15

    In magnetically confined torus plasmas, the local emission intensity, temperature, and flow velocity of atoms in the inboard and outboard scrape-off layers can be separately measured by a passive emission spectroscopy assisted by observation of the Zeeman splitting in their spectral line shape. To utilize this technique, a near-infrared interference spectrometer optimized for the observation of the helium 2{sup 3}S–2{sup 3}P transition spectral line (wavelength 1083 nm) has been developed. The applicability of the technique to actual torus devices is elucidated by calculating the spectral line shapes expected to be observed in LHD and QUEST (Q-shu University Experiment with Steady State Spherical Tokamak). In addition, the Zeeman effect on the spectral line shape is measured using a glow-discharge tube installed in a superconducting magnet.

  8. Investigation on the monthly variation of cirrus optical properties over the Indian subcontinent using cloud-aerosol lidar and infrared pathfinder satellite observation (Calipso)

    Science.gov (United States)

    Dhaman, Reji K.; Satyanarayana, Malladi; Jayeshlal, G. S.; Mahadevan Pillai, V. P.; Krishnakumar, V.

    2016-05-01

    Cirrus clouds have been identified as one of the atmospheric component which influence the radiative processes in the atmosphere and plays a key role in the Earth Radiation Budget. CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) is a joint NASA-CNES satellite mission designed to provide insight in understanding of the role of aerosols and clouds in the climate system. This paper reports the study on the variation of cirrus cloud optical properties of over the Indian sub - continent for a period of two years from January 2009 to December 2010, using cloud-aerosol lidar and infrared pathfinder satellite observations (Calipso). Indian Ocean and Indian continent is one of the regions where cirrus occurrence is maximum particularly during the monsoon periods. It is found that during the south-west monsoon periods there is a large cirrus cloud distribution over the southern Indian land masses. Also it is observed that the north-east monsoon periods had optical thick clouds hugging the coast line. The summer had large cloud formation in the Arabian Sea. It is also found that the land masses near to the sea had large cirrus presence. These cirrus clouds were of high altitude and optical depth. The dependence of cirrus cloud properties on cirrus cloud mid-cloud temperature and geometrical thickness are generally similar to the results derived from the ground-based lidar. However, the difference in macrophysical parameter variability shows the limits of space-borne-lidar and dissimilarities in regional climate variability and the nature and source of cloud nuclei in different geographical regions.

  9. A Satellite Time Slots Climatology of the Urban Heat Island of Guadalajara Megacity in Mexico from NOAA ¡/AVHRR THERMAL Infrared Monitoring (TIR)

    Science.gov (United States)

    Galindo, I.

    2009-04-01

    The urban heat island (UHI) of the metropolitan area of the second megacity of Mexico, named Guadalajara in Mexico is studied using thermal infrared data (TIR) (10 £ l £ 12 mm) obtained from the Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA polar orbitters whose signals are received on real time at our ground station for the period 1996-2006. The TIR data are selected by means of a software, since they depend on natural causes (e.g., atmospheric transparency, surface temperature, spectral emissivity and topography) and observational (time and incidence angle of the satellite pass, season of the year, etc.). The above conditions have a variable contribution to the measurements which it can be so high that they simulate the temporal-space fluctuations considered as thermal anomalies. Using a Geographic Information System and spatial analysis techniques temperatures are obtained for diofferent times of the day (satellite slots) and dropped into a grid with a 2.5 km distance between points (latitude, longitude). The temperatures obtained for each satellite pass slot (four per day) are monthly averaged and the temperature anomalies are represented in thermal isolines for the study area. The temperature difference usually is larger at night than during the day, reaching a thermal gradient of 9 °C.

  10. A Digital Micromirror Device-Based Hadamard Transform Near Infrared Spectrometer%基于数字微镜技术的阿达玛变换近红外光谱仪

    Institute of Scientific and Technical Information of China (English)

    刘佳; 陈奋飞; 廖乘胜; 许谦; 曾立波; 吴琼水

    2011-01-01

    构建了一个基于数字微镜技术的新型阿达玛变换近红外光谱仪.光学信号采用光纤引入,以光栅作为分光元件,利用数字微镜代替传统的机械式阿达玛模板进行光学编码调制,使用单点InGaAs红外探测器检测调制后的光信号,通过快速阿达玛解码还原出原始光谱.通过实验检验了光谱仪的分辨率、信噪比、稳定性以及谱图获取速度等指标.实验结果表明,所研制的光谱仪灵敏度高,信噪比高,响应速度快,体积小巧,其在油品检测、食品安全等行业有着广泛的应用前景.%A Hadamard transform near infrared spectrometer based on a digital micromirror device was constructed. The optical signal was collected by optical fiber, a grating was used for light diffraction, a digital micromirror device (DMD) was applied instead of traditional mechanical Hadamard masks for optical modulation, and an InGaAs near infrared detector was used as the optic sensor. The original spectrum was recovered by fast Hadamard transform algrithms. The advantages of the spectrometer, such as high resolution, signal-noise-ratio, stability, sensitivity and response speed were proved by experiments, which indicated that it is very suitable for oil and food-safety applications.

  11. Status of the OCS Bragg-Spectrometer for SODART

    DEFF Research Database (Denmark)

    Wiebicke, H.J.; Halm, I.; Christensen, Finn Erland;

    1998-01-01

    OCS, the Bragg spectrometer for the SODART X-ray telescope onboard the SPECTRUM-RONTGEN-GAMMA (SRG) satellite has been completed. Preliminary results of his performance are presented.......OCS, the Bragg spectrometer for the SODART X-ray telescope onboard the SPECTRUM-RONTGEN-GAMMA (SRG) satellite has been completed. Preliminary results of his performance are presented....

  12. The Spectrometer

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2012-01-01

    In the fall of 1999 I was shown an Ocean Optics spectrometer-in-the-computer at St. Patricks College at Maynooth, Ireland, and thought that I had seen heaven. Of course, it could not resolve the sodium D-lines (I had done that many years before with a homemade wire diffraction grating), and I began to realize that inside was some familiar old…

  13. On the joint use of IASI and GOSAT retrievals in the thermal infrared

    Science.gov (United States)

    Bureau, J.; Payan, S.; Camy-Peyret, C.; Clerbaux, C.; Coheur, P.; Hurtmans, D.; Hadji-Lazaro, J.; Bauduin, S.; George, M.

    2012-12-01

    GOSAT (Greenhouse Gases Observing SATellite) is a satellite dedicated to the study of greenhouses gases. It carries an infrared Fourier transform spectrometer (Thermal And Near infrared Sensor for carbon Observation-Fourier Transform Spectrometer or TANSO-FTS), which acquires spectra in 4 bands, located in the Near-Infrared (NIR), ShortWave Infrared (SWIR) and Thermal Infrared (TIR). An imager (Cloud and Aerosol Imager or TANSO-CAI) enables to gain information on clouds and aerosols, and this information is used to improve the quality of CO2 and CH4 retrievals. IASI (Infrared Atmospheric Sounding Interferometer) designed by CNES for Eumetsat is carried by the MetOp-A satellite. It is used for operational meteorology and is also interesting for greenhouse gases as well as for atmospheric chemistry and climate. We looked for close spatial and temporal coincidences with six TCCON sites where high resolution FTIR measurements are performed routinely. Cloud-free and spatially homogeneous fields of view (IFOVs) were selected using CAI images. The TCCON retrieved VMR profiles have been used as reference and compared with those we retrieved from coincident measurements of GOSAT and IASI. We used the [1240;1320] cm-1 window for CH4, and the [980;1100] cm-1 window for O3 retrieval. Finally, we will highlight the potential to further improve the results using the synergy between measurements in the TIR and the SWIR spectral domains.

  14. The front-end electronics of the Spectrometer Telescope for Imaging X-Rays (STIX) on the ESA Solar Orbiter satellite

    Science.gov (United States)

    Grimm, O.; Bednarzik, M.; Commichau, V.; Graczyk, R.; Gröbelbauer, H. P.; Hurford, G.; Krucker, S.; Limousin, O.; Meuris, A.; Orleański, P.; Przepiórka, A.; Seweryn, K.; Skup, K.; Viertel, G.

    2012-12-01

    Solar Orbiter is an ESA mission to study the heliosphere in proximity to the Sun, scheduled for launch in January 2017. It carries a suite of ten instruments for comprehensive remote-sensing and in-situ measurements. The Spectrometer Telescope for Imaging X-Rays (STIX), one of the remote sensing instruments, images X-rays between 4 and 150keV using an Fourier technique. The angular resolution is 7 arcsec and the spectral resolution 1keV full-width-half-maximum at 6keV. X-ray detection uses pixelized Cadmium Telluride crystals provided by the Paul Scherrer Institute. The crystals are bonded to read-out hybrids developed by CEA Saclay, called Caliste-SO, incorporating a low-noise, low-power analog front-end ASIC IDeF-X HD. The crystals are cooled to -20°C to obtain very low leakage currents of less than 60pA per pixel, the prerequisite for obtaining the required spectral resolution. This article briefly describes the mission goals and then details the front-end electronics design and main challenges, resulting in part from the allocation limit in mass of 7kg and in power of 4W. Emphasis is placed on the design influence of the cooling requirement within the warm environment of a mission approaching the Sun to within the orbit of Mercury. The design for the long-term in-flight energy calibration is also explained.

  15. The GRAVITY spectrometers: optical qualification

    Science.gov (United States)

    Yazici, Senol; Straubmeier, Christian; Wiest, Michael; Wank, Imke; Fischer, Sebastian; Horrobin, Matthew; Eisenhauer, Frank; Perrin, Guy; Perraut, Karine; Brandner, Wolfgang; Amorim, Antonio; Schöller, Markus; Eckart, Andreas

    2014-07-01

    GRAVITY1 is a 2nd generation Very Large Telescope Interferometer (VLTI) operated in the astronomical K-band. In the Beam Combiner Instrument2 (BCI) four Fiber Couplers3 (FC) will feed the light coming from each telescope into two fibers, a reference channel for the fringe tracking spectrometer4 (FT) and a science channel for the science spectrometer4 (SC). The differential Optical Path Difference (dOPD) between the two channels will be corrected using a novel metrology concept.5 The metrology laser will keep control of the dOPD of the two channels. It is injected into the spectrometers and detected at the telescope level. Piezo-actuated fiber stretchers correct the dOPD accordingly. Fiber-fed Integrated Optics6 (IO) combine coherently the light of all six baselines and feed both spectrometers. Assisted by Infrared Wavefront Sensors7 (IWS) at each Unit Telescope (UT) and correcting the path difference between the channels with an accuracy of up to 5 nm, GRAVITY will push the limits of astrometrical accuracy to the order of 10 μas and provide phase-referenced interferometric imaging with a resolution of 4 mas. The University of Cologne developed, constructed and tested both spectrometers of the camera system. Both units are designed for the near infrared (1.95 - 2.45 μm) and are operated in a cryogenic environment. The Fringe Tracker is optimized for highest transmission with fixed spectral resolution (R = 22) realized by a double-prism.8 The Science spectrometer is more diverse and allows to choose from three different spectral resolutions8 (R = [22, 500, 4000]), where the lowest resolution is achieved with a prism and the higher resolutions are realized with grisms. A Wollaston prism in each spectrometer allows for polarimetric splitting of the light. The goal for the spectrometers is to concentrate at least 90% of the ux in 2 × 2 pixel (36 × 36 μm2) for the Science channel and in 1 pixel (24 × 24 μm) in the Fringe Tracking channel. In Section 1, we present

  16. IIP Tropospheric Infrared Mapping Spectrometers (TIMS) demonstration of CO retrieval, including multi-layer, from atmospheric data acquired simultaneously in the solar reflective region near 2.3 um and the thermal emissive region near 4.7 um

    Science.gov (United States)

    Mergenthaler, J. L.; Kumer, J.; Roche, A. E.; Rairden, R. L.; Blatherwick, R.; Hawat, T.; Desouza-Machado, S.; Hannon, S.; Chatfield, R. B.

    2008-12-01

    The NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) Tropospheric Infrared Mapping Spectrometers (TIMS) have been developed to demonstrate measurement capability, when deployed in space, for multi-layer retrieval of CO from spectral measurements acquired in the solar reflective (SR) region ~ 4281 to 4301 cm-1 and in the thermal InfraRed (TIR) region ~ 2110 to 2165 cm-1. We describe joint deployment at Denver University (DU) with co-investigators there of the TIMS, and of the DU colleagues FTS, to acquire simultaneous measurements of atmospheric spectra in the SR and the TIR. The FTS provided validation radiance data for the TIMS. The TIMS retrievals of CO, H2O and CH4 agreed well with validation vs these as retrieved from the DU data, AIRS retrieval, standard models and ECMWF. The TIMS CO retrievals included column retrieved from the just the SR data, column retrieved from just the TIR data, and a simple two-layer retrieval from the combined data sets. The data were acquired in an operational mode that mimicked the operations in a conceptual application that would provide footprints, coverage, refresh time as in the Decadal Survey GEO-CAPE mission statement. Very encouraging CO precisions were achieved, e.g., the TIMS CO column retrieval from the SR data demonstrated better than the 10% precision requirement as listed on slide 32 of the GEO-CAPE Reference document http://geo- cape.larc.nasa.gov/docs/GEOMAC_FinalReport_no_costs.ppt

  17. Galileo Ultraviolet Spectrometer experiment

    Science.gov (United States)

    Hord, C. W.; Mcclintock, W. E.; Stewart, A. I. F.; Barth, C. A.; Esposito, L. W.; Thomas, G. E.; Sandel, B. R.; Hunten, D. M.; Broadfoot, A. L.; Shemansky, D. E.

