Trace explosives sensor testbed (TESTbed)

Science.gov (United States)

Collins, Greg E.; Malito, Michael P.; Tamanaha, Cy R.; Hammond, Mark H.; Giordano, Braden C.; Lubrano, Adam L.; Field, Christopher R.; Rogers, Duane A.; Jeffries, Russell A.; Colton, Richard J.; Rose-Pehrsson, Susan L.

2017-03-01

A novel vapor delivery testbed, referred to as the Trace Explosives Sensor Testbed, or TESTbed, is demonstrated that is amenable to both high- and low-volatility explosives vapors including nitromethane, nitroglycerine, ethylene glycol dinitrate, triacetone triperoxide, 2,4,6-trinitrotoluene, pentaerythritol tetranitrate, and hexahydro-1,3,5-trinitro-1,3,5-triazine. The TESTbed incorporates a six-port dual-line manifold system allowing for rapid actuation between a dedicated clean air source and a trace explosives vapor source. Explosives and explosives-related vapors can be sourced through a number of means including gas cylinders, permeation tube ovens, dynamic headspace chambers, and a Pneumatically Modulated Liquid Delivery System coupled to a perfluoroalkoxy total-consumption microflow nebulizer. Key features of the TESTbed include continuous and pulseless control of trace vapor concentrations with wide dynamic range of concentration generation, six sampling ports with reproducible vapor profile outputs, limited low-volatility explosives adsorption to the manifold surface, temperature and humidity control of the vapor stream, and a graphical user interface for system operation and testing protocol implementation.

Instrumental concept and preliminary performances of SIFTI: static infrared fourier transform interferometer

Science.gov (United States)

Hébert, Philippe-Jean; Cansot, E.; Pierangelo, C.; Buil, C.; Bernard, F.; Loesel, J.; Trémas, T.; Perrin, L.; Courau, E.; Casteras, C.; Maussang, I.; Simeoni, D.

2017-11-01

The SIFTI (Static Infrared Fourier Transform Interferometer) instrument aims at supporting an important part in a mission for atmospheric pollution sounding from space, by providing high spectral resolution and high Signal to Noise Ratio spectra of the atmosphere. They will allow to resolve tropospheric profiles of ozone (03) and carbon monoxide (C0), especially down to the planetary boundary layer (PBL), an altitude region of very high interest, though poorly monitored to date, for air quality and pollution monitoring. The retrieved profile of ozone, resp. C0, will contain 5 to 7, resp. 2.5 to 4, independent pieces of information. The French space agency CNES (Centre National d'Etudes Spatiales) has proposed and is studying an instrument concept for SIFTI based on a static interferometer, where the needed optical path are generated by a pair of crossed staircase fixed mirrors (replacing the moving reflector of dynamic Fourier transform interferometers like IASI or MIPAS). With the SIFTI design, a very high spectral resolution ( 0.1 cm-1 apodised) is achieved in a very compact optical setup, allowing a large throughput, hence a high SNR. The measurements are performed in the 9.5 μm band for 03 and in the 4.6 μm band for C0. The science return of the sounder can be further increased if an "intelligent pointing" process is implemented. This consists in combining the TIR sounder with a companion TIR imager, providing information on the cloud coverage in the next observed scene. 0nboard, real-time analysis of the IR image is used to command the sounder staring mirror to cloud free areas, which will maximize the probability for probing down to the surface. After the first part of the phase A, the architecture of SIFTI was studied as a trade-off between performance and resource budget. We review the main architecture and functional choices, and their advantages. The preliminary instrument concept is then presented in its main aspects and in terms of main subsystem

Development of a Tethered Formation Flight Testbed for ISS, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The development of a testbed for the development and demonstration of technologies needed by tethered formation flying satellites is proposed. Such a testbed would...

A remote integrated testbed for cooperating objects

CERN Document Server

Dios, Jose Ramiro Martinez-de; Bernabe, Alberto de San; Ollero, Anibal

2013-01-01

Testbeds are gaining increasing relevance in research domains and also in industrial applications. However, very few books devoted to testbeds have been published. To the best of my knowledge no book on this topic has been published. This book is particularly interesting for the growing community of testbed developers. I believe the book is also very interesting for researchers in robot-WSN cooperation.This book provides detailed description of a system that can be considered the first testbed that allows full peer-to-peer interoperability between heterogeneous robots and ubiquitous systems su

Vacuum Nuller Testbed (VNT) Performance, Characterization and Null Control: Progress Report

Science.gov (United States)

Lyon, Richard G.; Clampin, Mark; Petrone, Peter; Mallik, Udayan; Madison, Timothy; Bolcar, Matthew R.; Noecker, M. Charley; Kendrick, Stephen; Helmbrecht, Michael

2011-01-01

Herein we report on the development. sensing and control and our first results with the Vacuum Nuller Testbed to realize a Visible Nulling Coronagraph (VNC) for exoplanet coronagraphy. The VNC is one of the few approaches that works with filled. segmented and sparse or diluted-aperture telescope systems. It thus spans a range of potential future NASA telescopes and could be Hown as a separate instrument on such a future mission. NASA/Goddard Space Flight Center (GSFC) has a well-established effort to develop VNC technologies. and has developed an incremental sequence of VNC testbeds to advance this approach and the enabling technologies associated with it. We discuss the continued development of the vacuum Visible Nulling Coronagraph testbed (VNT). Tbe VNT is an ultra-stable vibration isolated testbed that operates under closed-loop control within a vacuum chamber. It will be used to achieve an incremental sequence of three visible-light nulling milestones with sequentially higher contrasts of 10(sup 8), 10(sup 9) and ideally 10(sup 10) at an inner working angle of 2*lambda/D. The VNT is based on a modified Mach-Zehnder nulling interferometer, with a "W" configuration to accommodate a hex-packed MEMS based deformable mirror, a coherent fiber bundle and achromatic phase shifters. We discuss the initial laboratory results, the optical configuration, critical technologies and the null sensing and control approach.

Vacuum nuller testbed (VNT) performance, characterization and null control: progress report

Science.gov (United States)

Lyon, Richard G.; Clampin, Mark; Petrone, Peter; Mallik, Udayan; Madison, Timothy; Bolcar, Matthew R.; Noecker, M. Charley; Kendrick, Stephen; Helmbrecht, Michael

2011-10-01

Herein we report on the development, sensing and control and our first results with the Vacuum Nuller Testbed to realize a Visible Nulling Coronagraph (VNC) for exoplanet coronagraphy. The VNC is one of the few approaches that works with filled, segmented and sparse or diluted-aperture telescope systems. It thus spans a range of potential future NASA telescopes and could be flown as a separate instrument on such a future mission. NASA/Goddard Space Flight Center (GSFC) has a well-established effort to develop VNC technologies, and has developed an incremental sequence of VNC testbeds to advance this approach and the enabling technologies associated with it. We discuss the continued development of the vacuum Visible Nulling Coronagraph testbed (VNT). The VNT is an ultra-stable vibration isolated testbed that operates under closed-loop control within a vacuum chamber. It will be used to achieve an incremental sequence of three visible-light nulling milestones with sequentially higher contrasts of 108, 109, and ideally 1010 at an inner working angle of 2*λ/D. The VNT is based on a modified Mach-Zehnder nulling interferometer, with a "W" configuration to accommodate a hex-packed MEMS based deformable mirror, a coherent fiber bundle and achromatic phase shifters. We discuss the initial laboratory results, the optical configuration, critical technologies and the null sensing and control approach.

Nuclear Instrumentation and Control Cyber Testbed Considerations – Lessons Learned

Energy Technology Data Exchange (ETDEWEB)

Jonathan Gray; Robert Anderson; Julio G. Rodriguez; Cheol-Kwon Lee

2014-08-01

Abstract: Identifying and understanding digital instrumentation and control (I&C) cyber vulnerabilities within nuclear power plants and other nuclear facilities, is critical if nation states desire to operate nuclear facilities safely, reliably, and securely. In order to demonstrate objective evidence that cyber vulnerabilities have been adequately identified and mitigated, a testbed representing a facility’s critical nuclear equipment must be replicated. Idaho National Laboratory (INL) has built and operated similar testbeds for common critical infrastructure I&C for over ten years. This experience developing, operating, and maintaining an I&C testbed in support of research identifying cyber vulnerabilities has led the Korean Atomic Energy Research Institute of the Republic of Korea to solicit the experiences of INL to help mitigate problems early in the design, development, operation, and maintenance of a similar testbed. The following information will discuss I&C testbed lessons learned and the impact of these experiences to KAERI.

The Expected Impacts of NPOESS Microwave and Infrared Sounder Radiances on Operational Numerical Weather Prediction and Data Assimilation Systems

Science.gov (United States)

Swadley, S. D.; Baker, N.; Derber, J.; Collard, A.; Hilton, F.; Ruston, B.; Bell, W.; Candy, B.; Kleespies, T. J.

2009-12-01

The NPOESS atmospheric sounding functionality will be accomplished using two separate sensor suites, the combined infrared (IR) and microwave (MW) sensor suite (CrIMSS), and the Microwave Imager/Sounder (MIS) instrument. CrIMSS consists of the Cross Track Infrared Sounder (CrIS) and the cross track Advanced Technology Microwave Sounder (ATMS), and is scheduled to fly on the NPOESS Preparatory Project (NPP), and NPOESS operational flight units C1 and C3. The MIS is a conical scanning polarimetric imager and sounder patterned after the heritage WindSat, and DMSP Special Sensor Microwave Imagers and Sounders (SSMI and SSMIS), and is scheduled for flight units C2, C3 and C4. ATMS combines the current operational Advanced Microwave Sounding Unit (AMSU) and the Microwave Humidity Sounder (MHS), but with an additional channel in the 51.76 GHz oxygen absorption region and 3 additional channels in the 165.5 and 183 GHz water vapor absorption band. CrIS is a Fourier Transform Spectrometer and will provide 159 shortwave IR channels, 433 mid-range IR channels, and 713 longwave IR channels. The heritage sensors for CrIS are the NASA Advanced Infrared Sounder (AIRS) and the MetOp-A Infrared Atmospheric Sounding Interferometer (IASI). Both AIRS and IASI are high quality, high spectral resolution sounders which represent a significant improvement in the effective vertical resolution over previous IR sounders. This presentation will give an overview of preparations underway for day-1 monitoring of NPP/NPOESS radiances, and subsequent operational radiance assimilation. These preparations capitalize on experience gained during the pre-launch preparations, sensor calibration/validation and operational assimilation for the heritage sensors. One important step is to use pre-flight sensor channel specifications, noise estimates and knowledge of the antenna patterns, to generate and test proxy NPP/NPOESS sensor observations in existing assimilation systems. Other critical factors for

Tropospheric Carbon Monoxide Measurements from the Scanning High-resolution Interferometer Sounder on 7 September 2000 in Southern Africa during SAFARI 2000

Science.gov (United States)

McMillan, W. W.; McCourt, M. L.; Revercomb, H. E.; Knuteson, R. O.; Christian, T. J.; Doddridge, B. G.; Hobbs, P. V.; Lukovich, P. C.; Novelli, P. C.; Piketh, S. J.

2003-01-01

Retrieved tropospheric carbon monoxide (CO) column densities are presented for more than 9000 spectra obtained by the University of Wisconsin-Madison (UWis) Scanning High-Resolution Interferometer Sounder (SHIS) during a flight on the NASA ER-2 on 7 September 2000 as part of the Southern African Regional Science Initiative (SAFARI 2000) dry season field campaign. Enhancements in tropospheric column CO were detected in the vicinity of a controlled biomass burn in the Timbavati Game Reserve in northeastern South Africa and over the edge of the river of smoke in south central Mozambique. Relatively clean air was observed over the far southern coast of Mozambique. Quantitative comparisons are presented with in situ measurements from five different instruments flying on two other aircraft: the University of Washington Convair-580 (CV) and the South African Aerocommander JRB in the vicinity of the Timbavati fire. Measured tropospheric CO columns (extrapolated from 337 to 100 mb) of 2.1 x 10(exp 18) per square centimeter in background air and up to 1.5 x 10(exp 19) per square centimeter in the smoke plume agree well with SHIS retrieved tropospheric CO columns of (2.3 plus or minus 0.25) x 10(exp 18) per square centimeter over background air near the fire and (1.5 plus or minus 0.35) x 10(exp 19) per square centimeter over the smoke plume. Qualitative comparisons are presented with three other in situ CO profiles obtained by the South African JRA aircraft over Mozambique and northern South Africa showing the influence of the river of smoke.

Visible nulling coronagraphy testbed development for exoplanet detection

Science.gov (United States)

Lyon, Richard G.; Clampin, Mark; Woodruff, Robert A.; Vasudevan, Gopal; Thompson, Patrick; Chen, Andrew; Petrone, Peter; Booth, Andrew; Madison, Timothy; Bolcar, Matthew; Noecker, M. Charley; Kendrick, Stephen; Melnick, Gary; Tolls, Volker

2010-07-01

Three of the recently completed NASA Astrophysics Strategic Mission Concept (ASMC) studies addressed the feasibility of using a Visible Nulling Coronagraph (VNC) as the prime instrument for exoplanet science. The VNC approach is one of the few approaches that works with filled, segmented and sparse or diluted aperture telescope systems and thus spans the space of potential ASMC exoplanet missions. NASA/Goddard Space Flight Center (GSFC) has a well-established effort to develop VNC technologies and has developed an incremental sequence of VNC testbeds to advance the this approach and the technologies associated with it. Herein we report on the continued development of the vacuum Visible Nulling Coronagraph testbed (VNT). The VNT is an ultra-stable vibration isolated testbed that operates under high bandwidth closed-loop control within a vacuum chamber. It will be used to achieve an incremental sequence of three visible light nulling milestones of sequentially higher contrasts of 108, 109 and 1010 at an inner working angle of 2*λ/D and ultimately culminate in spectrally broadband (>20%) high contrast imaging. Each of the milestones, one per year, is traceable to one or more of the ASMC studies. The VNT uses a modified Mach-Zehnder nulling interferometer, modified with a modified "W" configuration to accommodate a hex-packed MEMS based deformable mirror, a coherent fiber bundle and achromatic phase shifters. Discussed will be the optical configuration laboratory results, critical technologies and the null sensing and control approach.

An evaluation of high-resolution interferometer soundings and their use in mesoscale analyses

Science.gov (United States)

Bradshaw, John T.; Fuelberg, Henry E.

1993-01-01

An examination is made of temperature and dewpoint soundings obtained by an airborne prototype of the High-resolution Interferometer Sounder (HIS) on two flight days, to ascertain their error characteristics and their utility in mesoscale analyses. Crude estimates of Bowen ratio were obtained from HIS data using a mixing-line approach; the HIS retrievals indicated that areas of thunderstorm formation were the regions of greatest instability. HIS soundings were also able to detect some of the landscape variability and temperature and humidity fluctuations present.

Conversion of conventional gravitational-wave interferometers into quantum nondemolition interferometers by modifying their input and/or output optics

International Nuclear Information System (INIS)

Kimble, H.J.; Levin, Yuri; Thorne, Kip S.; Matsko, Andrey B.; Vyatchanin, Sergey P.

2002-01-01

The LIGO-II gravitational-wave interferometers (ca. 2006-2008) are designed to have sensitivities near the standard quantum limit (SQL) in the vicinity of 100 Hz. This paper describes and analyzes possible designs for subsequent LIGO-III interferometers that can beat the SQL. These designs are identical to a conventional broad band interferometer (without signal recycling), except for new input and/or output optics. Three designs are analyzed: (i) a squeezed-input interferometer (conceived by Unruh based on earlier work of Caves) in which squeezed vacuum with frequency-dependent (FD) squeeze angle is injected into the interferometer's dark port; (ii) a variational-output interferometer (conceived in a different form by Vyatchanin, Matsko and Zubova), in which homodyne detection with FD homodyne phase is performed on the output light; and (iii) a squeezed-variational interferometer with squeezed input and FD-homodyne output. It is shown that the FD squeezed-input light can be produced by sending ordinary squeezed light through two successive Fabry-Perot filter cavities before injection into the interferometer, and FD-homodyne detection can be achieved by sending the output light through two filter cavities before ordinary homodyne detection. With anticipated technology (power squeeze factor e -2R =0.1 for input squeezed vacuum and net fractional loss of signal power in arm cavities and output optical train ε * =0.01) and using an input laser power I o in units of that required to reach the SQL (the planned LIGO-II power, I SQL ), the three types of interferometer could beat the amplitude SQL at 100 Hz by the following amounts μ≡√(S h )/√(S h SQL ) and with the following corresponding increase V=1/μ 3 in the volume of the universe that can be searched for a given noncosmological source: Squeezed input--μ≅√(e -2R )≅0.3 and V≅1/0.3 3 ≅30 using I o /I SQL =1. Variational-output--μ≅ε * 1/4 ≅0.3 and V≅30 but only if the optics can handle a ten

The complex and quaternionic quantum bit from relativity of simultaneity on an interferometer.

