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Sample records for airborne radiometric measurements

  1. RADIOMETRIC CALIBRATION OF AIRBORNE LASER SCANNING DATA

    Pilarska Magdalena

    2016-01-01

    Airborne laser scanning (ALS) is widely used passive remote sensing technique. The radiometric calibration of ALS data is presented in this article. This process is a necessary element in data processing since it eliminates the influence of the external factors on the obtained values of radiometric features such as range and incidence angle. The datasets were captured with three different laser scanners; since each of these operates at a different wavelength (532, 106 4 and 1550 nm) th...

  2. Simultaneous Retrieval of Aerosol and Surface Optical Properties from Combined Airborne- and Ground-Based Direct and Diffuse Radiometric Measurements

    Gatebe, C. K.; Dubovik, O.; King, M. D.; Sinyuk, A.

    2010-01-01

    This paper presents a new method for simultaneously retrieving aerosol and surface reflectance properties from combined airborne and ground-based direct and diffuse radiometric measurements. The method is based on the standard Aerosol Robotic Network (AERONET) method for retrieving aerosol size distribution, complex index of refraction, and single scattering albedo, but modified to retrieve aerosol properties in two layers, below and above the aircraft, and parameters on surface optical properties from combined datasets (Cloud Absorption Radiometer (CAR) and AERONET data). A key advantage of this method is the inversion of all available spectral and angular data at the same time, while accounting for the influence of noise in the inversion procedure using statistical optimization. The wide spectral (0.34-2.30 m) and angular range (180 ) of the CAR instrument, combined with observations from an AERONET sunphotometer, provide sufficient measurement constraints for characterizing aerosol and surface properties with minimal assumptions. The robustness of the method was tested on observations made during four different field campaigns: (a) the Southern African Regional Science Initiative 2000 over Mongu, Zambia, (b) the Intercontinental Transport Experiment-Phase B over Mexico City, Mexico (c) Cloud and Land Surface Interaction Campaign over the Atmospheric Radiation Measurement (ARM) Central Facility, Oklahoma, USA, and (d) the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) over Elson Lagoon in Barrow, Alaska, USA. The four areas are dominated by different surface characteristics and aerosol types, and therefore provide good test cases for the new inversion method.

  3. Broadband Radiometric LED Measurements

    Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

    2016-01-01

    At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(��) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irr...

  4. Broadband radiometric LED measurements

    Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

    2016-09-01

    At present, broadband radiometric LED measurements with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

  5. Recent advances in airborne radiometric technology

    Jobst, J.E.

    1985-01-01

    Since its inception, the DOE Remote Sensing Laboratory has made dramatic innovations in airborne radiometric technology. In the past few years there have been at least four major changes in operational philosophy. (1) The helicopter is now the prime radiation survey vehicle. Surveys are conducted at low speed and low altitude, with lines spaced only a few hundred feet apart. Radiation anomalies and subtle changes in background can be readily identified. (2) Much greater emphasis is now placed on accurate, detailed analysis and interpretation of radiation data. Dramatic improvements in survey hardware and software provide much more data of considerably better quality. (3) Recent Laboratory research has been concentrated on error-free, positive identification of point radiation sources. In the past, the extent and magnitude of dispersed sources were the major concerns. (4) Integrated remote sensing has been strongly emphasized at the Laboratory in recent years. This involves the simultaneous use of radiation detectors, aerial cameras, and the multispectral scanner imagery. The synergistic effects of such data correlation are of significantly greater value in analyzing the terrestrial environment. Many of the changes in operational philosophy are directly traceable to new or dramatically improved hardware and software employed at the Laboratory. Six items have been instrumental in the above technological advances: (1) the UHF Transponder System and its predecessor, the Microwave Ranging System; (2) Model IC of the REDAR data acquisition system; (3) the development of the search algorithm; (4) continued improvements in the REDACA data analysis system; (5) deployment of polyscin sodium iodide radiation detectors; and (6) development of the Graphic Overview System

  6. Airborne radiometric: Data evaluation and calibration

    Wendt, I.; Sengpiel, K.P.; Lenz, H.

    1984-01-01

    The airborne geophysical system of the BGR (German Geological Survey) consists of a helicopter equipped with an electromagnetic system with two transmittors and two receivers, a proton resonance magnetometer and a 16 L NaJ-crystal with four channel recording. All these data together with navigation data and flight altitude above ground are recorded each second on a nine track magnetic tape for further data evaluation. Different corrections have to be applied to the rough data such as: smoothing by means of a digital filter to reduce statistical noise, altitude correction, Compton-correction, and drift correction (cross-profile evaluation). Then the corrected measuring data are combined with the navigation data in order to be able to produce iso-line maps. The final results are presented as: line plots for U, Th, and K (and EM-data and magnetometer data); actual flight line plots; iso-line maps for U, Th, and K; iso-line maps for conductivity; depth of conducting layer; and magnetometry maps. The procedures of correction and evaluation of the above mentioned data as well as the calibration of the NaJ-detector in terms of ppm U, Th, and %K are dicussed in the paper. (author)

  7. Radiometric temperature measurements fundamentals

    Zhang, Zhuomin M; Machin, Graham

    2009-01-01

    This book describes the theory of radiation thermometry, both at a primary level and for a variety of applications, such as in the materials processing industries and remote sensing. This book is written for those who will apply radiation thermometry in industrial practice; use radiation thermometers for scientific research; the radiation thermometry specialist in a national measurement institute; developers of radiation thermometers who are working to innovate products for instrument manufacturers, and developers of non-contact thermometry methods to address challenging thermometry problems.

  8. Pilot study of the application of Tellus airborne radiometric and soil geochemical data for radon mapping

    Appleton, J.D. [British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom)], E-mail: jda@bgs.ac.uk; Miles, J.C.H.; Green, B.M.R. [Health Protection Agency (HPA) - Radiation Protection Division, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Larmour, R. [Environment and Heritage Service, Department of the Environment, Belfast BT7 2JA (United Kingdom)

    2008-10-15

    The scope for using Tellus Project airborne gamma-ray spectrometer and soil geochemical data to predict the probability of houses in Northern Ireland having high indoor radon concentrations is evaluated, in a pilot study in the southeast of the province, by comparing these data statistically with in-house radon measurements. There is generally good agreement between radon maps modelled from the airborne radiometric and soil geochemical data using multivariate linear regression analysis and conventional radon maps which depend solely on geological and indoor radon data. The radon maps based on the Tellus Project data identify some additional areas where the radon risk appears to be relatively high compared with the conventional radon maps. One of the ways of validating radon maps modelled on the Tellus Project data will be to carry out additional indoor measurements in these areas.

  9. Merging airborne and carborne radiometric data for surveying the Deir Az-Zor area, Syria

    Jubeli, Y.M.; Aissa, M.; Al-Hent, R.

    1997-01-01

    To complete the radiometric map of Syria, and to estimate the natural background radiation levels for environmental monitoring, a carborne survey was undertaken over the Deir Az-Zor area. This area was not covered by a previous airborne survey, except for peripheral regions in the south and west. To complete the radiometric map, results of the carborne and airborne surveys had to be merged. This paper presents the merging procedure which was used after normalizing the two data sets to match each other. No anomalies suitable for radioelement exploration were found. However, the overall radiometric maps resulting from the present work were consistent with the maps of the areas covered by the airborne survey. (author)

  10. Remote sensing, airborne radiometric survey and aeromagnetic survey data processing and analysis

    Dong Xiuzhen; Liu Dechang; Ye Fawang; Xuan Yanxiu

    2009-01-01

    Taking remote sensing data, airborne radiometric data and aero magnetic survey data as an example, the authors elaborate about basic thinking of remote sensing data processing methods, spectral feature analysis and adopted processing methods, also explore the remote sensing data combining with the processing of airborne radiometric survey and aero magnetic survey data, and analyze geological significance of processed image. It is not only useful for geological environment research and uranium prospecting in the study area, but also reference to applications in another area. (authors)

  11. Radiometric measuring method for egg shells

    Forberg, S; Svaerdstroem, K

    1973-02-01

    A description is given of a fast nondestructive radiometric method for registration of the thickness of egg shells of the tawny owl, hen, osprey, and Canada goose. Certain errors are discussed. Measurement of the thickness of egg shells (mineral content per cm/sup 2/) with an accuracy better than 1% is possible in less than one minute under field conditions. (auth)

  12. Interpretation of Airborne Radiometric and Magnetic Data in the ...

    Wadi Millaha area is located in the North Eastern Desert of Egypt. It has been systematically surveyed using airborne gamma-ray spectrometric and magnetic methods. In the present study, the identification of both uranium and thorium anomalies has been mainly based on examining a set of composite spectrometric ...

  13. Analysis of airborne radiometric data. Volume 3. Topical reports

    Reed, J.H.; Shreve, D.C.; Sperling, M.; Woolson, W.A.

    1978-05-01

    This volume consists of four topical reports: a general discussion of the philosophy of unfolding spectra with continuum and discrete components, a mathematical treatment of the effects of various physical parameters on the uncollided gamma-ray spectrum at aircraft elevations, a discussion of the application of the unfolding code MAZNAI to airborne data, and a discussion of the effects of the nonlinear relationship between energy deposited and pulse height in NaI(T1) detectors

  14. Synoptic view of the different domains of application of airborne radiometric and spectrometric surveys in egypt

    Fouad, K.M.

    1998-01-01

    Airborne radiometric survey has been applied for more than three decades in egypt. Experience gained from the acquired data over different geological environments has revealed the importance of this geophysical tool in: 1. disclosure of anomalies of potential uranium deposits, 2. geological mapping, 3. environmental monitoring of natural radiometric background around nuclear facilities, as well as the detection of nuclear fallout resulting from local or foreign nuclear activities. The advent of recording of the discriminated gamma ray energies in the airborne 256-channel spectrometer has eventually resulted in the quantitative detection of uranium, thorium, and potassium and their elemental ratios in the rocks. This has greatly widened the scope of geophysical and geochemical application. When this type is coupled with airborne magnetometry, the geological and structural configuration is appreciably revealed in three dimensions. The important role played by the statistical method of analysis is also shown. Case histories from the eastern desert, and sinai peninsula, are exhibited to help manifest the wide variety of applications of radiometric and spectrometric surveys

  15. Radiometric measurement independent of profile. Belt weighers

    Otto, J.

    1986-01-01

    Radiometric measuring techniques allow contactless determination of the material carried by belt conveyors. Data defining the material is obtained via attenuation of gamma rays passing through the material on the belt. The method applies the absorption law according to Lambert-Beer, which has to be corrected by a build-up factor because of the stray radiation induced by the Compton effect. The profile-dependent error observed with conventional radiometric belt weighers is caused by the non-linearity of the absorption law in connection with the simultaneous summation of the various partial rays in a detector. The scanning method allows separate evaluation of the partial rays' attenuation and thus yields the correct data of the material carried, regardless of the profile. The scanning method is applied on a finite number of scanning sections, and a residual error has to be taken into account. The stochastics of quantum emission and absorption leads to an error whose expectation value is to be taken into account in the scanning algorithm. As the conveyor belt is in motion during the process of measurements, only part of the material conveyed is irradiated. The resulting assessment error is investigated as a function of the autocorrelation function of the material on the belt. (orig./HP) [de

  16. RADIOMETRIC NORMALIZATION OF LARGE AIRBORNE IMAGE DATA SETS ACQUIRED BY DIFFERENT SENSOR TYPES

    S. Gehrke

    2016-06-01

    Full Text Available Generating seamless mosaics of aerial images is a particularly challenging task when the mosaic comprises a large number of im-ages, collected over longer periods of time and with different sensors under varying imaging conditions. Such large mosaics typically consist of very heterogeneous image data, both spatially (different terrain types and atmosphere and temporally (unstable atmo-spheric properties and even changes in land coverage. We present a new radiometric normalization or, respectively, radiometric aerial triangulation approach that takes advantage of our knowledge about each sensor’s properties. The current implementation supports medium and large format airborne imaging sensors of the Leica Geosystems family, namely the ADS line-scanner as well as DMC and RCD frame sensors. A hierarchical modelling – with parameters for the overall mosaic, the sensor type, different flight sessions, strips and individual images – allows for adaptation to each sensor’s geometric and radiometric properties. Additional parameters at different hierarchy levels can compensate radiome-tric differences of various origins to compensate for shortcomings of the preceding radiometric sensor calibration as well as BRDF and atmospheric corrections. The final, relative normalization is based on radiometric tie points in overlapping images, absolute radiometric control points and image statistics. It is computed in a global least squares adjustment for the entire mosaic by altering each image’s histogram using a location-dependent mathematical model. This model involves contrast and brightness corrections at radiometric fix points with bilinear interpolation for corrections in-between. The distribution of the radiometry fixes is adaptive to each image and generally increases with image size, hence enabling optimal local adaptation even for very long image strips as typi-cally captured by a line-scanner sensor. The normalization approach is implemented in

  17. Inverting radiometric measurements with a neural network

    Measure, Edward M.; Yee, Young P.; Balding, Jeff M.; Watkins, Wendell R.

    1992-02-01

    A neural network scheme for retrieving remotely sensed vertical temperature profiles was applied to observed ground based radiometer measurements. The neural network used microwave radiance measurements and surface measurements of temperature and pressure as inputs. Because the microwave radiometer is capable of measuring 4 oxygen channels at 5 different elevation angles (9, 15, 25, 40, and 90 degs), 20 microwave measurements are potentially available. Because these measurements have considerable redundancy, a neural network was experimented with, accepting as inputs microwave measurements taken at 53.88 GHz, 40 deg; 57.45 GHz, 40 deg; and 57.45, 90 deg. The primary test site was located at White Sands Missile Range (WSMR), NM. Results are compared with measurements made simultaneously with balloon borne radiosonde instruments and with radiometric temperature retrievals made using more conventional retrieval algorithms. The neural network was trained using a Widrow-Hoff delta rule procedure. Functions of date to include season dependence in the retrieval process and functions of time to include diurnal effects were used as inputs to the neural network.

  18. Analysis of Properties of Reflectance Reference Targets for Permanent Radiometric Test Sites of High Resolution Airborne Imaging Systems

    Eero Ahokas

    2010-08-01

    Full Text Available Reliable and optimal exploitation of rapidly developing airborne imaging methods requires geometric and radiometric quality assurance of production systems in operational conditions. Permanent test sites are the most promising approach for cost-efficient performance assessment. Optimal construction of permanent radiometric test sites for high resolution airborne imaging systems is an unresolved issue. The objective of this study was to assess the performance of commercially available gravels and painted and unpainted concrete targets for permanent, open-air radiometric test sites under sub-optimal climate conditions in Southern Finland. The reflectance spectrum and reflectance anisotropy and their stability were characterized during the summer of 2009. The management of reflectance anisotropy and stability were shown to be the key issues for better than 5% reflectance accuracy.

  19. Complex optimization of radiometric control and measurement systems

    Onishchenko, A.M.

    1995-01-01

    Fundamentals of a new approach to increase in the accuracy of radiometric systems of control and measurements are presented in succession. Block diagram of the new concept of radiometric system optimization is provided. The approach involving radical increase in accuracy and envisages ascertaining of controlled parameter by the totality of two intelligence signals closely correlated with each other. The new concept makes use of system analysis as a unified one-piece object, permitting euristic synthesis of the system. 4 refs., 3 figs

  20. Karoo airborne geophysical survey: preliminary report on airborne radiometric data from block 12

    Day, R.W.; Wright, O.M.

    1980-02-01

    The analogue gamma-ray spectrometer records of block 12 of the Karoo airborne geophysical survey were studied and significant uranium anomalies were selected and graded. The anomalies were plotted on 1:50 000 scale maps and the co-ordinates of the anomalies were tabulated. The anomalies were transferred to 1:250 000 scale maps which are included in this report. The geological setting of the anomalies has been studied. Ground follow-up work has been recommended for anomalies which occur over mineralized pans and drainage channels, and the Lower Beaufort Stage. Other anomalies which occur over the Ecca Series, the Middle Beaufort Stage, the Upper Beaufort Stage and the Stormberg Series have also been recommended for ground investigation

  1. Radiometric measurement techniques in metallurgy and foundry technology

    1990-01-01

    The contributions contain informations concerning the present state and development of radiometric measurement techniques in metallurgy and foundry technology as well as their application to the solution of various problems. The development of isotope techniques is briefly described. Major applications of radiometric equipment in industrial measurement are presented together with the use of isotopes to monitor processes of industrial production. This is followed by a short description of numerous laboratory-scale applications. Another contribution deals with fundamental problems and methods of moisture measurement by neutrons. A complex moisture/density measurement device the practical applicability of which has been tested is described here. Possibilities for clay determination in used-up moulding materials are discussed in a further contribution. The clay content can be determined by real-time radiometric density measurement so that the necessary moisture or addition of fresh sand can be controlled. (orig.) With 20 figs., 9 tabs., 178 refs [de

  2. Applications of high resolution airborne magnetic and radiometric data in the Barberton Greenstone Belt of South Africa

    Moore, C.

    1994-01-01

    We investigated the data obtained from a geophysical survey of the Greenstone Belt in the Barberton mountain land in the Transvaal, South Africa. A geological map is derived from the airborne magnetic and radiometric survey which differs significantly from the published geological map, particularly in the eastern are of the survey. There is no evidence contained within the geological data to suggest that the Greenstone Belt extends to a depth greater that 3 kilometers. The major geological constituents of the Barberton mountain land displays distinctive and diagnostic radiometric signatures, enabling accurate lithologic discrimination. 63 refs

  3. Radiometric densimeter for measuring and automatic control of liquid density

    Wajs, J.

    1982-01-01

    A performance rule of the radiometric densimeter produced by ''POLON ''Works is presented. A simplified analysis of the correction of density indication changes due to liquid temperature variations is described. A method of replacing the measuring pipe carrying the liquid being measured by suitable standards is given. The method is for automatic systems control. (A.S.)

  4. Analysis of airborne radiometric data. Volume 2. Description, listing, and operating instructions for the code DELPHI/MAZAS. Final report

    Sperling, M.; Shreve, D.C.

    1978-01-01

    The computer code DELPHI is an interactive English language command system for the analysis of airborne radiometric data. The code includes modules for data reduction, data simulation, time filtering, data adjustment and graphical presentation of the results. DELPHI is implemented in FORTRAN on a DEC-10 computer. This volume gives a brief set of operations instructions, samples of the output obtained from hard copies of the display on a Tektronix terminal and finally a listing of the code

  5. Analysis of airborne radiometric data. Volume 2. Description, listing, and operating instructions for the code DELPHI/MAZAS. Final report

    Sperling, M.; Shreve, D.C.

    1978-12-01

    The computer code DELPHI is an interactive English language command system for the analysis of airborne radiometric data. The code includes modules for data reduction, data simulation, time filtering, data adjustment and graphical presentation of the results. DELPHI is implemented in FORTRAN on a DEC-10 computer. This volume gives a brief set of operations instructions, samples of the output obtained from hard copies of the display on a Tektronix terminal and finally a listing of the code.

  6. Pukaki 1-01 : initial luminescence dating and radiometric measurements

    Rieser, U.

    2001-01-01

    Core from Pukaki 1-01 was sampled for luminescence dating and radiometric measurements on 14 March 2001 in the dark room laboratory at Victoria University. Seven samples were taken to get an overview of the crater history, and laboratory work was completed in August 2001. (author). 2 figs., 3 tabs

  7. Radiometric measurement of ceramic material moisture

    Kominek, A.; Sojka, J.; Votava, P.

    1975-01-01

    Water content measurement using a neutron moisture meter has a long tradition in the CSSR. The method of water content determination using neutron and gamma radiation was developed by the Research Institute of Building Materials in Brno for a number of materials, as e.g. coke, brown coal semi-coke, anthracite, glass sand, dolomite, soda, gravel, aggregates, cement sludge, slag, brick clay, intermediate products of the ceramics industry, refractory building materials, etc. The water content measurement of ceramic materials for the manufacture of wall tiles was performed in a special equipment by detection of the slowed-down neutrons with an accuracy of +-0.6% water (within the range from 5 to 11%) and of materials for the manufacture of floor tiles by means of neutron and gamma radiation with an accuracy of +-0.4% water (within the range from 5 to 8%). (author)

  8. The Radiometric Measurement Quantity for SAR Images

    Döring, Björn J.; Schwerdt, Marco

    2013-01-01

    A Synthetic Aperture Radar (SAR) system measures among other quantities the terrain radar reflectivity. After image calibration, the pixel intensities are commonly expressed in terms of radar cross sections (for point targets) or as backscatter coefficients (for distributed targets), which are directly related. This paper argues that pixel intensities are not generally proportional to radar cross section or derived physical quantities. The paper further proposes to replace the inaccurate term...

  9. High speed radiometric measurements of IED detonation fireballs

    Spidell, Matthew T.; Gordon, J. Motos; Pitz, Jeremey; Gross, Kevin C.; Perram, Glen P.

    2010-04-01

    Continuum emission is predominant in fireball spectral phenomena and in some demonstrated cases, fine detail in the temporal evolution of infrared spectral emissions can be used to estimate size and chemical composition of the device. Recent work indicates that a few narrow radiometric bands may reveal forensic information needed for the explosive discrimination and classification problem, representing an essential step in moving from "laboratory" measurements to a rugged, fieldable system. To explore phenomena not observable in previous experiments, a high speed (10μs resolution) radiometer with four channels spanning the infrared spectrum observed the detonation of nine home made explosive (HME) devices in the 0.98) using blast model functional forms, suggesting that energy release could be estimated from single-pixel radiometric detectors. Comparison of radiometer-derived fireball size with FLIR infrared imagery indicate the Planckian intensity size estimates are about a factor of two smaller than the physical extent of the fireball.

  10. Construction of radioelement and dose rate baseline maps by combining ground and airborne radiometric data

    Rybach, L.; Medici, F.; Schwarz, G.F.

    1997-01-01

    For emergency situations like nuclear accidents, lost isotopic sources, debris of reactor-powered satellites etc. well-documented baseline information is indispensable. Maps of cosmic, terrestrial natural and artificial radiation can be constructed by assembling different datasets such as ground and airborne gamma spectrometry, direct dose rate measurements, and soil/rock samples. The in situ measurements were calibrated using the soil samples taken at/around the field measurement sites, the airborne measurements by a combination of in situ, and soil/rock sample data. The radioelement concentrations (Bq/kg) were in turn converted to dose-rate (nSv/h). First, the cosmic radiation map was constructed from a digital terrain model, averaging topographic heights within cells of 2 km X 2 km size. For the terrestrial radiation a total of 1615 ground data points were available, in addition to the airborne data. The artificial radiation map (Chernobyl and earlier fallout) has the smallest data base (184 data points from airborne and ground measurements). The dose rate map was constructed by summing up the above-mentioned contributions. It relies on a data base which corresponds to a density of about 1 point per 25 km 2 . The cosmic radiation map shows elevated dose rates in the high parts of the Swiss Alps. The cosmic dose rate ranges from 40 to 190 nSv/h, depending on altitude. The terrestrial dose rate maps show general agreement with lithology: elevated dose rates (100 to 200 nSv/h) characterize the Central Massifs of the Alps where crystalline rocks give a maximum of 370 nSv/h, whereas the sedimentary northern Alpine Foreland (Jura, Molasse basin) shows consistently lower dose rates (40-100 nSv/h). The artificial radiation map has its maximum value in the southern part of Switzerland (90 nSv/h). The map of total dose rate exhibits values from 55 to 570 nSv/h. These values are considerably higher than reported in the Radiation Atlas (''Natural Sources of Ionising

  11. A new radiometric unit of measure to characterize SWIR illumination

    Richards, A.; Hübner, M.

    2017-05-01

    We propose a new radiometric unit of measure we call the `swux' to unambiguously characterize scene illumination in the SWIR spectral band between 0.8μm-1.8μm, where most of the ever-increasing numbers of deployed SWIR cameras (based on standard InGaAs focal plane arrays) are sensitive. Both military and surveillance applications in the SWIR currently suffer from a lack of a standardized SWIR radiometric unit of measure that can be used to definitively compare or predict SWIR camera performance with respect to SNR and range metrics. We propose a unit comparable to the photometric illuminance lux unit; see Ref. [1]. The lack of a SWIR radiometric unit becomes even more critical if one uses lux levels to describe SWIR sensor performance at twilight or even low light condition, since in clear, no-moon conditions in rural areas, the naturally-occurring SWIR radiation from nightglow produces a much higher irradiance than visible starlight. Thus, even well-intentioned efforts to characterize a test site's ambient illumination levels in the SWIR band may fail based on photometric instruments that only measure visible light. A study of this by one of the authors in Ref. [2] showed that the correspondence between lux values and total SWIR irradiance in typical illumination conditions can vary by more than two orders of magnitude, depending on the spectrum of the ambient background. In analogy to the photometric lux definition, we propose the SWIR irradiance equivalent `swux' level, derived by integration over the scene SWIR spectral irradiance weighted by a spectral sensitivity function S(λ), a SWIR analog of the V(λ) photopic response function.

  12. Radioactive Contamination Estimation from micro-copters or helicopter Airborne survey: Simulation and real measurements

    Halevy, I.; Ghelman, M.; Yehuda-Zada, Y.; Manor, A.; Dadon, S.; Sharon, A.; Yaar, I.

    2014-01-01

    One of the main advantages of acquiring aero-radiometric measurements lies in the high collection rate of data over large areas and rough terrain. Typical aero-radiometric system records and saves gamma ray spectrum, correlated with the GPS derived location information in regular time intervals of one to two seconds. Such data can be used to locate radiation anomalies on the ground, map ground contamination or track a radioactive airborne plume. Acquiring spectral data of this type allows separation of natural radioactivity from that of man-made sources and identification of specific isotopes, natural or man-made

  13. Radioactive Contamination Estimation from Micro-Copters or Helicopter Airborne Survey: Simulation and Real Measurements

    Halevy, I.; Ghelman, M.; Yehuda-Zada, Y.; Manor, A.; Sharon, A.; Yaar, I.

    2014-01-01

    One of the main advantages of acquiring aero-radiometric measurements lies in the high collection rate of data over large areas and rough terrain. Typical aero-radiometric system records and saves gamma ray spectrum, correlated with the GPS derived location information in regular time intervals of one to two seconds. Such data can be used to locate radiation anomalies on the ground, map ground contamination or track a radioactive airborne plume. Acquiring spectral data of this type allows separation of natural radioactivity from that of man-made sources and identification of specific isotopes, natural or man-made

  14. Development of instrumentation for airborne radiometric surveys in the Atomic Minerals Division: Past, present, and future

    Sreehari, R.

    1993-01-01

    A high-sensitivity airborne gamma-ray spectrometric and magnetic survey system, using Na(Tl) detector volume of 50,000 cc for 4π and 4195 cc for 2π geometry applications, was designed, developed, and fabricated in 1978 and was flown for airborne surveys in various parts of India for over a decade. A compact complementary metal-oxide-semiconductor (CMOS) logic circuit based high-sensitivity airborne gamma-ray spectrometric and magnetic survey system with high noise-immunity using Na(Tl) detector volume of 50,000 cc for 4π and 12,500 cc for 2π geometry applications was developed and interfaced to an Inertial Navigation System in 1988. The system currently in use was flown extensively for airborne surveys in various parts of India for the Atomic Minerals Division, Oil and Natural Gas Commission, and Nuclear Power Corporation. The design aspects of the present system have been discussed. A microprocessor based DDAS and multichannel analysers, having on-line micro terminal and on-line corrections for Compton scatter, and background radiation to obtain corrected analog profiles for the spectrometric data, are currently under development. The design aspects of these units are described and evaluated for future high-sensitivity airborne gamma-ray spectrometric surveys with Nal(Tl) detector volumes similar to those of the present system. (author). 8 refs., 3 figs., 1 tab

  15. A feasibility study of geogenic indoor radon mapping from airborne radiometric survey in northern Thailand

    Wattananikorn, K. [Department of Physics, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)], E-mail: kittic@science.cmu.ac.th; Emharuthai, S. [Department of Physics, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wanaphongse, P. [Office of Atoms for Peace, Bangkok (Thailand)

    2008-01-15

    Experiments were carried out in seven test sites on three Quaternary alluvial and terrace deposit basins of northern Thailand, to test the possibility of using airborne equivalent uranium to predict geogenic indoor radon values of the region. The methodology was based on the correlation among soil gas permeability, soil radon concentration and indoor radon, as well as a relationship between soil radon and airborne uranium values. The methodology established works rather well when tested in areas of known indoor radon. Based on the predicted values that were obtained from this method, indoor radon in most areas of alluvial and terrace deposit basins of northern Thailand is less than 44Bq/m{sup 3}. There is no area in these basins where predicted indoor radon exceeds 74Bq/m{sup 3}.

  16. Study and characterization of porous germanium for radiometric measurements

    Akkari, E.; Benachour, Z.; Touayar, O.; Benbrahim, J. [Activites de Recherche, Metrologie des Rayonnements, Institut National des Sciences Appliquees et de Technologie, INSAT, Tunis (Tunisia); Aouida, S.; Bessais, B. [Laboratoire de Nanomateriaux et des Systemes de l' Energie, LaNSE, Centre de Recherche et des Technologies de l' Energie, CRTEn, Hammam-Lif (Tunisia)

    2009-07-15

    The aim of this article is to study and realize a new detector based on a porous germanium (pGe) photodiode to be used as a standard for radiometric measurement in the wavelength region between 800 nm and 1700 nm. We present the development and characterization of a porous structure realized on a single-crystal substrate of p-type germanium (Ga doped) and of crystallographic orientation (100). The obtained structure allows, on the one hand, to trap the incident radiation, and on the other hand, to minimize the fluctuations of the front-face reflection coefficient of the photodiode. The first studies thus made show that it is possible to optimize, respectively, the electrical current density and the electrochemical operation time necessary for obtaining exploitable porous structures. The obtained results show that for 50 mA/cm{sup 2} and 5 min as operational parameters, we obtain a textured aspect of the porous samples that present a pyramidal form. The reflectivity study of the front surface shows a constant value of around 38% in a spectral range between 800 nm and 1700 nm approximately. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. RapidEye constellation relative radiometric accuracy measurement using lunar images

    Steyn, Joe; Tyc, George; Beckett, Keith; Hashida, Yoshi

    2009-09-01

    The RapidEye constellation includes five identical satellites in Low Earth Orbit (LEO). Each satellite has a 5-band (blue, green, red, red-edge and near infrared (NIR)) multispectral imager at 6.5m GSD. A three-axes attitude control system allows pointing the imager of each satellite at the Moon during lunations. It is therefore possible to image the Moon from near identical viewing geometry within a span of 80 minutes with each one of the imagers. Comparing the radiometrically corrected images obtained from each band and each satellite allows a near instantaneous relative radiometric accuracy measurement and determination of relative gain changes between the five imagers. A more traditional terrestrial vicarious radiometric calibration program has also been completed by MDA on RapidEye. The two components of this program provide for spatial radiometric calibration ensuring that detector-to-detector response remains flat, while a temporal radiometric calibration approach has accumulated images of specific dry dessert calibration sites. These images are used to measure the constellation relative radiometric response and make on-ground gain and offset adjustments in order to maintain the relative accuracy of the constellation within +/-2.5%. A quantitative comparison between the gain changes measured by the lunar method and the terrestrial temporal radiometric calibration method is performed and will be presented.

  18. A new radiometric instrument designed to measure the parameters of bituminous coal on transport belts

    Kubicek, P.

    1993-01-01

    A new radiometric instrument developed in Czechoslovakia, for the measurement of ash content of bituminous coal, and for the determination of approximate values of moisture and weight is described. (Author)

  19. An Assessment of Polynomial Regression Techniques for the Relative Radiometric Normalization (RRN of High-Resolution Multi-Temporal Airborne Thermal Infrared (TIR Imagery

    Mir Mustafizur Rahman

    2014-11-01

    Full Text Available Thermal Infrared (TIR remote sensing images of urban environments are increasingly available from airborne and satellite platforms. However, limited access to high-spatial resolution (H-res: ~1 m TIR satellite images requires the use of TIR airborne sensors for mapping large complex urban surfaces, especially at micro-scales. A critical limitation of such H-res mapping is the need to acquire a large scene composed of multiple flight lines and mosaic them together. This results in the same scene components (e.g., roads, buildings, green space and water exhibiting different temperatures in different flight lines. To mitigate these effects, linear relative radiometric normalization (RRN techniques are often applied. However, the Earth’s surface is composed of features whose thermal behaviour is characterized by complexity and non-linearity. Therefore, we hypothesize that non-linear RRN techniques should demonstrate increased radiometric agreement over similar linear techniques. To test this hypothesis, this paper evaluates four (linear and non-linear RRN techniques, including: (i histogram matching (HM; (ii pseudo-invariant feature-based polynomial regression (PIF_Poly; (iii no-change stratified random sample-based linear regression (NCSRS_Lin; and (iv no-change stratified random sample-based polynomial regression (NCSRS_Poly; two of which (ii and iv are newly proposed non-linear techniques. When applied over two adjacent flight lines (~70 km2 of TABI-1800 airborne data, visual and statistical results show that both new non-linear techniques improved radiometric agreement over the previously evaluated linear techniques, with the new fully-automated method, NCSRS-based polynomial regression, providing the highest improvement in radiometric agreement between the master and the slave images, at ~56%. This is ~5% higher than the best previously evaluated linear technique (NCSRS-based linear regression.

  20. Solar Tower Experiments for Radiometric Calibration and Validation of Infrared Imaging Assets and Analysis Tools for Entry Aero-Heating Measurements

    Splinter, Scott C.; Daryabeigi, Kamran; Horvath, Thomas J.; Mercer, David C.; Ghanbari, Cheryl M.; Ross, Martin N.; Tietjen, Alan; Schwartz, Richard J.

    2008-01-01

    The NASA Engineering and Safety Center sponsored Hypersonic Thermodynamic Infrared Measurements assessment team has a task to perform radiometric calibration and validation of land-based and airborne infrared imaging assets and tools for remote thermographic imaging. The IR assets and tools will be used for thermographic imaging of the Space Shuttle Orbiter during entry aero-heating to provide flight boundary layer transition thermography data that could be utilized for calibration and validation of empirical and theoretical aero-heating tools. A series of tests at the Sandia National Laboratories National Solar Thermal Test Facility were designed for this task where reflected solar radiation from a field of heliostats was used to heat a 4 foot by 4 foot test panel consisting of LI 900 ceramic tiles located on top of the 200 foot tall Solar Tower. The test panel provided an Orbiter-like entry temperature for the purposes of radiometric calibration and validation. The Solar Tower provided an ideal test bed for this series of radiometric calibration and validation tests because it had the potential to rapidly heat the large test panel to spatially uniform and non-uniform elevated temperatures. Also, the unsheltered-open-air environment of the Solar Tower was conducive to obtaining unobstructed radiometric data by land-based and airborne IR imaging assets. Various thermocouples installed on the test panel and an infrared imager located in close proximity to the test panel were used to obtain surface temperature measurements for evaluation and calibration of the radiometric data from the infrared imaging assets. The overall test environment, test article, test approach, and typical test results are discussed.

  1. Virtual and remote experiments for radiometric and photometric measurements

    Thoms, L-J; Girwidz, R

    2017-01-01

    The analysis of spectra is fundamental to our modern understanding of wave optics and colour perception. Since spectrometers are expensive, and accurate calibration is necessary to achieve high quality spectra, we developed a remote lab on optical spectrometry. With this tool, students can carry out real experiments over the Internet. In this article the pros and cons of remote labs, the physical background of optical spectrometry, and the development and use of a radiometric remote lab for higher education are discussed. The remote lab is freely accessible to everyone at http://virtualremotelab.net. (paper)

  2. Virtual and remote experiments for radiometric and photometric measurements

    Thoms, L.-J.; Girwidz, R.

    2017-09-01

    The analysis of spectra is fundamental to our modern understanding of wave optics and colour perception. Since spectrometers are expensive, and accurate calibration is necessary to achieve high quality spectra, we developed a remote lab on optical spectrometry. With this tool, students can carry out real experiments over the Internet. In this article the pros and cons of remote labs, the physical background of optical spectrometry, and the development and use of a radiometric remote lab for higher education are discussed. The remote lab is freely accessible to everyone at http://virtualremotelab.net.

  3. Microwave radiometric measurements of soil moisture in Italy

    G. Macelloni

    2003-01-01

    Full Text Available Within the framework of the MAP and RAPHAEL projects, airborne experimental campaigns were carried out by the IFAC group in 1999 and 2000, using a multifrequency microwave radiometer at L, C and X bands (1.4, 6.8 and 10 GHz. The aim of the experiments was to collect soil moisture and vegetation biomass information on agricultural areas to give reliable inputs to the hydrological models. It is well known that microwave emission from soil, mainly at L-band (1.4 GHz, is very well correlated to its moisture content. Two experimental areas in Italy were selected for this project: one was the Toce Valley, Domodossola, in 1999, and the other, the agricultural area of Cerbaia, close to Florence, where flights were performed in 2000. Measurements were carried out on bare soils, corn and wheat fields in different growth stages and on meadows. Ground data of soil moisture (SMC were collected by other research teams involved in the experiments. From the analysis of the data sets, it has been confirmed that L-band is well related to the SMC of a rather deep soil layer, whereas C-band is sensitive to the surface SMC and is more affected by the presence of surface roughness and vegetation, especially at high incidence angles. An algorithm for the retrieval of soil moisture, based on the sensitivity to moisture of the brightness temperature at C-band, has been tested using the collected data set. The results of the algorithm, which is able to correct for the effect of vegetation by means of the polarisation index at X-band, have been compared with soil moisture data measured on the ground. Finally, the sensitivity of emission at different frequencies to the soil moisture profile was investigated. Experimental data sets were interpreted by using the Integral Equation Model (IEM and the outputs of the model were used to train an artificial neural network to reproduce the soil moisture content at different depths. Keywords: microwave radiometry, soil moisture

  4. Airborne laser altimeter measurements of landscape topography

    Ritchie, J.C.

    1995-01-01

    Measurements of topography can provide a wealth of information on landscape properties for managing hydrologic and geologic systems and conserving natural and agricultural resources. This article discusses the application of an airborne laser altimeter to measure topography and other landscape surface properties. The airborne laser altimeter makes 4000 measurements per second with a vertical recording resolution of 5 cm. Data are collected digitally with a personal computer. A video camera, borehole sighted with the laser, records an image for locating flight lines. GPS data are used to locate flight line positions on the landscape. Laser data were used to measure vegetation canopy topography, height, cover, and distribution and to measure microtopography of the land surface and gullies with depths of 15–20 cm. Macrotopography of landscape profiles for segments up to 4 km were in agreement with available topographic maps but provided more detail. Larger gullies with and without vegetation, and stream channel cross sections and their associated floodplains have also been measured and reported in other publications. Landscape segments for any length could be measured for either micro- or macrotopography. Airborne laser altimeter measurements of landscape profiles can provide detailed information on landscape properties or specific needs that will allow better decisions on the design and location of structures (i.e., roads, pipe, and power lines) and for improving the management and conservation of natural and agricultural landscapes. (author)

  5. Basing of principles and methods of operation of radiometric control and measurement systems

    Onishchenko, A.M.

    1995-01-01

    Six basic stages of optimization of radiometric systems, methods of defining the preset components of total error and the choice of principles and methods of measurement are described in succession. The possibility of simultaneous optimization of several stages, turning back to the already passed stages, is shown. It is suggested that components of the total error should be preset as identical ones for methodical, instrument, occasional and representativity errors and the greatest of the components should be decreased first of all. Comparative table for 64 radiometric methods of measurement by 11 indices of the methods quality is presented. 2 refs., 1 tab

  6. Airborne Atmospheric Aerosol Measurement System

    Ahn, K.; Park, Y.; Eun, H.; Lee, H.

    2015-12-01

    It is important to understand the atmospheric aerosols compositions and size distributions since they greatly affect the environment and human health. Particles in the convection layer have been a great concern in global climate changes. To understand these characteristics satellite, aircraft, and radio sonde measurement methods have usually been used. An aircraft aerosol sampling using a filter and/or impactor was the method commonly used (Jay, 2003). However, the flight speed particle sampling had some technical limitations (Hermann, 2001). Moreover, the flight legal limit, altitude, prohibited airspace, flight time, and cost was another demerit. To overcome some of these restrictions, Tethered Balloon Package System (T.B.P.S.) and Recoverable Sonde System(R.S.S.) were developed with a very light optical particle counter (OPC), impactor, and condensation particle counter (CPC). Not only does it collect and measure atmospheric aerosols depending on altitudes, but it also monitors the atmospheric conditions, temperature, humidity, wind velocity, pressure, GPS data, during the measurement (Eun, 2013). In this research, atmospheric aerosol measurement using T.B.P.S. in Ansan area is performed and the measurement results will be presented. The system can also be mounted to an unmanned aerial vehicle (UAV) and create an aerial particle concentration map. Finally, we will present measurement data using Tethered Balloon Package System (T.B.P.S.) and R.S.S (Recoverable Sonde System).

  7. Investigation of Pre- and Post-Flight Radiometric Calibration Uncertainties from Surface Based Measurements

    Heath, D.F.; Wei, Z.Y.; Ahman, Z.

    1997-06-01

    A new technique has been developed for inferring column ozone amounts and aerosol optical depths from zenith sky observations. A new radiometric calibration technique for large aperture remote sensing instruments observing the earth through space has been validated which subsequently increased the accuracy of remote sensing measurements of ozone and vertical profiles using measurements of back-scattered ultraviolet solar radiation.

  8. Initial Radiometric Characteristics of KOMPSAT-3A Multispectral Imagery Using the 6S Radiative Transfer Model, Well-Known Radiometric Tarps, and MFRSR Measurements

    Jong-Min Yeom

    2017-02-01

    Full Text Available On-orbit radiometric characterization of the multispectral (MS imagery of the Korea Aerospace Research Institute (KARI’s Korea Multi-Purpose Satellite-3A (KOMPSAT-3A, which was launched on 25 March 2015, was conducted to provide quantitative radiometric information about KOMPSAT-3A. During the in-orbit test (IOT, vicarious radiometric calibration of KOMPSAT-3A was performed using the Second Simulation of a Satellite Signal in the Solar Spectrum (6S radiative transfer model. The characteristics of radiometric tarps, the atmospheric optical depth from multi-filter rotating shadowband radiometer (MFRSR measurements, and sun–sensor–geometry were carefully considered, in order to calculate the exact top of atmosphere (TOA radiance received by KOMPSAT-3A MS bands. In addition, the bidirectional reflectance distribution function (BRDF behaviors of the radiometric tarps were measured in the laboratory with a two-dimensional hyperspectral gonioradiometer, to compensate for the geometry discrepancy between the satellite and the ASD FieldSpec® 3 spectroradiometer. The match-up datasets between the TOA radiance and the digital number (DN from KOMPSAT-3A were used to determine DN-to-radiance conversion factors, based on linear least squares fitting for two field campaigns. The final results showed that the R2 values between the observed and simulated radiances for the blue, green, red, and near-infrared (NIR bands, are greater than 0.998. An approximate error budget analysis for the vicarious calibration of KOMPSAT-3A showed an error of less than 6.8%. When applying the laboratory-based BRDF correction to the case of higher viewing zenith angle geometry, the gain ratio was improved, particularly for the blue (1.3% and green (1.2% bands, which exhibit high sensitivity to the BRDF of radiometric tarps during the backward-scattering phase. The calculated gain ratio between the first and second campaigns showed a less than 5% discrepancy, indicating that

  9. Airborne radiometric anomalies caused by late kinematic granite rocks in the Molson Lake-Red Sucker Lake area, east-central Manitoba

    Weber, W.; Schledewitz, D.C.P.; Soonawala, N.M.

    1982-01-01

    Geological mapping with simultaneous ground gamma ray spectrometer surveys in an area with a chain of airborne radiometric anomalies of greater than 2 ppm eU indicate uranium enrichment in late kinematic pink leucogranitic rocks including granites, alaskites, and syenites which form dykes, stocks and small plutons in a batholithic tonalite - granodiorite complex. Field geolocial evidence suggests that the potassium-rich rocks were formed by hydrothermal solutions and that at least some of them are metasomatic replacement bodies. Results of geophysical grid survey over a pronounced anomaly indicate that it is caused by a significant volume of leucogranitic rocks with an unusually high background concentration of uranium averaging 25 ppm eU. The uranium seems to be associated with hematite which coats mineral grains and fills small fractures

  10. Analysis of airborne radiometric data. Volume 1. Evaluation of the DELPHI/MAZAS computer code. Final report

    Sperling, M.; Shreve, D.C.; Reed, J.H.

    1978-01-01

    Testing and evaluation of the code MAZAS/DELPHI led to the following conclusions: its precision is better than the Window method for the analysis of uranium, comparable for the analysis of potassium, and worse for the analysis of thorium. Its accuracy of MAZAS is consistently better than the Window method when used on simulated data. The accuracy of the average values of the individual gamma-ray intensities obtained with MAZAS is good over the entire energy spectrum for the uranium and thorium spectra. The precision of the intensities of the low energy lines is poor unless 15 to 20 s integration times are used. Results of the analysis of actual flight data for potassium and thorium are very similar for MAZAS and the Window method. Results for uranium using MAZAS and the Window method appear to be different. MAZAS, which measures an average of several discrete gamma-ray components, seems to indicate considerably more airborne radon than the Window method. It is suspected that the Window method is measuring a combination of discrete and continuum components and that this is resulting in analyses that are inconsistent with MAZAS. The DELPHI time filter appears to work exceedingly well on simulated data. The accuracy of the method on actual flight data is uncertain

  11. Radiometric analyzer

    Arima, S.; Oda, M.; Miyashita, K.; Takada, M.

    1977-01-01

    A radiometric analyzer for measuring the characteristic values of a sample by radiation includes a humer of radiation measuring subsystems having different ratios of sensitivities to the elements of the sample and linearizing circuits having inverse function characteristics of calibration functions which correspond to the radiation measuring subsystems. A weighing adder operates a desirable linear combination of the outputs of the linearizing circuits. Operators for operating between two or more different linear combinations are included

  12. Calibration and Measurement Uncertainty Estimation of Radiometric Data: Preprint

    Habte, A.; Sengupta, M.; Reda, I.; Andreas, A.; Konings, J.

    2014-11-01

    Evaluating the performance of photovoltaic cells, modules, and arrays that form large solar deployments relies on accurate measurements of the available solar resource. Therefore, determining the accuracy of these solar radiation measurements provides a better understanding of investment risks. This paper provides guidelines and recommended procedures for estimating the uncertainty in calibrations and measurements by radiometers using methods that follow the International Bureau of Weights and Measures Guide to the Expression of Uncertainty (GUM). Standardized analysis based on these procedures ensures that the uncertainty quoted is well documented.

  13. An equivalent method of mixed dielectric constant in passive microwave/millimeter radiometric measurement

    Su, Jinlong; Tian, Yan; Hu, Fei; Gui, Liangqi; Cheng, Yayun; Peng, Xiaohui

    2017-10-01

    Dielectric constant is an important role to describe the properties of matter. This paper proposes This paper proposes the concept of mixed dielectric constant(MDC) in passive microwave radiometric measurement. In addition, a MDC inversion method is come up, Ratio of Angle-Polarization Difference(RAPD) is utilized in this method. The MDC of several materials are investigated using RAPD. Brightness temperatures(TBs) which calculated by MDC and original dielectric constant are compared. Random errors are added to the simulation to test the robustness of the algorithm. Keywords: Passive detection, microwave/millimeter, radiometric measurement, ratio of angle-polarization difference (RAPD), mixed dielectric constant (MDC), brightness temperatures, remote sensing, target recognition.

  14. Rain attenuation studies from radiometric and rain DSD measurements at two tropical locations

    Halder, Tuhina; Adhikari, Arpita; Maitra, Animesh

    2018-05-01

    Efficient use of satellite communication in tropical regions demands proper characterization of rain attenuation, particularly, in view of the available popular propagation models which are mostly based on temperate climatic data. Thus rain attenuations at frequencies 22.234, 23.834 and 31.4/30 GHz over two tropical locations Kolkata (22.57°N, 88.36°E, India) and Belem (1.45°S, 48.49° W, Brazil), have been estimated for the year 2010 and 2011, respectively. The estimation has been done utilizing ground-based disdrometer observations and radiometric measurements over Earth-space path. The results show that rain attenuation estimations from radiometric data are reliable only at low rain rates (measurements show good agreement with the ITU-R model, even at high rain rates (upto100 mm/h). Despite having significant variability in terms of drop size distribution (DSD), the attenuation values calculated from DSD data (disdrometer measurements) at Kolkata and Belem differ a little for the rain rates below 30 mm/h. However, the attenuation values, obtained from radiometric measurements at the two places, show significant deviations ranging from 0.54 dB to 3.2 dB up to a rain rate of 30 mm/h, on account of different rain heights, mean atmospheric temperatures and climatology of the two locations.

  15. Airborne geophysical radon hazard mapping

    Walker, P.

    1993-01-01

    Shales containing uranium pose a radon health hazard even when covered by several meters of overburden. Such an alum shale in southern Norway has been mapped with a joint helicopter borne electromagnetic (HEM) and radiometric survey. Results are compared with ground spectrometer, radon emanometer and radon gas measurements in dwellings, and a model to predict radon gas concentrations from the airborne data is developed. Since the shale is conductive, combining the HEM data with the radiometric channel allows the shale to be mapped with greater reliability than if the radiometric channel were used alone. Radiometrically more active areas which do not pose a radon gas hazard can thus be separated from the shales which do. The ground follow-up work consisted of spectrometer and radon emanometer measurements over a uranium anomaly coinciding with a conductor. The correlation between the airborne uranium channel, the ground uranium channel and emanometry is extremely good, indicating that airborne geophysics can, in this case, be used to predict areas having a high radon potential. Contingency tables comparing both radon exhalation and concentration in dwellings with the airborne uranium data show a strong relationship exists between exhalation and the airborne data and while a relationship between concentration and the airborne data is present, but weaker

  16. Far-ir heterodyne radiometric measurements with quasioptical Schottky diode mixers

    Fetterman, H.R.; Tannenwald, P.E.; Clifton, B.J.; Parker, C.D.; Fitzgerald, W.D.; Erickson, N.R.

    1978-01-01

    We have made heterodyne radiometric measurements with GaAs Schottky diode mixers, mounted in a corner-reflector configuration, over the spectral range 170 μm to 1 mm. At 400 μm, system noise temperatures of 9700 K DSB (NEP=1.4 x 10 - 19 W/Hz) and mixer noise temperatures of 5900 K have been achieved. This same quasioptical mixer has also been used to generate 10 - 7 W of tunable radiation suitable for spectroscopic applications

  17. Nondestructive evaluation of reinforced plastics by a radiometric measurement technique

    Entine, Gerald; Afshari, Sia; Verlinden, Matt

    1990-01-01

    The demand for new high-performance plastics has greatly increased with advances in the performance characteristics of sophisticated reinforced engineering resins. However, conventional methods for the evaluation of the glass and filler contents of reinforced plastics are destructive, labor intensive, and time consuming. We have developed a new instrument, to address this problem, which provides for the rapid, accurate, and nondestructive measurement of glass or filler content in reinforced plastics. This instrument utilizes radiation transmission and scattering techniques for analytical measurement of glass, graphite and other fillers used in reinforced plastics. (author)

  18. Image sensors for radiometric measurements in the ocean

    Desa, E.S.; Desa, B.A.E.

    the sensors at a stabilised moderately cool temperature of 15 deg. C and to intelligently control the exposure time of the device, so as to reliably measure flux levels in the range 1 W/m super(2)/nm to 10/6 W/m super(2)/nm commonly encountered in the ocean...

  19. Digital image integration technique of multi-geoscience information dominated by aerial radiometric measurements

    Liu Dechang; Sun Maorong; Zhu Deling; Zhang Jingbo; He Jianguo; Dong Xiuzhen

    1992-02-01

    The geologic metallogenetic environment of uranium at Lian Shan Guan region has been studied by using digital image integration technique of multi-geoscience information with aerial radiometric measurements. It includes the classification of uranium-bearing rock, recognizing patterns of ore-forming and geologic mapping in ore field. Some new tectonic structure was found in this region that gives significant information for further exploring of uranium ore. After multi-parameters screening of aerial radiometric data, patterns recognizing and multi-geoscience information integration analysis, four prospective metallogenetic zones were predicted, and the predication was proved by further geologic survey. Three of the four zones are very encouraging, where ore-forming structures, hydrothermal deposits, wall-rock alteration, primary and secondary uranium ore and rich uranium mineralization are discovered. The department of geologic exploring has decided that these zones will enjoy priority in the examination for further prospecting of uranium ores

  20. Evaluation of human muscle in vivo by potassium radiometric measuring

    Sousa, Wanderson de P.

    2000-01-01

    Potassium is an essential element to the human metabolism and is present in all living cells, mainly in the striated muscular fibers. K-40 is one of the natural potassium isotopes with mass percentage of 0,0118% . This isotope emits beta particle and gamma rays with 1460 keV. The energy of K-40 photon and its uniform distribution within the human body allows its in vivo measurement. The objective of this study is to optimize this technique and evaluate the possibility of its medical application in order to quantify muscle increase during recovering procedures. Subjects of both sexes measured until this moment were divided into two groups. Subjects of Group 1 do not exercise routinely and subjects of Group 2 does. In Group 1 the average potassium mass, muscle mass and potassium concentration were (101±16)g of K, (20±3)kg of muscle and (1,3±0,3)g of K/kg of body mass, respectively, while in Group 2 average values were (125±38)g of K, (25±8)kg of muscle and (1,7±0,2)g of K/kg of body mass. The comparison between average values shows a clear difference, which allows to correlate a higher K mass with routine body activity. The technique has shown enough sensitivity for this application. (author)

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

    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. Fundamentals of gamma-ray measurements and radiometric analyses

    Hochel, R.C.

    1990-01-01

    There are four primary modes of radioactive decay. All can be measured using various types of detectors and are the basis of many analytical techniques and much of what we know about the nucleus and its structure. Alpha particle emission occurs mostly in heavy nuclei of atomic number, Z, greater than 82 like Po, Ra, Th, and U, etc. Beta particles are simply electrons. They are emitted from the nucleus with a distribution of energies ranging from 0--3 MeV. Gamma-rays are photons with energies ranging from a few keV to 10 MeV or more. They usually follow alpha or beta decay, and depending on their energy, can have considerable range in matter. Neutrons are emitted in fission processes and also from a few of the highly excited fission product nuclei. Fission neutrons typically have energies of 1--2 MeV. Like gamma-rays, they have long ranges. The energies involved in nuclear decay processes are much higher than anything encountered in, say, chemical reactions. They are at the very top of the electromagnetic spectrum -- about a million times more energetic than visible light. As a result, these particles always produce ionization, either directly or indirectly, as they pass through matter. It is this ionization which is the basis of all radiation detectors

  3. UV/visible albedos from airborne measurements

    Webb, A.; Kylling, A.; Stromberg, I.

    2003-04-01

    During the INSPECTRO campaign effective surface albedo was measured at UV and visible wavelengths from two airborne platforms, a Cessna light aircraft and a hot air balloon. On board the Cessna was a scanning spectroradiometer measuring from 300 - 500nm at 10nm intervals. The NILU cube, with 6 faces and two UV channels at 312 and 340nm, was suspended beneath the hot air balloon. Flights took place over East Anglia during September, 2002. Balloon flights were made below cloud layers, while the Cessna flew both above and below cloud. The Cessna also flew over Barton Bendish, where surface albedos have been measured for ground truthing of satellite data, and measured the effective albedo at four visible wave- lengths in the centres of the satellite bandpass functions. Results of measurements from the different platforms are compared, and model simulations used to deduce the surface albedo from the effective albedo at altitude, giving, for example, an albedo of 0.02 ± 0.01 at 340nm.

  4. State of the art and trends of radiometric methods for measuring the mass per unit area

    Bernhardt, R.

    1984-01-01

    The determination of the mass per unit area by means of transmission or backscattering methods is one of the traditional radioisotope applications. Microelectronics have essentially contributed to the noticeable progress achieved in the development of radiometric instruments for mass per unit area measurements. The use of microcomputers led to both a reliable solution of the main problem of processing the measured data - the correlation of the mass per unit area value with the detector signal under nonlinear calibration conditions - and a considerable increase in the efficiency of the measuring equipment

  5. An intercomparison of airborne VOC measurements

    Wisthaler, A.; Hansel, A.; Fall, R.

    2002-01-01

    Full text: During the Texas Air Quality Study (TexAQS) 2000 ambient air samples were analyzed on-board the NSF/NCAR ELECTRA research aircraft by two VOC measurement techniques: 1) an in-situ gas chromatograph named TACOH (Tropospheric Airborne Chromatograph for Oxy-hydrocarbons and Hydrocarbons), operated by NOAA' Aeronomy Laboratory, and 2) a chemical ionization mass spectrometer named PTR-MS (Proton-Transfer-Reaction Mass Spectrometer) and operated by the University of Innsbruck. The sample protocols were quite different for the two methods: the TACOH system collected air samples for 15-60 sec (depending upon altitude) every 15 min, the PTR-MS system monitored selected VOCs on a time-shared basis for 2 sec respectively, once every 4-20 sec, depending upon the number of monitored species. Simultaneous measurements of acetaldehyde, isoprene, the sum* of acetone and propanal, the sum* of methyl vinyl ketone and methacrolein (* PTR-MS does not distinguish between isobaric species) and toluene show good agreement despite being performed in the complex and highly polluted Houston air matrix. (author)

  6. High resolution simultaneous measurements of airborne radionuclides

    Abe, T.; Yamaguchi, Y.; Tanaka, K.; Komura, K.

    2006-01-01

    High resolution (2-3 hrs) simultaneous measurements of airborne radionuclides, 212 Pb, 210 Pb and 7 Be, have been performed by using extremely low background Ge detectors at Ogoya Underground Laboratory. We have measured above radionuclides at three monitoring points viz, 1) Low Level Radioactivity Laboratory (LLRL) Kanazawa University, 2) Shishiku Plateau (640 m MSL) located about 8 km from LLRL to investigate vertical difference of activity levels, and 3) Hegura Island (10 m MSL) located about 50 km from Noto Peninsula in the Sea of Japan to evaluate the influences of Asian continent or mainland of Japan on the variation to the activity levels. Variations of short-lived 212 Pb concentration showed noticeable time lags between at LLRL and at Shishiku Plateau. These time lags might be caused by change of height of a planetary boundary layer. On the contrary, variations of long-lived 210 Pb and 7 Be showed simultaneity at three locations because of homogeneity of these concentrations all over the area. (author)

  7. Radiometric probe design for the measurement of heat flux within a solid rocket motor nozzle

    Goldey, Charles L.; Laughlin, William T.; Popper, Leslie A.

    1996-11-01

    Improvements to solid rocket motor (SRM) nozzle designs and material performance is based on the ability to instrument motors during test firings to understand the internal combustion processes and the response of nozzle components to the severe heating environment. Measuring the desired parameters is very difficult because the environment inside of an SRM is extremely severe. Instrumentation can be quickly destroyed if exposed to the internal rocket motor environment. An optical method is under development to quantify the heating of the internal nozzle surface. A radiometric probe designed for measuring the thermal response and material surface recession within a nozzle while simultaneously confining the combustion products has been devised and demonstrated. As part of the probe design, optical fibers lead to calibrated detectors that measure the interior nozzle thermal response. This two color radiometric measurement can be used for a direct determination of the total heat flux impinging on interior nozzle surfaces. This measurement has been demonstrated using a high power CO2 laser to simulate SRM nozzle heating conditions on carbon phenolic and graphite phenolic materials.

  8. Unibert - PC software for radiometric level gauging - the LB440 measuring system

    Mann, H.; Bickert, M.

    2001-01-01

    In almost all industrial branches radiometric measuring systems are being used today for a lot of different tasks. The most common field of this application are level gauging measurements by use of gamma radiation, i.e. for level detection as well as for level gauging over ranges of up to several meters. For our level gauge measuring system LB440 we developed a clearly arranged PC software, which allows starting, measuring and service of the level gauge. Over the RS232-interface the industrial computer can be connected with a Laptop or PC. The software is a supplemental or even a substitute for the operation over the frontpanel. The measuring system can be completely controlled by the Unibert PC-Software, realised by LabVIEW 5.1.1, which offers an interactive graphical user interface. The same functionality as in the ''embedded - software'' is available, completed with some additional functions. (orig.) [de

  9. Preliminary results of radiometric measurements of clear air and cloud brightness (antenna) temperatures at 37GHz

    Arakelyan, A. K.; Hambaryan, A. K.; Arakelyan, A. A.

    2012-05-01

    In this paper the results of polarization measurements of clear air and clouds brightness temperatures at 37GHz are presented. The results were obtained during the measurements carried out in Armenia from the measuring complex built under the framework of ISTC Projects A-872 and A-1524. The measurements were carried out at vertical and horizontal polarizations, under various angles of sensing by Ka-band combined scatterometric-radiometric system (ArtAr-37) developed and built by ECOSERV Remote Observation Centre Co.Ltd. under the framework of the above Projects. In the paper structural and operational features of the utilized system and the whole measuring complex will be considered and discussed as well.

  10. Airborne gravity field Measurements - status and developments

    Olesen, Arne Vestergaard; Forsberg, René

    2016-01-01

    English Abstract:DTU-Space has since 1996 carried out large area airborne surveys over both polar, tropical and temperate regions, especially for geoid determination and global geopotential models. Recently we have started flying two gravimeters (LCR and Chekan-AM or inertial navigation systems) ...

  11. Measuring two-phase and two-component mixtures by radiometric technique

    Mackuliak, D.; Rajniak, I.

    1984-01-01

    The possibility was tried of the application of the radiometric method in measuring steam water content. The experiments were carried out in model conditions where steam was replaced with the two-component mixture of water and air. The beta radiation source was isotope 204 Tl (Esub(max)=0.765 MeV) with an activity of 19.35 MBq. Measurements were carried out within the range of the surface density of the mixture from 0.119 kg.m -2 to 0.130 kg.m -2 . Mixture speed was 5.1 m.s -1 to 7.1 m.s -1 . The observed dependence of relative pulse frequency on the specific water content in the mixture was approximated by a linear regression. (B.S.)

  12. Measuring instrument for the determination of dust concentrations. [air filter with. beta. radiometric gage

    Dresia, H; Spohr, F

    1975-05-22

    The measuring instrument enables a continuous determination of the dust concentration or total dust content in gases on the basis of the radiometric mass determination of dusts. The partial current method is employed, with the gas fetched through a filter cell with a topped intake by a suction pump. A filter band to take up the dust deposit is continuously driven through the filter cell. The filter point and the measuring point with a ..beta..-radionuclide and a detector are both inside the filter cell. The filter cell is sealed all around, at the entrance and exit of the filter band. The band itself acts as a seal. The filter band also has borders strengthened with, e.g., plastic strips which engage the drive. The widths of the slits are adjustable in height.

  13. Measurement of particle emission in automobil exhaust - application of continuous radiometric aerosol measurement to the emission of diesel engines

    Krasenbrink, A.; Georgi, B.

    1989-01-01

    The well-known method of measuring continuously dust by β-absorption is transferred to the problem of particle emission in automobile exhaust. With two similar dust-monitors FH62 having different sampling air flow rates and two low-pressure impactors the reliability of radiometric mass determination was verified. First static experiments with diesel soot showed the necessity of a dilution system, a new mass calibration with regard to the changed β-absorptivity and a quicker calculation of concentration for realtime measurements. (orig.) [de

  14. Measuring canopy structure with an airborne laser altimeter

    Ritchie, J.C.; Evans, D.L.; Jacobs, D.; Everitt, J.H.; Weltz, M.A.

    1993-01-01

    Quantification of vegetation patterns and properties is needed to determine their role on the landscape and to develop management plans to conserve our natural resources. Quantifying vegetation patterns from the ground, or by using aerial photography or satellite imagery is difficult, time consuming, and often expensive. Digital data from an airborne laser altimeter offer an alternative method to quantify selected vegetation properties and patterns of forest and range vegetation. Airborne laser data found canopy heights varied from 2 to 6 m within even-aged pine forests. Maximum canopy heights measured with the laser altimeter were significantly correlated to measurements made with ground-based methods. Canopy shape could be used to distinguish deciduous and evergreen trees. In rangeland areas, vegetation heights, spatial patterns, and canopy cover measured with the laser altimeter were significantly related with field measurements. These studies demonstrate the potential of airborne laser data to measure canopy structure and properties for large areas quickly and quantitatively

  15. Development and application of a radiometric method of measurement (Heger probe) for characterizing clastic rock strata in exposures

    Koch, G.

    1984-01-01

    The radiometric image of a stratigraphic exposure profile was to be logged. The method of measurement was tested on clastic sediments of the Tertiary (Saudi Arabia) and Bunter (Northern Germany). The well-tried scintillometer technique was supplemented by modern technological means supplied by a prospecting company (Gewerkschaft Brunhilde). The probe applied was specifically developped for stratigraphic purposes. (orig./HP) [de

  16. Digital Airborne Photogrammetry—A New Tool for Quantitative Remote Sensing?—A State-of-the-Art Review On Radiometric Aspects of Digital Photogrammetric Images

    Nikolaj Veje

    2009-09-01

    Full Text Available The transition from film imaging to digital imaging in photogrammetric data capture is opening interesting possibilities for photogrammetric processes. A great advantage of digital sensors is their radiometric potential. This article presents a state-of-the-art review on the radiometric aspects of digital photogrammetric images. The analysis is based on a literature research and a questionnaire submitted to various interest groups related to the photogrammetric process. An important contribution to this paper is a characterization of the photogrammetric image acquisition and image product generation systems. The questionnaire revealed many weaknesses in current processes, but the future prospects of radiometrically quantitative photogrammetry are promising.

  17. On the radiometric measurement of the density distribution occuring at the horizontal hydraulic transport of solid matter

    Goedde, E.; Weber, M.

    1977-01-01

    In order to estimate the phenomena of the flow in horizontal hydraulic transport of solid matter, measuring the density structure along the vertical pipe diameter is of vital interest for basic investigations. The measurement technology in mixed flows of solid matter and water is very difficult and therefore only few publications on characteristic flow profiles in horizontal pipes are known. In a research programme advanced by the Deutsche Forschungsgemeinschaft investigations were made on the possibility to measure the density profile by means of plain measuring equipment based upon radiometrics. In this paper a combination of a nuclear radiometric polar and parallel scanning method is shown to be suitable for this kind of measurements. (orig.) [de

  18. A W-Band Radiometer with the Offset Parabolic Antenna for Radiometric Measurements

    Li Wu

    2016-01-01

    Full Text Available This paper deals with the development of a W-band noise-adding radiometer which combines the millimeter-wave (MMW radiometric measurements with a high-resolution imager. The offset parabolic antenna is presented to achieve an accurate measurement and a high resolution. To reduce the cross-polarization level of the antenna, a multimode feed horn with a multistep structure is proposed to match the focal region fields of the reflector. It has advantages over the corrugated horns in lower mass and easier manufacturing. In addition, due to an unavoidable settling time for the noise-adding radiometer output signal passing through the low-pass filter, a theoretical criterion for the optimum duty cycle determination to reject extraneous contributions from the transient is proposed in this paper. The appropriate duty cycle threshold is 0.33 for the developed W-band radiometer. Also, a geometric correction method is presented to correct the obtained passive image suffering from a distortion for a better image interpretation. Preliminary experimental results are given to illustrate and verify the presented techniques.

  19. Pulsed Airborne Lidar Measurements of C02 Column Absorption

    Abshire, James B.; Riris, Haris; Allan, Graham R.; Weaver, Clark J.; Mao, Jianping; Sun, Xiaoli; Hasselbrack, William E.; Rodriquez, Michael; Browell, Edward V.

    2011-01-01

    We report on airborne lidar measurements of atmospheric CO2 column density for an approach being developed as a candidate for NASA's ASCENDS mission. It uses a pulsed dual-wavelength lidar measurement based on the integrated path differential absorption (IPDA) technique. We demonstrated the approach using the CO2 measurement from aircraft in July and August 2009 over four locations. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. The 2009 measurements have been analyzed in detail and the results show approx.1 ppm random errors for 8-10 km altitudes and approx.30 sec averaging times. Airborne measurements were also made in 2010 with stronger signals and initial analysis shows approx. 0.3 ppm random errors for 80 sec averaging times for measurements at altitudes> 6 km.

  20. Representativeness of the IAGOS airborne measurements in the lower troposphere

    Petetin, H.; Jeoffrion, M.; Sauvage, B.; Athier, G.; Blot, R.; Boulanger, D.; Clark, H.; Cousin, J.-M.; Gheusi, F.; Nedelec, P.; Steinbacher, M.; Thouret, V.

    2018-01-01

    In the framework of the In Service Aircraft for Global Observing System (IAGOS) program, airborne in-situ O3 and CO measurements are performed routinely using in-service aircraft, providing vertical profiles from the surface to about 10–12 km. Due to the specificity of IAGOS measurements (measurements around busy international airports), uncertainties exist on their representativeness in the lower troposphere as they may be impacted by emissions related to airport activities and/or other air...

  1. A STUDY ON THE EFFECTS OF VIEWING ANGLE VARIATION IN SUGARCANE RADIOMETRIC MEASURES

    Érika Akemi Saito; Moriya

    Full Text Available Abstract: Remote Sensing techniques, such as field spectroscopy provide information with a large level of detail about spectral characteristics of plants enabling the monitoring of crops. The aim of this study is to analyze the influence of viewing angle in estimating the Bidirectional Reflectance Distribution Function (BRDF for the case of sugarcane. The study on the variation of the spectral reflectance profile can help the improvement of algorithms for correction of BRDF in remote sensing images. Therefore, spectral measurements acquired on nadir and different off-nadir view angle directions were considered in the experiments. Change both anisotropy factor and anisotropy index was determined in order to evaluate the BRDF variability in the spectral data of sugarcane. BRDF correction was applied using the Walthall model, thus reducing the BRDF effects. From the results obtained in the experiments, the spectral signatures showed a similar spectral pattern varying mainly in intensity. The anisotropy factor which showed a similar pattern in all wavelengths. The visual analysis of the spectral reflectance profile of sugarcane showed variation mainly in intensity at different angles. The use of Walthall model reduced the BRDF effects and brought the spectral reflectance profiles acquired on different viewing geometry close to nadir viewing. Therefore, BRDF effects on remote sensing data of vegetation cover can be minimized by applying this model. This conclusion contributes to developing suitable algorithms to produce radiometrically calibrated mosaics with remote sensing images taken by aerial platforms.