    1992-01-01

    The Galileo ultraviolet spectrometer experiment uses data obtained by the Ultraviolet Spectrometer (UVS) mounted on the pointed orbiter scan platform and from the Extreme Ultraviolet Spectrometer (EUVS) mounted on the spinning part of the orbiter with the field of view perpendicular to the spin axis. The UVS is a Ebert-Fastie design that covers the range 113-432 nm with a wavelength resolution of 0.7 nm below 190 and 1.3 nm at longer wavelengths. The UVS spatial resolution is 0.4 deg x 0.1 deg for illuminated disk observations and 1 deg x 0.1 deg for limb geometries. The EUVS is a Voyager design objective grating spectrometer, modified to cover the wavelength range from 54 to 128 nm with wavelength resolution 3.5 nm for extended sources and 1.5 nm for point sources and spatial resolution of 0.87 deg x 0.17 deg. The EUVS instrument will follow up on the many Voyager UVS discoveries, particularly the sulfur and oxygen ion emissions in the Io torus and molecular and atomic hydrogen auroral and airglow emissions from Jupiter. The UVS will obtain spectra of emission, absorption, and scattering features in the unexplored, by spacecraft, 170-432 nm wavelength region. The UVS and EUVS instruments will provide a powerful instrument complement to investigate volatile escape and surface composition of the Galilean satellites, the Io plasma torus, micro- and macro-properties of the Jupiter clouds, and the composition structure and evolution of the Jupiter upper atmosphere.

  18. IR spectrometer project for the BTA telescope

    Science.gov (United States)

    Afanasiev, V. L.; Emelianov, E. V.; Murzin, V. A.; Vdovin, V. F.

    2013-07-01

    We introduce a project of new cooled infrared spectrometer-photometer for 6-m telescope BTA (Special Astrophysical Observatory of Russian Science Academy). The device would extend the wavelength range accessible for observations on the 6-m BTA telescope toward near infrared (0.8-2.5 um).

  19. IR Spectrometer Project for the BTA Telescope

    OpenAIRE

    Afanasiev, V. L.; Emelianov, E. V.; Murzin, V. A.; Vdovin, V. F.

    2013-01-01

    We introduce a project of new cooled infrared spectrometer-photometer for 6-m telescope BTA (Special Astrophysical Observatory of Russian Science Academy). The device would extend the wavelength range accessible for observations on the 6-m BTA telescope toward near infrared (0.8-2.5 um).

  20. MASS SPECTROMETER

    Science.gov (United States)

    White, F.A.

    1960-08-23

    A mass spectrometer is designed with a first adjustable magnetic field for resolving an ion beam into beams of selected masses, a second adjustable magnetic field for further resolving the ion beam from the first field into beams of selected masses, a thin foil disposed in the path of the beam between the first and second magnets to dissociate molecular ions incident thereon, an electrostatic field for further resolving the ion beam from the second field into beams of selected masses, and a detector disposed adjacent to the electrostatic field to receive the ion beam.

  1. Characteristics of total column ozone and nitrogen dioxide amount over Korea during the 2015 MAPS campaign: Pandora spectrometer, satellite and in-situ measurement

    Science.gov (United States)

    Go, S.; Chong, H. S.; Kim, W.; Kim, J.; Lee, H.; Kim, J. H.; KIM, J.; Herman, J. R.; Abuhassan, N.; Park, J. H.

    2015-12-01

    To improve the performances of satellite retrieval of surface pollution and air quality models, NIER (National Institute of Environmental Research) and NASA are planning the KORUS-AQ campaign over the Korean Peninsula in May-June, 2016. As a pre-campaign of the KORUS-AQ, MAPS (Megacity Air Pollution Studies)-Seoul was conducted from May to July, 2015. During this campaign, six Pandora instruments continuously provided total column density of O3 and NO2 over Korea. These measurements will be continued until the end of 2016 covering the KORUS-AQ campaign period and beyond for the initial validation of TROPOMI measurements. To assess the variation of O3 and NO2, data were collected from Pandora, Dobson spectrophotometer, Brewer spectrophotometer, other ground-based in situ measurements and Ozone Monitoring Instrument (OMI). Ozone column density from Pandora exhibited significantly high correlation (R2 > 0.8) with the ground-based Dobson and Brewer spectrophotometers. Due to the detector anomaly and wide spatial pixel coverage, O3 values from OMI showed lower correlation (R2 > 0.6) with the Pandora. Even though six Pandoras were scattered across the country, O3 data showed similar distribution, in accordance with the low spatial variability of ozone. On the contrary, NO2 distribution pattern showed large difference at each site, which showed peak at around 10 a.m., with larger diurnal variability in urban area than that in rural area by more than 5 times. As most of Pandora sites do not have on-site in situ NO2 measurements, other in situ data from the nearest Air Korea stations were used for the comparison. The comparison result showed significant correlation, although, the correlation coefficient was relatively lower than that of O3. Pandora measurements agreed well with the ground based instruments and OMI satellite data with averaged residuals less than 2% in O3. In case of NO2 Pandora measurements showed similar trend with in situ measurements.

  2. High resolution solar soft X-ray spectrometer

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fei; WANG Huan-Yu; PENG Wen-Xi; LIANG Xiao-Hua; ZHANG Chun-Lei; CAO Xue-Lei; JIANG Wei-Chun; ZHANG Jia-Yu; CUI Xing-Zhu

    2012-01-01

    A high resolution solar soft X-ray spectrometer (SOX) payload onboard a satellite is developed.A silicon drift detector (SDD) is adopted as the detector of the SOX spectrometer.The spectrometer consists of the detectors and their readout electronics,a data acquisition unit and a payload data handling unit.A ground test system is also developed to test SOX.The test results show that the design goals of the spectrometer system have been achieved.

  3. Temperature dependent ozone absorption cross section spectra measured with the GOME-2 FM3 spectrometer and first application in satellite retrievals

    Directory of Open Access Journals (Sweden)

    W. Chehade

    2012-10-01

    Full Text Available The Global Ozone Monitoring Experiment (GOME-2 Flight Model (FM absorption cross section spectra of ozone were measured under representative atmospheric conditions in the laboratory setup at temperatures between 203 K and 293 K in the wavelength range of 230–790 nm at a medium spectral resolution of 0.24 to 0.54 nm. Since the exact ozone amounts were unknown in the gas flow system used, the measured ozone cross sections were required to be scaled to absolute cross section units using published literature data. The Hartley, Huggins and Chappuis bands were recorded simultaneously and their temperature dependence is in good agreement with previous studies (strong temperature effect in the Huggins band and weak in the Hartley and Chappuis bands. The overall agreement of the GOME-2 FM cross sections with the literature data is well within 3%. The total ozone column retrieved from the GOME-2/MetOp-A satellite using the new cross section data is within 1% compared to the ozone amounts retrieved routinely from GOME-2.

  4. Theoretical model atmosphere spectra used for the calibration of infrared instruments

    CERN Document Server

    Decin, L

    2007-01-01

    One of the key ingredients in establishing the relation between input signal and output flux from a spectrometer is accurate determination of the spectrophotometric calibration. In the case of spectrometers onboard satellites, the accuracy of this part of the calibration pedigree is ultimately linked to the accuracy of the set of reference SEDs that the spectrophotometric calibration is built on. In this paper, we deal with the spectrophotometric calibration of infrared (IR) spectrometers onboard satellites in the 2 to 200 micron range. We aim at comparing the different reference SEDs used for the IR spectrophotometric calibration. The emphasis is on the reference SEDs of stellar standards with spectral type later than A0, with special focus on the theoretical model atmosphere spectra. Using the MARCS model atmosphere code, spectral reference SEDs were constructed for a set of IR stellar standards (A dwarfs, solar analogs, G9-M0 giants). A detailed error analysis was performed to estimate proper uncertainties...

  5. Comparability of red/near-infrared reflectance and NDVI based on the spectral response function between MODIS and 30 other satellite sensors using rice canopy spectra.

    Science.gov (United States)

    Huang, Weijiao; Huang, Jingfeng; Wang, Xiuzhen; Wang, Fumin; Shi, Jingjing

    2013-11-26

    Long-term monitoring of regional and global environment changes often depends on the combined use of multi-source sensor data. The most widely used vegetation index is the normalized difference vegetation index (NDVI), which is a function of the red and near-infrared (NIR) spectral bands. The reflectance and NDVI data sets derived from different satellite sensor systems will not be directly comparable due to different spectral response functions (SRF), which has been recognized as one of the most important sources of uncertainty in the multi-sensor data analysis. This study quantified the influence of SRFs on the red and NIR reflectances and NDVI derived from 31 Earth observation satellite sensors. For this purpose, spectroradiometric measurements were performed for paddy rice grown under varied nitrogen levels and at different growth stages. The rice canopy reflectances were convoluted with the spectral response functions of various satellite instruments to simulate sensor-specific reflectances in the red and NIR channels. NDVI values were then calculated using the simulated red and NIR reflectances. The results showed that as compared to the Terra MODIS, the mean relative percentage difference (RPD) ranged from -12.67% to 36.30% for the red reflectance, -8.52% to -0.23% for the NIR reflectance, and -9.32% to 3.10% for the NDVI. The mean absolute percentage difference (APD) compared to the Terra MODIS ranged from 1.28% to 36.30% for the red reflectance, 0.84% to 8.71% for the NIR reflectance, and 0.59% to 9.32% for the NDVI. The lowest APD between MODIS and the other 30 satellite sensors was observed for Landsat5 TM for the red reflectance, CBERS02B CCD for the NIR reflectance and Landsat4 TM for the NDVI. In addition, the largest APD between MODIS and the other 30 satellite sensors was observed for IKONOS for the red reflectance, AVHRR1 onboard NOAA8 for the NIR reflectance and IKONOS for the NDVI. The results also indicated that AVHRRs onboard NOAA7-17 showed

  6. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Nuristan mineral district in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.; Arko, Scott A.; Harbin, Michelle L.; Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Nuristan mineral district, which has gem, lithium, and cesium deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2008,2009), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS

  7. Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This DS consists of the locally enhanced ALOS image mosaics for each of the 24 mineral project areas (referred to herein as areas of interest), whose locality names, locations, and main mineral occurrences are shown on the index map of Afghanistan (fig. 1). ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency, but the image processing has altered the original pixel structure and all image values of the JAXA

  8. Hydrocarbons on the Icy Satellites of Saturn

    Science.gov (United States)

    Cruikshank, Dale P.

    2010-01-01

    The Visible-Infrared Mapping Spectrometer on the Cassini Spacecraft has obtained spectral reflectance maps of the satellites of Saturn in the wavelength region 0.4-5.1 micrometers since its insertion into Saturn orbit in late 2004. We have detected the spectral signature of the C-H stretching molecular mode of aromatic and aliphatic hydrocarbons in the low albedo material covering parts of several of Saturn's satellites, notably Iapetus and Phoebe (Cruikshank et al. 2008). The distribution of this material is complex, and in the case of Iapetus we are seeking to determine if it is related to the native grey-colored materials left as lag deposits upon evaporation of the ices, or represents in-fall from an external source, notably the newly discovered large dust ring originating at Phoebe. This report covers our latest exploration of the nature and source of this organic material.

  9. In-situ Iberian pig carcass classification using a micro-electro-mechanical system (MEMS)-based near infrared (NIR) spectrometer.

    Science.gov (United States)

    Zamora-Rojas, E; Pérez-Marín, D; De Pedro-Sanz, E; Guerrero-Ginel, J E; Garrido-Varo, A

    2012-03-01

    Iberian pig (IP) products are gourmet foods highly appreciated at international markets, reaching high prices, because of its exquisite flavors. At present, there aren't practical and affordable analytical methods which can authenticate every single piece put on the market. This paper reports on the performance of a handheld micro-electro-mechanical system (MEMS)-based spectrometer (1600-2400nm) for authentication-classification of individual IP carcasses into different commercial categories. Performance (accuracy and instrumental design) of the instrument was compared with that of high-resolution NIRS monochromators (400-2500nm). A total of 300 carcasses of IPs raised under different feeding regimes ("Acorn", "Recebo" and "Feed") were analyzed in three modes (intact fat in the carcass, skin-free subcutaneous fat samples and melted fat samples). The best classification results for the MEMS instrument were: 93.9% "Acorn" carcasses correctly classified, 96.4% "Feed" and 60.6% "Recebo", respectively. Evaluation of model performance confirmed the suitability of the handheld device for individual, fast, non-destructive, low-cost analysis of IP carcasses on the slaughterhouse line.