Science.gov (United States)

Garner, Andrew J P; Müller, Markus P; Dahlsten, Oscar C O

2017-12-01

The patterns of fringes produced by an interferometer have long been important testbeds for our best contemporary theories of physics. Historically, interference has been used to contrast quantum mechanics with classical physics, but recently experiments have been performed that test quantum theory against even more exotic alternatives. A physically motivated family of theories are those where the state space of a two-level system is given by a sphere of arbitrary dimension. This includes classical bits, and real, complex and quaternionic quantum theory. In this paper, we consider relativity of simultaneity (i.e. that observers may disagree about the order of events at different locations) as applied to a two-armed interferometer, and show that this forbids most interference phenomena more complicated than those of complex quantum theory. If interference must depend on some relational property of the setting (such as path difference), then relativity of simultaneity will limit state spaces to standard complex quantum theory, or a subspace thereof. If this relational assumption is relaxed, we find one additional theory compatible with relativity of simultaneity: quaternionic quantum theory. Our results have consequences for current laboratory interference experiments: they have to be designed carefully to avoid rendering beyond-quantum effects invisible by relativity of simultaneity.

Holodeck Testbed Project

Science.gov (United States)

Arias, Adriel (Inventor)

2016-01-01

The main objective of the Holodeck Testbed is to create a cost effective, realistic, and highly immersive environment that can be used to train astronauts, carry out engineering analysis, develop procedures, and support various operations tasks. Currently, the Holodeck testbed allows to step into a simulated ISS (International Space Station) and interact with objects; as well as, perform Extra Vehicular Activities (EVA) on the surface of the Moon or Mars. The Holodeck Testbed is using the products being developed in the Hybrid Reality Lab (HRL). The HRL is combining technologies related to merging physical models with photo-realistic visuals to create a realistic and highly immersive environment. The lab also investigates technologies and concepts that are needed to allow it to be integrated with other testbeds; such as, the gravity offload capability provided by the Active Response Gravity Offload System (ARGOS). My main two duties were to develop and animate models for use in the HRL environments and work on a new way to interface with computers using Brain Computer Interface (BCI) technology. On my first task, I was able to create precise computer virtual tool models (accurate down to the thousandths or hundredths of an inch). To make these tools even more realistic, I produced animations for these tools so they would have the same mechanical features as the tools in real life. The computer models were also used to create 3D printed replicas that will be outfitted with tracking sensors. The sensor will allow the 3D printed models to align precisely with the computer models in the physical world and provide people with haptic/tactile feedback while wearing a VR (Virtual Reality) headset and interacting with the tools. Getting close to the end of my internship the lab bought a professional grade 3D Scanner. With this, I was able to replicate more intricate tools at a much more time-effective rate. The second task was to investigate the use of BCI to control

A Reconfigurable Testbed Environment for Spacecraft Autonomy

Science.gov (United States)

Biesiadecki, Jeffrey; Jain, Abhinandan

1996-01-01

A key goal of NASA's New Millennium Program is the development of technology for increased spacecraft on-board autonomy. Achievement of this objective requires the development of a new class of ground-based automony testbeds that can enable the low-cost and rapid design, test, and integration of the spacecraft autonomy software. This paper describes the development of an Autonomy Testbed Environment (ATBE) for the NMP Deep Space I comet/asteroid rendezvous mission.

M1 mirror print-through investigation and performance on the thermo-opto-mechanical testbed for the Space Interferometry Mission

Science.gov (United States)

Feria, V. Alfonso; Lam, Jonathan; Van Buren, Dave

2006-06-01

SIM PlanetQuest (SIM) is a large (9-meter baseline) space-borne optical interferometer that will determine the position and distance of stars to high accuracy. With microarcsecond measurements SIM will probe nearby stars for Earth-sized planets. To achieve this precision, SIM requires very tight manufacturing tolerances and high stability of optical components. To reduce technical risks, the SIM project developed an integrated thermal, mechanical and optical testbed (TOM3) to allow predictions of the system performance at the required high precision. The TOM3 testbed used full-scale brassboard optical components and picometer-class metrology to reach the SIM target performance levels. During the testbed integration and after one of the testbed mirrors, M1, was bonded into its mount, some surface distortion dimples that exceeded the optical specification were discovered. A detailed finite element model was used to analyze different load cases to try to determine the source of the M1 surface deformations. The same model was also used to compare with actual deformations due to varied thermal conditions on the TOM3 testbed. This paper presents the studies carried out to determine the source of the surface distortions on the M1 mirror as well as comparison and model validation during testing. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Correction of detector nonlinearity for the balloonborne Michelson Interferometer for Passive Atmospheric Sounding.

Science.gov (United States)

Kleinert, Anne

2006-01-20

The detectors used in the cryogenic limb-emission sounder MIPAS-B2 (Michelson Interferometer for Passive Atmospheric Sounding) show a nonlinear response, which leads to radiometric errors in the calibrated spectra if the nonlinearity is not taken into account. In the case of emission measurements, the dominant error that arises from the nonlinearity is the changing detector responsivity as the incident photon load changes. The effect of the distortion of a single interferogram can be neglected. A method to characterize the variable responsivity and to correct for this effect is proposed. Furthermore, a detailed error estimation is presented.

AMS San Diego Testbed - Calibration Data

Data.gov (United States)

Department of Transportation — The data in this repository were collected from the San Diego, California testbed, namely, I-15 from the interchange with SR-78 in the north to the interchange with...

Slow-Light-Enhanced Spectral Interferometers, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We proposoe a research program aimed at developing spectral interferometers with dramatically enhanced performance. A key aspect of our approach is to place a highly...

Turbulence-Free Double-slit Interferometer

Science.gov (United States)

Smith, Thomas A.; Shih, Yanhua

2018-02-01

Optical turbulence can be detrimental for optical observations. For instance, atmospheric turbulence may reduce the visibility or completely blur out the interference produced by an interferometer in open air. However, a simple two-photon interference theory based on Einstein's granularity picture of light makes a turbulence-free interferometer possible; i.e., any refraction index, length, or phase variations along the optical paths of the interferometer do not have any effect on its interference. Applying this mechanism, the reported experiment demonstrates a two-photon double-slit interference that is insensitive to atmospheric turbulence. The turbulence-free mechanism and especially the turbulence-free interferometer would be helpful in optical observations that require high sensitivity and stability such as for gravitational-wave detection.

NOAA JPSS Advanced Technology Microwave Sounder (ATMS) Remapped to Cross-track Infrared Sounder (CrIS) Sensor Data Record (SDR) from IDPS

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Technology Microwave Sounder (ATMS) is a 22 channel microwave sounder on board the Suomi NPP satellite that provides continuous cross-track scanning in...

The EUMETSAT Polar System - Second Generation (EPS-SG) micro-wave imaging (MWI) mission

Science.gov (United States)

Bojkov, B. R.; Accadia, C.; Klaes, D.; Canestri, A.; Cohen, M.

2017-12-01

The EUMETSAT Polar System (EPS) will be followed by a second generation system called EPS-SG. This new family of missions will contribute to the Joint Polar System being jointly set up with NOAA in the timeframe 2020-2040. These satellites will fly, like Metop (EPS), in a sun synchronous, low earth orbit at 830 km altitude and 09:30 local time descending node, providing observations over the full globe with revisit times of 12 hours. EPS-SG consists of two different satellites configurations, the EPS-SGa series dedicated to IR and MW sounding, and the EPS-SGb series dedicated to microwave imaging and scatterometry. The EPS-SG family will consist of three successive launches of each satellite-type. The Microwave Imager (MWI) will be hosted on Metop-SGb series of satellites, with the primary objective of supporting Numerical Weather Prediction (NWP) at regional and global scales. Other applications will be observation of surface parameters such as sea ice concentration and hydrology applications. The 18 MWI instrument frequencies range from 18.7 GHz to 183 GHz. All MWI channels up to 89 GHz will measure V- and H polarizations. The MWI was also designed to provide continuity of measurements for select heritage microwave imager channels (e.g. SSM/I, AMSR-E). The additional sounding channels such as the 50-55 and 118 GHz bands will provide additional cloud and precipitation information over sea and land. This combination of channels was successfully tested on the NPOESS Aircraft Sounder Testbed - Microwave Sounder (NAST-M) airborne radiometer, and it is the first time that will be implemented in a conical scanning configuration in a single instrument. An overview of the EPS-SG programme and the MWI instrument will be presented.

SSERVI Analog Regolith Simulant Testbed Facility

Science.gov (United States)

Minafra, J.; Schmidt, G. K.

2016-12-01

SSERVI's goals include supporting planetary researchers within NASA, other government agencies; private sector and hardware developers; competitors in focused prize design competitions; and academic sector researchers. The SSERVI Analog Regolith Simulant Testbed provides opportunities for research scientists and engineers to study the effects of regolith analog testbed research in the planetary exploration field. This capability is essential to help to understand the basic effects of continued long-term exposure to a simulated analog test environment. The current facility houses approximately eight tons of JSC-1A lunar regolith simulant in a test bin consisting of a 4 meter by 4 meter area. SSERVI provides a bridge between several groups, joining together researchers from: 1) scientific and exploration communities, 2) multiple disciplines across a wide range of planetary sciences, and 3) domestic and international communities and partnerships. This testbed provides a means of consolidating the tasks of acquisition, storage and safety mitigation in handling large quantities of regolith simulant Facility hardware and environment testing scenarios include, but are not limited to the following; Lunar surface mobility, Dust exposure and mitigation, Regolith handling and excavation, Solar-like illumination, Lunar surface compaction profile, Lofted dust, Mechanical properties of lunar regolith, and Surface features (i.e. grades and rocks) Numerous benefits vary from easy access to a controlled analog regolith simulant testbed, and planetary exploration activities at NASA Research Park, to academia and expanded commercial opportunities in California's Silicon Valley, as well as public outreach and education opportunities.

Michelson-type Radio Interferometer for University Education

Science.gov (United States)

Koda, Jin; Barrett, J. W.; Hasegawa, T.; Hayashi, M.; Shafto, G.; Slechta, J.

2013-01-01

Despite the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the futue generation of astronomers. Students need hands-on experiments to fully understand the basic concepts of interferometry. Professional interferometers are often too complicated for education, and it is difficult to guarantee access for classes in a university course. We have built a simple and affordable radio interferometer for education and used it for an undergraduate and graduate laboratory project. This interferometer's design is based on the Michelson & Peace's stellar optical interferometer, but operates at a radio wavelength using a commercial broadcast satellite dish and receiver. Two side mirrors are surfaced with kitchen aluminum foil and slide on a ladder, providing baseline coverage. This interferometer can resolve and measure the diameter of the Sun, a nice daytime experiment which can be carried out even under a marginal weather (i.e., partial cloud coverage). Commercial broadcast satellites provide convenient point sources. By comparing the Sun and satellites, students can learn how an interferometer works and resolves structures in the sky.

The Segmented Aperture Interferometric Nulling Testbed (SAINT) I: overview and air-side system description

Science.gov (United States)

Hicks, Brian A.; Lyon, Richard G.; Petrone, Peter; Ballard, Marlin; Bolcar, Matthew R.; Bolognese, Jeff; Clampin, Mark; Dogoda, Peter; Dworzanski, Daniel; Helmbrecht, Michael A.; Koca, Corina; Shiri, Ron

2016-07-01

This work presents an overview of the Segmented Aperture Interferometric Nulling Testbed (SAINT), a project that will pair an actively-controlled macro-scale segmented mirror with the Visible Nulling Coronagraph (VNC). SAINT will incorporate the VNC's demonstrated wavefront sensing and control system to refine and quantify end-to-end high-contrast starlight suppression performance. This pathfinder testbed will be used as a tool to study and refine approaches to mitigating instabilities and complex diffraction expected from future large segmented aperture telescopes.

MTG infrared sounder detection chain: first radiometric test results

Science.gov (United States)

Dumestier, D.; Pistone, F.; Dartois, T.; Blazquez, E.

2017-11-01

Europe's next fleet of geostationary meteorological satellites, MeteoSat Third Generation, will introduce new functions in addition to continuity of high-resolution meteorological data. The atmosphere Infrared Sounder (IRS), as high -end instrument, is part of this challenging program. IRS principle is a Fourier Transform Interferometer, which allows recomposing atmospheric spectrum after infrared photons detection. Transmission spectrums will be used to support numerical weather prediction. IRS instrument is able to offer full disk coverage in one hour, an on-ground resolution of 4 by 4 km, in two spectral bands (MWIR: 1600 to 2175cm-1 and LWIR: 700 to 1210cm-1) with a spectral resolution of 0.6cm-1. Among critical technologies and processes, IRS detection chain shall offer outstanding characteristics in terms of radiometric performance like Signal to Noise Ratio (SNR), dynamic range and linearity. Selected detectors are HgCdTe two-dimensions arrays, cooled at 55 Kelvins, hybridized on snapshot silicon read-out circuit at 160x160 format. Video electronics present 16 bits resolution, and the whole detection chain (Detectors and electronics) permits to reach SNR between 2 000 and 10 000 as requested by the application. Radiometric onground test results performed on design representative detection chains are presented and are confirming the challenging phase A design choices.

The DataTAG transatlantic testbed

CERN Document Server

Martin, O; Martin-Flatin, J P; Moroni, P; Nae, D; Newman, H; Ravot, S

2005-01-01

Wide area network testbeds allow researchers and engineers to test out new equipment, protocols and services in real-life situations, without jeopardizing the stability and reliability of production networks. The Data TransAtlantic Grid (DataTAG) testbed, deployed in 2002 between CERN, Geneva, Switzerland and StarLight, Chicago, IL, USA, is probably the largest testbed built to date. Jointly managed by CERN and Caltech, it is funded by the European Commission, the U.S. Department of Energy and the U.S. National Science Foundation. The main objectives of this testbed are to improve the Grid community's understanding of the networking issues posed by data- intensive Grid applications over transoceanic gigabit networks, design and develop new Grid middleware services, and improve the interoperability of European and U.S. Grid applications in High- Energy and Nuclear Physics. In this paper, we give an overview of this testbed, describe its various topologies over time, and summarize the main lessons learned after...

A Testbed For Validating the LHC Controls System Core Before Deployment

CERN Document Server

Nguyen Xuan, J

2011-01-01

Since the start-up of the LHC, it is crucial to carefully test core controls components before deploying them operationally. The Testbed of the CERN accelerator controls group was developed for this purpose. It contains different hardware (PPC, i386) running various operating systems (Linux and LynxOS) and core software components running on front-ends, communication middleware and client libraries. The Testbed first executes integration tests to verify that the components delivered by individual teams interoperate, and then system tests, which verify high-level, end-user functionality. It also verifies that different versions of components are compatible, which is vital, because not all parts of the operational LHC control system can be upgraded simultaneously. In addition, the Testbed can be used for performance and stress tests. Internally, the Testbed is driven by Atlassian Bamboo, a Continuous Integration server, which builds and deploys automatically new software versions into the Test...

Cognitive Medical Wireless Testbed System (COMWITS)

Science.gov (United States)

2016-11-01

Number: ...... ...... Sub Contractors (DD882) Names of other research staff Inventions (DD882) Scientific Progress This testbed merges two ARO grants...bit 64 bit CPU Intel Xeon Processor E5-1650v3 (6C, 3.5 GHz, Turbo, HT , 15M, 140W) Intel Core i7-3770 (3.4 GHz Quad Core, 77W) Dual Intel Xeon

Perfect crystal interferometer and its applications

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Yuji [Atominstitut der Oesterreichischen Universitaeten, Vienna (Austria)

1996-08-01

The interferometry with angstrom scale wavelength has developed steadily, and various types of interferometers have been investigated. Among them, LLL interferometers are widely used. The first neutron interferometry was achieved in 1962 by Maier-Leibnitz et al. A new type of neutron interferometers was constructed with a perfect crystal, and experimentally performed in 1974 by Rauch et al. The precise measurements with LLL neutron interferometers were performed on scattering length, gravitational effect, coherence, Fizeau effects, spin superposition, complementarity, and post-selection effects. Since the early stage of quantum physics, the double-slit experiment has served as the example of the epistemologically strange features of quantum phenomena, and its course of study is described. The time-delayed interferometry with nuclear resonant scattering of synchrotron radiation and phase transfer in time-delayed interferometry with nuclear resonant scattering were experimented, and are briefly reported. A geometric phase factor was derived for a split beam experiment as an example of cyclic evolution. The geometric phase was observed with a two-loop neutron interferometer. All the experimental results showed complete agreement with the theoretical treatment. (K.I.)