  2. Geochemical and radiometric surveys of Sabkhet Al-Jaboul area by investigating trace elements, radon measurements and gamma spectrometry

    Jubeli, Y.; Aissa, M.; Al-Hilal, M.

    1999-08-01

    Radiometric and geochemical surveys were carried out over various geological formations in Sabkhet Al-Jaboul and its surrounding environment for evaluating the levels of radioactivity in the area. Therefore, a number of exploration techniques were used in this study such as gamma ray spectrometry, geochemical exploration and soil radon measurements. Although the results of this survey indicate some slight variations of which might be useful to distinguish between various lithological units, most of the obtained data do not reveal any significant radiometric values that could be considered important from the exploration point of view. However, these data were successfully handled to estimate the natural background of radioactivity throughout the geological units of the region. The results also showed the importance of the sedimentary transition contact zone where the continental fresh and salt favourable geochemical environment for uranium precipitation when other fundamental geological requirements for developing such concentrations are available. (author)

  3. Uranium measurement by airborne gamma-ray spectrometry

    Grasty, R.L.

    1975-01-01

    In the airborne measurement of uranium, window type gamma-ray spectrometers are used and it is necessary to correct for scattered high energy radiation from thallium 208 in the thorium decay series. This radiation can be scattered in the crystal, in the ground, and in the air. A theory, analogous to the theory of radioactive decay, is developed; it can adequately explain the spectrum buildup in the uranium window for a point source of thorium oxide immersed to different depths in water and for a detector above the water. The theory is extended to predict the buildup as a function of altitude for detectors of different sizes and shows that errors in the airborne measurement of uranium can be significant if no allowance is made for radiation scattered in the ground and in the air

  4. Identifying areas with potential for high indoor radon levels: analysis of the national airborne radiometric reconnaissance data for California and the Pacific Northwest

    Moed, B.A.; Nazaroff, W.W.; Nero, A.V.; Schwehr, M.B.; Van Heuvelen, A.

    1984-04-01

    Radon-222 is an important indoor air pollutant which, through the inhalation of its radioactive decay products, accounts for nearly half of the effective dose equivalent to the public from natural ionizing radiation. Indoor radon concentrations vary widely, largely because of local and regional differences in the rate of entry from sources. The major sources are soil and rock near building foundations, earth-based building materials, and domestic water; of these, soil and rock are thought to be predominant in many buildings with higher-than-average concentrations. Thus, one key factor in determining radon source potential is the concentration of radium, the progenitor of radon, in surficial rocks and soils. Aerial radiometric data were analyzed, collected for the National Uranium Resource Evaluation Program, for seven Western states to: (1) provide information on the spatial distribution of radium contents in surficial geologic materials for those states; and (2) investigate approaches for using the aerial data, which have been collected throughout the contiguous United States and Alaska, to identify areas where high indoor radon levels may be common. Radium concentrations were found to be relatively low in central and western portions of Washington, Oregon, and northern California; they were found to be relatively high in central and southern California. A field validation study, conducted along two flight-line segments near Spokane, Washington, showed close correspondence between the aerial data, in situ measurements of both radium content and radon flux from soil, and laboratory measurements of both radium content of and radon emanation rate from soil samples. 99 references, 11 figures, 3 tables.

  5. Identifying areas with potential for high indoor radon levels: analysis of the national airborne radiometric reconnaissance data for California and the Pacific Northwest

    Moed, B.A.; Nazaroff, W.W.; Nero, A.V.; Schwehr, M.B.; Van Heuvelen, A.

    1984-04-01

    Radon-222 is an important indoor air pollutant which, through the inhalation of its radioactive decay products, accounts for nearly half of the effective dose equivalent to the public from natural ionizing radiation. Indoor radon concentrations vary widely, largely because of local and regional differences in the rate of entry from sources. The major sources are soil and rock near building foundations, earth-based building materials, and domestic water; of these, soil and rock are thought to be predominant in many buildings with higher-than-average concentrations. Thus, one key factor in determining radon source potential is the concentration of radium, the progenitor of radon, in surficial rocks and soils. Aerial radiometric data were analyzed, collected for the National Uranium Resource Evaluation Program, for seven Western states to: (1) provide information on the spatial distribution of radium contents in surficial geologic materials for those states; and (2) investigate approaches for using the aerial data, which have been collected throughout the contiguous United States and Alaska, to identify areas where high indoor radon levels may be common. Radium concentrations were found to be relatively low in central and western portions of Washington, Oregon, and northern California; they were found to be relatively high in central and southern California. A field validation study, conducted along two flight-line segments near Spokane, Washington, showed close correspondence between the aerial data, in situ measurements of both radium content and radon flux from soil, and laboratory measurements of both radium content of and radon emanation rate from soil samples. 99 references, 11 figures, 3 tables

  6. Comparison of accelerator and radiometric radiocarbon measurements obtained from Late Devensian Lateglacial lake sediments from Llyn Gwernan, North Wales, UK

    Lowe, J.J.; Lowe, S.; Fowler, A.J.

    1988-01-01

    Accelerator mass spectrometry measurements of the radiocarbon activity of various chemical fractions prepared from Late Devensian Lateglacial lake sediments from the site of Llyn Gwernan, near Cader Idris. North Wales are presented and assessed. These are compared with radiocarbon measurements obtained by radiometric (decay) counting which were reported earlier from the same site and are considered in the light of pollen-stratigraphic information. The potensial advantages of accelerator radiocarbon measurements to the assessment of the chronology and correlation of Lateglacial lake sediments are evaluated

  7. Optical Backscattering Measured by Airborne Lidar and Underwater Glider

    James H. Churnside

    2017-04-01

    Full Text Available The optical backscattering from particles in the ocean is an important quantity that has been measured by remote sensing techniques and in situ instruments. In this paper, we compare estimates of this quantity from airborne lidar with those from an in situ instrument on an underwater glider. Both of these technologies allow much denser sampling of backscatter profiles than traditional ship surveys. We found a moderate correlation (R = 0.28, p < 10−5, with differences that are partially explained by spatial and temporal sampling mismatches, variability in particle composition, and lidar retrieval errors. The data suggest that there are two different regimes with different scattering properties. For backscattering coefficients below about 0.001 m−1, the lidar values were generally greater than the glider values. For larger values, the lidar was generally lower than the glider. Overall, the results are promising and suggest that airborne lidar and gliders provide comparable and complementary information on optical particulate backscattering.

  8. Analyzers Measure Greenhouse Gases, Airborne Pollutants

    2012-01-01

    In complete darkness, a NASA observatory waits. When an eruption of boiling water billows from a nearby crack in the ground, the observatory s sensors seek particles in the fluid, measure shifts in carbon isotopes, and analyze samples for biological signatures. NASA has landed the observatory in this remote location, far removed from air and sunlight, to find life unlike any that scientists have ever seen. It might sound like a scene from a distant planet, but this NASA mission is actually exploring an ocean floor right here on Earth. NASA established a formal exobiology program in 1960, which expanded into the present-day Astrobiology Program. The program, which celebrated its 50th anniversary in 2010, not only explores the possibility of life elsewhere in the universe, but also examines how life begins and evolves, and what the future may hold for life on Earth and other planets. Answers to these questions may be found not only by launching rockets skyward, but by sending probes in the opposite direction. Research here on Earth can revise prevailing concepts of life and biochemistry and point to the possibilities for life on other planets, as was demonstrated in December 2010, when NASA researchers discovered microbes in Mono Lake in California that subsist and reproduce using arsenic, a toxic chemical. The Mono Lake discovery may be the first of many that could reveal possible models for extraterrestrial life. One primary area of interest for NASA astrobiologists lies with the hydrothermal vents on the ocean floor. These vents expel jets of water heated and enriched with chemicals from off-gassing magma below the Earth s crust. Also potentially within the vents: microbes that, like the Mono Lake microorganisms, defy the common characteristics of life on Earth. Basically all organisms on our planet generate energy through the Krebs Cycle, explains Mike Flynn, research scientist at NASA s Ames Research Center. This metabolic process breaks down sugars for energy

  9. Study of cloud properties using airborne and satellite measurements

    Boscornea, Andreea; Stefan, Sabina; Vajaiac, Sorin Nicolae

    2014-08-01

    The present study investigates cloud microphysics properties using aircraft and satellite measurements. Cloud properties were drawn from data acquired both from in situ measurements with state of the art airborne instrumentation and from satellite products of the MODIS06 System. The used aircraft was ATMOSLAB - Airborne Laboratory for Environmental Atmospheric Research, property of the National Institute for Aerospace Research "Elie Carafoli" (INCAS), Bucharest, Romania, which is specially equipped for this kind of research. The main tool of the airborne laboratory is a Cloud, Aerosol and Precipitation Spectrometer - CAPS (30 bins, 0.51- 50 μm). The data was recorded during two flights during the winter 2013-2014, over a flat region in the south-eastern part of Romania (between Bucharest and Constanta). The analysis of cloud particle size variations and cloud liquid water content provided by CAPS can explain cloud processes, and can also indicate the extent of aerosols effects on clouds. The results, such as cloud coverage and/or cloud types, microphysical parameters of aerosols on the one side and the cloud microphysics parameters obtained from aircraft flights on the other side, was used to illustrate the importance of microphysics cloud properties for including the radiative effects of clouds in the regional climate models.

  10. Airborne UV DIAL Measurements of Ozone and Aerosols

    Grant, William B.; Browell, Edward V.

    2000-01-01

    The NASA Langley Research Center's airborne UV Differential Absorption Lidar (DIAL) system measures vertical profiles of ozone and aerosols above and below the aircraft along its flight track. This system has been used in over 20 airborne field missions designed to study the troposphere and stratosphere since 1980. Four of these missions involved tropospheric measurement programs in the Pacific Ocean with two in the western North Pacific and two in the South Pacific. The UV DIAL system has been used in these missions to study such things as pollution outflow, long-range transport, and stratospheric intrusions; categorize the air masses encountered; and to guide the aircraft to altitudes where interesting features can be studied using the in situ instruments. This paper will highlight the findings with the UV DIAL system in the Pacific Ocean field programs and introduce the mission planned for the western North Pacific for February-April 2001. This will be an excellent opportunity for collaboration between the NASA airborne mission and those with ground-based War systems in Asia Pacific Rim countries to make a more complete determination of the transport of air from Asia to the western Pacific.

  11. Measurement of airborne 218Po - A Bayesian approach

    Groer, P.G.; Lo, Y.

    1996-01-01

    The standard mathematical treatment of the buildup and decay of airborne radionuclides on a filter paper uses the solutions of the so-called bateman equations adapted to the sampling process. The equations can be interpreted as differential equations for the expectation of an underlying stochastic process, which describes the random fluctuations in the accumulation and decay of the sampled radioactive atoms. The process for the buildup and decay of airborne 218 Po can be characterized as an open-quotes immigration-death processclose quotes in the widely adopted, biologically based jargon. The probability distribution for the number of 218 Po atoms, accumulated after sampling time t, is Poisson. We show that the distribution of the number of counts, registered by a detector with efficiency ε during a counting period T after the end of sampling, it also Poisson, with mean dependent on ε,t,T, the flowrate and N o , the number of airborne 218 Po atoms per unit volume. This Poisson distribution was used to construct the likelihood given the observed number of counts. After inversion with Bayes' Theorem we obtained the posterior density for N o . This density characterizes the remaining uncertainty about the measured under of 218 Po atoms per unit volume of air. 6 refs., 3 figs., 1 tab

  12. Radiometric measurements on the fabrication of non-destructive assay standards for WIPP-Performance Demonstration Program

    Wong, A.S.; Marshall, R.S.

    1997-04-01

    The Inorganic Elemental Analysis Group of LANL has prepared several different sets of working reference materials (WRMs). These WRMs are prepared by blending quantities of nuclear materials (plutonium, americium, and enriched uranium) with diatomaceous earth. The blends are encapsulated in stainless steel cylinders. These WRMs are being measured as blind controls in neutron and gamma based non-destructive assay (NDA) instruments. Radiometric measurements on the blending homogeneity and verification on a set of sixty three plutonium based WRMs are discussed in this paper

  13. Airborne plutonium and americium concentrations measured from the top of Rattlesnake Mountain

    Sehmel, G.A.

    1979-01-01

    Airborne plutonium-239+240 and americium-241 blowing from offsite was measured in an initial experiment at the top of Rattlesnake Mountain. Average airborne concentration measured was similar to fallout concentrations. Airborne plutonium concentrations were independent of wind speed for seven wind speed increments between 0.5 and 31 m/sec. In contrast the airborne americium concentration was a minimum at a wind speed of approximately 7 m/sec. Similarly, the airborne solids concentration in μg/m 3 was a minimum at an intermediate wind speed increment of 7 to 11 m/sec

  14. Radiometric dating

    Das, N.R.

    2017-01-01

    Since the discovery of natural radioactivity in uranium, in the last decade of the nineteenth century, the nuclear property of radioactive decay of radionuclides at immutable rates has been effectively utilized in dating of varieties of naturally occurring geological matrices and the organisms which constantly replenish their "1"4C supply through respiration when alive on earth. During the period, applications of radiometric dating techniques have been extensively diversified and have enabled the geologists to indicate the absolute time scales of geological formations and the evolution of the solar system, the earth, meteorites, lunar rocks, etc. and the archaeologists to record the facts of history of several important events like dinosaur era, Iceman, the Shroud in Turin and many other ancient artefacts. In the development of dating methods, varieties of naturally occurring radio-isotopic systems with favorable half-lives ranging from about 10 years to over 100 billion years have been used as radiometric clocks. (author)

  15. Training course on radiometric prospecting techniques

    1979-01-01

    A training course on radiometric prospecting techniques was presented by the Atomic Energy Board in collaboration with the South African Geophysical Association and the Geological Society of South Africa. Various aspects related to uranium prospecting were discussed e.g. the uranium supply and demand position, the basic physics of radioactivity, uranium geochemistry, mineralogy and mobility, the instrumentation and techniques used in uranium exploration, for example, borehole logging, radon emanometry and airborne radiometric surveys and also data processing and interpretation methods

  16. Radiometric well logging instruments

    Davydov, A.V.

    1975-01-01

    The technical properties of well instruments for radioactive logging used in the radiometric logging complexes PKS-1000-1 (''Sond-1'') and PRKS-2 (''Vitok-2'') are described. The main features of the electric circuit of the measuring channels are given

  17. Krypton-85 and other airborne radioactivity measurements throughout Ireland

    Smith, K.J.; Murray, M.; Wong, J.; Sequeira, S.; Long, S.C.; Rafferty, B.

    2004-01-01

    In compliance with articles 35 and 36 of the EURATOM Treaty, the Radiological Protection Institute of Ireland (RPII) undertakes a comprehensive programme of radioactivity monitoring in the Irish terrestrial environment. Radioactivity is present in the terrestrial environment due to natural processes, the testing of nuclear weapons in the atmosphere, accidents such as the Chernobyl accident and the routine discharge of radionuclides from nuclear installations. The RPII monitors airborne radioactivity concentrations at ten stations throughout Ireland, of which, nine are equipped with low volume particulate samplers and one, in Dublin, with a high volume particulate sampler. The low volume particulate samples are assessed for total beta activity and high volume samples for gamma emitting radionuclides such as caesium-137 and beryllium-7. In addition, air sampled at the RPII laboratory in Dublin, is monitored for krypton-85, a radioactive noble gas, released into the environment primarily as a result of the reprocessing of nuclear fuel at installations such as Sellafield in the UK and La Hague in France. Since the inception of the krypton measurements in 1993 a trend of increasing atmospheric concentrations has been observed. The results of the krypton-85 monitoring, as well as the airborne radioactivity concentration measurements, will be presented and discussed in this paper. (author)

  18. Airborne Measurements of Atmospheric Methane Using Pulsed Laser Transmitters

    Numata, Kenji; Riris, Haris; Wu, Stewart; Gonzalez, Brayler; Rodriguez, Michael; Hasselbrack, William; Fahey, Molly; Yu, Anthony; Stephen, Mark; Mao, Jianping; hide

    2016-01-01

    Atmospheric methane (CH4) is the second most important anthropogenic greenhouse gas with approximately 25 times the radiative forcing of carbon dioxide (CO2) per molecule. At NASA Goddard Space Flight Center (GSFC) we have been developing a laser-based technology needed to remotely measure CH4 from orbit. We report on our development effort for the methane lidar, especially on our laser transmitters and recent airborne demonstration. Our lidar transmitter is based on an optical parametric process to generate near infrared laser radiation at 1651 nanometers, coincident with a CH4 absorption. In an airborne flight campaign in the fall of 2015, we tested two kinds of laser transmitters --- an optical parametric amplifier (OPA) and an optical parametric oscillator (OPO). The output wavelength of the lasers was rapidly tuned over the CH4 absorption by tuning the seed laser to sample the CH4 absorption line at several wavelengths. This approach uses the same Integrated Path Differential Absorption (IPDA) technique we have used for our CO2 lidar for ASCENDS. The two laser transmitters were successfully operated in the NASAs DC-8 aircraft, measuring methane from 3 to 13 kilometers with high precision.

  19. Methane airborne measurements and comparison to global models during BARCA

    Beck, Veronika; Chen, Huilin; Gerbig, Christoph; Bergamaschi, Peter; Bruhwiler, Lori; Houweling, Sander; Röckmann, Thomas; Kolle, Olaf; Steinbach, Julia; Koch, Thomas; Sapart, Célia J.; van der Veen, Carina; Frankenberg, Christian; Andreae, Meinrat O.; Artaxo, Paulo; Longo, Karla M.; Wofsy, Steven C.

    2012-08-01

    Tropical regions, especially the Amazon region, account for large emissions of methane (CH4). Here, we present CH4 observations from two airborne campaigns conducted within the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) project in the Amazon basin in November 2008 (end of the dry season) and May 2009 (end of the wet season). We performed continuous measurements of CH4 onboard an aircraft for the first time in the Amazon region, covering the whole Amazon basin with over 150 vertical profiles between altitudes of 500 m and 4000 m. The observations support the finding of previous ground-based, airborne, and satellite measurements that the Amazon basin is a large source of atmospheric CH4. Isotope analysis verified that the majority of emissions can be attributed to CH4 emissions from wetlands, while urban CH4 emissions could be also traced back to biogenic origin. A comparison of five TM5 based global CH4 inversions with the observations clearly indicates that the inversions using SCIAMACHY observations represent the BARCA observations best. The calculated CH4 flux estimate obtained from the mismatch between observations and TM5-modeled CH4 fields ranges from 36 to 43 mg m-2 d-1 for the Amazon lowland region.

  20. Measurement of airborne droplets by the magnesium oxide method

    May, K R

    1950-01-01

    A complete calibration has been made for the first time of the method of detecting and measuring airborne droplets whereby the permanent impressions made when they strike a layer of magnesium oxide smoked on a glass slide are measured microscopically. A size range of 200 to 10 microns and a wide range of liquids and impact velocities were investigated, and it was found that the ratio of true drop size to impression size is constant at 0.86 for droplets greater than 20 microns of any liquid. The method fails below 10 microns. The calibration was made against an absolute method of droplet measurement, also against the so-called focal-length method. Droplets of any desired size were generated by a uniform spray apparatus.

  1. Method for measuring the size distribution of airborne rhinovirus

    Russell, M.L.; Goth-Goldstein, R.; Apte, M.G.; Fisk, W.J.

    2002-01-01

    About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor

  2. Method for measuring the size distribution of airborne rhinovirus

    Russell, M.L.; Goth-Goldstein, R.; Apte, M.G.; Fisk, W.J.

    2002-01-01

    About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor.

  3. Changing methodology for measuring airborne radioactive discharges from nuclear facilities

    Glissmeyer, J.A.; Ligotke, M.W.

    1995-05-01

    The US Environmental Protection Agency (USEPA) requires that measurements of airborne radioactive discharges from nuclear facilities be performed following outdated methods contained in the American National Standards Institute (ANSI) N13.1-1969 Guide to Sampling Airborne Radioactive Materials in Nuclear Facilities. Improved methods are being introduced via two paths. First, the ANSI standard is being revised, and second, EPA's equivalency granting process is being used to implement new technology on a case-by-case or broad basis. The ANSI standard is being revised by a working group under the auspices of the Health Physics Society Standards Committee. The revised standard includes updated methods based on current technology and a performance-based approach to design. The performance-based standard will present new challenges, especially in the area of performance validation. Progress in revising the standard is discussed. The US Department of Energy recently received approval from the USEPA for an alternate approach to complying with air-sampling regulations. The alternate approach is similar to the revised ANSI standard. New design tools include new types of sample extraction probes and a model for estimating line-losses for particles and radioiodine. Wind tunnel tests are being performed on various sample extraction probes for use at small stacks. The data show that single-point sampling probes are superior to ANSI-Nl3.1-1969 style multiple-point sample extraction probes

  4. Measurements of sea ice by satellite and airborne altimetry

    Kildegaard Rose, Stine

    the modal freeboard heights of 55 cm retrieved from the laser scanner data with the 25 cm retrieved from CryoSat-2 indicates a snow layer of 30 cm, due to the theory that a laser is reflected at the air/snow interface, while the radar is reflected at the snow/ice interface. In the other area, the modal...... freeboard is found to be 35 cm for both the airborne and satellite data implying, that the radar signal is here reflected from the snow surface, probably due to weather conditions. CryoSat-2 is very sensitive to returns from specular surfaces, even if they appear o_-nadir. This contaminates the “true...... and in fjord systems. The Greenland fjords exhange freshwater between the glaciers and the ocean. Measuring a snapshot of the ice mélange in front of Kangiata Nunˆta Sermia in southwest Greenland with airborne LiDAR, gives an estimate of the ice disharge since last autuum. The total volume of 1:70 _ 1:26 GT...

  5. Air-borne shape measurement of parabolic trough collector fields

    Prahl, Christoph; Röger, Marc; Hilgert, Christoph

    2017-06-01

    The optical and thermal efficiency of parabolic trough collector solar fields is dependent on the performance and assembly accuracy of its components such as the concentrator and absorber. For the purpose of optical inspection/approval, yield analysis, localization of low performing areas, and optimization of the solar field, it is essential to create a complete view of the optical properties of the field. Existing optical measurement tools are based on ground based cameras, facing restriction concerning speed, volume and automation. QFly is an airborne qualification system which provides holistic and accurate information on geometrical, optical, and thermal properties of the entire solar field. It consists of an unmanned aerial vehicle, cameras and related software for flight path planning, data acquisition and evaluation. This article presents recent advances of the QFly measurement system and proposes a methodology on holistic qualification of the complete solar field with minimum impact on plant operation.

  6. Multipurpose radiometric equipment provided with a microcontroller for use in industrial applications (e.g., measurements of level, density, thickness, etc.)

    Kluger, A.; Popescu, C.; Patrascu, S.

    1998-01-01

    The goal of this research was to modernize the radiometric equipment used for the control and automation of technological processes. A microcontroller-equipped electronic block was designed and realized, capable of performing all the tasks of a radiometric system, regardless of the application range (i.e. measurement of density, thickness, level, composition, etc.) or the detector type employed. In this work, the experimental model for the multipurpose radiometric equipment was devised. The electronic unit was designed using a high performance controller 80C552 and was provided with low-power transceivers for RS-232 and RS-485 communication with a PC. The results of the measured parameters are displayed using a graphic liquid crystal display, LCD G 242 C, that allows both graphics and character display. (authors)

  7. Airborne Lidar Measurements of Aerosol Optical Properties During SAFARI-2000

    McGill, M. J.; Hlavka, D. L.; Hart, W. D.; Welton, E. J.; Campbell, J. R.; Starr, David OC. (Technical Monitor)

    2002-01-01

    The Cloud Physics Lidar (CPL) operated onboard the NASA ER-2 high altitude aircraft during the SAFARI-2000 field campaign. The CPL provided high spatial resolution measurements of aerosol optical properties at both 1064 nm and 532 nm. We present here results of planetary boundary layer (PBL) aerosol optical depth analysis and profiles of aerosol extinction. Variation of optical depth and extinction are examined as a function of regional location. The wide-scale aerosol mapping obtained by the CPL is a unique data set that will aid in future studies of aerosol transport. Comparisons between the airborne CPL and ground-based MicroPulse Lidar Network (MPL-Net) sites are shown to have good agreement.

  8. Airborne anthropogenic radioactivity measurements from an international radionuclide monitoring system

    Mason, L.R.; Bohner, J.D.; Williams, D.L.

    1998-01-01

    Anthropogenic radioactivity is being measured in near-real time by an international monitoring system designed to verify the Comprehensive Nuclear Test Ban Treaty. Airborne radioactivity measurements are conducted in-situ by stations that are linked to a central data processing and analysis facility. Aerosols are separated by high-volume air sampling with high-efficiency particulate filters. Radio-xenon is separated from other gases through cryogenic methods. Gamma-spectrometry is performed by high purity germanium detectors and the raw spectral data is immediately transmitted to the central facility via Internet, satellite, or modem. These highly sensitive sensors, combined with the automated data processing at the central facility, result in a system capable of measuring environmental radioactivity on the microbecquerel scale where the data is available to scientists within minutes of the field measurement. During the past year, anthropogenic radioactivity has been measured at approximately half of the stations in the current network. Sources of these measured radionuclides include nuclear power plant emissions, Chernobyl resuspension, and isotope production facilities. The ability to thoroughly characterize site-specific radionuclides, which contribute to the radioactivity of the ambient environment, will be necessary to reduce the number of false positive events. This is especially true of anthropogenic radionuclides that could lead to ambiguous analysis. (author)

  9. OPTIMIZING THE PAKS METHOD FOR MEASURING AIRBORNE ACROLEIN

    Airborne acrolein is produced from the combustion of fuel and tobacco and is of concern due to its potential for respiratory tract irritation and other adverse health effects. DNPH active-sampling is a method widely used for sampling airborne aldehydes and ketones (carbonyls); ...

  10. Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

    Sehmel, G.A.

    1978-01-01

    Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height

  11. Application of porous foams for size-selective measurements of airborne wheat allergen

    Bogdanovic, J.; Pater, A.J. de; Doekes, G.; Wouters, I.M.; Heederik, D.J.J.

    2006-01-01

    Background: Exposure to airborne wheat allergen is a well-known cause of bakers' allergy and asthma. Airborne wheat allergen can be measured by enzyme immunoassays (EIAs) in extracts of inhalable dust samples, but only limited knowledge is available on the size distribution of wheat

  12. Using Airborne SAR Interferometry to Measure the Elevation of a Greenland Ice Cap

    Dall, Jørgen; Keller, K.; Madsen, S.N.

    2000-01-01

    A digital elevation model (DEM) of an ice cap in Greenland has been generated from airborne SAR interferometry data, calibrated with a new algorithm, and compared with airborne laser altimetry profiles and carrier-phase differential GPS measurements of radar reflectors deployed on the ice cap...... with GPS data and calibrated laser data....

  13. Representativeness of the IAGOS airborne measurements in the lower troposphere

    H. Petetin

    2018-03-01

    Full Text Available In the framework of the In Service Aircraft for Global Observing System (IAGOS program, airborne in-situ O3 and CO measurements are performed routinely using in-service aircraft, providing vertical profiles from the surface to about 10–12 km. Due to the specificity of IAGOS measurements (measurements around busy international airports, uncertainties exist on their representativeness in the lower troposphere as they may be impacted by emissions related to airport activities and/or other aircraft. In this study, we thus investigate how the IAGOS measurements in the lower troposphere compare with nearby surface stations (from the local Air Quality monitoring network (AQN and more distant regional surface stations (from the Global Atmospheric Watch (GAW network. The study focuses on Frankfurt but some results at other European airports (Vienna, Paris are also discussed. Results indicate that the IAGOS observations close to the surface do not appear to be strongly impacted by local emissions related to airport activities. In terms of mixing ratio distribution, seasonal variations and trends, the CO and O3 mixing ratios measured by IAGOS in the first few hundred metres above the surface have similar characteristics to the mixing ratios measured at surrounding urban background stations. Higher in altitude, both the difference with data from the local AQN and the consistency with the GAW regional stations are higher, which indicates a larger representativeness of the IAGOS data. Despite few quantitative differences with Frankfurt, consistent results are obtained in the two other cities Vienna and Paris. Based on 11 years of data (2002–2012, this study thus demonstrates that IAGOS observations in the lowest troposphere can be used as a complement to surface stations to study the air quality in/around the agglomeration, providing important information on the vertical distribution of pollution.

  14. Functional requirements document for measuring emissions of airborne radioactive materials

    Glissmeyer, J.A.; Alvarez, J.L.; Hoover, M.D.; Newton, G.C.; McFarland, A.R.; Rodgers, J.C.

    1994-11-01

    This document states the general functional requirements for systems and procedures for measuring emissions of airborne radioactive materials from facilities administered by the Westinghouse Hanford Company (WHC). The following issues are addressed in this document: lg-bullet definition of the program objectives lg-bullet selection of the overall approach to collecting the samples lg-bullet sampling equipment design lg-bullet sampling equipment maintenance and quality assurance issues. The following issues are not addressed in this document: lg-bullet air sampling in work areas or containments lg-bullet selection of specific on-line sample monitoring instrumentation lg-bullet analyzing collected samples lg-bullet reporting and interpreting results. The document provides equipment design guidance that is performance based rather than prescriptive. Locations from which samples are obtained should exhibit mixing of the contaminants with the airstream and acceptable air flow characteristics. Sample collection equipment and effluent and sample flow elements should meet defined performance standards. Quality control and assurance requirements specific to sample collection, equipment inspection, and calibration are presented. Key sample collection performance requirements are summarized in Section 5.4. The intent of this document is to assist WHC in demonstrating a high quality of air emission measurements with verified system performance based on documented system design, testing, inspection, and maintenance

  15. Coordinated airborne and satellite measurements of equatorial plasma depletions

    Weber, E.J.; Brinton, H.C.; Buchau, J.; Moore, J.G.

    1982-01-01

    A series of experiments was conducted in December 1979 to investigate the structure of plasma depletions in the low latitude, nightime ionosphere. The measurements included all sky imaging photometer (ASIP), ionosonde and amplitude scintillation observations from the AFGL Airborne Ionospheric Observatory (AIO), and in situ ion density measurements from the Atmosphere Explorer (AE-E) Bennett Ion Mass Spectrometer (BIMS). The AIO performed two flights along the Ascension Island (-18 0 MLAT) magnetic meridian: one in the southern hemisphere and one near the Ascension conjugate point in the northern hemisphere. During these flights, measurements from the AE-E satellite at 434 km altitude are compared with simultaneous remote ionospheric measurements from the AIO. Density biteouts of approximately one order of magnitude in the dominant ion O + , were mapped to lower altitudes along magnetic field lines for comparison with 6300-A and 7774-A O I airglow depletions. Because of the different airglow production mechanisms (dissociative recombination of O +2 for 6300 A and radiative recombination of O + for 7774 A) the 6300-A depletions reflect plasma depletions near the bottomside of the F layer, while those at 7774 A are located near the peak of the layer. The O + biteouts map directly into the 7774-A airglow depletions in the same hemisphere and also when traced into the opposite hemisphere, which indicates magnetic flux tube alignment over north-south distances of approx.2220 km. The 6300-A (bottomside) depletions are wider in longitude than the 7774-A (F-peak) depletions near the equatorward edge of the Appleton anomaly. This difference in topside and bottomside structure is used to infer large-scale structure near the anomaly and to relate this to structure, commonly observed near the magnetic equator by the ALTAIR radar

  16. Radiometric Correction of Close-Range Spectral Image Blocks Captured Using an Unmanned Aerial Vehicle with a Radiometric Block Adjustment

    Eija Honkavaara

    2018-02-01

    Full Text Available Unmanned airborne vehicles (UAV equipped with novel, miniaturized, 2D frame format hyper- and multispectral cameras make it possible to conduct remote sensing measurements cost-efficiently, with greater accuracy and detail. In the mapping process, the area of interest is covered by multiple, overlapping, small-format 2D images, which provide redundant information about the object. Radiometric correction of spectral image data is important for eliminating any external disturbance from the captured data. Corrections should include sensor, atmosphere and view/illumination geometry (bidirectional reflectance distribution function—BRDF related disturbances. An additional complication is that UAV remote sensing campaigns are often carried out under difficult conditions, with varying illumination conditions and cloudiness. We have developed a global optimization approach for the radiometric correction of UAV image blocks, a radiometric block adjustment. The objective of this study was to implement and assess a combined adjustment approach, including comprehensive consideration of weighting of various observations. An empirical study was carried out using imagery captured using a hyperspectral 2D frame format camera of winter wheat crops. The dataset included four separate flights captured during a 2.5 h time period under sunny weather conditions. As outputs, we calculated orthophoto mosaics using the most nadir images and sampled multiple-view hyperspectral spectra for vegetation sample points utilizing multiple images in the dataset. The method provided an automated tool for radiometric correction, compensating for efficiently radiometric disturbances in the images. The global homogeneity factor improved from 12–16% to 4–6% with the corrections, and a reduction in disturbances could be observed in the spectra of the object points sampled from multiple overlapping images. Residuals in the grey and white reflectance panels were less than 5% of the

  17. The role of airborne radiometric survey in defining the distribution of phosphate rocks in the Syrian desert and the Northern Palmyrides

    Jubeli, Y.M.

    2000-01-01

    Gamma-ray spectrometry, an effective tool in geological mapping, was used to define boundaries between various lithological formations in three adjacent areas of Central Syria, namely, the Syrian Desert, Ar Rassafeh Badiayat and the Northern Palmyrides mountains. This paper describes the role of an airborne gamma spectrometric survey which was originally undertaken to assist uranium exploration. Interpretation of the total count data obtained through the survey has led to significant modifications and corrections to the previously published distribution map of the Palaeogene phosphate rocks. Another important result to the survey is the discovery of four previously unknown phosphorite horizons in the Rasm Al-Aawabed area of the Northern Palmyrides. In addition, previously unknown phosphatic horizons are outlined in the other study areas. The importance of this technique as an effective prospecting method, not only for U but also for exploring for the economically important phosphorite formations in Syria, is emphasized. Furthermore, its role in geological mapping is stressed, especially in areas that lack sufficient geological data. (author)

  18. Airborne measurement of peroxy radicals in the lower troposphere

    Andrés Hernández, Maria Dolores; Horstjann, Markus; Kartal, Deniz; Krebsbach, Marc; Linke, Christian; Lichtenstern, Michael; Andrey, Javier; Burrows, John P.

    2013-04-01

    The importance of peroxy radicals in the tropospheric chemistry is well recognized in the scientific literature. Hydroxy- and organic peroxy radicals (HO2 and RO2, R being an organic chain) are key intermediates in the OH radical initiated oxidation of CO and SO2, of volatile organic compounds (VOC), in the ozonolysis of alkenes and photo-oxidation of carbonyl species. Peroxy radicals are responsible for the ozone production in the troposphere, the formation of peroxides and other oxidants. Although radical chemistry in the troposphere has been subject of intensive research in the past three decades, it is still very few known about the vertical distribution of peroxy radicals. Airborne observations are scarce in spite of their particular importance to improve the understanding of the tropospheric chemistry and the oxidising capacity of the atmosphere at different altitudes. In situ trace gas measurements were carried out in summer 2010 on board of the INTA (Instituto Nacional de Técnicas Aeroespaciales) C212 aircraft over Spain in the frame of the EUFAR project VERDRILLT (VERtical Distribution of Radicals In the Lower Layers of the Troposphere), and in cooperation with the DLR (Deutsches Zentrum für Luft- und Raumfahrt), the University of Wuppertal, the CEAM (Centro de Estudios Ambientales del Mediterráneo) and the UPV-EHU University in Bilbao. VERDRILLT aimed at getting a deeper understanding of the vertical distribution of peroxy radicals in the lower layers of the troposphere. Measurements were taken over urban areas and extensions of different vegetation under meteorological conditions favouring active photochemistry and convection from the ground into close atmospheric layers. Results and main findings will be presented and discussed.

  19. Measurement of airborne concentrations of radon-220 daughter products by alpha-particle spectrometry

    Kerr, G.D.; Ryan, M.T.; Perdue, P.T.

    1978-01-01

    The decay of naturally occurring uranium-238 and thorium-232 produces radon-222 and radon-220 isotopes which can escape into the atmosphere. If these radon gases become concentrated in air, their daughter products may present an inhalation hazard to man. The airborne concentrations of radon-222 can usually be measured very accurately in the presence of normal airborne concentrations of radon-220 and its daughters. In contrast, the measurements of the airborne concentrations of radon-220 daughters are usually complicated by the presence of radon-222 and its daughters even at normally occurring airborne concentrations. The complications involved in these measurements can be overcome in most situations by using an alpha particle spectrometer to distinguish the activity of radon-222 daughters from that due to radon-220 daughters collected on a filter. A practical spectrometer for field measurements of alpha particle activity on a filter is discussed

  20. Methane airborne measurements and comparison to global models during BARCA

    Beck, Veronika; Chen, Huilin; Gerbig, Christoph; Bergamaschi, Peter; Bruhwiler, Lori; Houweling, Sander; Rockmann, Thomas; Kolle, Olaf; Steinbach, Julia; Koch, Thomas; Sapart, Celia J.; van der Veen, Carina; Frankenberg, Christian; Andreae, Meinrat O.; Artaxo, Paulo; Longo, Karla M.; Wofsy, Steven C.

    2012-01-01

    Tropical regions, especially the Amazon region, account for large emissions of methane (CH4). Here, we present CH4 observations from two airborne campaigns conducted within the BARCA (Balanco Atmosferico Regional de Carbono na Amazonia) project in the Amazon basin in November 2008 (end of the dry

  1. Methane airborne measurements and comparison to global models during BARCA

    Beck, V.; Chen, H.; Gerbig, C; Bergamaschi, P.; Bruhwiler, L.; Houweling, S.; Röckmann, T.; Kolle, O.; Steinbach, J.; Koch, T.; Sapart, C.J.; van der Veen, C.; Frankenberg, C.; Andreae, M.O.; Artaxo, P.; Longo, K.M.; Wofsy, S.C.

    2012-01-01

    Tropical regions, especially the Amazon region, account for large emissions of methane (CH4). Here, we present CH4 observations from two airborne campaigns conducted within the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) project in the Amazon basin in November 2008 (end of the dry

  2. Comparative study of radiometric and calorimetric methods for total hemispherical emissivity measurements

    Monchau, Jean-Pierre; Hameury, Jacques; Ausset, Patrick; Hay, Bruno; Ibos, Laurent; Candau, Yves

    2018-05-01

    Accurate knowledge of infrared emissivity is important in applications such as surface temperature measurements by infrared thermography or thermal balance for building walls. A comparison of total hemispherical emissivity measurement was performed by two laboratories: the Laboratoire National de Métrologie et d'Essais (LNE) and the Centre d'Études et de Recherche en Thermique, Environnement et Systèmes (CERTES). Both laboratories performed emissivity measurements on four samples, chosen to cover a large range of emissivity values and angular reflectance behaviors. The samples were polished aluminum (highly specular, low emissivity), bulk PVC (slightly specular, high emissivity), sandblasted aluminum (diffuse surface, medium emissivity), and aluminum paint (slightly specular surface, medium emissivity). Results obtained using five measurement techniques were compared. LNE used a calorimetric method for direct total hemispherical emissivity measurement [1], an absolute reflectometric measurement method [2], and a relative reflectometric measurement method. CERTES used two total hemispherical directional reflectometric measurement methods [3, 4]. For indirect techniques by reflectance measurements, the total hemispherical emissivity values were calculated from directional hemispherical reflectance measurement results using spectral integration when required and directional to hemispherical extrapolation. Results were compared, taking into account measurement uncertainties; an added uncertainty was introduced to account for heterogeneity over the surfaces of the samples and between samples. All techniques gave large relative uncertainties for a low emissive and very specular material (polished aluminum), and results were quite scattered. All the indirect techniques by reflectance measurement gave results within ±0.01 for a high emissivity material. A commercial aluminum paint appears to be a good candidate for producing samples with medium level of emissivity

  3. Implementing the ban on smoking in Israeli pubs: measuring airborne nicotine and enforcement by local authorities.

    Satran, Carmit; Drach-Zahavy, Anat; Hammond, S Katharine; Baron-Epel, Orna

    2014-06-01

    In 2007 an amendment to the law restricting smoking in pubs and bars (P&Bs) was enacted in Israel. However, a year after the ban only slight decreases in airborne smoke in P&Bs in one city have been reported. We aimed to assess levels of airborne nicotine in Israeli P&Bs and to measure ifself-reported enforcement of the law by local officials was associated with levels of airborne nicotine in P&Bs. Airborne nicotine levels were measured in 72 P&Bs in 29 towns in Israel; this consisted of 90% of eligible towns. In addition, 73 local authority officials were interviewed in 25 of these towns. The officials were asked to assess the local authority's level of enforcement of the law banning smoking in P&Bs. The association of levels of airborne nicotine with the levels of enforcement of the law was calculated. Data were collected during 2009-2010 and analyzed in 2010-2011. Levels of airborne nicotine were comparatively high in P&Bs. No association was detected between levels of nicotine and the P&Bs' characteristics. In the larger towns, levels of airborne nicotine were higher. In 16% of towns the local authority officials reported high levels of law enforcement. Generally, levels of reported enforcement by local authorities were low and did not predict levels of airborne nicotine in the P&Bs. Self-reported local authorities' law enforcement was not associated with levels of airborne nicotine in P&Bs in these towns. There is a need to develop ways to increase law enforcement by the local authorities or other agencies.

  4. Significance of radioelement concentration measurements made by airborne gamma-ray spectrometry over the Canadian Shield

    Charbonneau, B.W.; Killeen, P.G.; Carson, J.M.; Cameron, G.W.; Richardson, K.A.

    1976-01-01

    Results of airborne gamma-ray spectrometer surveys conducted by the Geological Survey of Canada are presented as maps contoured in units of radioelement and concentration ratios. These contoured values represent the average surface concentrations of the radioelements over areas of the order of several square kilometres. The relationship between this ''average surface concentration'' and the radioelement concentration in bedrock underlying the area depends on: (1) the percentage of outcrop; (2) the relation between overburden and bedrock radioelement concentration; (3) percentage of marshland or surface water in the area; (4) soil moisture; and (5) density of vegetation. More than 2500 portable gamma-ray spectrometer analyses of outcrop and overburden have been made in the Bancroft, Elliot Lake and Fort Smith areas of the Canadian Precambrian Shield. In the areas examined, the radioelement concentrations in glacial drift reflect the concentrations in the underlying bedrock. Rocks with near-crustal average contents of thorium, uranium and potassium are overlain by glacial drift having approximately the same concentrations. As the concentration in bedrock increases, the concentration in the local overburden also increases, but not to the same extent. In addition, in-situ gamma-ray spectrometry measurements were made at almost 1000 stations within the area of airborne surveys near Mont Laurier and Elliot Lake. These ground measurements were compared with the airborne measurements by averaging the values for all those ground stations located in the areas between each contour level on airborne maps. Radioelement concentrations in bedrock are considerably higher than corresponding airborne measurements, and this difference between bedrock and airborne values increases at higher radioelement concentrations. Radioelement concentrations in glacial drift are only slightly higher than airborne contour values for the same area. Airborne contour maps of the radioelement ratios

  5. Bayesian model for matching the radiometric measurements of aerospace and field ocean color sensors.

    Salama, Mhd Suhyb; Su, Zhongbo

    2010-01-01

    A Bayesian model is developed to match aerospace ocean color observation to field measurements and derive the spatial variability of match-up sites. The performance of the model is tested against populations of synthesized spectra and full and reduced resolutions of MERIS data. The model derived the scale difference between synthesized satellite pixel and point measurements with R(2) > 0.88 and relative error < 21% in the spectral range from 400 nm to 695 nm. The sub-pixel variabilities of reduced resolution MERIS image are derived with less than 12% of relative errors in heterogeneous region. The method is generic and applicable to different sensors.

  6. Bayesian Model for Matching the Radiometric Measurements of Aerospace and Field Ocean Color Sensors

    Mhd. Suhyb Salama

    2010-08-01

    Full Text Available A Bayesian model is developed to match aerospace ocean color observation tofield measurements and derive the spatial variability of match-up sites. The performance of the model is tested against populations of synthesized spectra and full and reduced resolutions of MERIS data. The model derived the scale difference between synthesized satellite pixel and point measurements with R2 > 0.88 and relative error < 21% in the spectral range from 400 nm to 695 nm. The sub-pixel variabilities of reduced resolution MERIS image are derived with less than 12% of relative errors in heterogeneous region. The method is generic and applicable to different sensors.

  7. Results of radiometric and geochemical measurement for the natural radioactivity map of Slovenia

    Mišo Andjelov

    1994-12-01

    Full Text Available In 1990, a program was initiated to cover Slovenia with portable gamma-ray spectrometer measurements on a 5 x 5 km grid. The measurements were performed with a four channel Scintrex GAD-6 spectrometer. Five gamma-ray measurements were taken at each of 816 locations. Samples of the upper 10 cm of soil profile were collected for laboratory analysis. Uranium in samples was determinedby delayed neutron method (DNC. Other 35 elements: Ag, Al, As, Au, Ba, Be,Bi, Ca, Co, Cr, Cu, Fe, K, La, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Sb, Se, Sn, Sr, Th, Ti,U, V, W, Y, Zn and Zr were analyzed by plasma-coupled emission spectrometry (ICP. The field gamma-ray measurements were converted to ground concentrationsof potassium, uranium and thorium. These show good correlation with the laboratory analyses of soil samples. Regardless of the wide spaced sampling, the produced maps show relatively good correlation with main geological units. They demonstrated that the methodology can be successfully implemented for environmental monitoring, geological mapping and mineral exploration. The product ofthis project is the frist natural background radioactivity map of Slovenia covering the entire country.

  8. Emission Spectroscopy and Radiometric Measurements in the NASA Ames IHF Arc Jet Facility

    Winter, Michael W.; Raiche, George A.; Prabhu, Dinesh K.

    2012-01-01

    Plasma diagnostic measurement campaigns in the NASA Ames Interaction Heating Facility (IHF) have been conducted over the last several years with a view towards characterizing the flow in the arc jet facility by providing data necessary for modeling and simulation. Optical emission spectroscopy has been used in the plenum and in the free jet of the nozzle. Radiation incident over a probe surface has also been measured using radiometry. Plenum measurements have shown distinct radial profiles of temperature over a range of operating conditions. For cases where large amounts of cold air are added radially to the main arc-heated stream, the temperature profiles are higher by as much as 1500 K than the profiles assumed in flow simulations. Optical measurements perpendicular to the flow direction in the free jet showed significant contributions to the molecule emission through inverse pre-dissociation, thus allowing determination of atom number densities from molecular emission. This has been preliminarily demonstrated with the N2 1st Positive System. Despite the use of older rate coefficients, the resulting atom densities are reasonable and surprisingly close to flow predictions.

  9. Ensuring validity of radiometric temperature measurements obtained in the field using infrared imagers

    Mudau, AE

    2010-11-01

    Full Text Available When a military aircraft becomes the target of an approaching infrared seeker missile, it relies on infrared counter-measures to serve as decoys and to confuse the missile. The Optronic Sensor Systems (OSS) group at CSIR-DPSS is involved in computer...

  10. Radiometric modeling and calibration of the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) ground based measurement experiment

    Tian, Jialin; Smith, William L.; Gazarik, Michael J.

    2008-12-01

    The ultimate remote sensing benefits of the high resolution Infrared radiance spectrometers will be realized with their geostationary satellite implementation in the form of imaging spectrometers. This will enable dynamic features of the atmosphere's thermodynamic fields and pollutant and greenhouse gas constituents to be observed for revolutionary improvements in weather forecasts and more accurate air quality and climate predictions. As an important step toward realizing this application objective, the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstration Unit (EDU) was successfully developed under the NASA New Millennium Program, 2000-2006. The GIFTS-EDU instrument employs three focal plane arrays (FPAs), which gather measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The GIFTS calibration is achieved using internal blackbody calibration references at ambient (260 K) and hot (286 K) temperatures. In this paper, we introduce a refined calibration technique that utilizes Principle Component (PC) analysis to compensate for instrument distortions and artifacts, therefore, enhancing the absolute calibration accuracy. This method is applied to data collected during the GIFTS Ground Based Measurement (GBM) experiment, together with simultaneous observations by the accurately calibrated AERI (Atmospheric Emitted Radiance Interferometer), both simultaneously zenith viewing the sky through the same external scene mirror at ten-minute intervals throughout a cloudless day at Logan Utah on September 13, 2006. The accurately calibrated GIFTS radiances are produced using the first four PC scores in the GIFTS-AERI regression model. Temperature and moisture profiles retrieved from the PC-calibrated GIFTS radiances are verified against radiosonde measurements collected throughout the GIFTS sky measurement period. Using the GIFTS GBM calibration model, we compute the calibrated radiances from data

  11. Double modulation pyrometry: A radiometric method to measure surface temperatures of directly irradiated samples

    Potamias, Dimitrios; Alxneit, Ivo; Wokaun, Alexander

    2017-09-01

    The design, implementation, calibration, and assessment of double modulation pyrometry to measure surface temperatures of radiatively heated samples in our 1 kW imaging furnace is presented. The method requires that the intensity of the external radiation can be modulated. This was achieved by a rotating blade mounted parallel to the optical axis of the imaging furnace. Double modulation pyrometry independently measures the external radiation reflected by the sample as well as the sum of thermal and reflected radiation and extracts the thermal emission as the difference of these signals. Thus a two-step calibration is required: First, the relative gains of the measured signals are equalized and then a temperature calibration is performed. For the latter, we transfer the calibration from a calibrated solar blind pyrometer that operates at a different wavelength. We demonstrate that the worst case systematic error associated with this procedure is about 300 K but becomes negligible if a reasonable estimate of the sample's emissivity is used. An analysis of the influence of the uncertainties in the calibration coefficients reveals that one (out of the five) coefficient contributes almost 50% to the final temperature error. On a low emission sample like platinum, the lower detection limit is around 1700 K and the accuracy typically about 20 K. Note that these moderate specifications are specific for the use of double modulation pyrometry at the imaging furnace. It is mainly caused by the difficulty to achieve and maintain good overlap of the hot zone with a diameter of about 3 mm Full Width at Half Height and the measurement spot both of which are of similar size.

  12. Models for calibration of radiometric probes for measurement of natural radioactivity of rocks

    Czubek, J.A.; Lenda, A.

    1978-01-01

    The physical problems connected with the depth of investigation in the natural gamma-ray log measurements in the rocks are solved. The primary and the scattered radiation from gamma-ray lines of potassium, uranium and thorium series have been considered. The scattered radiation has been taken into account using the build-up factor approximation. The dimensions of rock models are calculated assuming the cylindrical form. Some recommendations for the realization of such models using the concrete mixtures are given. (author)

  13. Double modulation pyrometry: A radiometric method to measure surface temperatures of directly irradiated samples.

    Potamias, Dimitrios; Alxneit, Ivo; Wokaun, Alexander

    2017-09-01

    The design, implementation, calibration, and assessment of double modulation pyrometry to measure surface temperatures of radiatively heated samples in our 1 kW imaging furnace is presented. The method requires that the intensity of the external radiation can be modulated. This was achieved by a rotating blade mounted parallel to the optical axis of the imaging furnace. Double modulation pyrometry independently measures the external radiation reflected by the sample as well as the sum of thermal and reflected radiation and extracts the thermal emission as the difference of these signals. Thus a two-step calibration is required: First, the relative gains of the measured signals are equalized and then a temperature calibration is performed. For the latter, we transfer the calibration from a calibrated solar blind pyrometer that operates at a different wavelength. We demonstrate that the worst case systematic error associated with this procedure is about 300 K but becomes negligible if a reasonable estimate of the sample's emissivity is used. An analysis of the influence of the uncertainties in the calibration coefficients reveals that one (out of the five) coefficient contributes almost 50% to the final temperature error. On a low emission sample like platinum, the lower detection limit is around 1700 K and the accuracy typically about 20 K. Note that these moderate specifications are specific for the use of double modulation pyrometry at the imaging furnace. It is mainly caused by the difficulty to achieve and maintain good overlap of the hot zone with a diameter of about 3 mm Full Width at Half Height and the measurement spot both of which are of similar size.

  14. Determination of uranium in phosphorite by radiometric measurements and activation analysis

    Santos Amaral, R. dos.

    1987-01-01

    Uranium was determined by passive gamma ray counting in phosphate rocks in the range from 50 to 400 ppm U 3 O 8 . The measurements were carried out focusing on the 186 KeV gamma ray from the 235 U nuclide. The radioactive equilibrium of the 226 Ra in the uranium decay chain was investigated due its contribution in the 186 KeV compound 226 Ra 235 U photopeak. Therefore a simulataneous uranium determination through the 234 Th radionuclide demonstrate the equilibrium conditions. The results of the uranium analysis by the following methods: spectrophotometry, XRF and delayed neutrons from three independent laboratories were compared to evaluate the accuracy of the radioanalytical results. The uranium content was also determined by neutron activation analysis, followed by gamma measurement of the 239 Np formed by the 238 U (n,γ) 239 U reaction and 239 U beta decay and the fission products of 235 U. By the correlation of 239 Np, 99 Mo, 143 Ce, 131 I, and 133 I photopeak was measured the 238 U/ 235 U isotopic ratio. (author) [pt

  15. A Review of LIDAR Radiometric Processing: From Ad Hoc Intensity Correction to Rigorous Radiometric Calibration

    Alireza G. Kashani

    2015-11-01

    Full Text Available In addition to precise 3D coordinates, most light detection and ranging (LIDAR systems also record “intensity”, loosely defined as the strength of the backscattered echo for each measured point. To date, LIDAR intensity data have proven beneficial in a wide range of applications because they are related to surface parameters, such as reflectance. While numerous procedures have been introduced in the scientific literature, and even commercial software, to enhance the utility of intensity data through a variety of “normalization”, “correction”, or “calibration” techniques, the current situation is complicated by a lack of standardization, as well as confusing, inconsistent use of terminology. In this paper, we first provide an overview of basic principles of LIDAR intensity measurements and applications utilizing intensity information from terrestrial, airborne topographic, and airborne bathymetric LIDAR. Next, we review effective parameters on intensity measurements, basic theory, and current intensity processing methods. We define terminology adopted from the most commonly-used conventions based on a review of current literature. Finally, we identify topics in need of further research. Ultimately, the presented information helps lay the foundation for future standards and specifications for LIDAR radiometric calibration.

  16. A Review of LIDAR Radiometric Processing: From Ad Hoc Intensity Correction to Rigorous Radiometric Calibration.

    Kashani, Alireza G; Olsen, Michael J; Parrish, Christopher E; Wilson, Nicholas

    2015-11-06

    In addition to precise 3D coordinates, most light detection and ranging (LIDAR) systems also record "intensity", loosely defined as the strength of the backscattered echo for each measured point. To date, LIDAR intensity data have proven beneficial in a wide range of applications because they are related to surface parameters, such as reflectance. While numerous procedures have been introduced in the scientific literature, and even commercial software, to enhance the utility of intensity data through a variety of "normalization", "correction", or "calibration" techniques, the current situation is complicated by a lack of standardization, as well as confusing, inconsistent use of terminology. In this paper, we first provide an overview of basic principles of LIDAR intensity measurements and applications utilizing intensity information from terrestrial, airborne topographic, and airborne bathymetric LIDAR. Next, we review effective parameters on intensity measurements, basic theory, and current intensity processing methods. We define terminology adopted from the most commonly-used conventions based on a review of current literature. Finally, we identify topics in need of further research. Ultimately, the presented information helps lay the foundation for future standards and specifications for LIDAR radiometric calibration.

  17. Interpretation of UV radiometric measurements of spectrally non-uniform sources

    Murphy, P.J.; Gardner, D.G.

    1988-01-01

    Narrow bandpass UV radiometers are used in a variety of high-temperature measurement applications. Significant systematic errors, in the form of an apparent wavelength shift in the system response curve, may be introduced when interpreting data obtained from spectrally nonuniform sources. Theoretical calculations, using transmission curves from commercially available narrow bandpass filters, show that the apparent shift in the system spectral response is a function of temperature for a blackbody source. A brief comparison between the theoretical analysis and experimentaal data is presented

  18. Radiometric characterization of six soils in the microwave X-range through complex permittivity measurements

    Palme, U.W.

    1987-10-01

    Estimating and monitoring up-to-date soil moisture conditions over extensive areas through passive (or active) microwave remote sensing techniques requires the knowledge of the complex relative permittivity (ε r * ) in function of soil moisture. X-band measurements of ε r * for different moisture conditions were made in laboratory for soil samples of six important Soils (PV 2 , LV 3 , LR d , LE 1 , SAP and Sc). Using a theoretical model and computational programmes developed, these measurements allowed estimates of the emissive characteristics of the soils that would be expected with the X-Band Microwave Radiometer built at INPE. The results, new, for soils from tropical regions, showed that only the physical characteristics and properties of the soils are not sufficient to explain the behaviour of ε r * in function of soil moisture, indicating that the chemical and/or mineralogical properties of the soils do have an important contribution. The results also showed thast ε r * in function of soil moisture depends on soil class. (author) [pt

  19. Direct Reflectance Measurements from Drones: Sensor Absolute Radiometric Calibration and System Tests for Forest Reflectance Characterization

    Hakala, Teemu; Scott, Barry; Theocharous, Theo; Näsi, Roope; Suomalainen, Juha; Greenwell, Claire; Fox, Nigel

    2018-01-01

    Drone-based remote sensing has evolved rapidly in recent years. Miniaturized hyperspectral imaging sensors are becoming more common as they provide more abundant information of the object compared to traditional cameras. Reflectance is a physically defined object property and therefore often preferred output of the remote sensing data capture to be used in the further processes. Absolute calibration of the sensor provides a possibility for physical modelling of the imaging process and enables efficient procedures for reflectance correction. Our objective is to develop a method for direct reflectance measurements for drone-based remote sensing. It is based on an imaging spectrometer and irradiance spectrometer. This approach is highly attractive for many practical applications as it does not require in situ reflectance panels for converting the sensor radiance to ground reflectance factors. We performed SI-traceable spectral and radiance calibration of a tuneable Fabry-Pérot Interferometer -based (FPI) hyperspectral camera at the National Physical Laboratory NPL (Teddington, UK). The camera represents novel technology by collecting 2D format hyperspectral image cubes using time sequential spectral scanning principle. The radiance accuracy of different channels varied between ±4% when evaluated using independent test data, and linearity of the camera response was on average 0.9994. The spectral response calibration showed side peaks on several channels that were due to the multiple orders of interference of the FPI. The drone-based direct reflectance measurement system showed promising results with imagery collected over Wytham Forest (Oxford, UK). PMID:29751560

  20. Direct Reflectance Measurements from Drones: Sensor Absolute Radiometric Calibration and System Tests for Forest Reflectance Characterization.

    Hakala, Teemu; Markelin, Lauri; Honkavaara, Eija; Scott, Barry; Theocharous, Theo; Nevalainen, Olli; Näsi, Roope; Suomalainen, Juha; Viljanen, Niko; Greenwell, Claire; Fox, Nigel

    2018-05-03

    Drone-based remote sensing has evolved rapidly in recent years. Miniaturized hyperspectral imaging sensors are becoming more common as they provide more abundant information of the object compared to traditional cameras. Reflectance is a physically defined object property and therefore often preferred output of the remote sensing data capture to be used in the further processes. Absolute calibration of the sensor provides a possibility for physical modelling of the imaging process and enables efficient procedures for reflectance correction. Our objective is to develop a method for direct reflectance measurements for drone-based remote sensing. It is based on an imaging spectrometer and irradiance spectrometer. This approach is highly attractive for many practical applications as it does not require in situ reflectance panels for converting the sensor radiance to ground reflectance factors. We performed SI-traceable spectral and radiance calibration of a tuneable Fabry-Pérot Interferometer -based (FPI) hyperspectral camera at the National Physical Laboratory NPL (Teddington, UK). The camera represents novel technology by collecting 2D format hyperspectral image cubes using time sequential spectral scanning principle. The radiance accuracy of different channels varied between ±4% when evaluated using independent test data, and linearity of the camera response was on average 0.9994. The spectral response calibration showed side peaks on several channels that were due to the multiple orders of interference of the FPI. The drone-based direct reflectance measurement system showed promising results with imagery collected over Wytham Forest (Oxford, UK).

  1. Radiometric Measurements of the Thermal Conductivity of Complex Planetary-like Materials

    Piqueux, S.; Christensen, P. R.

    2012-12-01

    Planetary surface temperatures and thermal inertias are controlled by the physical and compositional characteristics of the surface layer material, which result from current and past geological activity. For this reason, temperature measurements are often acquired because they provide fundamental constraints on the geological history and habitability. Examples of regolith properties affecting surface temperatures and inertias are: grain sizes and mixture ratios, solid composition in the case of ices, presence of cement between grains, regolith porosity, grain roughness, material layering etc.. Other important factors include volatile phase changes, and endogenic or exogenic heat sources (i.e. geothermal heat flow, impact-related heat, biological activity etc.). In the case of Mars, the multitude of instruments observing the surface temperature at different spatial and temporal resolutions (i.e. IRTM, Thermoskan, TES, MiniTES, THEMIS, MCS, REMS, etc.) in conjunction with other instruments allows us to probe and characterize the thermal properties of the surface layer with an unprecedented resolution. While the derivation of thermal inertia values from temperature measurements is routinely performed by well-established planetary regolith numerical models, constraining the physical properties of the surface layer from thermal inertia values requires the additional step of laboratory measurements. The density and specific heat are usually constant and sufficiently well known for common geological materials, but the bulk thermal conductivity is highly variable as a function of the physical characteristics of the regolith. Most laboratory designs do not allow an investigation of the thermal conductivity of complex regolith configurations similar to those observed on planetary surfaces (i.e. cemented material, large grains, layered material, and temperature effects) because the samples are too small and need to be soft to insert heating or measuring devices. For this

  2. Method for Detection of Airborne UEs based on LTE Radio Measurements

    Wigard, Jeroen; Amorim, Rafhael Medeiros de; Nguyen, Huan Cong

    2017-01-01

    management can be optimized for UAVs separately from terrestrial UEs. In this paper, we present a classification algorithm using existing LTE UE radio measurements to identify whether a UE is airborne or terrestrial. The method is verified with LTE measurements made in a rural area at different heights......, including terrestrial measurements and it is shown that the method in 3 out of the 4 different measurement cases can detect a UE to be airborne with 99% likelihood, while the fourth case still can classify a UE correctly in 95% of the cases. The right classification can further be improved by taking...

  3. Hydrometeor discrimination in melting layer using multiparameter airborne radar measurement

    Kumagai, H.; Meneghini, R.; Kozu, T.

    1992-01-01

    Results from a multiparameter airborne radar/radiometer experiment (the Typhoon experiment) are presented. The experiment was conducted in the western Pacific with the NASA DC-8 aircraft, in which a dual-wavelength at X-band and Ka-band and dual-polarization at X-band radar was installed. The signatures of dBZ(X), dBZ(Ka), LDR (linear depolarization ratio) at X-band and DZ=dBZ(X)-dBZ(Ka) are discussed for the data obtained in the penetration of the typhoon Flo. With emphasis on discrimination of hydrometeor particles, some statistical features of the brightband in stratiform rain are discussed.

  4. A rigorous assessment of tree height measurements obtained using airborne LIDAR and conventional field methods.

    Hans-Erik Andersen; Stephen E. Reutebuch; Robert J. McGaughey

    2006-01-01

    Tree height is an important variable in forest inventory programs but is typically time-consuming and costly to measure in the field using conventional techniques. Airborne light detection and ranging (LIDAR) provides individual tree height measurements that are highly correlated with field-derived measurements, but the imprecision of conventional field techniques does...

  5. Environmental radiometric

    Gaeta C, R.

    1986-07-01

    This document stresses the importance of measuring the radioactivity of the environment in order to evaluate the radiological exposure of the population. The document emphasizes the necessity of detecting very low levels of radioactivity and the difficulties that it implies. The various components of its basis and the means for its reduction are mentioned. Information on the instruments required to identify and quantify the activities of the different radionuclides is given

  6. Measurement of airborne radon daughters - a Bayesian approach

    Groer, P.G.; Lo, Y.

    1997-01-01

    The standard mathematical treatment of the build-up and decay of airborne radionuclides on a filter paper uses the solutions of the so-called Bateman equations adapted to the sampling process. These equations can be interpreted as differential equations for the expectation of an underlying stochastic process, which describes the random fluctuations in the accumulation and decay of the sampled radioactive atoms. The probability distribution for the number of 218 Po, 214 Pb and 214 Bi atoms, accumulated after sampling time t, is the product of three Poisson distributions. It is shown that the distribution of the number of counts, registered by a detector with efficiency ε during a counting period T after the end of sampling, is also the product of three Poisson distributions. Its mean is dependent on ε, t, T, flow rate, and N A 0 , N B 0 and N C 0 , the number of 218 Po, 214 Pb and 214 Bi atoms per unit volume. This joint Poisson distribution was used to construct the likelihood given the observed number of counts. Using Bayes' Theorem posterior densities were obtained for N A 0 , N B 0 and N C 0 . These densities characterise the remaining uncertainty about the unknown airborne concentrations of 218 Po, 214 Pb and 214 Bi atoms. (author)

  7. Measurement of the sea surface wind speed and direction by an airborne microwave radar altimeter

    Nekrassov, A. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik

    2001-07-01

    A pilot needs operational information about wind over sea as well as wave height to provide safety of a hydroplane landing on water. Near-surface wind speed and direction can be obtained with an airborne microwave scatterometer, radar designed for measuring the scatter characteristics of a surface. Mostly narrow-beam antennas are applied for such wind measurement. Unfortunately, a microwave narrow-beam antenna has considerable size that hampers its placing on flying apparatus. In this connection, a possibility to apply a conventional airborne radar altimeter as a scatterometer with a nadir-looking wide-beam antenna in conjunction with Doppler filtering for recovering the wind vector over sea is discussed, and measuring algorithms of sea surface wind speed and direction are proposed. The obtained results can be used for creation of an airborne radar system for operational measurement of the sea roughness characteristics and for safe landing of a hydroplane on water. (orig.)

  8. Occupational exposure of phosphate mine workers: airborne radioactivity measurements and dose assessment

    Khater, Ashraf E.; Hussein, M.A.; Hussein, Mohamed I.

    2004-01-01

    Under the Egyptian program for radiation safety and control, airborne radioactivity measurements and radiological dose assessment were conducted in some phosphate and uranium mines. Abu-Tartor mine is one of the biggest underground phosphate mines in Egypt. Airborne radioactivity, radon ( 222 Rn) and its short-lived decay products (progenies) and thoron ( 220 Rn), were measured in selected locations along the mine. The environmental gamma and workers dose equivalent rate (mSv/y) were measured inside and outside the mine using thermo-luminescence dosimeters (TLD). The results were presented and discussed. The calculated annual effective dose due to airborne radioactivity is the main source of occupational exposure and exceeding the maximum recommended level by ICRP-60 inside the mine tunnels. A number of recommendations are suggested to control the occupational exposures

  9. Sun and aureole spectrometer for airborne measurements to derive aerosol optical properties.

    Asseng, Hagen; Ruhtz, Thomas; Fischer, Jürgen

    2004-04-01

    We have designed an airborne spectrometer system for the simultaneous measurement of the direct Sun irradiance and aureole radiance. The instrument is based on diffraction grating spectrometers with linear image sensors. It is robust, lightweight, compact, and reliable, characteristics that are important for airborne applications. The multispectral radiation measurements are used to derive optical properties of tropospheric aerosols. We extract the altitude dependence of the aerosol volume scattering function and of the aerosol optical depth by using flight patterns with descents and ascents ranging from the surface level to the top of the boundary layer. The extinction coefficient and the product of single scattering albedo and phase function of separate layers can be derived from the airborne measurements.

  10. The measurement of airborne rodon daughter concentrations in the atmosphere

    Ha, C.W.; Lee, J.K.; Moon, P.S.

    1979-01-01

    A simple method for determining the airborne concentration of radon daughter products has been developed, which is based on gross alpha counting of the air filter collections at several time intervals after completion of air sampling. The concentration of each nuclide is then obtained from an equation involving the alpha disintegrations, the sampling time, and the known numerical coefficients. The state of radioactive disequilibrium is also inventigated. The atmosphere sampled in the TRIGA Mark-III reactor room was largely in disequilibrium. The extent of radioactive disequilibrium between radon daughter products seems likely depend on sampling times associated with turbulence conditions. The data obtained here will certainly provide useful information on the evaluation of internal exposure and calibration of effluent monitoring instruments. (author)

  11. Machine-Learning Identification of Airborne UAV-UEs Based on LTE Radio Measurements

    Amorim, Rafhael Medeiros de; Wigard, Jeroen; Nguyen, Huan Cong

    2017-01-01

    , which use standard LTE measurements from the UE as input, for detecting the presence of airborne users in the network. The algorithms are evaluated based on measurements done with mobile phones attached under a flying drone and on a car. Results are discussed showing the advantages and drawbacks...

  12. Column CO2 Measurement From an Airborne Solid-State Double-Pulsed 2-Micron Integrated Path Differential Absorption Lidar

    Singh, U. N.; Yu, J.; Petros, M.; Refaat, T. F.; Remus, R.; Fay, J.; Reithmaier, K.

    2014-01-01

    NASA LaRC is developing and integrating a double-Pulsed 2-micron direct detection IPDA lidar for CO2 column measurement from an airborne platform. The presentation will describe the development of the 2-micrometers IPDA lidar system and present the airborne measurement of column CO2 and will compare to in-situ measurement for various ground target of different reflectivity.