  10. Computer Spectrometers

    Science.gov (United States)

    Dattani, Nikesh S.

    2017-06-01

    Ideally, the cataloguing of spectroscopic linelists would not demand laborious and expensive experiments. Whatever an experiment might achieve, the same information would be attainable by running a calculation on a computer. Kolos and Wolniewicz were the first to demonstrate that calculations on a computer can outperform even the most sophisticated molecular spectroscopic experiments of the time, when their 1964 calculations of the dissociation energies of H_2 and D_{2} were found to be more than 1 cm^{-1} larger than the best experiments by Gerhard Herzberg, suggesting the experiment violated a strict variational principle. As explained in his Nobel Lecture, it took 5 more years for Herzberg to perform an experiment which caught up to the accuracy of the 1964 calculations. Today, numerical solutions to the Schrödinger equation, supplemented with relativistic and higher-order quantum electrodynamics (QED) corrections can provide ro-vibrational spectra for molecules that we strongly believe to be correct, even in the absence of experimental data. Why do we believe these calculated spectra are correct if we do not have experiments against which to test them? All evidence seen so far suggests that corrections due to gravity or other forces are not needed for a computer simulated QED spectrum of ro-vibrational energy transitions to be correct at the precision of typical spectrometers. Therefore a computer-generated spectrum can be considered to be as good as one coming from a more conventional spectrometer, and this has been shown to be true not just for the H_2 energies back in 1964, but now also for several other molecules. So are we at the stage where we can launch an array of calculations, each with just the atomic number changed in the input file, to reproduce the NIST energy level databases? Not quite. But I will show that for the 6e^- molecule Li_2, we have reproduced the vibrational spacings to within 0.001 cm^{-1} of the experimental spectrum, and I will

  11. Frequency based detection and monitoring of small scale explosive activity by comparing satellite and ground based infrared observations at Stromboli Volcano, Italy

    Science.gov (United States)

    Worden, Anna; Dehn, Jonathan; Ripepe, Maurizio; Donne, Dario Delle

    2014-08-01

    Thermal activity is a common precursor to explosive volcanic activity. The ability to use these thermal precursors to monitor the volcano and obtain early warning about upcoming activity is beneficial for both human safety and infrastructure security. By using a very reliably active volcano, Stromboli Volcano in Italy, a method has been developed and tested to look at changes in the frequency of small scale explosive activity and how this activity changes prior to larger, ash producing explosive events. Thermal camera footage was used to designate parameters for typical explosions at Stromboli (size of spatter field, cooling rate, frequency of explosions) and this information was applied to characterize explosions in satellite imagery. Satellite data from The National Aeronautics and Space Administration's Moderate Resolution Imaging Spectroradiometer (MODIS) and US/Japan designed Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) for numerous periods in 2002 to 2009 were analyzed for thermal features which were used to calculate an estimate of the level of activity during the given time period. The results at Stromboli showed a high level of small scale explosions which stop completely prior to large paroxysmal eruptive episodes. This activity also corresponds well to seismic and infrasonic records at Stromboli, indicating that this thermal infrared monitoring method may be used in conjunction with other detection methods where available, and also indicates that it may be a useful method for volcano monitoring when other methods (e.g. seismic instrumentation, infrasound arrays, etc.) are not available.

  12. Dual waveband compact catadioptric imaging spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Chrisp, Michael P.

    2012-12-25

    A catadioptric dual waveband imaging spectrometer that covers the visible through short-wave infrared, and the midwave infrared spectral regions, dispersing the visible through shortwave infrared with a zinc selenide grating and midwave infrared with a sapphire prism. The grating and prism are at the cold stop position, enabling the pupil to be split between them. The spectra for both wavebands are focused onto the relevant sections of a single dual waveband detector. Spatial keystone distortion is controlled to less than one tenth of a pixel over the full wavelength range, facilitating the matching of the spectra in the midwave infrared with the shorter wavelength region.

  13. [Current status and prospects of portable NIR spectrometer].

    Science.gov (United States)

    Yu, Xin-Yang; Lu, Qi-Peng; Gao, Hong-Zhi; Peng, Zhong-Qi

    2013-11-01

    Near-infrared spectroscopy (NIRS) is a reliable, rapid, and non-destructive analytical method widely applied in as a number of fields such as agriculture, food, chemical and oil industry. In order to suit different applications, near-infrared spectrometers are now varied. Portable near-infrared spectrometers are needed for rapid on-site identification and analysis. Instruments of this kind are rugged, compact and easy to be transported. In this paper, the current states of portable near-infrared spectrometers are reviewed. Portable near-infrared spectrometers are built of different monochromator systems: filter, grating, Fourier-transform methods, acousto-optic tunable filter (AOTF) and a large number of new methods based on micro-electro-mechanical systems (MEMS). The first part focuses on working principles of different monochromator systems. Advantages and disadvantages of different systems are also briefly mentioned. Descriptions of each method are given in turn. Typical spectrometers of each kind are introduced, and some parameters of these instruments are listed. In the next part we discuss sampling adapters, display, power supply and some other parts, which are designed to make the spectrometer more portable and easier to use. In the end, the current states of portable near-infrared spectrometers are summarized. Future trends of development of portable near-infrared spectrometers in China and abroad are discussed.

  14. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Ahankashan mineral district in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Ahankashan mineral district, which has copper and gold deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2007,2008, 2009, 2010),but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this

  15. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the South Bamyan mineral district in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the South Bamyan mineral district, which has areas with a spectral reflectance anomaly that require field investigation. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2006,2007, 2008),but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that

  16. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the North Bamyan mineral district in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the North Bamyan mineral district, which has copper deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2006,2007, 2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such

  17. Polar-Orbiting Satellite (POES) Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from camera systems or radiometer instruments on satellites in orbit around the poles. Satellite campaigns include...

  18. Defense Meteorological Satellite Program (DMSP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Defense Meteorological Satellite Program (DMSP) satellites collect visible and infrared cloud imagery as well as monitoring the atmospheric, oceanographic,...

  19. Sensitive measurements of trace gas of formaldehyde using a mid-infrared laser spectrometer with a compact multi-pass cell

    Science.gov (United States)

    Tanaka, Kotaro; Miyamura, Kai; Akishima, Kazushi; Tonokura, Kenichi; Konno, Mitsuru

    2016-11-01

    A compact multi-pass cell with a pair of cylindrical mirrors for sensitive detection of trace gases in emission from combustion was constructed. The cell path-length was 9.8 m and its volume was 0.13 L. Each mirror shape was a square with a side length of 25.4 mm and the mirrors were placed 100 mm apart. The cell was applied to detection of formaldehyde (HCHO), which is formed during fuel combustion and is harmful to the environment. The direct absorption spectrum in the range 2979.06-2981.2 cm-1 was recorded with a mid-infrared distributed feedback (DFB) interband cascade laser. The recorded spectrum of HCHO was in good agreement with a spectrum simulated using the HITRAN 2012 database. An absorption line at 2979.663 cm-1 (4.26 × 10-21 cm2 molecule-1 cm-1, ν5, 1184-1073), which showed the strongest absorption in the emission frequency range of the DFB interband cascade laser, was selected for HCHO detection. We also confirmed that there were no interferences of absorption peaks of major combustion products in the selected HCHO absorption peaks. At a signal-to-noise ratio of two and 3 kPa using 2f wavelength modulation spectroscopy at less than 1 MHz bandwidth, the limit of detection for HCHO was 73 ppb by volume.

  20. Performance characteristics of a passively locked cavity-enhanced absorption spectrometer with wideband-tunable multimode near-infrared light source

    Science.gov (United States)

    Someya, Ryuta; Imamura, Takeshi; Okamoto, Tetsushi; Hatano, Hiroshi; Toyoshima, Naoko; Tei, Kazuyoku; Yamaguchi, Shigeru

    2016-03-01

    A trace material detection system was developed on the basis of cavity-enhanced absorption spectroscopy (CEAS) using a fiber-coupled passively locked external cavity diode laser (PLEC-DL) in the near-infrared (NIR) wavelength region. The oscillation range of an antireflection-coated diode laser (AR-DL) coupled into an external cavity could be simply selected with a narrowband bandpass filter (1 nm), resulting in a stable wavelength oscillation in the wideband tunability between 1640 and 1680 nm. The external cavity acts as a trace material sensor that exhibits excellent flexibility because it is free from the DL source and is carefully designed with mirrors having reflectivities of ca. 99.995 and 99.99%. Trace-level detection was successfully demonstrated with the developed sensor having a minimum detectable absorption coefficient of 2.4 × 10-8 cm-1, which corresponds to 0.15 ppm for CH4 concentration without interference from H2O absorption lines under atmospheric pressure.

  1. Biological Process Oriented Online Fourier Transform Infrared Spectrometer%面向生物过程的在线式傅里叶变换红外光谱仪

    Institute of Scientific and Technical Information of China (English)

    谢非; 吴琼水; 曾立波

    2015-01-01

    An online Fourier Transform Infrared Spectrometer and an ATR (Attenuated Total Reflection) probe ,specifically at the application of real time measurement of the reaction substrate concentration in biological processes ,were designed .(1) The spectrometer combined the theories of double cube‐corner reflectors and flat mirror ,which created a kind of high performance in‐terferometer system .The light path folding way was utilized to makes the interferometer compact structure .Adopting double cube‐corner reflectors ,greatly reduces the influence of factors in the process of moving mirror movement such as rotation ,tilt , etc .The parallelogram oscillation flexible support device was utilized to support the moving mirror moves .It cancelled the fric‐tion and vibration during mirror moving ,and ensures the smooth operation .The ZnSe splitter significantly improved the hard‐ware reliability in high moisture environment .The method of 60° entrance to light splitter improves the luminous flux .(2)An ATR in situ measuring probe with simple structure ,large‐flux ,economical and practical character was designed in this article . The transmission of incident light and the light output utilized the infrared pipe with large diameter and innerplanted‐high plating membrane ,which conducted for the infrared transmission media of ATR probe .It greatly reduced the energy loss of infrared light after multiple reflection on the inner wall of the light pipe .Therefore ,the ATR probe obtained high flux ,improved the sig‐nal strength ,which make the signal detected easily .Finally ,the high sensitivity of MCT (Mercury Cadmium Telluride) detector was utilized to realize infrared interference signal collection ,and improved the data quality of detection .The test results showed that the system yields the advantages of perfect moisture‐proof performance ,luminous flux ,online measurement ,etc .The de‐signed online Fourier infrared spectrometer can real‐time measured

  2. Ultra Compact Imaging Spectrometer (UCIS)

    Science.gov (United States)

    Blaney, Diana L.; Green, Robert; Mouroulis, Pantazis; Cable, Morgan; Ehlmann, Bethany; Haag, Justin; Lamborn, Andrew; McKinley, Ian; Rodriguez, Jose; van Gorp, Byron

    2016-10-01

    The Ultra Compact Imaging Spectrometer (UCIS) is a modular visible to short wavelength infrared imaging spectrometer architecture which could be adapted to a variety of mission concepts requiring low mass and low power. Imaging spectroscopy is an established technique to address complex questions of geologic evolution by mapping diagnostic absorption features due to minerals, organics, and volatiles throughout our solar system. At the core of UCIS is an Offner imaging spectrometer using M3 heritage and a miniature pulse tube cryo-cooler developed under the NASA Maturation of Instruments for Solar System Exploration (MatISSE) program to cool the focal plane array. The TRL 6 integrated spectrometer and cryo-cooler provide a basic imaging spectrometer capability that is used with a variety of fore optics to address lunar, mars, and small body science goals. Potential configurations include: remote sensing from small orbiters and flyby spacecraft; in situ panoramic imaging spectroscopy; and in situ micro-spectroscopy. A micro-spectroscopy front end is being developed using MatISSE funding with integration and testing planned this summer.

  3. Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This DS consists of the locally enhanced ALOS image mosaics for each of the 24 mineral project areas (referred to herein as areas of interest), whose locality names, locations, and main mineral occurrences are shown on the index map of Afghanistan (fig. 1). ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency, but the image processing has altered the original pixel structure and all image values of the JAXA

  4. SPECIES: a multi-channel infrared laser spectrometer with optical-feedback cavity-enhanced absorption for in-situ balloon-borne and airborne measurements

    Science.gov (United States)

    Jacquet, Patrick; Catoire, Valery; Chartier, Michel; Robert, Claude; Krysztofiak, Gisele; Huret, Nathalie; Romanini, Daniele

    2017-04-01

    Over the last decades, thanks to significant technological advances in measurement techniques, our understanding of the chemistry and dynamics of the upper troposphere and stratosphere has progressed significantly. However some key questions remain unsolved and new ones arise in the climate change context. The full recovery of the ozone layer in a period of halogens decrease and N2O increase (and the delay of this recovery), the impact of the climate change on the stratosphere and the role of this one as a feedback are very uncertain. To address these challenges, one needs instruments able to measure a wide variety of trace gases simultaneously with a wide vertical range, combined to chemical and dynamical modelling at different scales. LPC2E and LIPHY laboratories are developing a new balloon-borne and airborne instrument: SPECIES (SPECtromètre Infrarouge à lasErs in Situ). Based on the Optical Feedback Cavity Enhanced Spectroscopy (OF-CEAS) technique combined with mid-infrared quantum or interband cascade lasers (QCLs or ICLs), this instrument will offer unprecedented performances in terms of vertical extent of the measurements, from ground to the middle stratosphere, and number of molecular species simultaneously measured with sub-ppb detection limits (e.g. O3, N2O, HNO3, NH3, H2O2, HCl, HOCl,CF2O, CH4, CH2O, CO, CO2, OCS, SO2). Due to high frequency measurement (>0.5 Hz) it shall offer very high spatial resolution (a few meters).