A stellar interferometer on the Moon

Science.gov (United States)

Porro, Irene

The work I present in this document has been divided into two main parts, the first one related to the IOTA project and the second one related to the study on the lunar interferometer, and an introduction section. Each section can be read independently from the other, however they are presented following the logical order in which the research work has been developed. As a guide for the reader here I describe the content of each chapter, which represents the original contribution (except when it is specifically declared) to the research accomplished. This section consists in the Introduction itself, with a presentation of the motivations for this research work, and in the chapter Interferometry from the Earth and from the Moon. The first part of this chapter shows the performances which are expected to be reached by ground-based interferometers (Colavita, 1992) by using adaptive optics systems (Beckers, 1993). The evaluation is made separately for the case of high resolution imaging and for high accuracy astrometric measurements. The most optimistic results expected for ground-based instruments determine the level of the performance that has to be required from a space interferometer (both an orbiting and a lunar instrument). In the second part of the chapter I specifically deal with the case of a lunar interferometer, which allows to put together the advantages o ered by a ground-based instrument (very long baseline, a stable platform) and those offered by the space environment (absence of atmospheric turbulence, long integration times, and wavelength range of observation from the ultraviolet to the far infrared). In order to evaluate the limits of the lunar interferometer, I need to consider three subjects with which I did not explicitly dealt for the study on IOTA: the maximum length of the baseline (Tango and Twiss, 1974), the maximum integration time, and the performances obtainable at the minimum temperature of operation (Ridgway, 1990). The chapter ends with

Graphical interface between the CIRSSE testbed and CimStation software with MCS/CTOS

Science.gov (United States)

Hron, Anna B.

1992-01-01

This research is concerned with developing a graphical simulation of the testbed at the Center for Intelligent Robotic Systems for Space Exploration (CIRSSE) and the interface which allows for communication between the two. Such an interface is useful in telerobotic operations, and as a functional interaction tool for testbed users. Creating a simulated model of a real world system, generates inevitable calibration discrepancies between them. This thesis gives a brief overview of the work done to date in the area of workcell representation and communication, describes the development of the CIRSSE interface, and gives a direction for future work in the area of system calibration. The CimStation software used for development of this interface, is a highly versatile robotic workcell simulation package which has been programmed for this application with a scale graphical model of the testbed, and supporting interface menu code. A need for this tool has been identified for the reasons of path previewing, as a window on teleoperation and for calibration of simulated vs. real world models. The interface allows information (i.e., joint angles) generated by CimStation to be sent as motion goal positions to the testbed robots. An option of the interface has been established such that joint angle information generated by supporting testbed algorithms (i.e., TG, collision avoidance) can be piped through CimStation as a visual preview of the path.

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-03-01

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

Fast Physics Testbed for the FASTER Project

Energy Technology Data Exchange (ETDEWEB)

Lin, W.; Liu, Y.; Hogan, R.; Neggers, R.; Jensen, M.; Fridlind, A.; Lin, Y.; Wolf, A.

2010-03-15

This poster describes the Fast Physics Testbed for the new FAst-physics System Testbed and Research (FASTER) project. The overall objective is to provide a convenient and comprehensive platform for fast turn-around model evaluation against ARM observations and to facilitate development of parameterizations for cloud-related fast processes represented in global climate models. The testbed features three major components: a single column model (SCM) testbed, an NWP-Testbed, and high-resolution modeling (HRM). The web-based SCM-Testbed features multiple SCMs from major climate modeling centers and aims to maximize the potential of SCM approach to enhance and accelerate the evaluation and improvement of fast physics parameterizations through continuous evaluation of existing and evolving models against historical as well as new/improved ARM and other complementary measurements. The NWP-Testbed aims to capitalize on the large pool of operational numerical weather prediction products. Continuous evaluations of NWP forecasts against observations at ARM sites are carried out to systematically identify the biases and skills of physical parameterizations under all weather conditions. The highresolution modeling (HRM) activities aim to simulate the fast processes at high resolution to aid in the understanding of the fast processes and their parameterizations. A four-tier HRM framework is established to augment the SCM- and NWP-Testbeds towards eventual improvement of the parameterizations.

SSERVI Analog Regolith Simulant Testbed Facility

Science.gov (United States)

Minafra, Joseph; Schmidt, Gregory; Bailey, Brad; Gibbs, Kristina

2016-10-01

The Solar System Exploration Research Virtual Institute (SSERVI) at NASA's Ames Research Center in California's Silicon Valley was founded in 2013 to act as a virtual institute that provides interdisciplinary research centered on the goals of its supporting directorates: NASA Science Mission Directorate (SMD) and the Human Exploration & Operations Mission Directorate (HEOMD).Primary research goals of the Institute revolve around the integration of science and exploration to gain knowledge required for the future of human space exploration beyond low Earth orbit. SSERVI intends to leverage existing JSC1A regolith simulant resources into the creation of a regolith simulant testbed facility. The purpose of this testbed concept is to provide the planetary exploration community with a readily available capability to test hardware and conduct research in a large simulant environment.SSERVI's goals include supporting planetary researchers within NASA, other government agencies; private sector and hardware developers; competitors in focused prize design competitions; and academic sector researchers.SSERVI provides opportunities for research scientists and engineers to study the effects of regolith analog testbed research in the planetary exploration field. This capability is essential to help to understand the basic effects of continued long-term exposure to a simulated analog test environment.The current facility houses approximately eight tons of JSC-1A lunar regolith simulant in a test bin consisting of a 4 meter by 4 meter area, including dust mitigation and safety oversight.Facility hardware and environment testing scenarios could include, Lunar surface mobility, Dust exposure and mitigation, Regolith handling and excavation, Solar-like illumination, Lunar surface compaction profile, Lofted dust, Mechanical properties of lunar regolith, Surface features (i.e. grades and rocks)Numerous benefits vary from easy access to a controlled analog regolith simulant testbed, and

Optical testbed for the LISA phasemeter

Science.gov (United States)

Schwarze, T. S.; Fernández Barranco, G.; Penkert, D.; Gerberding, O.; Heinzel, G.; Danzmann, K.

2016-05-01

The planned spaceborne gravitational wave detector LISA will allow the detection of gravitational waves at frequencies between 0.1 mHz and 1 Hz. A breadboard model for the metrology system aka the phasemeter was developed in the scope of an ESA technology development project by a collaboration between the Albert Einstein Institute, the Technical University of Denmark and the Danish industry partner Axcon Aps. It in particular provides the electronic readout of the main interferometer phases besides auxiliary functions. These include clock noise transfer, ADC pilot tone correction, inter-satellite ranging and data transfer. Besides in LISA, the phasemeter can also be applied in future satellite geodesy missions. Here we show the planning and advances in the implementation of an optical testbed for the full metrology chain. It is based on an ultra-stable hexagonal optical bench. This bench allows the generation of three unequal heterodyne beatnotes with a zero phase combination, thus providing the possibility to probe the phase readout for non-linearities in an optical three signal test. Additionally, the utilization of three independent phasemeters will allow the testing of the auxiliary functions. Once working, components can individually be replaced with flight-qualified hardware in this setup.

Optical testbed for the LISA phasemeter

International Nuclear Information System (INIS)

Schwarze, T S; Fernández Barranco, G; Penkert, D; Gerberding, O; Heinzel, G; Danzmann, K

2016-01-01

The planned spaceborne gravitational wave detector LISA will allow the detection of gravitational waves at frequencies between 0.1 mHz and 1 Hz. A breadboard model for the metrology system aka the phasemeter was developed in the scope of an ESA technology development project by a collaboration between the Albert Einstein Institute, the Technical University of Denmark and the Danish industry partner Axcon Aps. It in particular provides the electronic readout of the main interferometer phases besides auxiliary functions. These include clock noise transfer, ADC pilot tone correction, inter-satellite ranging and data transfer. Besides in LISA, the phasemeter can also be applied in future satellite geodesy missions. Here we show the planning and advances in the implementation of an optical testbed for the full metrology chain. It is based on an ultra-stable hexagonal optical bench. This bench allows the generation of three unequal heterodyne beatnotes with a zero phase combination, thus providing the possibility to probe the phase readout for non-linearities in an optical three signal test. Additionally, the utilization of three independent phasemeters will allow the testing of the auxiliary functions. Once working, components can individually be replaced with flight-qualified hardware in this setup. (paper)

Investigation of Planets and Small Bodies Using Decameter Wavelength Radar Sounders

Science.gov (United States)

Safaeinili, A.

2003-12-01

Decameter wavelength radar sounders provide a unique capability for the exploration of subsurface of planets and internal structure of small bodies. Recently, a number of experimental radar sounding instruments have been proposed and/or are planned to become operational in the near future. The first of these radar sounders is MARSIS (Picardi et al.) that is about to arrive at Mars on ESA's Mars Express for a two-year mission. The second radar sounder, termed SHARAD (Seu et. al), will fly on NASA's Mars Reconnaissance orbiter in 2005. MARSIS and SHARAD have complementary science objectives in that MARSIS (0.1-5.5 MHz) is designed to explore the deep subsurface with a depth resolution of ˜100 m while SHARAD (15-25 MHz) focuses its investigation to near-surface (generation of radar sounders will benefit from high power and high data rate capability that is made available through the use of Nuclear Electric generators. An example of such high-capability mission is the Jovian Icy Moons Orbiter (JIMO) where, for example, the radar sounder can be used to explore beneath the icy surfaces of Europa in search of the ice/ocean interface. The decameter wave radar sounder is probably the only instrument that has the potential of providing an accurate estimate for the ocean depth. Another exciting and rewarding area of application for planetary radar sounding is the investigation of the deep interior of small bodies (asteroids and comets). The small size of asteroids and comets provides the opportunity to collect data in a manner that enables Radio Reflection Tomographic (RRT) reconstruction of the body in the same manner that a medical ultrasound probe can image the interior of our body. This paper provides an overview of current technical capabilities and challenges and the potential of radio sounders in the investigation of planets and small bodies.

Detectability of periodic gravitational waves by initial interferometers

International Nuclear Information System (INIS)

Owen, Benjamin J

2006-01-01

I review three recent theoretical developments in neutron star physics predicting that rotating neutron stars could be very strong emitters of periodic gravitational waves. These imply a small but nonzero chance that ground-based interferometers could detect their first periodic signal in the next few years rather than after advanced upgrades. They also imply that upper limits will become astrophysically interesting before advanced upgrades. I discuss the implications for near-future searches and for the astrophysical payoffs of proposed small upgrades to initial interferometers

A Business-to-Business Interoperability Testbed: An Overview

Energy Technology Data Exchange (ETDEWEB)

Kulvatunyou, Boonserm [ORNL; Ivezic, Nenad [ORNL; Monica, Martin [Sun Microsystems, Inc.; Jones, Albert [National Institute of Standards and Technology (NIST)

2003-10-01

In this paper, we describe a business-to-business (B2B) testbed co-sponsored by the Open Applications Group, Inc. (OAGI) and the National Institute of Standard and Technology (NIST) to advance enterprise e-commerce standards. We describe the business and technical objectives and initial activities within the B2B Testbed. We summarize our initial lessons learned to form the requirements that drive the next generation testbed development. We also give an overview of a promising testing framework architecture in which to drive the testbed developments. We outline the future plans for the testbed development.

Operation Duties on the F-15B Research Testbed

Science.gov (United States)

Truong, Samson S.

2010-01-01

This presentation entails what I have done this past summer for my Co-op tour in the Operations Engineering Branch. Activities included supporting the F-15B Research Testbed, supporting the incoming F-15D models, design work, and other operations engineering duties.

Observations of Young Stellar Objects with Infrared Interferometry: Recent Results from PTI, KI and IOTA

Science.gov (United States)

Akeson, Rachel

Young stellar objects have been one of the favorite targets of infrared interferometers for many years. In this contribution I will briefly review some of the first results and their contributions to the field and then describe some of the recent results from the Keck Interferometer (KI), the Palomar Testbed Interferometer (PTI) and the Infrared-Optical Telescope Array (IOTA). This conference also saw many exciting new results from the VLTI at both near and mid-infrared wavelengths that are covered by other contributions.

Premier's imaging IR limb sounder

Science.gov (United States)

Kraft, Stefan; Bézy, Jean-Loup; Meynart, Roland; Langen, Jörg; Carnicero Dominguez, Bernardo; Bensi, Paolo; Silvestrin, Pierluigi

2017-11-01

The Imaging IR Limb Sounder (IRLS) is one of the two instruments planned on board of the candidate Earth Explorer Core Mission PREMIER. PREMIER stands for PRocess Exploration through Measurements of Infrared and Millimetre-wave Emitted Radiation. PREMIER went recently through the process of a feasibility study (Phase A) within the Earth Observation Envelope Program. Emerging from recent advanced instrument technologies IRLS shall, next to a millimetre-wave limb sounder (called STEAMR), explore the benefits of three-dimensional limb sounding with embedded cloud imaging capability. Such 3D imaging technology is expected to open a new era of limb sounding that will allow detailed studies of the link between atmospheric composition and climate, since it will map simultaneously fields of temperature and many trace gases in the mid/upper troposphere and stratosphere across a large vertical and horizontal field of view and with high vertical and horizontal resolution. PREMIER shall fly in a tandem formation looking backwards to METOP's swath and thereby improve meteorological and environmental analyses.

HIRS-AMTS satellite sounding system test - Theoretical and empirical vertical resolving power. [High resolution Infrared Radiation Sounder - Advanced Moisture and Temperature Sounder

Science.gov (United States)

Thompson, O. E.

1982-01-01

The present investigation is concerned with the vertical resolving power of satellite-borne temperature sounding instruments. Information is presented on the capabilities of the High Resolution Infrared Radiation Sounder (HIRS) and a proposed sounding instrument called the Advanced Moisture and Temperature Sounder (AMTS). Two quite different methods for assessing the vertical resolving power of satellite sounders are discussed. The first is the theoretical method of Conrath (1972) which was patterned after the work of Backus and Gilbert (1968) The Backus-Gilbert-Conrath (BGC) approach includes a formalism for deriving a retrieval algorithm for optimizing the vertical resolving power. However, a retrieval algorithm constructed in the BGC optimal fashion is not necessarily optimal as far as actual temperature retrievals are concerned. Thus, an independent criterion for vertical resolving power is discussed. The criterion is based on actual retrievals of signal structure in the temperature field.

3D Reconfigurable NoC Multiprocessor Portable Sounder for Plasmaspheric Studies

Science.gov (United States)

Dekoulis, George

2016-07-01

The paper describes the development of a prototype imaging sounder for studying the irregularities of the ionospheric plasma. Cutting edge three-dimensional reconfigurable logic has been implemented allowing highly-intensive scientific calculations to be performed in hardware. The new parallel processing algorithms implemented offer a significant amount of performance improvement in the range of 80% compared to existing digital sounder implementations. The current system configuration is taking into consideration the modern scientific needs for portability during scientific campaigns. The prototype acts as a digital signal processing experimentation platform for future larger-scale digital sounder instrumentations for measuring complex planetary plasmaspheric environments.

INFN Tier-1 Testbed Facility

International Nuclear Information System (INIS)

Gregori, Daniele; Cavalli, Alessandro; Dell'Agnello, Luca; Dal Pra, Stefano; Prosperini, Andrea; Ricci, Pierpaolo; Ronchieri, Elisabetta; Sapunenko, Vladimir

2012-01-01

INFN-CNAF, located in Bologna, is the Information Technology Center of National Institute of Nuclear Physics (INFN). In the framework of the Worldwide LHC Computing Grid, INFN-CNAF is one of the eleven worldwide Tier-1 centers to store and reprocessing Large Hadron Collider (LHC) data. The Italian Tier-1 provides the resources of storage (i.e., disk space for short term needs and tapes for long term needs) and computing power that are needed for data processing and analysis to the LHC scientific community. Furthermore, INFN Tier-1 houses computing resources for other particle physics experiments, like CDF at Fermilab, SuperB at Frascati, as well as for astro particle and spatial physics experiments. The computing center is a very complex infrastructure, the hardaware layer include the network, storage and farming area, while the software layer includes open source and proprietary software. Software updating and new hardware adding can unexpectedly deteriorate the production activity of the center: therefore a testbed facility has been set up in order to reproduce and certify the various layers of the Tier-1. In this article we describe the testbed and the checks performed.

77 FR 18793 - Spectrum Sharing Innovation Test-Bed Pilot Program

Science.gov (United States)

2012-03-28

.... 120322212-2212-01] Spectrum Sharing Innovation Test-Bed Pilot Program AGENCY: National Telecommunications... Innovation Test-Bed pilot program to assess whether devices employing Dynamic Spectrum Access techniques can... Spectrum Sharing Innovation Test-Bed (Test-Bed) pilot program to examine the feasibility of increased...