  13. Radiometric surveys in underground environment

    Bochiolo, Massimo; Chiozzi, Paolo; Verdoya, Massimo; Pasquale, Vincenzo

    2010-05-01

    Due to their ability to travel through the air for several metres, gamma-rays emitted from natural radioactive elements can be successfully used in surveys carried out both with airborne and ground equipments. Besides the concentration of the radio-elements contained in rocks and soils and the intrinsic characteristics of the gamma-ray detector, the detected count rate depends on the solid angle around the spectrometer. On a flat outcrop, ground spectrometry detects the radiation ideally produced by a cylindrical mass of rock of about two metres in diameter and thickness of about half a meter. Under these geometrical conditions, the natural radioactivity can be easily evaluated. With operating conditions different from the standard ones, such as at the edge of an escarpment, the count rate halves because of the missing material, whereas in the vicinity of a rock wall the count rate will increase. In underground environment, the recorded count rate may even double and the in situ assessment of the concentration of radio-elements may be rather difficult, even if the ratios between the different radio-elements may not be affected. We tested the applicability of gamma-ray spectrometry for rapid assessment of the potential hazard levels related to radon and radiation dose rate in underground environment. A mine shaft, located in a zone of uranium enrichment in Liguria (Italy), has been investigated. A preliminary ground radiometric survey was carried out to define the extent of the ore deposit. Then, the radiometric investigation was focussed on the mine shaft. Due to rock mass above the shaft vault, the background gamma radiation can be considered of negligible influence on measurements. In underground surveys, besides deviations from a flat geometry, factors controlling radon exhalation, emanation and stagnation, such as fractures, water leakage and the presence of ventilation, should be carefully examined. We attempted to evaluate these control factors and collected

  14. Radiometric Normalization of Temporal Images Combining Automatic Detection of Pseudo-Invariant Features from the Distance and Similarity Spectral Measures, Density Scatterplot Analysis, and Robust Regression

    Ana Paula Ferreira de Carvalho

    2013-05-01

    Full Text Available Radiometric precision is difficult to maintain in orbital images due to several factors (atmospheric conditions, Earth-sun distance, detector calibration, illumination, and viewing angles. These unwanted effects must be removed for radiometric consistency among temporal images, leaving only land-leaving radiances, for optimum change detection. A variety of relative radiometric correction techniques were developed for the correction or rectification of images, of the same area, through use of reference targets whose reflectance do not change significantly with time, i.e., pseudo-invariant features (PIFs. This paper proposes a new technique for radiometric normalization, which uses three sequential methods for an accurate PIFs selection: spectral measures of temporal data (spectral distance and similarity, density scatter plot analysis (ridge method, and robust regression. The spectral measures used are the spectral angle (Spectral Angle Mapper, SAM, spectral correlation (Spectral Correlation Mapper, SCM, and Euclidean distance. The spectral measures between the spectra at times t1 and t2 and are calculated for each pixel. After classification using threshold values, it is possible to define points with the same spectral behavior, including PIFs. The distance and similarity measures are complementary and can be calculated together. The ridge method uses a density plot generated from images acquired on different dates for the selection of PIFs. In a density plot, the invariant pixels, together, form a high-density ridge, while variant pixels (clouds and land cover changes are spread, having low density, facilitating its exclusion. Finally, the selected PIFs are subjected to a robust regression (M-estimate between pairs of temporal bands for the detection and elimination of outliers, and to obtain the optimal linear equation for a given set of target points. The robust regression is insensitive to outliers, i.e., observation that appears to deviate

  15. Utilizing The Synergy of Airborne Backscatter Lidar and In-Situ Measurements for Evaluating CALIPSO

    Tsekeri Alexandra

    2016-01-01

    Full Text Available Airborne campaigns dedicated to satellite validation are crucial for the effective global aerosol monitoring. CALIPSO is currently the only active remote sensing satellite mission, acquiring the vertical profiles of the aerosol backscatter and extinction coefficients. Here we present a method for CALIPSO evaluation from combining lidar and in-situ airborne measurements. The limitations of the method have to do mainly with the in-situ instrumentation capabilities and the hydration modelling. We also discuss the future implementation of our method in the ICE-D campaign (Cape Verde, August 2015.

  16. Airborne Measurements in Support of the NASA Atmospheric Carbon and Transport - America (ACT-America) Mission

    Meadows, Byron; Davis, Ken; Barrick, John; Browell, Edward; Chen, Gao; Dobler, Jeremy; Fried, Alan; Lauvaux, Thomas; Lin, Bing; McGill, Matt; hide

    2015-01-01

    NASA announced the research opportunity Earth Venture Suborbital -2 (EVS-2) mission in support of the NASA's science strategic goals and objectives in 2013. Penn State University, NASA Langley Research Center (LaRC), and other academic institutions, government agencies, and industrial companies together formulated and proposed the Atmospheric Carbon and Transport -America (ACT -America) suborbital mission, which was subsequently selected for implementation. The airborne measurements that are part of ACT-America will provide a unique set of remote and in-situ measurements of CO2 over North America at spatial and temporal scales not previously available to the science community and this will greatly enhance our understanding of the carbon cycle. ACT -America will consist of five airborne campaigns, covering all four seasons, to measure regional atmospheric carbon distributions and to evaluate the accuracy of atmospheric transport models used to assess carbon sinks and sources under fair and stormy weather conditions. This coordinated mission will measure atmospheric carbon in the three most important regions of the continental US carbon balance: Northeast, Midwest, and South. Data will be collected using 2 airborne platforms (NASA Wallops' C-130 and NASA Langley's B-200) with both in-situ and lidar instruments, along with instrumented ground towers and under flights of the Orbiting Carbon Observatory (OCO-2) satellite. This presentation provides an overview of the ACT-America instruments, with particular emphasis on the airborne CO2and backscatter lidars, and the, rationale, approach, and anticipated results from this mission.

  17. Magnetic Approaches to Measuring and Mitigating Airborne Particulate Pollution

    Maher, B.

    2014-12-01

    Human exposure to airborne particulate matter (PM) generates adverse human health impacts at all life stages from the embryonic to the terminal, including damage to respiratory and cardiovascular health, and neurodevelopment and cognitive function. Detailed understanding of the causal links between PM exposure and specific health impacts, and possible means to reduce PM exposure require knowledge of PM concentrations, compositions and sources at the fine-scale; i.e. beyond the current resolution of spatially-sparse conventional PM monitoring, non-unique elemental analyses, or poorly-validated PM modelling. Magnetically-ordered iron oxide minerals appear to be a ubiquitous component of urban PM. These minerals derive partly from the presence of iron impurities in fuels, which form, upon combustion, a non-volatile residue, often dominated by magnetite, within glassy, spherical condensates. Iron-rich, magnetic PM also arises from abrasion from vehicle components, including disk brakes, and road dust. The ubiquity and diversity of these magnetic PM phases, and the speed and sensitivity of magnetic analyses (down to trace concentrations), makes possible rapid, cost-effective magnetic characterization and quantification of PM, a field of study which has developed rapidly across the globe over the last 2 decades. Magnetic studies of actively-sampled PM, on filters, and passively-sampled PM, on tree leaves and other depositional surfaces, can be used to: monitor and map at high spatial resolution ambient PM concentrations; address the controversial issue of the efficacy of PM capture by vegetation; and add a new, discriminatory dimension to PM source apportionment.

  18. The absolute calibration of KOMPSAT-3 and 3A high spatial resolution satellites using radiometric tarps and MFRSR measurments

    Yeom, J. M.

    2017-12-01

    Recently developed Korea Multi-Purpose Satellite-3A (KOMPSAT-3A), which is a continuation of the KOMPSAT-1, 2 and 3 earth observation satellite (EOS) programs from the Korea Aerospace Research Institute (KARI) was launched on March, 25 2015 on a Dnepr-1 launch vehicle from the Jasny Dombarovsky site in Russia. After launched, KARI performed in-orbit-test (IOT) including radiometric calibration for 6 months from 14 Apr. to 4 Sep. 2015. KOMPSAT-3A is equipped with two distinctive sensors; one is a high resolution multispectral optical sensor, namely the Advances Earth Image Sensor System-A (AEISS-A) and the other is the Scanner Infrared Imaging System (SIIS). In this study, we focused on the radiometric calibration of AEISS-A. The multispectral wavelengths of AEISS-A are covering three visible regions: blue (450 - 520 nm), green (520 - 600 nm), red (630 - 690 nm), one near infrared (760 - 900 nm) with a 2.0 m spatial resolution at nadir, whereas the panchromatic imagery (450 - 900 nm) has a 0.5 m resolution. Those are the same spectral response functions were same with KOMPSAT-3 multispectral and panchromatic bands but the spatial resolutions are improved. The main mission of KOMPSAT-3A is to develop for Geographical Information System (GIS) applications in environmental, agriculture, and oceanographic sciences, as well as natural hazard monitoring.

  19. Radiometric assays for glycerol, glucose, and glycogen

    Bradley, D.C.; Kaslow, H.R.

    1989-01-01

    We have developed radiometric assays for small quantities of glycerol, glucose and glycogen, based on a technique described by Thorner and Paulus for the measurement of glycerokinase activity. In the glycerol assay, glycerol is phosphorylated with [32P]ATP and glycerokinase, residual [32P]ATP is hydrolyzed by heating in acid, and free [32P]phosphate is removed by precipitation with ammonium molybdate and triethylamine. Standard dose-response curves were linear from 50 to 3000 pmol glycerol with less than 3% SD in triplicate measurements. Of the substances tested for interference, only dihydroxyacetone gave a slight false positive signal at high concentration. When used to measure glycerol concentrations in serum and in media from incubated adipose tissue, the radiometric glycerol assay correlated well with a commonly used spectrophotometric assay. The radiometric glucose assay is similar to the glycerol assay, except that glucokinase is used instead of glycerokinase. Dose response was linear from 5 to 3000 pmol glucose with less than 3% SD in triplicate measurements. Glucosamine and N-acetylglucosamine gave false positive signals when equimolar to glucose. When glucose concentrations in serum were measured, the radiometric glucose assay agreed well with hexokinase/glucose-6-phosphate dehydrogenase (H/GDH)-based and glucose oxidase/H2O2-based glucose assays. The radiometric method for glycogen measurement incorporates previously described isolation and digestion techniques, followed by the radiometric assay of free glucose. When used to measure glycogen in mouse epididymal fat pads, the radiometric glycogen assay correlated well with the H/GDH-based glycogen assay. All three radiometric assays offer several practical advantages over spectral assays

  20. Transmission of Airborne Bacteria across Built Environments and Its Measurement Standards: A Review.

    Fujiyoshi, So; Tanaka, Daisuke; Maruyama, Fumito

    2017-01-01

    Human health is influenced by various factors including microorganisms present in built environments where people spend most of their lives (approximately 90%). It is therefore necessary to monitor and control indoor airborne microbes for occupational safety and public health. Most studies concerning airborne microorganisms have focused on fungi, with scant data available concerning bacteria. The present review considers papers published from 2010 to 2017 approximately and factors affecting properties of indoor airborne bacteria (communities and concentration) with respect to temporal perspective and to multiscale interaction viewpoint. From a temporal perspective, bacterial concentrations in built environments change depending on numbers of human occupancy, while properties of bacterial communities tend to remain stable. Similarly, the bacteria found in social and community spaces such as offices, classrooms and hospitals are mainly associated with human occupancy. Other major sources of indoor airborne bacteria are (i) outdoor environments, and (ii) the building materials themselves. Indoor bacterial communities and concentrations are varied with varying interferences by outdoor environment. Airborne bacteria from the outdoor environment enter an indoor space through open doors and windows, while indoor bacteria are simultaneously released to the outer environment. Outdoor bacterial communities and their concentrations are also affected by geographical factors such as types of land use and their spatial distribution. The bacteria found in built environments therefore originate from any of the natural and man-made surroundings around humans. Therefore, to better understand the factors influencing bacterial concentrations and communities in built environments, we should study all the environments that humans contact as a single ecosystem. In this review, we propose the establishment of a standard procedure for assessing properties of indoor airborne bacteria using

  1. Transmission of Airborne Bacteria across Built Environments and Its Measurement Standards: A Review

    So Fujiyoshi

    2017-11-01

    Full Text Available Human health is influenced by various factors including microorganisms present in built environments where people spend most of their lives (approximately 90%. It is therefore necessary to monitor and control indoor airborne microbes for occupational safety and public health. Most studies concerning airborne microorganisms have focused on fungi, with scant data available concerning bacteria. The present review considers papers published from 2010 to 2017 approximately and factors affecting properties of indoor airborne bacteria (communities and concentration with respect to temporal perspective and to multiscale interaction viewpoint. From a temporal perspective, bacterial concentrations in built environments change depending on numbers of human occupancy, while properties of bacterial communities tend to remain stable. Similarly, the bacteria found in social and community spaces such as offices, classrooms and hospitals are mainly associated with human occupancy. Other major sources of indoor airborne bacteria are (i outdoor environments, and (ii the building materials themselves. Indoor bacterial communities and concentrations are varied with varying interferences by outdoor environment. Airborne bacteria from the outdoor environment enter an indoor space through open doors and windows, while indoor bacteria are simultaneously released to the outer environment. Outdoor bacterial communities and their concentrations are also affected by geographical factors such as types of land use and their spatial distribution. The bacteria found in built environments therefore originate from any of the natural and man-made surroundings around humans. Therefore, to better understand the factors influencing bacterial concentrations and communities in built environments, we should study all the environments that humans contact as a single ecosystem. In this review, we propose the establishment of a standard procedure for assessing properties of indoor airborne

  2. Analysis of measured L-band airborne land clutter from the Western Cape region of South Africa

    De Witt, JJ

    2014-10-01

    Full Text Available -band Airborne Land Clutter from the Western Cape region of South Africa J.J. de Witt and J.J. Strydom Abstract: This paper presents backscatter analysis of L-band land clutter data, measured from an airborne platform, over various terrain types...

  3. Assessment of water pollution by airborne measurement of chlorophyll

    Arvesen, J. C.; Weaver, E. C.; Millard, J. P.

    1972-01-01

    Remote measurement of chlorophyll concentrations to determine extent of water pollution is discussed. Construction and operation of radiometer to provide measurement capability are explained. Diagram of equipment is provided.

  4. Airborne 2-Micron Double-Pulsed Integrated Path Differential Absorption Lidar for Column CO2 Measurement

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Remus, Ruben G.; Fay, James J.; Reithmaier, Karl

    2014-01-01

    Double-pulse 2-micron lasers have been demonstrated with energy as high as 600 millijouls and up to 10 Hz repetition rate. The two laser pulses are separated by 200 microseconds and can be tuned and locked separately. Applying double-pulse laser in DIAL system enhances the CO2 measurement capability by increasing the overlap of the sampled volume between the on-line and off-line. To avoid detection complicity, integrated path differential absorption (IPDA) lidar provides higher signal-to-noise ratio measurement compared to conventional range-resolved DIAL. Rather than weak atmospheric scattering returns, IPDA rely on the much stronger hard target returns that is best suited for airborne platforms. In addition, the IPDA technique measures the total integrated column content from the instrument to the hard target but with weighting that can be tuned by the transmitter. Therefore, the transmitter could be tuned to weight the column measurement to the surface for optimum CO2 interaction studies or up to the free troposphere for optimum transport studies. Currently, NASA LaRC is developing and integrating a double-Pulsed 2-micron direct detection IPDA lidar for CO2 column measurement from an airborne platform. The presentation will describe the development of the 2-micron IPDA lidar system and present the airborne measurement of column CO2 and will compare to in-situ measurement for various ground target of different reflectivity.

  5. All-Fiber Airborne Coherent Doppler Lidar to Measure Wind Profiles

    Liu Jiqiao

    2016-01-01

    Full Text Available An all-fiber airborne pulsed coherent Doppler lidar (CDL prototype at 1.54μm is developed to measure wind profiles in the lower troposphere layer. The all-fiber single frequency pulsed laser is operated with pulse energy of 300μJ, pulse width of 400ns and pulse repetition rate of 10kHz. To the best of our knowledge, it is the highest pulse energy of all-fiber eye-safe single frequency laser that is used in airborne coherent wind lidar. The telescope optical diameter of monostatic lidar is 100 mm. Velocity-Azimuth-Display (VAD scanning is implemented with 20 degrees elevation angle in 8 different azimuths. Real-time signal processing board is developed to acquire and process the heterodyne mixing signal with 10000 pulses spectra accumulated every second. Wind profiles are obtained every 20 seconds. Several experiments are implemented to evaluate the performance of the lidar. We have carried out airborne wind lidar experiments successfully, and the wind profiles are compared with aerological theodolite and ground based wind lidar. Wind speed standard error of less than 0.4m/s is shown between airborne wind lidar and balloon aerological theodolite.

  6. The Pelindaba facility for calibrating radiometric field instruments

    Corner, B.; Toens, P.D.; Van As, D.; Vleggaar, C.M.; Richards, D.J.

    1979-04-01

    The tremendous upsurge in uranium exploration activity, experienced in recent years, has made the need for the standardisation and calibration of radiometric field instruments apparent. In order to fulfill this need, construction of a calibration facility at the National Nuclear Research Centre, Pelindaba, was commenced in 1972 and has since been extended according the the requirements of the mining industry. The facility currently comprises 11 surface standard sources suitable for the calibration, in terms of radio-element concentration, of portable scintillometers and spectrometers, and single uranium and thorium model-borehole sources which make possible the accurate calibration of borehole logging instruments both for gross-count and spectrometric surveys. Portable potassium, uranium and thorium sources are also available for the purposes of establishing airborne-spectrometer stripping ratios. The relevant physico-chemical properties of the standards are presented in this report and calibration procedures and data reduction techniques recommended. Examples are given of in situ measurements, both on surface and down-the-hole, which show that the derived calibration constants yield radiometric grades which are, on average, accurate to within 5% of the true radio-element concentrations. A secondary facility comprising single borehole- and surface-uranium sources has also been constructed in Beaufort West in the southern Karoo [af

  7. Instrument for Airborne Measurement of Carbonyl Sulfide, Phase I

    National Aeronautics and Space Administration — Southwest Sciences proposes to develop small, low power instrumentation for the real-time direct measurement of carbonyl sulfide (OCS) in the atmosphere, especially...

  8. Instrument for Airborne Measurement of Carbonyl Sulfide, Phase II

    National Aeronautics and Space Administration — In this Phase II SBIR program, Southwest Sciences will continue the development of small, low power instrumentation for real-time direct measurement of carbonyl...

  9. King George Island ice cap geometry updated with airborne GPR measurements

    M. Rückamp

    2012-07-01

    Full Text Available Ice geometry is a mandatory requirement for numerical modelling purposes. In this paper we present a consistent data set for the ice thickness, the bedrock topography and the ice surface topography of the King George Island ice cap (Arctowski icefield and the adjacent central part. The new data set is composed of ground based and airborne ground penetrating radar (GPR and differential GPS (DGPS measurements, obtained during several field campaigns. Blindow et al. (2010 already provided a comprehensive overview of the ground based measurements carried out in the safely accessible area of the ice cap. The updated data set incorporates airborne measurements in the heavily crevassed coastal areas. Therefore, in this paper special attention is paid to the airborne measurements by addressing the instrument used, survey procedure, and data processing in more detail. In particular, the inclusion of airborne GPR measurements with the 30 MHz BGR-P30-System developed at the Institute of Geophysics (University of Münster completes the picture of the ice geometry substantially. The compiled digital elevation model of the bedrock shows a rough, highly variable topography with pronounced valleys, ridges, and troughs. Mean ice thickness is 240 ± 6 m, with a maximum value of 422 ± 10 m in the surveyed area. Noticeable are bounded areas in the bedrock topography below sea level where marine based ice exists. The provided data set is required as a basis for future monitoring attempts or as input for numerical modelling experiments. The data set is available from the PANGAEA database at http://dx.doi.org/10.1594/PANGAEA.770567.

  10. Evaluating the capabilities of portable black carbon monitors and photometers for measuring airborne carbon nanotubes

    Hashimoto, Naomi; Ogura, Isamu, E-mail: i-ogura@aist.go.jp; Kotake, Mari; Kishimoto, Atsuo; Honda, Kazumasa [Technology Research Association for Single Wall Carbon Nanotubes (TASC) (Japan)

    2013-11-15

    For daily monitoring of occupational exposure to aerosolized carbon nanotubes (CNTs) where CNTs are manufactured and handled, inexpensive real-time measuring methods are preferable. In this study, we evaluated the capabilities of a portable black carbon monitor (BCM; also called an aethalometer) and a light-scattering aerosol photometer in detecting airborne CNTs. The responses of these instruments to airborne CNTs, aerosolized through vortex shaking, were evaluated by comparing the measurements of CNT mass concentrations made by these instruments to those determined through thermal carbon analysis. Results showed that their raw readings underestimated CNT mass concentrations in most cases. Their sensitivities depended on the type of CNTs and decreased with the particle sizes of aerosolized CNT clumps. We also found that the sensitivity of the BCM tended to substantially decrease with increasing filter load, even before the point at which the filter should be replaced as recommended by the manufacturer, which could be attributed to a clean environmental condition (i.e., the absence of ubiquitous light-scattering material). As an example of the use of these instruments for measuring airborne CNTs in the presence of background aerosols, a CNT-handling simulation was also conducted. Although both the BCM and the photometer could detect CNT emissions, the BCM was more sensitive to the detection of emitted CNTs in the presence of background aerosols. The correction factors obtained from the response evaluations could enhance the measurement accuracy of these instruments, which will be helpful for the daily monitoring of CNTs at workplaces.

  11. Evaluating the capabilities of portable black carbon monitors and photometers for measuring airborne carbon nanotubes

    Hashimoto, Naomi; Ogura, Isamu; Kotake, Mari; Kishimoto, Atsuo; Honda, Kazumasa

    2013-01-01

    For daily monitoring of occupational exposure to aerosolized carbon nanotubes (CNTs) where CNTs are manufactured and handled, inexpensive real-time measuring methods are preferable. In this study, we evaluated the capabilities of a portable black carbon monitor (BCM; also called an aethalometer) and a light-scattering aerosol photometer in detecting airborne CNTs. The responses of these instruments to airborne CNTs, aerosolized through vortex shaking, were evaluated by comparing the measurements of CNT mass concentrations made by these instruments to those determined through thermal carbon analysis. Results showed that their raw readings underestimated CNT mass concentrations in most cases. Their sensitivities depended on the type of CNTs and decreased with the particle sizes of aerosolized CNT clumps. We also found that the sensitivity of the BCM tended to substantially decrease with increasing filter load, even before the point at which the filter should be replaced as recommended by the manufacturer, which could be attributed to a clean environmental condition (i.e., the absence of ubiquitous light-scattering material). As an example of the use of these instruments for measuring airborne CNTs in the presence of background aerosols, a CNT-handling simulation was also conducted. Although both the BCM and the photometer could detect CNT emissions, the BCM was more sensitive to the detection of emitted CNTs in the presence of background aerosols. The correction factors obtained from the response evaluations could enhance the measurement accuracy of these instruments, which will be helpful for the daily monitoring of CNTs at workplaces

  12. Radon emanation and soil moisture effects on airborne gamma-ray measurements

    Grasty, R.L.

    1997-01-01

    A theoretical model is developed to explain variations in airborne gamma-ray measurements over a calibration range near Ottawa, Ontario. The gamma-ray flux from potassium and the thorium decay series showed an expected decrease with increasing soil moisture. However, the gamma-ray flux from the uranium decay series was highest in the spring when the ground was water-saturated and even covered with snow. These results are explained through the build-up of radon and its associated gamma-ray-emitting decay products in the clay soil of the calibration range with increasing soil moisture. Similar results were found from airborne measurements over other clay soils. However, measurements over sandy soils showed that the count rates from all three radio elements increased with decreasing soil moisture. This difference between soil types was attributed to the lower radon emanation of the more coarse-grained sandy soils compared to finer-grained clay soils. The theoretical and experimental results demonstrate that any estimate of the natural gamma-ray field caused by radium in the ground must take into consideration the radon emanation coefficient of the soil. The radon diffusion coefficient of the soil must also be considered since it depends strongly on soil moisture. This has significant implications for the assessment of outdoor radiation doses using laboratory analyses of soil samples and the use of ground and airborne gamma-ray measurements for radon potential mapping

  13. Dis-aggregation of airborne flux measurements using footprint analysis

    Hutjes, R.W.A.; Vellinga, O.S.; Gioli, B.; Miglietta, F.

    2010-01-01

    Aircraft measurements of turbulent fluxes are generally being made with the objective to obtain an estimate of regional exchanges between land surface and atmosphere, to investigate the spatial variability of these fluxes, but also to learn something about the fluxes from some or all of the land

  14. Airborne Gamma-ray Measurements in the Chernobyl Plume

    Grasty, R. L.; Hovgaard, Jens; Multala, J.

    1997-01-01

    On 29 April 1986, the Geological Survey of Finland (GSF) survey aircraft with a gamma ray spectrometer flew through a radioactive plume from the Chernobyl nuclear accident. The aircraft became contaminated and the gamma spectrometer measured radioactivity in the plume as well as radioactivity...

  15. Airborne lidar measurements of the Soufriere eruption of 17 April 1979

    Fuller, W. H., Jr.; Sokol, S.; Hunt, W. H.

    1982-01-01

    At the time of the Soufriere, St. Vincent, volcanic eruption of April 17, 1979, a NASA P-3 aircraft with an uplooking lidar (light detection and ranging) system onboard was airborne 130 kilometers east of the island. Lidar measurements of the fresh volcanic ash were made approximately 2 hours after the eruption, 120 kilometers to the northeast and east. On the evening of April 18, the airborne lidar, on a southerly flight track, detected significant amounts of stratospheric material in layers at 16, 17, 18, and 19.5 kilometers. These data, and measurements to the north on April 19, indicate that the volcanic plume penetrated the stratosphere to an altitude of about 20 kilometers and moved south during the first 48 hours after the eruption.

  16. Airborne spectral measurements of surface anisotropy during SCAR-B

    Tsay, Si-Chee; King, Michael D.; Arnold, G. Thomas; Li, Jason Y.

    1998-12-01

    During the Smoke, Clouds, and Radiation-Brazil (SCAR-B) deployment, angular distributions of spectral reflectance for vegetated surfaces and smoke layers were measured using the scanning cloud absorption radiometer (CAR) mounted on the University of Washington C-131A research aircraft. The CAR contains 13 narrowband spectral channels between 0.3 and 2.3 μm with a 190° scan aperture (5° before zenith to 5° past nadir) and 1° instantaneous field of view. The bidirectional reflectance is obtained by flying a clockwise circular orbit above the surface, resulting in a ground track ˜3 km in diameter within about 2 min. Although the CAR measurements are contaminated by minor atmospheric effects, results show distinct spectral characteristics for various types of surfaces. Spectral bidirectional reflectances of three simple and well-defined surfaces are presented: cerrado (August 18, 1995) and dense forest (August 25, 1995), both measured in Brazil under nearly clear-sky conditions, and thick smoke layers over dense forest (September 6 and 11, 1995). The bidirectional reflectances of cerrado and dense forest revealed fairly symmetric patterns along the principal plane, with varying maximal strengths and widths spectrally in the backscattering direction. In the shortwave-infrared region the aerosol effect is very small due to low spectral optical depth. Also, these backscattering maxima can be seen on the bidirectional reflectance of smoke layer over dense forest. These detailed measurements of the angular distribution of spectral reflectance can be parameterized by a few independent variables and utilized to retrieve either surface characteristics or aerosol microphysical and optical properties (e.g., size distribution and single-scattering parameters), if proper physical and radiation models are used. The spectral-hemispherical albedo of these surfaces is obtained directly by integrating all angular measurements and is compared with the measured nadir reflectance

  17. Elucidating Carbon Exchange at the Regional Scale Via Airborne Eddy Covariance Flux Measurements

    Hannun, R. A.; Wolfe, G. M.; Kawa, S. R.; Newman, P. A.; Hanisco, T. F.; Diskin, G. S.; DiGangi, J. P.; Nowak, J. B.; Barrick, J. D. W.; Thornhill, K. L., II; Noormets, A.; Vargas, R.; Clark, K. L.; Kustas, W. P.

    2017-12-01

    Direct flux observations from aircraft provide a unique tool for probing greenhouse gas (GHG) sources and sinks on a regional scale. Airborne eddy covariance, which relies on high-frequency, simultaneous measurements of fluctuations in concentration and vertical wind speed, is a robust method for quantifying surface-atmosphere exchange. We have assembled and flown an instrument payload onboard the NASA C-23 Sherpa aircraft capable of measuring CO2, CH4, H2O, and heat fluxes. Flights for the Carbon Airborne Flux Experiment (CARAFE) took place during September 2016 and May 2017 based out of Wallops Flight Facility, VA. Flight tracks covered a variety of ecosystems and land-use types in the Mid-Atlantic, including forests, croplands, and wetlands. Carbon fluxes are derived using eddy covariance and wavelet analysis. Our results show a strong drawdown of CO2 and near-zero CH4 emissions from crops and dry-land forest, but seasonally strong CH4 flux from wetland forest. CARAFE flux data will also be compared with observations from several flux towers along the flight path to complement the airborne measurements. We will further assess the effects of land surface type and seasonal variability in carbon exchange. Regional-scale flux observations from CARAFE supply a useful constraint for improving top-down and bottom up estimates of carbon sources and sinks.

  18. Airborne direct-detection and coherent wind lidar measurements over the North Atlantic in 2015 supporting ESA's aeolus mission

    Marksteiner, Uwe; Reitebuch, Oliver; Lemmerz, Christian; Lux, Oliver; Rahm, Stephan; Witschas, Benjamin; Schäfler, Andreas; Emmitt, Dave; Greco, Steve; Kavaya, Michael J.; Gentry, Bruce; Neely, Ryan R.; Kendall, Emma; Schüttemeyer, Dirk

    2018-04-01

    The launch of the Aeolus mission by the European Space Agency (ESA) is planned for 2018. The satellite will carry the first wind lidar in space, ALADIN (Atmospheric Laser Doppler INstrument). Its prototype instrument, the ALADIN Airborne Demonstrator (A2D), was deployed during several airborne campaigns aiming at the validation of the measurement principle and optimization of algorithms. In 2015, flights of two aircraft from DLR & NASA provided the chance to compare parallel wind measurements from four airborne wind lidars for the first time.

  19. Validation of Airborne FMCW Radar Measurements of Snow Thickness Over Sea Ice in Antarctica

    Galin, Natalia; Worby, Anthony; Markus, Thorsten; Leuschen, Carl; Gogineni, Prasad

    2012-01-01

    Antarctic sea ice and its snow cover are integral components of the global climate system, yet many aspects of their vertical dimensions are poorly understood, making their representation in global climate models poor. Remote sensing is the key to monitoring the dynamic nature of sea ice and its snow cover. Reliable and accurate snow thickness data are currently a highly sought after data product. Remotely sensed snow thickness measurements can provide an indication of precipitation levels, predicted to increase with effects of climate change in the polar regions. Airborne techniques provide a means for regional-scale estimation of snow depth and distribution. Accurate regional-scale snow thickness data will also facilitate an increase in the accuracy of sea ice thickness retrieval from satellite altimeter freeboard estimates. The airborne data sets are easier to validate with in situ measurements and are better suited to validating satellite algorithms when compared with in situ techniques. This is primarily due to two factors: better chance of getting coincident in situ and airborne data sets and the tractability of comparison between an in situ data set and the airborne data set averaged over the footprint of the antennas. A 28-GHz frequency modulated continuous wave (FMCW) radar loaned by the Center for Remote Sensing of Ice Sheets to the Australian Antarctic Division is used to measure snow thickness over sea ice in East Antarctica. Provided with the radar design parameters, the expected performance parameters of the radar are summarized. The necessary conditions for unambiguous identification of the airsnow and snowice layers for the radar are presented. Roughnesses of the snow and ice surfaces are found to be dominant determinants in the effectiveness of layer identification for this radar. Finally, this paper presents the first in situ validated snow thickness estimates over sea ice in Antarctica derived from an FMCW radar on a helicopterborne platform.

  20. An Ultralow Power Fast-Response Nano-TCD CH4 sensor for UAV Airborne Measurements, Phase I

    National Aeronautics and Space Administration — In this project, KWJ proposes to develop a low power, fast response, lightweight miniature CH4 measurement system based on KWJ nano-TCD sensor for airborne...

  1. Rapid assessment of water pollution by airborne measurement of chlorophyll content.

    Arvesen, J. C.; Weaver, E. C.; Millard, J. P.

    1971-01-01

    Present techniques of airborne chlorophyll measurement are discussed as an approach to water pollution assessment. The differential radiometer, the chlorophyll correlation radiometer, and an infrared radiometer for water temperature measurements are described as the key components of the equipment. Also covered are flight missions carried out to evaluate the capability of the chlorophyll correlation radiometer in measuring the chlorophyll content in water bodies with widely different levels of nutrients, such as fresh-water lakes of high and low eutrophic levels, marine waters of high and low productivity, and an estuary with a high sediment content. The feasibility and usefulness of these techniques are indicated.

  2. Airborne measurements of NO{sub y} and impact of this trace gas on atmospheric chemistry

    Perros, P E; Marion, T [Paris-12 et 7 Univ., Laboratoire Interuniversitaire des Systemes Atmospheriques, 94 - Creteil (France)

    1999-05-01

    Nitrogen compounds play a key role in the ozone production processes. The airborne measurement of individual species is difficult compared to their global measurement. This can be done by the conversion of all the species (NO{sub y}) in NO followed by a subsequent analysis by chemiluminescence. Laboratory tests allow up to determine the main characteristics of such conversion. NO{sub y} measurements associated with NO{sub x} concentrations allow a quantitative and qualitative study of ozone production processes. In particular it is possible to determine the ozone production potential of an air mass, the ozone production efficiency and to specify the chemical regimes. (authors) 13 refs.

  3. Airborne Two-Micron Double-Pulse IPDA Lidar Validation for Carbon Dioxide Measurements Over Land

    Refaat, Tamer F.; Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Remus, Ruben; Ismail, Syed

    2018-04-01

    An airborne double-pulse 2-μm Integrated Path Differential Absorption (IPDA) lidar has been developed at NASA LaRC for measuring atmospheric CO2. IPDA was validated using NASA B-200 aircraft over land and ocean under different conditions. IPDA evaluation for land vegetation returns, during full day background conditions, are presented. IPDA CO2 measurements compare well with model results driven from on-board insitu sensor data. These results also indicate that CO2 measurement bias is consistent with that from ocean surface returns.

  4. Airborne radon-222 measurement by active sampling with charcoal adsorption and gamma-ray spectrometry

    Shizuma, Kiyoshi; Wen, Xiao-qiong; Fukami, Kenji; Iwatani, Kazuo; Hamanaka, Shun-ichi

    1998-01-01

    A simple method for measuring radon concentration in air is presented. Airborne radon is adsorbed in a charcoal bed by an active air sampling. In time, the adsorbed radon comes to attain radioactive equilibrium with its short-lived progeny 214 Pb. Utilizing this fact, radon concentration is derived from γ-ray measurement of 214 Pb. This method is estimated to be capable of detecting radon concentration in air down to 0.79 Bq·m -3 . The adsorption coefficient obtained with the method is compared with what is obtainable with passive sampling. Applications of this method to indoor and outdoor radon measurements are described. (author)

  5. Potential of remote sensing of cirrus optical thickness by airborne spectral radiance measurements at different sideward viewing angles

    Wolf, Kevin; Ehrlich, André; Hüneke, Tilman; Pfeilsticker, Klaus; Werner, Frank; Wirth, Martin; Wendisch, Manfred

    2017-01-01

    Spectral radiance measurements collected in nadir and sideward viewing directions by two airborne passive solar remote sensing instruments, the Spectral Modular Airborne Radiation measurement sysTem (SMART) and the Differential Optical Absorption Spectrometer (mini-DOAS), are used to compare the remote sensing results of cirrus optical thickness τ. The comparison is based on a sensitivity study using radiative transfer simulations (RTS) and on data obtained during three airb...

  6. Airborne and Ground-Based Measurements Using a High-Performance Raman Lidar

    Whiteman, David N.; Rush, Kurt; Rabenhorst, Scott; Welch, Wayne; Cadirola, Martin; McIntire, Gerry; Russo, Felicita; Adam, Mariana; Venable, Demetrius; Connell, Rasheen; hide

    2010-01-01

    A high-performance Raman lidar operating in the UV portion of the spectrum has been used to acquire, for the first time using a single lidar, simultaneous airborne profiles of the water vapor mixing ratio, aerosol backscatter, aerosol extinction, aerosol depolarization and research mode measurements of cloud liquid water, cloud droplet radius, and number density. The Raman Airborne Spectroscopic Lidar (RASL) system was installed in a Beechcraft King Air B200 aircraft and was flown over the mid-Atlantic United States during July August 2007 at altitudes ranging between 5 and 8 km. During these flights, despite suboptimal laser performance and subaperture use of the telescope, all RASL measurement expectations were met, except that of aerosol extinction. Following the Water Vapor Validation Experiment Satellite/Sondes (WAVES_2007) field campaign in the summer of 2007, RASL was installed in a mobile trailer for groundbased use during the Measurements of Humidity and Validation Experiment (MOHAVE-II) field campaign held during October 2007 at the Jet Propulsion Laboratory s Table Mountain Facility in southern California. This ground-based configuration of the lidar hardware is called Atmospheric Lidar for Validation, Interagency Collaboration and Education (ALVICE). During theMOHAVE-II field campaign, during which only nighttime measurements were made, ALVICE demonstrated significant sensitivity to lower-stratospheric water vapor. Numerical simulation and comparisons with a cryogenic frost-point hygrometer are used to demonstrate that a system with the performance characteristics of RASL ALVICE should indeed be able to quantify water vapor well into the lower stratosphere with extended averaging from an elevated location like Table Mountain. The same design considerations that optimize Raman lidar for airborne use on a small research aircraft are, therefore, shown to yield significant dividends in the quantification of lower-stratospheric water vapor. The MOHAVE

  7. Radiometric calipers for borehole logging

    Charbucinski, J.; Wylie, A.W.; Jarrett, R.G.

    1976-01-01

    Two versions of a radiometric-type caliper for measuring borehole diameter are described. One, based on the bow-spring principle, is suitable for percussion (exploration) drill holes. The other, which utilizes hemispherical wall contactors actuated by springs, is suitable for blast holes. Both utilize low-power radioactive sources and employ a scintillation detector to measure the 'inverse-square law' response of the device to changes in borehole radius. The performance of the device is examined and examples of its use are illustrated. (author)

  8. Airborne methane remote measurements reveal heavy-tail flux distribution in Four Corners region.

    Frankenberg, C.

    2016-12-01

    Methane (CH4) impacts climate as the second strongest anthropogenic greenhouse gas and air quality by influencing tropospheric ozone levels. Space-based observations have identified the Four Corners region in the Southwest United States as an area of large CH4 enhancements. We conducted an airborne campaign in Four Corners during April 2015 with the next-generation Airborne Visible/Infrared Imaging Spectrometer (near-infrared) and Hyperspectral Thermal Emission Spectrometer (thermal infrared) imaging spectrometers to better understand the source of methane by measuring methane plumes at 1- to 3-m spatial resolution. Our analysis detected more than 250 individual methane plumes from fossil fuel harvesting, processing, and distributing infrastructures, spanning an emission range from the detection limit ˜ 2 kg/h to 5 kg/h through ˜ 5,000 kg/h. Observed sources include gas processing facilities, storage tanks, pipeline leaks, natural seeps and well pads, as well as a coal mine venting shaft. Overall, plume enhancements and inferred fluxes follow a lognormal distribution, with the top 10% emitters contributing 49 to 66% to the inferred total point source flux of 0.23 Tg/y to 0.39 Tg/y. We will summarize the campaign results and provide an overview of how airborne remote sensing can be used to detect and infer methane fluxes over widespread geographic areas and how new instrumentation could be used to perform similar observations from space.

  9. Determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using radiochemical separation combined with radiometric and mass spectrometric measurements.

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin; Pan, Shaoming; Roos, Per

    2014-02-01

    This paper reports an analytical method for the determination of plutonium isotopes ((238)Pu, (239)Pu, (240)Pu, (241)Pu) in environmental samples using anion exchange chromatography in combination with extraction chromatography for chemical separation of Pu. Both radiometric methods (liquid scintillation counting and alpha spectrometry) and inductively coupled plasma mass spectrometry (ICP-MS) were applied for the measurement of plutonium isotopes. The decontamination factors for uranium were significantly improved up to 7.5 × 10(5) for 20 g soil compared to the level reported in the literature, this is critical for the measurement of plutonium isotopes using mass spectrometric technique. Although the chemical yield of Pu in the entire procedure is about 55%, the analytical results of IAEA soil 6 and IAEA-367 in this work are in a good agreement with the values reported in the literature or reference values, revealing that the developed method for plutonium determination in environmental samples is reliable. The measurement results of (239+240)Pu by alpha spectrometry agreed very well with the sum of (239)Pu and (240)Pu measured by ICP-MS. ICP-MS can not only measure (239)Pu and (240)Pu separately but also (241)Pu. However, it is impossible to measure (238)Pu using ICP-MS in environmental samples even a decontamination factor as high as 10(6) for uranium was obtained by chemical separation. © 2013 Elsevier B.V. All rights reserved.

  10. Automation of radiometric testing

    Chekalin, A.S.; Temnik, A.K.; Butakova, G.E.; Goncharov, V.I.

    1983-01-01

    The main prerequisites for creation of automatic systems of radiometric testing as the means to increase the testing objectivity and quality have been considered, principles of their design being developed. The operating system is described for testing complex configuration products using RD-10R gamma flow detector as a sensor of initial information

  11. Aerosol-Fluorescence Spectrum Analyzer: Real-Time Measurement of Emission Spectra of Airborne Biological Particles

    Hill, Steven

    1997-01-01

    ...) made from various biological materials (e.g., Bacillus subtilis spores, B. anthrasis spores, riboflavin, and tree leaves). The AFS may be useful in detecting and characterizing airborne bacteria and other airborne particles of biological origin.

  12. Measurements of ocean wave spectra and modulation transfer function with the airborne two-frequency scatterometer

    Weissman, D. E.; Johnson, J. W.

    1986-01-01

    The directional spectrum and the microwave modulation transfer function of ocean waves can be measured with the airborne two frequency scatterometer technique. Similar to tower based observations, the aircraft measurements of the Modulation Transfer Function (MTF) show that it is strongly affected by both wind speed and sea state. Also detected are small differences in the magnitudes of the MTF between downwind and upwind radar look directions, and variations with ocean wavenumber. The MTF inferred from the two frequency radar is larger than that measured using single frequency, wave orbital velocity techniques such as tower based radars or ROWS measurements from low altitude aircraft. Possible reasons for this are discussed. The ability to measure the ocean directional spectrum with the two frequency scatterometer, with supporting MTF data, is demonstrated.

  13. Measurements of ocean wave spectra and modulation transfer function with the airborne two frequency scatterometer

    Weissman, D. E.; Johnson, J. W.

    1984-01-01

    The directional spectrum and the microwave modulation transfer function of ocean waves can be measured with the airborne two frequency scatterometer technique. Similar to tower based observations, the aircraft measurements of the Modulation Transfer Function (MTF) show that it is strongly affected by both wind speed and sea state. Also detected are small differences in the magnitudes of the MTF between downwind and upwind radar look directions, and variations with ocean wavenumber. The MTF inferred from the two frequency radar is larger than that measured using single frequency, wave orbital velocity techniques such as tower based radars or ROWS measurements from low altitude aircraft. Possible reasons for this are discussed. The ability to measure the ocean directional spectrum with the two frequency scatterometer, with supporting MTF data, is demonstrated.

  14. Tasmanian tin and tungsten granites - their radiometric characteristics

    Yeates, A.N.

    1982-01-01

    A radiometric survey of Tasmanian granites has shown, with one exception, that tin and tungsten-bearing granites have high radioactivity, largely owing to increased uranium. Many have a high uranium/thorium ratio as well. Radiometric measurements can also delineate different granite types within composite bodies

  15. The correlation and quantification of airborne spectroradiometer data to turbidity measurements at Lake Powell, Utah

    Merry, C. J.

    1979-01-01

    A water sampling program was accomplished at Lake Powell, Utah, during June 1975 for correlation to multispectral data obtained with a 500-channel airborne spectroradiometer. Field measurements were taken of percentage of light transmittance, surface temperature, pH and Secchi disk depth. Percentage of light transmittance was also measured in the laboratory for the water samples. Analyses of electron micrographs and suspended sediment concentration data for four water samples located at Hite Bridge, Mile 168, Mile 150 and Bullfrog Bay indicated differences in the composition and concentration of the particulate matter. Airborne spectroradiometer multispectral data were analyzed for the four sampling locations. The results showed that: (1) as the percentage of light transmittance of the water samples decreased, the reflected radiance increased; and (2) as the suspended sediment concentration (mg/l) increased, the reflected radiance increased in the 1-80 mg/l range. In conclusion, valuable qualitative information was obtained on surface turbidity for the Lake Powell water spectra. Also, the reflected radiance measured at a wavelength of 0.58 micron was directly correlated to the suspended sediment concentration.

  16. Airborne remote sensing and in situ measurements of atmospheric CO2 to quantify point source emissions

    Krings, Thomas; Neininger, Bruno; Gerilowski, Konstantin; Krautwurst, Sven; Buchwitz, Michael; Burrows, John P.; Lindemann, Carsten; Ruhtz, Thomas; Schüttemeyer, Dirk; Bovensmann, Heinrich

    2018-02-01

    Reliable techniques to infer greenhouse gas emission rates from localised sources require accurate measurement and inversion approaches. In this study airborne remote sensing observations of CO2 by the MAMAP instrument and airborne in situ measurements are used to infer emission estimates of carbon dioxide released from a cluster of coal-fired power plants. The study area is complex due to sources being located in close proximity and overlapping associated carbon dioxide plumes. For the analysis of in situ data, a mass balance approach is described and applied, whereas for the remote sensing observations an inverse Gaussian plume model is used in addition to a mass balance technique. A comparison between methods shows that results for all methods agree within 10 % or better with uncertainties of 10 to 30 % for cases in which in situ measurements were made for the complete vertical plume extent. The computed emissions for individual power plants are in agreement with results derived from emission factors and energy production data for the time of the overflight.

  17. High resolution simultaneous measurements of airborne radionuclides in the pan-Japan sea area

    Yamaguchi, Y.; Abe, T.; Murata, Y.M.; Manikandan, N.; Tanaka, K.; Komura, K.

    2006-01-01

    By the use of ultra low background Ge detectors at Ogoya Underground Laboratory (OUL), it became possible to detect extremely low levels of environmental radionuclides. In this study, we tried to measure high resolution simultaneous measurements of airborne radionuclides at three monitoring points, i.e., 1) Low Level Radioactivity Laboratory (LLRL 40m asl) in Nomi City as the regular monitoring point, 2) Hegura Island Located 50 km from Noto Peninsula in the Sea of Japan to investigate the influence of Asian continent or mainland of Japan, and 3) Shishiku Plateau (640m asl) located about 8 km from LLRL to know vertical difference. Pb-210 and Be-7 were measured nondestructively by ultra low background gamma spectrometry at OUL, Po-210 by alpha spectrometry using Si detectors after the chemical treatment. Various interesting results on the concentrations and variation patterns of airborne radionuclides were obtained, particularly, during drastic meteorological changes such as the passage of typhoon, snow fall and so on. We have been analyzing the influence of the arrival of yellow sand occurred in this spring. (author)

  18. 3D Numerical study of the external flow effect on the heat transfer in a radiometric calorimeter dedicated to nuclear heating measurements

    Muraglia, M.; Reynard-Carette, C.; Brun, J.; Carette, M.; Lyoussi, A.

    2013-06-01

    Improvement of measurements in reactor is still a challenge. Thus, this work focuses on numerical studies of one sensor dedicated to nuclear heating measurements: a radiometric complex calorimeter. More precisely, using a simplified conduction heat model, this work presents the first full 3D simulations of a simplified calorimeter reduced to the complex calorimeter head showing that the key parameter for the sensitivity control is the convective heat transfers between the calorimeter and its external surrounding. The effect of external flow velocity on the calorimeter head response is determined for different flow regimes (natural convection, forced convection) and numerical results are found to be in agreement with experimental results under non-irradiated conditions obtained for the complex calorimeter. Moreover, in order to understand and describe fully the mechanisms leading at the different calorimeter heat transfer, the flow velocity dynamics should be added in the model. In a first approach, due to low influence of the flow velocity for tested power range, a static cooling fluid around the calorimeter head is added in the model. Then, in order to get the full flow dynamics, using Boussinesq approximation, a new 2D fluid model, including both temperature field and flow velocity dynamics, is derived taking into account the nuclear heating effect on the flow. (authors)

  19. Airborne mapping of Seoul's atmosphere: Trace gas measurements from GeoTASO during KORUS-AQ

    Nowlan, C. R.; Al-Saadi, J. A.; Castellanos, P.; Chance, K.; Gonzalez Abad, G.; Janz, S. J.; Judd, L.; Kowalewski, M. G.; Liu, X.

    2017-12-01

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) instrument is a pushbroom airborne remote sensing instrument capable of making measurements of air quality and ocean color using backscattered UV and visible light. GeoTASO is an airborne test-bed for the upcoming Tropospheric Emissions: Monitoring of Pollution (TEMPO) and Geostationary Environment Monitoring Spectrometer (GEMS) geostationary satellite missions, which will measure air quality over North America and Asia, respectively. GeoTASO also acts as a satellite analogue during field campaigns. GeoTASO flew on the NASA Langley Research Center UC-12 aircraft during the Korea-United States Air Quality Study in May-June 2016, collecting spectra over South Korea during 30 flights over 19 flight days. These observations can be used to derive 2-D maps of tropospheric trace gases including ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, nitrous acid and glyoxal below the aircraft at spatial resolutions between 250 m x 250 m and 1 km x 1 km, depending on the gas. We present spatially resolved trace gas retrievals over Seoul and its surrounding industrial regions, and comparisons with correlative satellite and campaign data.

  20. Ultrafine particles from power plants: Evaluation of WRF-Chem simulations with airborne measurements

    Forkel, Renate; Junkermann, Wolfgang

    2017-04-01

    Ultrafine particles (UFP, particles with a diameter risk to human health and have a potential effect on climate as their presence affects the number concentration of cloud condensation nuclei. Despite of the possibly hazardous effects no regulations exist for this size class of ambient air pollution particles. While ground based continuous measurements of UFP are performed in Germany at several sites (e.g. the German Ultrafine Aerosol Network GUAN, Birmili et al. 2016, doi:10.5194/essd-8-355-2016) information about the vertical distribution of UFP within the atmospheric boundary layer is only scarce. This gap has been closed during the last years by regional-scale airborne surveys for UFP concentrations and size distributions over Germany (Junkermann et al., 2016, doi: 10.3402/tellusb.v68.29250) and Australia (Junkermann and Hacker, 2015, doi: 10.3402/tellusb.v67.25308). Power stations and refineries have been identified as a major source of UFP in Germany with observed particle concentrations > 50000 particles cm-3 downwind of these elevated point sources. Nested WRF-Chem simulations with 2 km grid width for the innermost domain are performed with UFP emission source strengths derived from the measurements in order to study the advection and vertical exchange of UFP from power plants near the Czech and Polish border and their impact on planetary boundary layer particle patterns. The simulations are evaluated against the airborne observations and the downward mixing of the UFP from the elevated sources is studied.

  1. Airborne High Spectral Resolution Lidar Aerosol Measurements during MILAGRO and TEXAQS/GOMACCS

    Ferrare, Richard; Hostetler, Chris; Hair, John; Cook Anthony; Harper, David; Burton, Sharon; Clayton, Marian; Clarke, Antony; Russell, Phil; Redemann, Jens

    2007-01-01

    Two1 field experiments conducted during 2006 provided opportunities to investigate the variability of aerosol properties near cities and the impacts of these aerosols on air quality and radiative transfer. The Megacity Initiative: Local and Global Research Observations (MILAGRO) /Megacity Aerosol Experiment in Mexico City (MAX-MEX)/Intercontinental Chemical Transport Experiment-B (INTEX-B) joint experiment conducted during March 2006 investigated the evolution and transport of pollution from Mexico City. The Texas Air Quality Study (TEXAQS)/Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) (http://www.al.noaa.gov/2006/) conducted during August and September 2006 investigated climate and air quality in the Houston/Gulf of Mexico region. During both missions, the new NASA Langley airborne High Spectral Resolution Lidar (HSRL) was deployed on the NASA Langley B200 King Air aircraft and measured profiles of aerosol extinction, backscattering, and depolarization to: 1) characterize the spatial and vertical distributions of aerosols, 2) quantify aerosol extinction and optical thickness contributed by various aerosol types, 3) investigate aerosol variability near clouds, 4) evaluate model simulations of aerosol transport, and 5) assess aerosol optical properties derived from a combination of surface, airborne, and satellite measurements.

  2. The Periodic Measurement of the Airborne Radioactivity In Controlled Area of KOMAC

    Park, Jeong-Min; Park, Sung-Kyun; Min, Yi-Sub; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Korea Multipurpose Accelerator Complex (KOMAC) to start the performance operation in the second half of 2013, is currently operated in each beamline 20-MeV and 100-MeV. The accelerator operation period is simply divided by three operation cycles which are the maintenance checks period for accelerator device, the performance test period before driving accelerator and the operation period. During this operation period, beam is irradiated to target. At this time, the proton beams collide with the target material and a high dose of radiations such as gamma ray and neutron occurred. Radiation controlled area at the accelerator facility is divided into accelerator tunnel and beam utilization zone. As a result of measuring the airborne radioactivity in the controlled area in accordance with the operating cycle of the proton accelerator KOMAC, It was confirmed that the value of the airborne radioactivity does not significantly differ according to each accelerator operating cycles. And alpha and beta values measured inside the area that workers primarily work is very low indoor radon level than the value of the recommendations in multiple facilities.

  3. Airborne Lidar for Simultaneous Measurement of Column CO2 and Water Vapor in the Atmosphere

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Antill, Charles W.; Remus, Ruben; Yu, Jirong

    2016-01-01

    The 2-micron wavelength region is suitable for atmospheric carbon dioxide (CO2) measurements due to the existence of distinct absorption feathers for the gas at this particular wavelength. For more than 20 years, researchers at NASA Langley Research Center (LaRC) have developed several high-energy and high repetition rate 2-micron pulsed lasers. This paper will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar. The development of this active optical remote sensing IPDA instrument is targeted for measuring both CO2 and water vapor (H2O) in the atmosphere from an airborne platform. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver telescope, detection system and data acquisition. Future plans for the IPDA lidar system for ground integration, testing and flight validation will also be presented.

  4. Panay carborne radiometric and geochemical surveys

    Santos, G. Jr.

    1981-09-01

    A carborne radiometric survey and stream sediments collection were conducted in Panay and Guimaras Islands. An area in Nabas, Aklan, situated in the northwestern tip of Panay (Buruanga Peninsula) which indicated 2 to 3 times above background radioactivity was delineated. Uranium content in the stream sediment samples collected from Buruanga Peninsula was generally higher than those obtained in other parts of the island. Radioactivity measurements and uranium content in stream sediments were found to be within background levels. It is recommended that follow-up radiometric and geochemical surveys be undertaken in Buruanga Peninsula and additional stream sediments samples be collected in Panay to achieve better sampling density and coverage. (author)

  5. Atmospheric CO2 Concentration Measurements with Clouds from an Airborne Lidar

    Mao, J.; Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Hasselbrack, W. E.; Numata, K.; Chen, J. R.; Sun, X.; DiGangi, J. P.; Choi, Y.

    2017-12-01

    Globally distributed atmospheric CO2 concentration measurements with high precision, low bias and full seasonal sampling are crucial to advance carbon cycle sciences. However, two thirds of the Earth's surface is typically covered by clouds, and passive remote sensing approaches from space are limited to cloud-free scenes. NASA Goddard is developing a pulsed, integrated-path differential absorption (IPDA) lidar approach to measure atmospheric column CO2 concentrations, XCO2, from space as a candidate for NASA's ASCENDS mission. Measurements of time-resolved laser backscatter profiles from the atmosphere also allow this technique to estimate XCO2 and range to cloud tops in addition to those to the ground with precise knowledge of the photon path-length. We demonstrate this measurement capability using airborne lidar measurements from summer 2017 ASCENDS airborne science campaign in Alaska. We show retrievals of XCO2 to ground and to a variety of cloud tops. We will also demonstrate how the partial column XCO2 to cloud tops and cloud slicing approach help resolving vertical and horizontal gradient of CO2 in cloudy conditions. The XCO2 retrievals from the lidar are validated against in situ measurements and compared to the Goddard Parameterized Chemistry Transport Model (PCTM) simulations. Adding this measurement capability to the future lidar mission for XCO2 will provide full global and seasonal data coverage and some information about vertical structure of CO2. This unique facility is expected to benefit atmospheric transport process studies, carbon data assimilation in models, and global and regional carbon flux estimation.

  6. Airborne Lidar Measurements of Atmospheric Pressure Made Using the Oxygen A-Band

    Riris, Haris; Rodriquez, Michael D.; Allan, Graham R.; Hasselbrack, William E.; Mao, Jianping; Stephen, Mark A.; Abshire, James B.

    2012-01-01

    Accurate measurements of greenhouse gas mixing ratios on a global scale are currently needed to gain a better understanding of climate change and its possible impact on our planet. In order to remotely measure greenhouse gas concentrations in the atmosphere with regard to dry air, the air number density in the atmosphere is also needed in deriving the greenhouse gas concentrations. Since oxygen is stable and uniformly mixed in the atmosphere at 20.95%, the measurement of an oxygen absorption in the atmosphere can be used to infer the dry air density and used to calculate the dry air mixing ratio of a greenhouse gas, such as carbon dioxide or methane. OUT technique of measuring Oxygen uses integrated path differential absorption (IPDA) with an Erbium Doped Fiber Amplifier (EDF A) laser system and single photon counting module (SPCM). It measures the absorbance of several on- and off-line wavelengths tuned to an O2 absorption line in the A-band at 764.7 nm. The choice of wavelengths allows us to maximize the pressure sensitivity using the trough between two absorptions in the Oxygen A-band. Our retrieval algorithm uses ancillary meteorological and aircraft altitude information to fit the experimentally obtained lidar O2 line shapes to a model atmosphere and derives the pressure from the profiles of the two lines. We have demonstrated O2 measurements from the ground and from an airborne platform. In this paper we will report on our airborne measurements during our 2011 campaign for the ASCENDS program.

  7. Radiometric maps of Israel - Partial contribution to the understanding of potential radon emanations

    Vulkan, U.; Shirav, M.

    1997-01-01

    An airborne radiometric survey over parts of Israel was carried out in 1981. The system was comprised from 10 Nal 4 inch x 4 inch x 16 inch detectors, arranged in 4,4 and 2 sensors, with total volume of 1560 inch 3 , and one 4 inch x 4 inch x 16 inch uplooking Nal detector. Flight nominal height was 400 feet. It was found that the Mount Scopus Group (of Senonian origin) is the main source for high uranium - phosphorite rocks of this group contain up to 150 ppm U. Comparing the eU radiometric map with a map of potential radon emanation from rock units, reveals a fair correlation - high radon emanation usually follow the distribution of the Mount Scopus Group in Israel. The correlation between the two maps is excellent over arid terrain where soil cover is missing, whereas over semi-arid - humid areas (western and northern Israel), where soil and cultivation covers are developed, the eU levels over Mount Scopus Group's outcrops are much lower due to absorption of the radiation, and do not depict the full radon potential. Detailed mapping of radon hazards usually exhibit poor correlation between airborne eU data and direct pore radon measurements, even in arid terrain. This phenomenon is attributed to the fact that a radon ''source rock'' (e.g. phosphorite) could be covered with a few up to some tenths of meters of uranium-barren rock. About 0.5 meter cover is enough to absorb all radiation, causing very low airborne eU readings, while the radon free way in this rock is about 10 meters, yielding high pore radon levels when directly measured

  8. RADIOMETRIC BLOCK ADJUSMENT AND DIGITAL RADIOMETRIC MODEL GENERATION

    A. Pros

    2013-05-01

    Full Text Available In this paper we present a radiometric block adjustment method that is related to geometric block adjustment and to the concept of a terrain Digital Radiometric Model (DRM as a complement to the terrain digital elevation and surface models. A DRM, in our concept, is a function that for each ground point returns a reflectance value and a Bidirectional Reflectance Distribution Function (BRDF. In a similar way to the terrain geometric reconstruction procedure, given an image block of some terrain area, we split the DRM generation in two phases: radiometric block adjustment and DRM generation. In the paper we concentrate on the radiometric block adjustment step, but we also describe a preliminary DRM generator. In the block adjustment step, after a radiometric pre-calibraton step, local atmosphere radiative transfer parameters, and ground reflectances and BRDFs at the radiometric tie points are estimated. This radiometric block adjustment is based on atmospheric radiative transfer (ART models, pre-selected BRDF models and radiometric ground control points. The proposed concept is implemented and applied in an experimental campaign, and the obtained results are presented. The DRM and orthophoto mosaics are generated showing no radiometric differences at the seam lines.

  9. Studies of environmental radioactivity in Cumbria: Part 3. Measurements of radionuclides in airborne and deposited material

    Pattenden, N.J.; Cambray, R.S.; Playford, K.; Eakins, J.D.; Fisher, E.M.R.

    1980-09-01

    Six stations sampling airborne particulate and deposited material were established in the Cumbrian coastal region. The measurements were undertaken to study current atmospheric levels and to discriminate between material from nuclear weapon tests, routine atmospheric discharges from the nuclear reprocessing works at Windscale and other sources, e.g. the sea. The results show that samples of both airborne and deposited material contain radionuclide concentrations in excess of those expected from nuclear weapon fallout. For Pu and 241 Am isotopes, the excess material comes mainly from a seaward direction. The transfer mechanism is probably resuspension, but the actinide levels are much greater than would be expected from the simple transfer of bulk seawater. For 137 Cs, the material in excess of amounts expected from nuclear weapon fallout can be attributed largely to Windscale discharges to air and seaspray containing the bulk seawater concentration of 137 Cs. Other fission products present in amounts exceeding nuclear weapon fallout were 106 Ru, 125 Sb, 134 Cs and 144 Ce. Tritium was also observed in amounts slightly in excess of nuclear weapon fallout. The highest observed annual average concentration in air for Pu isotopes was 0.2% of the derived air concentration, modified for members of the public, of 2.3 mBq/m 3 . (author)

  10. Measurements of land surface features using an airborne laser altimeter: the HAPEX-Sahel experiment

    Ritchie, J.C.; Menenti, M.; Weltz, M.A.

    1997-01-01

    An airborne laser profiling altimeter was used to measure surface features and properties of the landscape during the HAPEX-Sahel Experiment in Niger, Africa in September 1992. The laser altimeter makes 4000 measurements per second with a vertical resolution of 5 cm. Airborne laser and detailed field measurements of vegetation heights had similar average heights and frequency distribution. Laser transects were used to estimate land surface topography, gully and channel morphology, and vegetation properties ( height, cover and distribution). Land surface changes related to soil erosion and channel development were measured. For 1 km laser transects over tiger bush communities, the maximum vegetation height was between 4-5 and 6-5 m, with an average height of 21 m. Distances between the centre of rows of tiger bush vegetation averaged 100 m. For two laser transects, ground cover for tiger bush was estimated to be 225 and 301 per cent for vegetation greater than 0-5m tall and 190 and 25-8 per cent for vegetation greater than 10m tall. These values are similar to published values for tiger bush. Vegetation cover for 14 and 18 km transects was estimated to be 4 per cent for vegetation greater than 0-5 m tall. These cover values agree within 1-2 per cent with published data for short transects (⩾ 100 m) for the area. The laser altimeter provided quick and accurate measurements for evaluating changes in land surface features. Such information provides a basis for understanding land degradation and a basis for management plans to rehabilitate the landscape. (author)

  11. The profile of the electron beam in the PTB synchrotron, and its influence on radiometric measurements with synchrotron radiation

    Kaase, H.

    1976-01-01

    A simple method is described to determine the beam profile in an electron synchrotron; the measured results are compared with calculated values. Moreover, the influence of synchrotron- and betatron-oscillations on synchrotron radiation measurements is discussed, and a method is given to correct this. (orig.) [de

  12. Airborne asbestos fibre levels in buildings: a summary of UK measurements.

    Burdett, G J; Jaffrey, S A; Rood, A P

    1989-01-01

    The UK Health and Safety Executive, in conjunction with the Department of the Environment, has carried out a number of surveys of airborne asbestos fibre concentrations in buildings. All samples have been collected on membrane filters and analysed by analytical transmission electron microscopy. Four categories of buildings under normal occupation have been investigated; non-domestic buildings containing sprayed or trowelled asbestos, domestic buildings containing sprayed asbestos or asbestos plaster, buildings with warm air heaters containing asbestos and buildings without asbestos materials. A number of buildings have also been surveyed during and after the removal of asbestos materials. The choice of measurement indices and analytical procedures is reviewed, before measurements are compared in terms of the concentration of asbestos fibres greater than 5 microns long. The decision whether to remove asbestos from occupied buildings is discussed with reference to the associated cost and risk. In the present survey, management of undamaged asbestos appeared preferable to large-scale removal.

  13. Radiometric diagnosis of Mycobacterium tuberculosis

    Laszlo, A.

    1986-01-01

    The results of this study confirm that rapid radiometric diagnostic tests such as the NAP selective inhibition test for the M. tuberculosis complex followed by the radiometric drug susceptibility tests are extremely reliable and compare favourably with conventional methodologies. This study also shows that referred cultures growing on solid medium can be processed by radiometric procedures without prior subculture. This circumstance by itself shortens the time needed for reporting. (Auth.)

  14. Airborne measurements of isoprene and monoterpene emissions from southeastern U.S. forests

    Yu, Haofei; Guenther, Alex; Gu, Dasa; Warneke, Carsten; Geron, Chris; Goldstein, Allen; Graus, Martin; Karl, Thomas; Kaser, Lisa; Misztal, Pawel; Yuan, Bin

    2017-10-01

    Isoprene and monoterpene emission rates are essential inputs for atmospheric chemistry models that simulate atmospheric oxidant and particle distributions. Process studies of the biochemical and physiological mechanisms controlling these emissions are advancing our understanding and the accuracy of model predictions but efforts to quantify regional emissions have been limited by a lack of constraints on regional distributions of ecosystem emission capacities. We used an airborne wavelet-based eddy covariance measurement technique to characterize isoprene and monoterpene fluxes with high spatial resolution during the 2013 SAS (Southeast Atmosphere Study) in the southeastern United States. The fluxes measured by direct eddy covariance were comparable to emissions independently estimated using an indirect inverse modeling approach. Isoprene emission factors based on the aircraft wavelet flux estimates for high isoprene chemotypes (e.g., oaks) were similar to the MEGAN2.1 biogenic emission model estimates for landscapes dominated by oaks. Aircraft flux measurement estimates for landscapes with fewer isoprene emitting trees (e.g., pine plantations), were about a factor of two lower than MEGAN2.1 model estimates. The tendency for high isoprene emitters in these landscapes to occur in the shaded understory, where light dependent isoprene emissions are diminished, may explain the lower than expected emissions. This result demonstrates the importance of accurately representing the vertical profile of isoprene emitting biomass in biogenic emission models. Airborne measurement-based emission factors for high monoterpene chemotypes agreed with MEGAN2.1 in landscapes dominated by pine (high monoterpene chemotype) trees but were more than a factor of three higher than model estimates for landscapes dominated by oak (relatively low monoterpene emitting) trees. This results suggests that unaccounted processes, such as floral emissions or light dependent monoterpene emissions, or

  15. Airborne measurements of isoprene and monoterpene emissions from southeastern U.S. forests.

    Yu, Haofei; Guenther, Alex; Gu, Dasa; Warneke, Carsten; Geron, Chris; Goldstein, Allen; Graus, Martin; Karl, Thomas; Kaser, Lisa; Misztal, Pawel; Yuan, Bin

    2017-10-01

    Isoprene and monoterpene emission rates are essential inputs for atmospheric chemistry models that simulate atmospheric oxidant and particle distributions. Process studies of the biochemical and physiological mechanisms controlling these emissions are advancing our understanding and the accuracy of model predictions but efforts to quantify regional emissions have been limited by a lack of constraints on regional distributions of ecosystem emission capacities. We used an airborne wavelet-based eddy covariance measurement technique to characterize isoprene and monoterpene fluxes with high spatial resolution during the 2013 SAS (Southeast Atmosphere Study) in the southeastern United States. The fluxes measured by direct eddy covariance were comparable to emissions independently estimated using an indirect inverse modeling approach. Isoprene emission factors based on the aircraft wavelet flux estimates for high isoprene chemotypes (e.g., oaks) were similar to the MEGAN2.1 biogenic emission model estimates for landscapes dominated by oaks. Aircraft flux measurement estimates for landscapes with fewer isoprene emitting trees (e.g., pine plantations), were about a factor of two lower than MEGAN2.1 model estimates. The tendency for high isoprene emitters in these landscapes to occur in the shaded understory, where light dependent isoprene emissions are diminished, may explain the lower than expected emissions. This result demonstrates the importance of accurately representing the vertical profile of isoprene emitting biomass in biogenic emission models. Airborne measurement-based emission factors for high monoterpene chemotypes agreed with MEGAN2.1 in landscapes dominated by pine (high monoterpene chemotype) trees but were more than a factor of three higher than model estimates for landscapes dominated by oak (relatively low monoterpene emitting) trees. This results suggests that unaccounted processes, such as floral emissions or light dependent monoterpene emissions, or

  16. Development of an Internally-Calibrated Wide-Band Airborne Microwave Radiometer to Provide High-Resolution Wet-Tropospheric Path Delay Measurements for SWOT (HAMMR - High-frequency Airborne Microwave and Millimeter-wave Radiometer)

    National Aeronautics and Space Administration — Development of an Internally-Calibrated Wide-Band Airborne Microwave Radiometer to Provide High-Resolution Wet-Tropospheric Path Delay Measurements for SWOT (HAMMR -...