  5. On-board Data Processing to Lower Bandwidth Requirements on an Infrared Astronomy Satellite: Case of Herschel-PACS Camera

    Directory of Open Access Journals (Sweden)

    Christian Reimers

    2005-09-01

    Full Text Available This paper presents a new data compression concept, “on-board processing,” for infrared astronomy, where space observatories have limited processing resources. The proposed approach has been developed and tested for the PACS camera from the European Space Agency (ESA mission, Herschel. Using lossy and lossless compression, the presented method offers high compression ratio with a minimal loss of potentially useful scientific data. It also provides higher signal-to-noise ratio than that for standard compression techniques. Furthermore, the proposed approach presents low algorithmic complexity such that it is implementable on the resource-limited hardware. The various modules of the data compression concept are discussed in detail.

  6. Characterizing Debris in the Infrared with UKIRT

    Science.gov (United States)

    Lederer, S. M.; Jah, M.; Kendrick, R.; Buckalew, B.; Frith, J. M.; Cowardin, H. M.; Bold, M.

    2015-01-01

    The United Kingdom Infrared Telescope (UKIRT) has been a major asset for the NASA Orbital Debris Program Office (OPDO) since March, 2014. With the UKIRT current contract coming to an end at the finish of FY15, there is a golden opportunity for this community to fund and gain access to UKIRT as an SSA asset through HCAR (Hawaii Center for Astronautics Research). UKIRT is the only telescope on Mauna Kea dedicated to infrared bands. Spectral coverage ranges from the near- (0.8-5µm) to the mid- to far-infrared (8-25 micrometer) regime. To date, debris observations have been collected with three instruments. Near-Infrared photometry with ZYJHK filters has been obtained with the Wide Field Camera (WFCam). Near-Infrared (1-2.5 micrometer) spectra are the focus of observations taken with the UKIRT Imager SpecTrometer (UIST). And Michelle (Mid Infrared escCHELLE) is a thermal imager-spectrometer designed for the 8-25 micrometer regime. With 35% of the telescope time allocated to ODPO, a very steady stream of data has been collected on a variety of debris targets using all the above instrumentation. Initial results from WFCam were discussed at AMOS and NISOI including analyses on IDCSPs, the MSG cooler and baffle covers. The cylindrical HS-376 buses were the focus of recent WFCam runs. Summary analyses of these works will be presented. Focus will be given to initial results of the data collected with the Cassegrain instruments, UIST and Michelle. UIST spectra were collected in September 2014, March and April 2015. Targets included a suite of HS-376 buses, well suited to investigate the signatures of blue solar panels; several dead satellites with solar array wings; Titan 3C transtage debris; the CTA Array cover, and others. In addition, Michelle mid-IR photometry was collected on a select few objects during the April 2015 run. Using WFCam, UIST and Michelle the Lockheed Martin has been observing operational satellites in the near- mid and far-infrared regime in an attempt

  7. 美军SBIRS GEO-1预警卫星探测预警能力分析%Analysis on infrared detecting and early warning capabilities of America's SBIRS GEO-1 satellite

    Institute of Scientific and Technical Information of China (English)

    李小将; 金山; 廖海玲; 王建华

    2013-01-01

    For effectively responding to the threats of ballistic missiles and protecting the US's national and allies' interests, the US army continually develops and consummates the space-based infrared early warning system. The paper introduces the status and development of US's space-based infrared system,explores the coverage characteristic of the first space-based infrared geosynchronous orbit satellite,builds the GEO-1 satellite's infrared detecting model and early warning model, analyzes the detecting and early warning efficiencies of SBIRS GEO-1 satellite.%为有效应对弹道导弹威胁,维护本土与盟国利益,美军不断发展完善其天基红外预警系统.介绍了美军天基红外系统的发展现状,分析了首颗天基红外系统静止轨道(SBIRS GEO-1)卫星的覆盖范围,建立了SBIRS GEO-1卫星的红外探测模型和弹道预警模型,对其在轨探测预警能力进行了初步仿真分析.

  8. Using Isotope Ratio Infrared Spectrometer to determine δ13C of CaCO3 carbonate and DIC samples and δ18O of water

    Science.gov (United States)

    Mandic, M.; Stöbener, N.; Mandic, L.; Smajgl, D.; Jost, H. J. H.

    2016-12-01

    Precise and accurate determination of isotopic composition of carbon (13C) and oxygen (18O) from carbonate or DIC sample with proper referencing and data evaluation algorithm presents a challenge for scientists. Mass spectrometry was the only widely used technique for this kind of analysis, but recent advances make laser based isotope ratio infrared spectroscopy (IRIS) a viable alternative. To analyze discrete samples, the Universal Reference Interface (URI) Connect was developed. CO2 free syntethic air is used to flush out the contents of a sample container into a variable volume. If necessary, the sample is further diluted before entering the analysis chamber. Reference gas measurements are automatically performed at the same concentration as sample measurements to compensate for instrument drifts and non linearity. The URI Connect can handle about 100 samples per day from an autosampler, or samples can be injected one at a time through a septum on the front of the instrument. Gas samples collected in flasks, bags, syringes, or vials can be analyzed. The system only needs the equivalent of about 80µg - or 40µL - of pure CO2 gas to complete an analysis. Due to it's small weight and robustness, sample analysis can be performed in the field, e.g. aboard a research vessel. To demonstrate the performance, a test experiment with 1% CO2 in 12 ml vials was performed. We achieved an internal precision of better than 0.07‰ and 0.1‰ for δ13C and δ18O, respectively. Analyses with sample amounts as low as 200 μg of carbonate can also be performed reliably with IRIS. We present measurements of three international reference materials, and one of them treated as an unknown. Five samples each of approximately 1mg each were acidified using a few droplets of 43% H3PO4 and left for equilibration overnight at 25°C. The standard deviation was less than 0.1‰ δ13C and the accuracy <0.01‰ As another example of head space analysis in 12 ml vials, we determined δ18O of

  9. MISTiC Winds, a Micro-Satellite Constellation Approach to High Resolution Observations of the Atmosphere using Infrared Sounding and 3D Winds Measurements

    Science.gov (United States)

    Maschhoff, K. R.; Polizotti, J. J.; Susskind, J.; Aumann, H. H.

    2015-12-01

    MISTiCTM Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sun-synchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's Atmospheric Infrared Sounder that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  10. Infrared Astronomy with Arrays: The Next Generation; Sunset Village, Los Angeles, CA, Oct. 1993

    Science.gov (United States)

    Mclean, Ian S.

    1994-01-01

    Conference papers on infrared array techniques and methods for infrared astronomy are presented. Topics covered include the following: infrared telescopes; infrared spectrometers; spaceborne astronomy; astronomical observatories; infrared cameras; imaging techniques; sky surveys; infrared photography; infrared photometry; infrared spectroscopy; equipment specifications; data processing and analysis; control systems; cryogenic equipment; adaptive optics; image resolution; infrared detector materials; and focal plane arrays.

  11. Near-infrared brightness of the Galilean satellites eclipsed in Jovian shadow: A new technique to investigate Jovian upper atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Tsumura, K. [Frontier Research Institute for Interdisciplinary Science, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Arimatsu, K.; Matsuura, S.; Shirahata, M.; Wada, T. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronoutical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 252-5210 (Japan); Egami, E. [Department of Astronomy, Arizona University, Tucson, AZ 85721 (United States); Hayano, Y.; Minowa, Y. [Hawaii Observatory, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Honda, C. [Research Center for Advanced Information Science and Technology, Aizu Research Cluster for Space Science, The University of Aizu, Aizu-Wakamatsu, Fukushima 965-8589 (Japan); Kimura, J. [Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Kuramoto, K.; Takahashi, Y. [Department of Cosmosciences, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Nakajima, K. [Department of Earth and Planetary Sciences, Kyushu University, Fukuoka 812-8581 (Japan); Nakamoto, T. [Department of Earth and Planetary Sciences, Graduate School of Science and Engineering, Tokyo Institute of Technology, Tokyo 152-8551 (Japan); Surace, J., E-mail: tsumura@astr.tohoku.ac.jp [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)

    2014-07-10

    Based on observations from the Hubble Space Telescope and the Subaru Telescope, we have discovered that Europa, Ganymede, and Callisto are bright around 1.5 μm even when not directly lit by sunlight. The observations were conducted with non-sidereal tracking on Jupiter outside of the field of view to reduce the stray light subtraction uncertainty due to the close proximity of Jupiter. Their eclipsed luminosity was 10{sup –6}-10{sup –7} of their uneclipsed brightness, which is low enough that this phenomenon has been undiscovered until now. In addition, Europa in eclipse was <1/10 of the others at 1.5 μm, a potential clue to the origin of the source of luminosity. Likewise, Ganymede observations were attempted at 3.6 μm by the Spitzer Space Telescope, but it was not detected, suggesting a significant wavelength dependence. It is still unknown why they are luminous even when in the Jovian shadow, but forward-scattered sunlight by hazes in the Jovian upper atmosphere is proposed as the most plausible candidate. If this is the case, observations of these Galilean satellites while eclipsed by the Jovian shadow provide us with a new technique to investigate the Jovian atmospheric composition. Investigating the transmission spectrum of Jupiter by this method is important for investigating the atmosphere of extrasolar giant planets by transit spectroscopy.

  12. Validation of ACE-FTS measurements of CFC-11, CFC-12, and HCFC-22 using ground-based FTIR spectrometers

    Science.gov (United States)

    Kolonjari, F.; Walker, K. A.; Mahieu, E.; Batchelor, R. L.; Bernath, P. F.; Boone, C.; Conway, S. A.; Dan, L.; Griffin, D.; Harrett, A.; Kasai, Y.; Kagawa, A.; Lindenmaier, R.; Strong, K.; Whaley, C.

    2013-12-01

    Satellite datasets can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission on-board the Canadian satellite SCISAT-1. The primary instrument on SCISAT-1 is a high-resolution infrared Fourier transform spectrometer (ACE-FTS) which is capable of measuring a range of gases including key chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) species. These families of species are of interest because of their significant contribution to anthropogenic ozone depletion and to global warming. To assess the quality of data derived from satellite measurements, validation using other data sources is essential. Ground-based Fourier transform infrared (FTIR) spectrometers are particularly useful for this purpose. In this study, five FTIR spectrometers located at four sites around the world are used to validate the CFC-11 (CCl3F), CFC-12 (CCl2F2), and HCFC-22 (CHClF2) retrieved profiles from ACE-FTS measurements. These species are related because HCFC-22 was the primary replacement for CFC-11 and CFC-12 in refrigerant and propellant applications. The FTIR spectrometers used in this study record solar absorption spectra at Eureka (Canada), Jungfraujoch (Switzerland), Poker Flat (USA), and Toronto (Canada). The retrieval of CFC-11, CFC-12, and HCFC-22 are not standard products for many of these instruments, and as such, a harmonization of retrieval parameters between the sites has been conducted. The retrievals of these species from the FTIR spectra are sensitive from the surface to approximately 20 km, while the ACE-FTS profiles extend from approximately 6 to 30 km. For each site, partial column comparisons between coincident measurements of the three species and a validation of the observed trends will be discussed.

  13. Development of Miniature Spectrometers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-guo

    2007-01-01

    Spectrometer is an essential and necessary optical element used for measuring the chemical components and content of the matter.The development of miniature spectrometers can be traced back to 1980s.The development state and different manufacturing methods of micro-spectrometers are presented.Finally,we analyze the miniaturization trend of spectrometers.Some groundwork for the scientific research is offered by introducing micro-spectrometers development.

  14. Hydrocarbons on Saturn's satellites Iapetus and Phoebe

    Science.gov (United States)

    Cruikshank, D.P.; Wegryn, E.; Dalle, Ore C.M.; Brown, R.H.; Bibring, J.-P.; Buratti, B.J.; Clark, R.N.; McCord, T.B.; Nicholson, P.D.; Pendleton, Y.J.; Owen, T.C.; Filacchione, G.; Coradini, A.; Cerroni, P.; Capaccioni, F.; Jaumann, R.; Nelson, R.M.; Baines, K.H.; Sotin, C.; Bellucci, G.; Combes, M.; Langevin, Y.; Sicardy, B.; Matson, D.L.; Formisano, V.; Drossart, P.; Mennella, V.