Special Sensor Microwave Imager/Sounder (SSMIS) Sensor Data Record (SDR) in netCDF

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Special Sensor Microwave Imager/Sounder (SSMIS) is a series of passive microwave conically scanning imagers and sounders onboard the DMSP satellites beginning...

Special Sensor Microwave Imager/Sounder (SSMIS) Temperature Data Record (TDR) in netCDF

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Special Sensor Microwave Imager/Sounder (SSMIS) is a series of passive microwave conically scanning imagers and sounders onboard the DMSP satellites beginning...

Easy as Pi: A Network Coding Raspberry Pi Testbed

Directory of Open Access Journals (Sweden)

Chres W. Sørensen

2016-10-01

Full Text Available In the near future, upcoming communications and storage networks are expected to tolerate major difficulties produced by huge amounts of data being generated from the Internet of Things (IoT. For these types of networks, strategies and mechanisms based on network coding have appeared as an alternative to overcome these difficulties in a holistic manner, e.g., without sacrificing the benefit of a given network metric when improving another. There has been recurrent issues on: (i making large-scale deployments akin to the Internet of Things; (ii assessing and (iii replicating the obtained results in preliminary studies. Therefore, finding testbeds that can deal with large-scale deployments and not lose historic data in order to evaluate these mechanisms are greatly needed and desirable from a research perspective. However, this can be hard to manage, not only due to the inherent costs of the hardware, but also due to maintenance challenges. In this paper, we present the required key steps to design, setup and maintain an inexpensive testbed using Raspberry Pi devices for communications and storage networks with network coding capabilities. This testbed can be utilized for any applications requiring results replicability.

Japanese large-scale interferometers

CERN Document Server

Kuroda, K; Miyoki, S; Ishizuka, H; Taylor, C T; Yamamoto, K; Miyakawa, O; Fujimoto, M K; Kawamura, S; Takahashi, R; Yamazaki, T; Arai, K; Tatsumi, D; Ueda, A; Fukushima, M; Sato, S; Shintomi, T; Yamamoto, A; Suzuki, T; Saitô, Y; Haruyama, T; Sato, N; Higashi, Y; Uchiyama, T; Tomaru, T; Tsubono, K; Ando, M; Takamori, A; Numata, K; Ueda, K I; Yoneda, H; Nakagawa, K; Musha, M; Mio, N; Moriwaki, S; Somiya, K; Araya, A; Kanda, N; Telada, S; Sasaki, M; Tagoshi, H; Nakamura, T; Tanaka, T; Ohara, K

2002-01-01

The objective of the TAMA 300 interferometer was to develop advanced technologies for kilometre scale interferometers and to observe gravitational wave events in nearby galaxies. It was designed as a power-recycled Fabry-Perot-Michelson interferometer and was intended as a step towards a final interferometer in Japan. The present successful status of TAMA is presented. TAMA forms a basis for LCGT (large-scale cryogenic gravitational wave telescope), a 3 km scale cryogenic interferometer to be built in the Kamioka mine in Japan, implementing cryogenic mirror techniques. The plan of LCGT is schematically described along with its associated R and D.

Virtual Factory Testbed

Data.gov (United States)

Federal Laboratory Consortium — The Virtual Factory Testbed (VFT) is comprised of three physical facilities linked by a standalone network (VFNet). The three facilities are the Smart and Wireless...

A Method to Analyze Threats and Vulnerabilities by Using a Cyber Security Test-bed of an Operating NPP

International Nuclear Information System (INIS)

Kim, Yong Sik; Son, Choul Woong; Lee, Soo Ill

2016-01-01

In order to implement cyber security controls for an Operating NPP, a security assessment should conduct in advance, and it is essential to analyze threats and vulnerabilities for a cyber security risk assessment phase. It might be impossible to perform a penetration test or scanning for a vulnerability analysis because the test may cause adverse effects on the inherent functions of ones. This is the reason why we develop and construct a cyber security test-bed instead of using real I and C systems in the operating NPP. In this paper, we propose a method to analyze threats and vulnerabilities of a specific target system by using a cyber security test-bed. The test-bed is being developed considering essential functions of the selected safety and non-safety system. This paper shows the method to analyze threats and vulnerabilities of a specific target system by using a cyber security test-bed. In order to develop the cyber security test-bed with both safety and non-safety functions, test-bed functions analysis and preliminary threats and vulnerabilities identification have been conducted. We will determine the attack scenarios and conduct the test-bed based vulnerability analysis

A Method to Analyze Threats and Vulnerabilities by Using a Cyber Security Test-bed of an Operating NPP

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Sik; Son, Choul Woong; Lee, Soo Ill [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

In order to implement cyber security controls for an Operating NPP, a security assessment should conduct in advance, and it is essential to analyze threats and vulnerabilities for a cyber security risk assessment phase. It might be impossible to perform a penetration test or scanning for a vulnerability analysis because the test may cause adverse effects on the inherent functions of ones. This is the reason why we develop and construct a cyber security test-bed instead of using real I and C systems in the operating NPP. In this paper, we propose a method to analyze threats and vulnerabilities of a specific target system by using a cyber security test-bed. The test-bed is being developed considering essential functions of the selected safety and non-safety system. This paper shows the method to analyze threats and vulnerabilities of a specific target system by using a cyber security test-bed. In order to develop the cyber security test-bed with both safety and non-safety functions, test-bed functions analysis and preliminary threats and vulnerabilities identification have been conducted. We will determine the attack scenarios and conduct the test-bed based vulnerability analysis.

Special relativity and interferometers

Science.gov (United States)

Han, D.; Kim, Y. S.

1988-01-01

A new generation of gravitational wave detectors is expected to be based on interferometers. Yurke et al. (1986) introduced a class of interferometers characterized by SU(1,1) which can in principle achieve a phase sensitivity approaching 1/N, where N is thte total number of photons entering the interferometer. It is shown here that the SU(1,1) interferometer can serve as an analog computer for Wigner's little group of the Poincare\\'| group.

Część I – ocena okoliczności i biomechaniki urazu

Directory of Open Access Journals (Sweden)

Grzegorz Teresiński

2014-10-01

Full Text Available Badania nad etiologią i zapobieganiem dystorsji kręgosłupa szyjnego pozostają od wielu lat w centrum zainteresowania badaczy związanych z przemysłem samochodowym i medycyną wypadkową, a także towarzystw ubezpieczeniowych. Etiopatogeneza zespołu dolegliwości związanych z tzw. whiplash (WAD budzi wciąż kontrowersje i jak dotychczas nie udało się w jednoznaczny sposób ustalić jego morfologicznych wykładników. Subiektywny charakter skarg powoduje bardzo duże trudności w obiektywizacji następstw urazu akceleracyjno- deceleracyjnego oraz weryfikacji zgłaszanych roszczeń. Celem pracy było przedstawienie  zależności biomechanicznych oraz okoliczności towarzyszących powstawaniu WAD wynikających z badań populacyjnych, statystyk firm ubezpieczeniowych oraz analizy zapisów rejestratorów zderzeń montowanych przez producentów samochodów. Znajomość technicznych aspektów okoliczności powstawania WAD może ułatwić medyczną ocenę tego rodzaju następstw.

Stable fiber interferometer

International Nuclear Information System (INIS)

Izmajlov, G.N.; Nikolaev, F.A.; Ozolin, V.V.; Grigor'yants, V.V.; Chamorovskij, Yu.K.

1989-01-01

The problem of construction the long-base Michelson interferometer for gravitational wave detection is discussed. Possible sources of noise and instability are considered. It is shown that evacuation of fiber interferometer, the winding of its arms on the glass ceramic bases, stabilization of radiation source frequency and seismic isolation of the base allow one to reduce its instability to the level, typical of mirror interferometer with the comparable optical base. 10 refs.; 2 figs

Development of a space-systems network testbed

Science.gov (United States)

Lala, Jaynarayan; Alger, Linda; Adams, Stuart; Burkhardt, Laura; Nagle, Gail; Murray, Nicholas

1988-01-01

This paper describes a communications network testbed which has been designed to allow the development of architectures and algorithms that meet the functional requirements of future NASA communication systems. The central hardware components of the Network Testbed are programmable circuit switching communication nodes which can be adapted by software or firmware changes to customize the testbed to particular architectures and algorithms. Fault detection, isolation, and reconfiguration has been implemented in the Network with a hybrid approach which utilizes features of both centralized and distributed techniques to provide efficient handling of faults within the Network.

Characteristics of monsoon inversions over the Arabian Sea observed by satellite sounder and reanalysis data sets

Directory of Open Access Journals (Sweden)

S. Dwivedi

2016-04-01

Full Text Available Monsoon inversion (MI over the Arabian Sea (AS is one of the important characteristics associated with the monsoon activity over Indian region during summer monsoon season. In the present study, we have used 5 years (2009–2013 of temperature and water vapour measurement data obtained from satellite sounder instrument, an Infrared Atmospheric Sounding Interferometer (IASI onboard MetOp satellite, in addition to ERA-Interim data, to study their characteristics. The lower atmospheric data over the AS have been examined first to identify the areas where MIs are predominant and occur with higher strength. Based on this information, a detailed study has been made to investigate their characteristics separately in the eastern AS (EAS and western AS (WAS to examine their contrasting features. The initiation and dissipation times of MIs, their percentage occurrence, strength, etc., has been examined using the huge database. The relation with monsoon activity (rainfall over Indian region during normal and poor monsoon years is also studied. WAS ΔT values are  ∼  2 K less than those over the EAS, ΔT being the temperature difference between 950 and 850 hPa. A much larger contrast between the WAS and EAS in ΔT is noticed in ERA-Interim data set vis-à-vis those observed by satellites. The possibility of detecting MI from another parameter, refractivity N, obtained directly from another satellite constellation of GPS Radio Occultation (RO (COSMIC, has also been examined. MI detected from IASI and Atmospheric Infrared Sounder (AIRS onboard the NOAA satellite have been compared to see how far the two data sets can be combined to study the MI characteristics. We suggest MI could also be included as one of the semipermanent features of southwest monsoon along with the presently accepted six parameters.

Comparative Sensitivities of Gravitational Wave Detectors Based on Atom Interferometers and Light Interferometers

Science.gov (United States)

Baker, John G.; Thorpe, J. I.

2012-01-01

We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe. Whether this potential advantage outweighs the additional complexity associated with including atom interferometers will require further study.

Conversion of conventional gravitational-wave interferometers into quantum nondemolition interferometers by modifying their input and/or output optics

Science.gov (United States)

Kimble, H. J.; Levin, Yuri; Matsko, Andrey B.; Thorne, Kip S.; Vyatchanin, Sergey P.

2002-01-01

The LIGO-II gravitational-wave interferometers (ca. 2006-2008) are designed to have sensitivities near the standard quantum limit (SQL) in the vicinity of 100 Hz. This paper describes and analyzes possible designs for subsequent LIGO-III interferometers that can beat the SQL. These designs are identical to a conventional broad band interferometer (without signal recycling), except for new input and/or output optics. Three designs are analyzed: (i) a squeezed-input interferometer (conceived by Unruh based on earlier work of Caves) in which squeezed vacuum with frequency-dependent (FD) squeeze angle is injected into the interferometer's dark port; (ii) a variational-output interferometer (conceived in a different form by Vyatchanin, Matsko and Zubova), in which homodyne detection with FD homodyne phase is performed on the output light; and (iii) a squeezed-variational interferometer with squeezed input and FD-homodyne output. It is shown that the FD squeezed-input light can be produced by sending ordinary squeezed light through two successive Fabry-Pérot filter cavities before injection into the interferometer, and FD-homodyne detection can be achieved by sending the output light through two filter cavities before ordinary homodyne detection. With anticipated technology (power squeeze factor e-2R=0.1 for input squeezed vacuum and net fractional loss of signal power in arm cavities and output optical train ɛ*=0.01) and using an input laser power Io in units of that required to reach the SQL (the planned LIGO-II power, ISQL), the three types of interferometer could beat the amplitude SQL at 100 Hz by the following amounts μ≡(Sh)/(SSQLh) and with the following corresponding increase V=1/μ3 in the volume of the universe that can be searched for a given noncosmological source: Squeezed input-μ~=(e-2R)~=0.3 and V~=1/0.33~=30 using Io/ISQL=1. Variational-output-μ~=ɛ1/4*~=0.3 and V~=30 but only if the optics can handle a ten times larger power: Io/ISQL~=1/(ɛ*)=10

An FPGA-Based Adaptable 200 MHz Bandwidth Channel Sounder for Wireless Communication Channel Characterisation

Directory of Open Access Journals (Sweden)

David L. Ndzi

2011-01-01

Full Text Available This paper describes the development of a fast adaptable FPGA-based wideband channel sounder with signal bandwidths of up to 200 MHz and channel sampling rates up to 5.4 kHz. The application of FPGA allows the user to vary the number of real-time channel response averages, channel sampling interval, and duration of measurement. The waveform, bandwidth, and frequency resolution of the sounder can be adapted for any channel under investigation. The design approach and technology used has led to a reduction in size and weight by more than 60%. This makes the sounder ideal for mobile time-variant wireless communication channels studies. Averaging allows processing gains of up to 30 dB to be achieved for measurement in weak signal conditions. The technique applied also improves reliability, reduces power consumption, and has shifted sounder design complexity from hardware to software. Test results show that the sounder can detect very small-scale variations in channels.

Comparison of Atom Interferometers and Light Interferometers as Space-Based Gravitational Wave Detectors

Science.gov (United States)

Baker, John G.

2012-01-01

We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe.

The design and implementation of the LLNL gigabit testbed

Energy Technology Data Exchange (ETDEWEB)

Garcia, D. [Lawrence Livermore National Labs., CA (United States)

1994-12-01

This paper will look at the design and implementation of the LLNL Gigabit testbed (LGTB), where various high speed networking products, can be tested in one environment. The paper will discuss the philosophy behind the design of and the need for the testbed, the tests that are performed in the testbed, and the tools used to implement those tests.

Double-grating interferometer with a one-to-one correspondence with a Michelson interferometer.

Science.gov (United States)

Xu, Yande; Sasaki, Osami; Suzuki, Takamasa

2003-10-01

We describe a double-grating interferometer that has a one-to-one correspondence with a Michelson interferometer. The half spatial periods of the gratings are equivalent to the wavelengths of the interferometer. The widths of the interference fringes can be changed easily. The intensity distribution of the interference pattern is independent of the wavelength of the light source used. The surface profile of an object can be measured because two interference beams can coincide precisely on the image plane of the object. The measuring range is much larger than that of a Michelson interferometer.

Self-calibrating interferometer

International Nuclear Information System (INIS)

Nussmeier, T.A.

1982-01-01

A self-calibrating interferometer is disclosed which forms therein a pair of Michelson interferometers with one beam length of each Michelson interferometer being controlled by a common phase shifter. The transfer function measured from the phase shifter to either of a pair of detectors is sinusoidal with a full cycle for each half wavelength of phase shifter travel. The phase difference between these two sinusoidal detector outputs represents the optical phase difference between a path of known distance and a path of unknown distance

LTE-Advanced/WLAN testbed

OpenAIRE

Plaisner, Denis

2017-01-01

Táto práca sa zaoberá skúmaním a vyhodnocovaním komunikácie štandardov LTE-Advance a WiFi (IEEE 802.11n/ac). Pri jednotlivých štandardoch je preskúmaný chybový parameter EVM. Pre prácu s jednotlivými štandardmi je navrhnuté univerzálne pracovisko (testbed). Toto univerzálne pracovisko slúži na nastavovanie vysielacieho a prijímacieho zariadenia a na spracovávanie prenášaných signálov a ich vyhodnocovanie. Pre túto prácu je vybrané prostredie Matlab, cez ktoré sa ovládajú použité prístroje ako...

Observations of atmospheric structure using an acoustic sounder

International Nuclear Information System (INIS)

Shaw, N.A.

1974-11-01

An acoustic sounder has been used to monitor the vertical temperature structure of the lowest 1.5 km of the atmosphere over the meteorological field site at Argonne National Laboratory since February 1972. Additional records were obtained near St. Louis, Mo., during the month of August. Sounder records obtained during cloudless days on which no major synoptic events occurred are separated into three characteristic phases. The first phase is the rise of the morning inversion associated with increasing solar heating of the surface after dawn. The second phase is the period of strong convective activity that usually exists between about 1100 and 1600 local time in summer and which typically destroys the inversion. The third phase includes the gradual regeneration of the low level inversion through radiation cooling of the lowest levels, followed by a period of persistence throughout the night until the first phase begins again after sunrise. Analysis of records obtained from a single acoustic sounder operating in the vertically-pointing, monostatic mode is subject to the usual ambiguity regarding the relative importance of advective effects and local changes with time. To provide a spatial sampling facility, a mobile acoustic sounding system was constructed during 1972. Details of the mobile antenna acoustic baffle or cuff are given in the Appendix. (19 figures, 1 table) (U.S.)