  17. A Decade of High-Resolution Arctic Sea Ice Measurements from Airborne Altimetry

    Duncan, K.; Farrell, S. L.; Connor, L. N.; Jackson, C.; Richter-Menge, J.

    2017-12-01

    Satellite altimeters carried on board ERS-1,-2, EnviSat, ICESat, CryoSat-2, AltiKa and Sentinel-3 have transformed our ability to map the thickness and volume of the polar sea ice cover, on seasonal and decadal time-scales. The era of polar satellite altimetry has coincided with a rapid decline of the Arctic ice cover, which has thinned, and transitioned from a predominantly multi-year to first-year ice cover. In conjunction with basin-scale satellite altimeter observations, airborne surveys of the Arctic Ocean at the end of winter are now routine. These surveys have been targeted to monitor regions of rapid change, and are designed to obtain the full snow and ice thickness distribution, across a range of ice types. Sensors routinely deployed as part of NASA's Operation IceBridge (OIB) campaigns include the Airborne Topographic Mapper (ATM) laser altimeter, the frequency-modulated continuous-wave snow radar, and the Digital Mapping System (DMS). Airborne measurements yield high-resolution data products and thus present a unique opportunity to assess the quality and characteristics of the satellite observations. We present a suite of sea ice data products that describe the snow depth and thickness of the Arctic ice cover during the last decade. Fields were derived from OIB measurements collected between 2009-2017, and from reprocessed data collected during ad-hoc sea ice campaigns prior to OIB. Our bespoke algorithms are designed to accommodate the heterogeneous sea ice surface topography, that varies at short spatial scales. We assess regional and inter-annual variability in the sea ice thickness distribution. Results are compared to satellite-derived ice thickness fields to highlight the sensitivities of satellite footprints to the tails of the thickness distribution. We also show changes in the dynamic forcing shaping the ice pack over the last eight years through an analysis of pressure-ridge sail-height distributions and surface roughness conditions

  18. Analysis of γ spectra in airborne radioactivity measurements using multiple linear regressions

    Bao Min; Shi Quanlin; Zhang Jiamei

    2004-01-01

    This paper describes the net peak counts calculating of nuclide 137 Cs at 662 keV of γ spectra in airborne radioactivity measurements using multiple linear regressions. Mathematic model is founded by analyzing every factor that has contribution to Cs peak counts in spectra, and multiple linear regression function is established. Calculating process adopts stepwise regression, and the indistinctive factors are eliminated by F check. The regression results and its uncertainty are calculated using Least Square Estimation, then the Cs peak net counts and its uncertainty can be gotten. The analysis results for experimental spectrum are displayed. The influence of energy shift and energy resolution on the analyzing result is discussed. In comparison with the stripping spectra method, multiple linear regression method needn't stripping radios, and the calculating result has relation with the counts in Cs peak only, and the calculating uncertainty is reduced. (authors)

  19. Characterizing the solar reflection from wildfire smoke plumes using airborne multiangle measurements

    Gatebe, C. K.; Varnai, T.; Gautam, R.; Poudyal, R.; Singh, M. K.

    2016-12-01

    To help better understand forest fire smoke plumes, this study examines sunlight reflected from plumes that were observed over Canada during the ARCTAS campaign in summer 2008. In particular, the study analyzes multiangle and multispectral measurements of smoke scattering by the airborne Cloud Absorption Radiometer (CAR). In combination with other in-situ and remote sensing information and radiation modeling, CAR data is used for characterizing the radiative properties and radiative impact of smoke particles—which inherently depend on smoke particle properties that influence air quality. In addition to estimating the amount of reflected and absorbed sunlight, the work includes using CAR data to create spectral and broadband top-of-atmosphere angular distribution models (ADMs) of solar radiation reflected by smoke plumes, and examining the sensitivity of such angular models to scene parameters. Overall, the results help better understand the radiative properties and radiative effects of smoke particles, and are anticipated to help better interpret satellite data on smoke plumes.

  20. An alternative method for the estimation of sedimentation rates using radiometric measurements in an intertidal region (sw of spain)

    Ligero, Rufino; Casas-Ruiz, Melquiades; Barrera, Manuel; Barbero, Luis

    2010-05-01

    The techniques for the direct measurement of the sedimentation rate are reliable but slow and imprecise, given that the time intervals of measurement cannot be very long. Consequently it is an extremely laborious task to obtain a representative map of the sedimentation rates and such maps are available for very few zones. However, for most environmental studies, it is very important to know the sedimentation rates. The high degree of accuracy of the gamma spectrometric techniques together with the application of the model describes in this work, has allowed the determination of the sedimentation rates in a wide spatial area such of the Bay of Cadiz to be obtained with precision and consuming considerably less time in comparison to the traditional techniques. Even so, the experimental conditions required for the sample cores are fairly restrictive, and although the radiological method provides a quantitative advance in measurement, the experimental difficulty in the execution of the study is not greatly diminished. For this reason, a second model has been derived based on the measurement of the inventory, which offers economies in time and financial cost, and which allows the sedimentation rate in a region to be determined with satisfactory accuracy. Furthermore, it has been shown that the application of this model requires a precise determination of 137Cs inventories. The sedimentation rates estimated by the 137Cs inventory method ranged from 0.26 cm/year to 1.72 cm/year. The average value of the sedimentation rate obtained is 0.59 cm/year, and this rate has been compared with those resulting from the application of the 210Pb dating technique. A good agreement between the two procedures has been found. From the study carried out, it has been possible for the first time, to draw a map of sedimentation rates for this zone where numerous physical-chemical, oceanographic and ecological studies converge, since it is situated in a region of great environmental interest

  1. Radiometric measurements of wall temperatures in the 800 K to 1150 K range for a quartz radiant heating tube

    Blevins, L.G.; Sivathanu, Y.R.; Gore, J.P.; Shahien, M.A.

    1995-01-01

    Many industrial applications require heat transfer to a load in an inert environment, which can be achieved by using gas-fired radiant tubes. A radiant tube consists of a flame confined in a cylindrical metal or ceramic chamber. The flame heats the tube wall, which in turn radiates to the load. One important characteristic of radiant heating tubes is wall temperature uniformity. Numerical models of radiant tubes have been used to predict wall temperatures, but there is a lack of experimental data for validation. Recently, Namazian et al., Singh and Gorski, and Peters et al. have measured wall temperature profiles of radiant tubes using thermocouples. 13 refs., 3 figs

  2. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols

    Carter, Arlen F.; Allen, Robert J.; Mayo, M. Neale; Butler, Carolyn F.; Grossman, Benoist E.; Ismail, Syed; Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Mayor, Shane D.; hide

    1994-01-01

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H2O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and greater than 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H2O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H2O absorption-line parameters were performed to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H2O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H2O radiosondes. The H2O distributions measured with the DIAL system differed by less than 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  3. NIS method for uncertainty estimation of airborne sound insulation measurement in field

    El-Basheer Tarek M.

    2017-01-01

    Full Text Available In structures, airborne sound insulation is utilized to characterize the acoustic nature of barriers between rooms. However, the assessment of sound insulation index is once in a while troublesome or indeed, even questionable, both in field and laboratory measurements, notwithstanding the way that there are some unified measurement methodology indicated in the ISO 140 series standards. There are issues with the reproducibility and repeatability of the measurement results. A few troubles might be brought on by non-diffuse acoustic fields, non-uniform reverberation time, or blunders of the reverberation time measurements. Some minor issues are additionally postured by flanking transmission. In this paper, investigation of the uncertainties of the above specified measurement parts and their impact on the consolidated uncertainty in 1/3-octave frequency band. The total measurement uncertainty model contributes several different partial uncertainties, which are evaluated by the method of type A or type B. Also, the determination of the sound reduction index decided by ISO 140-4 has been performed.

  4. Evaluating signal-to-noise ratios, loudness, and related measures as indicators of airborne sound insulation.

    Park, H K; Bradley, J S

    2009-09-01

    Subjective ratings of the audibility, annoyance, and loudness of music and speech sounds transmitted through 20 different simulated walls were used to identify better single number ratings of airborne sound insulation. The first part of this research considered standard measures such as the sound transmission class the weighted sound reduction index (R(w)) and variations of these measures [H. K. Park and J. S. Bradley, J. Acoust. Soc. Am. 126, 208-219 (2009)]. This paper considers a number of other measures including signal-to-noise ratios related to the intelligibility of speech and measures related to the loudness of sounds. An exploration of the importance of the included frequencies showed that the optimum ranges of included frequencies were different for speech and music sounds. Measures related to speech intelligibility were useful indicators of responses to speech sounds but were not as successful for music sounds. A-weighted level differences, signal-to-noise ratios and an A-weighted sound transmission loss measure were good predictors of responses when the included frequencies were optimized for each type of sound. The addition of new spectrum adaptation terms to R(w) values were found to be the most practical approach for achieving more accurate predictions of subjective ratings of transmitted speech and music sounds.

  5. Evaluating standard airborne sound insulation measures in terms of annoyance, loudness, and audibility ratings.

    Park, H K; Bradley, J S

    2009-07-01

    This paper reports the results of an evaluation of the merits of standard airborne sound insulation measures with respect to subjective ratings of the annoyance and loudness of transmitted sounds. Subjects listened to speech and music sounds modified to represent transmission through 20 different walls with sound transmission class (STC) ratings from 34 to 58. A number of variations in the standard measures were also considered. These included variations in the 8-dB rule for the maximum allowed deficiency in the STC measure as well as variations in the standard 32-dB total allowed deficiency. Several spectrum adaptation terms were considered in combination with weighted sound reduction index (R(w)) values as well as modifications to the range of included frequencies in the standard rating contour. A STC measure without an 8-dB rule and an R(w) rating with a new spectrum adaptation term were better predictors of annoyance and loudness ratings of speech sounds. R(w) ratings with one of two modified C(tr) spectrum adaptation terms were better predictors of annoyance and loudness ratings of transmitted music sounds. Although some measures were much better predictors of responses to one type of sound than were the standard STC and R(w) values, no measure was remarkably improved for predicting annoyance and loudness ratings of both music and speech sounds.

  6. Airborne emission measurements of SO2, NOx and particles from individual ships using sniffer technique

    Beecken, J.; Mellqvist, J.; Salo, K.; Ekholm, J.; Jalkanen, J.-P.

    2013-12-01

    A dedicated system for airborne ship emission measurements of SO2, NOx and particles has been developed and used from several small aircrafts. The system has been adapted for fast response measurements at 1 Hz and the use of several of the instruments is unique. The uncertainty of the given data is about 20.3% for SO2 and 23.8% for NOx emission factors. Multiple measurements of 158 ships measured from the air on the Baltic and North Sea during 2011 and 2012 show emission factors of 18.8 ± 6.5 g kgfuel-1, 66.6 ± 23.4 g kgfuel-1, and 1.8 ± 1.3 × 1016 particles kgfuel-1 for SO2, NOx and particle number respectively. The particle size distributions were measured for particle diameters between 15 and 560 nm. The mean sizes of the particles are between 50 and 62 nm dependent on the distance to the source and the number size distribution is mono-modal. Concerning the sulfur fuel content 85% of the ships comply with the IMO limits. The sulfur emission has decreased compared to earlier measurements from 2007 to 2009. The presented method can be implemented for regular ship compliance monitoring.

  7. Airborne emission measurements of SO2 , NOx and particles from individual ships using a sniffer technique

    Beecken, J.; Mellqvist, J.; Salo, K.; Ekholm, J.; Jalkanen, J.-P.

    2014-07-01

    A dedicated system for airborne ship emission measurements of SO2, NOx and particles has been developed and used from several small aircraft. The system has been adapted for fast response measurements at 1 Hz, and the use of several of the instruments is unique. The uncertainty of the given data is about 20% for SO2 and 24% for NOx emission factors. The mean values with one standard deviation for multiple measurements of 158 ships measured from the air on the Baltic and North Sea during 2011 and 2012 show emission factors of 18.8 ± 6.5 g kg-1 fuel , 66.6 ± 23.4 g kg-1 fuel and 1.8 ± 1.3 1016 particles kg-1 fuel for SO2, NOx and particle number, respectively. The particle size distributions were measured for particle diameters between 15 and 560 nm. The mean sizes of the particles are between 45 and 54 nm dependent on the distance to the source, and the number size distribution is monomodal. Concerning the sulfur fuel content, around 85% of the monitored ships comply with the International Maritime Organization (IMO) limits. The reduction of the sulfur emission control area (SECA) limit from 1.5 to 1% in 2010 appears to have contributed to reduction of sulfur emissions that were measured in earlier studies from 2007 to 2009. The presented method can be implemented for regular ship compliance monitoring.

  8. Sterility test by radiometric technique

    Faruq, Muhammad

    1980-01-01

    Sterility test of pharmaceuticals can be carried out by the application of pharmacopoeia and radiometric technique. In Indonesia the application of pharmacopoeia technique is carried out through liquid germination for aerobacteria and for fungus and yeast. Radiometric technique is applied to autotrop and heterotrop bacteria. (SMN)

  9. Repeatability and reproducibility of in situ measurements of sound reflection and airborne sound insulation index of noise barriers

    Garai, M.; Schoen, E.; Behler, G.; Bragado, B.; Chudalla, M.; Conter, M.; Defrance, J.; Demizieux, P.; Glorieux, C.; Guidorzi, P.

    2014-01-01

    In Europe, in situ measurements of sound reflection and airborne sound insulation of noise barriers are usually done according to CEN/TS 1793-5. This method has been improved substantially during the EU funded QUIESST collaborative project. Within the same framework, an inter-laboratory test has

  10. Modeling response variation for radiometric calorimeters

    Mayer, R.L. II.

    1986-01-01

    Radiometric calorimeters are widely used in the DOE complex for accountability measurements of plutonium and tritium. Proper characterization of response variation for these instruments is, therefore, vital for accurate assessment of measurement control as well as for propagation of error calculations. This is not difficult for instruments used to measure items within a narrow range of power values; however, when a single instrument is used to measure items over a wide range of power values, improper estimates of uncertainty can result since traditional error models for radiometric calorimeters assume that uncertainty is not a function of sample power. This paper describes methods which can be used to accurately estimate random response variation for calorimeters used to measure items over a wide range of sample powers. The model is applicable to the two most common modes of calorimeter operation: heater replacement and servo control. 5 refs., 4 figs., 1 tab

  11. Airborne gamma ray measurements conducted during an international trial in Finland

    Sanderson, D.C.W.; Allyson, J.D.; McConville, P.; Murphy, S.; Smith, J.

    1997-01-01

    The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams' quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean 137 Cs deposition of 64.4±24.4 kBq m -2 , based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated 137 Cs and 60 Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity 60 Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated 192 Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The 99m Tc was located using a ratio of low energy integrals from the NaI spectra. (EG)

  12. Airborne gamma ray measurements conducted during an international trial in Finland

    Sanderson, D.C.W.; Allyson, J.D.; McConville, P.; Murphy, S.; Smith, J. [Scottish Univ. Research and Reactor Centre, Glasgow, Scotland (United Kingdom)

    1997-12-31

    The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams` quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean {sup 137}Cs deposition of 64.4{+-}24.4 kBq m{sup -2}, based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated {sup 137}Cs and {sup 60}Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity {sup 60}Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated {sup 192}Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The {sup 99m}Tc was located using a ratio of low energy integrals from the NaI spectra. (EG). 28 refs.

  13. Airborne gamma ray measurements conducted during an international trial in Finland

    Sanderson, D C.W.; Allyson, J D; McConville, P; Murphy, S; Smith, J [Scottish Univ. Research and Reactor Centre, Glasgow, Scotland (United Kingdom)

    1998-12-31

    The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams` quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean {sup 137}Cs deposition of 64.4{+-}24.4 kBq m{sup -2}, based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated {sup 137}Cs and {sup 60}Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity {sup 60}Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated {sup 192}Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The {sup 99m}Tc was located using a ratio of low energy integrals from the NaI spectra. (EG). 28 refs.

  14. Multi-image Matching of Airborne SAR Imagery by SANCC

    DING Hao

    2015-03-01

    Full Text Available In order to improve accuracy of SAR matching, a multi-image matching method based on sum of adaptive normalized cross-correlation (SANCC is proposed. It utilizes geometrical and radiometric information of multi-baselinesynthetic aperture radar (SARimages effectively. Firstly, imaging parameters, platform parameters and approximate digital surface model (DSM are used to predict matching line. Secondly, similarity and proximity in Gestalt theory are introduced to SANCC, and SANCC measures of potential matching points along the matching line are calculated. Thirdly, multi-image matching results and object coordinates of matching points are obtained by winner-take-all (WTA optimization strategy. The approach has been demonstrated with airborne SAR images acquired by a Chinese airborne SAR system (CASMSAR system. The experimental results indicate that the proposed algorithm is effective for providing dense and accuracy matching points, reducing the number of mismatches caused by repeated textures, and offering a better solution to match in poor textured areas.

  15. Laboratory calibrations of airborne gamma-ray spectrometers. Measurements and discussions of important parameters

    Korsbech, U.

    1994-02-01

    This report is the fourth of reports from The Department of Electrophysics covering measurement and interpretation of airborne gamma-spectrometry measurements. It describes different topics concerning the construction of a suitable calibration setup in the laboratory. The goal is to build a simple and cheap laboratory setup that can produce most of the gamma-ray data needed for an interpretation of spectra measured 50 to 120 m above ground level. A simple calibration setup has been build and tested. It may produce gamma-ray spectra similar to those measured in the air - from surface contamination with artificial nuclides and from 'bulk' natural radioactivity. It is possible to investigate the influence of the air above an aircraft carrying the detector (skyshine: scattering of gamma photons in the air above the detector). In order to reduce the influence of non-detected pile-up the count rates are kept low without reaching levels where the background spectra (to be subtracted) would cause unacceptable counting statistical fluctuations. Sources selected for the calibrations are heavy minerals sand (with thorium and uranium), potassium nitrate (with 40 K). These sources are 'bulk sources' of natural radioactivity. Cesium-137 has been selected as the basic artifical surface contamination nuclide. The report also discusses methods for comparing two spectra a priori assumed equal. Finally the properties of some materials that could be used as 'air-substitutes' in the calibration setup have been tested with respect to stability against moisture sorption. (au)

  16. Automated method for measuring the extent of selective logging damage with airborne LiDAR data

    Melendy, L.; Hagen, S. C.; Sullivan, F. B.; Pearson, T. R. H.; Walker, S. M.; Ellis, P.; Kustiyo; Sambodo, Ari Katmoko; Roswintiarti, O.; Hanson, M. A.; Klassen, A. W.; Palace, M. W.; Braswell, B. H.; Delgado, G. M.

    2018-05-01

    Selective logging has an impact on the global carbon cycle, as well as on the forest micro-climate, and longer-term changes in erosion, soil and nutrient cycling, and fire susceptibility. Our ability to quantify these impacts is dependent on methods and tools that accurately identify the extent and features of logging activity. LiDAR-based measurements of these features offers significant promise. Here, we present a set of algorithms for automated detection and mapping of critical features associated with logging - roads/decks, skid trails, and gaps - using commercial airborne LiDAR data as input. The automated algorithm was applied to commercial LiDAR data collected over two logging concessions in Kalimantan, Indonesia in 2014. The algorithm results were compared to measurements of the logging features collected in the field soon after logging was complete. The automated algorithm-mapped road/deck and skid trail features match closely with features measured in the field, with agreement levels ranging from 69% to 99% when adjusting for GPS location error. The algorithm performed most poorly with gaps, which, by their nature, are variable due to the unpredictable impact of tree fall versus the linear and regular features directly created by mechanical means. Overall, the automated algorithm performs well and offers significant promise as a generalizable tool useful to efficiently and accurately capture the effects of selective logging, including the potential to distinguish reduced impact logging from conventional logging.

  17. Vertical profiles of urban aerosol complex refractive index in the frame of ESQUIF airborne measurements

    Raut, J.-C.; Chazette, P.

    2008-02-01

    A synergy between lidar, sunphotometer and in situ measurements has been applied to airborne observations performed during the Etude et Simulation de la QUalité de l'air en Ile-de-France (ESQUIF), enabling the retrieval of vertical profiles for the aerosol complex refractive index (ACRI) and single-scattering albedo with a vertical resolution of 200 m over Paris area. The averaged value over the entire planetary boundary layer (PBL) for the ACRI is close to 1.51(±0.02)-i0.017(±0.003) at 532 nm. The single-scattering albedo of the corresponding aerosols is found to be ~0.9 at the same wavelength. A good agreement is found with previous studies for urban aerosols. A comparison of vertical profiles of ACRI with simulations combining in situ measurements and relative humidity (RH) profiles has highlighted a modification in aerosol optical properties linked to their history and the origin of the air mass. The determination of ACRI in the atmospheric column enabled to retrieve vertical profiles of extinction coefficient in accordance with lidar profiles measurements.

  18. Wildfire smoke in the Siberian Arctic in summer: source characterization and plume evolution from airborne measurements

    P. Ciais

    2009-12-01

    Full Text Available We present airborne measurements of carbon dioxide (CO2, carbon monoxide (CO, ozone (O3, equivalent black carbon (EBC and ultra fine particles over North-Eastern Siberia in July 2008 performed during the YAK-AEROSIB/POLARCAT experiment. During a "golden day" (11 July 2008 a number of biomass burning plumes were encountered with CO mixing ratio enhancements of up to 500 ppb relative to a background of 90 ppb. Number concentrations of aerosols in the size range 3.5–200 nm peaked at 4000 cm−3 and the EBC content reached 1.4 μg m−3. These high concentrations were caused by forest fires in the vicinity of the landing airport in Yakutsk where measurements in fresh smoke could be made during the descent. We estimate a combustion efficiency of 90 ± 3% based on CO and CO2 measurements and a CO emission factor of 65.5 ± 10.8 g CO per kilogram of dry matter burned. This suggests a potential increase in the average northern hemispheric CO mixing ratio of 3.0–7.2 ppb per million hectares of Siberian forest burned. For BC, we estimate an emission factor of 0.52 ± 0.07 g BC kg−1, comparable to values reported in the literature. The emission ratio of ultra-fine particles (3.5–200 nm was 26 cm−3 (ppb CO−1, consistent with other airborne studies.

    The transport of identified biomass burning plumes was investigated using the FLEXPART Lagrangian model. Based on sampling of wildfire plumes from the same source but with different atmospheric ages derived from FLEXPART, we estimate that the e-folding lifetimes of EBC and ultra fine particles (between 3.5 and 200 nm in size against removal and growth processes are 5.1 and 5.5 days respectively, supporting lifetime estimates used in various modelling studies.

  19. Measurements of airborne short-lived radioactivity concentration in a PET facility at a national University hospital

    Saito, Tadashi

    2006-01-01

    National universities in Japan became under regulation of Industrial Safety and Health Law since 2004FY. One of the legal obligations is working environment measurements such as airborne radioactivity concentration in the rooms where employees handle unsealed radiation sources. Both in 2004FY and in 2005FY, measurements of airborne radioactivity concentration were carried out by two different agencies. The most prominent difference among them is the measurement for short-lived PET nuclides. In 2004FY, one agency measured the radioactivity with a Ge spectrometer at its own laboratory, whereas, in 2005FY, the other agency brought a NaI scintillation counter for gross gamma counting to the Hospital. It can be shown that detection limits for short-lived PET nuclides are in principle almost the same in both methods. It is also found that, in the actual case, gamma spectrometry with a Ge spectrometer is superior in judgement of detection of the radioactivity. (author)

  20. Emerging Technologies and Synergies for Airborne and Space-Based Measurements of Water Vapor Profiles

    Nehrir, Amin R.; Kiemle, Christoph; Lebsock, Mathew D.; Kirchengast, Gottfried; Buehler, Stefan A.; Löhnert, Ulrich; Liu, Cong-Liang; Hargrave, Peter C.; Barrera-Verdejo, Maria; Winker, David M.

    2017-11-01

    A deeper understanding of how clouds will respond to a warming climate is one of the outstanding challenges in climate science. Uncertainties in the response of clouds, and particularly shallow clouds, have been identified as the dominant source of the discrepancy in model estimates of equilibrium climate sensitivity. As the community gains a deeper understanding of the many processes involved, there is a growing appreciation of the critical role played by fluctuations in water vapor and the coupling of water vapor and atmospheric circulations. Reduction of uncertainties in cloud-climate feedbacks and convection initiation as well as improved understanding of processes governing these effects will result from profiling of water vapor in the lower troposphere with improved accuracy and vertical resolution compared to existing airborne and space-based measurements. This paper highlights new technologies and improved measurement approaches for measuring lower tropospheric water vapor and their expected added value to current observations. Those include differential absorption lidar and radar, microwave occultation between low-Earth orbiters, and hyperspectral microwave remote sensing. Each methodology is briefly explained, and measurement capabilities as well as the current technological readiness for aircraft and satellite implementation are specified. Potential synergies between the technologies are discussed, actual examples hereof are given, and future perspectives are explored. Based on technical maturity and the foreseen near-mid-term development path of the various discussed measurement approaches, we find that improved measurements of water vapor throughout the troposphere would greatly benefit from the combination of differential absorption lidar focusing on the lower troposphere with passive remote sensors constraining the upper-tropospheric humidity.

  1. Atmospheric Airborne Pressure Measurements Using the Oxygen A Band for the ASCENDS Mission

    Riris, Haris; Rodriguez, Mike; Stephen, Mark; Hasselbrack, William; Allan, Graham; Mao, Jiamping,; Kawa, Stephan R.; Weaver, Clark J.

    2011-01-01

    We report on airborne atmospheric pressure measurements using new fiber-based laser technology and the oxygen A-band at 765 nm. Remote measurements of atmospheric temperature and pressure are required for a number of NASA Earth science missions and specifically for the Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve predictions on any future climate change. The ultimate goal of a CO2 remote sensing mission, such as ASCENDS, is to derive the CO2 concentration in the atmosphere in terms of mole fraction in unit of parts-per-million (ppmv) with regard to dry air. Therefore, both CO2 and the dry air number of molecules in the atmosphere are needed in deriving this quantity. O2 is a stable molecule and uniformly mixed in the atmosphere. Measuring the O2 absorption in the atmosphere can thus be used to infer the dry air number of molecules and then used to calculate CO2 concentration. With the knowledge of atmospheric water vapor, we can then estimate the total surface pressure needed for CO2 retrievals. Our work, funded by the ESTO IIP program, uses fiber optic technology and non-linear optics to generate 765 nm laser radiation coincident with the Oxygen A-band. Our pulsed, time gated technique uses several on- and off-line wavelengths tuned to the O2 absorption line. The choice of wavelengths allows us to measure the pressure by using two adjacent O2 absorptions in the Oxygen A-band. Our retrieval algorithm fits the O2 lineshapes and derives the pressure. Our measurements compare favorably with a local weather monitor mounted outside our laboratory and a local weather station.

  2. In situ real-time measurement of physical characteristics of airborne bacterial particles

    Jung, Jae Hee; Lee, Jung Eun

    2013-12-01

    Bioaerosols, including aerosolized bacteria, viruses, and fungi, are associated with public health and environmental problems. One promising control method to reduce the harmful effects of bioaerosols is thermal inactivation via a continuous-flow high-temperature short-time (HTST) system. However, variations in bioaerosol physical characteristics - for example, the particle size and shape - during the continuous-flow inactivation process can change the transport properties in the air, which can affect particle deposition in the human respiratory system or the filtration efficiency of ventilation systems. Real-time particle monitoring techniques are a desirable alternative to the time-consuming process of microscopic analysis that is conventionally used in sampling and particle characterization. Here, we report in situ real-time optical scattering measurements of the physical characteristics of airborne bacteria particles following an HTST process in a continuous-flow system. Our results demonstrate that the aerodynamic diameter of bacterial aerosols decreases when exposed to a high-temperature environment, and that the shape of the bacterial cells is significantly altered. These variations in physical characteristics using optical scattering measurements were found to be in agreement with the results of scanning electron microscopy analysis.

  3. Instrument for long-path spectral extinction measurements in air: application to sizing of airborne particles

    Paganini, Enrico; Trespidi, Franco; Ferri, Fabio

    2001-01-01

    A novel instrument that is capable of taking spectral extinction measurements over long optical paths (approximately 1-100 m) in the UV, visible, and IR ranges is described. The instrument is fully automated, and the extinction spectrum is acquired in almost real time (approximately 5-10 s) with a resolution of ∼3 nm. Its sensitivity and accuracy were estimated by tests carried out in a clean room that showed that, for optical paths between 50 and 100 m, the extinction coefficient can be detected at levels of ∼10 -5 m -1 . Tests carried out on calibrated latex particles showed that, when it was combined with an appropriate inversion method, the technique could be profitably applied to characterize airborne particulate distributions. By carrying out measurements over optical paths of ∼100 m, the instrument is also capable of detecting extinction coefficients that are due to aerosol concentrations well below the limits imposed by the European Economic Community for atmospheric pollution (150 μg/m3). Scaled over optical paths of ∼10 m, the limit imposed for particle emissions from industrial plants (10 mg/m3) can also be detected sensitively

  4. Taking Stock of Circumboreal Forest Carbon With Ground Measurements, Airborne and Spaceborne LiDAR

    Neigh, Christopher S. R.; Nelson, Ross F.; Ranson, K. Jon; Margolis, Hank A.; Montesano, Paul M.; Sun, Guoqing; Kharuk, Viacheslav; Naesset, Erik; Wulder, Michael A.; Andersen, Hans-Erik

    2013-01-01

    The boreal forest accounts for one-third of global forests, but remains largely inaccessible to ground-based measurements and monitoring. It contains large quantities of carbon in its vegetation and soils, and research suggests that it will be subject to increasingly severe climate-driven disturbance. We employ a suite of ground-, airborne- and space-based measurement techniques to derive the first satellite LiDAR-based estimates of aboveground carbon for the entire circumboreal forest biome. Incorporating these inventory techniques with uncertainty analysis, we estimate total aboveground carbon of 38 +/- 3.1 Pg. This boreal forest carbon is mostly concentrated from 50 to 55degN in eastern Canada and from 55 to 60degN in eastern Eurasia. Both of these regions are expected to warm >3 C by 2100, and monitoring the effects of warming on these stocks is important to understanding its future carbon balance. Our maps establish a baseline for future quantification of circumboreal carbon and the described technique should provide a robust method for future monitoring of the spatial and temporal changes of the aboveground carbon content.

  5. Surface and airborne measurements of organosulfur and methanesulfonate over the western United States and coastal areas

    Sorooshian, Armin; Crosbie, Ewan; Maudlin, Lindsay C.; Youn, Jong-Sang; Wang, Zhen; Shingler, Taylor; Ortega, Amber M.; Hersey, Scott; Woods, Roy K.

    2015-08-01

    This study reports on ambient measurements of organosulfur (OS) and methanesulfonate (MSA) over the western United States and coastal areas. Particulate OS levels are highest in summertime and generally increase as a function of sulfate (a precursor) and sodium (a marine tracer) with peak levels at coastal sites. The ratio of OS to total sulfur is also highest at coastal sites, with increasing values as a function of normalized difference vegetation index and the ratio of organic carbon to elemental carbon. Correlative analysis points to significant relationships between OS and biogenic emissions from marine and continental sources, factors that coincide with secondary production, and vanadium due to a suspected catalytic role. A major OS species, methanesulfonate (MSA), was examined with intensive field measurements, and the resulting data support the case for vanadium's catalytic influence. Mass size distributions reveal a dominant MSA peak between aerodynamic diameters of 0.32-0.56 µm at a desert and coastal site with nearly all MSA mass (≥84%) in submicrometer sizes; MSA:non-sea-salt sulfate ratios vary widely as a function of particle size and proximity to the ocean. Airborne data indicate that relative to the marine boundary layer, particulate MSA levels are enhanced in urban and agricultural areas and also the free troposphere when impacted by biomass burning. Some combination of fires and marine-derived emissions leads to higher MSA levels than either source alone. Finally, MSA differences in cloud water and out-of-cloud aerosol are discussed.

  6. Study of the use of a Phoswich detector for aerial radiometric surveys

    Schneid, E.J.; Lagin, L.J.

    1981-09-01

    Large volume, actively shielded Phoswich detector configurations were investigated for application in airborne radiometric survey systems in order to increase the sensitivity to ground-level potassium, uranium, and thorium compared to conventional NaI detectors of similar sizes. One Phoswich configuration was fabricated and flight tested. The flight measurements with the Phoswich detector and a conventional NaI detector utilized the Bendix Field Engineering Corporation - US Department of Energy/Grand Junction Office Walker Field Aerial Radiometric Survey Calibration Facility, the DOE dynamic test range, and a region in the southwest portion of the Lubbock, Texas, Quadrangle. The tests demonstrated that the Phoswich detector can function in an operational environment and does provide greater sensitivity to ground-level potassium, uranium, and thorium concentration than the conventional NaI detector. The multicrystal configuration for the Phoswich detector provided the capability to simultaneously measure the atmospheric radon background without the need of heavy lead shields. The flight tests indicated that the Phoswich detector has directional discrimination capability not available with conventional NaI detector systems. This directional capability can be used to distinguish the location, relative to the aircraft, of localized strong sources of radiation

  7. Design and use of concrete pads for the calibration of radiometric survey instrumentation

    Loevborg, L.

    1984-10-01

    A gamma-ray spectrometer for use in geological exploration possesses four stripping ratios and three window sensitivities which must be determined to make the instrumentation applicable for field assay or airborne measurement of potassium, uranium, and thorium contents in the ground. Survey organizations in many parts of the world perform the instrument calibration using large pads of concrete which simulate a plane ground of known radioelement concentration. Calibration and monitoring trials with twelve facilities in ten countries prove that moisture absorption, radon exhalation, and particle-size effects can offset a radiometric grade assigned to concrete whose aggregate contains an embedded radioactive mineral. These and other calibration problems are discussed from a combined theoretical and practical viewpoint

  8. The construction of a radiometric calibration facility at Lanseria Airport, Republic of South Africa

    Corner, B.; Smit, C.J.B.

    1983-08-01

    The construction of standard sources suitable for the calibration of airborne and truck-mounted gamma-spectrometer systems is described. Four sources were built, three of which were doped with preselected quantities of uranium, thorium or potassium. A fourth source was left barren so as to provide a measure of the background radiation in the area. The sources are 8 m in diameter, 0,35 m thick and are recessed into the disused northern portion of runway 17 at Lanseria Airport, north of Johannesburg. Adopted concentrations of the major radioelements in the sources are: 6,10 % k 2 O in the potasssium source, 67,0 ppm U 3 O 8 in the uranium source (radiometric), 158 ppm ThO 2 in the thorium source

  9. Hardware Design for a Fixed-Wing Airborne Gravity Measurement System

    1986-12-22

    worldwide navigation system currently available that is sufficiently accurate for deter- mining Eotvos correction in airborne gravimetry is the Global...better in defining the strength of precipitation . The radar display is compact enough to be mounted on the cockpit, thus giving the pilots better...of the proposed AGMS version 3 MISCELLANEOUS AIRCRAFT CONSIDERATIONS Autopilot One of the most important considerations in airborne gravimetry is

  10. Radiometric report for a blast furnace tracing with radioactive isotopes

    Tanase, G.; Tanase, M.

    1995-01-01

    One of the methods to monitor refractory wall of blast furnace is its tracing with radioactive isotopes. The tracer isotope can be detected by two ways: the external dosimetric measurement at the armour of the blast furnace and/or the radiometric measurement of the iron sample charge by charge. Any change in radiometric situation of tracer radioisotope is recorded in a radiometric report. This paper presents an original concept of radiometric report based upon PARADOX and CORELDRAW soft kits. Their advantage are: quick and easy changes, easy recording of current radioactivity of tracer isotope, short history of changes, visual mapping of the tracer isotope and others. In this way we monitored 6 blast furnaces and more than 180 radioactive sources

  11. High-accuracy continuous airborne measurements of greenhouse gases (CO2 and CH4) during BARCA

    Chen, H.; Winderlich, J.; Gerbig, C.; Hoefer, A.; Rella, C. W.; Crosson, E. R.; van Pelt, A. D.; Steinbach, J.; Kolle, O.; Beck, V.; Daube, B. C.; Gottlieb, E. W.; Chow, V. Y.; Santoni, G. W.; Wofsy, S. C.

    2009-12-01

    High-accuracy continuous measurements of greenhouse gases (CO2 and CH4) during the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) phase B campaign in Brazil in May 2009 were accomplished using a newly available analyzer based on the cavity ring-down spectroscopy (CRDS) technique. This analyzer was flown without a drying system or any in-flight calibration gases. Water vapor corrections associated with dilution and pressure-broadening effects for CO2 and CH4 were derived from laboratory experiments employing measurements of water vapor by the CRDS analyzer. Before the campaign, the stability of the analyzer was assessed by laboratory tests under simulated flight conditions. During the campaign, a comparison of CO2 measurements between the CRDS analyzer and a nondispersive infrared (NDIR) analyzer on board the same aircraft showed a mean difference of 0.22±0.09 ppm for all flights over the Amazon rain forest. At the end of the campaign, CO2 concentrations of the synthetic calibration gases used by the NDIR analyzer were determined by the CRDS analyzer. After correcting for the isotope and the pressure-broadening effects that resulted from changes of the composition of synthetic vs. ambient air, and applying those concentrations as calibrated values of the calibration gases to reprocess the CO2 measurements made by the NDIR, the mean difference between the CRDS and the NDIR during BARCA was reduced to 0.05±0.09 ppm, with the mean standard deviation of 0.23±0.05 ppm. The results clearly show that the CRDS is sufficiently stable to be used in flight without drying the air or calibrating in flight and the water corrections are fully adequate for high-accuracy continuous airborne measurements of CO2 and CH4.

  12. Effect of micro-scale wind on the measurement of airborne pollen concentrations using volumetric methods on a building rooftop

    Miki, Kenji; Kawashima, Shigeto; Fujita, Toshio; Nakamura, Kimihito; Clot, Bernard

    2017-06-01

    Evaluating airborne pollen concentrations is important for the understanding of the spatiotemporal dispersion of pollen grains. Using two identical pollen monitors in parallel, we performed two experiments in order to study the influences of a) the physical characteristics (orientation) of the air inlet and b) the presence of obstacles in proximity to the monitors on airborne pollen concentration data. The first experiment consisted of an evaluation of airborne pollen concentrations using two different types of orifices; 1) a vertically oriented inlet and 2) a wind vane intake, both attached to the same type of automatic pollen sampler. The second experiment investigated the relationship between vertical wind speed and horizontal wind direction around an obstacle with the goal of studying the impact of micro-scale wind on pollen sampling efficiency. The results of the two experiments suggest that the wind path near an obstacle might be redirected in a vertical direction before or after the wind flows over the obstacle, which causes measurement errors of airborne pollen concentrations that are proportional to the vertical wind speed, especially when a vertically oriented inlet is used.

  13. Experimental study of the response functions of direct-reading instruments measuring surface-area concentration of airborne nanostructured particles

    Bau, Sebastien; Witschger, Olivier; Gensdarmes, Francois; Thomas, Dominique

    2009-01-01

    An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment to move forward our understanding of the hazards, the actual exposures in the workplace, and the limits of engineering controls and personal protective equipment with regard to NP. As a consequence, generating airborne NP with controlled properties constitutes an important challenge. In parallel, toxicological studies have been carried out, and most of them support the concept that surface-area could be a relevant metric for characterizing exposure to airborne NP. To provide NP surface-area concentration measurements, some direct-reading instruments have been designed, based on attachment rate of unipolar ions to NP by diffusion. However, very few information is available concerning the performances of these instruments and the parameters that could affect their responses. In this context, our work aims at characterizing the actual available instruments providing airborne NP surface-area concentration. The instruments (a- LQ1-DC, Matter Engineering; b-AeroTrak x2122 9000, TSI; c- NSAM, TSI model 3550;) are thought to be relevant for further workplace exposure characterization and monitoring. To achieve our work, an experimental facility (named CAIMAN) was specially designed, built and characterized.

  14. Experimental study of the response functions of direct-reading instruments measuring surface-area concentration of airborne nanostructured particles

    Bau, Sebastien; Witschger, Olivier [Institut National de Recherche et de Securite, INRS, Laboratoire de Metrologie des Aerosols, Rue du Morvan, CS 60027, 54519 Vandoeuvre Cedex (France); Gensdarmes, Francois [Institut de Radioprotection et de Surete Nucleaire, IRSN, Laboratoire de Physique et de Metrologie des Aerosols, BP 68, 91192 Gif-sur-Yvette Cedex (France); Thomas, Dominique [Laboratoire des Sciences du Genie Chimique, LSGC/CNRS, Nancy Universite, BP 2041, 54001 Nancy Cedex (France)], E-mail: sebastien.bau@inrs.fr

    2009-05-01

    An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment to move forward our understanding of the hazards, the actual exposures in the workplace, and the limits of engineering controls and personal protective equipment with regard to NP. As a consequence, generating airborne NP with controlled properties constitutes an important challenge. In parallel, toxicological studies have been carried out, and most of them support the concept that surface-area could be a relevant metric for characterizing exposure to airborne NP. To provide NP surface-area concentration measurements, some direct-reading instruments have been designed, based on attachment rate of unipolar ions to NP by diffusion. However, very few information is available concerning the performances of these instruments and the parameters that could affect their responses. In this context, our work aims at characterizing the actual available instruments providing airborne NP surface-area concentration. The instruments (a- LQ1-DC, Matter Engineering; b-AeroTrak{sup x2122} 9000, TSI; c- NSAM, TSI model 3550;) are thought to be relevant for further workplace exposure characterization and monitoring. To achieve our work, an experimental facility (named CAIMAN) was specially designed, built and characterized.

  15. Seagrass biomass and productivity in the Florida Keys, USA: ground-level and airborne measurements

    Yarbro, L.; Carlson, P. R., Jr.; McHan, C.; Carlson, D. F.; Hu, C.; Danielson, T.; Durnan, B.; English, D. C.; Muller-Karger, F. E.; Yates, K. K.; Herwitz, S.; Merrill, J.; Mewes, T.

    2013-12-01

    Seagrass communities serve as essential habitat for fish and shellfish, and recent research indicates that they can play a significant role in reducing ocean acidification. As part of a collaborative project funded by the NASA ROSES program and administered by the NASA UAV Collaborative, we collected hyperspectral imagery of seagrass beds and measured productivity of Thalassia testudinum at Sugarloaf Key, Florida, in May 2012, October 2012, and May 2013. Our primary goal was to evaluate the utility of hyperspectral sensors, in general, and UAV platforms, in specific, to measure seagrass health and productivity. Airborne measurements using the AISA Eagle hyperspectral imaging system were carried out simultaneously with ground measurements of Thalassia fluorescence, oxygen metabolism, growth, and biomass, as well as remote sensing reflectance and several in situ optical properties. Water depths at the study site ranged from less than 1 m to 5 m. Phytoplankton chlorophyll-a concentrations (0.09-0.72 ug l-1), ag(440) (0-0.02 m-1), and turbidity (0.12-4.1 ntu) were relatively low for all three deployments, facilitating the collection of excellent imagery and application of water-column radiative-transfer corrections. Aboveground Thalassia and macroalgal biomass, at 18 sites in the study area, ranged from 210 to 690 and 11 to 590 gDW m-2, respectively. One-sided green leaf area index of Thalassia ranged from 0.7 to 3.0. Preliminary findings show that the sensitivity of relationships between seagrass productivity and biomass parameters and remotely-sensed habitat spectra is reduced with increasing water depth and, even in shallow water, is complicated by epiphytic algae and sediment coverage of leaf surfaces.

  16. Airborne gamma spectrometry measurements in the context of the exercise ARM02

    Bucher, B.; Rybach, L.; Schwarz, G.; Baerlocher, C.

    2003-05-01

    The international exercise under the European Union project ECCOMAGS (European Coordination and Calibration of Mobile and Airborne Gamma Spectrometry) stood in the centre of the yearly airborne gamma spectrometry measurement flights which were carried out in the time of 27 -31 May 2002. The exercise was held in Southwest Scotland in the region of Dumfries and Galloway. Unfortunately due to difficulties with flight approvals for military aircrafts data could be taken in the exercise area only on the flight back to Switzerland. Immediately after returning to Switzerland the regular measurements around the nuclear power plants Beznau (KKB) and Leibstadt (KKL), around the intermediate storage facilities for radioactive waste (ZWILAG) and around the research facility Paul Scherrer Institute were performed. The flights took place in the context of the exercise ARM02 and were lead by the Swiss National Emergency Operations Centre (NAZ). Unfortunately just a few measurements in the common intercalibration areas could be taken on the flight back from the international exercise. Nevertheless comparisons of the results with those of other European teams could be made. These comparisons proved the good calibration of our equipment. On the flight back measurements were also carried out at great altitude above the sea. This data allowed to determine very well the background of the aircraft and the cosmic stripping ratios. In the context of the regular measurements in the environs of the nuclear facilities in Switzerland the areas around the nuclear power plants Beznau and Leibstadt and around the nuclear research facility Paul Scherrer Institute were measured. The results were very similar to the results of earlier measurements in the last years. The nuclear power plant Beznau couldn't be recognised on the activity maps. But the nuclear power plant Leibstadt could be identified by its direct radiation which is specific for this type of reactor (BWR). At the site of the Paul

  17. Radiometric enrichment of nonradioactive ores

    Mokrousov, V.A.; Lileev, V.A.

    1979-01-01

    Considered are the methods of mineral enrichment based on the use of the radioation of various types. The physical essence of enrichment processes is presented, their classification is given. Described are the ore properties influencing the efficiency of radiometric enrichment, methods of the properties study and estimation of ore enrichment. New possibilities opened by radiometric enrichment in the technology of primary processing of mineral raw materials are elucidated. A considerable attention is paid to the main and auxiliary equipment for radiometric enrichment. The foundations of the safety engineering are presented in a brief form. Presented are also results of investigations and practical works in the field of enrichment of ores of non-ferrous, ferrous and non-metallic minerals with the help of radiometric methods

  18. Measured and modelled concentrations and vertical profiles of airborne particulate matter within the boundary layer of a street canyon

    Colls, J.J.; Micallef, A.

    1999-01-01

    Concentrations and vertical profiles of various fractions of airborne particulate matter (suspended particulate matter (SPM), PM 10 and PM 2.5 ) have been measured over the first three metres from ground in a street canyon. Measurements were carried out using automated near real-time apparatus called the Kinetic Sequential Sampling (KSS) system. KSS system is essentially an electronically-controlled lift carrying a real-time particle monitor for sampling air sequentially, at different heights within the breathing zone, which includes all heights within the surface layer of a street canyon at which people may breathe. Data is automatically logged at the different receptor levels, for the determination of the average vertical concentration profile of airborne particulate matter. For measuring the airborne particle concentration, a Grimm Dust Monitor 1.104/5 was used. The recorded data also allows for time series analysis of airborne particulate matter concentration at different heights. Time series data and hourly-average vertical concentration profiles in the boundary layer of the confines of a street are thought to be mainly determined by traffic emissions and traffic associated processes. Hence the measured data were compared with results of a street canyon emission-dispersion model in time and space. This Street Level Air Quality (SLAQ) model employs the plume-box technique and includes modules for simulating vehicle-generated effects such as thermally- and mechanically-generated turbulence and resuspension of road dust. Environmental processes, such as turbulence resulting from surface sensible heat and the formation of sulphate aerosol from sulphur dioxide exhaust emissions, are taken into account. The paper presents an outline description of the measuring technique and model used, and a comparison of the measured and modelled data

  19. Airborne protein concentration: a key metric for type 1 allergy risk assessment-in home measurement challenges and considerations.

    Tulum, Liz; Deag, Zoë; Brown, Matthew; Furniss, Annette; Meech, Lynn; Lalljie, Anja; Cochrane, Stella

    2018-01-01

    Exposure to airborne proteins can be associated with the development of immediate, IgE-mediated respiratory allergies, with genetic, epigenetic and environmental factors also playing a role in determining the likelihood that sensitisation will be induced. The main objective of this study was to determine whether airborne concentrations of selected common aeroallergens could be quantified in the air of homes using easily deployable, commercially available equipment and analytical methods, at low levels relevant to risk assessment of the potential to develop respiratory allergies. Additionally, air and dust sampling were compared and the influence of factors such as different filter types on allergen quantification explored. Low volume air sampling pumps and DUSTREAM ® dust samplers were used to sample 20 homes and allergen levels were quantified using a MARIA ® immunoassay. It proved possible to detect a range of common aeroallergens in the home with sufficient sensitivity to quantify airborne concentrations in ranges relevant to risk assessment (Limits of Detection of 0.005-0.03 ng/m 3 ). The methodology discriminates between homes related to pet ownership and there were clear advantages to sampling air over dust which are described in this paper. Furthermore, in an adsorption-extraction study, PTFE (polytetrafluoroethylene) filters gave higher and more consistent recovery values than glass fibre (grade A) filters for the range of aeroallergens studied. Very low airborne concentrations of allergenic proteins in home settings can be successfully quantified using commercially available pumps and immunoassays. Considering the greater relevance of air sampling to human exposure of the respiratory tract and its other advantages, wider use of standardised, sensitive techniques to measure low airborne protein concentrations and how they influence development of allergic sensitisation and symptoms could accelerate our understanding of human dose-response relationships

  20. Airborne cloud condensation nuclei measurements during the 2006 Texas Air Quality Study

    Asa-Awuku, Akua; Moore, Richard H.; Nenes, Athanasios; Bahreini, Roya; Holloway, John S.; Brock, Charles A.; Middlebrook, Ann M.; Ryerson, Thomas B.; Jimenez, Jose L.; Decarlo, Peter F.; Hecobian, Arsineh; Weber, Rodney J.; Stickel, Robert; Tanner, Dave J.; Huey, Lewis G.

    2011-06-01

    Airborne measurements of aerosol and cloud condensation nuclei (CCN) were conducted aboard the National Oceanic and Atmospheric Administration WP-3D platform during the 2006 Texas Air Quality Study/Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS). The measurements were conducted in regions influenced by industrial and urban sources. Observations show significant local variability of CCN activity (CCN/CN from 0.1 to 0.5 at s = 0.43%), while variability is less significant across regional scales (˜100 km × 100 km; CCN/CN is ˜0.1 at s = 0.43%). CCN activity can increase with increasing plume age and oxygenated organic fraction. CCN measurements are compared to predictions for a number of mixing state and composition assumptions. Mixing state assumptions that assumed internally mixed aerosol predict CCN concentrations well. Assuming organics are as hygroscopic as ammonium sulfate consistently overpredicted CCN concentrations. On average, the water-soluble organic carbon (WSOC) fraction is 60 ± 14% of the organic aerosol. We show that CCN closure can be significantly improved by incorporating knowledge of the WSOC fraction with a prescribed organic hygroscopicity parameter (κ = 0.16 or effective κ ˜ 0.3). This implies that the hygroscopicity of organic mass is primarily a function of the WSOC fraction. The overall aerosol hygroscopicity parameter varies between 0.08 and 0.88. Furthermore, droplet activation kinetics are variable and 60% of particles are smaller than the size characteristic of rapid droplet growth.

  1. Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity

    T. Karl

    2009-01-01

    Full Text Available Toluene and benzene are used for assessing the ability to measure disjunct eddy covariance (DEC fluxes of Volatile Organic Compounds (VOC using Proton Transfer Reaction Mass Spectrometry (PTR-MS on aircraft. Statistically significant correlation between vertical wind speed and mixing ratios suggests that airborne VOC eddy covariance (EC flux measurements using PTR-MS are feasible. City-median midday toluene and benzene fluxes are calculated to be on the order of 14.1±4.0 mg/m2/h and 4.7±2.3 mg/m2/h, respectively. For comparison the adjusted CAM2004 emission inventory estimates toluene fluxes of 10 mg/m2/h along the footprint of the flight-track. Wavelet analysis of instantaneous toluene and benzene measurements during city overpasses is tested as a tool to assess surface emission heterogeneity. High toluene to benzene flux ratios above an industrial district (e.g. 10–15 g/g including the International airport (e.g. 3–5 g/g and a mean flux (concentration ratio of 3.2±0.5 g/g (3.9±0.3 g/g across Mexico City indicate that evaporative fuel and industrial emissions play an important role for the prevalence of aromatic compounds. Based on a tracer model, which was constrained by BTEX (BTEX– Benzene/Toluene/Ethylbenzene/m, p, o-Xylenes compound concentration ratios, the fuel marker methyl-tertiary-butyl-ether (MTBE and the biomass burning marker acetonitrile (CH3CN, we show that a combination of industrial, evaporative fuel, and exhaust emissions account for >87% of all BTEX sources. Our observations suggest that biomass burning emissions play a minor role for the abundance of BTEX compounds in the MCMA (2–13%.

  2. Airborne-Measured Spatially-Averaged Temperature and Moisture Turbulent Structure Parameters Over a Heterogeneous Surface

    Platis, Andreas; Martinez, Daniel; Bange, Jens

    2014-05-01

    Turbulent structure parameters of temperature and humidity can be derived from scintillometer measurements along horizontal paths of several 100 m to several 10 km. These parameters can be very useful to estimate the vertical turbulent heat fluxes at the surface (applying MOST). However, there are many assumptions required by this method which can be checked using in situ data, e.g. 1) Were CT2 and CQ2 correctly derived from the initial CN2 scintillometer data (structure parameter of density fluctuations or refraction index, respectively)? 2) What is the influence of the surround hetereogeneous surface regarding its footprint and the weighted averaging effect of the scintillometer method 3) Does MOST provide the correct turbulent fluxes from scintillometer data. To check these issues, in situ data from low-level flight measurements are well suited, since research aircraft cover horizontal distances in very short time (Taylor's hypothesis of a frozen turbulence structure can be applyed very likely). From airborne-measured time series the spatial series are calculated and then their structure functions that finally provide the structure parameters. The influence of the heterogeneous surface can be controlled by the definition of certain moving-average window sizes. A very useful instrument for this task are UAVs since they can fly very low and maintain altitude very precisely. However, the data base of such unmanned operations is still quite thin. So in this contribution we want to present turbulence data obtained with the Helipod, a turbulence probe hanging below a manned helicopter. The structure parameters of temperature and moisture, CT2 and CQ2, in the lower convective boundary layer were derived from data measured using the Helipod in 2003. The measurements were carried out during the LITFASS03 campaign over a heterogeneous land surface around the boundary-layer field site of the Lindenberg Meteorological Observatory-Richard-Aßmann-Observatory (MOL) of the

  3. Environmental airborn radioactivity survey around Burg El Arab Area, Western desert, Egypt

    Fouad, K.M.; Ammar, A.A.; Meleik, M.L.

    1977-01-01

    An environmental airborne radioactivity survey of approximately 250 square kilometres of Burg El Arab area was conducted by the Airborne Geophysical survey Division of the Geology and Raw Materials Department. The environmental levels of gamma radiation are measured so as to determine quickly the amount and extent of any possible future increase in radioactivity levels of the area by the proposed nuclear facility through normal operations or any accident that may occur. The aerial radiometric measurements were obtained by a continuously recording airborne scintillometer type RVS-1. installed in an Antonoff-2 aircraft, flying at an average speed of 170 Km/h, at a nominal ground clearance of 50 m. The survey was carried out along 84 parallel flight lines directed N-S, and spaced 250 m apart. The area is shown on the geological map as composed of four lithological units. The analysis of the data has proved that these units correspond to six distinct levels of characteristic radioactivity, as two of the lithological units could each be separated into two radioactivity levels on the basis of the radioactivity pattern. The six radiometric levels are, from north to south, beach limy sediments (15 to 101. and 97 to 191 cps), detrital limestone (201 to 354 cpt), saline lakes and salt deposits (262 to 444 cps), and alluvial deposits (307 to 308 and 412 to 742 cps)

  4. Methane emissions from a Californian landfill, determined from airborne remote sensing and in situ measurements

    Krautwurst, Sven; Gerilowski, Konstantin; Jonsson, Haflidi H.; Thompson, David R.; Kolyer, Richard W.; Iraci, Laura T.; Thorpe, Andrew K.; Horstjann, Markus; Eastwood, Michael; Leifer, Ira; Vigil, Samuel A.; Krings, Thomas; Borchardt, Jakob; Buchwitz, Michael; Fladeland, Matthew M.; Burrows, John P.; Bovensmann, Heinrich

    2017-09-01

    Fugitive emissions from waste disposal sites are important anthropogenic sources of the greenhouse gas methane (CH4). As a result of the growing world population and the recognition of the need to control greenhouse gas emissions, this anthropogenic source of CH4 has received much recent attention. However, the accurate assessment of the CH4 emissions from landfills by modeling and existing measurement techniques is challenging. This is because of inaccurate knowledge of the model parameters and the extent of and limited accessibility to landfill sites. This results in a large uncertainty in our knowledge of the emissions of CH4 from landfills and waste management. In this study, we present results derived from data collected during the research campaign COMEX (CO2 and MEthane eXperiment) in late summer 2014 in the Los Angeles (LA) Basin. One objective of COMEX, which comprised aircraft observations of methane by the remote sensing Methane Airborne MAPper (MAMAP) instrument and a Picarro greenhouse gas in situ analyzer, was the quantitative investigation of CH4 emissions. Enhanced CH4 concentrations or CH4 plumes were detected downwind of landfills by remote sensing aircraft surveys. Subsequent to each remote sensing survey, the detected plume was sampled within the atmospheric boundary layer by in situ measurements of atmospheric parameters such as wind information and dry gas mixing ratios of CH4 and carbon dioxide (CO2) from the same aircraft. This was undertaken to facilitate the independent estimation of the surface fluxes for the validation of the remote sensing estimates. During the COMEX campaign, four landfills in the LA Basin were surveyed. One landfill repeatedly showed a clear emission plume. This landfill, the Olinda Alpha Landfill, was investigated on 4 days during the last week of August and first days of September 2014. Emissions were estimated for all days using a mass balance approach. The derived emissions vary between 11.6 and 17.8 kt CH4 yr-1

  5. Nitrous Oxide (N2O) Emissions from California based on 2010 CalNex Airborne Measurements

    Xiang, B.; Miller, S.; Kort, E. A.; Santoni, G. W.; Daube, B.; Commane, R.; Angevine, W. M.; Ryerson, T. B.; Trainer, M.; Andrews, A. E.; Nehrkorn, T.; Tian, H.; Wofsy, S. C.

    2012-12-01

    Nitrous oxide (N2O) is an important gas for climate and for stratospheric chemistry, with an atmospheric lifetime exceeding 100 years. Global concentrations have increased steadily since the 18th century, apparently due to human-associated emissions, principally from application of nitrogen fertilizers. However, quantitative studies of agricultural emissions at large spatial scales are lacking, inhibited by the difficulty of measuring small enhancements of atmospheric concentrations. Here we derive regional emission rates for N2O in the Central Valley of California, based on analysis of in-situ airborne atmospheric observations collected using a quantum cascade laser spectrometer. The data were obtained on board the NOAA P-3 research aircraft during the CalNex (California Research at the Nexus of Air Quality and Climate Change) program in May and June, 2010. We coupled WRF (Weather Research and Forecasting) model to STILT (Stochastic Time-Inverted Lagrangian Transport) to link our in-situ observations to surface emissions, and then used a variety of statistical methods to identify source areas and to extract optimized emission rates from the inversion. Our results support the view that fertilizer application is the largest source of N2O in the Central Valley. But the spatial distribution of derived surface emissions, based on California land use and activity maps, was very different than indicated in the leading emissions inventory (EDGAR 4.0), and our estimated total emission flux of N2O for California during the study period was 3 - 4 times larger than EDGAR and other inventories.

  6. A mini backscatter lidar for airborne measurements in the framework of DACCIWA

    Chazette, Patrick; Totems, Julien; Flamant, Cyrille; Shang, Xiaoxia; Denjean, Cyrielle; Meynadier, Rémi; Perrin, Thierry; Laurens, Marc

    2017-04-01

    During the international campaign of the European program Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA), investigating the relationship between weather, climate and air pollution in southern West Africa, a mini backscatter lidar was embedded on the French research aircraft (ATR42) of the Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE). This implementation was made possible thanks to the support of the Centre National d'Etude Spatial (CNES), with the aim of assessing the relative relevance of airborne or spaceborne (e.g. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations, CALIPSO) remote sensing instruments. The lidar complemented the various in-situ observations carried out on the plane, by identifying the aerosol layers in the atmospheric column below the aircraft, and bringing strong constraints for the validation of other measurements. The field campaign took place from 27 to 16 July 2016 from Lomé, Togo. The aircraft conducted flights between 1 km and 5 km above the mean sea level (amsl), allowing the coupling of in situ and remote sensing data to assess the properties of the aerosol layers. Aerosol plumes of different origins were identified using the coupling between the lidar cross-polarized channels, satellite observations and a set of back trajectories analyses. During several flights, depolarizing aerosol layers from the northeast were observed between 2.5 and 4 km amsl, which highlight the significant contribution of dust-like particles to the aerosol load in the coastal region. Conversely, air masses originating from the east-southeast were loaded with a mixing of biomass burning and pollution aerosols. The former originated from Central Africa and the latter from human activities in and around large cities (Lomé). The flight sampling strategy and related lidar investigations will be presented and discussed.

  7. Comparison of Lyman-alpha and LI-COR infrared hygrometers for airborne measurement of turbulent fluctuations of water vapour

    Lampert, Astrid; Hartmann, Jörg; Pätzold, Falk; Lobitz, Lennart; Hecker, Peter; Kohnert, Katrin; Larmanou, Eric; Serafimovich, Andrei; Sachs, Torsten

    2018-05-01

    To investigate if the LI-COR humidity sensor can be used as a replacement of the Lyman-alpha sensor for airborne applications, the measurement data of the Lyman-alpha and several LI-COR sensors are analysed in direct intercomparison flights on different airborne platforms. One vibration isolated closed-path and two non-isolated open-path LI-COR sensors were installed on a Dornier 128 twin engine turbo-prop aircraft. The closed-path sensor provided absolute values and fluctuations of the water vapour mixing ratio in good agreement with the Lyman-alpha. The signals of the two open-path sensors showed considerable high-frequency noise, and the absolute value of the mixing ratio was observed to drift with time in this vibrational environment. On the helicopter-towed sensor system Helipod, with very low vibration levels, the open-path LI-COR sensor agreed very well with the Lyman-alpha sensor over the entire frequency range up to 3 Hz. The results show that the LI-COR sensors are well suited for airborne measurements of humidity fluctuations, provided that a vibrationless environment is given, and this turns out to be more important than close sensor spacing.

  8. Exploring a Black Body Source as an Absolute Radiometric Calibration Standard and Comparison with a NIST Traced Lamp Standard

    Green, Robert O.; Chrien, Thomas; Sarture, Chuck

    2001-01-01

    Radiometric calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) is required for the scientific research and application objectives pursued with the spectroscopic measurements. Specifically calibration is required for: inter-comparison of AVIRIS data measured at different locations and at different times; analysis of AVIRIS data with data measured by other instruments; and analysis of AVIRIS data in conjunction with computer models. The primary effect of radiometric calibration is conversion of AVIRIS instrument response values (digitized numbers, or DN) to units of absolute radiance. For example, a figure shows the instrument response spectrum measured by AVIRIS over a portion of Rogers Dry Lake, California, and another figure shows the same spectrum calibrated to radiance. Only the calibrated spectrum may be quantitatively analyzed for science research and application objectives. Since the initial development of the AVIRIS instrument-radiometric calibration has been based upon a 1000-W irradiance lamp with a calibration traced to the National Institute of Standards and Technology (NIST). There are several advantages to this irradiance-lamp calibration approach. First, the considerable effort of NIST backs up the calibration. Second, by changing the distance to the lamp, the output can closely span the radiance levels measured by AVIRIS. Third, this type of standard is widely used. Fourth, these calibrated lamps are comparatively inexpensive. Conversely, there are several disadvantages to this approach as well. First, the lamp is not a primary standard. Second, the lamp output characteristics may change in an unknown manner through time. Third, it is difficult to assess, constrain, or improve the calibration uncertainty delivered with the lamp. In an attempt to explore the effect and potentially address some of these disadvantages a set of analyses and measurements comparing an irradiance lamp with a black-body source have been completed

  9. A report of airbone radiometric and magnetic test survey

    Koo, J.H.; Park, Y.S.; Woo, S.M.

    1982-01-01

    By the end of Oct. 1981, a complete set of GeoMetrics' air-borne radiometric and magnetic survey system was purchased by KIER using the ADB loan, and it took one week from Nov. 11 1981 to install the system on a Bell 206 B helicopter (HL 9102) owned by Asia Aeroservice Company. The test survey was flown over an area including Hongseong, Daecheon, Seosan and Manripo Sheets, from Nov. 19 to Dec. 14 1981. A Hongseong air-strip was used as the base. (Author)

  10. Spectrally and Radiometrically Stable, Wideband, Onboard Calibration Source

    Coles, James B.; Richardson, Brandon S.; Eastwood, Michael L.; Sarture, Charles M.; Quetin, Gregory R.; Porter, Michael D.; Green, Robert O.; Nolte, Scott H.; Hernandez, Marco A.; Knoll, Linley A.

    2013-01-01

    The Onboard Calibration (OBC) source incorporates a medical/scientific-grade halogen source with a precisely designed fiber coupling system, and a fiber-based intensity-monitoring feedback loop that results in radiometric and spectral stabilities to within less than 0.3 percent over a 15-hour period. The airborne imaging spectrometer systems developed at the Jet Propulsion Laboratory incorporate OBC sources to provide auxiliary in-use system calibration data. The use of the OBC source will provide a significant increase in the quantitative accuracy, reliability, and resulting utility of the spectral data collected from current and future imaging spectrometer instruments.

  11. Measurement of atmospheric CO2 column concentrations to cloud tops with a pulsed multi-wavelength airborne lidar

    Mao, Jianping; Ramanathan, Anand; Abshire, James B.; Kawa, Stephan R.; Riris, Haris; Allan, Graham R.; Rodriguez, Michael; Hasselbrack, William E.; Sun, Xiaoli; Numata, Kenji; Chen, Jeff; Choi, Yonghoon; Yang, Mei Ying Melissa

    2018-01-01

    We have measured the column-averaged atmospheric CO2 mixing ratio to a variety of cloud tops by using an airborne pulsed multi-wavelength integrated-path differential absorption (IPDA) lidar. Airborne measurements were made at altitudes up to 13 km during the 2011, 2013 and 2014 NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) science campaigns flown in the United States West and Midwest and were compared to those from an in situ sensor. Analysis of the lidar backscatter profiles shows the average cloud top reflectance was ˜ 5 % for the CO2 measurement at 1572.335 nm except to cirrus clouds, which had lower reflectance. The energies for 1 µs wide laser pulses reflected from cloud tops were sufficient to allow clear identification of CO2 absorption line shape and then to allow retrievals of atmospheric column CO2 from the aircraft to cloud tops more than 90 % of the time. Retrievals from the CO2 measurements to cloud tops had minimal bias but larger standard deviations when compared to those made to the ground, depending on cloud top roughness and reflectance. The measurements show this new capability helps resolve CO2 horizontal and vertical gradients in the atmosphere. When used with nearby full-column measurements to ground, the CO2 measurements to cloud tops can be used to estimate the partial-column CO2 concentration below clouds, which should lead to better estimates of surface carbon sources and sinks. This additional capability of the range-resolved CO2 IPDA lidar technique provides a new benefit for studying the carbon cycle in future airborne and space-based CO2 missions.

  12. Measurement of Atmospheric CO2 Column Concentrations to Cloud Tops With a Pulsed Multi-Wavelength Airborne Lidar

    Mao, Jianping; Ramanathan, Anand; Abshire, James B.; Kawa, Stephan R.; Riris, Haris; Allan, Graham R.; Rodriguez, Michael R.; Hasselbrack, William E.; Sun, Xiaoli; Numata, Kenji; hide

    2018-01-01

    We have measured the column-averaged atmospheric CO2 mixing ratio to a variety of cloud tops by using an airborne pulsed multi-wavelength integrated-path differential absorption (IPDA) lidar. Airborne measurements were made at altitudes up to 13 km during the 2011, 2013 and 2014 NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) science campaigns flown in the United States West and Midwest and were compared to those from an in situ sensor. Analysis of the lidar backscatter profiles shows the average cloud top reflectance was approx. 5% for the CO2 measurement at 1572.335 nm except to cirrus clouds, which had lower reflectance. The energies for 1 micro-s wide laser pulses reflected from cloud tops were sufficient to allow clear identification of CO2 absorption line shape and then to allow retrievals of atmospheric column CO2 from the aircraft to cloud tops more than 90% of the time. Retrievals from the CO2 measurements to cloud tops had minimal bias but larger standard deviations when compared to those made to the ground, depending on cloud top roughness and reflectance. The measurements show this new capability helps resolve CO2 horizontal and vertical gradients in the atmosphere. When used with nearby full-column measurements to ground, the CO2 measurements to cloud tops can be used to estimate the partial-column CO2 concentration below clouds, which should lead to better estimates of surface carbon sources and sinks. This additional capability of the range-resolved CO2 IPDA lidar technique provides a new benefit for studying the carbon cycle in future airborne and space-based CO2 missions.

  13. Measurement of atmospheric CO2 column concentrations to cloud tops with a pulsed multi-wavelength airborne lidar

    J. Mao

    2018-01-01

    Full Text Available We have measured the column-averaged atmospheric CO2 mixing ratio to a variety of cloud tops by using an airborne pulsed multi-wavelength integrated-path differential absorption (IPDA lidar. Airborne measurements were made at altitudes up to 13 km during the 2011, 2013 and 2014 NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS science campaigns flown in the United States West and Midwest and were compared to those from an in situ sensor. Analysis of the lidar backscatter profiles shows the average cloud top reflectance was ∼ 5 % for the CO2 measurement at 1572.335 nm except to cirrus clouds, which had lower reflectance. The energies for 1 µs wide laser pulses reflected from cloud tops were sufficient to allow clear identification of CO2 absorption line shape and then to allow retrievals of atmospheric column CO2 from the aircraft to cloud tops more than 90 % of the time. Retrievals from the CO2 measurements to cloud tops had minimal bias but larger standard deviations when compared to those made to the ground, depending on cloud top roughness and reflectance. The measurements show this new capability helps resolve CO2 horizontal and vertical gradients in the atmosphere. When used with nearby full-column measurements to ground, the CO2 measurements to cloud tops can be used to estimate the partial-column CO2 concentration below clouds, which should lead to better estimates of surface carbon sources and sinks. This additional capability of the range-resolved CO2 IPDA lidar technique provides a new benefit for studying the carbon cycle in future airborne and space-based CO2 missions.