    2008-01-01

    Material of low geometric albedo (pV ??? 0.1) is found on many objects in the outer Solar System, but its distribution in the saturnian satellite system is of special interest because of its juxtaposition with high-albedo ice. In the absence of clear, diagnostic spectral features, the composition of this low-albedo (or "dark") material is generally inferred to be carbon-rich, but the form(s) of the carbon is unknown. Near-infrared spectra of the low-albedo hemisphere of Saturn's satellite Iapetus were obtained with the Visible-Infrared Mapping Spectrometer (VIMS) on the Cassini spacecraft at the fly-by of that satellite of 31 December 2004, yielding a maximum spatial resolution on the satellite's surface of ???65 km. The spectral region 3-3.6 ??m reveals a broad absorption band, centered at 3.29 ??m, and concentrated in a region comprising about 15% of the low-albedo surface area. This is identified as the C{single bond}H stretching mode vibration in polycyclic aromatic hydrocarbon (PAH) molecules. Two weaker bands attributed to {single bond}CH2{single bond} stretching modes in aliphatic hydrocarbons are found in association with the aromatic band. The bands most likely arise from aromatic and aliphatic units in complex macromolecular carbonaceous material with a kerogen- or coal-like structure, similar to that in carbonaceous meteorites. VIMS spectra of Phoebe, encountered by Cassini on 11 June 2004, also show the aromatic hydrocarbon band, although somewhat weaker than on Iapetus. The origin of the PAH molecular material on these two satellites is unknown, but PAHs are found in carbonaceous meteorites, cometary dust particles, circumstellar dust, and interstellar dust. ?? 2007 Elsevier Inc. All rights reserved.

  15. ASTER Urgent Response to the 2006 Eruption of Augustine Volcano, Alaska: Science and Decision Support Gained From Frequent High-resolution, Satellite Thermal Infrared Imaging of Volcanic Events

    Science.gov (United States)

    Wessels, R. L.; Ramsey, M. S.; Schneider, D. S.; Coombs, M.; Dehn, J.; Realmuto, V. J.

    2006-12-01

    Augustine Volcano, Alaska explosively erupted on January 11, 2006 after nearly eight months of increasing seismicity, deformation, gas emission, and small phreatic explosions. The volcano produced a total of 13 explosive eruptions during the last three weeks of January 2006. A new summit lava dome and two short, blocky lava flows grew during February and March 2006. A series of 7 daytime and 15 nighttime Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) scenes were acquired in response to this new activity. This response was facilitated by a new ASTER Urgent Request Protocol system. The ASTER data provided several significant observations as a part of a much larger suite of real-time or near-real-time data from other satellite (AVHRR, MODIS), airborne (FLIR, visual, gas), and ground-based (seismometers, radiometers) sensors used at the Alaska Volcano Observatory (AVO). ASTER is well-suited to volcanic observations because of its 15-m to 90-m spatial resolution, its ability to be scheduled and point off-nadir, and its ability to collect visible-near infrared (VNIR) to thermal infrared (TIR) data during both the day and night. Aided by the volcano's high latitude (59.4°N) ASTER was able to provide frequent repeat imaging as short as one day between scenes with an average 6-day repeat during the height of activity. These data provided a time series of high-resolution VNIR, shortwave infrared (SWIR - detects temperatures from about 200°C to > 600°C averaged over a 30-m pixel), and TIR (detects temperatures up to about 100°C averaged over a 90-m pixel) data of the volcano and its eruptive products. Frequent satellite imaging of volcanoes is necessary to record rapid changes in activity and to avoid recurring cloud cover. Of the 22 ASTER scenes acquired between October 30, 2005 and May 30, 2006, the volcano was clear to partly cloudy in 13 scenes. The most useful pre-eruption ASTER Urgent Request image was acquired on December 20. These data

  16. Infrared absorption of methanethiol clusters (CH3SH)n, n = 2-5, recorded with a time-of-flight mass spectrometer using IR depletion and VUV ionization.

    Science.gov (United States)

    Fu, Lung; Han, Hui-Ling; Lee, Yuan-Pern

    2012-12-21

    We investigated IR spectra in the CH- and SH-stretching regions of size-selected methanethiol clusters, (CH(3)SH)(n) with n = 2-5, in a pulsed supersonic jet using infrared (IR)-vacuum ultraviolet (VUV) ionization. VUV emission at 132.50 nm served as the source of ionization in a time-of-flight mass spectrometer. Clusters were dissociated with light from a tunable IR laser before ionization. The variations in intensity of methanethiol cluster ions (CH(3)SH)(n)(+) were monitored as the IR laser light was tuned across the range 2470-3100 cm(-1). In the SH-stretching region, the spectrum of (CH(3)SH)(2) shows a weak band near 2601 cm(-1), red-shifted only 7 cm(-1) from that of the monomer. In contrast, all spectra of (CH(3)SH)(n), n = 3-5, show a broad band near 2567 cm(-1) with much greater intensity. In the CH-stretching region, absorption bands of (CH(3)SH)(2) are located near 2865, 2890, 2944, and 3010 cm(-1), red-shifted by 3-5 cm(-1) from those of CH(3)SH. These red shifts increase slightly for larger clusters and bands near 2856, 2884, 2938, and 3005 cm(-1) were observed for (CH(3)SH)(5). These spectral results indicate that the S-H[middle dot][middle dot][middle dot]S hydrogen bond plays an important role in clusters with n = 3-5, but not in (CH(3)SH)(2), in agreement with theoretical predictions. The absence of a band near 2608 cm(-1) that corresponds to absorption of the non-hydrogen-bonded SH moiety and the large width of observed feature near 2567 cm(-1) indicate that the dominant stable structures of (CH(3)SH)(n), n = 3-5, have a cyclic hydrogen-bonded framework.

  17. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Kunduz mineral district in Afghanistan: Chapter S in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Arko, Scott A.; Harbin, Michelle L.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Kunduz mineral district, which has celestite deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2007,2008,2009), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the

  18. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Haji-Gak mineral district in Afghanistan: Chapter C in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.; Arko, Scott A.; Harbin, Michelle L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Haji-Gak mineral district, which has iron ore deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency ((c)JAXA,2006,2007), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the DS products

  19. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Kharnak-Kanjar mineral district in Afghanistan: Chapter K in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Arko, Scott A.; Harbin, Michelle L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Kharnak-Kanjar mineral district, which has mercury deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2007,2008,2010), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such

  20. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Dudkash mineral district in Afghanistan: Chapter R in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Arko, Scott A.; Harbin, Michelle L.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Dudkash mineral district, which has industrial mineral deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2006,2007,2008,2009), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS

  1. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Ghunday-Achin mineral district in Afghanistan, in Davis, P.A, compiler, Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Arko, Scott A.; Harbin, Michelle L.; Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Ghunday-Achin mineral district, which has magnesite and talc deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2008,2009), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As

  2. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Dusar-Shaida mineral district in Afghanistan: Chapter I in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Arko, Scott A.; Harbin, Michelle L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Dusar-Shaida mineral district, which has copper and tin deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the

  3. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Herat mineral district in Afghanistan: Chapter T in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Arko, Scott A.; Harbin, Michelle L.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Herat mineral district, which has barium and limestone deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2007,2008,2009), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As

  4. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Tourmaline mineral district in Afghanistan: Chapter J in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.; Arko, Scott A.; Harbin, Michelle L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Tourmaline mineral district, which has tin deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the DS products

  5. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Aynak mineral district in Afghanistan: Chapter E in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.; Arko, Scott A.; Harbin, Michelle L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Aynak mineral district, which has copper deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency ((c)JAXA,2008,2010), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the DS

  6. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Badakhshan mineral district in Afghanistan: Chapter F in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Arko, Scott A.; Harbin, Michelle L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Badakhshan mineral district, which has gold deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency ((c)JAXA,2007,2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the DS products

  7. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Kundalyan mineral district in Afghanistan: Chapter H in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.; Arko, Scott A.; Harbin, Michelle L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Kundalyan mineral district, which has porphyry copper and gold deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As

  8. Global Characterization of CO2 Column Retrievals from Shortwave-Infrared Satellite Observations of the Orbiting Carbon Observatory-2 Mission

    Directory of Open Access Journals (Sweden)

    Charles Miller

    2011-02-01

    Full Text Available The global characteristics of retrievals of the column-averaged CO2 dry air mole fraction, XCO2, from shortwave infrared observations has been studied using the expected measurement performance of the NASA Orbiting Carbon Observatory-2 (OCO-2 mission. This study focuses on XCO2 retrieval precision and averaging kernels and their sensitivity to key parameters such as solar zenith angle (SZA, surface pressure, surface type and aerosol optical depth (AOD, for both nadir and sunglint observing modes. Realistic simulations have been carried out and the single sounding retrieval errors for XCO2 have been derived from the formal retrieval error covariance matrix under the assumption that the retrieval has converged to the correct answer and that the forward model can adequately describe the measurement. Thus, the retrieval errors presented in this study represent an estimate of the retrieval precision. For nadir observations, we find single-sounding retrieval errors with values typically less than 1 part per million (ppm over most land surfaces for SZAs less than 70° and up to 2.5 ppm for larger SZAs. Larger errors are found over snow/ice and ocean surfaces due to their low albedo in the spectral regions of the CO2 absorption bands and, for ocean, also in the O2 A band. For sunglint observations, errors over the ocean are significantly smaller than in nadir mode with values in the range of 0.3 to 0.6 ppm for small SZAs which can decrease to values as small as 0.15 for the largest SZAs. The vertical sensitivity of the retrieval that is represented by the column averaging kernel peaks near the surface and exhibits values near unity throughout most of the troposphere for most anticipated scenes. Nadir observations over dark ocean or snow/ice surfaces and observations with large AOD and large SZA show a decreased sensitivity to near-surface CO2. All simulations are carried out for a mid-latitude summer atmospheric profile, a given aerosol type and

  9. Compact, Dual Channel, Mid-IR Laser Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Small Business Innovative Research Phase II proposal seeks to develop a dual channel, compact mid-infrared laser spectrometer for planetary atmosphere...

  10. Spatial Heterodyne Spectrometer for Aviation Hazard Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Physical Sciences Inc (PSI) proposes the development of a longwave infrared (LWIR) imaging spatial heterodyne spectrometer (I-SHS) for standoff detection of clear...

  11. Compact, Dual Channel, Mid-IR Laser Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Small Business Innovative Research Phase I proposal seeks to develop a dual channel, compact mid-infrared laser spectrometer for planetary atmosphere...

  12. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Kandahar mineral district in Afghanistan: Chapter Z in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Kandahar mineral district, which has bauxite deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency ((c)JAXA,2006,2007,2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the DS

  13. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Katawas mineral district in Afghanistan: Chapter N in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Katawas mineral district, which has gold deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©AXA, 2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the DS products match JAXA

  14. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the North Takhar mineral district in Afghanistan: Chapter D in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the North Takhar mineral district, which has placer gold deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2006,2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such

  15. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Uruzgan mineral district in Afghanistan: Chapter V in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Uruzgan mineral district, which has tin and tungsten deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA, 2008, 2009), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such

  16. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Ghazni1 mineral district in Afghanistan: Chapter DD in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Ghazni1 mineral district, which has spectral reflectance anomalies indicative of clay, aluminum, gold, silver, mercury, and sulfur deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency ((c)JAXA, 2008, 2009), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such

  17. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Ghazni2 mineral district in Afghanistan: Chapter EE in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Ghazni2 mineral district, which has spectral reflectance anomalies indicative of gold, mercury, and sulfur deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency ((c)JAXA, 2008, 2009), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image

  18. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Panjsher Valley mineral district in Afghanistan: Chapter M in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Panjsher Valley mineral district, which has emerald and silver-iron deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA, 2009, 2010), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from

  19. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Balkhab mineral district in Afghanistan: Chapter B in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Balkhab mineral district, which has copper deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2007,2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such, the DS products match

  20. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Bakhud mineral district in Afghanistan: Chapter U in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.; Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Bakhud mineral district, which has industrial fluorite deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2006,2007, 2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As

  1. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Zarkashan mineral district in Afghanistan: Chapter G in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Zarkashan mineral district, which has copper and gold deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2006,2007, 2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As

  2. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Takhar mineral district in Afghanistan: Chapter Q in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Takhar mineral district, which has industrial evaporite deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA, 2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such

  3. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Farah mineral district in Afghanistan: Chapter FF in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Farah mineral district, which has spectral reflectance anomalies indicative of copper, zinc, lead, silver, and gold deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency ((c)JAXA, 2007, 2008, 2010), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that

  4. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Khanneshin mineral district in Afghanistan: Chapter A in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.; Arko, Scott A.; Harbin, Michelle L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Khanneshin mineral district, which has uranium, thorium, rare-earth-element, and apatite deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420-500 nanometer, nm), green (520-600 nm), red (610-690 nm), and near-infrared (760-890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520-770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2007,2008,2010), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be

  5. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the South Helmand mineral district in Afghanistan: Chapter O in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the South Helmand mineral district, which has travertine deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA, 2008, 2010), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such

  6. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Nalbandon mineral district in Afghanistan: Chapter L in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Nalbandon mineral district, which has lead and zinc deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA, 2007, 2008, 2010), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As