Advanced Artificial Intelligence Technology Testbed

Science.gov (United States)

Anken, Craig S.

1993-01-01

The Advanced Artificial Intelligence Technology Testbed (AAITT) is a laboratory testbed for the design, analysis, integration, evaluation, and exercising of large-scale, complex, software systems, composed of both knowledge-based and conventional components. The AAITT assists its users in the following ways: configuring various problem-solving application suites; observing and measuring the behavior of these applications and the interactions between their constituent modules; gathering and analyzing statistics about the occurrence of key events; and flexibly and quickly altering the interaction of modules within the applications for further study.

Fidelity of quantum interferometers

International Nuclear Information System (INIS)

Bahder, Thomas B.; Lopata, Paul A.

2006-01-01

For a generic interferometer, the conditional probability density distribution p(φ|m), for the phase φ given measurement outcome m will generally have multiple peaks. Therefore, the phase sensitivity of an interferometer cannot be adequately characterized by the standard deviation, such as Δφ∼1/√(N) (the standard limit), or Δφ∼1/N (the Heisenberg limit). We propose an alternative measure of phase sensitivity--the fidelity of an interferometer--defined as the Shannon mutual information between the phase shift φ and the measurement outcomes m. As an example application of interferometer fidelity, we consider a generic optical Mach-Zehnder interferometer, used as a sensor of a classical field. For the case where there exists no a priori information on the phase shift, we find the surprising result that maximally entangled state input leads to a lower fidelity than Fock state input, for the same photon number

X-ray interferometers

International Nuclear Information System (INIS)

Franks, A.

1980-01-01

An improved type of amplitude-division x-ray interferometer is described. The wavelength at which the interferometer can operate is variable, allowing the instrument to be used to measure x-ray wavelength, and the angle of inclination is variable for sample investigation. (U.K.)

Mesoscale Phenomenon Revealed by an Acoustic Sounder

DEFF Research Database (Denmark)

Lundtang Petersen, Erik; Jensen, Niels Otto

1976-01-01

A particular phenomenon observed on an acoustic sounder record is analyzed, and is interpreted as being associated with the passing of a land breeze front. A simple physical explanation of the frontal movements is suggested. The actual existence of the land breeze is demonstrated by examination...

Exploration Systems Health Management Facilities and Testbed Workshop

Science.gov (United States)

Wilson, Scott; Waterman, Robert; McCleskey, Carey

2004-01-01

Presentation Agenda : (1) Technology Maturation Pipeline (The Plan) (2) Cryogenic testbed (and other KSC Labs) (2a) Component / Subsystem technologies (3) Advanced Technology Development Center (ATDC) (3a) System / Vehic1e technologies (4) EL V Flight Experiments (Flight Testbeds).

Microwave Atmospheric Sounder on CubeSat

Science.gov (United States)

Padmanabhan, S.; Brown, S. E.; Kangaslahti, P.; Cofield, R.; Russell, D.; Stachnik, R. A.; Su, H.; Wu, L.; Tanelli, S.; Niamsuwan, N.

2014-12-01

To accurately predict how the distribution of extreme events may change in the future we need to understand the mechanisms that influence such events in our current climate. Our current observing system is not well-suited for observing extreme events globally due to the sparse sampling and in-homogeneity of ground-based in-situ observations and the infrequent revisit time of satellite observations. Observations of weather extremes, such as extreme precipitation events, temperature extremes, tropical and extra-tropical cyclones among others, with temporal resolution on the order of minutes and spatial resolution on the order of few kms (cost passive microwave sounding and imaging sensors on CubeSats that would work in concert with traditional flagship observational systems, such as those manifested on large environmental satellites (i.e. JPSS,WSF,GCOM-W), to monitor weather extremes. A 118/183 GHz sensor would enable observations of temperature and precipitation extremes over land and ocean as well as tropical and extra-tropical cyclones. This proposed project would enable low cost, compact radiometer instrumentation at 118 and 183 GHz that would fit in a 6U Cubesat with the objective of mass-producing this design to enable a suite of small satellites to image the key geophysical parameters needed to improve prediction of extreme weather events. We take advantage of past and current technology developments at JPL viz. HAMSR (High Altitude Microwave Scanning Radiometer), Advanced Component Technology (ACT'08) to enable low-mass, low-power high frequency airborne radiometers. In this paper, we will describe the design and implementation of the 118 GHz temperature sounder and 183 GHz humidity sounder on the 6U CubeSat. In addition, a summary of radiometer calibration and retrieval techniques of temperature and humidity will be discussed. The successful demonstration of this instrument on the 6U CubeSat would pave the way for the development of a constellation which

Environment Emulation For Wsn Testbed

Directory of Open Access Journals (Sweden)

Radosław Kapłoniak

2012-01-01

Full Text Available The development of applications for wireless sensor networks is a challenging task. For this reason, several testbed platforms have been created. They simplify the manageability of nodes by offering easy ways of programming and debugging sensor nodes. These platforms, sometimes composed of dozens of sensors, provide a convenient way for carrying out research on medium access control and data exchange between nodes. In this article, we propose the extension of the WSN testbed, which could be used for evaluating and testing the functionality of sensor networks applications by emulating a real-world environment.

Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Monolithic Interferometer Design and Test

Science.gov (United States)

Harlander, John M.; Englert, Christoph R.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Zastera, Vaz; Bach, Bernhard W.; Mende, Stephen B.

2017-10-01

The design and laboratory tests of the interferometers for the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument which measures thermospheric wind and temperature for the NASA-sponsored Ionospheric Connection (ICON) Explorer mission are described. The monolithic interferometers use the Doppler Asymmetric Spatial Heterodyne (DASH) Spectroscopy technique for wind measurements and a multi-element photometer approach to measure thermospheric temperatures. The DASH technique and overall optical design of the MIGHTI instrument are described in an overview followed by details on the design, element fabrication, assembly, laboratory tests and thermal control of the interferometers that are the heart of MIGHTI.

The comparison of environmental effects on michelson and fabry-perot interferometers utilized for the displacement measurement.

Science.gov (United States)

Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

2010-01-01

The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.

Multiphoton- and simultaneous conjugate Ramsey-Borde atom interferometers

International Nuclear Information System (INIS)

Mueller, Holger; Chiow, Sheng-wey; Herrmann, Sven; Chu, Steven

2008-01-01

We report on our experiment to measure h/M, the ratio of the Planck constant to the mass of Cs atoms, and thereby the fine-structure constant. The target accuracy is 1 part per billion or better. We focus on two recent milestones: (i) The first realization of atom interferometers based on light-pulse beam splitters that transfer the momentum of up to 12 photon pairs, which increases the useful signal (matter wave phase shift) by a factor of 144 compared to the beam splitters used in the best present atom interferometers. Moreover, they lead to a cancellation of important systematic effects. (ii) The first realization of a simultaneous pair of conjugate Ramsey-Borde interferometers. In these, the relative sign of the inertial term is reversed so that it can be cancelled. Simultaneous operation means that this holds for a time-dependent inertial term (vibrations) too, which promises a substantial improvement in the signal to noise ratio

RRTM: A rapid radiative transfer model

Energy Technology Data Exchange (ETDEWEB)

Mlawer, E.J.; Taubman, S.J.; Clough, S.A. [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States)

1996-04-01

A rapid radiative transfer model (RRTM) for the calculation of longwave clear-sky fluxes and cooling rates has been developed. The model, which uses the correlated-k method, is both accurate and computationally fast. The foundation for RRTM is the line-by-line radiative transfer model (LBLRTM) from which the relevant k-distributions are obtained. LBLRTM, which has been extensively validated against spectral observations e.g., the high-resolution sounder and the Atmospheric Emitted Radiance Interferometer, is used to validate the flux and cooling rate results from RRTM. Validations of RRTM`s results have been performed for the tropical, midlatitude summer, and midlatitude winter atmospheres, as well as for the four Intercomparison of Radiation Codes in Climate Models (ICRCCM) cases from the Spectral Radiance Experiment (SPECTRE). Details of some of these validations are presented below. RRTM has the identical atmospheric input module as LBLRTM, facilitating intercomparisons with LBLRTM and application of the model at the Atmospheric Radiation Measurement Cloud and Radiation Testbed sites.

EMERGE - ESnet/MREN Regional Science Grid Experimental NGI Testbed

Energy Technology Data Exchange (ETDEWEB)

Mambretti, Joe; DeFanti, Tom; Brown, Maxine

2001-07-31

This document is the final report on the EMERGE Science Grid testbed research project from the perspective of the International Center for Advanced Internet Research (iCAIR) at Northwestern University, which was a subcontractor to this UIC project. This report is a compilation of information gathered from a variety of materials related to this project produced by multiple EMERGE participants, especially those at Electronic Visualization Lab (EVL) at the University of Illinois at Chicago (UIC), Argonne National Lab and iCAIR. The EMERGE Science Grid project was managed by Tom DeFanti, PI from EVL at UIC.

Dr. Tulga Ersal at NSF Workshop Accessible Remote Testbeds ART'15

Science.gov (United States)

Event Archives Dr. Tulga Ersal at NSF Workshop Accessible Remote Testbeds ART'15 On November 12th, Dr Workshop on Accessible Remote Testbeds (ART'15) at Georgia Tech. From the event website: The rationale behind the ART'15 workshop is that remote-access testbeds could, if done right, significantly change how

Implementation of standard testbeds for numerical relativity

Energy Technology Data Exchange (ETDEWEB)

Babiuc, M C [Department of Physics and Physical Science, Marshall University, Huntington, WV 25755 (United States); Husa, S [Friedrich Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Alic, D [Department of Physics, University of the Balearic Islands, Cra Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Hinder, I [Center for Gravitational Wave Physics, Pennsylvania State University, University Park, PA 16802 (United States); Lechner, C [Weierstrass Institute for Applied Analysis and Stochastics (WIAS), Mohrenstrasse 39, 10117 Berlin (Germany); Schnetter, E [Center for Computation and Technology, 216 Johnston Hall, Louisiana State University, Baton Rouge, LA 70803 (United States); Szilagyi, B; Dorband, N; Pollney, D; Winicour, J [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Am Muehlenberg 1, 14076 Golm (Germany); Zlochower, Y [Center for Computational Relativity and Gravitation, School of Mathematical Sciences, Rochester Institute of Technology, 78 Lomb Memorial Drive, Rochester, New York 14623 (United States)

2008-06-21

We discuss results that have been obtained from the implementation of the initial round of testbeds for numerical relativity which was proposed in the first paper of the Apples with Apples Alliance. We present benchmark results for various codes which provide templates for analyzing the testbeds and to draw conclusions about various features of the codes. This allows us to sharpen the initial test specifications, design a new test and add theoretical insight.

Seasonal and diel patterns in sedimentary flux of krill fecal pellets recorded by an echo sounder

KAUST Repository

Rø stad, Anders; Kaartvedt, Stein

2013-01-01

We used a moored upward-facing 200 kHz echo sounder to address sedimentation of fecal pellets (FPs) from dielly migrating Meganyctiphanes norvegica. The echo sounder was located on the bottom at 150 m depth in the Oslofjord, Norway, and was cabled

Design and development of cell queuing, processing, and scheduling modules for the iPOINT input-buffered ATM testbed

Science.gov (United States)

Duan, Haoran

1997-12-01

This dissertation presents the concepts, principles, performance, and implementation of input queuing and cell-scheduling modules for the Illinois Pulsar-based Optical INTerconnect (iPOINT) input-buffered Asynchronous Transfer Mode (ATM) testbed. Input queuing (IQ) ATM switches are well suited to meet the requirements of current and future ultra-broadband ATM networks. The IQ structure imposes minimum memory bandwidth requirements for cell buffering, tolerates bursty traffic, and utilizes memory efficiently for multicast traffic. The lack of efficient cell queuing and scheduling solutions has been a major barrier to build high-performance, scalable IQ-based ATM switches. This dissertation proposes a new Three-Dimensional Queue (3DQ) and a novel Matrix Unit Cell Scheduler (MUCS) to remove this barrier. 3DQ uses a linked-list architecture based on Synchronous Random Access Memory (SRAM) to combine the individual advantages of per-virtual-circuit (per-VC) queuing, priority queuing, and N-destination queuing. It avoids Head of Line (HOL) blocking and provides per-VC Quality of Service (QoS) enforcement mechanisms. Computer simulation results verify the QoS capabilities of 3DQ. For multicast traffic, 3DQ provides efficient usage of cell buffering memory by storing multicast cells only once. Further, the multicast mechanism of 3DQ prevents a congested destination port from blocking other less- loaded ports. The 3DQ principle has been prototyped in the Illinois Input Queue (iiQueue) module. Using Field Programmable Gate Array (FPGA) devices, SRAM modules, and integrated on a Printed Circuit Board (PCB), iiQueue can process incoming traffic at 800 Mb/s. Using faster circuit technology, the same design is expected to operate at the OC-48 rate (2.5 Gb/s). MUCS resolves the output contention by evaluating the weight index of each candidate and selecting the heaviest. It achieves near-optimal scheduling and has a very short response time. The algorithm originates from a

The 2003 edition of geisa: a spectroscopic database system for the second generation vertical sounders radiance simulation

Science.gov (United States)

Jacquinet-Husson, N.; Lmd Team

The GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Atmospheric Spectroscopic Information) computer accessible database system, in its former 1997 and 2001 versions, has been updated in 2003 (GEISA-03). It is developed by the ARA (Atmospheric Radiation Analysis) group at LMD (Laboratoire de Météorologie Dynamique, France) since 1974. This early effort implemented the so-called `` line-by-line and layer-by-layer '' approach for forward radiative transfer modelling action. The GEISA 2003 system comprises three databases with their associated management softwares: a database of spectroscopic parameters required to describe adequately the individual spectral lines belonging to 42 molecules (96 isotopic species) and located in a spectral range from the microwave to the limit of the visible. The featured molecules are of interest in studies of the terrestrial as well as the other planetary atmospheres, especially those of the Giant Planets. a database of absorption cross-sections of molecules such as chlorofluorocarbons which exhibit unresolvable spectra. a database of refractive indices of basic atmospheric aerosol components. Illustrations will be given of GEISA-03, data archiving method, contents, management softwares and Web access facilities at: http://ara.lmd.polytechnique.fr The performance of instruments like AIRS (Atmospheric Infrared Sounder; http://www-airs.jpl.nasa.gov) in the USA, and IASI (Infrared Atmospheric Sounding Interferometer; http://smsc.cnes.fr/IASI/index.htm) in Europe, which have a better vertical resolution and accuracy, compared to the presently existing satellite infrared vertical sounders, is directly related to the quality of the spectroscopic parameters of the optically active gases, since these are essential input in the forward models used to simulate recorded radiance spectra. For these upcoming atmospheric sounders, the so-called GEISA/IASI sub-database system has been elaborated

Standing waves in fiber-optic interferometers

NARCIS (Netherlands)

De Haan, V.; Santbergen, R.; Tijssen, M.; Zeman, M.

2011-01-01

A study is presented giving the response of three types of fiber-optic interferometers by which a standing wave through an object is investigated. The three types are a Sagnac, Mach–Zehnder and Michelson–Morley interferometer. The response of the Mach–Zehnder interferometer is similar to the Sagnac

Deep convective cloud characterizations from both broadband imager and hyperspectral infrared sounder measurements

Science.gov (United States)

Ai, Yufei; Li, Jun; Shi, Wenjing; Schmit, Timothy J.; Cao, Changyong; Li, Wanbiao

2017-02-01

Deep convective storms have contributed to airplane accidents, making them a threat to aviation safety. The most common method to identify deep convective clouds (DCCs) is using the brightness temperature difference (BTD) between the atmospheric infrared (IR) window band and the water vapor (WV) absorption band. The effectiveness of the BTD method for DCC detection is highly related to the spectral resolution and signal-to-noise ratio (SNR) of the WV band. In order to understand the sensitivity of BTD to spectral resolution and SNR for DCC detection, a BTD to noise ratio method using the difference between the WV and IR window radiances is developed to assess the uncertainty of DCC identification for different instruments. We examined the case of AirAsia Flight QZ8501. The brightness temperatures (Tbs) over DCCs from this case are simulated for BTD sensitivity studies by a fast forward radiative transfer model with an opaque cloud assumption for both broadband imager (e.g., Multifunction Transport Satellite imager, MTSAT-2 imager) and hyperspectral IR sounder (e.g., Atmospheric Infrared Sounder) instruments; we also examined the relationship between the simulated Tb and the cloud top height. Results show that despite the coarser spatial resolution, BTDs measured by a hyperspectral IR sounder are much more sensitive to high cloud tops than broadband BTDs. As demonstrated in this study, a hyperspectral IR sounder can identify DCCs with better accuracy.