  14. Airborne Measurements of Atmospheric Pressure made Using an IPDA Lidar Operating in the Oxygen A-Band

    Riris, Haris; Abshire, James B.; Stephen, Mark; Rodriquez, Michael; Allan, Graham; Hasselbrack, William; Mao, Jianping

    2012-01-01

    We report airborne measurements of atmospheric pressure made using an integrated path differential absorption (IPDA) lidar that operates in the oxygen A-band near 765 nm. Remote measurements of atmospheric temperature and pressure are needed for NASA s Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission to measure atmospheric CO2. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve our predictions of climate change. The goal of ASCENDS is to determine the CO2 dry mixing ratio with lidar measurements from space at a level of 1 ppm. Analysis to date shows that with current weather models, measurements of both the CO2 column density and the column density of dry air are needed. Since O2 is a stable molecule that uniformly mixed in the atmosphere, measuring O2 absorption in the atmosphere can be used to infer the dry air density. We have developed an airborne (IPDA) lidar for Oxygen, with support from the NASA ESTO IIP program. Our lidar uses DFB-based seed laser diodes, a pulsed modulator, a fiber laser amplifier, and a non-linear crystal to generate wavelength tunable 765 nm laser pulses with a few uJ/pulse energy. The laser pulse rate is 10 KHz, and average transmitted laser power is 20 mW. Our lidar steps laser pulses across a selected line O2 doublet near 764.7 nm in the Oxygen A-band. The direct detection lidar receiver uses a 20 cm diameter telescope, a Si APD detector in Geiger mode, and a multi-channel scalar to detect and record the time resolved laser backscatter in 40 separate wavelength channels. Subsequent analysis is used to estimate the transmission line shape of the doublet for the laser pulses reflected from the ground. Ground based data analysis allows averaging from 1 to 60 seconds to increase SNR in the transmission line shape of the doublet. Our retrieval algorithm fits the expected O2 lineshapes against the measurements and

  15. Measuring Radiant Emissions from Entire Prescribed Fires with Ground, Airborne and Satellite Sensors RxCADRE 2012

    Dickinson, Matthew B.; Hudak, Andrew T.; Zajkowski, Thomas; Loudermilk, E. Louise; Schroeder, Wilfrid; Ellison, Luke; Kremens, Robert L.; Holley, William; Martinez, Otto; Paxton, Alexander; hide

    2015-01-01

    Characterising radiation from wildland fires is an important focus of fire science because radiation relates directly to the combustion process and can be measured across a wide range of spatial extents and resolutions. As part of a more comprehensive set of measurements collected during the 2012 Prescribed Fire Combustion and Atmospheric Dynamics Research (RxCADRE) field campaign, we used ground, airborne and spaceborne sensors to measure fire radiative power (FRP) from whole fires, applying different methods to small (2 ha) and large (.100 ha) burn blocks. For small blocks (n1/46), FRP estimated from an obliquely oriented long-wave infrared (LWIR) camera mounted on a boom lift were compared with FRP derived from combined data from tower-mounted radiometers and remotely piloted aircraft systems (RPAS). For large burn blocks (n1/43), satellite FRP measurements from the Moderate-resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) sensors were compared with near-coincident FRP measurements derived from a LWIR imaging system aboard a piloted aircraft. We describe measurements and consider their strengths and weaknesses. Until quantitative sensors exist for small RPAS, their use in fire research will remain limited. For oblique, airborne and satellite sensors, further FRP measurement development is needed along with greater replication of coincident measurements, which we show to be feasible.

  16. Radiometric determination in situ of the face grades in Witwatersrand gold and uranium mines

    Smit, C.J.B.

    1985-01-01

    A prototype collimated radiometric face scanner was tested in the Harmony Gold Mine. The results obtained during the pilot study indicate that in situ radiometric uranium assays are statistically indistinguishable from those obtained conventionally from channel chip samples. In addition, the study demonstrated that reasonably reliable gold estimates can be deduced from the radiometric measurements, by use of the ratio of gold to uranium within a mine. The instrumentation, calibration procedures, and background determination are described briefly

  17. Airborne measurement of submicron aerosol number concentration and CCN activity in and around the Korean Peninsula and their comparison to ground measurement in Seoul

    Park, M.; Kim, N.; Yum, S. S.

    2016-12-01

    Aerosols exert impact not only on human health and visibility but also on climate change directly by scattering or absorbing solar radiation and indirectly by acting as cloud condensation nuclei (CCN) and thus altering cloud radiative and microphysical properties. Aerosol indirect effects on climate has been known to have large uncertainty because of insufficient measurement data on aerosol and CCN activity distribution. Submicron aerosol number concentration (NCN, TSI CPC) and CCN number concentration (NCCN, DMT CCNC) were measured on board the NASA DC-8 research aircraft and at a ground site at Olympic Park in Seoul from May 2nd to June 10th, 2016. CCNC on the airborne platform was operated with the fixed internal supersaturation of 0.6% and CCNC at the ground site was operated with the five different supersaturations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). The NASA DC-8 conducted 20 research flights (about 150 hours) in and around the Korean Peninsula and the ground measurement at Olympic Park was continuously made during the measurement period. Both airborne and ground measurements showed spatially and temporally varied aerosol number concentration and CCN activity. Aerosol number concentration in the boundary layer measured on airborne platform was highly affected by pollution sources on the ground. The average diurnal distribution of ground aerosol number concentration showed distinct peaks are located at about 0800, 1500, and 2000. The middle peak indicates that new particle formation events frequently occurred during the measurement period. CCN activation ratio at 0.6% supersaturation (NCCN/NCN) of the airborne measurement ranged from 0.1 to 0.9, indicating that aerosol properties in and around the Korean Peninsula varied so much (e. g. size, hygroscopicity). Comprehensive analysis results will be shown at the conference.

  18. Quantification of Greenhouse Gas Emission Rates from strong Point Sources by Airborne IPDA-Lidar Measurements: Methodology and Experimental Results

    Ehret, G.; Amediek, A.; Wirth, M.; Fix, A.; Kiemle, C.; Quatrevalet, M.

    2016-12-01

    We report on a new method and on the first demonstration to quantify emission rates from strong greenhouse gas (GHG) point sources using airborne Integrated Path Differential Absorption (IPDA) Lidar measurements. In order to build trust in the self-reported emission rates by countries, verification against independent monitoring systems is a prerequisite to check the reported budget. A significant fraction of the total anthropogenic emission of CO2 and CH4 originates from localized strong point sources of large energy production sites or landfills. Both are not monitored with sufficiently accuracy by the current observation system. There is a debate whether airborne remote sensing could fill in the gap to infer those emission rates from budgeting or from Gaussian plume inversion approaches, whereby measurements of the GHG column abundance beneath the aircraft can be used to constrain inverse models. In contrast to passive sensors, the use of an active instrument like CHARM-F for such emission verification measurements is new. CHARM-F is a new airborne IPDA-Lidar devised for the German research aircraft HALO for the simultaneous measurement of the column-integrated dry-air mixing ratio of CO2 and CH4 commonly denoted as XCO2 und XCH4, respectively. It has successfully been tested in a serious of flights over Central Europe to assess its performance under various reflectivity conditions and in a strongly varying topography like the Alps. The analysis of a methane plume measured in crosswind direction of a coal mine ventilation shaft revealed an instantaneous emission rate of 9.9 ± 1.7 kt CH4 yr-1. We discuss the methodology of our point source estimation approach and give an outlook on the CoMet field experiment scheduled in 2017 for the measurement of anthropogenic and natural GHG emissions by a combination of active and passive remote sensing instruments on research aircraft.

  19. In situ airborne measurements of aerosol optical properties during photochemical pollution events

    Mallet, M.; van Dingenen, R.; Roger, J. C.; Despiau, S.; Cachier, H.

    2005-02-01

    Dry aerosol optical properties (scattering, absorbing coefficients, and single scattering albedo) were derived from in situ airborne measurements during two photochemical pollution events (25 and 26 June) observed during the Experience sur Site pour Contraindre les Modeles de Pollution atmospherique et de Transport d'Emissions (ESCOMPTE) experiment. Two flights were carried out during daytime (one during the morning and one at noon) over a domain, allowing the investigation of how an air pollution event affects the particle optical properties. Both horizontal distribution and vertical profiles are presented. Results from the horizontal mapping show that plumes of enhanced scattering and absorption are formed in the planetary boundary layer (PBL) during the day in the sea breeze-driven outflow of the coastal urban-industrial area of Marseille-Fos de Berre. The domain-averaged scattering coefficient (at 550 nm) over land σs changes from 35 (28) Mm-1 during land breeze to 63 (43) Mm-1 during sea breeze on 25 June (26 June), with local maxima reaching > 100 Mm-1. The increase in the scattering coefficient is associated with new particle formation, indicative of secondary aerosol formation. Simultaneously, the domain-averaged absorption coefficient increases from 5.6 (3.4) Mm-1 to 9.3 (8.0) Mm-1. The pollution plume leads to strong gradients in the single scattering albedo ωo over the domain studied, with local values as low as 0.73 observed inside the pollution plume. The role of photochemistry and secondary aerosol formation during the 25 June case is shown to increase ωo and to make the aerosol more `reflecting' while the plume moves away from the sources. The lower photochemical activity, observed in the 26 June case, induces a relatively higher contribution of black carbon, making the aerosol more absorbing. Results from vertical profiles at a single near-urban location in the domain indicate that the changes in optical properties happen almost entirely within

  20. Essential Climate Variables for the Ice Sheets from Space and Airborne measurements

    Fredenslund Levinsen, Joanna

    The Greenland Ice Sheet is the largest ice mass in the northern hemisphere.Over the past decade, it has undergone substantial changes in e.g. mass balance,surface velocity, and ice thickness. The latter is reflected by surfaceelevation changes, which are detectable with altimetry. Therefore......, this studyexploits the advantages of radar and laser altimetry to analyze surface elevationchanges and build a Digital Elevation Model of the ice sheet. Selected advantagesare radar data’s continuity in time and laser data’s higher horizontal andvertical accuracy. Therefore, ESA Envisat and CryoSat-2 radar altimetry...... dataare used in conjunction with laser data from NASA’s ICESat and airborneATM and LVIS instruments, and from ESA’s airborne CryoVEx campaign.The study is part of the ESA Ice Sheets CCI project. With the release ofREAPER data, one goal is to use the more than two decades of ESA radaraltimetry to develop...

  1. Lidar measurements of ozone and aerosol distributions during the 1992 airborne Arctic stratospheric expedition

    Browell, Edward V.; Butler, Carolyn F.; Fenn, Marta A.; Grant, William B.; Ismail, Syed; Carter, Arlen F.

    1994-01-01

    The NASA Langley airborne differential absorption lidar system was operated from the NASA Ames DC-8 aircraft during the 1992 Airborne Arctic Stratospheric Expedition to investigate the distribution of stratospheric aerosols and ozone (O3) across the Arctic vortex from January to March 1992. Aerosols from the Mt. Pinatubo eruption were found outside and inside the Arctic vortex with distinctly different scattering characteristics and spatial distributions in the two regions. The aerosol and O3 distributions clearly identified the edge of the vortex and provided additional information on vortex dynamics and transport processes. Few polar stratospheric clouds were observed during the AASE-2; however, those that were found had enhanced scattering and depolarization over the background Pinatubo aerosols. The distribution of aerosols inside the vortex exhibited relatively minor changes during the AASE-2. Ozone depletion inside the vortex as limited to less than or equal to 20 percent in the altitude region from 15-20 km.

  2. Airborne gamma-radiation snow water-equivalent and soil-moisture measurements and satellite areal extent of snow-cover measurements. A user's guide. Version 3.0

    Carroll, T.; Allen, M.

    1988-01-01

    The National Remote Sensing Hydrology Program is managed by the Office of Hydrology and consists of the Airborne Snow Survey Section and the Satellite Hydrology Section. The Airborne Snow Survey Section makes airborne snow water-equivalent and soil-moisture measurements over large areas of the country subject to a severe and chronic snowmelt flooding threat. The User's Guide is intended primarily to provide field hydrologists with some background on the technical and administrative aspects of the National Remote Sensing Hydrology Program. The guide summarizes the techniques and procedures used to make and distribute real-time, operational airborne snow water-equivalent measurements and satellite areal extent of snow-cover measurements made over large areas of the country. The current airborne and satellite databases are summarized, and procedures to access the real-time observations through both AFOS and through a commercial, electronic bulletin board system are given in the appendices

  3. A first attempt to derive soil erosion rates from 137Cs airborne gamma measurements in two Alpine valleys

    Arata, Laura; Meusburger, Katrin; Bucher, Benno; Mabit, Lionel; Alewell, Christine

    2016-04-01

    The application of fallout radionuclides (FRNs) as soil tracers is currently one of the most promising and effective approach for evaluating soil erosion magnitudes in mountainous grasslands. Conventional assessment or measurement methods are laborious and constrained by the topographic and climatic conditions of the Alps. The 137Cs (half-life = 30.2 years) is the most frequently used FRN to study soil redistribution. However the application of 137Cs in alpine grasslands is compromised by the high heterogeneity of the fallout due to the origin of 137Cs fallout in the Alps, which is linked to single rain events occurring just after the Chernobyl accident when most of the Alpine soils were still covered by snow. The aim of this study was to improve our understanding of the 137Cs distribution in two study areas in the Central Swiss Alps: the Ursern valley (Canton Uri), and the Piora valley (Canton Ticino). In June 2015, a helicopter equipped with a NaI gamma detector flew over the two study sites and screened the 137Cs activity of the top soil. The use of airborne gamma measurements is particularly efficient in case of higher 137Cs concentration in the soil. Due to their high altitude and high precipitation rates, the Swiss Alps are expected to be more contaminated by 137Cs fallout than other parts of Switzerland. The airborne gamma measurements have been related to several key parameters which characterize the areas, such as soil properties, slopes, expositions and land uses. The ground truthing of the airborne measurements (i.e. the 137Cs laboratory measurements of the soil samples collected at the same points) returned a good fit. The obtained results offer an overview of the 137Cs concentration in the study areas, which allowed us to identify suitable reference sites, and to analyse the relationship between the 137Cs distribution and the above cited parameters. The authors also derived a preliminary qualitative and a quantitative assessment of soil redistribution

  4. Aerosol Properties Derived from Airborne Sky Radiance and Direct Beam Measurements in Recent NASA and DoE Field Campaigns

    Redemann, J.; Flynn, C. J.; Shinozuka, Y.; Russell, P. B.; Kacenelenbogen, M.; Segal-Rosenheimer, M.; Livingston, J. M.; Schmid, B.; Dunagan, S. E.; Johnson, R. R.; hide

    2014-01-01

    The AERONET (AErosol RObotic NETwork) ground-based suite of sunphotometers provides measurements of spectral aerosol optical depth (AOD), precipitable water and spectral sky radiance, which can be inverted to retrieve aerosol microphysical properties that are critical to assessments of aerosol-climate interactions. Because of data quality criteria and sampling constraints, there are significant limitations to the temporal and spatial coverage of AERONET data and their representativeness for global aerosol conditions.The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument, jointly developed by NASA Ames and PNNL (Pacific Northwest National Laboratory) with NASA Goddard collaboration, combines airborne sun tracking and AERONET-like sky scanning with spectroscopic detection. Being an airborne instrument, 4STAR has the potential to fill gaps in the AERONET data set. The 4STAR instrument operated successfully in the SEAC4RS (Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) experiment in Aug./Sep. 2013 aboard the NASA DC-8 and in the DoE (Department of Energy)-sponsored TCAP (Two Column Aerosol Project, July 2012 & Feb. 2013) experiment aboard the DoE G-1 aircraft. 4STAR provided direct beam measurements of hyperspectral AOD, columnar trace gas retrievals (H2O, O3, NO2), and the first ever airborne hyperspectral sky radiance scans, which can be inverted to yield the same products as AERONET ground-based observations. In this presentation, we provide an overview of the new 4STAR capabilities, with an emphasis on 26 high-quality sky radiance measurements carried out by 4STAR in SEAC4RS. We compare collocated 4STAR and AERONET sky radiances, as well as their retrievals of aerosol microphysical properties for a subset of the available case studies. We summarize the particle property and air-mass characterization studies made possible by the combined 4STAR direct beam and sky radiance

  5. Investigating Ozone Sources in California Using AJAX Airborne Measurements and Models: Implications for Stratospheric Intrusion and Long Range Transport

    Ryoo, Ju-Mee; Johnson, Matthew S.; Iraci, Laura T.; Yates, Emma L.; Pierce, R. Bradley; Tanaka, Tomoaki; Gore, Warren

    2016-01-01

    High ozone concentrations at low altitudes near the surface were detected from airborne Alpha Jet Atmospheric eXperiment (AJAX) measurements on May 30, 2012. We investigate the causes of the elevated ozone concentrations using the airborne measurements and various models. GEOSchem and WRF-STILT model simulations show that the contribution from local sources is small. From MERRA reanalysis, it is found that high potential vorticity (PV) is observed at low altitudes. This high PV appears to be only partially coming through the stratospheric intrusions because the air inside the high PV region is moist, which shows that mixing appears to be enhanced in the low altitudes. Considering that diabatic heating can also produce high PV in the lower troposphere, high ozone is partially coming through stratospheric intrusion, but this cannot explain the whole ozone concentration in the target areas of the western U.S. A back-trajectory model is utilized to see where the air masses originated. The air masses of the target areas came from the lower stratosphere (LS), upper (UT), mid- (MT), and lower troposphere (LT). The relative number of trajectories coming from LS and UT is low (7.7% and 7.6%, respectively) compared to that from LT (64.1%), but the relative ozone concentration coming from LS and UT is high (38.4% and 20.95%, respectively) compared to that from LT (17.7%). The air mass coming from LT appears to be mostly coming from Asia. Q diagnostics show that there is sufficient mixing along the trajectory to indicate that ozone from the different origins is mixed and transported to the western U.S. This study shows that high ozone concentrations can be detected by airborne measurements, which can be analyzed by integrated platforms such as models, reanalysis, and satellite data.

  6. Investigation of Ozone Sources in California Using AJAX Airborne Measurements and Models: Implications for Stratospheric Intrusion and Long Range Transport

    Ryoo, Ju-Mee; Johnson, Matthew S.; Iraci, Laura T.; Yates, Emma L.; Pierce, R. Bradley; Tanaka, Tomoaki; Gore, Warren

    2015-01-01

    High ozone concentrations at low altitudes near the surface were detected from airborne Alpha Jet Atmospheric eXperiment (AJAX) measurements on May 30, 2012. We investigate the causes of the elevated ozone concentrations using the airborne measurements and various models. GEOS-chem and WRF-STILT model simulations show that the contribution from local sources is small. From MERRA reanalysis, it is found that high potential vorticity (PV) is observed at low altitudes. This high PV appears to be only partially coming through the stratospheric intrusions because the air inside the high PV region is moist, which shows that mixing appears to be enhanced in the low altitudes. Considering that diabatic heating can also produce high PV in the lower troposphere, high ozone is partially coming through stratospheric intrusion, but this cannot explain the whole ozone concentration in the target areas of the western U.S. A back-trajectory model is utilized to see where the air masses originated. The air masses of the target areas came from the lower stratosphere (LS), upper (UT), mid- (MT), and lower troposphere (LT). The relative number of trajectories coming from LS and UT is low (7.7 and 7.6, respectively) compared to that from LT (64.1), but the relative ozone concentration coming from LS and UT is high (38.4 and 20.95, respectively) compared to that from LT (17.7). The air mass coming from LT appears to be mostly coming from Asia. Q diagnostics show that there is sufficient mixing along the trajectory to indicate that ozone from the different origins is mixed and transported to the western U.S. This study shows that high ozone concentrations can be detected by airborne measurements, which can be analyzed by integrated platforms such as models, reanalysis, and satellite data.

  7. Application of Gauss's theorem to quantify localized surface emissions from airborne measurements of wind and trace gases

    Conley, Stephen; Faloona, Ian; Mehrotra, Shobhit; Suard, Maxime; Lenschow, Donald H.; Sweeney, Colm; Herndon, Scott; Schwietzke, Stefan; Pétron, Gabrielle; Pifer, Justin; Kort, Eric A.; Schnell, Russell

    2017-09-01

    Airborne estimates of greenhouse gas emissions are becoming more prevalent with the advent of rapid commercial development of trace gas instrumentation featuring increased measurement accuracy, precision, and frequency, and the swelling interest in the verification of current emission inventories. Multiple airborne studies have indicated that emission inventories may underestimate some hydrocarbon emission sources in US oil- and gas-producing basins. Consequently, a proper assessment of the accuracy of these airborne methods is crucial to interpreting the meaning of such discrepancies. We present a new method of sampling surface sources of any trace gas for which fast and precise measurements can be made and apply it to methane, ethane, and carbon dioxide on spatial scales of ˜ 1000 m, where consecutive loops are flown around a targeted source region at multiple altitudes. Using Reynolds decomposition for the scalar concentrations, along with Gauss's theorem, we show that the method accurately accounts for the smaller-scale turbulent dispersion of the local plume, which is often ignored in other average mass balance methods. With the help of large eddy simulations (LES) we further show how the circling radius can be optimized for the micrometeorological conditions encountered during any flight. Furthermore, by sampling controlled releases of methane and ethane on the ground we can ascertain that the accuracy of the method, in appropriate meteorological conditions, is often better than 10 %, with limits of detection below 5 kg h-1 for both methane and ethane. Because of the FAA-mandated minimum flight safe altitude of 150 m, placement of the aircraft is critical to preventing a large portion of the emission plume from flowing underneath the lowest aircraft sampling altitude, which is generally the leading source of uncertainty in these measurements. Finally, we show how the accuracy of the method is strongly dependent on the number of sampling loops and/or time

  8. Empirical Radiometric Normalization of Road Points from Terrestrial Mobile Lidar System

    Tee-Ann Teo

    2015-05-01

    Full Text Available Lidar data provide both geometric and radiometric information. Radiometric information is influenced by sensor and target factors and should be calibrated to obtain consistent energy responses. The radiometric correction of airborne lidar system (ALS converts the amplitude into a backscatter cross-section with physical meaning value by applying a model-driven approach. The radiometric correction of terrestrial mobile lidar system (MLS is a challenging task because it does not completely follow the inverse square range function at near-range. This study proposed a radiometric normalization workflow for MLS using a data-driven approach. The scope of this study is to normalize amplitude of road points for road surface classification, assuming that road points from different scanners or strips should have similar responses in overlapped areas. The normalization parameters for range effect were obtained from crossroads. The experiment showed that the amplitude difference between scanners and strips decreased after radiometric normalization and improved the accuracy of road surface classification.

  9. Itinerant radiometric laboratory (IRL-76)

    Dolgirev, E.I.; Domaratskij, V.P.; Kostikov, Yu.I.

    1978-01-01

    A mobile radiometric laboratory for routine radiation monitoring of the environment, personnel, and population is described. As compared to the previous models, this one incorporates a number of new features and is more informative and versatile. The design and main technical and operating characteristics of the laboratory are detailed

  10. Short-term Changes of Apparent Optical Properties in a Shallow Water Environment: Observations from Repeated Airborne Hyperspectral Measurements

    Zhang, M.; English, D. C.; Hu, C.; Carlson, P. R., Jr.; Muller-Karger, F. E.; Toro-Farmer, G.; Herwitz, S. R.

    2016-02-01

    An atmospheric correction algorithm has been developed for AISA imagery over optically shallow waters in Sugarloaf Key of the Florida Keys. The AISA data were collected repeatedly during several days in May 2012, October 2012, and May 2013. A non-zero near-infrared (NIR) remote sensing reflectance (Rrs) was accounted for through iterations, based on the relationship of field-measured Rrs between the NIR and red wavelengths. Validation showed mean ratios of 0.94 to 1.002 between AISA-derived and field-measured Rrs in the blue to red wavelengths, with uncertainties generally turbidity (light attenuation) and bottom contributions. Some of these changes are larger than two times of the Rrs uncertainties from the AISA retrievals, therefore representing statistically significant changes that can be well observed from airborne measurements. The case study suggests that repeated airborne measurements may be used to study short-term changes in shallow water environments, and such a capacity may be enhanced with future geostationary satellite missions specifically designed to observe coastal ecosystems.

  11. Potential of remote sensing of cirrus optical thickness by airborne spectral radiance measurements at different sideward viewing angles

    Wolf, Kevin; Ehrlich, André; Hüneke, Tilman; Pfeilsticker, Klaus; Werner, Frank; Wirth, Martin; Wendisch, Manfred

    2017-03-01

    Spectral radiance measurements collected in nadir and sideward viewing directions by two airborne passive solar remote sensing instruments, the Spectral Modular Airborne Radiation measurement sysTem (SMART) and the Differential Optical Absorption Spectrometer (mini-DOAS), are used to compare the remote sensing results of cirrus optical thickness τ. The comparison is based on a sensitivity study using radiative transfer simulations (RTS) and on data obtained during three airborne field campaigns: the North Atlantic Rainfall VALidation (NARVAL) mission, the Mid-Latitude Cirrus Experiment (ML-CIRRUS) and the Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems (ACRIDICON) campaign. Radiative transfer simulations are used to quantify the sensitivity of measured upward radiance I with respect to τ, ice crystal effective radius reff, viewing angle of the sensor θV, spectral surface albedo α, and ice crystal shape. From the calculations it is concluded that sideward viewing measurements are generally better suited than radiance data from the nadir direction to retrieve τ of optically thin cirrus, especially at wavelengths larger than λ = 900 nm. Using sideward instead of nadir-directed spectral radiance measurements significantly improves the sensitivity and accuracy in retrieving τ, in particular for optically thin cirrus of τ ≤ 2. The comparison of retrievals of τ based on nadir and sideward viewing radiance measurements from SMART, mini-DOAS and independent estimates of τ from an additional active remote sensing instrument, the Water Vapor Lidar Experiment in Space (WALES), shows general agreement within the range of measurement uncertainties. For the selected example a mean τ of 0.54 ± 0.2 is derived from SMART, and 0.49 ± 0.2 by mini-DOAS nadir channels, while WALES obtained a mean value of τ = 0.32 ± 0.02 at 532 nm wavelength, respectively. The mean of τ derived from the sideward viewing mini

  12. A COMPARISON OF LIDAR REFLECTANCE AND RADIOMETRICALLY CALIBRATED HYPERSPECTRAL IMAGERY

    A. Roncat

    2016-06-01

    Full Text Available In order to retrieve results comparable under different flight parameters and among different flight campaigns, passive remote sensing data such as hyperspectral imagery need to undergo a radiometric calibration. While this calibration, aiming at the derivation of physically meaningful surface attributes such as a reflectance value, is quite cumbersome for passively sensed data and relies on a number of external parameters, the situation is by far less complicated for active remote sensing techniques such as lidar. This fact motivates the investigation of the suitability of full-waveform lidar as a “single-wavelength reflectometer” to support radiometric calibration of hyperspectral imagery. In this paper, this suitability was investigated by means of an airborne hyperspectral imagery campaign and an airborne lidar campaign recorded over the same area. Criteria are given to assess diffuse reflectance behaviour; the distribution of reflectance derived by the two techniques were found comparable in four test areas where these criteria were met. This is a promising result especially in the context of current developments of multi-spectral lidar systems.

  13. Airborne measurements of reactive organic trace gases in the atmosphere - with a focus on PTR-MS measurements onboard NASA's flying laboratories

    Wisthaler, Armin; Mikoviny, Tomas; Müller, Markus; Schiller, Sven Arne; Feil, Stefan; Hanel, Gernot; Jordan, Alfons; Mutschlechner, Paul; Crawford, James H.; Singh, Hanwant B.; Millet, Dylan

    2017-04-01

    Reactive organic gases (ROGs) play an important role in atmospheric chemistry as they affect the rates of ozone production, particle formation and growth, and oxidant consumption. Measurements of ROGs are analytically challenging because of their large variety and low concentrations in the Earth's atmosphere, and because they are easily affected by measurement artefacts. On aircraft, ROGs are typically measured by canister sampling followed by off-line analysis in the laboratory, fast online gas chromatography or online chemical ionization mass spectrometry. In this work, we will briefly sum up the state-of-the-art in this field before focusing on proton-transfer-reaction mass spectrometry (PTR-MS) and its deployment onboard NASA's airborne science laboratories. We will show how airborne PTR-MS was successfully used in NASA missions for characterizing emissions of ROGs from point sources, for following the photochemical evolution of ROGs in a biomass burning plume, for determining biosphere-atmosphere fluxes of selected ROGs and for validating satellite data. We will also present the airborne PTR-MS instrument in its most recent evolution which includes a radiofrequency ion funnel and ion guide combined with a compact time-of-flight mass spectrometer and discuss its superior performance characteristics. The development of the airborne PTR-MS instrument was supported by the Austrian Federal Ministry for Transport, Innovation and Technology (bmvit) through the Austrian Space Applications Programme (ASAP) of the Austrian Research Promotion Agency (FFG) (grants #833451, #847967). This work was also partly supported by NASA under grant #NNX14AP89G.

  14. Airborne measurements of CO2, CH4 and HCN in boreal biomass burning plumes

    O'Shea, Sebastian J.; Bauguitte, Stephane; Muller, Jennifer B. A.; Le Breton, Michael; Archibald, Alex; Gallagher, Martin W.; Allen, Grant; Percival, Carl J.

    2013-04-01

    Biomass burning plays an important role in the budgets of a variety of atmospheric trace gases and particles. For example, fires in boreal Russia have been linked with large growths in the global concentrations of trace gases such as CO2, CH4 and CO (Langenfelds et al., 2002; Simpson et al., 2006). High resolution airborne measurements of CO2, CH4 and HCN were made over Eastern Canada onboard the UK Atmospheric Research Aircraft FAAM BAe-146 from 12 July to 4 August 2011. These observations were made as part of the BORTAS project (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites). Flights were aimed at transecting and sampling the outflow from the commonly occurring North American boreal forest fires during the summer months and to investigate and identify the chemical composition and evolution of these plumes. CO2 and CH4 dry air mole fractions were determined using an adapted system based on a Fast Greenhouse Gas Analyser (FGGA, Model RMT-200) from Los Gatos Research Inc, which uses the cavity enhanced absorption spectroscopy technique. In-flight calibrations revealed a mean accuracy of 0.57 ppmv and 2.31 ppbv for 1 Hz observations of CO2 and CH4, respectively, during the BORTAS project. During these flights a number of fresh and photochemically-aged plumes were identified using simultaneous HCN measurements. HCN is a distinctive and useful marker for forest fire emissions and it was detected using chemical ionisation mass spectrometry (CIMS). In the freshest plumes, strong relationships were found between CH4, CO2 and other tracers for biomass burning. From this we were able to estimate that 8.5 ± 0.9 g of CH4 and 1512 ± 185 g of CO2 were released into the atmosphere per kg of dry matter burnt. These emission factors are in good agreement with estimates from previous studies and can be used to calculate budgets for the region. However for aged plumes the correlations between CH4 and other

  15. A compact PTR-ToF-MS instrument for airborne measurements of volatile organic compounds at high spatiotemporal resolution

    M. Müller

    2014-11-01

    Full Text Available Herein, we report on the development of a compact proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS for airborne measurements of volatile organic compounds (VOCs. The new instrument resolves isobaric ions with a mass resolving power (m/Δm of ~1000, provides accurate m/z measurements (Δm < 3 mDa, records full mass spectra at 1 Hz and thus overcomes some of the major analytical deficiencies of quadrupole-MS-based airborne instruments. 1 Hz detection limits for biogenic VOCs (isoprene, α total monoterpenes, aromatic VOCs (benzene, toluene, xylenes and ketones (acetone, methyl ethyl ketone range from 0.05 to 0.12 ppbV, making the instrument well-suited for fast measurements of abundant VOCs in the continental boundary layer. The instrument detects and quantifies VOCs in locally confined plumes (< 1 km, which improves our capability of characterizing emission sources and atmospheric processing within plumes. A deployment during the NASA 2013 DISCOVER-AQ mission generated high vertical- and horizontal-resolution in situ data of VOCs and ammonia for the validation of satellite retrievals and chemistry transport models.

  16. Results of dust precipitation and airborne dust measurements in the Rhineland Brown Coal Mining Area in 1991 and 1992

    Respondek, A.; Stein, W.

    1994-01-01

    In the Rhineland brown coal mining area the immission value of IW 1 = 0.35 g/(m 2 xd), as stipulated in the Technical Specifications for Air Pollution Control, was not reached anywhere in the entire above-mentioned measured area in 1991. The maximum monthly pollution load, i.e. I 2 = 0.52 g/(m 2 xd), was less than the immission value IW 2 = 0.65 g/(m 2 xd). In the measured areas under review, Rheinschiene South and Rheinschiene Centre, the values for airborne dust immission I 1 in 1991 were also less than 50% of the IW 1 value of 0.15 mg/m 3 . In view of these results and also - the measurements carried out by the LIS (State Pollution Control Authority) over many years in the townships of Kerpen, Frechen-Bachem, Huerth-Hermuelheim, Horrem, Frechen and Pulheim. - A special measurement carried out by the LIS in the Erft district and in the south of the Neuss district in 1983, and - the measurements carried out in accordance with the specifications for the licensing and development plan procedures, as well as - the results of the special measurement programme carried out in the community of Elsdorf in 1988 and 1989, there is no reason to fear that harmful effects on the environment will be caused by brown coal opencast mines and coal processing plants as a result of airborne dust. The dust precipitation measurements carried out at the request of the Cologne Mines Inspectorate revealed that in 1992 none of the values measured exceeded the IW 1 value. The highest measured I 1 value was 0.21 g/(m 2 xd), i.e. 60% of the IW 1 value. The average pollution load was 0.13 g/(m 2 xd), i.e. 37%. (orig./MSK) [de

  17. Spectrally and Radiometrically Stable Wide-Band on Board Calibration Source for In-Flight Data Validation in Imaging Spectroscopy Applications

    Coles, J. B.; Richardson, Brandon S.; Eastwood, Michael L.; Sarture, Charles M.; Quetin, Gregory R.; Hernandez, Marco A.; Kroll, Linley A.; Nolte, Scott H.; Porter, Michael D.; Green, Robert O.

    2011-01-01

    The quality of the quantitative spectral data collected by an imaging spectrometer instrument is critically dependent upon the accuracy of the spectral and radiometric calibration of the system. In order for the collected spectra to be scientifically useful, the calibration of the instrument must be precisely known not only prior to but during data collection. Thus, in addition to a rigorous in-lab calibration procedure, the airborne instruments designed and built by the NASA/JPL Imaging Spectroscopy Group incorporate an on board calibrator (OBC) system with the instrument to provide auxiliary in-use system calibration data. The output of the OBC source illuminates a target panel on the backside of the foreoptics shutter both before and after data collection. The OBC and in-lab calibration data sets are then used to validate and post-process the collected spectral image data. The resulting accuracy of the spectrometer output data is therefore integrally dependent upon the stability of the OBC source. In this paper we describe the design and application of the latest iteration of this novel device developed at NASA/JPL which integrates a halogen-cycle source with a precisely designed fiber coupling system and a fiber-based intensity monitoring feedback loop. The OBC source in this Airborne Testbed Spectrometer was run over a period of 15 hours while both the radiometric and spectral stabilities of the output were measured and demonstrated stability to within 1% of nominal.

  18. Radiometric mass flow probes for belt weighers - the state of the art and possibilities of application

    Glaeser, M.

    1986-01-01

    The setup of radiometric belt weighers is described in principle and compared with conventional ones. Fields of application are mentioned and a list is given of equipment comercially available. The comparison shows that the radiometric systems are advantageous in general, but in special cases (measuring error lower than 1%, chemical composition varies several 10%) gravimetric systems are indispensable

  19. Cigarettes vs. e-cigarettes: Passive exposure at home measured by means of airborne marker and biomarkers

    Ballbè, Montse [Tobacco Control Unit, Cancer Prevention and Control Program, Institut Català d' Oncologia, L’Hospitalet de Llobregat, Barcelona (Spain); Catalan Network of Smoke-free Hospitals, L' Hospitalet de Llobregat, Barcelona (Spain); Cancer Prevention and Control Group, Institut d' Investigació Biomèdica de Bellvitge – IDIBELL, L’Hospitalet de Llobregat, Barcelona (Spain); Addictions Unit, Institute of Neurosciences, Hospital Clínic de Barcelona – IDIBAPS, Barcelona (Spain); Department of Clinical Sciences, Universitat de Barcelona, Barcelona (Spain); Martínez-Sánchez, Jose M., E-mail: jmmartinez@iconcologia.net [Tobacco Control Unit, Cancer Prevention and Control Program, Institut Català d' Oncologia, L’Hospitalet de Llobregat, Barcelona (Spain); Cancer Prevention and Control Group, Institut d' Investigació Biomèdica de Bellvitge – IDIBELL, L’Hospitalet de Llobregat, Barcelona (Spain); Biostatistics Unit, Department of Basic Sciences, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Barcelona (Spain); Sureda, Xisca; Fu, Marcela [Tobacco Control Unit, Cancer Prevention and Control Program, Institut Català d' Oncologia, L’Hospitalet de Llobregat, Barcelona (Spain); Cancer Prevention and Control Group, Institut d' Investigació Biomèdica de Bellvitge – IDIBELL, L’Hospitalet de Llobregat, Barcelona (Spain); Department of Clinical Sciences, Universitat de Barcelona, Barcelona (Spain); and others

    2014-11-15

    Background: There is scarce evidence about passive exposure to the vapour released or exhaled from electronic cigarettes (e-cigarettes) under real conditions. The aim of this study is to characterise passive exposure to nicotine from e-cigarettes' vapour and conventional cigarettes' smoke at home among non-smokers under real-use conditions. Methods: We conducted an observational study with 54 non-smoker volunteers from different homes: 25 living at home with conventional smokers, 5 living with nicotine e-cigarette users, and 24 from control homes (not using conventional cigarettes neither e-cigarettes). We measured airborne nicotine at home and biomarkers (cotinine in saliva and urine). We calculated geometric mean (GM) and geometric standard deviations (GSD). We also performed ANOVA and Student's t tests for the log-transformed data. We used Bonferroni-corrected t-tests to control the family error rate for multiple comparisons at 5%. Results: The GMs of airborne nicotine were 0.74 μg/m{sup 3} (GSD=4.05) in the smokers’ homes, 0.13 μg/m{sup 3} (GSD=2.4) in the e-cigarettes users’ homes, and 0.02 μg/m{sup 3} (GSD=3.51) in the control homes. The GMs of salivary cotinine were 0.38 ng/ml (GSD=2.34) in the smokers’ homes, 0.19 ng/ml (GSD=2.17) in the e-cigarettes users’ homes, and 0.07 ng/ml (GSD=1.79) in the control homes. Salivary cotinine concentrations of the non-smokers exposed to e-cigarette's vapour at home (all exposed ≥2 h/day) were statistically significant different that those found in non-smokers exposed to second-hand smoke ≥2 h/day and in non-smokers from control homes. Conclusions: The airborne markers were statistically higher in conventional cigarette homes than in e-cigarettes homes (5.7 times higher). However, concentrations of both biomarkers among non-smokers exposed to conventional cigarettes and e-cigarettes’ vapour were statistically similar (only 2 and 1.4 times higher, respectively). The levels of airborne

  20. Cigarettes vs. e-cigarettes: Passive exposure at home measured by means of airborne marker and biomarkers

    Ballbè, Montse; Martínez-Sánchez, Jose M.; Sureda, Xisca; Fu, Marcela

    2014-01-01

    Background: There is scarce evidence about passive exposure to the vapour released or exhaled from electronic cigarettes (e-cigarettes) under real conditions. The aim of this study is to characterise passive exposure to nicotine from e-cigarettes' vapour and conventional cigarettes' smoke at home among non-smokers under real-use conditions. Methods: We conducted an observational study with 54 non-smoker volunteers from different homes: 25 living at home with conventional smokers, 5 living with nicotine e-cigarette users, and 24 from control homes (not using conventional cigarettes neither e-cigarettes). We measured airborne nicotine at home and biomarkers (cotinine in saliva and urine). We calculated geometric mean (GM) and geometric standard deviations (GSD). We also performed ANOVA and Student's t tests for the log-transformed data. We used Bonferroni-corrected t-tests to control the family error rate for multiple comparisons at 5%. Results: The GMs of airborne nicotine were 0.74 μg/m 3 (GSD=4.05) in the smokers’ homes, 0.13 μg/m 3 (GSD=2.4) in the e-cigarettes users’ homes, and 0.02 μg/m 3 (GSD=3.51) in the control homes. The GMs of salivary cotinine were 0.38 ng/ml (GSD=2.34) in the smokers’ homes, 0.19 ng/ml (GSD=2.17) in the e-cigarettes users’ homes, and 0.07 ng/ml (GSD=1.79) in the control homes. Salivary cotinine concentrations of the non-smokers exposed to e-cigarette's vapour at home (all exposed ≥2 h/day) were statistically significant different that those found in non-smokers exposed to second-hand smoke ≥2 h/day and in non-smokers from control homes. Conclusions: The airborne markers were statistically higher in conventional cigarette homes than in e-cigarettes homes (5.7 times higher). However, concentrations of both biomarkers among non-smokers exposed to conventional cigarettes and e-cigarettes’ vapour were statistically similar (only 2 and 1.4 times higher, respectively). The levels of airborne nicotine and

  1. Reliability and validity of expert assessment based on airborne and urinary measures of nickel and chromium exposure in the electroplating industry

    Chen, Yu-Cheng; Coble, Joseph B; Deziel, Nicole C.; Ji, Bu-Tian; Xue, Shouzheng; Lu, Wei; Stewart, Patricia A; Friesen, Melissa C

    2014-01-01

    The reliability and validity of six experts’ exposure ratings were evaluated for 64 nickel-exposed and 72 chromium-exposed workers from six Shanghai electroplating plants based on airborne and urinary nickel and chromium measurements. Three industrial hygienists and three occupational physicians independently ranked the exposure intensity of each metal on an ordinal scale (1–4) for each worker's job in two rounds: the first round was based on responses to an occupational history questionnaire and the second round also included responses to an electroplating industry-specific questionnaire. Spearman correlation (rs) was used to compare each rating's validity to its corresponding subject-specific arithmetic mean of four airborne or four urinary measurements. Reliability was moderately-high (weighted kappa range=0.60–0.64). Validity was poor to moderate (rs= -0.37–0.46) for both airborne and urinary concentrations of both metals. For airborne nickel concentrations, validity differed by plant. For dichotomized metrics, sensitivity and specificity were higher based on urinary measurements (47–78%) than airborne measurements (16–50%). Few patterns were observed by metal, assessment round, or expert type. These results suggest that, for electroplating exposures, experts can achieve moderately-high agreement and (reasonably) distinguish between low and high exposures when reviewing responses to in-depth questionnaires used in population-based case-control studies. PMID:24736099

  2. Reliability and validity of expert assessment based on airborne and urinary measures of nickel and chromium exposure in the electroplating industry.

    Chen, Yu-Cheng; Coble, Joseph B; Deziel, Nicole C; Ji, Bu-Tian; Xue, Shouzheng; Lu, Wei; Stewart, Patricia A; Friesen, Melissa C

    2014-11-01

    The reliability and validity of six experts' exposure ratings were evaluated for 64 nickel-exposed and 72 chromium-exposed workers from six Shanghai electroplating plants based on airborne and urinary nickel and chromium measurements. Three industrial hygienists and three occupational physicians independently ranked the exposure intensity of each metal on an ordinal scale (1-4) for each worker's job in two rounds: the first round was based on responses to an occupational history questionnaire and the second round also included responses to an electroplating industry-specific questionnaire. The Spearman correlation (r(s)) was used to compare each rating's validity to its corresponding subject-specific arithmetic mean of four airborne or four urinary measurements. Reliability was moderately high (weighted kappa range=0.60-0.64). Validity was poor to moderate (r(s)=-0.37-0.46) for both airborne and urinary concentrations of both metals. For airborne nickel concentrations, validity differed by plant. For dichotomized metrics, sensitivity and specificity were higher based on urinary measurements (47-78%) than airborne measurements (16-50%). Few patterns were observed by metal, assessment round, or expert type. These results suggest that, for electroplating exposures, experts can achieve moderately high agreement and (reasonably) distinguish between low and high exposures when reviewing responses to in-depth questionnaires used in population-based case-control studies.

  3. ARM Airborne Carbon Measurements (ARM-ACME) and ARM-ACME 2.5 Final Campaign Reports

    Biraud, S. C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tom, M. S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sweeney, C. [NOAA Earth Systems Research Lab., Boulder, CO (United States)

    2016-01-01

    We report on a 5-year multi-institution and multi-agency airborne study of atmospheric composition and carbon cycling at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, with scientific objectives that are central to the carbon-cycle and radiative-forcing goals of the U.S. Global Change Research Program and the North American Carbon Program (NACP). The goal of these measurements is to improve understanding of 1) the carbon exchange of the Atmospheric Radiation Measurement (ARM) SGP region; 2) how CO2 and associated water and energy fluxes influence radiative-forcing, convective processes, and CO2 concentrations over the ARM SGP region, and 3) how greenhouse gases are transported on continental scales.

  4. NASA COAST and OCEANIA Airborne Missions Support Ecosystem and Water Quality Research in the Coastal Zone

    Guild, Liane; Kudela, Raphael; Hooker, Stanford; Morrow, John; Russell, Philip; Palacios, Sherry; Livingston, John M.; Negrey, Kendra; Torres-Perez, Juan; Broughton, Jennifer

    2014-01-01

    NASA has a continuing requirement to collect high-quality in situ data for the vicarious calibration of current and next generation ocean color satellite sensors and to validate the algorithms that use the remotely sensed observations. Recent NASA airborne missions over Monterey Bay, CA, have demonstrated novel above- and in-water measurement capabilities supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The results characterize coastal atmospheric and aquatic properties through an end-to-end assessment of image acquisition, atmospheric correction, algorithm application, plus sea-truth observations from state-of-the-art instrument systems. The primary goal is to demonstrate the following in support of calibration and validation exercises for satellite coastal ocean color products: 1) the utility of a multi-sensor airborne instrument suite to assess the bio-optical properties of coastal California, including water quality; and 2) the importance of contemporaneous atmospheric measurements to improve atmospheric correction in the coastal zone. The imaging spectrometer (Headwall) is optimized in the blue spectral domain to emphasize remote sensing of marine and freshwater ecosystems. The novel airborne instrument, Coastal Airborne In-situ Radiometers (C-AIR) provides measurements of apparent optical properties with high dynamic range and fidelity for deriving exact water leaving radiances at the land-ocean boundary, including radiometrically shallow aquatic ecosystems. Simultaneous measurements supporting empirical atmospheric correction of image data are accomplished using the Ames Airborne Tracking Sunphotometer (AATS-14). Flight operations are presented for the instrument payloads using the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter flown over Monterey Bay during the seasonal fall algal bloom in 2011 (COAST) and 2013 (OCEANIA) to support bio-optical measurements of

  5. Airborne measurements over the boreal forest of southern Finland during new particle formation events in 2009 and 2010

    Schobesberger, S.; Vaananen, R.; Leino, K. [Helsinki Univ. (Finland). Dept. of Physics, Division of Atmospheric Sciences] [and others

    2013-06-01

    We conducted airborne observations of aerosol physical properties over the southern Finland boreal forest environment. The aim was to investigate the lower tropospheric aerosol (up to 4-km altitude) over an area of 250 by 200 km, in particular during new particle formation (NPF) events, and to address the spatial variability of aerosol number concentration and number size distribution. The regional NPF events, detected both airborne and at the ground, with air masses originating from the Arctic or northern Atlantic Ocean were studied throughout the boundary layer and throughout the area covered. Three suitable case studies are presented in more detail. In two of these studies, the concentrations of nucleation mode particles (3-10 nm in diameter) were found considerably higher (up to a factor of 30) in the upper parts of the planetary boundary layer compared to ground-based measurements during the nucleation events. The observed vertical variation can be connected to boundary layer dynamics and interactions between the boundary layer and the lower free troposphere, likely yielding high concentrations of newly formed aerosol particles. Our results suggest that nucleation does not necessarily occur close to the surface. In one presented case we found evidence of NPF occurring in a limited area above cloud, in the complete absence of a regional NPF event. (orig.)

  6. Validating MODIS Above-Cloud Aerosol Optical Depth Retrieved from Color Ratio Algorithm Using Direct Measurements Made by NASA's Airborne AATS and 4STAR Sensors

    Jethva, Hiren; Torres, Omar; Remer, Lorraine; Redemann, Jens; Livingston, John; Dunagan, Stephen; Shinozuka, Yohei; Kacenelenbogen, Meloe; Segal Rozenhaimer, Michal; Spurr, Rob

    2016-01-01

    We present the validation analysis of above-cloud aerosol optical depth (ACAOD) retrieved from the color ratio method applied to MODIS cloudy-sky reflectance measurements using the limited direct measurements made by NASAs airborne Ames Airborne Tracking Sunphotometer (AATS) and Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) sensors. A thorough search of the airborne database collection revealed a total of five significant events in which an airborne sun photometer, coincident with the MODIS overpass, observed partially absorbing aerosols emitted from agricultural biomass burning, dust, and wildfires over a low-level cloud deck during SAFARI-2000, ACE-ASIA 2001, and SEAC4RS 2013 campaigns, respectively. The co-located satellite-airborne match ups revealed a good agreement (root-mean-square difference less than 0.1), with most match ups falling within the estimated uncertainties associated with the MODIS retrievals (about -10 to +50 ). The co-retrieved cloud optical depth was comparable to that of the MODIS operational cloud product for ACE-ASIA and SEAC4RS, however, higher by 30-50% for the SAFARI-2000 case study. The reason for this discrepancy could be attributed to the distinct aerosol optical properties encountered during respective campaigns. A brief discussion on the sources of uncertainty in the satellite-based ACAOD retrieval and co-location procedure is presented. Field experiments dedicated to making direct measurements of aerosols above cloud are needed for the extensive validation of satellite based retrievals.

  7. Analyzing Source Apportioned Methane in Northern California During DISCOVER-AQ-CA Using Airborne Measurements and Model Simulations

    Johnson, Matthew S.

    2014-01-01

    This study analyzes source apportioned methane (CH4) emissions and atmospheric concentrations in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were 5.30 Gg/day (Gg 1.0 109 grams) (equating to 1.9 103 Gg/yr) for all of California. According to EDGAR, the SFBA and northern SJV region contributes 30 of total emissions from California. Source apportionment analysis during this study shows that CH4 concentrations over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 concentrations in northern California (average normalized mean bias (NMB) -5 and linear regression slope 0.25). The largest negative biases in the model were calculated on days when hot spots of local emission sources were measured and atmospheric CH4 concentrations reached values 3.0 parts per million (model NMB -10). Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California and further the understanding of the physical processes

  8. First Airborne IPDA Lidar Measurements of Methane and Carbon Dioxide Applying the DLR Greenhouse Gas Sounder CHARM-F

    Amediek, A.; Ehret, G.; Fix, A.; Wirth, M.; Quatrevalet, M.; Büdenbender, C.; Kiemle, C.; Loehring, J.; Gerbig, C.

    2015-12-01

    First airborne measurement using CHARM-F, the four-wavelengths lidar for simultaneous soundings of atmospheric CO2 and CH4, were performed in Spring 2015 onboard the German research aircraft HALO. The lidar is designed in the IPDA (integrated path differential absorption) configuration using short double pulses, which gives column averaged gas mixing ratios between aircraft and ground. HALO's maximum flight altitude of 15 km and special features of the lidar, such as a relatively large laser ground spot, enable the CHARM-F system to be an airborne demonstrator for future spaceborne greenhouse gas lidars. Due to a high technological conformity this applies in particular to the French-German satellite mission MERLIN, the spaceborne methane IPDA lidar. The successfully completed flight measurements provide a valuable dataset, which supports the retrieval algorithm development for MERLIN notably. The flights covered different ground cover types, different orography types as well as the sea. Additionally, we captured different cloud conditions, at which the broken cloud case is a matter of particular interest. This dataset allows detailed analyses of measurement sensitivities, general studies on the IPDA principle and on technical details of the system. These activities are supported by another instrument onboard: a cavity ring down spectrometer, providing in-situ data of carbon dioxide, methane and water vapor with high accuracy and precision, which is ideal for validation purposes of the lidar. Additionally the onboard instrumentation of HALO gives information about pressure and temperature for cross-checking the ECMWF data, which are intended to be used for calculating the weighting function, the key quantity for the retrieval of gas column mixing ratios from the measured gas optical depths. In combination with dedicated descents into the boundary layer and subsequent ascents, a self-contained dataset for characterizations of CHARM-F is available.

  9. Analyzing source apportioned methane in northern California during Discover-AQ-CA using airborne measurements and model simulations

    Johnson, Matthew S.; Yates, Emma L.; Iraci, Laura T.; Loewenstein, Max; Tadić, Jovan M.; Wecht, Kevin J.; Jeong, Seongeun; Fischer, Marc L.

    2014-12-01

    This study analyzes source apportioned methane (CH4) emissions and atmospheric mixing ratios in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were ∼5.30 Gg day-1 (Gg = 1.0 × 109 g) (equating to ∼1.90 × 103 Gg yr-1) for all of California. According to EDGAR, the SFBA and northern SJV region contributes ∼30% of total CH4 emissions from California. Source apportionment analysis during this study shows that CH4 mixing ratios over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 mixing ratios in northern California (average normalized mean bias (NMB) = -5.2% and linear regression slope = 0.20). The largest negative biases in the model were calculated on days when large amounts of CH4 were measured over local emission sources and atmospheric CH4 mixing ratios reached values >2.5 parts per million. Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California.

  10. PV radiometrics workshop proceedings

    Myers, D.R.

    1995-09-01

    This report documents presentations and discussions held at the Photovoltaics Radiometeric Measurements Workshop conducted at Vail, Colorado, on July 24 and 25, 1995. The workshop was sponsored and financed by the Photovoltaic Module and Systems Performance and Engineering Project managed by Richard DeBlasio, Principal Investigator. That project is a component of the National Renewable Energy Laboratory (NREL) Photovoltaic Research and Development Program, conducted by NREL for the US Department of Energy, through the NREL Photovoltaic Engineering and Applications Branch, managed by Roland Hulstrom. Separate abstracts have been prepared for articles from this workshop.

  11. Radiometric weighing devices. Part 1 and 2

    Glaeser, M.

    1985-01-01

    Proceeding from the physical and mathematical fundamentals and from the types of radiometric weighing devices presently available, the radiation protection problems arising from the application of radiometric gages in industry and agriculture are discussed. Nuclear weighing devices have been found to be effective from economic point of view but in some cases gravimetric conveyor weighers are indispensable. Information and guidance is given especially for users of radiometric weighing devices. 91 refs., 69 figs., and 8 tabs

  12. Development of an Airborne Triple-Pulse 2-Micron Integrated Path Differential Absorption Lidar (IPDA) for Simultaneous Airborne Column Measurements of Carbon Dioxide and Water Vapor in the Atmosphere

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong; Antill, Charles W.; Remus, Ruben

    2016-01-01

    This presentation will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar being developed at NASA Langley Research Center with support from NASA ESTO Instrument Incubator Program. The development of this active optical remote sensing IPDA instrument is targeted for measuring both atmospheric carbon dioxide and water vapor in the atmosphere from an airborne platform. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver and detector upgrades, laser packaging and lidar integration. Future plan for IPDA lidar system for ground integration, testing and flight validation will also be presented.

  13. Progress on Development of an Airborne Two-Micron IPDA Lidar for Water Vapor and Carbon Dioxide Column Measurements

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong; Antill, Charles W.; Taylor, Bryant D.; Bowen, Stephen C.; Welters, Angela M.; Remus, Ruben G.; Wong, Teh-Hwa; hide

    2014-01-01

    An airborne 2 micron triple-pulse integrated path differential absorption (IPDA) lidar is currently under development at NASA Langley Research Center (LaRC). This lidar targets both atmospheric carbon dioxide (CO2) and water vapor (H2O) column measurements, simultaneously. Advancements in the development of this IPDA lidar are presented in this paper. Updates on advanced two-micron triple-pulse high-energy laser transmitter will be given including packaging and lidar integration status. In addition, receiver development updates will also be presented. This includes a state-of-the-art detection system integrated at NASA Goddard Space Flight Center. This detection system is based on a newly developed HgCdTe (MCT) electron-initiated avalanche photodiode (e-APD) array. Future plan for IPDA lidar system for ground integration, testing and flight validation will be discussed.

  14. Experimental and numerical study of the degradation of radioactive measurements in the filters of airborne radioactive surveillance systems

    Geryes, Tony

    2009-01-01

    The measurement of radioactivity in the filters of airborne radioactive surveillance systems is a major metrology difficulty due to the fact that the absorption of a radiation in the filter media and the mass of aerosols accumulated distort the nuclear counting response. This thesis focuses on the determination of correction factors for the radioactivity loss in the survey filters. In a first step, radioactive filters representing the atmospheric samples have been prepared using the nuclear test bench ICARE. The experimental study on reference filters provided a database to determine correction factors for various filtration conditions. The second part proposes a new numerical method developed to determine the correction factors. It consists of coupling GeoDict for particles filtration simulations and MCNPX simulations for a transport in matter. The good agreement obtained by comparing the numerical and experimental correction factors has permitted to validate the numerical model

  15. Real-time measurements of airborne biologic particles using fluorescent particle counter to evaluate microbial contamination: results of a comparative study in an operating theater.

    Dai, Chunyang; Zhang, Yan; Ma, Xiaoling; Yin, Meiling; Zheng, Haiyang; Gu, Xuejun; Xie, Shaoqing; Jia, Hengmin; Zhang, Liang; Zhang, Weijun

    2015-01-01

    Airborne bacterial contamination poses a risk for surgical site infection, and routine surveillance of airborne bacteria is important. Traditional methods for detecting airborne bacteria are time consuming and strenuous. Measurement of biologic particle concentrations using a fluorescent particle counter is a novel method for evaluating air quality. The current study was to determine whether the number of biologic particles detected by the fluorescent particle counter can be used to indicate airborne bacterial counts in operating rooms. The study was performed in an operating theater at a university hospital in Hefei, China. The number of airborne biologic particles every minute was quantified using a fluorescent particle counter. Microbiologic air sampling was performed every 30 minutes using an Andersen air sampler (Pusong Electronic Instruments, Changzhou, China). Correlations between the 2 different methods were analyzed by Pearson correlation coefficients. A significant correlation was observed between biologic particle and bacterial counts (Pearson correlation coefficient = 0.76), and the counting results from 2 methods both increased substantially between operations, corresponding with human movements in the operating room. Fluorescent particle counters show potential as important tools for monitoring bacterial contamination in operating theatres. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  16. Comparative evaluation of three impactor samplers for measuring airborne bacteria and fungi concentrations.

    Méheust, Delphine; Gangneux, Jean-Pierre; Cann, Pierre Le

    2013-01-01

    Portable microbial samplers are useful for detecting microorganisms in the air. However, limited data are available on their performance when sampling airborne biological agents in a routine practice. We compared bacterial and fungal concentrations obtained in field conditions using three impactor samplers with different designs (AES Chemunex Sampl'Air, bioMérieux Air Ideal, and Sartorius AirPort MD8/BACTair). The linearity of mold collection was tested in the range of 100 L to 1000 L, and all the devices had a correlation coefficient higher than 0.95. For optimal comparison of the samplers, we performed experiments in different hospital rooms with varying levels of air biocontamination. Each sampling procedure was repeated to assess reproducibility. No significant difference between the samplers was observed for the mold concentrations on Sabouraud agar, whereas Sampl'Air collected significantly more bacteria on tryptic soy agar than Air Ideal or BACTair at one of the sites. Impactor location in the room was nevertheless associated with the variability observed with the three samplers at the highest microbial concentration levels. On the basis of their performance, autonomy and simplicity of use, these three impactors are suitable for routine indoor evaluation of microbial air contamination.

  17. Spectrometric devices of itinerant radiometric laboratory

    Dolgirev, E.I.; Moroz, G.L.; Shchedrin, D.A.

    1978-01-01

    Scintillation gamma-spectrometer is described designed for mobile radiometric laboratory for individual monitoring of internal γ-radiation of members of the general population and service personnel as well as for analysis of the isotopic composition of radiocontaminants in the environment. Description and technical features of device are given. The detection unit consists of detectors made on the basis of NaI(Tl) monocrystals 63 x 63 mm in size. The unit permits measurement of various levels of gamma-emitting nuclides throughout the body and in the thyroid and lungs of man. Provision is made for measuring samples with high specific activities (more than 10 -5 Cu/g) and for examining individuals having high levels of incorporated radionuclides

  18. Studying the influence of temperature and pressure on microphysical properties of mixed-phase clouds using airborne measurements

    Andreea, Boscornea; Sabina, Stefan; Sorin-Nicolae, Vajaiac; Mihai, Cimpuieru

    2015-04-01

    One cloud type for which the formation and evolution process is not well-understood is the mixed-phase type. In general mixed-phase clouds consist of liquid droplets and ice crystals. The temperature interval within both liquid droplets and ice crystals can potentially coexist is limited to 0 °C and - 40 °C. Mixed-phase clouds account for 20% to 30% of the global cloud coverage. The need to understand the microphysical characteristics of mixed-phase clouds to improve numerical forecast modeling and radiative transfer calculation is of major interest in the atmospheric community. In the past, studies of cloud phase composition have been significantly limited by a lack of aircraft instruments capable of discriminating between the ice and liquid phase for a wide range of particle sizes. Presently, in situ airborne measurements provide the most accurate information about cloud microphysical characteristics. This information can be used for verification of both numerical models and cloud remote-sensing techniques. The knowledge of the temperature and pressure variation during the airborne measurements is crucial in order to understand their influence on the cloud dynamics and also their role in the cloud formation processes like accretion and coalescence. Therefore, in this paper is presented a comprehensive study of cloud microphysical properties in mixed-phase clouds in focus of the influence of temperature and pressure variation on both, cloud dynamics and the cloud formation processes, using measurements performed with the ATMOSLAB - Airborne Laboratory for Environmental Atmospheric Research in property of the National Institute for Aerospace Research "Elie Carafoli" (INCAS). The airborne laboratory equipped for special research missions is based on a Hawker Beechcraft - King Air C90 GTx aircraft and is equipped with a sensors system CAPS - Cloud, Aerosol and Precipitation Spectrometer (30 bins, 0.51-50 µm) and a HAWKEYE cloud probe. The analyzed data in this

  19. Use of field-portable X-ray fluorescence (FPXRF) analyzer to measure airborne lead levels in Korean workplaces.

    Kim, Nam-Soo; Kim, Jin-Ho; Ahn, Kyu-Dong; Lee, Byung-Kook

    2007-11-01

    We evaluated the possibility of applying field-portable x-ray fluorescence (FPXRF) analysis as a rapid, on-site and near real-time method for evaluating airborne lead contamination in Korean workplaces. A total of 287 airborne lead filter samples were measured in 12 lead-using workplaces during routine industrial hygienic monitoring procedures as required by Korean government regulations. All filter samples were collected using the standard industrial hygiene sampling protocol described in NIOSH Method 7300 using closed-face 37-mm cassettes with preloaded cellulose ester membrane filters with a pore size of 0.8 microm. The samples were first analyzed using the non-destructive, FPXRF analytical method (NIOSH method 7702), and then subsequently analyzed using inductively coupled plasma atomic emission spectrophotometry (ICP) (NIOSH method 7300) as a reference analytical method. Pair-wise comparison of filter samples using the paired t-test revealed no statistically significant differences between the two methods over a wide range of airborne lead levels (0.018-0.201 microg/m(3)) either over the industries assessed or separately in the 12 lead-using workplaces. Linear regression of the data between the ICP and FPXRF methods produced a slope of 1.03, a y-intercept of 0.13 microg/sample, and a coefficient of determinant (r(2)) of 0.975 for all the data. For samples in the range from 0 to 100 microg, the corresponding values were 1.07, -1.20 microg/sample, and 0.925, respectively. There were no significant differences in the regression analyses of the three industry types (r(2)=0.964-0.982). Our data suggest that FPXRF data are highly correlated with those from the laboratory-based ICP method in terms of accuracy, precision, and bias. Therefore, FPXRF can be used for the rapid, on-site analysis of lead air-filter samples for values up to 26 microg/sample prior to laboratory confirmation by the ICP method.

  20. Radiometric calibration of the in-flight blackbody calibration system of the GLORIA interferometer

    C. Monte

    2014-01-01

    Atmosphere is an airborne, imaging, infrared Fourier transform spectrometer that applies the limb-imaging technique to perform trace gas and temperature measurements in the Earth's atmosphere with three-dimensional resolution. To ensure the traceability of these measurements to the International Temperature Scale and thereby to an absolute radiance scale, GLORIA carries an on-board calibration system. Basically, it consists of two identical large-area and high-emissivity infrared radiators, which can be continuously and independently operated at two adjustable temperatures in a range from −50 °C to 0 °C during flight. Here we describe the radiometric and thermometric characterization and calibration of the in-flight calibration system at the Reduced Background Calibration Facility of the Physikalisch-Technische Bundesanstalt. This was performed with a standard uncertainty of less than 110 mK. Extensive investigations of the system concerning its absolute radiation temperature and spectral radiance, its temperature homogeneity and its short- and long-term stability are discussed. The traceability chain of these measurements is presented.

  1. Laboratory-based bidirectional reflectance distribution functions of radiometric tarps

    Georgiev, Georgi T.; Butler, James J.

    2008-01-01

    Laboratory-based bidirectional reflectance distribution functions (BRDFs) of radiometric tarp samples used in the vicarious calibration of Earth remote sensing satellite instruments are presented in this paper. The results illustrate the BRDF dependence on the orientation of the tarps' weft and warp threads. The study was performed using the GSFC scatterometer at incident zenith angles of 0 deg., 10 deg., and 30 deg.; scatter zenith angles from 0 deg. to 60 deg.; and scatter azimuth angles of 0 deg., 45 deg., 90 deg., 135 deg., and 180 deg.. The wavelengths were 485 nm, 550 nm, 633 nm, and 800 nm. The tarp's weft and warp dependence on BRDF is well defined at all measurement geometries and wavelengths. The BRDF difference can be as high as 8% at 0 deg. incident angle and 12% at 30 deg. incident angle. The fitted BRDF data show a very small discrepancy from the measured ones. New data on the forward and backscatter properties of radiometric tarps are reported. The backward scatter is well pronounced for the white samples. The black sample has well-pronounced forward scatter. The provided BRDF characterization of radiometric tarps is an excellent reference for anyone interested in using tarps for radiometric calibrations. The results are NIST traceable

  2. Laboratory-based bidirectional reflectance distribution functions of radiometric tarps.

    Georgiev, Georgi T; Butler, James J

    2008-06-20

    Laboratory-based bidirectional reflectance distribution functions (BRDFs) of radiometric tarp samples used in the vicarious calibration of Earth remote sensing satellite instruments are presented in this paper. The results illustrate the BRDF dependence on the orientation of the tarps' weft and warp threads. The study was performed using the GSFC scatterometer at incident zenith angles of 0 degrees, 10 degrees, and 30 degrees; scatter zenith angles from 0 degrees to 60 degrees; and scatter azimuth angles of 0 degrees, 45 degrees, 90 degrees, 135 degrees, and 180 degrees. The wavelengths were 485 nm, 550 nm, 633 nm, and 800 nm. The tarp's weft and warp dependence on BRDF is well defined at all measurement geometries and wavelengths. The BRDF difference can be as high as 8% at 0 degrees incident angle and 12% at 30 degrees incident angle. The fitted BRDF data show a very small discrepancy from the measured ones. New data on the forward and backscatter properties of radiometric tarps are reported. The backward scatter is well pronounced for the white samples. The black sample has well-pronounced forward scatter. The provided BRDF characterization of radiometric tarps is an excellent reference for anyone interested in using tarps for radiometric calibrations. The results are NIST traceable.

  3. Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: Retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA F...

  4. Airborne Measurements of CO2 Column Absorption and Range Using a Pulsed Direct-Detection Integrated Path Differential Absorption Lidar

    Abshire, James B.; Riris, Haris; Weaver, Clark J.; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Browell, Edward V.

    2013-01-01

    We report on airborne CO2 column absorption measurements made in 2009 with a pulsed direct-detection lidar operating at 1572.33 nm and utilizing the integrated path differential absorption technique. We demonstrated these at different altitudes from an aircraft in July and August in flights over four locations in the central and eastern United States. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. The lidar measurement statistics were also calculated for each flight as a function of altitude. The optical depth varied nearly linearly with altitude, consistent with calculations based on atmospheric models. The scatter in the optical depth measurements varied with aircraft altitude as expected, and the median measurement precisions for the column varied from 0.9 to 1.2 ppm. The altitude range with the lowest scatter was 810 km, and the majority of measurements for the column within it had precisions between 0.2 and 0.9 ppm.

  5. Cross-Correlation of Diameter Measures for the Co-Registration of Forest Inventory Plots with Airborne Laser Scanning Data

    Jean-Matthieu Monnet

    2014-09-01

    Full Text Available Continuous maps of forest parameters can be derived from airborne laser scanning (ALS remote sensing data. A prediction model is calibrated between local point cloud statistics and forest parameters measured on field plots. Unfortunately, inaccurate positioning of field measures lead to a bad matching of forest measures with remote sensing data. The potential of using tree diameter and position measures in cross-correlation with ALS data to improve co-registration is evaluated. The influence of the correction on ALS models is assessed by comparing the accuracy of basal area prediction models calibrated or validated with or without the corrected positions. In a coniferous, uneven-aged forest with high density ALS data and low positioning precision, the algorithm co-registers 91% of plots within two meters from the operator location when at least the five largest trees are used in the analysis. The new coordinates slightly improve the prediction models and allow a better estimation of their accuracy. In a forest with various stand structures and species, lower ALS density and differential Global Navigation Satellite System measurements, position correction turns out to have only a limited impact on prediction models.