  7. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Baghlan mineral district in Afghanistan: Chapter P in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.; Cagney, Laura E.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Baghlan mineral district, which has industrial clay and gypsum deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA, 2006, 2007, 2008), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from

  8. Variability of the infrared complex refractive index of African mineral dust: experimental estimation and implications for radiative transfer and satellite remote sensing

    Directory of Open Access Journals (Sweden)

    C. Di Biagio

    2014-04-01

    Full Text Available Experimental estimations of the infrared refractive index of African mineral dust have been retrieved from laboratory measurements of particle transmission spectra in the wavelength range 2.5–25 μm. Five dust samples collected at Banizoumbou (Niger and Tamanrasset (Algeria during dust events originated from different Western Saharan and Sahelian areas have been investigated. The obtained real (n and imaginary (k parts of the refractive index for the different dust cases vary in the range 1.1–2.7 and 0.05–1.0, respectively, and appear to be strongly sensitive to the mineralogical composition of the particles, especially in the 8–12 μm and 17–25 μm spectral intervals. Dust absorption is controlled mainly by clays, and, in minor fraction, by quartz and Ca-rich minerals. Size distribution, and the coarse fraction in particular, plays also a role in determining the refractive index. Significant differences are obtained when comparing our results with existing experimental estimations available in the literature, and with the values of the OPAC (Optical Properties of Aerosols and Clouds database. The different datasets appear comparable in magnitude, with our values of n and k falling in the range of variability of past studies. However, literature data fail in accurately reproducing the spectral signatures of main minerals, in particular clays, and they significantly overestimate the contribution of quartz. We also found that the real and the imaginary parts of the refractive index from part of literature studies do not verify Kramers–Kronig relations, thus resulting theoretically incorrect. The comparison between our results, from Western Africa, and literature data, from different locations in Europe, Africa, and the Caribbean, nonetheless, confirms the expected large variability of the infrared refractive index of dust, thus highlighting the necessity for an extended systematic investigation. Aerosol intensive optical properties

  9. Early On-Orbit Performance of the Visible Infrared Imaging Radiometer Suite Onboard the Suomi National Polar-Orbiting Partnership (S-NPP) Satellite

    Science.gov (United States)

    Cao, Changyong; DeLuccia, Frank J.; Xiong, Xiaoxiong; Wolfe, Robert; Weng, Fuzhong

    2014-01-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of the key environmental remote-sensing instruments onboard the Suomi National Polar-Orbiting Partnership spacecraft, which was successfully launched on October 28, 2011 from the Vandenberg Air Force Base, California. Following a series of spacecraft and sensor activation operations, the VIIRS nadir door was opened on November 21, 2011. The first VIIRS image acquired signifies a new generation of operational moderate resolution-imaging capabilities following the legacy of the advanced very high-resolution radiometer series on NOAA satellites and Terra and Aqua Moderate-Resolution Imaging Spectroradiometer for NASA's Earth Observing system. VIIRS provides significant enhancements to the operational environmental monitoring and numerical weather forecasting, with 22 imaging and radiometric bands covering wavelengths from 0.41 to 12.5 microns, providing the sensor data records for 23 environmental data records including aerosol, cloud properties, fire, albedo, snow and ice, vegetation, sea surface temperature, ocean color, and nigh-time visible-light-related applications. Preliminary results from the on-orbit verification in the postlaunch check-out and intensive calibration and validation have shown that VIIRS is performing well and producing high-quality images. This paper provides an overview of the onorbit performance of VIIRS, the calibration/validation (cal/val) activities and methodologies used. It presents an assessment of the sensor initial on-orbit calibration and performance based on the efforts from the VIIRS-SDR team. Known anomalies, issues, and future calibration efforts, including the long-term monitoring, and intercalibration are also discussed.

  10. Local-area-enhanced, 2.5-meter resolution natural-color and color-infrared satellite-image mosaics of the Parwan mineral district in Afghanistan: Chapter CC in Local-area-enhanced, high-resolution natural-color and color-infrared satellite-image mosaics of mineral districts in Afghanistan

    Science.gov (United States)

    Davis, Philip A.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Defense Task Force for Business and Stability Operations, prepared databases for mineral-resource target areas in Afghanistan. The purpose of the databases is to (1) provide useful data to ground-survey crews for use in performing detailed assessments of the areas and (2) provide useful information to private investors who are considering investment in a particular area for development of its natural resources. The set of satellite-image mosaics provided in this Data Series (DS) is one such database. Although airborne digital color-infrared imagery was acquired for parts of Afghanistan in 2006, the image data have radiometric variations that preclude their use in creating a consistent image mosaic for geologic analysis. Consequently, image mosaics were created using ALOS (Advanced Land Observation Satellite; renamed Daichi) satellite images, whose radiometry has been well determined (Saunier, 2007a,b). This part of the DS consists of the locally enhanced ALOS image mosaics for the Parwan mineral district, which has gold and copper deposits. ALOS was launched on January 24, 2006, and provides multispectral images from the AVNIR (Advanced Visible and Near-Infrared Radiometer) sensor in blue (420–500 nanometer, nm), green (520–600 nm), red (610–690 nm), and near-infrared (760–890 nm) wavelength bands with an 8-bit dynamic range and a 10-meter (m) ground resolution. The satellite also provides a panchromatic band image from the PRISM (Panchromatic Remote-sensing Instrument for Stereo Mapping) sensor (520–770 nm) with the same dynamic range but a 2.5-m ground resolution. The image products in this DS incorporate copyrighted data provided by the Japan Aerospace Exploration Agency (©JAXA,2006, 2007), but the image processing has altered the original pixel structure and all image values of the JAXA ALOS data, such that original image values cannot be recreated from this DS. As such

  11. Hyperspectral Thermal Emission Spectrometer: Engineering Flight Campaign

    Science.gov (United States)

    Johnson, William R.; Hook, Simon J.; Shoen, Steven S.; Eng, Bjorn T.

    2013-01-01

    The Hyperspectral Thermal Emission Spectrometer (HyTES) successfully completed its first set of engineering test flights. HyTES was developed in support of the Hyperspectral Infrared Imager (HyspIRI). HyspIRI is one of the Tier II Decadal Survey missions. HyTES currently provides both high spectral resolution (17 nm) and high spatial resolution (2-5m) data in the thermal infrared (7.5-12 micron) part of the electromagnetic spectrum. HyTES data will be used to help determine the optimum band positions for the HyspIRI Thermal Infrared (TIR) sensor and provide antecedent data for HyspIRI related studies.

  12. A SSS Spectrometer

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The SSS spectrometer, so called simple scintillation spectrometer, is made by BTI (Bubble Technology Industries). The spectrometer can be used in the neutron energy range from 4.0 to 17 MeV. The SSS includes two sections: A probe and an analyzer module

  13. Multispectral sensing of natural resources with the MSTI-3 satellite

    Science.gov (United States)

    Griggs, Michael; Myers, William A.; Baker, H. Vernon

    1995-01-01

    The third satellite in the miniature sensor technology integration (MSTI) program includes two infrared imaging sensors with filter wheels, and a visible imaging spectrometer, with a common telescope and gimballed scan mirror assembly. These sensors will provide high spatial and spectral resolution imagery in the visible and 2.5 - 4.5 micrometers spectral regions. These spectral regions can provide information on the atmospheric aerosol optical thickness and size distribution; the vegetation index and crop classification; upper atmosphere temperatures, and tropospheric water vapor. In addition, the highly accurate pointing and tracking capability of the scan mirror permits a long look at particular events such as volcanic eruptions, major oil-spills, desert dust storms, forest fires and air pollution episodes. This tracking capability could also support ground truth calibration of other satellite sensors.

  14. Image Monitoring of Pharmaceutical Blending Processes and the Determination of an End Point by Using a Portable Near-Infrared Imaging Device Based on a Polychromator-Type Near-Infrared Spectrometer with a High-speed and High-Resolution Photo Diode Array Detector

    Directory of Open Access Journals (Sweden)

    Kodai Murayama

    2015-03-01

    Full Text Available In the present study we have developed a new version (ND-NIRs of a polychromator-type near-infrared (NIR spectrometer with a high-resolution photo diode array detector, which we built before (D-NIRs. The new version has four 5 W halogen lamps compared with the three lamps for the older version. The new version also has a condenser lens with a shorter focal point length. The increase in the number of the lamps and the shortening of the focal point of the condenser lens realize high signal-to-noise ratio and high-speed NIR imaging measurement. By using the ND-NIRs we carried out the in-line monitoring of pharmaceutical blending and determined an end point of the blending process. Moreover, to determinate a more accurate end point, a NIR image of the blending sample was acquired by means of a portable NIR imaging device based on ND-NIRs. The imaging result has demonstrated that the mixing time of 8 min is enough for homogeneous mixing. In this way the present study has demonstrated that ND-NIRs and the imaging system based on a ND-NIRs hold considerable promise for process analysis.

  15. ASTRO-F : Infrared Imaging Surveyor (IRIS) Mission

    Science.gov (United States)

    Onaka, T.

    The ASTRO-F (also known as Infrared Imaging Surveyor: IRIS) is the second infrared satellite mission of the Institute of Space and Astronautical Science, Japan to be launched early 2004 with the M-V rocket and is planned as a second generation infrared sky survey mission. It has a 67-cm aperture telescope and is cooled by 170-liter liquid helium and Stirling-cycle coolers. Two scientific instruments share the focal plane. The infrared camera (IRC) covers 2 to 26 μm range with large two-dimensional arrays in the imaging and low-resolution spectroscopic modes and will perform deep sky surveys of selected areas of the sky with a wide field of view (10' × 10') at unprecedented sensitivity. The far-infrared Surveyor (FIS), consisting of an imaging scanner and a Fourier transform spectrometer, covers 50 to 200 μm range and makes a whole sky survey in four far-infrared bands, which is higher by more than 10 in sensitivity (20 110 mJy), better by several in the spatial resolution (30'' 50''), and longer in the spectral coverage (200 μm) than IRAS. A brief description and the current status of the ASTRO-F mission are presented.

  16. Satellite-derived methane emissions from inundation in Bangladesh

    Science.gov (United States)

    Peters, C. N.; Bennartz, R.; Hornberger, G. M.

    2017-05-01

    The uncertainty in methane (CH4) source strength of rice fields and wetlands is particularly high in South Asia CH4 budgets. We used satellite observations of CH4 column mixing ratios from Atmospheric Infrared Sounder (AIRS), Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and Greenhouse Gases Observing Satellite (GOSAT) to estimate the contribution of Bangladesh emissions to atmospheric CH4 concentrations. Using satellite-derived inundation area as a proxy for source area, we developed a simple inverse advection model that estimates average annual CH4 surface fluxes to be 4, 9, and 19 mg CH4 m-2 h-1 in AIRS, SCIAMACHY, and GOSAT, respectively. Despite this variability, our flux estimates varied over a significantly narrower range than reported values for CH4 surface fluxes from a survey of 32 studies reporting ground-based observations between 0 and 260 mg CH4 m-2 h-1. Upscaling our satellite-derived surface flux estimates, we estimated total annual CH4 emissions for Bangladesh to be 1.3 ± 3.2, 1.8 ± 2.0, 3.1 ± 1.6 Tg yr-1, depending on the satellite. Our estimates of total emissions are in line with the median of total emission values for Bangladesh reported in earlier studies.

  17. 天基红外卫星协同预警临空高速目标配置优化%Optimization of space-based infrared satellites deployment for near-space hypersonic target warning

    Institute of Scientific and Technical Information of China (English)

    谢鑫; 李为民; 黄仁全

    2015-01-01

    围绕天基红外卫星协同预警临空高速目标配置问题,考虑临空高速目标预警的任务需求和不同轨道卫星的覆盖特性,建立了 GEO、HEO 和 LEO 红外预警卫星的配置优化模型。在给定的威胁想定和传感器参数设置下,经仿真求解,构型为“5GEO +3HEO +24/4/2LEO”的天基红外预警卫星星座可满足临空高速目标防御对天基预警系统的预警需求。%Aiming at the problem of space-based infrared satellites deployment for near-space hypersonic target warning, the optimization models for the deployments of GEO,HEO and LEO infrared satellites are established respectively,ac-cording to the requirements of near-space hypersonic target warning and the coverage characteristics of satellites on dif-ferent orbits.Under the conditions of the fixed threat assumption and the sensors parameter setting,the models were sim-ulated and analyzed.The simulation results show that the space-based infrared warning system with the construction of‘5GEO +3HEO +24/4/2LEO’can satisfy the warning requirements for near-space hypersonic target defense.

  18. Infrared heterodyne spectroscopy in astronomy

    Science.gov (United States)

    Betz, A.

    1980-01-01

    A heterodyne spectrometer was constructed and applied to problems in infrared astronomical spectroscopy. The instrument offers distinct observational advantages for the detection and analysis of individual spectral lines at Doppler-limited resolution. Observations of carbon dioxide in planetary atmospheres and ammonia in circumstellar environments demonstrate the substantial role that infrared heterodyne techniques will play in the astronomical spectroscopy of the future.