COLUMBUS as Engineering Testbed for Communications and Multimedia Equipment

Science.gov (United States)

Bank, C.; Anspach von Broecker, G. O.; Kolloge, H.-G.; Richters, M.; Rauer, D.; Urban, G.; Canovai, G.; Oesterle, E.

2002-01-01

antenna tracking system employing star sensors enables usability with any other GEO data relay satellite system. In order to be prepared for the upcoming telecom standards for ground distribution of spacecraft generated data, the interface avionics allows for testing ATM-based data formatting and routing. Three testbeds accompany these studies and designs: i)a cable-and-connector testbed measures the signal characteristics for data transfer of up to 200 Mbps through the ii)an avionics &embedded software testbed prepares for data formatting, routing, and storage in CCSDS and ATM; iii)a software testbed tests newly developed S/W man-machine interfaces and simulates bandwidth limitations, on- This makes COLUMBUS a true technology testbed for a variety of engineering topics: - application of terrestrial standard data formats for broadband, near-real-time applications in space - qualification &test of off-the-shelf multimedia equipment in manned spacecraft - secure data transmission in flexible VPNs - in-orbit demonstration of advanced data transmission technology - elaboration of efficient crew and ground operations and training procedures - evaluation of personalized displays (S/W HFI) for long-duration space missions

A Novel UAV Electric Propulsion Testbed for Diagnostics and Prognostics

Science.gov (United States)

Gorospe, George E., Jr.; Kulkarni, Chetan S.

2017-01-01

This paper presents a novel hardware-in-the-loop (HIL) testbed for systems level diagnostics and prognostics of an electric propulsion system used in UAVs (unmanned aerial vehicle). Referencing the all electric, Edge 540T aircraft used in science and research by NASA Langley Flight Research Center, the HIL testbed includes an identical propulsion system, consisting of motors, speed controllers and batteries. Isolated under a controlled laboratory environment, the propulsion system has been instrumented for advanced diagnostics and prognostics. To produce flight like loading on the system a slave motor is coupled to the motor under test (MUT) and provides variable mechanical resistance, and the capability of introducing nondestructive mechanical wear-like frictional loads on the system. This testbed enables the verification of mathematical models of each component of the propulsion system, the repeatable generation of flight-like loads on the system for fault analysis, test-to-failure scenarios, and the development of advanced system level diagnostics and prognostics methods. The capabilities of the testbed are extended through the integration of a LabVIEW-based client for the Live Virtual Constructive Distributed Environment (LVCDC) Gateway which enables both the publishing of generated data for remotely located observers and prognosers and the synchronization the testbed propulsion system with vehicles in the air. The developed HIL testbed gives researchers easy access to a scientifically relevant portion of the aircraft without the overhead and dangers encountered during actual flight.

Adjustment of a two-block X-ray interferometer and absolute measurement of lattice spacing

International Nuclear Information System (INIS)

Nakayama, Kan

1994-01-01

X-ray interferometer was invented in 1965 by Bonse and Hart, and it uses the lattice surface of a silicon single crystal as a three-dimensional diffraction lattice. It divides X-ray coherently, changes direction, combines and causes interference. It made for the first time the interference effect of X-ray into the usable form in macroscopic world. As an example of the application of X-ray interferometers to basic science, there is the absolute measurement of lattice spacing. This is the method of simultaneously measuring the same displacement with an X-ray interferometer and a light wave interferometer, and doing the absolute measurement of the lattice spacing of crystals with light wavelength. Avogadro constant is the constant that becomes the foundation of chemistry, and its relation with other basic constants is shown. The principle of X-ray interferometers is explained. As the elementary technologies for the absolute measurement of lattice spacing, the adjustment of X-ray interferometers, parallel movement table and angular adjustment table, light wave interferometer and the prevention of vibration and temperature change are described. The example of the measurement is reported. In order to improve the accuracy, the improvement of the equipment and the measurement in vacuum are prepared at present. (K.I.)

Study on talbot pattern for grating interferometer

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Ju; Oh, Oh Sung; Lee, Seung Wook [Dept. of School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of); Kim, Jong Yul [Neutron Instrument Division, Korea Atomic Energy Reserch Institute, Daejeon (Korea, Republic of)

2015-04-15

One of properties which X-ray and Neutron can be applied nondestructive test is penetration into the object with interaction leads to decrease in intensity. X-ray interaction with the matter caused by electrons, Neutron caused by atoms. They share applications in nondestructive test area because of their similarities of interaction mechanism. Grating interferometer is the one of applications produces phase contrast image and dark field image. It is defined by Talbot interferometer and Talbot-Lau interferometer according to Talbot effect and Talbot-Lau effect respectively. Talbot interferometer works with coherence beam like X-ray, and Talbot-Lau has an effect with incoherence beam like Neutron. It is important to expect the interference in grating interferometer compared normal nondestructive system. In this paper, simulation works are conducted according to Talbot and Talbot-Lau interferometer in case of X-ray and Neutron. Variation of interference intensity with X-ray and Neutron based on wave theory is constructed and calculate elements consist the system. Additionally, Talbot and Talbot-Lau interferometer is simulated in different kinds of conditions.

The Orlando TDWR testbed and airborne wind shear date comparison results

Science.gov (United States)

Campbell, Steven; Berke, Anthony; Matthews, Michael

1992-01-01

The focus of this talk is on comparing terminal Doppler Weather Radar (TDWR) and airborne wind shear data in computing a microburst hazard index called the F factor. The TDWR is a ground-based system for detecting wind shear hazards to aviation in the terminal area. The Federal Aviation Administration will begin deploying TDWR units near 45 airports in late 1992. As part of this development effort, M.I.T. Lincoln Laboratory operates under F.A.A. support a TDWR testbed radar in Orlando, FL. During the past two years, a series of flight tests has been conducted with instrumented aircraft penetrating microburst events while under testbed radar surveillance. These tests were carried out with a Cessna Citation 2 aircraft operated by the University of North Dakota (UND) Center for Aerospace Sciences in 1990, and a Boeing 737 operated by NASA Langley Research Center in 1991. A large data base of approximately 60 instrumented microburst penetrations has been obtained from these flights.

Smart Antenna UKM Testbed for Digital Beamforming System

Directory of Open Access Journals (Sweden)

2009-03-01

Full Text Available A new design of smart antenna testbed developed at UKM for digital beamforming purpose is proposed. The smart antenna UKM testbed developed based on modular design employing two novel designs of L-probe fed inverted hybrid E-H (LIEH array antenna and software reconfigurable digital beamforming system (DBS. The antenna is developed based on using the novel LIEH microstrip patch element design arranged into 4×1 uniform linear array antenna. An interface board is designed to interface to the ADC board with the RF front-end receiver. The modular concept of the system provides the capability to test the antenna hardware, beamforming unit, and beamforming algorithm in an independent manner, thus allowing the smart antenna system to be developed and tested in parallel, hence reduces the design time. The DBS was developed using a high-performance TMS320C6711TM floating-point DSP board and a 4-channel RF front-end receiver developed in-house. An interface board is designed to interface to the ADC board with the RF front-end receiver. A four-element receiving array testbed at 1.88–2.22 GHz frequency is constructed, and digital beamforming on this testbed is successfully demonstrated.

Atmospheric emitted radiance interferometer (AERI): Status and the aerosol explanation for extra window region emissions

Energy Technology Data Exchange (ETDEWEB)

Revercomb, H.E.; Knuteson, R.O.; Best, F.A.; Dirkx, T.P. [Univ. of Wisconsin, Madison, WI (United States)] [and others

1996-04-01

High spectral resolution observations of downwelling emission from 3 to 19 microns have been made by the Atmospheric Emitted Radiance Interferometer (AERI) Prototype at the Southern Great Plains (SGP) Cloud and Radiative Testbed (CART) site for over two years. The spectral data set from AERI provides a basis for improving clear sky radiative transfer; determining the radiative impact of clouds, including the derivation of cloud radiative properties; defining the influences of aerosols in the window regions; and retrieving boundary layer state properties, including temperature, water vapor, and other trace gases. The data stream of radiometrically and spectrally calibrated radiances is routinely provided by Pacific Northwest Laboratory (PNL) to those science teams requesting it, and further information on the instrument and data characteristics is available in the ARM Science Team proceedings for 1993 and 1994 and in several conference publications. This paper describes the AERI status, calibration, field experiment wit a new AERI-01 and schedule, window region emissions, and future AERI plans.

Construction of an optical test-bed for eLISA

International Nuclear Information System (INIS)

Lieser, Maike; Isleif, K-S; Schuster, S; Tröbs, M; Veith, S; Heinzel, G; Danzmann, K; Fitzsimons, E; Killow, C; Perreur-Lloyd, M; Robertson, D; Ward, H

2016-01-01

In the planned eLISA mission a key part of the system is the optical bench that holds the interferometers for reading out the inter-spacecraft distance and the test mass position. We report on ongoing technology development for the eLISA optical system like the back-link between the optical benches and the science interferometer where the local beam is interfered with the received beam from the distant spacecraft. The focus will be on a setup to investigate the tilt-to-pathlength coupling in the science interferometer. To test the science interferometer in the lab a second bench providing a laser beam and a reference interferometer is needed. We present a setup with two ultra-stable low expansion glass benches and bonded optics. To suppress the tilt-to-pathlength coupling to the required level (few μm/rad) imaging optics are placed in front of the interferometer photo diodes. (paper)

Liquid-helium-cooled Michelson interferometer

Science.gov (United States)

Augason, G. C.; Young, N.

1972-01-01

Interferometer serves as a rocket-flight spectrometer for examination of the far infrared emission spectra of astronomical objects. The double beam interferometer is readily adapted to make spectral scans and for use as a detector of discrete line emissions.

Naturally stable Sagnac-Michelson nonlinear interferometer.

Science.gov (United States)

Lukens, Joseph M; Peters, Nicholas A; Pooser, Raphael C

2016-12-01

Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing-conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed together. We observe up to 99.9% interference visibility and find evidence for noise reduction based on phase-sensitive gain. Our configuration utilizes fewer components than previous demonstrations and requires no active stabilization, offering new capabilities for practical nonlinear interferometric-based sensors.

Następstwa zdrowotne pracy w narażeniu na leki cytostatyczne w grupie zawodowej pielęgniarek i pielęgniarzy = The health consequences of occupational exposure to cytostatics among nurses

Directory of Open Access Journals (Sweden)

Agnieszka Cieślicka

2016-09-01

Agnieszka Cieślicka1, Magda Gębka2, Marcin Rząca3, Katarzyna Kocka4, Agata Pietraszek3, Agnieszka Bartoszek4, Marianna Charzyńska-Gula5   1. Blok Operacyjny, Samodzielny Publiczny Szpital Kliniczny nr 4 w Lublinie 2. Oddział Chirurgii Naczyniowej, Wojewódzki Szpital Specjalistyczny im. Stefana Kardynała Wyszyńskiego w Lublinie 3. Zakład Onkologii, Katedra Onkologii i Środowiskowej Opieki Zdrowotnej, Uniwersytet Medyczny w Lublinie 4. Zakład Medycyny Rodzinnej i Pielęgniarstwa Środowiskowego, Katedra Onkologii i Środowiskowej Opieki Zdrowotnej, Uniwersytet Medyczny w Lublinie 5. Wydział Nauk Społecznych i Humanistycznych, Państwowa Wyższa Szkoła im. prof. Stanisława Tarnowskiego w Tarnobrzegu   Streszczenie Wprowadzenie. Stosowane w leczeniu przeciwnowotworowym leki cytostatyczne działają toksycznie nie tylko na komórki nowotworowe, ale także na zdrowe. Przyjęcie chemioterapii wiąże się z występowaniem u pacjentów licznych, mocno nasilonych objawów niepożądanych. Kontakt z tymi lekami ma także personel. Toksyczne cytostatyki są wchłaniane przez personel drogą wziewną, kontaktową przez skórę, co ma miejsce nie tylko podczas przygotowywania i podawania leków przez personel pielęgniarski ale także przez kontakt z wydzielinami pacjentów. Ich wpływ na zdrowie pielęgniarek i pielęgniarzy nie jest obojętny. Cel. Celem badań było zbadanie następstw zdrowotnych pracy w narażeniu na leki cytostatyczne w grupie zawodowej pielęgniarek i pielęgniarzy. Materiał i metody. Uczestnikami badania były pielęgniarki i pielęgniarze lubelskich szpitali w liczbie 97 osób, podający pacjentom i/lub przygotowujący leki cytostatyczne. Narzędzia badawczym był autorski kwestionariusz ankiety, składający się z 14 pytań. Wyniki. Personel pielęgniarski pracujący w narażeniu na leki cytostatyczne obserwował u siebie następujące objawy: nadmierne łzawienie, suchość spojówek, zaczerwienienie i swędzenie oczu (47%, podra

Wavefront control performance modeling with WFIRST shaped pupil coronagraph testbed

Science.gov (United States)

Zhou, Hanying; Nemati, Bijian; Krist, John; Cady, Eric; Kern, Brian; Poberezhskiy, Ilya

2017-09-01

NASA's WFIRST mission includes a coronagraph instrument (CGI) for direct imaging of exoplanets. Significant improvement in CGI model fidelity has been made recently, alongside a testbed high contrast demonstration in a simulated dynamic environment at JPL. We present our modeling method and results of comparisons to testbed's high order wavefront correction performance for the shaped pupil coronagraph. Agreement between model prediction and testbed result at better than a factor of 2 has been consistently achieved in raw contrast (contrast floor, chromaticity, and convergence), and with that comes good agreement in contrast sensitivity to wavefront perturbations and mask lateral shear.

Mariner 9 Michelson interferometer.

Science.gov (United States)

Hanel, R.; Schlachman, B.; Rodgers, D.; Breihan, E.; Bywaters, R.; Chapman, F.; Rhodes, M.; Vanous, D.

1972-01-01

The Michelson interferometer on Mariner 9 measures the thermal emission spectrum of Mars between 200 and 2000 per cm (between 5 and 50 microns) with a spectral resolution of 2.4 per cm in the apodized mode. A noise equivalent radiance of 0.5 x 10 to the minus 7th W/sq cm/ster/cm is deduced from data recorded in orbit around Mars. The Mariner interferometer deviates in design from the Nimbus 3 and 4 interferometers in several areas, notably, by a cesium iodide beam splitter and certain aspects of the digital information processing. Special attention has been given to the problem of external vibration. The instrument performance is demonstrated by calibration data and samples of Mars spectra.

The Michelson interferometer-how to detect invisible interference patterns

International Nuclear Information System (INIS)

Verovnik, Ivo; Likar, Andrej

2004-01-01

In a Michelson interferometer, the contrast of the interference pattern fades away due to incoherence of light when the mirrors are not in equidistant positions. We propose an experiment where the distance between the interference fringes can be determined, even when the difference in length of the interferometer arms is far beyond the coherence length of the light, i.e. when the interference pattern disappears completely for the naked eye. We used a semiconductor laser with two photodiodes as sensors, which enabled us to follow the fluctuations of the light intensity on the screen. The distance between invisible interference fringes was determined from periodic changes of the summed fluctuating signal, obtained by changing the distance between the two sensors

Optical configurations for the Virgo interferometer

International Nuclear Information System (INIS)

Hello, P.

1993-01-01

We present, in this paper, the potential optical configurations for the VIRGO interferometer, as well as for other similar antennas (LIGO...), and the implications for its sensitivity for the detection of gravitational waves (GW's). The dual recycling arrangement may particularly relax the severe optical specifications required in a power recycling interferometer. Finally, a new idea to improve the symmetry of the interferometer is presented. (author). 11 refs., 2 figs

Seasonal and diel patterns in sedimentary flux of krill fecal pellets recorded by an echo sounder

KAUST Repository

Røstad, Anders

2013-11-01

We used a moored upward-facing 200 kHz echo sounder to address sedimentation of fecal pellets (FPs) from dielly migrating Meganyctiphanes norvegica. The echo sounder was located on the bottom at 150 m depth in the Oslofjord, Norway, and was cabled to shore for continuous measurements during winter and spring. Records of sinking pellets were for the first time observed with an echo sounder. Seasonal patterns of sedimentation of krill FPs were strongly correlated with data from continuous measurement of fluorescence, which illustrate the development of the spring bloom. Sedimenting particles were first observed as fluorescence values started to increase at the end of February and continued to increase until the bloom suddenly culminated at the end of March. This collapse of the bloom was detected on the echo sounder as a pulse of slowly sinking acoustic targets over a 2 d period. Prior to this event, there was a strong diel pattern in sedimentation, which correlated, with some time lag, with the diel migration of krill foraging at night near the surface. Pellet average sinking speeds ranged between 423 m d−1 and 804 m d−1, with a strong relation to pellet target strength, which is an acoustic proxy for size. This novel approach shows that echo sounders may be a valuable tool in studies of vertical pellet flux and, thereby, carbon flux, providing temporal resolution and direct observation of the sedimentation process, which are not obtained from standard methods.