  6. Coincident Retrieval of Ocean Surface Roughness and Salinity Using Airborne and Satellite Microwave Radiometry and Reflectometry Measurements during the Carolina Offshore (Caro) Experiment.

    Burrage, D. M.; Wesson, J. C.; Wang, D. W.; Garrison, J. L.; Zhang, H.

    2017-12-01

    The launch of the Cyclone Global Navigation Satellite System (CYGNSS) constellation of 8 microsats carrying GPS L-band reflectometers on 15 Dec., 2016, and continued operation of the L-band radiometer on the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) satellite, allow these complementary technologies to coincidentally retrieve Ocean surface roughness (Mean Square Slope, MSS), Surface Wind speed (WSP), and Sea Surface Salinity (SSS). The Carolina Offshore (Caro) airborne experiment was conducted jointly by NRL SSC and Purdue University from 7-11 May, 2017 with the goal of under-flying CYGNSS and SMOS and overflying NOAA buoys, to obtain high-resolution reflectometer and radiometer data for combined retrieval of MSS, SSS and WSP on the continental shelf. Airborne instruments included NRL's Salinity Temperature and Roughness Remote Scanner (STARRS) L-, C- and IR-band radiometer system, and a 4-channel dual-pol L-band (GPS) and S-band (XM radio) reflectometer, built by Purdue University. Flights either crossed NOAA buoys on various headings, or intersected with specular point ground tracks at predicted CYGNSS overpass times. Prevailing winds during Caro were light to moderate (1-8 m/s), so specular returns dominated the reflectometer Delay Doppler Maps (DDMs), and MSS was generally low. In contrast, stronger winds (1-12 m/s) and rougher seas (wave heights 1-5 m) were experienced during the preceding Maine Offshore (Maineo) experiment in March, 2016. Several DDM observables were used to retrieve MSS and WSP, and radiometer brightness temperatures produced Sea Surface Temperature (SST), SSS and also WSP estimates. The complementary relationship of Kirchoff's formula e+r=1, between radiometric emissivity, e, and reflectivity, r, was exploited to seek consistent estimates of MSS, and use it to correct the SSS retrievals for sea surface roughness effects. The relative performance and utility of the various airborne and satellite retrieval algorithms

  7. Airborne radionuclides of concern and their measurement in monitoring a Comprehensive Test Ban Treaty

    Perkins, R.W.; Miley, H.S.; Hensley, W.K.; Abel, K.H.

    1995-01-01

    The U.S. Department of Energy (DOE) is conducting radioanalytical developmental programs with the goal of providing near-real-time analysis technology for airborne signature radionuclides which are indicative of a nuclear weapons test in any of the earth's environments. If a test were conducted in the atmosphere or above the atmosphere, then the full spectrum of fission and activation products, together with residues from the device would be dispersed in the atmosphere. However, if a nuclear test were conducted underground or under water, the emission could range from a major to a very minor vent, and the material released would likely consist mainly of noble gas radionuclides and the radioiodines. Since many of the noble gases decay to form particulate radionuclides, these may serve as the more sensitive signatures. For example, Ba-140 is a daughter of Xe-140 (13.6 s), and Cs-137 is a daughter of Xe-137 (3.82 min). Both of these have been observed in large amounts relative to other fission products in dynamic venting of U.S. underground nuclear detonations. Large amounts of radionuclides are produced from even a comparatively small nuclear detonation. For example, a 10-KT fission device will produce approximately a megacurie of Ba-140 and of several other radionuclides with half-lives of days to weeks. If such a device were detonated in the atmosphere at midlatitude, it would easily be observable at downwind monitoring sites during its first and subsequent circumnavigations of the earth. Efficient and practical methods for the near-real-time analysis of both particulate and gaseous radionuclides are important to an effective monitoring and attribution program in support of a Comprehensive Test Ban Treaty (CTBT); methods for this purpose are being pursued

  8. Regional radiometric map of Syria, using gamma-ray spectrometer

    Aissa, M.; Al-Hent, R.; Nasser, R.

    2005-01-01

    The regional radiometric gamma-ray spectrometry map of Syria, scaled 1/1000000, for surficial concentration of the total radioactivity (Ur), eU, eTh and %K was completely achieved after normalizing the airborne and carbon data sets to match each other. It worthy notice that, the anomalies found to be closely related to either phosphate and/or glauconite deposits. It is worth mentioning that throughout the survey work many scattered occurrences of secondary uranium mineralization were found as spots in some formations and phosphate rocks. Where this phenomena attributes to chemical and physical disseminating instead of accumulating the radioelements. So, that leads to a weak expectation for usual surface uranium deposits where attributed to the oxidizing condition. Then this expectation remains, as an open question requires answering through planning to subsurface prospecting. (Author)

  9. Study and development of an airborne instrument for collecting aerosols and for measuring radon 222 by its active deposition

    Filippi, Dominique

    2000-01-01

    The study and development of an airborne instrument designed to collect aerosols and measure radon 222 is detailed in this thesis. Having discussed the context of radon and introduced the methods of the measurement of radon 222 by its natural active deposition, the measurement of aerosols with the Sextant Avionique/LSCE dynamic iso-kinetic probe is quantified. These estimations of the efficiency of the probe were obtained during iso-axial simulations of the flow around the probe at different sub-sonic speeds, then by the calculation of trajectories of particles at the entrance to the probe for several debit coefficients. The effect of the attack angle is discussed along with the iso-kinetic criteria of pressure necessary for the functioning of this probe. To conclude this theoretical study, the author has estimated the deposits during aerosol transport in pipes. The instrument once constructed, (dubbed A VIRAD), is then itself presented, along with the technological aspects adopted for its use. The instrument was validated during an experimental aerial study STAAARTE 99. The measures obtained during these flights are presented in the conclusions. (author) [fr

  10. A new airborne Polar Nephelometer for the measurement of optical and microphysical cloud properties. Part II: Preliminary tests

    O. Crépel

    Full Text Available A new optical sensor, the airborne Polar Nephelometer, has been tested in an open wind tunnel. The wind tunnel was operated in cloudy conditions including either cloud water droplets or ice crystals, or a mixture of these particles. The sensor is designed to measure the optical and microphysical parameters of cloud particles sized from a few micrometers to about 500 µm diameter. Basically, the probe measures the scattering phase function of an ensemble of cloud particles which intersect a collimated laser beam near the focal point of a paraboloidal mirror. From the measured scattering phase function the retrieval of the droplet-size spectra and subsequent derived quantities such as liquid water content and size parameters can be calculated using an inversion method. The particle phase discrimination (water droplets/ice particles can be derived from the shape of the scattering phase function and the sensitivity of the probe allows the detection of small ice crystals (typically of 5 µm diameter. The paper describes the preliminary results obtained by the prototype version of the Polar Nephelometer in various cloudy conditions. These results are compared with direct microphysical measurements obtained by usual PMS probes also mounted in the wind tunnel. Complementary results obtained in a cold chamber are presented in order to illustrate the reliability of the Polar Nephelometer in the presence of small ice crystals.

  11. A new semiquantitative radiometric opsonin assay

    Yamamura, M.; Valdimarsson, H.

    1978-01-01

    A new semiquantitative radiometric opsonin assay is described. It was found that the opsonin activity generated by incubating brewer's yeast, Saccharomyces cerevisiae, in medium containing less than 5% human serum was exclusively complement dependent. In contrast, C.albicans was effectively opsonized in the absence of complement. Antibodies and the early classical complement pathway did not contribute to the opsonization of S.cerevisiae and neither did C5-9. The brewer's yeast assay can therefore be used for measuring selectively the opsonizing capacity of the alternative pathway. Sera from approximately 7% of apparently healthy adult controls consistently failed to generate significant opsonin activity while 8 out of 26 patients with suspected immune deficiency of unknown cause were defective in this assay. All opsonin deficient sera so far tested had haemolytically normal alternative pathway and Factor B activity. (author)

  12. Mapping of radiation anomalies using UAV mini-airborne gamma-ray spectrometry.

    Šálek, Ondřej; Matolín, Milan; Gryc, Lubomír

    2018-02-01

    Localization of size-limited gamma-ray anomalies plays a fundamental role in uranium prospecting and environmental studies. Possibilities of a newly developed mini-airborne gamma-ray spectrometric equipment were tested on a uranium anomaly near the village of Třebsko, Czech Republic. The measurement equipment was based on a scintillation gamma-ray spectrometer specially developed for unmanned aerial vehicles (UAV) mounted on powerful hexacopter. The gamma-ray spectrometer has two 103 cm 3 BGO scintillation detectors of relatively high sensitivity. The tested anomaly, which is 80 m by 40 m in size, was investigated by ground gamma-ray spectrometric measurement in a detail rectangular measurement grid. Average uranium concentration is 25 mg/kg eU attaining 700 mg/kg eU locally. The mini-airborne measurement across the anomaly was carried out on three 100 m long parallel profiles at eight flight altitudes from 5 to 40 m above the ground. The resulting 1 s 1024 channel gamma-ray spectra, recorded in counts per second (cps), were processed to concentration units of K, U and Th, while total count (TC) was reported in cps. Increased gamma ray intensity of the anomaly was indicated by mini-airborne measurement at all profiles and altitudes, including the highest altitude of 40 m, at which the recorded intensity is close to the natural radiation background. The reported instrument is able to record data with comparable quality as standard airborne survey, due to relative sensitive detector, lower flight altitude and relatively low flight speed of 1 m/s. The presented experiment brings new experience with using unmanned semi-autonomous aerial vehicles and the latest mini-airborne radiometric instrument. The experiment has demonstrated the instrument's ability to localize size-limited uranium anomalies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Modeling of mean radiant temperature based on comparison of airborne remote sensing data with surface measured data

    Chen, Yu-Cheng; Chen, Chih-Yu; Matzarakis, Andreas; Liu, Jin-King; Lin, Tzu-Ping

    2016-06-01

    Assessment of outdoor thermal comfort is becoming increasingly important due to the urban heat island effect, which strongly affects the urban thermal environment. The mean radiant temperature (Tmrt) quantifies the effect of the radiation environment on humans, but it can only be estimated based on influencing parameters and factors. Knowledge of Tmrt is important for quantifying the heat load on human beings, especially during heat waves. This study estimates Tmrt using several methods, which are based on climatic data from a traditional weather station, microscale ground surface measurements, land surface temperature (LST) and light detection and ranging (LIDAR) data measured using airborne devices. Analytical results reveal that the best means of estimating Tmrt combines information about LST and surface elevation information with meteorological data from the closest weather station. The application in this method can eliminate the inconvenience of executing a wide range ground surface measurement, the insufficient resolution of satellite data and the incomplete data of current urban built environments. This method can be used to map a whole city to identify hot spots, and can be contributed to understanding human biometeorological conditions quickly and accurately.

  14. Development of a passive air sampler to measure airborne organophosphorus pesticides and oxygen analogs in an agricultural community.

    Armstrong, Jenna L; Yost, Michael G; Fenske, Richard A

    2014-09-01

    Organophosphorus pesticides are some of the most widely used insecticides in the US, and spray drift may result in human exposures. We investigate sampling methodologies using the polyurethane foam passive air sampling device to measure cumulative monthly airborne concentrations of OP pesticides chlorpyrifos, azinphos-methyl, and oxygen analogs. Passive sampling rates (m(3)d(-1)) were determined using calculations using chemical properties, loss of depuration compounds, and calibration with side-by-side active air sampling in a dynamic laboratory exposure chamber and in the field. The effects of temperature, relative humidity, and wind velocity on outdoor sampling rates were examined at 23 sites in Yakima Valley, Washington. Indoor sampling rates were significantly lower than outdoors. Outdoor rates significantly increased with average wind velocity, with high rates (>4m(3)d(-1)) observed above 8ms(-1). In exposure chamber studies, very little oxygen analog was observed on the PUF-PAS, yet substantial amounts chlorpyrifos-oxon and azinphos methyl oxon were measured in outdoor samples. PUF-PAS is a practical and useful alternative to AAS because it results in little artificial transformation to the oxygen analog during sampling, it provides cumulative exposure estimates, and the measured sampling rates were comparable to rates for other SVOCs. It is ideal for community based participatory research due to low subject burden and simple deployment in remote areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Comparison of Aerosol Classification Results from Airborne High Spectral Resolution Lidar (HSRL) Measurements and the Calipso Vertical Feature Mask

    Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.; Rogers, R. R.; Obland, M. D.; Butler, C. F.; Cook, A. L.; Harper, D. B.; Froyd, K. D.; hide

    2012-01-01

    Knowledge of the vertical profile, composition, concentration, and size of aerosols is required for assessing the direct impact of aerosols on radiation, the indirect effects of aerosols on clouds and precipitation, and attributing these effects to natural and anthropogenic aerosols. Because anthropogenic aerosols are predominantly submicrometer, fine mode fraction (FMF) retrievals from satellite have been used as a tool for deriving anthropogenic aerosols. Although column and profile satellite retrievals of FMF have been performed over the ocean, such retrievals have not yet been been done over land. Consequently, uncertainty in satellite estimates of the anthropogenic component of the aerosol direct radiative forcing is greatest over land, due in large part to uncertainties in the FMF. Satellite measurements have been used to detect and evaluate aerosol impacts on clouds; however, such efforts have been hampered by the difficulty in retrieving vertically-resolved cloud condensation nuclei (CCN) concentration, which is the most direct parameter linking aerosol and clouds. Recent studies have shown correlations between average satellite derived column aerosol optical thickness (AOT) and in situ measured CCN. However, these same studies, as well as others that use detailed airborne in situ measurements have noted that vertical variability of the aerosol distribution, impacts of relative humidity, and the presence of coarse mode aerosols such as dust introduce large uncertainties in such relations.

  16. Retrieval of Cloud Properties from the Multi-spectral, Multi-viewing and Polarized Measurements of the Airborne Polarimeter OSIRIS

    Matar, C.; Cornet, C.; Parol, F.; C-Labonnote, L.; Auriol, F.; Nicolas, J. M.

    2017-12-01

    Clouds are recognized as a major source of uncertainty in forecasting the evolution of climate change. One way to improve our knowledge is to obtain accurate cloud properties and variabilities at high spatial resolution. Airborne remote sensing measurements are very suitable to achieve these targets with a tens of meters resolution. In this context, we exploit multi-viewing measurements of the new airborne radiometer OSIRIS (Observing System Including Polarization in the Solar Infrared Spectrum), developed in the Laboratoire d'Optique Atmosphérique (LOA). It is based on POLDER concept as a prototype of the future spacecraft 3MI (Multi-Viewing Multi-Channel Multi-Polarisation Imaging Mission) that will be part of the EPS-SG Eumetsat-ESA mission. Currently, most operational remote sensing algorithms used to retrieve cloud properties from passive measurements, are based on the construction of pre-calculated Look-Up Tables (LUT) under the hypothesis of a single plane-parallel cloud layer. This assumption leads to certain limitations and possible large errors.We developed an optimal estimation method to retrieve cloud optical thickness and effective radius of cloud droplets. This inversion method is more flexible than the LUT method and allows to take into account uncertainties on both observations and the physical model leading to a direct estimation of the retrievals uncertainties in a well-established formalism. For example, we include uncertainties on retrieved cloud parameters due to an incorrect estimation of the ocean surface winds speed, the cloud vertical profiles and the 3D radiative transfer effects.OSIRIS has two separate optical sensors, one for the visible and near infrared range and the other one for the shortwave infrared (SWIR). Consequently, the developed algorithms are based on two different types of information: (1) the total and polarized multi-viewing reflectances from the visible range and (2) the multi-viewing total reflectances from two SWIR

  17. Microsomal aryl hydrocarbon hydroxylase comparison of the direct, indirect and radiometric assays

    Denison, M.S.; Murray, M.; Wilkinson, C.F.

    1983-01-01

    The direct fluorometric assay of aryl hydrocarbon hydroxlyase has been compared to the more commonly used indirect fluorometric and radiometric assays. Although rat hepatic microsomal activities measured by the direct assay were consistently higher than those obtained by the other assays, the relative changes in activity following enzyme induction and/or inhibition were similar. The direct assay provides an accurate and rapid measure of aryl hydrocarbon hydroxylase activity and avoids several problems inherent in the indirect and radiometric assays. 2 tables

  18. Calibrating airborne measurements of airspeed, pressure and temperature using a Doppler laser air-motion sensor

    W. A. Cooper

    2014-09-01

    Full Text Available A new laser air-motion sensor measures the true airspeed with a standard uncertainty of less than 0.1 m s−1 and so reduces uncertainty in the measured component of the relative wind along the longitudinal axis of the aircraft to about the same level. The calculated pressure expected from that airspeed at the inlet of a pitot tube then provides a basis for calibrating the measurements of dynamic and static pressure, reducing standard uncertainty in those measurements to less than 0.3 hPa and the precision applicable to steady flight conditions to about 0.1 hPa. These improved measurements of pressure, combined with high-resolution measurements of geometric altitude from the global positioning system, then indicate (via integrations of the hydrostatic equation during climbs and descents that the offset and uncertainty in temperature measurement for one research aircraft are +0.3 ± 0.3 °C. For airspeed, pressure and temperature, these are significant reductions in uncertainty vs. those obtained from calibrations using standard techniques. Finally, it is shown that although the initial calibration of the measured static and dynamic pressures requires a measured temperature, once calibrated these measured pressures and the measurement of airspeed from the new laser air-motion sensor provide a measurement of temperature that does not depend on any other temperature sensor.

  19. Advances in High Energy Solid-State Pulsed 2-Micron Lidar Development for Ground and Airborne Wind, Water Vapor and CO2 Measurements

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Refaat, Tamer; Kavaya, Michael J.; Remus, Ruben

    2015-01-01

    NASA Langley Research Center has a long history of developing 2-micron lasers. From fundamental spectroscopy research, theoretical prediction of new materials, laser demonstration and engineering of lidar systems, it has been a very successful program spanning around two decades. Successful development of 2-micron lasers has led to development of a state-of-the-art compact lidar transceiver for a pulsed coherent Doppler lidar system for wind measurement with an unprecedented laser pulse energy of 250 millijoules in a rugged package. This high pulse energy is produced by a Ho:Tm:LuLiF laser with an optical amplifier. While the lidar is meant for use as an airborne instrument, ground-based tests were carried out to characterize performance of the lidar. Atmospheric measurements will be presented, showing the lidar's capability for wind measurement in the atmospheric boundary layer and free troposphere. Lidar wind measurements are compared to a balloon sonde, showing good agreement between the two sensors. Similar architecture has been used to develop a high energy, Ho:Tm:YLF double-pulsed 2-micron Integrated Differential Absorption Lidar (IPDA) instrument based on direct detection technique that provides atmospheric column CO2 measurements. This instrument has been successfully used to measure atmospheric CO2 column density initially from a ground mobile lidar trailer, and then it was integrated on B-200 plane and 20 hours of flight measurement were made from an altitude ranging 1500 meters to 8000 meters. These measurements were compared to in-situ measurements and National Oceanic and Atmospheric Administration (NOAA) airborne flask measurement to derive the dry mixing ratio of the column CO2 by reflecting the signal by various reflecting surfaces such as land, vegetation, ocean surface, snow and sand. The lidar measurements when compared showed a very agreement with in-situ and airborne flask measurement. NASA Langley Research Center is currently developing a

  20. Radiometric geochronology of the Himalaya

    Saini, H.S.

    1982-01-01

    The radiometric age data obtained by different dating methods have been interpreted in terms of possible orogenic activities prevailing in the Himalaya. In general, the age data confirm four main events, the Precambrian, the Late Precambrian-Cambrian Assyntian (Caledonian), the Late Palaeozoic-Hercynian and the Late Cretaceous-Tertiary Himalayan orogeny. The mineral dates are particularly significant in delineating different phases of the last i.e. the Himalayan orogeny which indicates main activity of the young Himalayan metamorphism around 70 to 50 Ma and followed by a momentous phase of major uplift during 25 to 10 Ma, which was responsible for the rise of the deeper part of the Himalaya into great folds and thrust slices and the formation of nappe structures. (author)

  1. Gamma radiometric survey of Jamaica

    Lalor, G.C.; Robotham, H.; Miller, J.M.; Simpson, P.R.

    1989-01-01

    The results of a total gamma radiometric survey of Jamaica, carried out with car-borne instrumentation, are presented and the data compared with the contents of potassium, thorium and uranium in rocks and in surface (soil, stream-sediment, pan concentrate and water) samples obtained at six sites selected to be representative of the principal rock types and surface environments of Jamaica. The work formed part of an orientation study for a regional geochemical survey of the CARICOM countries of the Caribbean. The initial results indicate that enhanced gamma activity is correlated with enrichment in uranium and thorium, but not potassium, in terra rossa soils and/or bauxite deposits in limestone. Elsewhere, gamma levels are increased on the Above Rocks Cretaceous basement Inlier, where they correlate generally with the presence of volcanogenic sediments and a granodiorite intrusion. The lowest radioactivity was recorded in the vicinity of ultrabasic rocks in the Blue Mountains Inlier. (author)

  2. ARM-ACME V: ARM Airborne Carbon Measurements V on the North Slope of Alaska Field Campaign Report

    Biraud, Sebastien C [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-05-01

    Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols and cloud properties in North Slopes of Alaska (NSA) are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections. From June 1 through September 15, 2015, AAF deployed the G1 research aircraft and flew over the North Slope of Alaska (38 flights, 140 science flight hours), with occasional vertical profiling over Prudhoe Bay, Oliktok point, Barrow, Atqasuk, Ivotuk, and Toolik Lake. The aircraft payload included Picarro and Los Gatos Research (LGR) analyzers for continuous measurements of CO2, CH4, H2O, and CO and N2O mixing ratios, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, and trace hydrocarbon species). The aircraft payload also include measurements of aerosol properties (number size distribution, total number concentration, absorption, and scattering), cloud properties (droplet and ice size information), atmospheric thermodynamic state, and solar/infrared radiation.

  3. Radiometric analyzer with plural radiation sources and detectors

    Arima, S.; Oda, M.; Miyashita, K.; Takada, M.

    1977-01-01

    A radiometric analyzer for measuring characteristics of a material by radiation comprises a plurality of systems in which each consists of a radiation source and a radiation detector which are the same in number as the number of elements of the molecule of the material and a linear calibration circuit having inverse response characteristics (calibration curve) of the respective systems of detectors, whereby the measurement is carried out by four fundamental rules by operation of the mutual outputs of said detector system obtained through said linear calibration circuit. One typical embodiment is a radiometric analyzer for hydrocarbons which measures the density of heavy oil, the sulfur content and the calorific value by three detector systems which include a γ-ray source (E/sub γ/ greater than 50 keV), a soft x-ray source (Ex approximately 20 keV), and a neutron ray source. 2 claims, 6 figures

  4. NASA COAST and OCEANIA Airborne Missions in Support of Ecosystem and Water Quality Research in the Coastal Zone

    Guild, Liane S.; Hooker, Stanford B.; Kudela, Raphael; Morrow, John; Russell, Philip; Myers, Jeffrey; Dunagan, Stephen; Palacios, Sherry; Livingston, John; Negrey, Kendra; hide

    2015-01-01

    Worldwide, coastal marine ecosystems are exposed to land-based sources of pollution and sedimentation from anthropogenic activities including agriculture and coastal development. Ocean color products from satellite sensors provide information on chlorophyll (phytoplankton pigment), sediments, and colored dissolved organic material. Further, ship-based in-water measurements and emerging airborne measurements provide in situ data for the vicarious calibration of current and next generation satellite ocean color sensors and to validate the algorithms that use the remotely sensed observations. Recent NASA airborne missions over Monterey Bay, CA, have demonstrated novel above- and in-water measurement capabilities supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The results characterize coastal atmospheric and aquatic properties through an end-to-end assessment of image acquisition, atmospheric correction, algorithm application, plus sea-truth observations from state-of-the-art instrument systems. The primary goal of the airborne missions was to demonstrate the following in support of calibration and validation exercises for satellite coastal ocean color products: 1) the utility of a multi-sensor airborne instrument suite to assess the bio-optical properties of coastal California, including water quality; and 2) the importance of contemporaneous atmospheric measurements to improve atmospheric correction in the coastal zone. Utilizing an imaging spectrometer optimized in the blue to green spectral domain enables higher signal for detection of the relatively dark radiance measurements from marine and freshwater ecosystem features. The novel airborne instrument, Coastal Airborne In-situ Radiometers (C-AIR) provides measurements of apparent optical properties with high dynamic range and fidelity for deriving exact water leaving radiances at the land-ocean boundary, including radiometrically shallow aquatic

  5. Airborne multi-axis DOAS measurements of tropospheric SO2 plumes in the Po-valley, Italy

    P. Wang

    2006-01-01

    Full Text Available During the second FORMAT (FORMaldehyde as A Tracer of oxidation in the troposphere campaign in 2003 the airborne multi-axis DOAS instrument (AMAXDOAS performed scattered-light spectroscopic measurements of SO2 over the city of Mantova and the power plant Porto Tolle, both situated in the Po-valley, Northern Italy. The SO2 vertical columns and emission flux were derived from two days of measurements, 26 and 27 September 2003. The SO2 emission flux from the power plant Porto Tolle was calculated to 1.93×1025 molec s-1 on 26 September and in good agreement with official emission data, which quote 2.25×1025 molec s-1. On 27 September the measured flux was much lower (3.77×1024 molec s-1 if ECMWF wind data are used, but of comparable magnitude (2.4×1025 molec s-1 if the aircraft on-board wind measurements are utilised. Official emission data was 2.07×1025 molec s-1 indicating only a small change from the previous day. Over the city of Mantova, the observed SO2 vertical columns were 1.1×1016 molec cm-2 and 1.9×1016 molec cm-2 on 26 and 27 September, respectively. This is in good agreement with ground-based measurements of 5.9 ppbv and 10.0 ppbv which correspond to 1.2×1016 molec cm-2 and 2.2×1016 molec cm-2 if a well mixed boundary layer of 500m altitude is assumed.

  6. Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

    I. R. Burling

    2011-12-01

    Full Text Available We have measured emission factors for 19 trace gas species and particulate matter (PM2.5 from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps to close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous observations that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured both the emissions in the convective smoke plume from our airborne platform and the unlofted residual smoldering combustion emissions with our ground-based platform. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including high 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts for smoke that disperses at ground level. We also show that the often ignored unlofted emissions can significantly impact estimates of total emissions. Preliminary evidence suggests large emissions of monoterpenes in the residual smoldering smoke. These data should lead to an improved capacity to model the impacts of biomass burning in similar temperate ecosystems.

  7. Size characterization of airborne SiO2 nanoparticles with on-line and off-line measurement techniques: an interlaboratory comparison study

    Motzkus, C.; Macé, T.; Gaie-Levrel, F.; Ducourtieux, S.; Delvallee, A.; Dirscherl, K.; Hodoroaba, V.-D.; Popov, I.; Popov, O.; Kuselman, I.; Takahata, K.; Ehara, K.; Ausset, P.; Maillé, M.; Michielsen, N.; Bondiguel, S.; Gensdarmes, F.; Morawska, L.; Johnson, G. R.; Faghihi, E. M.; Kim, C. S.; Kim, Y. H.; Chu, M. C.; Guardado, J. A.; Salas, A.; Capannelli, G.; Costa, C.; Bostrom, T.; Jämting, Å. K.; Lawn, M. A.; Adlem, L.; Vaslin-Reimann, S.

    2013-10-01

    Results of an interlaboratory comparison on size characterization of SiO2 airborne nanoparticles using on-line and off-line measurement techniques are discussed. This study was performed in the framework of Technical Working Area (TWA) 34—"Properties of Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS) in the project no. 3 "Techniques for characterizing size distribution of airborne nanoparticles". Two types of nano-aerosols, consisting of (1) one population of nanoparticles with a mean diameter between 30.3 and 39.0 nm and (2) two populations of non-agglomerated nanoparticles with mean diameters between, respectively, 36.2-46.6 nm and 80.2-89.8 nm, were generated for characterization measurements. Scanning mobility particle size spectrometers (SMPS) were used for on-line measurements of size distributions of the produced nano-aerosols. Transmission electron microscopy, scanning electron microscopy, and atomic force microscopy were used as off-line measurement techniques for nanoparticles characterization. Samples were deposited on appropriate supports such as grids, filters, and mica plates by electrostatic precipitation and a filtration technique using SMPS controlled generation upstream. The results of the main size distribution parameters (mean and mode diameters), obtained from several laboratories, were compared based on metrological approaches including metrological traceability, calibration, and evaluation of the measurement uncertainty. Internationally harmonized measurement procedures for airborne SiO2 nanoparticles characterization are proposed.

  8. Size characterization of airborne SiO{sub 2} nanoparticles with on-line and off-line measurement techniques: an interlaboratory comparison study

    Motzkus, C., E-mail: charles.motzkus@lne.fr; Mace, T.; Gaie-Levrel, F.; Ducourtieux, S.; Delvallee, A. [Laboratoire National de Metrologie et d' Essais (LNE) (France); Dirscherl, K. [Danish Fundamental Metrology (DFM) (Denmark); Hodoroaba, V.-D. [BAM Federal Institute for Materials Research and Testing (Germany); Popov, I. [The Hebrew University of Jerusalem, Unit for Nanocharacterization (Israel); Popov, O.; Kuselman, I. [National Physical Laboratory of Israel (INPL) (Israel); Takahata, K.; Ehara, K. [National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ) (Japan); Ausset, P.; Maille, M. [Universite Paris-Est Creteil et Universite Paris-Diderot, Laboratoire Interuniversitaire des Systemes Atmospheriques (LISA), UMR CNRS 7583 (France); Michielsen, N.; Bondiguel, S.; Gensdarmes, F. [Institut de Radioprotection et de Surete Nucleaire (IRSN), PSN-RES, SCA, LPMA (France); Morawska, L.; Johnson, G. R.; Faghihi, E. M. [Queensland University of Technology (QUT), International Laboratory for Air Quality and Health (ILAQH) (Australia); and others

    2013-10-15

    Results of an interlaboratory comparison on size characterization of SiO{sub 2} airborne nanoparticles using on-line and off-line measurement techniques are discussed. This study was performed in the framework of Technical Working Area (TWA) 34-'Properties of Nanoparticle Populations' of the Versailles Project on Advanced Materials and Standards (VAMAS) in the project no. 3 'Techniques for characterizing size distribution of airborne nanoparticles'. Two types of nano-aerosols, consisting of (1) one population of nanoparticles with a mean diameter between 30.3 and 39.0 nm and (2) two populations of non-agglomerated nanoparticles with mean diameters between, respectively, 36.2-46.6 nm and 80.2-89.8 nm, were generated for characterization measurements. Scanning mobility particle size spectrometers (SMPS) were used for on-line measurements of size distributions of the produced nano-aerosols. Transmission electron microscopy, scanning electron microscopy, and atomic force microscopy were used as off-line measurement techniques for nanoparticles characterization. Samples were deposited on appropriate supports such as grids, filters, and mica plates by electrostatic precipitation and a filtration technique using SMPS controlled generation upstream. The results of the main size distribution parameters (mean and mode diameters), obtained from several laboratories, were compared based on metrological approaches including metrological traceability, calibration, and evaluation of the measurement uncertainty. Internationally harmonized measurement procedures for airborne SiO{sub 2} nanoparticles characterization are proposed.

  9. Size characterization of airborne SiO2 nanoparticles with on-line and off-line measurement techniques: an interlaboratory comparison study

    Motzkus, C.; Macé, T.; Gaie-Levrel, F.; Ducourtieux, S.; Delvallee, A.; Dirscherl, K.; Hodoroaba, V.-D.; Popov, I.; Popov, O.; Kuselman, I.; Takahata, K.; Ehara, K.; Ausset, P.; Maillé, M.; Michielsen, N.; Bondiguel, S.; Gensdarmes, F.; Morawska, L.; Johnson, G. R.; Faghihi, E. M.

    2013-01-01

    Results of an interlaboratory comparison on size characterization of SiO 2 airborne nanoparticles using on-line and off-line measurement techniques are discussed. This study was performed in the framework of Technical Working Area (TWA) 34—“Properties of Nanoparticle Populations” of the Versailles Project on Advanced Materials and Standards (VAMAS) in the project no. 3 “Techniques for characterizing size distribution of airborne nanoparticles”. Two types of nano-aerosols, consisting of (1) one population of nanoparticles with a mean diameter between 30.3 and 39.0 nm and (2) two populations of non-agglomerated nanoparticles with mean diameters between, respectively, 36.2–46.6 nm and 80.2–89.8 nm, were generated for characterization measurements. Scanning mobility particle size spectrometers (SMPS) were used for on-line measurements of size distributions of the produced nano-aerosols. Transmission electron microscopy, scanning electron microscopy, and atomic force microscopy were used as off-line measurement techniques for nanoparticles characterization. Samples were deposited on appropriate supports such as grids, filters, and mica plates by electrostatic precipitation and a filtration technique using SMPS controlled generation upstream. The results of the main size distribution parameters (mean and mode diameters), obtained from several laboratories, were compared based on metrological approaches including metrological traceability, calibration, and evaluation of the measurement uncertainty. Internationally harmonized measurement procedures for airborne SiO 2 nanoparticles characterization are proposed

  10. Using Airborne Lidar Data from IcePod to Measure Annual and Seasonal Ice Changes Over Greenland

    Frearson, N.; Bertinato, C.; Das, I.

    2014-12-01

    The IcePod is a multi-sensor airborne science platform that supports a wide suite of instruments, including a Riegl VQ-580 infrared scanning laser, GPS-inertial positioning system, shallow and deep-ice radars, visible-wave and infrared cameras, and upward-looking pyrometer. These instruments allow us to image the ice from top to bottom, including the surface of melt-water plumes that originate at the ice-ocean boundary. In collaboration with the New York Air National Guard 109th Airlift Wing, the IcePod is flown on LC-130 aircraft, which presents the unique opportunity to routinely image the Greenland ice sheet several times within a season. This is particularly important for mass balance studies, as we can measure elevation changes during the melt season. During the 2014 summer, laser data was collected via IcePod over the Greenland ice sheet, including Russell Glacier, Jakobshavn Glacier, Eqip Glacier, and Summit Camp. The Icepod will also be routinely operated in Antarctica. We present the initial testing, calibration, and error estimates from the first set of laser data that were collected on IcePod. At a survey altitude of 1000 m, the laser swath covers ~ 1000 m. A Northrop-Grumman LN-200 tactical grade IMU is rigidly attached to the laser scanner to provide attitude data at a rate of 200 Hz. Several methods were used to determine the lever arm between the IMU center of navigation and GPS antenna phase center, terrestrial scanning laser, total station survey, and optimal estimation. Additionally, initial bore sight calibration flights yielded misalignment angles within an accuracy of ±4 cm. We also performed routine passes over the airport ramp in Kangerlussuaq, Greenland, comparing the airborne GPS and Lidar data to a reference GPS-based ground survey across the ramp, spot GPS points on the ramp and a nearby GPS base station. Positioning errors can severely impact the accuracy of a laser altimeter when flying over remote regions such as across the ice sheets

  11. Airborne gamma spectrometry measurements in the context of the exercise ARM02; Aeroradiometrische Messungen im Rahmen der Uebung ARM02

    Bucher, B.; Rybach, L. [ETH Zuerich (Switzerland); Schwarz, G. [Swiss Nuclear Safety Authority, Villigen (Switzerland); Baerlocher, C. [ETH Zuerich (Switzerland)

    2003-05-01

    The international exercise under the European Union project ECCOMAGS (European Coordination and Calibration of Mobile and Airborne Gamma Spectrometry) stood in the centre of the yearly airborne gamma spectrometry measurement flights which were carried out in the time of 27 -31 May 2002. The exercise was held in Southwest Scotland in the region of Dumfries and Galloway. Unfortunately due to difficulties with flight approvals for military aircrafts data could be taken in the exercise area only on the flight back to Switzerland. Immediately after returning to Switzerland the regular measurements around the nuclear power plants Beznau (KKB) and Leibstadt (KKL), around the intermediate storage facilities for radioactive waste (ZWILAG) and around the research facility Paul Scherrer Institute were performed. The flights took place in the context of the exercise ARM02 and were lead by the Swiss National Emergency Operations Centre (NAZ). Unfortunately just a few measurements in the common intercalibration areas could be taken on the flight back from the international exercise. Nevertheless comparisons of the results with those of other European teams could be made. These comparisons proved the good calibration of our equipment. On the flight back measurements were also carried out at great altitude above the sea. This data allowed to determine very well the background of the aircraft and the cosmic stripping ratios. In the context of the regular measurements in the environs of the nuclear facilities in Switzerland the areas around the nuclear power plants Beznau and Leibstadt and around the nuclear research facility Paul Scherrer Institute were measured. The results were very similar to the results of earlier measurements in the last years. The nuclear power plant Beznau couldn't be recognised on the activity maps. But the nuclear power plant Leibstadt could be identified by its direct radiation which is specific for this type of reactor (BWR). At the site of the Paul

  12. Secondary Aerosol Formation over the ESCOMPTE Area: Results from airborne Aerosol and Trace Gas Measurements

    van Dingenen, R.; Martins-Dos Santos, S.; Putaud, J. P.; Allet, C.; Bretton, E.; Perros, P.

    2003-04-01

    From June 10th to July 14th 2001, the ESCOMPTE campaign took place in the Marseille-Berre area in Southern France. The goal of the campaign was to produce a high quality 3-D data base from emissions, transport and air composition measurements during urban photochemical pollution episodes at the meso-scale. The CAATER AEROPLUM project was embedded within this international field campaign. AEROPLUM aimed at mapping size distributions of aerosols and photo-oxidants in the mixed layer over the ESCOMPTE domain, using the ARAT Fokker 27 as measurement platform. Aircraft sub-micrometer aerosol measurements are validated during overpasses against ground-based measurements, carried out with similar instrumentation. We will present and discuss data during periods of seabreeze, transporting coastal industrial and urban pollution land-inwards. This leads to intense photochemical activity, evidenced by elevated O_3 concentrations and aerosol levels.

  13. Fast in situ airborne measurement of ammonia using a mid-infrared off-axis ICOS spectrometer.

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

    2013-09-17

    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. 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.

  14. Hydroxyl radicals in the tropical troposphere over the Suriname rainforest: airborne measurements

    M. Martinez

    2010-04-01

    Full Text Available Direct measurements of OH and HO2 over a tropical rainforest were made for the first time during the GABRIEL campaign in October 2005, deploying the custom-built HORUS instrument (HydrOxyl Radical measurement Unit based on fluorescence Spectroscopy, adapted to fly in a Learjet wingpod. Biogenic hydrocarbon emissions were expected to strongly reduce the OH and HO2 mixing ratios as the air is transported from the ocean over the forest. However, surprisingly high mixing ratios of both OH and HO2 were encountered in the boundary layer over the rainforest.

    The HORUS instrumentation and calibration methods are described in detail and the measurement results obtained are discussed. The extensive dataset collected during GABRIEL, including measurements of many other trace gases and photolysis frequencies, has been used to quantify the main sources and sinks of OH. Comparison of these measurement-derived formation and loss rates of OH indicates strong previously overlooked recycling of OH in the boundary layer over the tropical rainforest, occurring in chorus with isoprene emission.

  15. Airborne Spectral Measurements of Surface-Atmosphere Anisotropy for Arctic Sea Ice and Tundra

    Arnold, G. Thomas; Tsay, Si-Chee; King, Michael D.; Li, Jason Y.; Soulen, Peter F.

    1999-01-01

    Angular distributions of spectral reflectance for four common arctic surfaces: snow-covered sea ice, melt-season sea ice, snow-covered tundra, and tundra shortly after snowmelt were measured using an aircraft based, high angular resolution (1-degree) multispectral radiometer. Results indicate bidirectional reflectance is higher for snow-covered sea ice than melt-season sea ice at all wavelengths between 0.47 and 2.3 pm, with the difference increasing with wavelength. Bidirectional reflectance of snow-covered tundra is higher than for snow-free tundra for measurements less than 1.64 pm, with the difference decreasing with wavelength. Bidirectional reflectance patterns of all measured surfaces show maximum reflectance in the forward scattering direction of the principal plane, with identifiable specular reflection for the melt-season sea ice and snow-free tundra cases. The snow-free tundra had the most significant backscatter, and the melt-season sea ice the least. For sea ice, bidirectional reflectance changes due to snowmelt were more significant than differences among the different types of melt-season sea ice. Also the spectral-hemispherical (plane) albedo of each measured arctic surface was computed. Comparing measured nadir reflectance to albedo for sea ice and snow-covered tundra shows albedo underestimated 5-40%, with the largest bias at wavelengths beyond 1 pm. For snow-free tundra, nadir reflectance underestimates plane albedo by about 30-50%.

  16. ARM Airborne Carbon Measurements VI (ARM-ACME VI) Field Campaign Report

    Biraud, Sebastien [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-05-01

    From October 1, 2015 through September 30, 2016, AAF deployed a Cessna 206 aircraft over the Southern Great Plains, collecting observations of trace gas mixing ratios over the ARM/SGP Central Facility. The aircraft payload included two Atmospheric Observing Systems (AOS Inc.) analyzers for continuous measurements of CO2, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2). The aircraft payload also includes solar/infrared radiation measurements. This research (supported by DOE ARM and TES programs) builds upon previous ARM-ACME missions. The goal of these measurements is to improve understanding of: (a) the carbon exchange of the ARM region; (b) how CO2 and associated water and energy fluxes influence radiative forcing, convective processes, and CO2 concentrations over the ARM region, and (c) how greenhouse gases are transported on continental scales.

  17. Husbandry Emissions Estimation: Fusion of Mobile Surface and Airborne Remote Sensing and Mobile Surface In Situ Measurements

    Leifer, I.; Hall, J. L.; Melton, C.; Tratt, D. M.; Chang, C. S.; Buckland, K. N.; Frash, J.; Leen, J. B.; Van Damme, M.; Clarisse, L.

    2017-12-01

    Emissions of methane and ammonia from intensive animal husbandry are important drivers of climate and photochemical and aerosol pollution. Husbandry emission estimates are somewhat uncertain because of their dependence on practices, temperature, micro-climate, and other factors, leading to variations in emission factors up to an order-of-magnitude. Mobile in situ measurements are increasingly being applied to derive trace gas emissions by Gaussian plume inversion; however, inversion with incomplete information can lead to erroneous emissions and incorrect source location. Mobile in situ concentration and wind data and mobile remote sensing column data from the Chino Dairy Complex in the Los Angeles Basin were collected near simultaneously (within 1-10 s, depending on speed) while transecting plumes, approximately orthogonal to winds. This analysis included airborne remote sensing trace gas information. MISTIR collected vertical column FTIR data simultaneously with in situ concentration data acquired by the AMOG-Surveyor while both vehicles traveled in convoy. The column measurements are insensitive to the turbulence characterization needed in Gaussian plume inversion of concentration data and thus provide a flux reference for evaluating in situ data inversions. Four different approaches were used on inversions for a single dairy, and also for the aggregate dairy complex plume. Approaches were based on differing levels of "knowledge" used in the inversion from solely the in situ platform and a single gas to a combination of information from all platforms and multiple gases. Derived dairy complex fluxes differed significantly from those estimated by other studies of the Chino complex. Analysis of long term satellite data showed that this most likely results from seasonality effects, highlighting the pitfalls of applying annualized extensions of flux measurements to a single campaign instantiation.

  18. Very low emissions of airborne particulate pollutants measured from two municipal solid waste incineration plants in Switzerland

    Setyan, Ari; Patrick, Michael; Wang, Jing

    2017-10-01

    A field campaign has been performed in two municipal solid waste incineration (MSWI) plants in Switzerland, at Hinwil (ZH) and Giubiasco (TI). The aim was to measure airborne pollutants at different locations of the abatement systems (including those released from the stacks into the atmosphere) and at a near-field (∼1 km) downwind site, in order to assess the efficiency of the abatement systems and the environmental impact of these plants. During this study, we measured the particle number concentration with a condensation particle counter (CPC), and the size distribution with a scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS). We also sampled particles on filters for subsequent analyses of the morphology, size and elemental composition with a scanning electron microscope coupled to an energy dispersive X-ray spectroscope (SEM/EDX), and of water soluble ions by ion chromatography (IC). Finally, volatile organic compounds (VOCs) were sampled on adsorbing cartridges and analyzed by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS), and a portable gas analyzer was used to monitor NO, SO2, CO, CO2, and O2. The particle concentration decreased significantly at two locations of the plants: at the electrostatic precipitator and the bag-house filter. The particle concentrations measured at the stacks were very low (incinerators. At Giubiasco, no significant differences were observed for the morphology and chemical composition of the particles collected in the ambient background and at the downwind site, suggesting that the incineration plant released very limited amounts of particles to the surrounding areas.

  19. Airborne measurements of turbulent trace gas fluxes and analysis of eddy structure in the convective boundary layer over complex terrain

    Hasel, M.; Kottmeier, Ch.; Corsmeier, U.; Wieser, A.

    2005-03-01

    Using the new high-frequency measurement equipment of the research aircraft DO 128, which is described in detail, turbulent vertical fluxes of ozone and nitric oxide have been calculated from data sampled during the ESCOMPTE program in the south of France. Based on airborne turbulence measurements, radiosonde data and surface energy balance measurements, the convective boundary layer (CBL) is examined under two different aspects. The analysis covers boundary-layer convection with respect to (i) the control of CBL depth by surface heating and synoptic scale influences, and (ii) the structure of convective plumes and their vertical transport of ozone and nitric oxides. The orographic structure of the terrain causes significant differences between planetary boundary layer (PBL) heights, which are found to exceed those of terrain height variations on average. A comparison of boundary-layer flux profiles as well as mean quantities over flat and complex terrain and also under different pollution situations and weather conditions shows relationships between vertical gradients and corresponding turbulent fluxes. Generally, NO x transports are directed upward independent of the terrain, since primary emission sources are located near the ground. For ozone, negative fluxes are common in the lower CBL in accordance with the deposition of O 3 at the surface. The detailed structure of thermals, which largely carry out vertical transports in the boundary layer, are examined with a conditional sampling technique. Updrafts mostly contain warm, moist and NO x loaded air, while the ozone transport by thermals alternates with the background ozone gradient. Evidence for handover processes of trace gases to the free atmosphere can be found in the case of existing gradients across the boundary-layer top. An analysis of the size of eddies suggests the possibility of some influence of the heterogeneous terrain in mountainous area on the length scales of eddies.

  20. Measurement of the electrostatic charge in airborne particles: I - development of the equipment and preliminary results

    Marra Jr. W.D.

    2000-01-01

    Full Text Available The design and construction of a equipment capable of measuring the electrostatic charges in aerosols, named the electrostatic charge classifier, were carried out. They were based on the concept of particle electromobility and the charge classifier was intended to classify the nature and the distribution of electrostatic charges as a function of particle size. The resulting piece of equipment is easy to dismount, which facilitates its cleaning and transport, and easy to operate. Early results indicate that the values of electrostatic charge measured on test particles are inside the range reported in the literature, indicating the adequacy of the technique utilized.

  1. The Radiometric Bode's law and Extrasolar Planets

    Lazio, T. J; Farrell, W. M; Dietrick, Jill; Greenlees, Elizabeth; Hogan, Emily; Jones, Christopher; Hennig, L. A

    2004-01-01

    We predict the radio flux densities of the extrasolar planets in the current census, making use of an empirical relation the radiometric Bode's law determined from the five "magnetic" planets in the solar system...

  2. Ash content of lignites - radiometric analysis

    Leonhardt, J.; Thuemmel, H.W.

    1986-01-01

    The quality of lignites is governed by the ash content varying in dependence upon the geologic conditions. Setup and function of the radiometric devices being used for ash content analysis in the GDR are briefly described

  3. Modified and reverse radiometric flow injection analysis

    Myint, U; Ba, H; Khin, M M; Aung, K; Thida, [Yangon Univ. (Myanmar). Dept. of Chemistry; Toelgyessy, J [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Environmental Science

    1994-06-01

    Determination of [sup 137]Cs and [sup 60]Co by using modified and reverse radiometric flow injection analysis is described. Two component RFIA was also realized using [sup 60]Co and [sup 137]Cs radionuclides. (author) 2 refs.; 5 figs.

  4. Comparison between airborne pollution measurement and calculation at 14 measuring points in the Federal State of Brandenburg; Vergleich Immissionsmessung - Immissionsberechnung fuer 14 verkehrsnahe Messpunkte im Land Brandenburg

    Friedrich, U. [Landesumweltamt Brandenburg, Potsdam (Germany). Abt. Immissionsschutz; Schierbaum, I. [Landesumweltamt Brandenburg, Potsdam (Germany). Abt. Immissionsschutz

    1997-02-01

    Airborne pollution measurements for the pollutants benzene and soot were carried out at 14 inner-city measuring points, close to traffic, in the Federal State of Brandenburg, using a distribution model for ideal build-up streets (CPB model) and a model assuming missing fringe buildings (Gauss model). The calculated annual mean values were compared with the measured annual mean values. Benzene: The annual mean values calculated with the help of the CPB model diverged from the measured annual mean values by {+-}25%, apart from one exception. Soot: The calculated annual mean values were always lower than the measured annual mean values. Emission-sources not considered in the calculation (tyre abrasion, secondary dust) are assumed to be the main cause for this difference. (orig.) [Deutsch] Es wurden an 14 innerstaedtischen verkehrsnahen Messpunkten im Land Brandenburg mit einem Ausbreitungsmodell fuer ideale Strassenschluchten (CPB-Modell) und einem Modell unter der Annahme fehlender Randbebauung (Gauss-Modell) Immissionsberechnungen fuer die Schadstoffe Benzol und Russ durchgefuehrt. Benzol: Die mittels CPB-Modell berechneten Jahresmittelwerte wichen bis auf eine Ausnahme maximal um {+-}25% von den Jahresmitteln der Messergebnisse ab. Russ: Die berechneten Jahremittel wiesen stets geringere Werte als die Jahresmittelwerte der Messung auf. Als Hauptursache fuer diese Differenz werden Emissionsquellen vermutet, die nicht bei der Berechnung beruecksichtigt wurden (Reifenabrieb, Sekundaerstaub). (orig.)

  5. Measurement of airborne gunshot particles in a ballistics laboratory by sector field inductively coupled plasma mass spectrometry.

    Diaz, Ernesto; Sarkis, Jorge E Souza; Viebig, Sônia; Saldiva, Paulo

    2012-01-10

    The present study aimed determines lead (Pb), antimony (Sb) and barium (Ba) as the major elements present in GSR in the environmental air of the Ballistics Laboratory of the São Paulo Criminalistics Institute (I.C.-S.P.), São Paulo, SP, Brazil. Micro environmental monitors (mini samplers) were located at selected places. The PM(2.5) fraction of this airborne was collected in, previously weighted filters, and analyzed by sector field inductively coupled plasma mass spectrometer (SF-HR-ICP-MS). The higher values of the airborne lead, antimony and barium, were found at the firing range (lead (Pb): 58.9 μg/m(3); barium (Ba): 6.9 μg/m(3); antimony (Sb): 7.3 μg/m(3)). The mean value of the airborne in this room during 6 monitored days was Pb: 23.1 μg/m(3); Ba: 2.2 μg/m(3); Sb: 1.5 μg/m(3). In the water tank room, the air did not show levels above the limits of concern. In general the airborne lead changed from day to day, but the barium and antimony remained constant. Despite of that, the obtained values suggest that the workers may be exposed to airborne lead concentration that can result in an unhealthy environment and could increase the risk of chronic intoxication. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. Airborne In-Situ Measurements of Formaldehyde over California: First Results from the COFFEE Instrument

    Marrero, Josette; St. Clair, Jason; Yates, Emma; Swanson, Andrew; Gore, Warren; Iraci, Laura; Hanisco, Thomas

    2016-04-01

    Formaldehyde (HCHO) is one of the most abundant oxygenated volatile organic compounds (VOCs) in the atmosphere, playing a role multiple atmospheric processes. Measurements of HCHO can be used to help quantify convective transport, the abundance of VOCs, and ozone production in urban environments. The Compact Formaldehyde FluorescencE Experiment (COFFEE) instrument uses Non-Resonant Laser Induced Fluorescence (NR-LIF) to detect trace concentrations of HCHO as part of the Alpha Jet Atmospheric eXperiment (AJAX) payload. Developed at NASA GSFC, COFFEE is a small, low maintenance instrument with a sensitivity of 100 pptv and a quick response time (1 sec). The COFFEE instrument has been customized to fit in an external wing pod on the Alpha Jet aircraft based at NASA ARC. The instrument can operate over a broad range of altitudes, from boundary layer to lower stratosphere, making it well suited for the Alpha Jet, which can access altitudes from the surface up to 40,000 ft. We will present results from flights performed over the Central Valley of California, including boundary layer measurements and vertical profiles in the tropospheric column. This region is of particular interest, due to its elevated levels of HCHO, revealed in satellite images, as well as its high ozone concentrations. In addition to HCHO, the AJAX payload includes measurements of atmospheric ozone, methane, and carbon dioxide. These results will be presented in conjunction with formaldehyde. Targets in the Central Valley consist of an oil field, agricultural areas, and highways, each of which can emit HCHO primarily and generate HCHO through secondary production. Formaldehyde is one of the few urban pollutants that can be measured from space. Plans to compare in-situ COFFEE data with satellite-based HCHO observations such as those from OMI (Aura) and OMPS (SuomiNPP) will also be presented.

  7. Development of snow water equivalent survey methods using airborne gamma measurements. Research progress, January 1975--September 1975 and suggested directions for future work

    Fritzsche, A.; Jupiter, C.

    1975-01-01

    This is a summary of the progress made during the period March 1975 through September 1975 on EG and G's support of the National Oceanic and Atmospheric Administration for development of airborne techniques for measurement of the water equivalent of snow and soil moisture. The work included a series of snow and soil moisture surveys and development of a new detector and data acquisition system. The status of this work is summarized here together with a review of plans for the immediate future

  8. Airborne measurements of CO2 column concentrations made with a pulsed IPDA lidar using a multiple-wavelength-locked laser and HgCdTe APD detector

    Abshire, James B.; Ramanathan, Anand K.; Riris, Haris; Allan, Graham R.; Sun, Xiaoli; Hasselbrack, William E.; Mao, Jianping; Wu, Stewart; Chen, Jeffrey; Numata, Kenji; Kawa, Stephan R.; Yang, Mei Ying Melissa; DiGangi, Joshua

    2018-04-01

    Here we report on measurements made with an improved CO2 Sounder lidar during the ASCENDS 2014 and 2016 airborne campaigns. The changes made to the 2011 version of the lidar included incorporating a rapidly wavelength-tunable, step-locked seed laser in the transmitter, using a much more sensitive HgCdTe APD detector and using an analog digitizer with faster readout time in the receiver. We also improved the lidar's calibration approach and the XCO2 retrieval algorithm. The 2014 and 2016 flights were made over several types of topographic surfaces from 3 to 12 km aircraft altitudes in the continental US. The results are compared to the XCO2 values computed from an airborne in situ sensor during spiral-down maneuvers. The 2014 results show significantly better performance and include measurement of horizontal gradients in XCO2 made over the Midwestern US that agree with chemistry transport models. The results from the 2016 airborne lidar retrievals show precisions of ˜ 0.7 parts per million (ppm) with 1 s averaging over desert surfaces, which is an improvement of about 8 times compared to similar measurements made in 2011. Measurements in 2016 were also made over fresh snow surfaces that have lower surface reflectance at the laser wavelengths. The results from both campaigns showed that the mean values of XCO2 retrieved from the lidar consistently agreed with those based on the in situ sensor to within 1 ppm. The improved precision and accuracy demonstrated in the 2014 and 2016 flights should benefit future airborne science campaigns and advance the technique's readiness for a space-based instrument.

  9. The De-Icing Comparison Experiment (D-ICE): A campaign for improving data retention rates of radiometric measurements under icing conditions in cold regions

    Cox, C. J.; Morris, S. M.

    2017-12-01

    Longwave and shortwave radiative fluxes are fundamental quantities regularly observed globally using broadband radiometers. In cold climates, frost, rime, snow and ice (collectively, "icing") frequently builds up on sensor windows, contaminating measurements. Since icing occurs under particular meteorological conditions, associated data losses constitutes a climatological bias. Furthermore, the signal caused by ice is difficult to distinguish from that of clouds, hampering efforts to identify contaminated from real data in post-processing. Because of the sensitivity of radiometers to internal temperature instabilities, there are limitations to using heat as a de-icing method. The magnitude of this problem is indicated by the large number of research institutions and commercial vendors that have developed various de-icing strategies. The D-ICE campaign has been designed to bring together a large number of currently available systems to quantitatively evaluate and compare ice-migration strategies and also to characterize the potentially adverse effects of the techniques themselves. For D-ICE, a variety of automated approaches making use of ventilation, heating, modified housings and alcohol spray are being evaluated alongside standard units operating with only the regularly scheduled manual cleaning by human operators at the NOAA Baseline Surface Radiation Network (BSRN) station in Utqiaġvik (formerly Barrow), Alaska. Previous experience within the BSRN community suggests that aspiration of ambient air alone may be sufficient to maintain ice-free radiometers without increasing measurement uncertainty during icing conditions, forming the main guiding hypothesis of the experiment. Icing on the sensors is monitored visually using cameras recording images every 15 minutes and quantitatively using an icing probe and met station. The effects of applied heat on infrared loss in pyranometers will be analyzed and the integrated effect of icing on monthly averages will be

  10. Measuring landscape-scale spread and persistence of an invaded submerged plant community from airborne remote sensing.

    Santos, Maria J; Khanna, Shruti; Hestir, Erin L; Greenberg, Jonathan A; Ustin, Susan L

    2016-09-01

    Processes of spread and patterns of persistence of invasive species affect species and communities in the new environment. Predicting future rates of spread is of great interest for timely management decisions, but this depends on models that rely on understanding the processes of invasion and historic observations of spread and persistence. Unfortunately, the rates of spread and patterns of persistence are difficult to model or directly observe, especially when multiple rates of spread and diverse persistence patterns may be co-occurring over the geographic distribution of the invaded ecosystem. Remote sensing systematically acquires data over large areas at fine spatial and spectral resolutions over multiple time periods that can be used to quantify spread processes and persistence patterns. We used airborne imaging spectroscopy data acquired once a year for 5 years from 2004 to 2008 to map an invaded submerged aquatic vegetation (SAV) community across 2220 km 2 of waterways in the Sacramento-San Joaquin River Delta, California, USA, and measured its spread rate and its persistence. Submerged aquatic vegetation covered 13-23 km 2 of the waterways (6-11%) every year. Yearly new growth accounted for 40-60% of the SAV area, ~50% of which survived to following year. Spread rates were overall negative and persistence decreased with time. From this dataset, we were able to identify both radial and saltatorial spread of the invaded SAV in the entire extent of the Delta over time. With both decreasing spread rate and persistence, it is possible that over time the invasion of this SAV community could decrease its ecological impact. A landscape-scale approach allows measurements of all invasion fronts and the spatial anisotropies associated with spread processes and persistence patterns, without spatial interpolation, at locations both proximate and distant to the focus of invasion at multiple points in time. © 2016 by the Ecological Society of America.

  11. Composition and Morphology of Major Particle Types from Airborne Measurements during ICE-T and PRADACS Field Studies

    Venero, I. M.; Mayol-Bracero, O. L.; Anderson, J. R.

    2012-12-01

    As part of the Puerto Rican African Dust and Cloud Study (PRADACS) and the Ice in Clouds Experiment - Tropical (ICE-T), we sampled giant airborne particles to study their elemental composition, morphology, and size distributions. Samples were collected in July 2011 during field measurements performed by NCAR's C-130 aircraft based on St Croix, U.S Virgin Island. The results presented here correspond to the measurements done during research flight #8 (RF8). Aerosol particles with Dp > 1 um were sampled with the Giant Nuclei Impactor and particles with Dp 4000 ft) showed the highest concentrations of clay material. HYSPLIT back trajectories for all samples showed that the low altitude samples initiated in the free troposphere in the Atlantic Ocean, which may account for the high sea salt content and that the source of the high altitude samples was closer to the Saharan - Sahel desert region and, therefore, these samples possibly had the influence of African dust. Size distribution results for quartz and unreacted sea-salt aerosols collected on the Giant Nuclei Impactor showed that sample RF08 - 12:05 UTM (300 ft) had the largest size value (mean = 2.936 μm) than all the other samples. Additional information was also obtained from the Wyoming Inlet present at the C - 130 aircraft which showed that size distribution results for all particles were smaller in size. The different mineral components of the dust have different size distributions so that a fractionation process could occur during transport. Also, the presence of supermicron sea salt at altitude is important for cloud processes.

  12. Topography and Penetration of the Greenland Ice Sheet Measured with Airborne SAR Interferometry

    Dall, Jørgen; Madsen, Søren Nørvang; Keller, K.

    2001-01-01

    . The accuracy of the SAR DEM is about 1.5 m. The mean difference between the laser heights and the SAR heights changes from 0 m in the soaked zone to a maximum of 13 m in the percolation zone. This is explained by the fact that the snow in the soaked zone contains liquid water which attenuates the radar signals......, while the transparency of the firn in the percolation zone makes volume scattering dominate at the higher elevations. For the first time, the effective penetration has been measured directly as the difference between the interferometric heights and reference heights obtained with GPS and laser altimetry....

  13. Automated radiometric detection of bacteria

    Waters, J.R.

    1974-01-01

    A new radiometric method called BACTEC, used for the detection of bacteria in cultures or in supposedly sterile samples, was discussed from the standpoint of methodology, both automated and semi-automated. Some of the results obtained so far were reported and some future applications and development possibilities were described. In this new method, the test sample is incubated in a sealed vial with a liquid culture medium containing a 14 C-labeled substrate. If bacteria are present, they break down the substrate, producing 14 CO 2 which is periodically extracted from the vial as a gas and is tested for radioactivity. If this gaseous radioactivity exceeds a threshold level, it is evidence of bacterial presence and growth in the test vial. The first application was for the detection of bacteria in the blood cultures of hospital patients. Data were presented showing typical results. Also discussed were future applications, such as rapid screening for bacteria in urine industrial sterility testing and the disposal of used 14 C substrates. (Mukohata, S.)

  14. Radiometric-microbiologic assay fo vitamin B-6: analysis of plasma samples

    Guilarte, T.R.; McIntyre, P.A.

    1981-01-01

    A radiometric microbiologic assay for the analysis of vitamin B-6 in plasma was developed. The method is based on the measurement of 14CO2 generated from the metabolism of DL-l-14C-valine (L-l-14C-valine) by Kloeckera brevis. The assay is specific for the biologically active forms of the vitamin, that is, pyridoxine, pyridoxal and pyridoxamine, and their respective phosphorylated forms. The biologically inert vitamin B-6 metabolite (4-pyridoxic acid) did not generate a response at concentrations tested. The radiometric technique was shown to be sensitive to the 1 nanogram level. Reproducibility and recovery studies gave good results. Fifteen plasma samples were assayed using the radiometric and turbidimetric techniques. The correlation coefficient was r . 0.98. Turbid material or precipitated debris did not interfere with the radiometric microbiologic assay, thus allowing for simplification of assay procedure

  15. Predicting personal exposure to airborne carbonyls using residential measurements and time/activity data

    Liu, Weili; Zhang, Junfeng (Jim); Korn, Leo R.; Zhang, Lin; Weisel, Clifford P.; Turpin, Barbara; Morandi, Maria; Stock, Tom; Colome, Steve

    As a part of the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study, 48 h integrated residential indoor, outdoor, and personal exposure concentrations of 10 carbonyls were simultaneously measured in 234 homes selected from three US cities using the Passive Aldehydes and Ketones Samplers (PAKS). In this paper, we examine the feasibility of using residential indoor concentrations to predict personal exposures to carbonyls. Based on paired t-tests, the means of indoor concentrations were not different from those of personal exposure concentrations for eight out of the 10 measured carbonyls, indicating indoor carbonyls concentrations, in general, well predicted the central tendency of personal exposure concentrations. In a linear regression model, indoor concentrations explained 47%, 55%, and 65% of personal exposure variance for formaldehyde, acetaldehyde, and hexaldehyde, respectively. The predictability of indoor concentrations on cross-individual variability in personal exposure for the other carbonyls was poorer, explainingexposure concentrations. It was found that activities related to driving a vehicle and performing yard work had significant impacts on personal exposures to a few carbonyls.

  16. Airborne lidar measurements to investigate the impact of long-range transported dust on shallow marine trade wind convection

    Gross, S.; Gutleben, M.; Wirth, M.; Ewald, F.

    2017-12-01

    Aerosols and clouds are still main contributors to uncertainties in estimates and interpretation of the Earth's changing energy budget. Their interaction with the Earth's radiation budged has a direct component by scattering and absorbing solar and terrestrial radiation, and an indirect component, e.g. as aerosols modify the properties and thus the life-time of clouds or by changing the atmosphere's stability. Up to know now sufficient understanding in aerosol-cloud interaction and climate feedback is achieved. Thus studies with respect to clouds, aerosols, their interaction and influence on the radiation budged are highly demanded. In August 2016 the NARVAL-II (Next-generation airborne remote sensing for validation studies) mission took place. Measurements with a combined active (high spectral resolution and water vapor differential absorption lidar and cloud radar) and passive remote sensing (microwave radiometer, hyper spectral imager, radiation measurements) payload were performed with the German high altitude and long-range research aircraft HALO over the subtropical North-Atlantic Ocean to study shallow marine convection during the wet and dusty season. With this, NARVAL-II is follow-up of the NARVAL-I mission which took place during the dry and dust free season in December 2013. During NARVAL-II the measurement flights were designed the way to sample dust influenced areas as well as dust free areas in the trades. One main objective was to investigate the optical and macro physical properties of the dust layer, differences in cloud occurrence in dusty and non-dusty areas, and to study the influence of aerosols on the cloud properties and formation. This allows comparisons of cloud and aerosol distribution as well as their environment between the dry and the wet season, and of cloud properties and distribution with and without the influence of long-range transported dust across the Atlantic Ocean. In our presentation we will give an overview of the NARVAL

  17. Medidas radiométricas em casas de vegetação com cobertura plástica na região de Campinas - SP Radiometric measurement of greenhouses with plastic cover at Campinas region- SP

    Edilson Costa

    2011-06-01

    Full Text Available Com o objetivo de caracterizar as relações e alterações radiométricas em três casas de vegetação, cobertas com filme transparente de polietileno de baixa densidade (PEBD de camada simples com 150µm de espessura, tratado contra raios ultravioleta, sob ambientes distintos, foram realizados os experimentos durante o cultivo hidropônico de alface, cultivar Vera, na região de Campinas - SP, em diferentes períodos do ano, visando ao uso de dados experimentais de postos meteorológicos em substituição à necessidade de adquirir equipamentos de radiação para medições internas. As casas de vegetação eram de estrutura metálica de aço, de forma e volume idênticos. Coletaram-se a radiação solar global interna e externa (RSGI e RSGE, W m-2, a radiação fotossinteticamente ativa (RFA, µmol m-2 s-1 e a radiação ultravioleta, em 254; 312 e 365 nm (RUV, W m-2. Os resultados mostraram que as equações de regressão linear são estimativas aceitáveis na obtenção da radiação fotossinteticamente ativa em função da radiação solar global externa. Em ambientes fechados e climatizados, existe maior correlação entre a radiação fotossinteticamente ativa e a radiação solar global externa. A orientação das casas de vegetação não climatizadas não influencia no espalhamento interno da radiação fotossinteticamente ativa.The objective of this study was to characterize the radiometric relationship and changing in three greenhouses covered with transparent low density polyethylene film (PEBD with a 150µm single layer of low density polyethylene film, treated with compounds that inhibit rapid degradation by ultraviolet radiation, under effects of different environments. The experiments were conducted during hydroponics lettuce production of Vera variety at Campinas region-SP in different periods of the year, aiming the use of experimental data from meteorological stations in substitution of the needs to pursue radiometric

  18. Rural measurements of the chemical composition of airborne particles in the Eastern United States

    Wolff, G.T.; Kelly, N.A.; Ferman, M.A.; Morrissey, M.L.

    1983-01-01

    Quantitative measurements of particulate composition was made at three rural sites: in central South Dakota, on the Louisiana Gulf Coastal, and in the Blue Ridge Mountains of Virginia. The first two sites were selected to determine background concentrations in continental polar and maritime tropical air masses, respectively, which affect the eastern United State during the summer. The Virginia site was selected as a receptor site, downwind of the midwestern source area. The South Dakota data established the background concentrations. These concentrations were similar to the levels in Louisiana when air parcels arrived from the Gulf of Mexico, without recently passing over the United States. Levels of fine particles (diameters less than 2.5 μm) were highest in Virginia and were due chiefly to sulfate. Using trajectory and statistical analyses, it is shown that the residence time of an air parcel over the midwestern source area was the most important variable in determining the sulface levels in the Blue Ridge Mountains

  19. A review of measurement and characterisation of airborne long-lived alpha-emitting radionuclides

    Bigu, J.

    1993-01-01

    Sampling principles, monitoring instrumentation and characterisation of Long-Lived Radioactive Dust (LLRD) generated in U-Th mine and mill operations are discussed. Methods and techniques for the quantification, radionuclide identification and the study of other important characteristics of LLRD (e.g., electrical charge) are reviewed. Furthermore, field and laboratory measurements and methods of radiation dose assessment are revised. Some emphasis is placed in this work on occupational worker exposure assessment and the principles, methods and techniques of 'external' radiation exposure, internal dosimetry, and dosimetric models. It is clear that in spite of constant advances in the several areas which are the subject of this paper, there is still considerable room for improvement. For example, there is no universally accepted sampling protocol and sampler for routine LLRD monitoring for occupational hygiene exposure calculation purposes. Other areas for improvement could include calibration of instrumentation and improved sensitivity in radionuclide quantification and identification. 105 refs., 6 tabs., 3 figs

  20. Study of a new radiometric sterility test in radiopharmaceuticals

    Sanchez P, A.R.