  19. Design of a miniaturized integrated spectrometer for spectral tissue sensing

    Science.gov (United States)

    Belay, Gebirie Yizengaw; Hoving, Willem; Ottevaere, Heidi; van der Put, Arthur; Weltjens, Wim; Thienpont, Hugo

    2016-04-01

    Minimally-invasive image-guided procedures become increasingly used by physicians to obtain real-time characterization feedback from the tissue at the tip of their interventional device (needle, catheter, endoscopic or laparoscopic probes, etc…) which can significantly improve the outcome of diagnosis and treatment, and ultimately reduce cost of the medical treatment. Spectral tissue sensing using compact photonic probes has the potential to be a valuable tool for screening and diagnostic purposes, e.g. for discriminating between healthy and tumorous tissue. However, this technique requires a low-cost broadband miniature spectrometer so that it is commercially viable for screening at point-of-care locations such as physicians' offices and outpatient centers. Our goal is therefore to develop a miniaturized spectrometer based on diffractive optics that combines the functionalities of a visible/near-infrared (VIS/NIR) and shortwave-infrared (SWIR) spectrometer in one very compact housing. A second goal is that the hardware can be produced in high volume at low cost without expensive time consuming alignment and calibration steps. We have designed a miniaturized spectrometer which operates both in the visible/near-infrared and shortwave-infrared wavelength regions ranging from 400 nm to 1700 nm. The visible/near-infrared part of the spectrometer is designed for wavelengths from 400 nm to 800 nm whereas the shortwave-infrared segment ranges from 850 nm to 1700 nm. The spectrometer has a resolution of 6 nm in the visible/near-infrared wavelength region and 10 nm in the shortwave-infrared. The minimum SNR of the spectrometer for the intended application is about 151 in the VIS/NIR range and 6000 for SWIR. In this paper, the modelling and design, and power budget analysis of the miniaturized spectrometer are presented. Our work opens a door for future affordable micro- spectrometers which can be integrated with smartphones and tablets, and used for point

  20. Study on real-time spectrum recovery system on a FPGA chip for Fourier transform infrared imaging spectrometer%傅里叶变换红外成像光谱仪实时光谱复原FPGA芯片系统研究

    Institute of Scientific and Technical Information of China (English)

    殷世民; 梁永波; 朱健铭; 梁晋涛; 陈真诚

    2015-01-01

    In view of the real-time data processing requirements of Fourier transform infrared imaging spectrometer, a real-time spectrum recovery system on a FPGA chip for the spectrometer was studied which integrates the functions of interferogram nonuniformity correction, spectrum recovery and spectral radiation calibration. The system has made a standardized design of the input signals. It can be run in line way, output target's spectrum in real-time and be embedded in the real-time data processing system for various types of infrared/visible Fourier transform imaging spectrometer which has some specialties such as small volume, fast computing speed, good stability, high reliability and easy to upgrade. The system can establish a good technical foundation for the real-time target recognition based on the spectral characteristics.%针对傅里叶变换红外成像光谱仪实时数据处理技术的要求,研究了一种基于FPGA的集干涉图非均匀性校正、光谱复原、光谱辐射定标于一体的傅里叶变换红外成像光谱仪实时光谱复原芯片系统.该系统对输入信号做了标准化设计,以流水线方式输出目标的复原光谱信息,可嵌入到各种类型的红外/可见光傅里叶变换成像光谱仪的实时数据处理系统中,具有体积小、运算速度快、稳定可靠及易于升级等优点,为基于光谱特征的目标实时识别奠定了良好的技术基础.

  1. GHRSST Level 2P Global 1 meter Sea Surface Temperature from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on retrievals from the Visible Infrared Imaging Radiometer Suite (VIIRS)....

  2. The Canadian Arctic ACE/OSIRIS Validation Project at PEARL: Validating Satellite Observations Over the High Arctic

    Science.gov (United States)

    Walker, Kaley A.; Strong, Kimberly; Fogal, Pierre F.; Drummond, James R.

    2016-04-01

    Ground-based measurements provide critical data for the validation of satellite retrievals of atmospheric trace gases and for the assessment of long-term stability of these measurements. As of February 2016, the Canadian-led Atmospheric Chemistry Experiment (ACE) satellite mission has been making measurements of the Earth's atmosphere for nearly twelve years and Canada's Optical Spectrograph and InfraRed Imager System (OSIRIS) instrument on the Odin satellite has been operating for fourteen years. As ACE and OSIRIS operations have extended beyond their planned two-year missions, there is an ongoing need to validate the trace gas data profiles from the ACE-Fourier Transform Spectrometer (ACE-FTS), the Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (ACE-MAESTRO) and OSIRIS. In particular, validation comparisons are needed during Arctic springtime to understand better the measurements of species involved in stratospheric ozone chemistry. To this end, thirteen Canadian Arctic ACE/OSIRIS Validation Campaigns have been conducted during the spring period (February - April in 2004 - 2016) at the Polar Environment Atmospheric Research Laboratory (PEARL) in Eureka, Nunavut (80N, 86W). For the past decade, these campaigns have been undertaken in collaboration with the Canadian Network for the Detection of Atmospheric Change (CANDAC). The spring period coincides with the most chemically active time of year in the Arctic, as well as a significant number of satellite overpasses. A suite of as many as 12 ground-based instruments, as well as frequent balloon-borne ozonesonde and radiosonde launches, have been used in each campaign. These instruments include: a ground-based version of the ACE-FTS (PARIS - Portable Atmospheric Research Interferometric Spectrometer), a terrestrial version of the ACE-MAESTRO, a SunPhotoSpectrometer, two CANDAC zenith-viewing UV-visible grating spectrometers, a Bomem DA8 Fourier transform spectrometer

  3. Comparison between IASI and GOSAT retrievals in the thermal infrared

    Science.gov (United States)

    Payan, S.; Camy-peyret, C.; Bureau, J.; Shiomi, K.

    2012-04-01

    GOSAT (Greenhouse Gases Observing SATellite) is a satellite dedicated to the study of greenhouses gases. It carries an infrared Fourier transform spectrometer (The Thermal and Near Infrared Sensor for Carbon Observation Fourier-Transform Spectrometer or TANSO-FTS), which acquires spectra in 4 bands, located in the Near-Infrared (NIR), ShortWave Infrared (SWIR) and Thermal Infrared (TIR). An imager (CAI: Cloud and Aerosols imager) enables to gain information on clouds and aerosols, and this information is used to improve the quality of CO2 and CH4 retrievals. IASI (Infrared Atmospheric Sounding Interferometer) designed by CNES for Eumetsat is carried by the MetOp-A satellite. It is used for operational meteorology and is also interesting for greenhouse gases as well as for atmospheric chemistry and climate. We looked for close spatial and temporal coincidences between IASI and TANSO-FTS nadir spectra. Due to the respective orbits of MetOp-A and GOSAT, this is only achieved at high latitudes. We compared the surface temperature, CO2, CH4, N2O and O3 mixing ratios retrieved from TANSO-FTS and from IASI spectra. We used the [940;980] cm-1 window for CO2 (laser band), [1240;1320] cm-1 for CH4, [1140;1200] cm-1 for N2O, and [980;1100] cm-1 for O3. Since IASI is considered as a reference for radiometric calibrations, we compared the surface temperatures retrieved by GOSAT and IASI in these different windows to assess the GOSAT radiometric calibration. The GOSAT/IASI comparison is done on surface temperature rather than on raw radiances because the different instrumental noise and spectral resolution of these instruments make a direct comparison of the radiances more difficult. The use of different spectral windows enabled us to explore the spectral dependence of the TANSO-FTS radiometric calibration. Cloud-free and spatially homogenous fields of view (IFOVs) were selected using CAI images. Finally, we will show the potential to further improve the results using the

  4. Fluorescence imaging spectrometer optical design

    Science.gov (United States)

    Taiti, A.; Coppo, P.; Battistelli, E.

    2015-09-01

    The optical design of the FLuORescence Imaging Spectrometer (FLORIS) studied for the Fluorescence Explorer (FLEX) mission is discussed. FLEX is a candidate for the ESA's 8th Earth Explorer opportunity mission. FLORIS is a pushbroom hyperspectral imager foreseen to be embarked on board of a medium size satellite, flying in tandem with Sentinel-3 in a Sun synchronous orbit at a height of about 815 km. FLORIS will observe the vegetation fluorescence and reflectance within a spectral range between 500 and 780 nm. Multi-frames acquisitions on matrix detectors during the satellite movement will allow the production of 2D Earth scene images in two different spectral channels, called HR and LR with spectral resolution of 0.3 and 2 nm respectively. A common fore optics is foreseen to enhance by design the spatial co-registration between the two spectral channels, which have the same ground spatial sampling (300 m) and swath (150 km). An overlapped spectral range between the two channels is also introduced to simplify the spectral coregistration. A compact opto-mechanical solution with all spherical and plane optical elements is proposed, and the most significant design rationales are described. The instrument optical architecture foresees a dual Babinet scrambler, a dioptric telescope and two grating spectrometers (HR and LR), each consisting of a modified Offner configuration. The developed design is robust, stable vs temperature, easy to align, showing very high optical quality along the whole field of view. The system gives also excellent correction for transverse chromatic aberration and distortions (keystone and smile).

  5. a Portable Dual Frequency Comb Spectrometer for Atmospheric Applications

    Science.gov (United States)

    Cossel, Kevin C.; Waxman, Eleanor; Truong, Gar-Wing; Giorgetta, Fabrizio; Swann, William C.; Coburn, Sean; Wright, Robert; Rieker, Greg B.; Coddington, Ian; Newbury, Nathan R.

    2016-06-01

    Dual frequency comb (DFC) spectroscopy is a new technique that combines broad spectral bandwidth, high spectral resolution, rapid data acquisition, and high sensitivity. In addition, unlike standard Fourier-transform spectroscopy, it has an almost ideal instrument lineshape function, does not require recalibration, and has no moving parts. These features make DFC spectroscopy well suited for accurate measurements of multiple species simultaneously. Because the frequency comb lasers can be well collimated, such a system can be used for long open-path measurements with path lengths ranging from hundreds of meters to several kilometers. This length scale bridges the gap between point measurements and satellite-based measurements and is ideal for providing information about local sources and quantifying emissions. Here we show a fully portable DFC spectrometer operating over a wide spectral region in the near-infrared (about 1.5-2.1 μm or 6670-4750 cm-1 sampled at 0.0067 cm-1) and across several different open-air paths up to a path length of 11.8 km. The current spectrometer fits in about a 500 L volume and has low power consumption. It provides simultaneous measurements of CO_2, CH_4, and water isotopes with a time resolution of seconds to minutes. This system has several potential applications for atmospheric measurements including continuous monitoring city-scale emissions and localizing methane leaks from oil and gas wells. G. B. Rieker, F. R. Giorgetta, W. C. Swann, J. Kofler, A. M. Zolot, L. C. Sinclair, E. Baumann, C. Cromer, G. Petron, C. Sweeney, P. P. Tans, I. Coddington, and N. R. Newbury, Frequency-comb-based remote sensing of greenhouse gases over kilometer air paths, Optica, 1(5), 290-298 (2014).

  6. Saturn's satellites - Near-infrared spectrophotometry (0.65-2.5 microns) of the leading and trailing sides and compositional implications

    Science.gov (United States)

    Steele, A.; Clark, R. N.; Brown, R. H.; Owensby, P. D.

    1984-01-01

    Water ice absorptions at 2.0, 1.5, and 1.25 microns are noted in near-IR spectra of Tethys, Dione, Rhea, Iapetus, and Hyperion, and the weak 1.04-micron ice absorption, which is detected for Rhea and Dione, is studied to establish band depth upper limits. The leading-trailing side 1.04-micron ice band depth differences on Saturn's satellites are similar to those for the Galilean satellites, indicating possible surface modification by magnetospheric charged particle bombardment. Limits are obtained for the amounts of particulates, trapped gases, and ammonium hydroxide on the surface. With the exception of the dark side of Iapetus, the surfaces of all of Saturn's satellites are nearly pure ice water.

  7. Non-Contact Measurement of the Spectral Emissivity through Active/Passive Synergy of CO₂ Laser at 10.6 µm and 102F FTIR (Fourier Transform Infrared) Spectrometer

    National Research Council Canada - National Science Library

    Zhang, Ren-Hua; Su, Hong-Bo; Tian, Jing; Mi, Su-Juan; Li, Zhao-Liang

    2016-01-01

    ... is an important way to close the underdetermined equations for thermal infrared radiation. Based on the prior research results of both the authors and others, this paper proposes a new approach of obtaining the spectral...

  8. Non-Contact Measurement of the Spectral Emissivity through Active/Passive Synergy of CO2 Laser at 10.6 µm and 102F FTIR (Fourier Transform Infrared) Spectrometer

    National Research Council Canada - National Science Library

    Ren-Hua Zhang; Hong-Bo Su; Jing Tian; Su-Juan Mi; Zhao-Liang Li

    2016-01-01

    ... is an important way to close the underdetermined equations for thermal infrared radiation. Based on the prior research results of both the authors and others, this paper proposes a new approach of obtaining the spectral...