P-sounder: an airborne P-band ice sounding radar

DEFF Research Database (Denmark)

Dall, Jørgen; Skou, Niels; Kusk, Anders

2007-01-01

is to test new ice sounding techniques, e.g. polarimetry, synthetic aperture processing, and coherent clutter suppression. A system analysis involving ice scattering models confirms that it is feasible to detect the bedrock through 4 km of ice and to detect deep ice layers. The ice sounder design features...

Highly stable polarization independent Mach-Zehnder interferometer

Energy Technology Data Exchange (ETDEWEB)

Mičuda, Michal, E-mail: micuda@optics.upol.cz; Doláková, Ester; Straka, Ivo; Miková, Martina; Dušek, Miloslav; Fiurášek, Jaromír; Ježek, Miroslav, E-mail: jezek@optics.upol.cz [Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

2014-08-15

We experimentally demonstrate optical Mach-Zehnder interferometer utilizing displaced Sagnac configuration to enhance its phase stability. The interferometer with footprint of 27×40 cm offers individually accessible paths and shows phase deviation less than 0.4° during a 250 s long measurement. The phase drift, evaluated by means of Allan deviation, stays below 3° or 7 nm for 1.5 h without any active stabilization. The polarization insensitive design is verified by measuring interference visibility as a function of input polarization. For both interferometer's output ports and all tested polarization states the visibility stays above 93%. The discrepancy in visibility for horizontal and vertical polarization about 3.5% is caused mainly by undesired polarization dependence of splitting ratio of the beam splitter used. The presented interferometer device is suitable for quantum-information and other sensitive applications where active stabilization is complicated and common-mode interferometer is not an option as both the interferometer arms have to be accessible individually.

Evidence of Convective Redistribution of Carbon Monoxide in Aura Tropospheric Emission Sounder (TES) and Microwave Limb Sounder (MLS) Observations

Science.gov (United States)

Manyin, Michael; Douglass, Anne; Schoeberl, Mark

2010-01-01

Vertical convective transport is a key element of the tropospheric circulation. Convection lofts air from the boundary layer into the free troposphere, allowing surface emissions to travel much further, and altering the rate of chemical processes such as ozone production. This study uses satellite observations to focus on the convective transport of CO from the boundary layer to the mid and upper troposphere. Our hypothesis is that strong convection associated with high rain rate regions leads to a correlation between mid level and upper level CO amounts. We first test this hypothesis using the Global Modeling Initiative (GMI) chemistry and transport model. We find the correlation is robust and increases as the precipitation rate (the strength of convection) increases. We next examine three years of CO profiles from the Tropospheric Emission Sounder (TES) and Microwave Limb Sounder (MLS) instruments aboard EOS Aura. Rain rates are taken from the Tropical Rainfall Measuring Mission (TRMM) 3B-42 multi-satellite product. Again we find a correlation between mid-level and upper tropospheric CO, which increases with rain rate. Our result shows the critical importance of tropical convection in coupling vertical levels of the troposphere in the transport of trace gases. The effect is seen most clearly in strong convective regions such as the Inter-tropical Convergence Zone.

Designing, Implementing and Documenting the Atlas Networking Test-bed.

CERN Document Server

Martinsen, Hans Åge

The A Toroidal LHC ApparatuS (Atlas) experiment at the Large Hadron Colider (LHC) in European Organization for Nuclear Research (CERN), Geneva is a production environment. To develop new architectures, test new equipment and evaluate new technologies a well supported test bench is needed. A new one is now being commissioned and I will take a leading role in its development, commissioning and operation. This thesis will cover the requirements, the implementation, the documentation and the approach to the different challenges in implementing the testbed. I will be joining the project in the early stages and start by following the work that my colleagues are doing and then, as I get a better understanding, more responsibility will be given to me. To be able to suggest and implement solutions I will have to understand what the requirements are and how to achieve these requirements with the given resources.

Picometre displacement measurements using a differential Fabry-Perot optical interferometer and an x-ray interferometer

Science.gov (United States)

Çelik, Mehmet; Hamid, Ramiz; Kuetgens, Ulrich; Yacoot, Andrew

2012-08-01

X-ray interferometry is emerging as an important tool for dimensional nanometrology both for sub-nanometre measurement and displacement. It has been used to verify the performance of the next generation of displacement measuring optical interferometers within the European Metrology Research Programme project NANOTRACE. Within this project a more detailed set of comparison measurements between the x-ray interferometer and a dual channel Fabry-Perot optical interferometer (DFPI) have been made to demonstrate the capabilities of both instruments for picometre displacement metrology. The results show good agreement between the two instruments, although some minor differences of less than 5 pm have been observed.

Development Challenges of Utilizing a Corner Cube Mechanism Design with Successful IASI Flight Heritage for the Infrared Sounder (IRS) on MTG: Recurrent Mechanical Design not Correlated to Recurrent Development

Science.gov (United States)

Spanoudakis, Peter; Schwab, Philippe; Kiener, Lionel; Saudan, Herve; Perruchoud, Gerald

2015-09-01

The Corner Cube Mechanism (CCM) design for the Infra-Red Sounder (IRS) on MTG is based on the successful mechanism currently in orbit on the Infrared Atmospheric Sounding Interferometers (IASI) on the Metop satellites. The overall CCM performance is described with attention given to the specific design developments for the MTG project. A description is presented of the modifications introduced and challenges encountered to adapt the IASI space heritage design (which is only 15 years old) to meet the MTG specifications. A detailed account is provided regarding the tests performed on the adapted components for the new programme. The major issues encountered and solutions proposed are illustrated concerning the voice- coil actuator development, optical switch design, fatigue life of the flexure components and the adaptation of the launch locking device. Nevertheless, an Engineering Qualification Model was rapidly manufactured and now undergoing a qualification test campaign.

Magdalena Ridge Observatory Interferometer: Status Update

National Research Council Canada - National Science Library

Creech-Eakman, M. J; Bakker, E. J; Buscher, D. F; Coleman, T. A; Haniff, C. A; Jurgenson, C. A; Klinglesmith, III, D. A; Parameswariah, C. B; Romero, V. D; Shtromberg, A. V; Young, J. S

2006-01-01

The Magdalena Ridge Observatory Interferometer (MROI) is a ten element optical and near-infrared imaging interferometer being built in the Magdalena mountains west of Socorro, NM at an altitude of 3230 m...

Two-path plasmonic interferometer with integrated detector

Science.gov (United States)

Dyer, Gregory Conrad; Shaner, Eric A.; Aizin, Gregory

2016-03-29

An electrically tunable terahertz two-path plasmonic interferometer with an integrated detection element can down convert a terahertz field to a rectified DC signal. The integrated detector utilizes a resonant plasmonic homodyne mixing mechanism that measures the component of the plasma waves in-phase with an excitation field that functions as the local oscillator in the mixer. The plasmonic interferometer comprises two independently tuned electrical paths. The plasmonic interferometer enables a spectrometer-on-a-chip where the tuning of electrical path length plays an analogous role to that of physical path length in macroscopic Fourier transform interferometers.

Towards standard testbeds for numerical relativity

International Nuclear Information System (INIS)

Alcubierre, Miguel; Allen, Gabrielle; Bona, Carles; Fiske, David; Goodale, Tom; Guzman, F Siddhartha; Hawke, Ian; Hawley, Scott H; Husa, Sascha; Koppitz, Michael; Lechner, Christiane; Pollney, Denis; Rideout, David; Salgado, Marcelo; Schnetter, Erik; Seidel, Edward; Shinkai, Hisa-aki; Shoemaker, Deirdre; Szilagyi, Bela; Takahashi, Ryoji; Winicour, Jeff

2004-01-01

In recent years, many different numerical evolution schemes for Einstein's equations have been proposed to address stability and accuracy problems that have plagued the numerical relativity community for decades. Some of these approaches have been tested on different spacetimes, and conclusions have been drawn based on these tests. However, differences in results originate from many sources, including not only formulations of the equations, but also gauges, boundary conditions, numerical methods and so on. We propose to build up a suite of standardized testbeds for comparing approaches to the numerical evolution of Einstein's equations that are designed to both probe their strengths and weaknesses and to separate out different effects, and their causes, seen in the results. We discuss general design principles of suitable testbeds, and we present an initial round of simple tests with periodic boundary conditions. This is a pivotal first step towards building a suite of testbeds to serve the numerical relativists and researchers from related fields who wish to assess the capabilities of numerical relativity codes. We present some examples of how these tests can be quite effective in revealing various limitations of different approaches, and illustrating their differences. The tests are presently limited to vacuum spacetimes, can be run on modest computational resources and can be used with many different approaches used in the relativity community

Towards standard testbeds for numerical relativity

Energy Technology Data Exchange (ETDEWEB)

Alcubierre, Miguel [Inst. de Ciencias Nucleares, Univ. Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico); Allen, Gabrielle; Goodale, Tom; Guzman, F Siddhartha; Hawke, Ian; Husa, Sascha; Koppitz, Michael; Lechner, Christiane; Pollney, Denis; Rideout, David [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany); Bona, Carles [Departament de Fisica, Universitat de les Illes Balears, Ctra de Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Fiske, David [Dept. of Physics, Univ. of Maryland, College Park, MD 20742-4111 (United States); Hawley, Scott H [Center for Relativity, Univ. of Texas at Austin, Austin, Texas 78712 (United States); Salgado, Marcelo [Inst. de Ciencias Nucleares, Univ. Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico); Schnetter, Erik [Inst. fuer Astronomie und Astrophysik, Universitaet Tuebingen, 72076 Tuebingen (Germany); Seidel, Edward [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Inst., 14476 Golm (Germany); Shinkai, Hisa-aki [Computational Science Div., Inst. of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Shoemaker, Deirdre [Center for Radiophysics and Space Research, Cornell Univ., Ithaca, NY 14853 (United States); Szilagyi, Bela [Dept. of Physics and Astronomy, Univ. of Pittsburgh, Pittsburgh, PA 15260 (United States); Takahashi, Ryoji [Theoretical Astrophysics Center, Juliane Maries Vej 30, 2100 Copenhagen, (Denmark); Winicour, Jeff [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany)

2004-01-21

In recent years, many different numerical evolution schemes for Einstein's equations have been proposed to address stability and accuracy problems that have plagued the numerical relativity community for decades. Some of these approaches have been tested on different spacetimes, and conclusions have been drawn based on these tests. However, differences in results originate from many sources, including not only formulations of the equations, but also gauges, boundary conditions, numerical methods and so on. We propose to build up a suite of standardized testbeds for comparing approaches to the numerical evolution of Einstein's equations that are designed to both probe their strengths and weaknesses and to separate out different effects, and their causes, seen in the results. We discuss general design principles of suitable testbeds, and we present an initial round of simple tests with periodic boundary conditions. This is a pivotal first step towards building a suite of testbeds to serve the numerical relativists and researchers from related fields who wish to assess the capabilities of numerical relativity codes. We present some examples of how these tests can be quite effective in revealing various limitations of different approaches, and illustrating their differences. The tests are presently limited to vacuum spacetimes, can be run on modest computational resources and can be used with many different approaches used in the relativity community.

Picometre displacement measurements using a differential Fabry–Perot optical interferometer and an x-ray interferometer

International Nuclear Information System (INIS)

Çelik, Mehmet; Hamid, Ramiz; Kuetgens, Ulrich; Yacoot, Andrew

2012-01-01

X-ray interferometry is emerging as an important tool for dimensional nanometrology both for sub-nanometre measurement and displacement. It has been used to verify the performance of the next generation of displacement measuring optical interferometers within the European Metrology Research Programme project NANOTRACE. Within this project a more detailed set of comparison measurements between the x-ray interferometer and a dual channel Fabry–Perot optical interferometer (DFPI) have been made to demonstrate the capabilities of both instruments for picometre displacement metrology. The results show good agreement between the two instruments, although some minor differences of less than 5 pm have been observed. (paper)

Mounted Smartphones as Measurement and Control Platforms for Motor-Based Laboratory Test-Beds

Directory of Open Access Journals (Sweden)

Jared A. Frank

2016-08-01

Full Text Available Laboratory education in science and engineering often entails the use of test-beds equipped with costly peripherals for sensing, acquisition, storage, processing, and control of physical behavior. However, costly peripherals are no longer necessary to obtain precise measurements and achieve stable feedback control of test-beds. With smartphones performing diverse sensing and processing tasks, this study examines the feasibility of mounting smartphones directly to test-beds to exploit their embedded hardware and software in the measurement and control of the test-beds. This approach is a first step towards replacing laboratory-grade peripherals with more compact and affordable smartphone-based platforms, whose interactive user interfaces can engender wider participation and engagement from learners. Demonstrative cases are presented in which the sensing, computation, control, and user interaction with three motor-based test-beds are handled by a mounted smartphone. Results of experiments and simulations are used to validate the feasibility of mounted smartphones as measurement and feedback control platforms for motor-based laboratory test-beds, report the measurement precision and closed-loop performance achieved with such platforms, and address challenges in the development of platforms to maintain system stability.

Mounted Smartphones as Measurement and Control Platforms for Motor-Based Laboratory Test-Beds.

Science.gov (United States)

Frank, Jared A; Brill, Anthony; Kapila, Vikram

2016-08-20

Laboratory education in science and engineering often entails the use of test-beds equipped with costly peripherals for sensing, acquisition, storage, processing, and control of physical behavior. However, costly peripherals are no longer necessary to obtain precise measurements and achieve stable feedback control of test-beds. With smartphones performing diverse sensing and processing tasks, this study examines the feasibility of mounting smartphones directly to test-beds to exploit their embedded hardware and software in the measurement and control of the test-beds. This approach is a first step towards replacing laboratory-grade peripherals with more compact and affordable smartphone-based platforms, whose interactive user interfaces can engender wider participation and engagement from learners. Demonstrative cases are presented in which the sensing, computation, control, and user interaction with three motor-based test-beds are handled by a mounted smartphone. Results of experiments and simulations are used to validate the feasibility of mounted smartphones as measurement and feedback control platforms for motor-based laboratory test-beds, report the measurement precision and closed-loop performance achieved with such platforms, and address challenges in the development of platforms to maintain system stability.

Does an atom interferometer test the gravitational redshift at the Compton frequency?

International Nuclear Information System (INIS)

Wolf, Peter; Borde, Christian J; Blanchet, Luc; Reynaud, Serge; Salomon, Christophe; Cohen-Tannoudji, Claude

2011-01-01

Atom interferometers allow the measurement of the acceleration of freely falling atoms with respect to an experimental platform at rest on Earth's surface. Such experiments have been used to test the universality of free fall by comparing the acceleration of the atoms to that of a classical freely falling object. In a recent paper, Mueller et al (2010 Nature 463 926-9) argued that atom interferometers also provide a very accurate test of the gravitational redshift (or universality of clock rates). Considering the atom as a clock operating at the Compton frequency associated with the rest mass, they claimed that the interferometer measures the gravitational redshift between the atom-clocks in the two paths of the interferometer at different values of gravitational potentials. In this paper, we analyze this claim in the frame of general relativity and of different alternative theories. We show that the difference of 'Compton phases' between the two paths of the interferometer is actually zero in a large class of theories, including general relativity, all metric theories of gravity, most non-metric theories and most theoretical frameworks used to interpret the violations of the equivalence principle. Therefore, in most plausible theoretical frameworks, there is no redshift effect and atom interferometers only test the universality of free fall. We also show that frameworks in which atom interferometers would test the redshift pose serious problems, such as (i) violation of the Schiff conjecture, (ii) violation of the Feynman path integral formulation of quantum mechanics and of the principle of least action for matter waves, (iii) violation of energy conservation, and more generally (iv) violation of the particle-wave duality in quantum mechanics. Standard quantum mechanics is no longer valid in such frameworks, so that a consistent interpretation of the experiment would require an alternative formulation of quantum mechanics. As such an alternative has not been

High Precision Testbed to Evaluate Ethernet Performance for In-Car Networks

DEFF Research Database (Denmark)

Revsbech, Kasper; Madsen, Tatiana Kozlova; Schiøler, Henrik

2012-01-01

Validating safety-critical real-time systems such as in-car networks often involves a model-based performance analysis of the network. An important issue performing such analysis is to provide precise model parameters, matching the actual equipment. One way to obtain such parameters is to derive...... them by measurements of the equipment. In this work we describe the design of a testbed enabling active measurements on up to 1 [Gb=Sec] Copper based Ethernet Switches. By use of the testbed it self, we conduct a series of tests where the precision of the testbed is estimated. We find a maximum error...