    1976-01-01

    A new radiometric method is studied for the determination of sterility. It is based on a culture marked with carbon-14 and the measurement by liquid scintillation of the radioactivity of the gaseous products released after a short period of incubation. The studied samples consisted in nonradioactive solutions and different radiopharmaceuticals, through a regulated current of nitrogen there is a transportation of gaseous and volatile products produced in each flask, which were received in a liquid scintillation vial. The experimental data permit to conclude that through the radiometric method the results can be obtained after 24 hours or less of incubation, instead of a period of several days which was necessary with the traditional process. Due to the sensitivity of the method it is possible to inoculate a minimum volume of sample, this is important in the case of the preparation of little parts for injection as it occurs generally with the pharmaceuticals. (author)

  1. Radiometric and dosimetric characteristics of HgI2 detectors

    Zaletin, V.M.; Krivozubov, O.V.; Torlin, M.A.; Fomin, V.I.

    1988-01-01

    The characteristics of HgI 2 detectors in x-ray and gamma detection in applications to radiometric and dosimetric monitoring and as portable instruments for such purposes was considered. Blocks with mosaic and sandwich structures were prepared and tested against each other and, for comparative purposes, against CdTe detectors for relative sensitivities at various gamma-quanta energies. Sensitivity dependencies on gamma radiation energy were plotted for the detector materials and structures as were current dependencies on the dose rate of x rays. Results indicated that the mercury iodide detectors could be used in radiometric and dosimetric measurements at gamma quantum energies up to and in excess of 1000 KeV

  2. Airborne Measurements and Air Quality Impacts of the 2016 California Soberanes Wildfire

    Marrero, J. E.; Asher, E. C. C.; Yates, E. L.; St Clair, J. M.; Ryoo, J. M.; McNamara, M.; Hanisco, T. F.; Gore, W.; Faloona, I. C.; Iraci, L. T.

    2017-12-01

    Emissions from biomass burning are an important source of a multitude of trace gases and particles that contribute to local and regional air quality, climate forcing, and have human health impacts. Among the compounds emitted are greenhouse gases including carbon dioxide (CO2) and methane (CH4), organics such as formaldehyde (HCHO), and other harmful species including carbon monoxide (CO) and particulate matter (PM). In addition, biomass burning is a primary source of volatile organic compounds (VOCs) and nitrogen oxides (NOx = NO + NO2), contributing to formation of tropospheric ozone (O3) and reduced regional air quality. Emissions of the various ozone precursors in a fire differ based on vegetation (fuel) type, fire intensity, and age of the plume, complicating the prediction of O3 formation. The Soberanes Fire began from an illegal campfire on 22 July 2016 in the Garrapata State Park in Monterey County, California (36.460 °N, -121.900 °W). Over the following three months the fire burned a total of 132,127 acres. Presented here are aircraft measurements of CO2, CH4, O3, and HCHO from five flights near and downwind of the Soberanes wildfire, collected as part of the Alpha Jet Atmospheric eXperiment (AJAX). In situ data are used to determine emission ratios (ERs), or excess mixing ratio relative to CO2. In addition, measurements of NOx and O3 from a coastal mountaintop site are presented, and are used to estimate O3 production rates during the Soberanes Fire burning period. Lastly, the extent of ozone enhancement and air quality impacts downwind of the fire will be addressed using ground-based monitoring data, the NOAA Hazard Mapping System (HMS) smoke product and HYSPLIT trajectory model.

  3. Pulsed Lidar Measurements of Atmospheric CO2 Column Absorption and Range During the ASCENDS 2009-2011 Airborne Campaigns

    Abshire, J. B.; Weaver, C. J.; Riris, H.; Mao, J.; Sun, X.; Allan, G. R.; Hasselbrack, W. E.; Browell, E. V.

    2012-01-01

    We have developed a pulsed lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's ASCENDS mission and have demonstrated the CO2 and O2 measurements from aircraft. Our technique uses two pulsed lasers allowing simultaneous measurement of a single CO2 absorption line near 1572 nm, O2 extinction in the Oxygen A-band, surface height and backscatter profile. The lasers are stepped in wavelength across the CO2 line and an O2 line doublet during the measurement. The column densities for the CO2 and O2 are estimated from the differential optical depths (DOD) of the scanned absorption lines via the IPDA technique. For the 2009 ASCENDS campaign we flew the CO2 lidar only on a Lear-25 aircraft, and measured the absorption line shapes of the CO2 line using 20 wavelength samples per scan. Measurements were made at stepped altitudes from 3 to 12.6 km over the Lamont OK, central Illinois, North Carolina, and over the Virginia Eastern Shore. Although the received signal energies were weaker than expected for ASCENDS, clear C02 line shapes were observed at all altitudes. Most flights had 5-6 altitude steps with 200-300 seconds of recorded measurements per step. We averaged every 10 seconds of measurements and used a cross-correlation approach to estimate the range to the scattering surface and the echo pulse energy at each wavelength. We then solved for the best-fit CO2 absorption line shape, and calculated the DOD of the fitted CO2 line, and computed its statistics at the various altitude steps. We compared them to CO2 optical depths calculated from spectroscopy based on HITRAN 2008 and the column number densities calculated from the airborne in-situ readings. The 2009 measurements have been analyzed in detail and they were similar on all flights. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. They showed the expected nearly the linear dependence of DOD vs

  4. Prediction of topographic and bathymetric measurement performance of airborne low-SNR lidar systems

    Cossio, Tristan

    Low signal-to-noise ratio (LSNR) lidar (light detection and ranging) is an alternative paradigm to traditional lidar based on the detection of return signals at the single photoelectron level. The objective of this work was to predict low altitude (600 m) LSNR lidar system performance with regards to elevation measurement and target detection capability in topographic (dry land) and bathymetric (shallow water) scenarios. A modular numerical sensor model has been developed to provide data for further analysis due to the dearth of operational low altitude LSNR lidar systems. This simulator tool is described in detail, with consideration given to atmospheric effects, surface conditions, and the effects of laser phenomenology. Measurement performance analysis of the simulated topographic data showed results comparable to commercially available lidar systems, with a standard deviation of less than 12 cm for calculated elevation values. Bathymetric results, although dependent largely on water turbidity, were indicative of meter-scale horizontal data spacing for sea depths less than 5 m. The high prevalence of noise in LSNR lidar data introduces significant difficulties in data analysis. Novel algorithms to reduce noise are described, with particular focus on their integration into an end-to-end target detection classifier for both dry and submerged targets (cube blocks, 0.5 m to 1.0 m on a side). The key characteristic exploited to discriminate signal and noise is the temporal coherence of signal events versus the random distribution of noise events. Target detection performance over dry earth was observed to be robust, reliably detecting over 90% of targets with a minimal false alarm rate. Comparable results were observed in waters of high clarity, where the investigated system was generally able to detect more than 70% of targets to a depth of 5 m. The results of the study show that CATS, the University of Florida's LSNR lidar prototype, is capable of high fidelity

  5. Laboratory-Based BRDF Calibration of Radiometric Tarps

    Georgiev, Georgi T.; Butler, James J.

    2007-01-01

    The current study provides the remote sensing community with important high accuracy laboratory-based BRDF calibration of radiometric tarps. The results illustrate the dependence of tarps' weft and warp threads orientation on BRDF. The study was done at incident angles of 0deg, 10deg, and 30deg; scatter zenith angles from 0deg to 60deg, and scatter azimuth angles of 0deg, 45deg, 90deg, 135deg, and 180deg. The wavelengths were 485nm, 550nm, 633nm and 800nm. The dependence is well defined at all measurement geometries and wavelengths. It can be as high as 8% at 0deg incident angle and 2% at 30deg incident angle. The fitted BRDF data show a very small discrepancy from the measured ones. New data on the forward and backscatter properties of radiometric tarps is reported. The backward scatter is well pronounced for the white samples. The black sample has well pronounced forward scatter. The BRDF characterization of radiometric tarps can be successfully extended to other structured surface fabric samples. The results are NIST traceable.

  6. Airborne measurements of nucleation mode particles I: coastal nucleation and growth rates

    C. D. O'Dowd

    2007-01-01

    Full Text Available A light aircraft was equipped with a bank of Condensation Particle Counters (CPCs (50% cut from 3–5.4–9.6 nm and a nano-Scanning Mobility Particle Sizer (nSMPS and deployed along the west coast of Ireland, in the vicinity of Mace Head. The objective of the exercise was to provide high resolution micro-physical measurements of the coastal nucleation mode in order to map the spatial extent of new particle production regions and to evaluate the evolution, and associated growth rates of the coastal nucleation-mode aerosol plume. Results indicate that coastal new particle production is occurring over most areas along the land-sea interface with peak concentrations at the coastal plume-head in excess of 106 cm−3. Pseudo-Lagrangian studies of the coastal plume evolution illustrated significant growth of new particles to sizes in excess of 8 nm approximately 10 km downwind of the source region. Close to the plume head (<1 km growth rates can be as high as 123–171 nm h−1, decreasing gradually to 53–72 nm h−1 at 3 km. Further along the plume, at distances up to 10 km, the growth rates are calculated to be 17–32 nm h−1. Growth rates of this magnitude suggest that after a couple of hours, coastal nucleation mode particles can reach significant sizes where they can contribution to the regional aerosol loading.

  7. Airborne In-Situ Trace Gas Measurements of Multiple Wildfires in California (2013-2014)

    Iraci, L. T.; Yates, E. L.; Tanaka, T.; Roby, M.; Gore, W.; Clements, C. B.; Lareau, N.; Ambrosia, V. G.; Quayle, B.; Schroeder, W.

    2014-12-01

    Biomass burning emissions are an important source of a wide range of trace gases and particles that can impact local, regional and global air quality, climate forcing, biogeochemical cycles and human health. In the western US, wildfires dominate over prescribed fires, contributing to atmospheric trace gas budgets and regional and local air pollution. Limited sampling of emissions from wildfires means western US emission estimates rely largely on data from prescribed fires, which may not be a suitable proxy for wildfire emissions. We report here in-situ measurements of carbon dioxide, methane, ozone and water vapor from the plumes of a variety of wildfires sampled in California in the fire seasons of 2013 and 2014. Included in the analysis are the Rim Fire (August - October 2013, near Yosemite National Park), the Morgan Fire (September 2013, near Clayton, CA), and the El Portal Fire (July - August 2014, in Yosemite National Park), among others. When possible, fires were sampled on multiple days. Emission ratios and estimated emission factors will be presented and discussed in the context of fuel composition, plume structure, and fire phase. Correlations of plume chemical composition to MODIS/VIIRS Fire Radiative Power (FRP) and other remote sensing information will be explored. Furthermore, the role of plumes in delivery of enhanced ozone concentrations to downwind municipalities will be discussed.

  8. High-resolution measurements from the airborne Atmospheric Nitrogen Dioxide Imager (ANDI)

    Lawrence, J. P.; Anand, J. S.; Vande Hey, J. D.; White, J.; Leigh, R. R.; Monks, P. S.; Leigh, R. J.

    2015-11-01

    Nitrogen dioxide is both a primary pollutant with direct health effects and a key precursor of the secondary pollutant ozone. This paper reports on the development, characterisation and test flight of the Atmospheric Nitrogen Dioxide Imager (ANDI) remote sensing system. The ANDI system includes an imaging UV/Vis grating spectrometer able to capture scattered sunlight spectra for the determination of tropospheric nitrogen dioxide (NO2) concentrations by way of DOAS slant column density and vertical column density measurements. Results are shown for an ANDI test flight over Leicester City in the UK on a cloud-free winter day in February 2013. Retrieved NO2 columns gridded to a surface resolution of 80 m × 20 m revealed hotspots in a series of locations around Leicester City, including road junctions, the train station, major car parks, areas of heavy industry, a nearby airport (East Midlands) and a power station (Ratcliffe-on-Soar). In the city centre the dominant source of NO2 emissions was identified as road traffic, contributing to a background concentration as well as producing localised hotspots. Quantitative analysis revealed a significant urban increment over the city centre which increased throughout the flight.

  9. Pollutants transport and atmospheric variability of CO2 over Siberia: contribution of airborne measurements

    Paris, J.D.

    2008-12-01

    The work presented here intends to characterize the variations of atmospheric concentrations of CO 2 , CO, O 3 and ultrafine particles, over a large scale aircraft transect above Siberia, during three intensive YAK-AEROSIB campaigns in April 2006, September 2006 and August 2007, respectively. Pollutant and greenhouse gases distribution in this poorly studied region is needed to model atmospheric long range transport. I show here that CO concentrations at the time of the campaigns is broadly affected by (1) advection of Chinese pollutants through baro-clinic perturbations, (2) advection (diffuse or not) of European pollutants at various altitudes, (3) and of biomass burning from Central Asia. This set of factors is analyzed through a novel statistical technique based on clustering of backward transport simulated by the FLEXPART Lagrangian model. Large observed CO 2 gradients in summer are matched against vertical mixing in GCM simulated CO 2 . At last I present ultrafine particle measurements, and a possible nucleation summer maximum in the clean, continental mid-troposphere. (author)

  10. Conditional-sampling spectrograph detection system for fluorescence measurements of individual airborne biological particles

    Nachman, Paul; Pinnick, R. G.; Hill, Steven C.; Chen, Gang; Chang, Richard K.; Mayo, Michael W.; Fernandez, Gilbert L.

    1996-03-01

    We report the design and operation of a prototype conditional-sampling spectrograph detection system that can record the fluorescence spectra of individual, micrometer-sized aerosols as they traverse an intense 488-nm intracavity laser beam. The instrument's image-intensified CCD detector is gated by elastic scattering or by undispersed fluorescence from particles that enter the spectrograph's field of view. It records spectra only from particles with preselected scattering-fluorescence levels (a fiber-optic-photomultiplier subsystem provides the gating signal). This conditional-sampling procedure reduces data-handling rates and increases the signal-to-noise ratio by restricting the system's exposures to brief periods when aerosols traverse the beam. We demonstrate these advantages by reliably capturing spectra from individual fluorescent microspheres dispersed in an airstream. The conditional-sampling procedure also permits some discrimination among different types of particles, so that spectra may be recorded from the few interesting particles present in a cloud of background aerosol. We demonstrate such discrimination by measuring spectra from selected fluorescent microspheres in a mixture of two types of microspheres, and from bacterial spores in a mixture of spores and nonfluorescent kaolin particles.

  11. Methane emissions from a Californian landfill, determined from airborne remote sensing and in situ measurements

    S. Krautwurst

    2017-09-01

    Full Text Available Fugitive emissions from waste disposal sites are important anthropogenic sources of the greenhouse gas methane (CH4. As a result of the growing world population and the recognition of the need to control greenhouse gas emissions, this anthropogenic source of CH4 has received much recent attention. However, the accurate assessment of the CH4 emissions from landfills by modeling and existing measurement techniques is challenging. This is because of inaccurate knowledge of the model parameters and the extent of and limited accessibility to landfill sites. This results in a large uncertainty in our knowledge of the emissions of CH4 from landfills and waste management. In this study, we present results derived from data collected during the research campaign COMEX (CO2 and MEthane eXperiment in late summer 2014 in the Los Angeles (LA Basin. One objective of COMEX, which comprised aircraft observations of methane by the remote sensing Methane Airborne MAPper (MAMAP instrument and a Picarro greenhouse gas in situ analyzer, was the quantitative investigation of CH4 emissions. Enhanced CH4 concentrations or CH4 plumes were detected downwind of landfills by remote sensing aircraft surveys. Subsequent to each remote sensing survey, the detected plume was sampled within the atmospheric boundary layer by in situ measurements of atmospheric parameters such as wind information and dry gas mixing ratios of CH4 and carbon dioxide (CO2 from the same aircraft. This was undertaken to facilitate the independent estimation of the surface fluxes for the validation of the remote sensing estimates. During the COMEX campaign, four landfills in the LA Basin were surveyed. One landfill repeatedly showed a clear emission plume. This landfill, the Olinda Alpha Landfill, was investigated on 4 days during the last week of August and first days of September 2014. Emissions were estimated for all days using a mass balance approach. The derived emissions vary between 11

  12. Experiences with radiometric solid matter determination in the WOLPRYLA-65 fibre production

    Butz, M.; Traeber, K.

    1977-01-01

    Proceeding from the technology of WOLPRYLA-65 fibre fabrication the applicability of radiometric density measurements for acrylonitrile determination in a dimethylformamide bath has been studied. The measuring equipment and measuring positions are described and further details, such as calibration procedures, measuring accuracy, benefit of continuous and contactless measurements, maintenance efforts, and radiation protection measures are outlined

  13. Evaluation of the reactive nitrogen budget of the remote atmosphere in global models using airborne measurements

    Murray, L. T.; Strode, S. A.; Fiore, A. M.; Lamarque, J. F.; Prather, M. J.; Thompson, C. R.; Peischl, J.; Ryerson, T. B.; Allen, H.; Blake, D. R.; Crounse, J. D.; Brune, W. H.; Elkins, J. W.; Hall, S. R.; Hintsa, E. J.; Huey, L. G.; Kim, M. J.; Moore, F. L.; Ullmann, K.; Wennberg, P. O.; Wofsy, S. C.

    2017-12-01

    Nitrogen oxides (NOx ≡ NO + NO2) in the background atmosphere are critical precursors for the formation of tropospheric ozone and OH, thereby exerting strong influence on surface air quality, reactive greenhouse gases, and ecosystem health. The impact of NOx on atmospheric composition and climate is sensitive to the relative partitioning of reactive nitrogen between NOx and longer-lived reservoir species of the total reactive nitrogen family (NOy) such as HNO3, HNO4, PAN and organic nitrates (RONO2). Unfortunately, global chemistry-climate models (CCMs) and chemistry-transport models (CTMs) have historically disagreed in their reactive nitrogen budgets outside of polluted continental regions, and we have lacked in situ observations with which to evaluate them. Here, we compare and evaluate the NOy budget of six global models (GEOS-Chem CTM, GFDL AM3 CCM, GISS E2.1 CCM, GMI CTM, NCAR CAM CCM, and UCI CTM) using new observations of total reactive nitrogen and its member species from the NASA Atmospheric Tomography (ATom) mission. ATom has now completed two of its four planned deployments sampling the remote Pacific and Atlantic basins of both hemispheres with a comprehensive suite of measurements for constraining reactive photochemistry. All six models have simulated conditions climatologically similar to the deployments. The GMI and GEOS-Chem CTMs have in addition performed hindcast simulations using the MERRA-2 reanalysis, and have been sampled along the flight tracks. We evaluate the performance of the models relative to the observations, and identify factors contributing to their disparate behavior using known differences in model oxidation mechanisms, heterogeneous loss pathways, lightning and surface emissions, and physical loss processes.

  14. Techniques for Estimating Emissions Factors from Forest Burning: ARCTAS and SEAC4RS Airborne Measurements Indicate which Fires Produce Ozone

    Chatfield, Robert B.; Andreae, Meinrat O.

    2016-01-01

    Previous studies of emission factors from biomass burning are prone to large errors since they ignore the interplay of mixing and varying pre-fire background CO2 levels. Such complications severely affected our studies of 446 forest fire plume samples measured in the Western US by the science teams of NASA's SEAC4RS and ARCTAS airborne missions. Consequently we propose a Mixed Effects Regression Emission Technique (MERET) to check techniques like the Normalized Emission Ratio Method (NERM), where use of sequential observations cannot disentangle emissions and mixing. We also evaluate a simpler "consensus" technique. All techniques relate emissions to fuel burned using C(burn) = delta C(tot) added to the fire plume, where C(tot) approximately equals (CO2 = CO). Mixed-effects regression can estimate pre-fire background values of C(tot) (indexed by observation j) simultaneously with emissions factors indexed by individual species i, delta, epsilon lambda tau alpha-x(sub I)/C(sub burn))I,j. MERET and "consensus" require more than emissions indicators. Our studies excluded samples where exogenous CO or CH4 might have been fed into a fire plume, mimicking emission. We sought to let the data on 13 gases and particulate properties suggest clusters of variables and plume types, using non-negative matrix factorization (NMF). While samples were mixtures, the NMF unmixing suggested purer burn types. Particulate properties (b scant, b abs, SSA, AAE) and gas-phase emissions were interrelated. Finally, we sought a simple categorization useful for modeling ozone production in plumes. Two kinds of fires produced high ozone: those with large fuel nitrogen as evidenced by remnant CH3CN in the plumes, and also those from very intense large burns. Fire types with optimal ratios of delta-NOy/delta- HCHO associate with the highest additional ozone per unit Cburn, Perhaps these plumes exhibit limited NOx binding to reactive organics. Perhaps these plumes exhibit limited NOx binding to

  15. The carbon debt from Amazon forest degradation: integrating airborne lidar, field measurements, and an ecosystem demography model.

    Longo, M.; Keller, M. M.; dos-Santos, M. N.; Scaranello, M. A., Sr.; Pinagé, E. R.; Leitold, V.; Morton, D. C.

    2016-12-01

    Amazon deforestation has declined over the last decade, yet forest degradation from logging, fire, and fragmentation continue to impact forest carbon stocks and fluxes. The magnitude of this impact remains uncertain, and observation-based studies are often limited by short time intervals or small study areas. To better understand the long-term impact of forest degradation and recovery, we have been developing a framework that integrates field plot measurements and airborne lidar surveys into an individual- and process-based model (Ecosystem Demography model, ED). We modeled forest dynamics for three forest landscapes in the Amazon with diverse degradation histories: conventional and reduced-impact logging, logging and burning, and multiple burns. Based on the initialization with contemporary forest structure and composition, model results suggest that degraded forests rapidly recover (30 years) water and energy fluxes compared with old-growth, even at sites that were affected by multiple fires. However, degraded forests maintained different carbon stocks and fluxes even after 100 years without further disturbances, because of persistent differences in forest structure and composition. Recurrent disturbances may hinder the recovery of degraded forests. Simulations using a simple fire model entirely dependent on environmental controls indicate that the most degraded forests would take much longer to reach biomass typical of old-growth forests, because drier conditions near the ground make subsequent fires more intense and more recurrent. Fires in tropical forests are also closely related to nearby human activities; while results suggest an important feedback between fires and the microenvironment, additional work is needed to improve how the model represents the human impact on current and future fire regimes. Our study highlights that recovery of degraded forests may act as an important carbon sink, but efficient recovery depends on controlling future disturbances.

  16. Elemental properties of copper slag and measured airborne exposures at a copper slag processing facility.

    Mugford, Christopher; Gibbs, Jenna L; Boylstein, Randy

    2017-08-01

    measures are not taken. To our knowledge, this is the first attempt to characterize exposures associated with copper slag processing. More in-depth air monitoring and health surveillance is needed to understand occupational exposures and health outcomes in this industry.

  17. Radiometric assays for the measurement of PSA

    Venkatesh, M.

    1997-01-01

    Prostate Specific Antigen, a serine protease enzyme, of M.W. ∼ 26-33 kDa, is widely considered to be a very useful marker for prostate cancer. It satisfies nearly all the requirements of an ideal 'Tumour Marker' and has hence attracted a lot of attention in the past decade. PSA is present in multiple forms in serum, with an appreciable fraction bound to the protease inhibitor α-1-antichymotrypsin (ACT) and to a small extent to other proteins such as α-2-macroglobulin (AMG) leaving the rest in the free form. The total PSA levels have been reported to have 80% sensitivity and 60% specificity towards the detection of prostate cancer. The lack of specificity occurs mainly due to the high levels of t-PSA in benign prostatic hypertrophy(BPH) apart from the cancer. The concept of free PSA has been introduced in the recent past and the ratio of free/total PSA levels have been shown to be advantageous in the differential diagnosis of BPH from prostate cancer. The f/t ratio is considered to be particularly useful in the grey zones of decision making (t-PSA levels 4-20 ng/mL). The need for the development of assays for total and free PSA is felt due to: a. the high incidence of prostate cancers being detected currently; b. the high cost of tests (higher for free PSA assay, and the cost becomes an important parameter when a patient has to be regularly monitored after therapy) that is not affordable for many patients; c. the potential for research in the area of prostate cancer management where the PSA (total and free) assays will be of great help

  18. ANALYZING SPECTRAL CHARACTERISTICS OF SHADOW AREA FROM ADS-40 HIGH RADIOMETRIC RESOLUTION AERIAL IMAGES

    Y.-T. Hsieh

    2016-06-01

    Full Text Available The shadows in optical remote sensing images are regarded as image nuisances in numerous applications. The classification and interpretation of shadow area in a remote sensing image are a challenge, because of the reduction or total loss of spectral information in those areas. In recent years, airborne multispectral aerial image devices have been developed 12-bit or higher radiometric resolution data, including Leica ADS-40, Intergraph DMC. The increased radiometric resolution of digital imagery provides more radiometric details of potential use in classification or interpretation of land cover of shadow areas. Therefore, the objectives of this study are to analyze the spectral properties of the land cover in the shadow areas by ADS-40 high radiometric resolution aerial images, and to investigate the spectral and vegetation index differences between the various shadow and non-shadow land covers. According to research findings of spectral analysis of ADS-40 image: (i The DN values in shadow area are much lower than in nonshadow area; (ii DN values received from shadowed areas that will also be affected by different land cover, and it shows the possibility of land cover property retrieval as in nonshadow area; (iii The DN values received from shadowed regions decrease in the visible band from short to long wavelengths due to scattering; (iv The shadow area NIR of vegetation category also shows a strong reflection; (v Generally, vegetation indexes (NDVI still have utility to classify the vegetation and non-vegetation in shadow area. The spectral data of high radiometric resolution images (ADS-40 is potential for the extract land cover information of shadow areas.

  19. Transportable high sensitivity small sample radiometric calorimeter

    Wetzel, J.R.; Biddle, R.S.; Cordova, B.S.; Sampson, T.E.; Dye, H.R.; McDow, J.G.

    1998-01-01

    A new small-sample, high-sensitivity transportable radiometric calorimeter, which can be operated in different modes, contains an electrical calibration method, and can be used to develop secondary standards, will be described in this presentation. The data taken from preliminary tests will be presented to indicate the precision and accuracy of the instrument. The calorimeter and temperature-controlled bath, at present, require only a 30-in. by 20-in. tabletop area. The calorimeter is operated from a laptop computer system using unique measurement module capable of monitoring all necessary calorimeter signals. The calorimeter can be operated in the normal calorimeter equilibration mode, as a comparison instrument, using twin chambers and an external electrical calibration method. The sample chamber is 0.75 in (1.9 cm) in diameter by 2.5 in. (6.35 cm) long. This size will accommodate most 238 Pu heat standards manufactured in the past. The power range runs from 0.001 W to <20 W. The high end is only limited by sample size

  20. Passive remote sensing of large-scale methane emissions from Oil Fields in California's San Joaquin Valley and validation by airborne in-situ measurements - Results from COMEX

    Gerilowski, Konstantin; Krautwurst, Sven; Thompson, David R.; Thorpe, Andrew K.; Kolyer, Richard W.; Jonsson, Haflidi; Krings, Thomas; Frankenberg, Christian; Horstjann, Markus; Leifer, Ira; Eastwood, Michael; Green, Robert O.; Vigil, Sam; Fladeland, Matthew; Schüttemeyer, Dirk; Burrows, John P.; Bovensmann, Heinrich

    2016-04-01

    The CO2 and MEthane EXperiment (COMEX) was a NASA and ESA funded campaign in support of the HyspIRI and CarbonSat mission definition activities. As a part of this effort, seven flights were performed between June 3 and September 4, 2014 with the Methane Airborne MAPper (MAMAP) remote sensing instrument (operated by the University of Bremen in cooperation with the German Research Centre for Geosciences - GFZ) over the Kern River, Kern Front, and Poso Creek Oil Fields located in California's San Joaquin Valley. MAMAP was installed for the flights aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft, together with: a Picarro fast in-situ greenhouse gas (GHG) analyzer operated by the NASA Ames Research Center, ARC; a 5-hole turbulence probe; and an atmospheric measurement package operated by CIRPAS measuring aerosols, temperature, dew-point, and other atmospheric parameters. Three of the flights were accompanied by the Next Generation Airborne Visual InfraRed Imaging Spectrometer (AVIRIS-NG), operated by the Jet Propulsion Laboratory (JPL), California Institute of Technology, installed aboard a second Twin Otter aircraft. Large-scale, high-concentration CH4 plumes were detected by the MAMAP instrument over the fields and tracked over several kilometers. The spatial distribution of the MAMAP observed plumes was compared to high spatial resolution CH4 anomaly maps derived by AVIRIS-NG imaging spectroscopy data. Remote sensing data collected by MAMAP was used to infer CH4 emission rates and their distributions over the three fields. Aggregated emission estimates for the three fields were compared to aggregated emissions inferred by subsequent airborne in-situ validation measurements collected by the Picarro instrument. Comparison of remote sensing and in-situ flux estimates will be presented, demonstrating the ability of airborne remote sensing data to provide accurate emission estimates for concentrations above the

  1. Airborne measurements of aerosol optical properties related to early spring transport of mid-latitude sources into the Arctic

    R. A. de Villiers

    2010-06-01

    Full Text Available Airborne lidar and in-situ measurements of the aerosol properties were conducted between Svalbard Island and Scandinavia in April 2008. Evidence of aerosol transport from Europe and Asia is given. The analysis of the aerosol optical properties based on a multiwavelength lidar (355, 532, 1064 nm including volume depolarization at 355 nm aims at distinguishing the role of the different aerosol sources (Siberian wild fires, Eastern Asia and European anthropogenic emissions. Combining, first aircraft measurements, second FLEXPART simulations with a calculation of the PBL air fraction originating from the three different mid-latitude source regions, and third level-2 CALIPSO data products (i.e. backscatter coefficient 532 nm,volume depolarization and color ratio between 1064 and 532 nm in aerosol layers along the transport pathways, appears a valuable approach to identify the role of the different aerosol sources even after a transport time larger than 4 days. Optical depth of the aerosol layers are always rather small (<4% while transported over the Arctic and ratio of the total attenuated backscatter (i.e. including molecular contribution provide more stable result than conventional aerosol backscatter ratio. Above Asia, CALIPSO data indicate more depolarization (up to 15% and largest color ratio (>0.5 for the northeastern Asia emissions (i.e. an expected mixture of Asian pollution and dust, while low depolarization together with smaller and quasi constant color ratio (≈0.3 are observed for the Siberian biomass burning emissions. A similar difference is visible between two layers observed by the aircraft above Scandinavia. The analysis of the time evolution of the aerosol optical properties revealed by CALIPSO between Asia and Scandinavia shows a gradual decrease of the aerosol backscatter, depolarization ratio and color ratio which suggests the removal of the largest particles in the accumulation mode. A similar study conducted for a European

  2. Enhancement of the aerosol direct radiative effect by semi-volatile aerosol components: airborne measurements in North-Western Europe

    W. T. Morgan

    2010-09-01

    Full Text Available A case study of atmospheric aerosol measurements exploring the impact of the vertical distribution of aerosol chemical composition upon the radiative budget in North-Western Europe is presented. Sub-micron aerosol chemical composition was measured by an Aerodyne Aerosol Mass Spectrometer (AMS on both an airborne platform and a ground-based site at Cabauw in the Netherlands. The examined period in May 2008 was characterised by enhanced pollution loadings in North-Western Europe and was dominated by ammonium nitrate and Organic Matter (OM. Both ammonium nitrate and OM were observed to increase with altitude in the atmospheric boundary layer. This is primarily attributed to partitioning of semi-volatile gas phase species to the particle phase at reduced temperature and enhanced relative humidity. Increased ammonium nitrate concentrations in particular were found to strongly increase the ambient scattering potential of the aerosol burden, which was a consequence of the large amount of associated water as well as the enhanced mass. During particularly polluted conditions, increases in aerosol optical depth of 50–100% were estimated to occur due to the observed increase in secondary aerosol mass and associated water uptake. Furthermore, the single scattering albedo was also shown to increase with height in the boundary layer. These enhancements combined to increase the negative direct aerosol radiative forcing by close to a factor of two at the median percentile level. Such increases have major ramifications for regional climate predictions as semi-volatile components are often not included in aerosol models.

    The results presented here provide an ideal opportunity to test regional and global representations of both the aerosol vertical distribution and subsequent impacts in North-Western Europe. North-Western Europe can be viewed as an analogue for the possible future air quality over other polluted regions of the Northern Hemisphere, where

  3. Airborne Measurements and Emission Estimates of Greenhouse Gases and Other Trace Constituents From the 2013 California Yosemite Rim Wildfire

    Yates, E. L.; Iraci, L. T.; Singh, H. B.; Tanaka, T.; Roby, M. C.; Hamill, P.; Clements, C. B.; Lareau, N.; Contezac, J.; Blake, D. R.; hide

    2015-01-01

    This paper presents airborne measurements of multiple atmospheric trace constituents including greenhouse gases (such as CO2, CH4, O3) and biomass burning tracers (such as CO, CH3CN) downwind of an exceptionally large wildfire. In summer 2013, the Rim wildfire, ignited just west of the Yosemite National Park, California, and burned over 250,000 acres of the forest during the 2-month period (17 August to 24 October) before it was extinguished. The Rim wildfire plume was intercepted by flights carried out by the NASA Ames Alpha Jet Atmospheric eXperiment (AJAX) on 29 August and the NASA DC-8, as part of SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys), on 26 and 27 August during its intense, primary burning period. AJAX revisited the wildfire on 10 September when the conditions were increasingly smoldering, with slower growth. The more extensive payload of the DC-8 helped to bridge key measurements that were not available as part of AJAX (e. g. CO). Data analyses are presented in terms of emission ratios (ER), emission factors (EF) and combustion efficiency and are compared with previous wildfire studies. ERs were 8.0 ppb CH4/(ppm CO2) on 26 August, 6.5 ppb CH4 (ppm CO2)1 on 29 August and 18.3 ppb CH4 (ppm CO2)1 on 10 September 2013. The increase in CH4 ER from 6.5 to 8.0 ppb CH4/(ppm CO2) during the primary burning period to 18.3 ppb CH4/(ppm CO2) during the fire's slower growth period likely indicates enhanced CH4 emissions from increased smoldering combustion relative to flaming combustion. Given the magnitude of the Rim wildfire, the impacts it had on regional air quality and the limited sampling of wildfire emissions in the western United States to date, this study provides a valuable dataset to support forestry and regional air quality management, including observations of ERs of a wide number of species from the Rim wildfire.

  4. HSRL-2 aerosol optical measurements and microphysical retrievals vs. airborne in situ measurements during DISCOVER-AQ 2013: an intercomparison study

    P. Sawamura

    2017-06-01

    Full Text Available We present a detailed evaluation of remotely sensed aerosol microphysical properties obtained from an advanced, multi-wavelength high-spectral-resolution lidar (HSRL-2 during the 2013 NASA DISCOVER-AQ field campaign. Vertically resolved retrievals of fine-mode aerosol number, surface-area, and volume concentration as well as aerosol effective radius are compared to 108 collocated, airborne in situ measurement profiles in the wintertime San Joaquin Valley, California, and in summertime Houston, Texas. An algorithm for relating the dry in situ aerosol properties to those obtained by the HSRL at ambient relative humidity is discussed. We show that the HSRL-2 retrievals of ambient fine-mode aerosol surface-area and volume concentrations agree with the in situ measurements to within 25 and 10 %, respectively, once hygroscopic growth adjustments have been applied to the dry in situ data. Despite this excellent agreement for the microphysical properties, extinction and backscatter coefficients at ambient relative humidity derived from the in situ aerosol measurements using Mie theory are consistently smaller than those measured by the HSRL, with average differences of 31 ± 5 % and 53 ± 11 % for California and Texas, respectively. This low bias in the in situ estimates is attributed to the presence of coarse-mode aerosol that are detected by HSRL-2 but that are too large to be well sampled by the in situ instrumentation. Since the retrieval of aerosol volume is most relevant to current regulatory efforts targeting fine particle mass (PM2. 5, these findings highlight the advantages of an advanced 3β + 2α HSRL for constraining the vertical distribution of the aerosol volume or mass loading relevant for air quality.

  5. Performance Analysis of Measurement Inaccuracies of IMU/GPS on Airborne Repeat-pass Interferometric SAR in the Presence of Squint

    Deng Yuan

    2014-08-01

    Full Text Available In the MOtion COmpensation (MOCO approach to airborne repeat-pass interferometric Synthetic Aperture Radar (SAR based on motion measurement data, the measurement inaccuracies of Inertial Measurement Unit/Global Positioning System (IMU/GPS and the positioning errors of the target, which may contribute to the residual uncompensated motion errors, affect the imaging result and interferometric measurement. Considering the effects of the two types of error, this paper builds a mathematical model of residual motion errors in presence of squint, and analyzes the effects on the residual motion errors induced by the measurement inaccuracies of IMU/GPS and the positioning errors of the target. In particular, the effects of various measurement inaccuracies of IMU/GPS on interferometric SAR image quality, interferometric phase, and digital elevation model precision are disscussed. Moreover, the paper quantitatively researches the effects of residual motion errors on airborne repeat-pass interferometric SAR through theoretical and simulated analyses and provides theoretical bases for system design and signal processing.

  6. Airborne Video Surveillance

    Blask, Steven

    2002-01-01

    The DARPA Airborne Video Surveillance (AVS) program was established to develop and promote technologies to make airborne video more useful, providing capabilities that achieve a UAV force multiplier...

  7. The calibration of portable and airborne gamma-ray spectrometers - theory, problems, and facilities

    Loevborg, L.

    1984-10-01

    A gamma-ray spectrometer for use in geological exploration possesses four stripping ratios and three window sensitivities which must be determined to make the instrumentation applicable for field assay or airborne measurement of potassium, uranium, and thorium contents in the ground. Survey organizations in many parts of the world perform the instrument calibration using large pads of concrete which simulate a plane ground of known radioelement concentration. Calibration and monitoring trials with twelve facilities in ten countries prove that moisture absorption, radon exhalation, and particle-size effects can offset a radiometric grade assigned to concrete whose aggregate contains an embedded radioactive mineral. These and other calibration problems are discussed from a combined theoretical and practical viewpoint. (author)

  8. Recent developments in airborne gamma ray surveying

    Grasty, Robert L.

    1999-01-01

    Standardized procedures have been developed for converting airborne gamma ray measurements to ground concentrations of potassium, uranium and thorium. These procedures make use of an airborne calibration range whose ground concentrations should be measured with a calibrated portable spectrometer rather than by taking geochemical samples. Airborne sensitivities and height attenuation coefficients are normally determined from flights over the calibration range but may not be applicable in mountainous areas. Mathematical techniques have been now developed to reduce statistical noise in the airborne measurements by utilizing up to 256 channels of spectral information. (author)

  9. Airborne aldehydes in cabin-air of commercial aircraft: Measurement by HPLC with UV absorbance detection of 2,4-dinitrophenylhydrazones.

    Rosenberger, Wolfgang; Beckmann, Bibiana; Wrbitzky, Renate

    2016-04-15

    This paper presents the strategy and results of in-flight measurements of airborne aldehydes during normal operation and reported "smell events" on commercial aircraft. The aldehyde-measurement is a part of a large-scale study on cabin-air quality. The aims of this study were to describe cabin-air quality in general and to detect chemical abnormalities during the so-called "smell-events". Adsorption and derivatization of airborne aldehydes on 2,4-dinitrophenylhydrazine coated silica gel (DNPH-cartridge) was applied using tailor-made sampling kits. Samples were collected with battery supplied personal air sampling pumps during different flight phases. Furthermore, the influence of ozone was investigated by simultaneous sampling with and without ozone absorption unit (ozone converter) assembled to the DNPH-cartridges and found to be negligible. The method was validated for 14 aldehydes and found to be precise (RSD, 5.5-10.6%) and accurate (recovery, 98-103 %), with LOD levels being 0.3-0.6 μg/m(3). According to occupational exposure limits (OEL) or indoor air guidelines no unusual or noticeable aldehyde pollution was observed. In total, 353 aldehyde samples were taken from two types of aircraft. Formaldehyde (overall average 5.7 μg/m(3), overall median 4.9 μg/m(3), range 0.4-44 μg/m(3)), acetaldehyde (overall average 6.5 μg/m(3), overall median 4.6, range 0.3-90 μg/m(3)) and mostly very low concentrations of other aldehydes were measured on 108 flights. Simultaneous adsorption and derivatization of airborne aldehydes on DNPH-cartridges to the Schiff bases and their HPLC analysis with UV absorbance detection is a useful method to measure aldehydes in cabin-air of commercial aircraft. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. ARM-ACME V: ARM Airborne Carbon Measurements V on the North Slope of Alaska Science and Implementation Plan

    Biraud, S [Lawrence Berkeley National Laboratory

    2015-05-01

    Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO₂ and/or CH₄) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols, and cloud properties at the North Slope of Alaska are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections.

  11. Radiometric study of creep in ingot rolling

    Kubicek, P.; Zamyslovsky, Z.; Uherek, J.

    The radiometric study of creep during ingot rolling performed in the rolling mill of the Vitkovice Iron and Steel Works and the first results are described. Selected sites in 3 to 8 ton ingots were labelled with 2 to 3.7x10 5 Bq of 60 Co and after rolling into blocks, the transposition of the labelled sites of the ingots was investigated. The results indicate creep during rolling, local extension in certain sites under study and help to determine the inevitable bottom crop incurred in the forming. Finally, the requirements put on the radiometric apparatus for the next stages of technological research are presented. (author)

  12. Radon potential mapping of the Tralee-Castleisland and Cavan areas (Ireland) based on airborne gamma-ray spectrometry and geology.

    Appleton, J D; Doyle, E; Fenton, D; Organo, C

    2011-06-01

    The probability of homes in Ireland having high indoor radon concentrations is estimated on the basis of known in-house radon measurements averaged over 10 km × 10 km grid squares. The scope for using airborne gamma-ray spectrometer data for the Tralee-Castleisland area of county Kerry and county Cavan to predict the radon potential (RP) in two distinct areas of Ireland is evaluated in this study. Airborne data are compared statistically with in-house radon measurements in conjunction with geological and ground permeability data to establish linear regression models and produce radon potential maps. The best agreement between the percentage of dwellings exceeding the reference level (RL) for radon concentrations in Ireland (% > RL), estimated from indoor radon data, and modelled RP in the Tralee-Castleisland area is produced using models based on airborne gamma-ray spectrometry equivalent uranium (eU) and ground permeability data. Good agreement was obtained between the % > RL from indoor radon data and RP estimated from eU data in the Cavan area using terrain specific models. In both areas, RP maps derived from eU data are spatially more detailed than the published 10 km grid map. The results show the potential for using airborne radiometric data for producing RP maps.

  13. RADIOMETRIC TECHNIQUES IN HEAVY MINERAL EXPLORATION AND EXPLOITATION

    DEMEIJER, RJ; TANCZOS, IC; STAPEL, C

    1994-01-01

    In recent years the Environmental Research Group of the KVI has been developing a number of radiometric techniques that may be employed in mineral sand exploration. These techniques involve: radiometric fingerprinting for assessing sand provenances and mineralogical composition; thermoluminescence

  14. Unmanned aerial vehicles ('drones') as tools for small scale radiometric surveys

    Luff, R.; Stöhlker, U.; Bossew, P., E-mail: rluff@bfs.de [German Federal Office for Radiation Protection, Salzgitter (Germany)

    2017-07-01

    An UAV has been developed by the Federal Office for Radiation Protection (BfS) and tested in the Chernobyl exclusion zone in September 2016. A commercially available hexacopter has been equipped with a 1.5 cm³ CZT gamma spectrometric detector (μSPEC), GPS, data processing unit (Rasperry PI with Linux) and Wi-Fi for data transmission to the ground base. Optionally a camera can be carried. The system records gamma dose rate every 2 seconds and gamma spectra every 10 minutes. The total cost of the system is significantly below 10k€ which includes the detector (6k€), data acquisition system (0.2k€) and the UAV (1.2k€). The system is very mobile, easy to set up and to operate in the field. Results are plausible and easy to interpret, spatial resolution of the gamma dose rate on the ground is surprisingly high. Measurement results from the Chernobyl exclusion zone show that the sensitivity of the detector allows radiation survey in areas where the dose rate level is above 0.3 μSv/h. Limitation of the small system are the relatively short operation range of a few 100 m and the lack of an altimeter to assure constant flight altitude above ground. Among the results of the exercise were that a high gamma dose rate gradient in the field can be well identified and the observation that the measured gamma dose rate depends relatively little on the flight altitude between 3 and about 15 meters above ground, for a large scale contamination field. As a conclusion, the use of UAVs for radiometric surveys is a promising and viable complement to traditional air-borne reconnaissance for small areas, and an alternative to ground-based surveys in case of high radiation levels or difficult access. (author)

  15. Unmanned aerial vehicles ('drones') as tools for small scale radiometric surveys

    Luff, R.; Stöhlker, U.; Bossew, P.

    2017-01-01

    An UAV has been developed by the Federal Office for Radiation Protection (BfS) and tested in the Chernobyl exclusion zone in September 2016. A commercially available hexacopter has been equipped with a 1.5 cm³ CZT gamma spectrometric detector (μSPEC), GPS, data processing unit (Rasperry PI with Linux) and Wi-Fi for data transmission to the ground base. Optionally a camera can be carried. The system records gamma dose rate every 2 seconds and gamma spectra every 10 minutes. The total cost of the system is significantly below 10k€ which includes the detector (6k€), data acquisition system (0.2k€) and the UAV (1.2k€). The system is very mobile, easy to set up and to operate in the field. Results are plausible and easy to interpret, spatial resolution of the gamma dose rate on the ground is surprisingly high. Measurement results from the Chernobyl exclusion zone show that the sensitivity of the detector allows radiation survey in areas where the dose rate level is above 0.3 μSv/h. Limitation of the small system are the relatively short operation range of a few 100 m and the lack of an altimeter to assure constant flight altitude above ground. Among the results of the exercise were that a high gamma dose rate gradient in the field can be well identified and the observation that the measured gamma dose rate depends relatively little on the flight altitude between 3 and about 15 meters above ground, for a large scale contamination field. As a conclusion, the use of UAVs for radiometric surveys is a promising and viable complement to traditional air-borne reconnaissance for small areas, and an alternative to ground-based surveys in case of high radiation levels or difficult access. (author)

  16. Analysis of L-band radiometric data over the Mediterranean Sea from the SMOS Validation Rehearsal campaign

    Gabarro, C.; Talone, M.; Font, J.

    2009-04-01

    L-band radiometric data obtained with a real aperture airborne radiometer during SMOS validation Rehearsal campaign (April-May 2008) over the NW Mediterranean Sea have been analysed. EMIRAD, a fully polarimetric radiometer developed by the Technical University of Denmark operating in the 1400 - 1427 MHz band, was mounted on board a Skyvan aircraft from the Helsinki University of Technology. Two antennas were used: one facing nadir with 37.6° full aperture at half-power; and one placed towards the rear of the aircraft at 40° zenith angle with 30.6° full aperture at half-power. Two transit flights over the sea from Marseille to Valencia (19 April 2008) and from Valencia to Marseille (3 May 2008) have been studied. Two meteorological and oceanographic buoys were moored 40 Km offshore in front of Tarragona and were overflown during these transits. Additionally, information on sea surface temperature (SST) and sea surface salinity (SSS) was obtained from operational model outputs (Mediterranean Forecasting System - Mediterranean Operational Oceanography Network) and wind speed from QuikSCAT. Measured brightness temperatures (Tb) have been compared with modelled Tb, using a semi-empirical emissivity model: Klein and Swift model is used to define the dielectric constant and Hollinger model for the rough sea emissivity contribution. Comparisons show that in general measured Tb variability fits with modelled variability, although a bias is observed in the aft V channel.

  17. Airborne Laser Polarization Sensor

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  18. Column carbon dioxide and water vapor measurements by an airborne triple-pulse integrated path differential absorption lidar: novel lidar technologies and techniques with path to space

    Singh, U. N.; Petros, M.; Refaat, T. F.; Yu, J.; Ismail, S.

    2017-09-01

    The 2-micron wavelength region is suitable for atmospheric carbon dioxide (CO2) measurements due to the existence of distinct absorption features for the gas at this wavelength region [1]. For more than 20 years, researchers at NASA Langley Research Center (LaRC) have developed several high-energy and high repetition rate 2-micron pulsed lasers [2]. Currently, LaRC team is engaged in designing, developing and demonstrating a triple-pulsed 2-micron direct detection Integrated Path Differential Absorption (IPDA) lidar to measure the weighted-average column dry-air mixing ratios of carbon dioxide (XCO2) and water vapor (XH2O) from an airborne platform [1, 3-5]. This novel technique allows measurement of the two most dominant greenhouse gases, simultaneously and independently, using a single instrument. This paper will provide status and details of the development of this airborne 2-micron triple-pulse IPDA lidar. The presented work will focus on the advancement of critical IPDA lidar components. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver and detector upgrades, laser packaging and lidar integration. Future plans for IPDA lidar ground integration, testing and flight validation will also be discussed. This work enables new Earth observation measurements, while reducing risk, cost, size, volume, mass and development time of required instruments.

  19. KERNEL MAD ALGORITHM FOR RELATIVE RADIOMETRIC NORMALIZATION

    Y. Bai

    2016-06-01

    Full Text Available The multivariate alteration detection (MAD algorithm is commonly used in relative radiometric normalization. This algorithm is based on linear canonical correlation analysis (CCA which can analyze only linear relationships among bands. Therefore, we first introduce a new version of MAD in this study based on the established method known as kernel canonical correlation analysis (KCCA. The proposed method effectively extracts the non-linear and complex relationships among variables. We then conduct relative radiometric normalization experiments on both the linear CCA and KCCA version of the MAD algorithm with the use of Landsat-8 data of Beijing, China, and Gaofen-1(GF-1 data derived from South China. Finally, we analyze the difference between the two methods. Results show that the KCCA-based MAD can be satisfactorily applied to relative radiometric normalization, this algorithm can well describe the nonlinear relationship between multi-temporal images. This work is the first attempt to apply a KCCA-based MAD algorithm to relative radiometric normalization.

  20. Radiometric system for clinical applications in the National Health System

    Mesa Perez, G.; Arteche Diaz, R.; Camejo Batista, A.; Fonfria Bragado, C.

    2013-01-01

    In this paper it is presented the radiometric detection system SRNIC-02, manufactured at CEADEN. The system has three major components: a well-type Nal(TI) scintillator detector with its collimator, a measurement module, and the application software, which allows fixing the working parameters of the system, as well as the acquisition and processing of data. The system has two main applications in the National Health System, one for the quality control in Radiopharmacy, and in RIA/IRMA blood tests. There are 16 systems installed, in 13 provinces of the country up to this date. (Author)

  1. Radiometric method for the rapid detection of Leptospira organisms

    Manca, N.; Verardi, R.; Colombrita, D.; Ravizzola, G.; Savoldi, E.; Turano, A.

    1986-01-01

    A rapid and sensitive radiometric method for detection of Leptospira interrogans serovar pomona and Leptospira interrogans serovar copenhageni is described. Stuart's medium and Middlebrook TB (12A) medium supplemented with bovine serum albumin, catalase, and casein hydrolysate and labeled with 14 C-fatty acids were used. The radioactivity was measured in a BACTEC 460. With this system, Leptospira organisms were detected in human blood in 2 to 5 days, a notably shorter time period than that required for the majority of detection techniques

  2. Radiometric method for the rapid detection of Leptospira organisms

    Manca, N.; Verardi, R.; Colombrita, D.; Ravizzola, G.; Savoldi, E.; Turano, A.

    1986-02-01

    A rapid and sensitive radiometric method for detection of Leptospira interrogans serovar pomona and Leptospira interrogans serovar copenhageni is described. Stuart's medium and Middlebrook TB (12A) medium supplemented with bovine serum albumin, catalase, and casein hydrolysate and labeled with /sup 14/C-fatty acids were used. The radioactivity was measured in a BACTEC 460. With this system, Leptospira organisms were detected in human blood in 2 to 5 days, a notably shorter time period than that required for the majority of detection techniques.

  3. Notes on the radiometric and geochemical survey of Leyte Island

    Santos, G. Jr.

    1982-01-01

    Radioactivity measurements using the Scintrex GIS-4 portable scintillometer were conducted along the periphery of the island. These radiometric readings as well as sediments were obtained along the streams draining into the sea. A total of 174 stream sediments samples were collected. Minus 80 mesh sediment fraction was analyzed for mobile or extractable uranium. Results indicated that the background values of radioactivity and uranium in stream sediments were 25 counts per second (cps) and 0.3 ppm, respectively. The San Isidro and Vilaba areas which are located in the northern part of Leyte have greater than 3 times above background radioactivity and uranium in the stream sediments. (author)

  4. On the lower of limit detection of radiometric systems

    Kamburov, H.; Boneva, S.

    1983-01-01

    The existing definitions of the quantity Asub(min), the lower detection limit, introduced as a characteristic of the sensitivity of radiometric systems are reviewed. A convenient way is found for comparing the different definitions by showing that each definition is connected with a specific value of the probability a of Type I error. The detection limits are calculated for a normal and Poisson distributions of the measured quantities. A criterion is proposed for the applicability of the normal distiribution to the problem of determining the lower detection limit

  5. Estimating Aboveground Forest Carbon Stock of Major Tropical Forest Land Uses Using Airborne Lidar and Field Measurement Data in Central Sumatra

    Thapa, R. B.; Watanabe, M.; Motohka, T.; Shiraishi, T.; shimada, M.

    2013-12-01

    Tropical forests are providing environmental goods and services including carbon sequestration, energy regulation, water fluxes, wildlife habitats, fuel, and building materials. Despite the policy attention, the tropical forest reserve in Southeast Asian region is releasing vast amount of carbon to the atmosphere due to deforestation. Establishing quality forest statistics and documenting aboveground forest carbon stocks (AFCS) are emerging in the region. Airborne and satellite based large area monitoring methods are developed to compliment conventional plot based field measurement methods as they are costly, time consuming, and difficult to implement for large regions. But these methods still require adequate ground measurements for calibrating accurate AFCS model. Furthermore, tropical region comprised of varieties of natural and plantation forests capping higher variability of forest structures and biomass volumes. To address this issue and the needs for ground data, we propose the systematic collection of ground data integrated with airborne light detection and ranging (LiDAR) data. Airborne LiDAR enables accurate measures of vertical forest structure, including canopy height and volume demanding less ground measurement plots. Using an appropriate forest type based LiDAR sampling framework, structural properties of forest can be quantified and treated similar to ground measurement plots, producing locally relevant information to use independently with satellite data sources including synthetic aperture radar (SAR). In this study, we examined LiDAR derived forest parameters with field measured data and developed general and specific AFCS models for tropical forests in central Sumatra. The general model is fitted for all types of natural and plantation forests while the specific model is fitted to the specific forest type. The study region consists of natural forests including peat swamp and dry moist forests, regrowth, and mangrove and plantation forests

  6. Determination of degree of compacting and of moisture content by radiometric probes

    Martinec, J.; Paul, P.

    1977-01-01

    A survey is given of radiometric probes used for measuring bulk density and moisture content. Surface probes are used in depths of up to 20 cm with an accuracy of 10%, drive-in probes are used to depths of up to 50 cm with a 4% error, depth probes are used for measuring in depths of 30 to 50 cm with an accuracy of roughly 5% and bulk density in depths of 10 to 150 cm may be measured with an accuracy of 2% using a lysimeter. Changes in the bulk density and soil moisture of the subsoil of an airport runway were studied radiometrically in dependence on time and depth. The dependence is represented graphically. The results of radiometric measurements were compared with the conventional method using a lysimeter probe; the comparison showed that the results were lower by about 7% for the moisture content and higher by about 8% for the bulk density. Radiometric measurements for determining bulk density and soil moisture are advantageous in that they allow the measurement of a great number of sites without any major disturbance of the measured material and results are available immediately on measurement. The economic effect is significant in a large number of measurements carried out on a surface having the same chemical composition and similar grain size which does not necessitate calibration of the instruments to be made more than once a week. The NZK-201 probe by Tesla does not provide sufficiently accurate information on the moisture and density of the earths probed

  7. Monitoring and evaluation techniques for airborne contamination

    Yihua, Xia [China Inst. of Atomic Energy, Beijing (China)

    1997-06-01

    Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

  8. Monitoring and evaluation techniques for airborne contamination

    Xia Yihua

    1997-01-01

    Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

  9. Assessing exergy of forest ecosystem using airborne and satellite data

    Brovkina, Olga; Fabianek, Tomas; Lukes, Petr; Zemek, Frantisek

    2017-04-01

    Interactions of the energy flows of forest ecosystem with environment are formed by a suite of forest structure, functions and pathways of self-control. According to recent thermodynamic theory for open systems, concept of exergy of solar radiation has been applied to estimate energy consumptions on evapotranspiration and biomass production in forest ecosystem or to indicate forest decline and human land use impact on ecosystem stability. However, most of the methods for exergy estimation in forest ecosystem is not stable and its physical meaning remains on the surface. This study was aimed to contribute to understanding the exergy of forest ecosystem using combination of remote sensing (RS) and eddy covariance technologies, specifically: 1/to explore exergy of solar radiation depending on structure of solar spectrum (number of spectral bands of RS data), and 2/to explore the relationship between exergy and flux tower eddy covariance measurements. Two study forest sites were located in Western Beskids in the Czech Republic. The first site was dominated by young Norway spruce, the second site was dominated by mature European beech. Airborne hyperspectral data in VNIR, SWIR and TIR spectral regions were acquired 9 times for study sites during a vegetation periods in 2015-2016. Radiometric, geometric and atmospheric corrections of airborne data were performed. Satellite multispectral Landsat-8 cloud-free 21 scenes were downloaded and atmospherically corrected for the period from April to November 2015-2016. Evapotranspiration and latent heat fluxes were collected from operating flux towers located on study sites according to date and time of remote sensing data acquisition. Exergy was calculated for each satellite and airborne scene using various combinations of spectral bands as: Ex=E^out (K+ln E^out/E^in )+R, where Ein is the incoming solar energy, Eout is the reflected solar energy, R = Ein-Eout is absorbed energy, Eout/Ein is albedo and K is the Kullback increment

  10. Airborne observations of far-infrared upwelling radiance in the Arctic

    Q. Libois

    2016-12-01

    Full Text Available The first airborne measurements of the Far-InfraRed Radiometer (FIRR were performed in April 2015 during the panarctic NETCARE campaign. Vertical profiles of spectral upwelling radiance in the range 8–50 µm were measured in clear and cloudy conditions from the surface up to 6 km. The clear sky profiles highlight the strong dependence of radiative fluxes to the temperature inversion typical of the Arctic. Measurements acquired for total column water vapour from 1.5 to 10.5 mm also underline the sensitivity of the far-infrared greenhouse effect to specific humidity. The cloudy cases show that optically thin ice clouds increase the cooling rate of the atmosphere, making them important pieces of the Arctic energy balance. One such cloud exhibited a very complex spatial structure, characterized by large horizontal heterogeneities at the kilometre scale. This emphasizes the difficulty of obtaining representative cloud observations with airborne measurements but also points out how challenging it is to model polar clouds radiative effects. These radiance measurements were successfully compared to simulations, suggesting that state-of-the-art radiative transfer models are suited to study the cold and dry Arctic atmosphere. Although FIRR in situ performances compare well to its laboratory performances, complementary simulations show that upgrading the FIRR radiometric resolution would greatly increase its sensitivity to atmospheric and cloud properties. Improved instrument temperature stability in flight and expected technological progress should help meet this objective. The campaign overall highlights the potential for airborne far-infrared radiometry and constitutes a relevant reference for future similar studies dedicated to the Arctic and for the development of spaceborne instruments.

  11. Vicarious absolute radiometric calibration of GF-2 PMS2 sensor using permanent artificial targets in China

    Liu, Yaokai; Li, Chuanrong; Ma, Lingling; Wang, Ning; Qian, Yonggang; Tang, Lingli

    2016-10-01

    GF-2, launched on August 19 2014, is one of the high-resolution land resource observing satellite of the China GF series satellites plan. The radiometric performance evaluation of the onboard optical pan and multispectral (PMS2) sensor of GF-2 satellite is very important for the further application of the data. And, the vicarious absolute radiometric calibration approach is one of the most useful way to monitor the radiometric performance of the onboard optical sensors. In this study, the traditional reflectance-based method is used to vicarious radiometrically calibrate the onboard PMS2 sensor of GF-2 satellite using three black, gray and white reflected permanent artificial targets located in the AOE Baotou site in China. Vicarious field calibration campaign were carried out in the AOE-Baotou calibration site on 22 April 2016. And, the absolute radiometric calibration coefficients were determined with in situ measured atmospheric parameters and surface reflectance of the permanent artificial calibration targets. The predicted TOA radiance of a selected desert area with our determined calibrated coefficients were compared with the official distributed calibration coefficients. Comparison results show a good consistent and the mean relative difference of the multispectral channels is less than 5%. Uncertainty analysis was also carried out and a total uncertainty with 3.87% is determined of the TOA radiance.

  12. Air Kerma above environmental radiometric calibration facility for field equipment

    Conti, C.C.; Sachett, I.A.; Bertelli, L.; Lopes, R.T.

    2000-01-01

    The use of gamma ray spectrometers broadened the aims of gamma ray surveys, stead of measuring only the gross radiation, as was done with the GM tubes, it is now possible to be used for uranium exploration, geological mapping as an aid to the exploration of non radioactive ores like gold and tin, radiation background measurements to identify hot spots for radiation hazard evaluation and environmental monitoring of fallout from radiological and nuclear accidents. It became necessary to carefully and precisely calibrate the field equipment to be used to get all the information from such uses. There is an environmental radiometric calibration facility for field equipment, consisting of eight radioactive concrete sources, at the Institute of Radioprotection and Dosimetry - IRD (CNEN/Brazil). These sources are cylindrical with 3 m diameter, 0.5 m thick and weigh about 7.5 tons each. The amount and type of the radioactive material, 238 U and 232 Th and 40 K ores in secular radioactive equilibrium, added to the concrete to simulate rock outcrops, varies in order to obtain different gamma fields, varying in both energy and intensity. These different radiation fields were measured with a HPGe portable detector, specifically calibrated for spectrum stripping, and the air kerma energy distribution was determined for each concrete source and compared with the total air kerma calculated from the nuclide concentration and by others radiometric methods. (author)

  13. Nitrogen Dioxide Observations from the Geostationary Trace Gas and Aerosol Sensor Optimization (GeoTaso) Airborne Instrument: Retrieval Algorithm and Measurements During DISCOVER-AQ Texas 2013

    Nowlan, Caroline R.; Liu, Xiong; Leitch, James W.; Chance, Kelly; Abad, Gonzalo Gonzalez; Liu, Xiaojun; Zoogman, Peter; Cole, Joshua; Delker, Thomas; Good, William; hide

    2016-01-01

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA Falcon aircraft in its first intensive field measurement campaign during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Earth Venture Mission over Houston, Texas, in September 2013. Measurements of backscattered solar radiation between 420 and 465 nm collected on 4 days during the campaign are used to determine slant column amounts of NO2 at 250 m x 250 m spatial resolution with a fitting precision of 2.2 x 10(exp 15) molecules/sq cm. These slant columns are converted to tropospheric NO2 vertical columns using a radiative transfer model and trace gas profiles from the Community Multiscale Air Quality (CMAQ) model. Total column NO2 from GeoTASO is well correlated with ground-based Pandora observations (r = 0.90 on the most polluted and cloud-free day of measurements and r = 0.74 overall), with GeoTASO NO2 slightly higher for the most polluted observations. Surface NO2 mixing ratios inferred from GeoTASO using the CMAQ model show good correlation with NO2 measured in situ at the surface during the campaign (r = 0.85). NO2 slant columns from GeoTASO also agree well with preliminary retrievals from the GEO-CAPE Airborne Simulator (GCAS) which flew on the NASA King Air B200 (r = 0.81, slope = 0.91). Enhanced NO2 is resolvable over areas of traffic NOx emissions and near individual petrochemical facilities.

  14. Deep Space Network Radiometric Remote Sensing Program

    Walter, Steven J.

    1994-01-01

    Planetary spacecraft are viewed through a troposphere that absorbs and delays radio signals propagating through it. Tropospheric water, in the form of vapor, cloud liquid, and precipitation, emits radio noise which limits satellite telemetry communication link performance. Even at X-band, rain storms have severely affected several satellite experiments including a planetary encounter. The problem will worsen with DSN implementation of Ka-band because communication link budgets will be dominated by tropospheric conditions. Troposphere-induced propagation delays currently limit VLBI accuracy and are significant sources of error for Doppler tracking. Additionally, the success of radio science programs such as satellite gravity wave experiments and atmospheric occultation experiments depends on minimizing the effect of water vapor-induced propagation delays. In order to overcome limitations imposed by the troposphere, the Deep Space Network has supported a program of radiometric remote sensing. Currently, water vapor radiometers (WVRs) and microwave temperature profilers (MTPs) support many aspects of the Deep Space Network operations and research and development programs. Their capability to sense atmospheric water, microwave sky brightness, and atmospheric temperature is critical to development of Ka-band telemetry systems, communication link models, VLBI, satellite gravity wave experiments, and radio science missions. During 1993, WVRs provided data for propagation model development, supported planetary missions, and demonstrated advanced tracking capability. Collection of atmospheric statistics is necessary to model and predict performance of Ka-band telemetry links, antenna arrays, and radio science experiments. Since the spectrum of weather variations has power at very long time scales, atmospheric measurements have been requested for periods ranging from one year to a decade at each DSN site. The resulting database would provide reliable statistics on daily

  15. Detecting payload performance based on relative radiometric characteristic: case of the optical sensors

    Han, Jie; Li, Shengyang; Zhang, Tao; Qin, Bangyong

    2016-10-01

    In this paper, we propose a novel algorithm for accurately estimating the degree of radiometric non-uniformity in remote sensing images. The algorithm was tested on high-quality images and heavily striping images, and quantitative analyses were conducted to evaluate the performance for each band by measuring the radiometric non-uniformity of the images. The results demonstrated that the proposed algorithm exhibits high accuracy and stability compared with traditional algorithms. The radiometric performance of TianGong-1 short-wave infrared images was calculated using this new method, and it was highly correlated with the solar angle, pitch angle and refrigerator thermal according to the Apriori algorithm. Based on these results, we have proposed a strategy for restricting increases in striping.

  16. The actinic UV-radiation budget during the ESCOMPTE campaign 2001: results of airborne measurements with the microlight research aircraft D-MIFU

    Junkermann, Wolfgang

    2005-03-01

    During the ESCOMPTE campaign 2001, the vertical distribution of ultraviolet actinic radiation was investigated with concurrent measurements of ozone, aerosol size distributions, and scattering coefficients using a microlight aircraft as airborne platform. Three-dimensional (3D) measurements were performed on a regional scale in the area between Avignon, Aix-en-Provence, and Marseille up to an altitude of 4000 m a.s.l. The results show a pronounced dependence of the vertical actinic flux distribution on aerosol load and stratification while horizontally no significant variability was observed. Furthermore, investigations under cloudy conditions and in the vicinity of cumulus clouds were performed allowing comparisons with one-dimensional and recently published three-dimensional model results. Cloud effects of scattered convective clouds were often found to be masked by aerosols and the aerosol content was generally the dominating factor controlling radiation transfer.

  17. Substoichiometric method in the simple radiometric analysis

    Ikeda, N.; Noguchi, K.

    1979-01-01

    The substoichiometric method is applied to simple radiometric analysis. Two methods - the standard reagent method and the standard sample method - are proposed. The validity of the principle of the methods is verified experimentally in the determination of silver by the precipitation method, or of zinc by the ion-exchange or solvent-extraction method. The proposed methods are simple and rapid compared with the conventional superstoichiometric method. (author)

  18. Radiometric characterization of Landsat Collection 1 products

    Micijevic, Esad; Haque, Md. Obaidul; Mishra, Nischal

    2017-09-01

    Landsat data in the U.S. Geological Survey (USGS) archive are being reprocessed to generate a tiered collection of consistently geolocated and radiometrically calibrated products that are suitable for time series analyses. With the implementation of the collection management, no major updates will be made to calibration of the Landsat sensors within a collection. Only calibration parameters needed to maintain the established calibration trends without an effect on derived environmental records will be regularly updated, while all other changes will be deferred to a new collection. This first collection, Collection 1, incorporates various radiometric calibration updates to all Landsat sensors including absolute and relative gains for Landsat 8 Operational Land Imager (OLI), stray light correction for Landsat 8 Thermal Infrared Sensor (TIRS), absolute gains for Landsat 4 and 5 Thematic Mappers (TM), recalibration of Landsat 1-5 Multispectral Scanners (MSS) to ensure radiometric consistency among different formats of archived MSS data, and a transfer of Landsat 8 OLI reflectance based calibration to all previous Landsat sensors. While all OLI/TIRS, ETM+ and majority of TM data have already been reprocessed to Collection 1, a completion of MSS and remaining TM data reprocessing is expected by the end of this year. It is important to note that, although still available for download from the USGS web pages, the products generated using the Pre-Collection processing do not benefit from the latest radiometric calibration updates. In this paper, we are assessing radiometry of solar reflective bands in Landsat Collection 1 products through analysis of trends in on-board calibrator and pseudo invariant site (PICS) responses.

  19. Radiometric relations of a sugarcane crop

    Machado, E.C.; Pereira, A.R.; Camargo, M.B.P. de; Fahl, J.I.

    1985-01-01

    The radiometric relations of a sugarcane crop, cv. NA56-79, are studied during the period of maximum leaf area index. The coefficients of reflection, transmission and absorption of the incoming solar radiation were function of solar elevation and the waveband considered. The photosynthetically active radiation was always less reflected and transmitted but more absorved than the near infrared radiation. (M.A.C.) [pt

  20. Evaluation of a radiometric method for studying bacterial activity in the presence of antimicrobial agents

    Cutler, R.R.; Wilson, P.; Clarke, F.V. (Newham District Microbiology Labs., St. Andrews Hospital, London (UK))

    1989-06-01

    In a study involving 2760 tests, the BACTEC semi-automatic radiometric method which measures bacterial metabolic activity and produces a BACTEC growth index, was compared with two conventional methods commonly used for determining growth, absorbance and viable counts. In 92% of radiometry tests the suppression of growth was inversely related to the antibiotic concentration. This compared with 83% for absorbance and 63% for viable counts. The radiometric method was found to be more rapid, easier to use and more reproducible in determining the effect of antibiotics on the activity of bacteria than viable counting or absorbance methods. (author).