  9. The SAGE spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Pakarinen, J.; Papadakis, P. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Sorri, J.; Greenlees, P.T.; Jones, P.; Julin, R.; Konki, J.; Rahkila, P.; Sandzelius, M. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Herzberg, R.D.; Butler, P.A.; Cox, D.M.; Cresswell, J.R.; Mistry, A.; Page, R.D.; Parr, E.; Sampson, J.; Seddon, D.A.; Thornhill, J.; Wells, D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Coleman-Smith, P.J.; Lazarus, I.H.; Letts, S.C.; Pucknell, V.F.E.; Simpson, J. [STFC Daresbury Laboratory, Warrington (United Kingdom)

    2014-03-15

    The SAGE spectrometer has been constructed for in-beam nuclear structure studies. SAGE combines a Ge-detector array and an electron spectrometer for detection of γ-rays and internal conversion electrons, respectively, and allows simultaneous observation of both electrons and γ-rays emitted from excited nuclei. SAGE is set up in the Accelerator Laboratory of the University of Jyvaeskylae and works in conjunction with the RITU gas-filled recoil separator and the GREAT focal-plane spectrometer allowing the use of the recoil-decay tagging method. (orig.)

  10. [A review of Dyson optical system in the measure of infrared imaging spectrum].

    Science.gov (United States)

    Liu, Yu-juan; Tang, Yu-guo; Bayanheshig; Cui, Ji-cheng; Qi, Xiang-dong

    2012-02-01

    It is difficult for the traditional infrared imaging spectrometers to satisfy the requirement of high signal to noise ratio (SNR) and small size simultaneously. The new infrared remote sensing imaging spectrometers based on Dyson concentric optical configuration have the advantages of high aperture, high SNR, simpleness small volume and low weight. The Dyson imaging spectrometers can achieve high SNR, which is difficult for the traditional imaging spectrometers for infrared imaging spectrum. The present review introduces the beginning, the development and the present research of the Dyson imaging spectrometers, especially illustrates the principle of Dyson concentric spectrometer, difficulty during its manufacture and the application in the high-performance infrared remote sensing imaging spectrometers, providing a reference for the high-performance research of infrared remote sensing imaging spectrometers.

  11. Development and characterization of Carbon Observing Satellite

    Science.gov (United States)

    Zhang, Hang; Lin, Chao; Zheng, Yuquan; Wang, Wenquan; Tian, Longfei; Liu, Dongbin; Li, Shuai

    2016-04-01

    Carbon Observing Satellite (Tan-Sat) is the first satellite of China designed to monitor column-averaged atmospheric carbon dioxide (X) by detecting gas absorption spectra of the solar shortwave infrared radiation reflected from the Earth's surface and atmosphere. Two instruments are accommodated on Tan-Sat: the high resolution hyperspectral sensor for carbon observation grating spectrometer (HRHS-GS) and the cloud and aerosol polarimetric imager (CAPI). HRHS-GS will provide the space-based measurements of CO2 on a scale and with the accuracy and precision to quantify terrestrial sources and sinks of CO2. CAPI is used to identify the contamination by optically thick clouds and to minimize the impact of scattering by aerosol. These two instruments work together to collect global column CO2 concentrations with correction for cloud and aerosol contamination. The instrument design of HRHS-GS is presented. Ocean reflectivity and the incident radiation of the instrument for transverse electric and transverse magnetic polarizations in glint mode are discussed. The changes to glint mode operation are described. The spectral characteristics of HRHS-GS were determined through the laser-based spectral calibration. The onboard spectral calibration method based on spectrum matching is introduced. The availability was verified, satisfying the onboard spectral calibration accuracy requirement of better than Δλ/10 (Δλ is spectral resolution).

  12. Improved Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Improved Mass Spectrometer project will develop system requirements and analyze the path to space qualification.   The results of this project...

  13. Fourier Transform Spectrometer System

    Science.gov (United States)

    Campbell, Joel F. (Inventor)

    2014-01-01

    A Fourier transform spectrometer (FTS) data acquisition system includes an FTS spectrometer that receives a spectral signal and a laser signal. The system further includes a wideband detector, which is in communication with the FTS spectrometer and receives the spectral signal and laser signal from the FTS spectrometer. The wideband detector produces a composite signal comprising the laser signal and the spectral signal. The system further comprises a converter in communication with the wideband detector to receive and digitize the composite signal. The system further includes a signal processing unit that receives the composite signal from the converter. The signal processing unit further filters the laser signal and the spectral signal from the composite signal and demodulates the laser signal, to produce velocity corrected spectral data.

  14. [The principle and analysis of micro-Fourier transform spectrometer based on MEMS micro-mirror].

    Science.gov (United States)

    Chen, Jian-Jun; Zhu, Yong; Liu, Bo; Wei, Wei; Zhang, Jie; Wang, Ning

    2012-11-01

    The present paper puts forward a novel micro-Fourier transform infrared spectrometer based on programmable MEMS micro-mirror. This design uses a MEMS micro-mirror and a slantwise reflector to replace the moving mirror system on traditional spectrometer. This paper analyzes the operating principle of this spectrometer and gives the simulation result to prove the feasibility of this method. The results show that the spectral resolution is less than 5 nm in near-infrared wave band, the wave-length accuracy is approximately 1 nm and the sampling period of this spectrometer is approximately 50 ms. This method can use Hadamard transform to improve the SNR.

  15. Advances in satellite oceanography

    Science.gov (United States)

    Brown, O. B.; Cheney, R. E.

    1983-01-01

    Technical advances and recent applications of active and passive satellite remote sensing techniques to the study of oceanic processes are summarized. The general themes include infrared and visible radiometry, active and passive microwave sensors, and buoy location systems. The surface parameters of sea surface temperature, windstream, sea state, altimetry, color, and ice are treated as applicable under each of the general methods.

  16. Artificial intelligence for geologic mapping with imaging spectrometers

    Science.gov (United States)

    Kruse, F. A.

    1993-01-01

    This project was a three year study at the Center for the Study of Earth from Space (CSES) within the Cooperative Institute for Research in Environmental Science (CIRES) at the University of Colorado, Boulder. The goal of this research was to develop an expert system to allow automated identification of geologic materials based on their spectral characteristics in imaging spectrometer data such as the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). This requirement was dictated by the volume of data produced by imaging spectrometers, which prohibits manual analysis. The research described is based on the development of automated techniques for analysis of imaging spectrometer data that emulate the analytical processes used by a human observer. The research tested the feasibility of such an approach, implemented an operational system, and tested the validity of the results for selected imaging spectrometer data sets.

  17. Ballistic missile tracking performance in boost phase based on dual infrared early warning satellites%红外预警双星弹道导弹主动段跟踪性能

    Institute of Scientific and Technical Information of China (English)

    钟宇; 吴晓燕; 黄树彩; 吴建峰; 李成景; 唐意东

    2015-01-01

    为研究反导作战中红外预警卫星系统对弹道导弹主动段弹道的跟踪性能,提出以后验克拉美-罗下界(Posterior Cramer-Rao Lower Bound, PCRLB)为衡量指标,结合8态重力转弯主动段运动模型和双星纯方位无源定位获取的量测量,系统分析了运动建模精度、量测精度、采样周期、测源不确定性下检测概率和虚警数目等因素对跟踪时效性和准确性的影响.仿真算例给出了上述因素对位置和速度跟踪性能的影响程度和规律,可为预警卫星反导作战、战技指标关联建模以及星载探测器优化设计等提供有意义的参考.%To study the ballistic missile tracking performance in boost phase based on infrared early warning satellites system, Posterior Cramer-Rao Lower Bound (PCRLB) was proposed as a measurement index. After modeling ballistic target motion by 8-state gravity turn model and locating target position by dual satellites' bearing-only passive localization, PCRLB was used to evaluate the effects of factors, including target motion model accuracy, measurement accuracy, sampling period, detection probability and false alarm number conditioned by measurement origin uncertainty, on tracking timeliness and accuracy. One simulation example showed the extent and rules of said factors on position and tracking performance of velocity. It can contribute to the anti-ballistic missile operation by early warning satellite, the relationship modeling between tactical and technical indices and the optimal design of satellite-based infrared detector.

  18. Thermal stabilization of static single-mirror Fourier transform spectrometers

    Science.gov (United States)

    Schardt, Michael; Schwaller, Christian; Tremmel, Anton J.; Koch, Alexander W.

    2017-05-01

    Fourier transform spectroscopy has become a standard method for spectral analysis of infrared light. With this method, an interferogram is created by two beam interference which is subsequently Fourier-transformed. Most Fourier transform spectrometers used today provide the interferogram in the temporal domain. In contrast, static Fourier transform spectrometers generate interferograms in the spatial domain. One example of this type of spectrometer is the static single-mirror Fourier transform spectrometer which offers a high etendue in combination with a simple, miniaturized optics design. As no moving parts are required, it also features a high vibration resistance and high measurement rates. However, it is susceptible to temperature variations. In this paper, we therefore discuss the main sources for temperature-induced errors in static single-mirror Fourier transform spectrometers: changes in the refractive index of the optical components used, variations of the detector sensitivity, and thermal expansion of the housing. As these errors manifest themselves in temperature-dependent wavenumber shifts and intensity shifts, they prevent static single-mirror Fourier transform spectrometers from delivering long-term stable spectra. To eliminate these shifts, we additionally present a work concept for the thermal stabilization of the spectrometer. With this stabilization, static single-mirror Fourier transform spectrometers are made suitable for infrared process spectroscopy under harsh thermal environmental conditions. As the static single-mirror Fourier transform spectrometer uses the so-called source-doubling principle, many of the mentioned findings are transferable to other designs of static Fourier transform spectrometers based on the same principle.

  19. Satellite Communication.

    Science.gov (United States)

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  20. Usage and routine maintenance of TENSON 27 Fourier transform infrared spectrometer%T ENSOR27傅里叶变换红外光谱仪的使用与日常维护

    Institute of Scientific and Technical Information of China (English)

    张远方

    2014-01-01

    介绍了T ENSON 27型傅立叶变换红外光谱仪的特点和工作原理,以及在安装使用过程中注意事项和日常维护,同时还介绍了样品测试及样品制备的方法。%This paper mainly introduces the characteristics and operational principle of TENSON 27 FT-IR spectrometer ,and discusses the attentions of routine maintenance .The methods of sample testing and sample preparation are described at same time .

  1. OH-asterisk (7-5) Meinel band dayglow and nightglow measured by the SME limb scanning near infrared spectrometer - Comparison of the observed seasonal variability with two-dimensional model simulations

    Science.gov (United States)

    Le Texier, H.; Solomon, S.; Thomas, R. J.; Garcia, R. R.

    1989-01-01

    Seasonal variations of the OH-asterisk (7-5) mesospheric hydroxyl emission at 1.89 microns observed by the SME near-IR spectrometer are compared with the theoretical predictions of a two-dimensional dynamical/chemical model. The good agreement found at low latitudes for both dayglow and nightglow provides support for the model assumption that breaking gravity waves induce seasonal and latitudinal variations in diffusion. The seasonal behavior of atomic hydrogen in the upper mesosphere (related to vertical transport) and/or uncertainties in the OH Meinel band parameters are proposed as possible explanations for the discrepancy noted between model and observational data for the middle latitudes.

  2. A micromachined mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Petzold, G.; Siebert, P.; Mueller, J. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Dept. of Microsystemtechnology

    2001-07-01

    This paper presents the concept, the processing and the simulated and measured characteristics of a miniaturised mass spectrometer, with dimensions of approximately only a few cm{sup 3}. The mass spectrometer consists of three main parts to be manufactured by micro structuring: an electron source, an ionisation chamber including accelerating and focusing units and a mass analyser with detector. Its fabrication is based on techniques used in micro-system processing and in particular anisotropic etching, thin film deposition, electroplating, and anodic bonding. The aim of the concept for this micro mass spectrometer is not only to scale down a macroscopic system but it also takes advantage of the added features of a micro system, i.e. a high Knudsen number of about 3 at a pressure of a few Pascal, and high field strengths at a relatively low voltage. Therefore, the demands on the vacuum systems and the electrical circuits are much more simple compared to a macroscopic mass spectrometer. In the presented design of the micro mass spectrometer the resolution is in the range of 10 to 20 at a sensitivity of several tens of ppm. (orig.)

  3. Use of a Fourier transform spectrometer on a balloon-borne telescope and at the multiple mirror telescope (MMT)

    Science.gov (United States)

    Traub, W. A.; Chance, K. V.; Brasunas, J. C.; Vrtilek, J. M.; Carleton, N. P.

    1982-01-01

    The design and use of an infrared Fourier transform spectrometer which has been used for observations of laboratory, stratospheric, and astronomical spectra are described. The spectrometer has a spectral resolution of 0.032/cm and has operated in the mid-infrared (12 to 13 microns) as well as the far-infrared (40 to 140 microns), using both bolometer and photoconductor cryogeni