  1. Radiometric survey in mammography: problems and challenges; Levantamento radiometrico em mamografia: problemas e desafios

    Navarro, M.V.T.; Navarro, V.C.C.; Garcia, I.F.M.; Ferreira, M.J.; Macedo, E.M., E-mail: navarro@ifba.edu.br [Instituto Federal da Bahia (LABPROSAUD/IFBA), Salvador, BA (Brazil). Laboratorio de Produtos para a Saude

    2015-07-01

    In addition to being mandatory, the radiometric survey is a necessity, especially in the Brazilian reality with the construction of smaller and smaller rooms. However, calibration conditions, the instrumentation and its use, can produce underestimated factors. Measures made at Labprosaud/IFBA, with five different instruments and the ISO N 25 radiation quality, show the possibility of the values presented in the radiometric surveys are underestimated by up to 10 times. The results indicate the need for meters to be calibrated in ISO N qualities, in mammography energy range, in integrated dose mode and exposure times shorter or equal to 1 s. (author)

  2. Evaluation of a radiometric method for studying bacterial activity in the presence of antimicrobial agents

    Cutler, R.R.; Wilson, P.; Clarke, F.V.

    1989-01-01

    In a study involving 2760 tests, the BACTEC semi-automatic radiometric method which measures bacterial metabolic activity and produces a BACTEC growth index, was compared with two conventional methods commonly used for determining growth, absorbance and viable counts. In 92% of radiometry tests the suppression of growth was inversely related to the antibiotic concentration. This compared with 83% for absorbance and 63% for viable counts. The radiometric method was found to be more rapid, easier to use and more reproducible in determining the effect of antibiotics on the activity of bacteria than viable counting or absorbance methods. (author)

  3. Airborne iodine-125 arising from surface contamination

    Kwok, C.S.; Hilditch, T.E.

    1982-01-01

    Measurements of airborne 125 I were made during the subdivision of 740 MBq stocks of 125 I iodide solution in a hospital dispensary. Within the fume cupboard the mean airborne 125 I concentration was 3.5 +- 2.9 kBqm -3 . No airborne concentration contamination was found outside the fume cupboard during these dispensing sessions. The airborne 125 I concentration arising from deliberate surface contamination (50 μl, 3.7-6.3 MBq) of the top of a lead pot was measured at a height simulating face level at an open work bench. There was a progressive fall in airborne concentration over seven days but even then the level was still significantly above background. Measurements made with the extraction system of the fume cupboard in operation were 2-3 times lower. (U.K.)

  4. GEOMETRIC AND RADIOMETRIC EVALUATION OF RASAT IMAGES

    A. Cam

    2016-06-01

    Full Text Available RASAT, the second remote sensing satellite of Turkey, was designed and assembled, and also is being operated by TÜBİTAK Uzay (Space Technologies Research Institute (Ankara. RASAT images in various levels are available free-of-charge via Gezgin portal for Turkish citizens. In this paper, the images in panchromatic (7.5 m GSD and RGB (15 m GSD bands in various levels were investigated with respect to its geometric and radiometric characteristics. The first geometric analysis is the estimation of the effective GSD as less than 1 pixel for radiometrically processed level (L1R of both panchromatic and RGB images. Secondly, 2D georeferencing accuracy is estimated by various non-physical transformation models (similarity, 2D affine, polynomial, affine projection, projective, DLT and GCP based RFM reaching sub-pixel accuracy using minimum 39 and maximum 52 GCPs. The radiometric characteristics are also investigated for 8 bits, estimating SNR between 21.8-42.2, and noise 0.0-3.5 for panchromatic and MS images for L1R when the sea is masked to obtain the results for land areas. The analysis show that RASAT images satisfies requirements for various applications. The research is carried out in Zonguldak test site which is mountainous and partly covered by dense forest and urban areas.

  5. Airborne differential absorption lidar for water vapour measurements in the upper troposphere and lower stratosphere in the spectral region around 940 nm

    Poberaj, G.

    2000-07-01

    Two all-solid-state laser systems were developed and studied in detail to optimise their performance for an airborne water vapour differential absorption lidar (DIAL). Their special features are high average output powers and excellent spectral properties in the 940-nm spectral region relevant for monitoring very low water vapour contents in the upper troposphere and lower stratosphere. One system is an injection-seeded pulsed Ti:sapphire ring laser with a spectral bandwidth of 105 MHz and an average power of 1.1 W. The other system is an injection-seeded optical parametric oscillator (OPO) in a ring configuration. Using KTP as nonlinear crystal, a signal output with a spectral bandwidth of 140 MHz and an average power of 1.2 W was achieved. Both systems, the Ti:sapphire ring laser and the KTP OPO, possess spectral purity values higher than 99%. The pump source for these systems is a frequency doubled diode-pumped Nd:YAG laser operating at a repetition rate of 100 Hz. The KTP OPO system has been used as a transmitter in a new airborne water vapour DIAL instrument. For the first time, measurements of two-dimensional water vapour distributions with a high vertical (500 m) and horizontal (20 km) resolution across several potential vorticity streamers were performed. Very low water vapour mixing ratios (10-50 ppmv) and strong gradients were observed in the tropopause region. The sensitivity of the DIAL instrument in the centre of a stratospheric intrusion ranges from 3% in the near field to 12% in the far field (4 km). The first comparison experiments with in situ measuring instruments show a good agreement. Considerable differences are found between DIAL measurements and data obtained from the ECMWF operational analyses and a mesoscale numerical model. (orig.)

  6. Multiple scattering effects on the Linear Depolarization Ratio (LDR) measured during CaPE by a Ka-band air-borne radar

    Iguchi, Toshio; Meneghini, Robert

    1993-01-01

    Air-borne radar measurements of thunderstorms were made as part of the CaPE (Convection and Precipitation/Electrification) experiment in Florida in July 1991. The radar has two channels, X-band (10 GHz) and Ka-band (34.5 GHz), and is capable of measuring cross-polarized returns as well as co-polarized returns. In stratiform rain, the cross-polarized components can be observed only at the bright band region and from the surface reflection. The linear depolarization ratios (LDR's) measured at X-band and Ka-band at the bright band are nearly equal. In convective rain, however, the LDR in Ka-band often exceeds the X-band LDR by several dB, and sometimes by more than 10 dB, reaching LDR values of up to -5 dB over heavy convective rain. For randomly oriented hydrometeors, such high LDR values cannot be explained by single scattering from non-spherical scattering particles alone. Because the LDR by single backscatter depends weakly on the wavelength, the difference between the Ka-band and X-band LDR's suggests that multiple scattering effects prevail in the Ka-band LDR. In order to test this inference, the magnitude of the cross-polarized component created by double scattering was calculated using the parameters of the airborne radar, which for both frequencies has beamwidths of 5.1 degrees and pulse widths of 0.5 microsecond. Uniform rain beyond the range of 3 km is assumed.

  7. Optical Airborne Tracker System

    National Aeronautics and Space Administration — The Optical Airborne Tracker System (OATS) is an airborne dual-axis optical tracking system capable of pointing at any sky location or ground target.  The objectives...

  8. Predictors of Airborne Endotoxin Concentrations in Inner City Homes

    Mazique, D; Diette, GB; Breysse, PN; Matsui, EC; McCormack, MC; Curtin-Brosnan, J; Williams, D; Peng, RD; Hansel, NN

    2011-01-01

    Few studies have assessed in-home factors which contribute to airborne endotoxin concentrations. In 85 inner-city Baltimore homes, we found no significant correlation between settled dust and airborne endotoxin concentrations. Certain household activities and characteristics, including frequency of dusting, air conditioner use and type of flooring, explained 36–42% of the variability of airborne concentrations. Measurements of both airborne and settled dust endotoxin concentrations may be needed to fully characterize domestic exposure in epidemiologic investigations. PMID:21429483

  9. Radiometric calibration of digital cameras using neural networks

    Grunwald, Michael; Laube, Pascal; Schall, Martin; Umlauf, Georg; Franz, Matthias O.

    2017-08-01

    Digital cameras are used in a large variety of scientific and industrial applications. For most applications, the acquired data should represent the real light intensity per pixel as accurately as possible. However, digital cameras are subject to physical, electronic and optical effects that lead to errors and noise in the raw image. Temperature- dependent dark current, read noise, optical vignetting or different sensitivities of individual pixels are examples of such effects. The purpose of radiometric calibration is to improve the quality of the resulting images by reducing the influence of the various types of errors on the measured data and thus improving the quality of the overall application. In this context, we present a specialized neural network architecture for radiometric calibration of digital cameras. Neural networks are used to learn a temperature- and exposure-dependent mapping from observed gray-scale values to true light intensities for each pixel. In contrast to classical at-fielding, neural networks have the potential to model nonlinear mappings which allows for accurately capturing the temperature dependence of the dark current and for modeling cameras with nonlinear sensitivities. Both scenarios are highly relevant in industrial applications. The experimental comparison of our network approach to classical at-fielding shows a consistently higher reconstruction quality, also for linear cameras. In addition, the calibration is faster than previous machine learning approaches based on Gaussian processes.

  10. Off-line radiometric analysis of Planck-LFI data

    Tomasi, M; Mennella, A; Bersanelli, M [Dipartimento di Fisica, Universita degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Galeotta, S; Maris, M [LFI-DPC INAF-OATs, Via Tiepolo 11, 34131 Trieste (Italy); Lowe, S R [Jodrell Bank Centre for Astrophysics, The University of Manchester, Manchester, M13 9PL (United Kingdom); Mendes, L [Planck Science Office, European Space Agency, ESAC, P.O. box 78, 28691 Villanueva de la Canada, Madrid (Spain); Leonardi, R; Meinhold, P [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States); Villa, F; Sandri, M; Cuttaia, F; Terenzi, L; Valenziano, L; Butler, R C [INAF-IASF Bologna, Via Gobetti, 101, 40129, Bologna (Italy); Cappellini, B [INAF-IASF Milano, Via E. Bassini 15, 20133 Milano (Italy); Gregorio, A [Department of Physics, University of Trieste, Via Valerio, 2 Trieste I-34127 (Italy); Salmon, M J [Departamento de IngenierIa de Comunicaciones, Universidad de Cantabria, Avenida de los Castros s/n. 39005 Santander (Spain); Binko, P [ISDC Data Centre for Astrophysics, University of Geneva, ch. d' Ecogia 16, 1290 Versoix (Switzerland); D' Arcangelo, O, E-mail: tomasi@lambrate.inaf.i [IFP-CNR, Via Cozzi 53, Milano (Italy)

    2009-12-15

    The Planck Low Frequency Instrument (LFI) is an array of 22 pseudo-correlation radiometers on-board the Planck satellite to measure temperature and polarization anisotropies in the Cosmic Microwave Background (CMB) in three frequency bands (30, 44 and 70 GHz). To calibrate and verify the performances of the LFI, a software suite named LIFE has been developed. Its aims are to provide a common platform to use for analyzing the results of the tests performed on the single components of the instrument (RCAs, Radiometric Chain Assemblies) and on the integrated Radiometric Array Assembly (RAA). Moreover, its analysis tools are designed to be used during the flight as well to produce periodic reports on the status of the instrument. The LIFE suite has been developed using a multi-layered, cross-platform approach. It implements a number of analysis modules written in RSI IDL, each accessing the data through a portable and heavily optimized library of functions written in C and C++. One of the most important features of LIFE is its ability to run the same data analysis codes both using ground test data and real flight data as input. The LIFE software suite has been successfully used during the RCA/RAA tests and the Planck Integrated System Tests. Moreover, the software has also passed the verification for its in-flight use during the System Operations Verification Tests, held in October 2008.

  11. Off-line radiometric analysis of Planck-LFI data

    Tomasi, M; Mennella, A; Bersanelli, M; Galeotta, S; Maris, M; Lowe, S R; Mendes, L; Leonardi, R; Meinhold, P; Villa, F; Sandri, M; Cuttaia, F; Terenzi, L; Valenziano, L; Butler, R C; Cappellini, B; Gregorio, A; Salmon, M J; Binko, P; D'Arcangelo, O

    2009-01-01

    The Planck Low Frequency Instrument (LFI) is an array of 22 pseudo-correlation radiometers on-board the Planck satellite to measure temperature and polarization anisotropies in the Cosmic Microwave Background (CMB) in three frequency bands (30, 44 and 70 GHz). To calibrate and verify the performances of the LFI, a software suite named LIFE has been developed. Its aims are to provide a common platform to use for analyzing the results of the tests performed on the single components of the instrument (RCAs, Radiometric Chain Assemblies) and on the integrated Radiometric Array Assembly (RAA). Moreover, its analysis tools are designed to be used during the flight as well to produce periodic reports on the status of the instrument. The LIFE suite has been developed using a multi-layered, cross-platform approach. It implements a number of analysis modules written in RSI IDL, each accessing the data through a portable and heavily optimized library of functions written in C and C++. One of the most important features of LIFE is its ability to run the same data analysis codes both using ground test data and real flight data as input. The LIFE software suite has been successfully used during the RCA/RAA tests and the Planck Integrated System Tests. Moreover, the software has also passed the verification for its in-flight use during the System Operations Verification Tests, held in October 2008.

  12. Radiometric titration of thallium(III) with EDTA

    Rao, V.R.S.; Pulla Rao, Ch.; Tataiah, G.

    1978-01-01

    Radioactive solutions containing very small amounts of thallium(III) can be determined by radiometric titration using ammonia as hydrolysing agent. Aqueous solution of thallium(I) (both inactive and radioactive) is treated with bromine water till the appearance of the brown colour of bromine, and the solution is warmed to 80 deg C to expel the excess bromine. By this procedure all thallium(I) is quantitatively oxidised to thallium(III). An aqueous solution of ammonia is added to precipitate thallium(III) as thallic oxide. It is then filtered, washed with water to free it from bromide and then dissolved in 2N HCl and the solution is then standardised. 2 ml of this solution is transferred to a 20 ml volumetric flask, 1 ml of radioactive thallium(III) solution to be standardised is added as well as incremental amounts of EDTA solution and mixed thoroughly. Uncomplexed thallium(III) is then precipitated by the addition of an ammonia solution and diluted to 20 ml. Required amount of this mixture is centrifuged. The beta activity of the supernatant aliquot is measured using a GM counter. Quantitative determination of Tl(III) in the range of 1-10 μM can be carried out. The interference of cations such as Au(III), iron(III), Ga(III) can be eliminated by pretreatment of the Tl(III) solution before carrying out radiometric titration. The results obtained are reproducible and accurate to +-3%. (T.I.)

  13. Lidar measurements of boundary layer depolarization and CCSEM-EDX compositional analysis of airborne particles on collocated passive samplers throughout the forest canopy during the 2016 airborne pollen season at UMBS, Pellston, MI

    Wozniak, M. C.; Steiner, A.; Ault, A. P.; Kort, E. A.; Lersch, T.; Casuccio, G.

    2017-12-01

    Observations of airborne pollen are typically made with volumetric samplers that obtain a time-averaged pollen concentration at a single point. While spatial variations in surface pollen concentrations may be known with these samplers given multiple sampling sites, real-time boundary layer transport of pollen grains cannot be determined except by particle dispersion or tracer transport models. Recently, light detection and ranging (lidar) techniques, such as depolarization, have been used to measure pollen transport and optical properties throughout the boundary layer over time. Here, we use a ground-based micro-pulse lidar (MPL) to observe boundary layer vertical profiles before, during and after the peak anemophilous (wind-driven) pollen season. The lidar depolarization ratio is measured in tandem with the normalized R-squared backscatter (NRB) intensity to determine the contribution of aspherical particles to the scatterers present throughout the boundary layer. Measurements are taken from April 15 - July 12, 2016 at the University of Michigan Biological Station (UMBS) PROPHET outdoor research lab and tower within a largely forested region. UMBS is dominated by Acer rubrum, Betula papyrifera, Pinus resinosa, Quercus rubra and Pinus strobus, all of which began flowering on 4/19, 5/3, 5/25, 5/25 and 6/14, respectively. Temperature, relative humidity and wind speed measured on site determine daytime conditions conducive to pollen dispersion from flowers. Lidar depolarization ratios between 0.08-0.14 and higher are observed in the daytime boundary layer on days shortly after the flowering dates of the aforementioned species, elevated above the background level of 0.06 or less. Lidar observations are supplemented with aerosol compositional analysis determined by computer-controlled scanning electron microscopy and energy-dispersive X-ray spectroscopy (CCSEM-EDX) on passive sampler data from below, within and above the forest canopy at PROPHET tower. Particles are

  14. Retrieval of effective cloud field parameters from radiometric data

    Paulescu, Marius; Badescu, Viorel; Brabec, Marek

    2017-06-01

    Clouds play a key role in establishing the Earth's climate. Real cloud fields are very different and very complex in both morphological and microphysical senses. Consequently, the numerical description of the cloud field is a critical task for accurate climate modeling. This study explores the feasibility of retrieving the effective cloud field parameters (namely the cloud aspect ratio and cloud factor) from systematic radiometric measurements at high frequency (measurement is taken every 15 s). Two different procedures are proposed, evaluated, and discussed with respect to both physical and numerical restrictions. None of the procedures is classified as best; therefore, the specific advantages and weaknesses are discussed. It is shown that the relationship between the cloud shade and point cloudiness computed using the estimated cloud field parameters recovers the typical relationship derived from measurements.

  15. The radiometric industries of the countries of the European Community

    Roeper, Burkhardt

    1975-01-01

    The economic development of the radiometric industries in the EEC and the USA since 1960 is studied on the basis of sales statistics. The study covers the supply and the use of radioisotopes, the application of radiometric techniques, the scope and the development of the foreign trade as well as the structure of the firms concerned. The future need for radiometric apparatus is estimated as regards radiation protection, laboratories, industry, nuclear power plants and medicine

  16. Advances in High Energy Solid-State 2-micron Laser Transmitter Development for Ground and Airborne Wind and CO2 Measurements

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Chen, Songsheng; Kavaya, Michael J.; Trieu, Bo; Bai, Yingxin; Petzar, Paul; Modlin, Edward A.; Koch, Grady; hide

    2010-01-01

    Sustained research efforts at NASA Langley Research Center (LaRC) during last fifteen years have resulted in a significant advancement in 2-micron diode-pumped, solid-state laser transmitter for wind and carbon dioxide measurement from ground, air and space-borne platform. Solid-state 2-micron laser is a key subsystem for a coherent Doppler lidar that measures the horizontal and vertical wind velocities with high precision and resolution. The same laser, after a few modifications, can also be used in a Differential Absorption Lidar (DIAL) system for measuring atmospheric CO2 concentration profiles. Researchers at NASA Langley Research Center have developed a compact, flight capable, high energy, injection seeded, 2-micron laser transmitter for ground and airborne wind and carbon dioxide measurements. It is capable of producing 250 mJ at 10 Hz by an oscillator and one amplifier. This compact laser transmitter was integrated into a mobile trailer based coherent Doppler wind and CO2 DIAL system and was deployed during field measurement campaigns. This paper will give an overview of 2-micron solid-state laser technology development and discuss results from recent ground-based field measurements.

  17. Radiometric microassay for ornithine decarboxylase

    Maderdrut, J L; Oppenheim, R W [North Carolina Univ., Chapel Hill (USA). School of Medicine

    1978-01-01

    A simple method for purifying (/sup 3/H)L-ornithine and incubation conditions suitable for estimating L-ornithine decarboxylase activity are described. Routine and recycle cation exchange procedures for separating putrescine from ornithine are outlined. Blanks using the routine cation exchange method average approx. 0.04% of the radioactivity contained in the substrate; product recovery is approx. 94%. The L-ornithine decarboxylase assay is proportional to time for at least 8 h. The relationship between substrate purity and the sensitivity of the cation exchange procedures is assessed. Radiochemical purity is the critical determinant of sensitivity for recycled assays. The cation exchange method is compared with the commonly used CO/sub 2/-trapping method. The cation exchange method is more specific and approximately three orders of magnitude more sensitive than the CO/sub 2/-trapping method. L-ornithine decarboxylase activity can be measured reliably in samples of embryonic neural tissues having wet-weights of approx. 1 ..mu..g. L-ornithine decarboxylase activity in the lumbar spinal cord of the chick embryo decreases 25-30 fold from day 5 to day 18 of embryonic development. A cation exchange procedure for estimating L-lysine decarboxylase activity is also described. Failure to detect L-lysine decarboxylase activity in the chick embryo lumbar spinal cord is contrasted with the previous report of high cadaverine levels in chick embryos.

  18. Accelerator physics and radiometric properties of superconducting wavelength shifters

    Scheer, Michael

    2008-01-01

    Subject of this thesis is the operation of wave-length shifters at electron storage rings and their use in radiometry. The basic aspects of the radiometry, the technical requirements, the influence of wave-length shifters on the storage ring, and results of first measurements are presented for a device installed at BESSY. Most of the calculations are carried out by the program WAVE, which has been developed within this thesis. WAVE allows to calculate the synchrotron radiation spectra of wavelength shifters within an relative uncertainty of 1/100000. The properties of wave-length shifters in terms of accelerator physics as well as a generating function for symplectic tracking calculations can also be calculated by WAVE. The later was implemented in the tracking code BETA to investigate the influence of insertion devices on the dynamic aperture and emittance of the storage ring. These studies led to the concept of alternating low- and high-beta-sections at BESSY-II, which allow to operate superconducting insertion devices without a significant distortion of the magnetic optics. To investigate the experimental aspects of the radiometry at wave-length shifters, a program based on the Monte-Carlo-code GEANT4 has been developed. It allows to simulate the radiometrical measurements and the absorption properties of detectors. With the developed codes first radiometrical measurements by the PTB have been analysed. A comparison of measurements and calculations show a reasonable agreement with deviations of about five percent in the spectral range of 40-60 keV behind a 1-mm-Cu filter. A better agreement was found between 20 keV and 80 keV without Cu filter. In this case the measured data agreed within a systematic uncertainty of two percent with the results of the calculations. (orig.)

  19. Classification of sea ice types with single-band (33.6 GHz) airborne passive microwave imagery

    Eppler, Duane T.; Farmer, L. Dennis; Lohanick, Alan W.; Hoover, Mervyn

    1986-09-01

    During March 1983 extensive high-quality airborne passive Ka band (33.6 GHz) microwave imagery and coincident high-resolution aerial photography were obtained of ice along a 378-km flight line in the Beaufort Sea. Analysis of these data suggests that four classes of winter surfaces can be distinguished solely on the basis of 33.6-GHz brightness temperature: open water, frazil, old ice, and young/first-year ice. New ice (excluding frazil) and nilas display brightness temperatures that overlap the range of temperatures characteristic of old ice and, to a lesser extent, young/first-year ice. Scenes in which a new ice or nilas are present in appreciable amounts are subject to substantial errors in classification if static measures of Ka band radiometric brightness temperature alone are considered. Textural characteristics of nilas and new ice, however, differ significantly from textural features characteristic of other ice types and probably can be used with brightness temperature data to classify ice type in high-resolution single-band microwave images. In any case, open water is radiometrically the coldest surface observed in any scene. Lack of overlap between brightness temperatures characteristic of other surfaces indicates that estimates of the areal extent of open water based on only 33.6-GHz brightness temperatures are accurate.

  20. Overview of Ground Air Quality Measurements and Their Links to Airborne, Remote Sensing and Model Studies during the KORUS-AQ Campaign

    Lee, G.; Ahn, J. Y.; Chang, L. S.; Kim, J.; Park, R.

    2017-12-01

    During the KORUS-AQ, extensive sets of chemical measurements for reactive gases and aerosol species were made at 3 major sites on upwind island (Baengyeong Island), urban (Olympic Park in Seoul) and downwind rural forest location (Taewha Forest). Also, intensive aerosol size and composition observations from 5 NIER super sites, 3 NIMR monitoring sites, and 5 other university sites were currently facilitated in the KORUS-AQ data set. In addition, air quality criteria species data from 264 nation-wide ground monitoring sites with 5 minute temporal resolution during the whole campaign period were supplemented to cover mostly in densely populated urban areas, but sparsely in rural areas. The specific objectives of these ground sites were to provide highly comprehensive data set to coordinate the close collaborations among other research platforms including airborne measurements, remote sensing, and model studies. The continuous measurements at ground sites were well compared with repetitive low-level aircraft observations of NASA's DC-8 over Olympic Park and Taewha Forest site. Similarly, many ground measurements enabled the validation of chemical transport models and the remote sensing observations from ground and NASA's King Air. The observed results from inter-comparison studies in many reactive gases and aerosol compositions between different measurement methods and platforms will be presented. Compiling data sets from ground sites, source-wise analysis for ozone and aerosol, their in-situ formations, and transport characteristics by local/regional circulation will be discussed, too.

  1. Airborne radioiodine species sampler and it's application for measuring removal efficiencies of large charcoal adsorbers for ventilation exhaust air

    Emel, D.; Hetzer, D.; Pelletier, C.A.; Barefoot, E.D.; Cline, J.E.

    1976-01-01

    A program, sponsored by the Electric Power Research Institute, is underway to determine the chemical species of radioiodine coming from LWR power plants and their persistence in the nearby environment. In support of this program, an airborne radioiodine sampler, developed and used by the AEC was modified and tested. This sampler consists of five components. The components are: (1) a particulate filter, (2) CdI 2 on a matrix of chromosorb-P to retain I 2 , (3) 4-Iodophenol on a matrix of activated alumina to retain HOI, (4) silver exchanged molecular sieve-13X to retain organic iodides, and (5) impregnated charcoal to serve as a control. The AEC sampler has not been proof-tested for periods over 48 hours or for flow rates above 0.10 l/s. For maximum sensitivity, a sampler is required to be used for periods of one to two weeks and at a flow rate giving a bed residence time of 0.1 sec. The AEC sampler was scaled up in size to attain an air sampling rate of 0.9 l/s. Each media for this sampler (except the particulate filter) was tested in the laboratory for retention of the iodine species; I 2 , Organic, and HOI. The tests were conducted at typical conditions observed at the main iodine release points at nuclear power plants. Confirmatory tests were run at operating nuclear power plants. The test results showed that under normal plant conditions the sampler could be operated at flow rates up to 0.80 l/s and differentiate the iodine species I 2 , HOI, and CH 3 I. The retention efficiencies of each media for its specie of radioiodine were found to be: I 2 on CdI 2 - 87 +- 5%, HOI on IPH 94 +- 4%, and CH 3 I on Ag 13-X or KI charcoal 99 +- 1%

  2. Optical Imaging and Radiometric Modeling and Simulation

    Ha, Kong Q.; Fitzmaurice, Michael W.; Moiser, Gary E.; Howard, Joseph M.; Le, Chi M.

    2010-01-01

    OPTOOL software is a general-purpose optical systems analysis tool that was developed to offer a solution to problems associated with computational programs written for the James Webb Space Telescope optical system. It integrates existing routines into coherent processes, and provides a structure with reusable capabilities that allow additional processes to be quickly developed and integrated. It has an extensive graphical user interface, which makes the tool more intuitive and friendly. OPTOOL is implemented using MATLAB with a Fourier optics-based approach for point spread function (PSF) calculations. It features parametric and Monte Carlo simulation capabilities, and uses a direct integration calculation to permit high spatial sampling of the PSF. Exit pupil optical path difference (OPD) maps can be generated using combinations of Zernike polynomials or shaped power spectral densities. The graphical user interface allows rapid creation of arbitrary pupil geometries, and entry of all other modeling parameters to support basic imaging and radiometric analyses. OPTOOL provides the capability to generate wavefront-error (WFE) maps for arbitrary grid sizes. These maps are 2D arrays containing digital sampled versions of functions ranging from Zernike polynomials to combination of sinusoidal wave functions in 2D, to functions generated from a spatial frequency power spectral distribution (PSD). It also can generate optical transfer functions (OTFs), which are incorporated into the PSF calculation. The user can specify radiometrics for the target and sky background, and key performance parameters for the instrument s focal plane array (FPA). This radiometric and detector model setup is fairly extensive, and includes parameters such as zodiacal background, thermal emission noise, read noise, and dark current. The setup also includes target spectral energy distribution as a function of wavelength for polychromatic sources, detector pixel size, and the FPA s charge

  3. Development of a portable ambient temperature radiometric assaying instrument

    Lavietes, A.D.; McQuaid, J.H.; Ruhter, W.D.; Paulus, T.J.

    1995-01-01

    There is a strong need for portable radiometric instrumentation that can accurately confirm the presence of nuclear materials and allow isotopic analysis of radionuclides in the field. To fulfill this need, the authors are developing a hand-held, non-cryogenic, low-power gamma- and X-ray measurement and analysis instrument that can both search and then accurately verify the presence of nuclear materials. The authors report on the use of cadmium zinc telluride detectors, signal processing electronics, and the new field-portable instrument based on the MicroNOMAD Multichannel Analyzer from EG and G ORTEC. They will also describe the isotopic analysis that allows uranium enrichment measurements to be made accurately in the field. The benefits of this work are realized in a wide spectrum of applications that include Arms Control, Nuclear Safeguards, Environmental Management, Emergency Response, and Treaty Verification

  4. Airborne geoid determination

    Forsberg, René; Olesen, Arne Vestergaard; Bastos, L.

    2000-01-01

    Airborne geoid mapping techniques may provide the opportunity to improve the geoid over vast areas of the Earth, such as polar areas, tropical jungles and mountainous areas, and provide an accurate "seam-less" geoid model across most coastal regions. Determination of the geoid by airborne methods...... relies on the development of airborne gravimetry, which in turn is dependent on developments in kinematic GPS. Routine accuracy of airborne gravimetry are now at the 2 mGal level, which may translate into 5-10 cm geoid accuracy on regional scales. The error behaviour of airborne gravimetry is well......-suited for geoid determination, with high-frequency survey and downward continuation noise being offset by the low-pass gravity to geoid filtering operation. In the paper the basic principles of airborne geoid determination are outlined, and examples of results of recent airborne gravity and geoid surveys...

  5. Radiometric survey in sampling areas of Itataia mine ore and radiometric monitoring in Itataia project sites

    1982-07-01

    This radiometric survey was done by CDTN, in Itataia sites, on July/82 and it aimed fundamentally to evaluate local radiological conditions, as for aspect of occupational radiation protection. Besides of results obtained, this report has informations of general aspects that ought to serve as subsidies for elaboration of radiological protection program of local. (author) [pt

  6. Correcting for static shift of magnetotelluric data with airborne electromagnetic measurements: a case study from Rathlin Basin, Northern Ireland

    R. Delhaye

    2017-05-01

    Full Text Available Galvanic distortions of magnetotelluric (MT data, such as the static-shift effect, are a known problem that can lead to incorrect estimation of resistivities and erroneous modelling of geometries with resulting misinterpretation of subsurface electrical resistivity structure. A wide variety of approaches have been proposed to account for these galvanic distortions, some depending on the target area, with varying degrees of success. The natural laboratory for our study is a hydraulically permeable volume of conductive sediment at depth, the internal resistivity structure of which can be used to estimate reservoir viability for geothermal purposes; however, static-shift correction is required in order to ensure robust and precise modelling accuracy.We present here a possible method to employ frequency–domain electromagnetic data in order to correct static-shift effects, illustrated by a case study from Northern Ireland. In our survey area, airborne frequency domain electromagnetic (FDEM data are regionally available with high spatial density. The spatial distributions of the derived static-shift corrections are analysed and applied to the uncorrected MT data prior to inversion. Two comparative inversion models are derived, one with and one without static-shift corrections, with instructive results. As expected from the one-dimensional analogy of static-shift correction, at shallow model depths, where the structure is controlled by a single local MT site, the correction of static-shift effects leads to vertical scaling of resistivity–thickness products in the model, with the corrected model showing improved correlation to existing borehole wireline resistivity data. In turn, as these vertical scalings are effectively independent of adjacent sites, lateral resistivity distributions are also affected, with up to half a decade of resistivity variation between the models estimated at depths down to 2000 m. Simple estimation of differences in bulk

  7. Airborne monitoring system

    Kadmon, Y.; Gabovitch, A.; Tirosh, D.; Ellenbogen, M.; Mazor, T.; Barak, D.

    1997-01-01

    A complete system for tracking, mapping, and performing a composition analysis of a radioactive plume and contaminated area was developed at the NRCN. The system includes two major units : An airborne unit for monitoring and a ground station for analyzing. The airborne unit is mounted on a helicopter and includes file following. Four radiation sensor, two 2'' x 2'' Nal (Tl) sensors horizontally separated by lead shield for mapping and spectroscopy, and two Geiger Mueller (GM) tubes as part of the safety system. A multichannel analyzer card is used for spectroscopy. A navigation system, based on GPS and a barometric altitude meter, is used to locate the plume or ground data. The telemetry system, consisting of a transceiver and a modem, transfers all the data in real time to the ground station. An industrial PC (Field Works) runs a dedicated C++ Windows application to manage the acquired data. An independent microprocessor based backup system includes a recorder, display, and key pad. The ground station is based on an industrial PC, a telemetry system, a color printer and a modem to communicate with automatic meteorology stations in the relevant area. A special software controls the ground station. Measurement results are analyzed in the ground station to estimate plume parameters including motion, location, size, velocity, and perform risk assessment. (authors)

  8. Analysis of the radiometric survey during the Argonauta reactor operation

    Oliveira, Eara de S.L.; Cardozo, Katia K.M.; Silva, Joao Carlos P.; Santos, Joao Regis dos

    2013-01-01

    The Argonaut reactor at the Institute of Nuclear Engineering-IEN/CNEN, operates normally, the powers between 1.7 and 340 W on neutrongraphy procedures, production of radionuclides and experimental reactor physics lessons to postgraduate courses. The doses from neutrons and gamma radiation are measured when the reactor is critical, inside the reactor hall and surrounding regions. A study of the data obtained was performed to evaluate the daily need of this survey in the reactor hall. Taking into account the principle ALARA, which aims to optimize and minimize the dose received by the individual, we propose, in this work, through an analysis of the acquired data in occupational radiometric surveys, a reformulation of the area monitoring routine practiced by the team of radiological protection of the Institute of Nuclear Engineering - IEN/CNEN-RJ, whereas other monitoring routines regarding the radiological protection are also applied in the routine of the reactor. The operations under review occurred with the reactor operating 340 W power at intervals of 60, 120 and 180 minutes, in monitoring points in controlled areas, supervised and free. The results showed significant dose values in the output of the J-Channel 9 when the operation occurs with this open. With 180 minutes of operation, the measured values of dose rate were lower than the values at 60 min and 120 operations min. At the point in the supervised area, offsite to the reactor hall, situated in the direction of the J-Channel 9, the value reduces more than 14% in any operating time in relation to the dose rate measured at the point opposite the canal. There is a 50% reduction in the dose rates for operations with and J-9 closed. The results suggest a new frequency of radiometric survey whose mode of operation is maintained in similar conditions, since combined with other relevant practices of radiation protection

  9. Application of microcomputer to X-ray radiometric ore separation

    Neverov, A.D.; Aleksandrov, P.S.; Kotler, N.I.

    1988-01-01

    The practical use of microcomputers as universal means for converting information for solving applied problems of X-ray radiometric ore separation method is considered. Laboratory tests of two metals - tungsten and tin manifested high efficiency of the developed system. X-ray radiometric separator software is developed

  10. A simple radiometric in vitro assay for acetylcholinesterase inhibitors

    Guilarte, T.R.; Burns, H.D.; Dannals, R.F.; Wagner, H.N. Jr.

    1983-01-01

    A radiometric method for screening acetylcholinesterase inhibitors has been described. The method is based on the production of [ 14 C]carbon dioxide from the hydrolysis of acetylcholine. The inhibitory concentration at 50% (IC50) values for several known acetylcholinesterase inhibitors were in agreement with literature values. The new radiometric method is simple, inexpensive, and has the potential for automation

  11. New age radiometric ore sorting - the elegant solution

    Gordon, H.P.; Heuer, T.

    2000-01-01

    Radiometric ore sorting technology and application are described in two parts. Part I reviews the history of radiometric sorting in the minerals industry and describes the latest developments in radiometric sorting technology. Part II describes the history, feasibility study and approach used in the application of the new technology at Rossing Uranium Limited. There has been little progress in the field of radiometric sorting since the late 1970s. This has changed with the development of a high capacity radiometric sorter designed to operate on low-grade ore in the +75mm / -300mm size fraction. This has been designed specifically for an application at Rossing. Rossing has a long history in radiometric sorting dating back to 1968 when initial tests were conducted on the Rossing prospect. Past feasibility studies concluded that radiometric sorting would not conclusively reduce the unit cost of production unless sorting was used to increase production levels. The current feasibility study shows that the application of new radiometric sorter technology makes sorting viable without increasing production, and significantly more attractive with increased production. A pilot approach to confirm sorter performance is described. (author)

  12. Field radiometric methods of prospecting and exploration for uranium ores

    Gorbushina, L.V.; Savenko, E.I.; Serdyukova, A.S.

    1978-01-01

    The textbook includes two main chapters which describe gamma- and emanation field radiometric methods. The textbook is intended for geology and geophysics students having training practice in field radiometric methods and is additional to the course of lectures. The textbook can be used in the''Radiometry'' course which is studied in appropriate geological and technical colleges

  13. Use of Radiometric Survey Data for Environmental Study: The Case of Northern Sumatera

    Tjokrokardono, S; Ramadanus; Sustarman, H

    1998-01-01

    The convertion of old radiometric data obtained from former uranium exploration activities in northem sumatra into radiation exposure has been evaluated. The objective of the study is to find an alternative way for cheaper and faster compilation of radiation exposure database for environmental study purposes. The old radiometric data measure from the outcrops has been plotted 1;250.000, 1;100.000, and 1;50.000 map scales. The data are translated into 1;1000.000 map scale before they are converted into 1;1000.000 radiation exposure rate map using a graphic method. The radiation exposure rate in northem sumatera falls between 25 R/hour to 40 R/hour. The benefit offered using this method is that it provides a cheaper and faster production of radiation exposure rate map from old radiometric map. However, the problems arising from such a production is that the radiometric data provide unhomogeneous data distributions and densities among the area. As a conclusion it is recommended to recollect some of the data at designated area using well calibrated SPP2NF and gamma ray spectrometer instruments

  14. Airborne radioactive contamination following aerosol ventilation studies

    Mackie, A.; Hart, G.C.; Ibbett, D.A.; Whitehead, R.J.S.

    1994-01-01

    Lung aerosol ventilation studies may be accompanied by airborne contamination, with subsequent surface contamination. Airborne contamination has been measured prior to, during and following 59 consecutive 99 Tc m -diethylenetriamine pentaacetate (DTPA) aerosol studies using a personal air sampler. Airborne contamination ranging between 0 and 20 330 kBq m -3 has been measured. Airborne contamination increases with degree of patient breathing difficulty. The effective dose equivalent (EDE) to staff from ingested activity has been calculated to be 0.3 μSv per study. This figure is supported by data from gamma camera images of a contaminated staff member. However, surface contamination measurements reveal that 60% of studies exceed maximum permissible contamination limits for the hands; 16% of studies exceed limits for controlled area surfaces. (author)

  15. Trace Gas Measurements from the GeoTASO and GCAS Airborne Instruments: An Instrument and Algorithm Test-Bed for Air Quality Observations from Geostationary Orbit

    Nowlan, C. R.; Liu, X.; Janz, S. J.; Leitch, J. W.; Al-Saadi, J. A.; Chance, K.; Cole, J.; Delker, T.; Follette-Cook, M. B.; Gonzalez Abad, G.; Good, W. S.; Kowalewski, M. G.; Loughner, C.; Pickering, K. E.; Ruppert, L.; Soo, D.; Szykman, J.; Valin, L.; Zoogman, P.

    2016-12-01

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) and the GEO-CAPE Airborne Simulator (GCAS) instruments are pushbroom sensors capable of making remote sensing measurements of air quality and ocean color. Originally developed as test-bed instruments for the Geostationary Coastal and Air Pollution Events (GEO-CAPE) decadal survey, these instruments are now also part of risk reduction for the upcoming Tropospheric Emissions: Monitoring of Pollution (TEMPO) and Geostationary Environment Monitoring Spectrometer (GEMS) geostationary satellite missions, and will provide validation capabilities after the satellite instruments are in orbit. GeoTASO and GCAS flew on two different aircraft in their first intensive air quality field campaigns during the DISCOVER-AQ missions over Texas in 2013 and Colorado in 2014. GeoTASO was also deployed in 2016 during the KORUS-AQ field campaign to make measurements of trace gases and aerosols over Korea. GeoTASO and GCAS collect spectra of backscattered solar radiation in the UV and visible that can be used to derive 2-D maps of trace gas columns below the aircraft at spatial resolutions on the order of 250 x 500 m. We present spatially resolved maps of trace gas retrievals of ozone, nitrogen dioxide, formaldehyde and sulfur dioxide over urban areas and power plants from flights during the field campaigns, and comparisons with data from ground-based spectrometers, in situ monitoring instruments, and satellites.

  16. Airborne Compositae dermatitis

    Christensen, Lars Porskjær; Jakobsen, Henrik Byrial; Paulsen, E.

    1999-01-01

    The air around intact feverfew (Tanacetum parthenium) plants was examined for the presence of airborne parthenolide and other potential allergens using a high-volume air sampler and a dynamic headspace technique. No particle-bound parthenolide was detected in the former. Among volatiles emitted f...... for airborne Compositae dermatitis. Potential allergens were found among the emitted monoterpenes and their importance in airborne Compositae dermatitis is discussed....

  17. ESA CryoVEx 2014 - Airborne ASIRAS radar and laser scanner measurements during 2014 CryoVEx campaign in the Arctic

    Hvidegaard, S. M.; Nielsen, J. E.; Sørensen, L. Sandberg

    the penetration depth of the ASIRAS radar. An opportunity site on the Greenland Ice Sheet was surveyed near Jakobshavn Isbræ. No other ground experiments were coordinated with the CryoVEx campaing on the Greenland Ice Sheet. The CryoVEx 2014 campaign was a success and the processed data is of high quality......This report outlines the airborne field operations with the ESA airborne Ku‐band interferometric radar (ASIRAS), coincident airborne laser scanner (ALS) and vertical photography to acquire data over sea‐ and land ice along validation sites and CryoSat‐2 ground tracks. The airborne campaign...... in the Beaufort Sea lead by US office of Naval Research (ONR) and north of Greenland as a dedicated ESA CryoVEx initiative. In addition, selected CryoSat‐2 ground tracks were under‐flown in the Lincoln Sea from CFS Alert, North of Greenland and Svalbard from St. Nord and Longyearbyen. Several of the flights...

  18. Multiangular L-band Datasets for Soil Moisture and Sea Surface Salinity Retrieval Measured by Airborne HUT-2D Synthetic Aperture Radiometer

    Kainulainen, J.; Rautiainen, K.; Seppänen, J.; Hallikainen, M.

    2009-04-01

    SMOS is the European Space Agency's next Earth Explorer satellite due for launch in 2009. It aims for global monitoring of soil moisture and ocean salinity utilizing a new technology concept for remote sensing: two-dimensional aperture synthesis radiometry. The payload of SMOS is Microwave Imaging Radiometer by Aperture Synthesis, or MIRAS. It is a passive instrument that uses 72 individual L-band receivers for measuring the brightness temperature of the Earth. From each acquisition, i.e. integration time or snapshot, MIRAS provides two-dimensional brightness temperature of the scene in the instrument's field of view. Thus, consecutive snapshots provide multiangular measurements of the target once the instrument passes over it. Depending on the position of the target in instrument's swath, the brightness temperature of the target at incidence angles from zero up to 50 degrees can be measured with one overpass. To support the development MIRAS instrument, its calibration, and soil moisture and sea surface salinity retrieval algorithm development, Helsinki University of Technology (TKK) has designed, manufactured and tested a radiometer which operates at L-band and utilizes the same two-dimensional methodology of interferometery and aperture synthesis as MIRAS does. This airborne instrument, called HUT-2D, was designed to be used on board the University's research aircraft. It provides multiangular measurements of the target in its field of view, which spans up to 30 degrees off the boresight of the instrument, which is pointed to the nadir. The number of independent measurements of each target point depends on the flight speed and altitude. In addition to the Spanish Airborne MIRAS demonstrator (AMIRAS), HUT-2D is the only European airborne synthetic aperture radiometer. This paper presents the datasets and measurement campaigns, which have been carried out using the HUT-2D radiometer and are available for the scientific community. In April 2007 HUT-2D participated

  19. Aerial radiometric and magnetic survey: Bozeman National Topographic Map, Montana

    1979-01-01

    The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the Bozeman National Topographic Map NL12-8 are presented in Volume I and II of this report. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium, and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included also

  20. Aerial radiometric and magnetic survey: Lander National Topographic Map, Wyoming

    1979-01-01

    The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the Lander National Topographic Map NK12-6 are presented. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included also

  1. High-accuracy continuous airborne measurements of greenhouse gases (CO2 and CH4 using the cavity ring-down spectroscopy (CRDS technique

    V. Y. Chow

    2010-03-01

    Full Text Available High-accuracy continuous measurements of greenhouse gases (CO2 and CH4 during the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia phase B campaign in Brazil in May 2009 were accomplished using a newly available analyzer based on the cavity ring-down spectroscopy (CRDS technique. This analyzer was flown without a drying system or any in-flight calibration gases. Water vapor corrections associated with dilution and pressure-broadening effects for CO2 and CH4 were derived from laboratory experiments employing measurements of water vapor by the CRDS analyzer. Before the campaign, the stability of the analyzer was assessed by laboratory tests under simulated flight conditions. During the campaign, a comparison of CO2 measurements between the CRDS analyzer and a nondispersive infrared (NDIR analyzer on board the same aircraft showed a mean difference of 0.22±0.09 ppm for all flights over the Amazon rain forest. At the end of the campaign, CO2 concentrations of the synthetic calibration gases used by the NDIR analyzer were determined by the CRDS analyzer. After correcting for the isotope and the pressure-broadening effects that resulted from changes of the composition of synthetic vs. ambient air, and applying those concentrations as calibrated values of the calibration gases to reprocess the CO2 measurements made by the NDIR, the mean difference between the CRDS and the NDIR during BARCA was reduced to 0.05±0.09 ppm, with the mean standard deviation of 0.23±0.05 ppm. The results clearly show that the CRDS is sufficiently stable to be used in flight without drying the air or calibrating in flight and the water corrections are fully adequate for high-accuracy continuous airborne measurements of CO2 and CH4.

  2. CO measurements from the ACE-FTS satellite instrument: data analysis and validation using ground-based, airborne and spaceborne observations

    C. Clerbaux

    2008-05-01

    Full Text Available The Atmospheric Chemistry Experiment (ACE mission was launched in August 2003 to sound the atmosphere by solar occultation. Carbon monoxide (CO, a good tracer of pollution plumes and atmospheric dynamics, is one of the key species provided by the primary instrument, the ACE-Fourier Transform Spectrometer (ACE-FTS. This instrument performs measurements in both the CO 1-0 and 2-0 ro-vibrational bands, from which vertically resolved CO concentration profiles are retrieved, from the mid-troposphere to the thermosphere. This paper presents an updated description of the ACE-FTS version 2.2 CO data product, along with a comprehensive validation of these profiles using available observations (February 2004 to December 2006. We have compared the CO partial columns with ground-based measurements using Fourier transform infrared spectroscopy and millimeter wave radiometry, and the volume mixing ratio profiles with airborne (both high-altitude balloon flight and airplane observations. CO satellite observations provided by nadir-looking instruments (MOPITT and TES as well as limb-viewing remote sensors (MIPAS, SMR and MLS were also compared with the ACE-FTS CO products. We show that the ACE-FTS measurements provide CO profiles with small retrieval errors (better than 5% from the upper troposphere to 40 km, and better than 10% above. These observations agree well with the correlative measurements, considering the rather loose coincidence criteria in some cases. Based on the validation exercise we assess the following uncertainties to the ACE-FTS measurement data: better than 15% in the upper troposphere (8–12 km, than 30% in the lower stratosphere (12–30 km, and than 25% from 30 to 100 km.

  3. High-accuracy continuous airborne measurements of greenhouse gases (CO2 and CH4) using the cavity ring-down spectroscopy (CRDS) technique

    Chen, H.; Winderlich, J.; Gerbig, C.; Hoefer, A.; Rella, C. W.; Crosson, E. R.; van Pelt, A. D.; Steinbach, J.; Kolle, O.; Beck, V.; Daube, B. C.; Gottlieb, E. W.; Chow, V. Y.; Santoni, G. W.; Wofsy, S. C.

    2010-03-01

    High-accuracy continuous measurements of greenhouse gases (CO2 and CH4) during the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) phase B campaign in Brazil in May 2009 were accomplished using a newly available analyzer based on the cavity ring-down spectroscopy (CRDS) technique. This analyzer was flown without a drying system or any in-flight calibration gases. Water vapor corrections associated with dilution and pressure-broadening effects for CO2 and CH4 were derived from laboratory experiments employing measurements of water vapor by the CRDS analyzer. Before the campaign, the stability of the analyzer was assessed by laboratory tests under simulated flight conditions. During the campaign, a comparison of CO2 measurements between the CRDS analyzer and a nondispersive infrared (NDIR) analyzer on board the same aircraft showed a mean difference of 0.22±0.09 ppm for all flights over the Amazon rain forest. At the end of the campaign, CO2 concentrations of the synthetic calibration gases used by the NDIR analyzer were determined by the CRDS analyzer. After correcting for the isotope and the pressure-broadening effects that resulted from changes of the composition of synthetic vs. ambient air, and applying those concentrations as calibrated values of the calibration gases to reprocess the CO2 measurements made by the NDIR, the mean difference between the CRDS and the NDIR during BARCA was reduced to 0.05±0.09 ppm, with the mean standard deviation of 0.23±0.05 ppm. The results clearly show that the CRDS is sufficiently stable to be used in flight without drying the air or calibrating in flight and the water corrections are fully adequate for high-accuracy continuous airborne measurements of CO2 and CH4.

  4. Methodology for high-throughput field phenotyping of canopy temperature using airborne thermography

    David Matthew Deery

    2016-12-01

    Full Text Available Lower canopy temperature (CT, resulting from increased stomatal conductance, has been associated with increased yield in wheat. Historically, CT has been measured with hand-held infrared thermometers. Using the hand-held CT method on large field trials is problematic, mostly because measurements are confounded by temporal weather changes during the time requiredto measure all plots. The hand-held CT method is laborious and yet the resulting heritability low, thereby reducing confidence in selection in large scale breeding endeavours.We have developed a reliable and scalable crop phenotyping method for assessing CT in large field experiments. The method involves airborne thermography from a manned helicopter using a radiometrically-calibrated thermal camera. Thermal image data is acquired from large experiments in the order of seconds, thereby enabling simultaneous measurement of CT on potentially 1,000s of plots. Effects of temporal weather variation when phenotyping large experiments using hand-held infrared thermometers are therefore reduced. The method is designed for cost-effective and large-scale use by the non-technical user and includes custom-developed software for data processing to obtain CT data on a single-plot basis for analysis.Broad-sense heritability was routinely greater than 0.50, and as high as 0.79, for airborne thermography CT measured near anthesis on a wheat experiment comprising 768 plots of size 2 x 6 m. Image analysis based on the frequency distribution of temperature pixels to remove the possible influence of background soil did not improve broad-sense heritability. Total imageacquisition and processing time was ca. 25 min and required only one person (excluding the helicopter pilot. The results indicate the potential to phenotype CT on large populations in genetics studies or for selection within a plant breeding program.

  5. Wind field measurement in the nonprecipitous regions surrounding storms by an airborne pulsed Doppler lidar system, appendix A

    Bilbro, J. W.; Vaughan, W. W.

    1980-01-01

    Coherent Doppler lidar appears to hold great promise in contributing to the basic store of knowledge concerning flow field characteristics in the nonprecipitous regions surrounding severe storms. The Doppler lidar, through its ability to measure clear air returns, augments the conventional Doppler radar system, which is most useful in the precipitous regions of the storm. A brief description of the Doppler lidar severe storm measurement system is provided along with the technique to be used in performing the flow field measurements. The application of the lidar is addressed, and the planned measurement program is outlined.

  6. Data processing of remotely sensed airborne hyperspectral data using the Airborne Processing Library (APL): Geocorrection algorithm descriptions and spatial accuracy assessment

    Warren, Mark A.; Taylor, Benjamin H.; Grant, Michael G.; Shutler, Jamie D.

    2014-03-01

    Remote sensing airborne hyperspectral data are routinely used for applications including algorithm development for satellite sensors, environmental monitoring and atmospheric studies. Single flight lines of airborne hyperspectral data are often in the region of tens of gigabytes in size. This means that a single aircraft can collect terabytes of remotely sensed hyperspectral data during a single year. Before these data can be used for scientific analyses, they need to be radiometrically calibrated, synchronised with the aircraft's position and attitude and then geocorrected. To enable efficient processing of these large datasets the UK Airborne Research and Survey Facility has recently developed a software suite, the Airborne Processing Library (APL), for processing airborne hyperspectral data acquired from the Specim AISA Eagle and Hawk instruments. The APL toolbox allows users to radiometrically calibrate, geocorrect, reproject and resample airborne data. Each stage of the toolbox outputs data in the common Band Interleaved Lines (BILs) format, which allows its integration with other standard remote sensing software packages. APL was developed to be user-friendly and suitable for use on a workstation PC as well as for the automated processing of the facility; to this end APL can be used under both Windows and Linux environments on a single desktop machine or through a Grid engine. A graphical user interface also exists. In this paper we describe the Airborne Processing Library software, its algorithms and approach. We present example results from using APL with an AISA Eagle sensor and we assess its spatial accuracy using data from multiple flight lines collected during a campaign in 2008 together with in situ surveyed ground control points.

  7. JPSS-1 VIIRS Pre-Launch Radiometric Performance

    Oudrari, Hassan; McIntire, Jeff; Xiong, Xiaoxiong; Butler, James; Efremova, Boryana; Ji, Jack; Lee, Shihyan; Schwarting, Tom

    2015-01-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) on-board the first Joint Polar Satellite System (JPSS) completed its sensor level testing on December 2014. The JPSS-1 (J1) mission is scheduled to launch in December 2016, and will be very similar to the Suomi-National Polar-orbiting Partnership (SNPP) mission. VIIRS instrument was designed to provide measurements of the globe twice daily. It is a wide-swath (3,040 kilometers) cross-track scanning radiometer with spatial resolutions of 370 and 740 meters at nadir for imaging and moderate bands, respectively. It covers the wavelength spectrum from reflective to long-wave infrared through 22 spectral bands [0.412 microns to 12.01 microns]. VIIRS observations are used to generate 22 environmental data products (EDRs). This paper will briefly describe J1 VIIRS characterization and calibration performance and methodologies executed during the pre-launch testing phases by the independent government team, to generate the at-launch baseline radiometric performance, and the metrics needed to populate the sensor data record (SDR) Look-Up-Tables (LUTs). This paper will also provide an assessment of the sensor pre-launch radiometric performance, such as the sensor signal to noise ratios (SNRs), dynamic range, reflective and emissive bands calibration performance, polarization sensitivity, bands spectral performance, response-vs-scan (RVS), near field and stray light responses. A set of performance metrics generated during the pre-launch testing program will be compared to the SNPP VIIRS pre-launch performance.

  8. Measuring radiant emissions from entire prescribed fires with ground, airborne and satellite sensors - RxCADRE 2012

    Matthew B. Dickinson; Andrew T. Hudak; Thomas Zajkowski; E. Louise Loudermilk; Wilfrid Schroeder; Luke Ellison; Robert L. Kremens; William Holley; Otto Martinez; Alexander Paxton; Benjamin C. Bright; Joseph O' Brien; Ben Hornsby; Charles Ichoku; Jason Faulring; Aaron Gerace; David Peterson; Joseph Mauceri

    2016-01-01

    Characterising radiation from wildland fires is an important focus of fire science because radiation relates directly to the combustion process and can be measured across a wide range of spatial extents and resolutions. As part of a more comprehensive set of measurements collected during the 2012 Prescribed Fire Combustion and Atmospheric Dynamics Research (RxCADRE)...

  9. Calibration of column-averaged CH4 over European TCCON FTS sites with airborne in-situ measurements

    Geibel, M. C.; Messerschmidt, J.; Gerbig, C.; Blumenstock, T.; Chen, H.; Hase, F.; Kolle, O.; Lavric, J. V.; Notholt, J.; Palm, M.; Rettinger, M.; Schmidt, Martina; Sussmann, R.; Warneke, T.; Feist, D. G.

    2012-01-01

    In September/October 2009, six European ground-based Fourier Transform Spectrometers (FTS) of the Total Carbon Column Observation Network (TCCON) were calibrated for the first time using aircraft measurements. The campaign was part of the Infrastructure for Measurement of the European Carbon Cycle

  10. Enhanced radiometric detection of Mycobacterium paratuberculosis by using filter-concentrated bovine fecal specimens

    Collins, M.T.; Kenefick, K.B.; Sockett, D.C.; Lambrecht, R.S.; McDonald, J.; Jorgensen, J.B.

    1990-01-01

    A commercial radiometric medium, BACTEC 12B, was modified by addition of mycobactin, egg yolk suspension, and antibiotics (vancomycin, amphotericin B, and nalidixic acid). Decontaminated bovine fecal specimens were filter concentrated by using 3-microns-pore-size, 13-mm-diameter polycarbonate filters, and the entire filter was placed into the radiometric broth. Comparison of the radiometric technique with conventional methods on 603 cattle from 9 Mycobacterium paratuberculosis-infected herds found that of 75 positive specimens, the radiometric technique detected 92% while conventional methods detected 60% (P less than 0.0005). Only 3.9% of radiometric cultures were contaminated. To measure the effect of filter concentration of specimens on the detection rate, 5 cattle with minimal and 5 with moderate ileum histopathology were sampled weekly for 3 weeks. M. paratuberculosis was detected in 33.3% of nonfiltered specimens and 76.7% of filtered specimens (P less than 0.005). Detection rates were directly correlated with the severity of disease, and the advantage of specimen concentration was greatest on fecal specimens from cattle with low-grade infections. Detection times were also correlated with infection severity: 13.4 +/- 5.9 days with smear-positive specimens, 27.9 +/- 8.7 days with feces from cows with typical subclinical infections, and 38.7 +/- 3.8 days with fecal specimens from cows with low-grade infections. Use of a cocktail of vancomycin, amphotericin B, and nalidixic acid for selective suppression of nonmycobacterial contaminants was better than the commercial product PANTA (Becton Dickinson Microbiologic Systems, Towson, Md.) only when specimens contained very low numbers of M. paratuberculosis

  11. Radiometric sorting of Rio Algom uranium ore

    Cristovici, M.A.

    1983-11-01

    An ore sample of about 0.2 percent uranium from Quirke Mine was subjected to radiometric sorting by Ore Sorters Limited. Approximately 60 percent of the sample weight fell within the sortable size range: -150 + 25 mm. Rejects of low uranium content ( 2 (2 counts/in 2 ) but only 7.6 percent of the ore, by weight, was discarded. At 0.8-0.9 counts/cm 2 (5-6 counts/in 2 ) a significant amount of rejects was removed (> 25 percent) but the uranium loss was unacceptably high (7.7 percent). Continuation of the testwork to improve the results is proposed by trying to extend the sortable size range and to reduce the amount of fines during crushing

  12. Importance of radiometric survey in radiodiagnosis installationscalculated

    Leyton, Fernando; Alarcon, Luis; Zapata, Victor H.; Ortega, Dulia; Ramirez, Alfredo; Aravena, Gonzalo; Ubeda, Carlos; Oyarzun, Carlos; Inzulza, Alonso

    2005-01-01

    A radiometric survey was conducted in two services of imaging with a total of 7 evaluated radiology rooms. The Quality Control Protocol methodology was used in Radiology ARCAL (Regional Agreement of cooperation for the promotion of nuclear science and technology in Latin America and the Caribbean) XLIX of the International Atomic Energy Agency (IAEA). The effective dose in different positions of interest rates were calculated, from the point of view of radiation protection. All evaluated rooms have rates of effective doses that meet the values limits set in the Protocol ARCAL XLIX, for 82% of the positions evaluated. However operators located in the position A (controlled area) exceed on average 370% with a range of [1-870] the limit proposed by ARCAL XLIX

  13. Radiometric monitoring outdoor municipality Pocinhos-PB

    Cardinalli Araujo Costa, Michelle; Araujo dos Santos Junior, Jose; Dos Santos Amaral, Romilton

    2015-01-01

    Studies on human exposure to terrestrial radionuclides are important for human health. Therefore, this investigation presents aimed at making radiometric dosimetry Pocinhos municipality in the state of Paraiba. Monitoring was performed in 50 points in urban and rural areas Pocinhos. The estimated external effective dose rate in outdoor environments was obtained in triplicate using a portable gamma spectrometer, to 1.0 m away from the Earth's surface and time set acquisition in terms of environmental radiation levels. The values of these dose rates outdoor environments ranging from 0.53 to 3.94 mSv.y -1 . the arithmetic mean was 0.79 mSv.y -1 , which exceeds the value 0.07 mSv.y -1 corresponding to the global average in outdoor environments. In the city, found a higher radioactivity in rural areas that were uninhabited at the time of the survey. (Author)

  14. The MAFF dry cloth collector programme for monitoring airborne radioactivity

    McHugh, J.O.; Smith, B.D.; Hunt, G.J.; Thomas, R.E.G.

    1986-01-01

    The history of the MAFF airborne radioactivity monitoring programme and its current operation using dry cloth collectors are described. The detection system has become well established as a sensitive indicator of airborne radioactivity. Details of collector materials, deployment around the major UK nuclear establishments and procedures for radiometric analysis of cloths are given. Typical results for the period 1980-82 show that at most sites only nuclear weapons fallout was detected. The systems's usefulness is exemplified by its response to the release of I-131 from Sellafield in 1981; this release was of negligible radiological significance but was easily detected. The response of dry cloths to various sources of atmospheric radioactivity and factors affecting collection efficiency are discussed. (author)

  15. Cavity Attenuated Phase Shift (CAPS) Method for Airborne Aerosol Light Extinction Measurement: Instrument Validation and First Results from Field Deployment

    Petzold, A.; Perim de Faria, J.; Berg, M.; Bundke, U.; Freedman, A.

    2015-12-01

    Monitoring the direct impact of aerosol particles on climate requires the continuous measurement of aerosol optical parameters like the aerosol extinction coefficient on a regular basis. Remote sensing and ground-based networks are well in place (e.g., AERONET, ACTRIS), whereas the regular in situ measurement of vertical profiles of atmospheric aerosol optical properties remains still an important challenge in quantifying climate change. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System; www.iagos.org) responds to the increasing requests for long-term, routine in situ observational data by using commercial passenger aircraft as measurement platform. However, scientific instrumentation for the measurement of atmospheric constituents requires major modifications before being deployable aboard in-service passenger aircraft. Recently, a compact and robust family of optical instruments based on the cavity attenuated phase shift (CAPS) technique has become available for measuring aerosol light extinction. While this technique was successfully deployed for ground-based atmospheric measurements under various conditions, its suitability for operation aboard aircraft in the free and upper free troposphere still has to be demonstrated. In this work, the modifications of a CAPS PMex instrument for measuring aerosol light extinction on aircraft, the results from subsequent laboratory tests for evaluating the modified instrument prototype, and first results from a field deployment aboard a research aircraft will be covered. In laboratory studies, the instrument showed excellent agreement (deviation CAPS PMex instrument response within 10% deviation. During the field deployment, aerosol extinction coefficients and associated aerosol size distributions have been measured and will be presented as comparison studies between measured and calculated data.

  16. Aperture area measurement facility

    Federal Laboratory Consortium — NIST has established an absolute aperture area measurement facility for circular and near-circular apertures use in radiometric instruments. The facility consists of...

  17. Sources, Sinks and Chemistry of Volatile Organic Compounds: A Summary of Results from Multiple Airborne, Ship-Based and Surface Measurements

    de Gouw, J. A.; Gilman, J. B.; Goldan, P. D.; Kuster, W. C.; Roberts, J. M.; Veres, P. R.; Warneke, C.; Welsh-Bon, D.

    2009-12-01

    Volatile Organic compounds (VOCs) are emitted from a wide variety of natural and man-made sources. In the atmosphere, VOCs are oxidized on a time scale ranging from minutes to months by reactions with OH, NO3 and ozone, and by photolysis. While the removal of hydrocarbons is well described by these removal processes, the chemical formation and direct emissions of oxygenated VOCs are poorly characterized and understood. VOC oxidation in the atmosphere contributes to the formation of ozone and secondary organic aerosol (SOA). Both species are important ingredients of polluted air and represent a significant radiative forcing to the climate system. We have measured VOCs during several different field studies using both mass spectrometric and gas chromatographic methods. Airborne measurements from the NOAA WP-3D aircraft were carried out along the U.S. West Coast in 2002, in the northeastern U.S. in 2004, in Texas in 2006 and in Alaska in 2008. Ship-based measurements were conducted in the Gulf of Maine in 2002 and 2004, in the Gulf of Mexico in 2006 and in the northern Atlantic in 2008. Surface measurements were made in Beijing in 2005, in Mexico City in 2006 and at Blodgett Forest in 2007. In this presentation we will first make a comparison of the averaged observations between these different field studies. Average altitude profiles, surface mixing ratios and the diurnal variations therein will be compared, which gives a unique and detailed insight into the atmospheric distribution of VOCs. We will next turn to several case studies describing our observations in urban, forest fire and industrial plumes with a special focus on oxygenated VOCs. Insights into the natural sources of oxygenated VOCs from forests and oceans are described. Finally, we will briefly discuss new instrument developments in our laboratory.

  18. Single-particle measurements of bouncing particles and in situ collection efficiency from an airborne aerosol mass spectrometer (AMS) with light-scattering detection

    Liao, Jin; Brock, Charles A.; Murphy, Daniel M.; Sueper, Donna T.; Welti, André; Middlebrook, Ann M.

    2017-10-01

    A light-scattering module was coupled to an airborne, compact time-of-flight aerosol mass spectrometer (LS-AMS) to investigate collection efficiency (CE) while obtaining nonrefractory aerosol chemical composition measurements during the Southeast Nexus (SENEX) campaign. In this instrument, particles scatter light from an internal laser beam and trigger saving individual particle mass spectra. Nearly all of the single-particle data with mass spectra that were triggered by scattered light signals were from particles larger than ˜ 280 nm in vacuum aerodynamic diameter. Over 33 000 particles are characterized as either prompt (27 %), delayed (15 %), or null (58 %), according to the time and intensity of their total mass spectral signals. The particle mass from single-particle spectra is proportional to that derived from the light-scattering diameter (dva-LS) but not to that from the particle time-of-flight (PToF) diameter (dva-MS) from the time of the maximum mass spectral signal. The total mass spectral signal from delayed particles was about 80 % of that from prompt ones for the same dva-LS. Both field and laboratory data indicate that the relative intensities of various ions in the prompt spectra show more fragmentation compared to the delayed spectra. The particles with a delayed mass spectral signal likely bounced off the vaporizer and vaporized later on another surface within the confines of the ionization source. Because delayed particles are detected by the mass spectrometer later than expected from their dva-LS size, they can affect the interpretation of particle size (PToF) mass distributions, especially at larger sizes. The CE, measured by the average number or mass fractions of particles optically detected that had measurable mass spectra, varied significantly (0.2-0.9) in different air masses. The measured CE agreed well with a previous parameterization when CE > 0.5 for acidic particles but was sometimes lower than the minimum parameterized CE of 0.5.

  19. Airborne lidar reflectance measurements at 1.57 μm in support of the A-SCOPE mission for atmospheric CO2

    J. Caron

    2009-11-01

    Full Text Available The characteristics of the lidar reflectance of the Earth's surface is an important issue for the IPDA lidar technique (integrated path differential absorption lidar which is the proposed method for the spaceborne measurement of atmospheric carbon dioxide within the framework of ESA's A-SCOPE project. Both, the absolute reflectance of the ground and its variations have an impact on the measurement sensitivity. The first aspect influences the instrument's signal to noise ratio, the second one can lead to retrieval errors, if the ground reflectance changes are strong on small scales. The investigation of the latter is the main purpose of this study. Airborne measurements of the lidar ground reflectance at 1.57 μm wavelength were performed in Central and Western Europe, including many typical land surface coverages as well as the open sea. The analyses of the data show, that the lidar ground reflectance is highly variable on a wide range of spatial scales. However, by means of the assumption of laser footprints in the order of several tens of meters, as planned for spaceborne systems, and by means of an averaging of the data it was shown, that this specific retrieval error is well below 1 ppm (CO2 column mixing ratio, and so compatible with the sensitivity requirements of spaceborne CO2 measurements. Several approaches for upscaling the data in terms of the consideration of larger laser footprints, compared to the one used here, are shown and discussed. Furthermore, the collected data are compared to MODIS ground reflectance data.

  20. Airborne hyperspectral remote sensing in Italy

    Bianchi, Remo; Marino, Carlo M.; Pignatti, Stefano

    1994-12-01

    The Italian National Research Council (CNR) in the framework of its `Strategic Project for Climate and Environment in Southern Italy' established a new laboratory for airborne hyperspectral imaging devoted to environmental problems. Since the end of June 1994, the LARA (Laboratorio Aereo per Ricerche Ambientali -- Airborne Laboratory for Environmental Studies) Project is fully operative to provide hyperspectral data to the national and international scientific community by means of deployments of its CASA-212 aircraft carrying the Daedalus AA5000 MIVIS (multispectral infrared and visible imaging spectrometer) system. MIVIS is a modular instrument consisting of 102 spectral channels that use independent optical sensors simultaneously sampled and recorded onto a compact computer compatible magnetic tape medium with a data capacity of 10.2 Gbytes. To support