Study of Geological Analogues for Understanding the Radar Sounder Response of the RIME Targets

Science.gov (United States)

Thakur, S.; Bruzzone, L.

2017-12-01

Radar for Icy Moon Exploration (RIME), the radar sounder onboard the Jupiter Icy Moons Explorer (JUICE), is aimed at characterizing the ice shells of the Jovian moons - Ganymede, Europa and Callisto. RIME is optimized to operate at 9 MHz central frequency with bandwidth of 1 MHz and 2.7 MHz to achieve a penetration depth up to 9 km through ice. We have developed an approach to the definition of a database of simulated RIME radargrams by leveraging the data available from airborne and orbital radar sounder acquisitions over geological analogues of the expected icy moon features. These simulated radargrams are obtained by merging real radar sounder data with models of the subsurface of the Jupiter icy moons. They will be useful for geological interpretation of the RIME radargrams and for better predicting the performance of RIME. The database will also be useful in developing pre-processing and automatic feature extraction algorithms to support data analysis during the mission phase of RIME. Prior to the JUICE mission exploring the Jovian satellites with RIME, there exist radar sounders such as SHARAD (onboard MRO) and MARSIS (onboard MEX) probing Mars, the LRS (onboard SELENE) probing the Moon, and many airborne sounders probing the polar regions of Earth. Analogues have been identified in these places based on similarity in geo-morphological expression. Moreover, other analogues have been identified on the Earth for possible dedicated acquisition campaigns before the RIME operations. By assuming that the subsurface structure of the RIME targets is approximately represented in the analogue radargrams, the difference in composition is accounted for by imposing different dielectric and subsurface attenuation models. The RIME radargrams are simulated from the analogue radargrams using the radar equation and the RIME processing chain and accounting for different possible scenarios in terms of subsurface structure, dielectric properties and instrument parameters. For

Two-wavelength HeNe laser interferometer

International Nuclear Information System (INIS)

Granneman, E.H.A.

1981-01-01

This paper presents an interferometer set-up in which two wavelengths are used simultaneously. This enables one to determine separately the phase shifts caused by changes in plasma density and by mechanical vibrations of the interferometer structure

UARS Improved Stratospheric and Mesospheric Sounder (ISAMS) Level 3AL V001

Data.gov (United States)

National Aeronautics and Space Administration — The Improved Stratospheric and Mesospheric Sounder (ISAMS) Level 3AL data product consists of daily, 4 degree increment latitude-ordered vertical profiles of...

In-fiber integrated Michelson interferometer.

Science.gov (United States)

Yuan, Libo; Yang, Jun; Liu, Zhihai; Sun, Jiaxing

2006-09-15

A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.

Development of Liquid Propulsion Systems Testbed at MSFC

Science.gov (United States)

Alexander, Reginald; Nelson, Graham

2016-01-01

As NASA, the Department of Defense and the aerospace industry in general strive to develop capabilities to explore near-Earth, Cis-lunar and deep space, the need to create more cost effective techniques of propulsion system design, manufacturing and test is imperative in the current budget constrained environment. The physics of space exploration have not changed, but the manner in which systems are developed and certified needs to change if there is going to be any hope of designing and building the high performance liquid propulsion systems necessary to deliver crew and cargo to the further reaches of space. To further the objective of developing these systems, the Marshall Space Flight Center is currently in the process of formulating a Liquid Propulsion Systems testbed, which will enable rapid integration of components to be tested and assessed for performance in integrated systems. The manifestation of this testbed is a breadboard engine configuration (BBE) with facility support for consumables and/or other components as needed. The goal of the facility is to test NASA developed elements, but can be used to test articles developed by other government agencies, industry or academia. Joint government/private partnership is likely the approach that will be required to enable efficient propulsion system development. MSFC has recently tested its own additively manufactured liquid hydrogen pump, injector, and valves in a BBE hot firing. It is rapidly building toward testing the pump and a new CH4 injector in the BBE configuration to demonstrate a 22,000 lbf, pump-fed LO2/LCH4 engine for the Mars lander or in-space transportation. The value of having this BBE testbed is that as components are developed they may be easily integrated in the testbed and tested. MSFC is striving to enhance its liquid propulsion system development capability. Rapid design, analysis, build and test will be critical to fielding the next high thrust rocket engine. With the maturity of the

Mounted Smartphones as Measurement and Control Platforms for Motor-Based Laboratory Test-Beds

OpenAIRE

Jared A. Frank; Anthony Brill; Vikram Kapila

2016-01-01

Laboratory education in science and engineering often entails the use of test-beds equipped with costly peripherals for sensing, acquisition, storage, processing, and control of physical behavior. However, costly peripherals are no longer necessary to obtain precise measurements and achieve stable feedback control of test-beds. With smartphones performing diverse sensing and processing tasks, this study examines the feasibility of mounting smartphones directly to test-beds to exploit their em...

Wireless Sensor Networks TestBed: ASNTbed

CSIR Research Space (South Africa)

Dludla, AG

2013-05-01

Full Text Available Wireless sensor networks (WSNs) have been used in different types of applications and deployed within various environments. Simulation tools are essential for studying WSNs, especially for exploring large-scale networks. However, WSN testbeds...

UARS Improved Stratospheric and Mesospheric Sounder (ISAMS) Level 3AT V001

Data.gov (United States)

National Aeronautics and Space Administration — The Improved Stratospheric and Mesospheric Sounder (ISAMS) Level 3AT data product consists of daily, 65.536 second interval time-ordered vertical profiles of...

Dispersion cancellation in a triple Laue interferometer

International Nuclear Information System (INIS)

Lemmel, Hartmut

2014-01-01

The concept of dispersion cancellation has been established in light optics to improve the resolution of interferometric measurements on dispersive media. Odd order dispersion cancellation allows to measure phase shifts without defocusing the interferometer due to wave packet displacements, while even order dispersion cancellation allows to measure time lags without losing resolution due to wave packet spreading. We report that either type of dispersion cancellation can be realized very easily in a triple Laue interferometer. Such interferometers are Mach–Zehnder interferometers based on Bragg diffraction, and are commonly used for neutrons and x-rays. Although the first x-ray interferometer was built nearly five decades ago, the feature of dispersion cancellation hasn't been recognized so far because the concept was hardly known in the neutron and x-ray community. However, it explains right away the surprising decoupling of phase shift and spatial displacement that we have discovered recently in neutron interferometry (Lemmel and Wagh 2010 Phys. Rev. A 82 033626). Furthermore, this article might inspire the light optics community to consider whether a triple Laue interferometer for laser light would be useful and feasible. We explain how dispersion cancellation works in neutron interferometry, and we describe the setup rigorously by solving the Schrödinger equation and by calculating the path integral. We point out, that the latter has to be evaluated with special care since in our setup the beam trajectory moves with respect to the crystal lattice of the interferometer. (paper)

Growth plan for an inspirational test-bed of smart textile services

NARCIS (Netherlands)

Wensveen, S.A.G.; Tomico, O.; Bhomer, ten M.; Kuusk, K.

2015-01-01

In this pictorial we visualize the growth plan for an inspirational test-bed of smart textile product service systems. The goal of the test-bed is to inspire and inform the Dutch creative industries of textile, interaction and service design to combine their strengths and share opportunities. The

Development of stable monolithic wide-field Michelson interferometers.

Science.gov (United States)

Wan, Xiaoke; Ge, Jian; Chen, Zhiping

2011-07-20

Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations. © 2011 Optical Society of America

Direction-of-Arrival Analysis of Airborne Ice Depth Sounder Data

DEFF Research Database (Denmark)

Nielsen, Ulrik; Yan, Jie-Bang; Gogineni, Sivaprasad

2017-01-01

In this paper, we analyze the direction-of arrival(DOA) of the ice-sheet data collected over Jakobshavn Glacier with the airborne Multichannel Radar Depth Sounder (MCRDS) during the 2006 field season. We extracted weak ice–bed echoes buried in signals scattered by the rough surface of the fast...

Michelson interferometer based spatial phase shift shearography.

Science.gov (United States)

Xie, Xin; Yang, Lianxiang; Xu, Nan; Chen, Xu

2013-06-10

This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. The Michelson interferometer based shearographic system has been widely utilized in industry as a practical nondestructive test tool. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact, tilting the mirror in the Michelson interferometer also generates spatial frequency shift. Based on this feature, we introduce a simple Michelson interferometer based spatial phase shift shearography. The Fourier transform (FT) method is applied to separate the spectrum on the spatial frequency domain. The phase change due to the loading can be evaluated using a properly selected windowed inverse-FT. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, spatial resolution of couple charge device camera, and filter methods are discussed in detail. The theory and the experimental results are presented.

A nanofabricated, monolithic, path-separated electron interferometer

OpenAIRE

Agarwal, Akshay; Kim, Chung-Soo; Hobbs, Richard; Dyck, Dirk van; Berggren, Karl K.

2017-01-01

Progress in nanofabrication technology has enabled the development of numerous electron optic elements for enhancing image contrast and manipulating electron wave functions. Here, we describe a modular, self-aligned, amplitude-division electron interferometer in a conventional transmission electron microscope. The interferometer consists of two 45-nm-thick silicon layers separated by 20??m. This interferometer is fabricated from a single-crystal silicon cantilever on a transmission electron m...

A Michelson interferometer for ultracold neutrons

International Nuclear Information System (INIS)

Steyerl, A.; Malik, S.S.; Steinhauser, K.A.; Berger, L.

1979-01-01

We propose a neutron Michelson Interferometer installed within a focussing 'gravity diffractometer' for ultracold neutrons. In this arrangement the expected interference pattern depends only on the well-defined vertical component of neutron wavevector. Possible applications of such an interferometer are discussed. (orig.)

Wireless Testbed Bonsai

Science.gov (United States)

2006-02-01

wireless sensor device network, and a about 200 Stargate nodes higher-tier multi-hop peer- to-peer 802.11b wireless network. Leading up to the full ExScal...deployment, we conducted spatial scaling tests on our higher-tier protocols on a 7 × 7 grid of Stargates nodes 45m and with 90m separations respectively...onW and its scaled version W̃ . III. EXPERIMENTAL SETUP Description of Kansei testbed. A stargate is a single board linux-based computer [7]. It uses a

SCDU Testbed Automated In-Situ Alignment, Data Acquisition and Analysis

Science.gov (United States)

Werne, Thomas A.; Wehmeier, Udo J.; Wu, Janet P.; An, Xin; Goullioud, Renaud; Nemati, Bijan; Shao, Michael; Shen, Tsae-Pyng J.; Wang, Xu; Weilert, Mark A.;

Total column ozone retrieval using INSAT-3D sounder in the tropics ...

Indian Academy of Sciences (India)

important for ozone estimation and lower instrument noise results in better ozone ... the Indian Space Research Organisation (ISRO) ... tivity of the sounder ozone band corresponding to .... NOAA Climate Monitoring and Diagnostics Labo-.

Integrating Simulated Physics and Device Virtualization in Control System Testbeds

OpenAIRE

Redwood , Owen; Reynolds , Jason; Burmester , Mike

2016-01-01

Part 3: INFRASTRUCTURE MODELING AND SIMULATION; International audience; Malware and forensic analyses of embedded cyber-physical systems are tedious, manual processes that testbeds are commonly not designed to support. Additionally, attesting the physics impact of embedded cyber-physical system malware has no formal methodologies and is currently an art. This chapter describes a novel testbed design methodology that integrates virtualized embedded industrial control systems and physics simula...

Design of aircraft cabin testbed for stress free air travel experiment

NARCIS (Netherlands)

Tan, C.F.; Chen, W.; Rauterberg, G.W.M.

2009-01-01

The paper presents an aircraft cabin testbed that is designed and built for the stress free air travel experiment. The project is funded by European Union in the aim of improving air travel comfort during long haul flight. The testbed is used to test and validate the adaptive system that is capable

Iodine-frequency-stabilized laser diode and displacement-measuring interferometer based on sinusoidal phase modulation

Science.gov (United States)

Duong, Quang Anh; Vu, Thanh Tung; Higuchi, Masato; Wei, Dong; Aketagawa, Masato

2018-06-01

We propose a sinusoidal phase modulation method to achieve both the frequency stabilization of an external-cavity laser diode (ECLD) to an 127I2 saturated absorption transition near 633 nm and displacement measurement using a Mach–Zehnder interferometer. First, the frequency of the ECLD is stabilized to the b 21 hyperfine component of the P(33) 6-3 transition of 127I2 by combining sinusoidal phase modulation by an electro-optic modulator and frequency modulation spectroscopy by chopping the pump beam using an acousto-optic modulator. Even though a small modulation index of m  =  3.768 rad is utilized, a relative frequency stability of 10‑11 order is obtained over a sampling time of 400 s. Secondly, the frequency-stabilized ECLD is applied as a light source to a Mach–Zehnder interferometer. From the two consecutive modulation harmonics (second and third orders) involved in the interferometer signal, the displacement of the moving mirror is determined for four optical path differences (L 0  =  100, 200, 500, and 1000 mm). The measured modulation indexes for the four optical path differences coincide with the designated value (3.768 rad) within 0.5%. Compared with the sinusoidal frequency modulation Michelson interferometer (Vu et al 2016 Meas. Sci. Technol. 27 105201) which was demonstrated by some of the same authors of this paper, the phase modulation Mach–Zhender interferometer could fix the modulation index to a constant value for the four optical path differences. In this report, we discuss the measurement principle, experimental system, and results.

Mounted Smartphones as Measurement and Control Platforms for Motor-Based Laboratory Test-Beds †

Science.gov (United States)

Frank, Jared A.; Brill, Anthony; Kapila, Vikram

2016-01-01

Laboratory education in science and engineering often entails the use of test-beds equipped with costly peripherals for sensing, acquisition, storage, processing, and control of physical behavior. However, costly peripherals are no longer necessary to obtain precise measurements and achieve stable feedback control of test-beds. With smartphones performing diverse sensing and processing tasks, this study examines the feasibility of mounting smartphones directly to test-beds to exploit their embedded hardware and software in the measurement and control of the test-beds. This approach is a first step towards replacing laboratory-grade peripherals with more compact and affordable smartphone-based platforms, whose interactive user interfaces can engender wider participation and engagement from learners. Demonstrative cases are presented in which the sensing, computation, control, and user interaction with three motor-based test-beds are handled by a mounted smartphone. Results of experiments and simulations are used to validate the feasibility of mounted smartphones as measurement and feedback control platforms for motor-based laboratory test-beds, report the measurement precision and closed-loop performance achieved with such platforms, and address challenges in the development of platforms to maintain system stability. PMID:27556464

Atom Wave Interferometers

National Research Council Canada - National Science Library

Pritchard, David

1999-01-01

Matter wave interferometers, in which de Broglie waves are coherently split and then recombined to produce interference fringes, have opened exciting new possibilities for precision and fundamental...

Data Distribution Service-Based Interoperability Framework for Smart Grid Testbed Infrastructure

Directory of Open Access Journals (Sweden)

Tarek A. Youssef

2016-03-01

Full Text Available This paper presents the design and implementation of a communication and control infrastructure for smart grid operation. The proposed infrastructure enhances the reliability of the measurements and control network. The advantages of utilizing the data-centric over message-centric communication approach are discussed in the context of smart grid applications. The data distribution service (DDS is used to implement a data-centric common data bus for the smart grid. This common data bus improves the communication reliability, enabling distributed control and smart load management. These enhancements are achieved by avoiding a single point of failure while enabling peer-to-peer communication and an automatic discovery feature for dynamic participating nodes. The infrastructure and ideas presented in this paper were implemented and tested on the smart grid testbed. A toolbox and application programing interface for the testbed infrastructure are developed in order to facilitate interoperability and remote access to the testbed. This interface allows control, monitoring, and performing of experiments remotely. Furthermore, it could be used to integrate multidisciplinary testbeds to study complex cyber-physical systems (CPS.

Implementing earth observation and advanced satellite based atmospheric sounders for water resource and climate modelling

DEFF Research Database (Denmark)

Boegh, E.; Dellwik, Ebba; Hahmann, Andrea N.

2010-01-01

This paper discusses preliminary remote sensing (MODIS) based hydrological modelling results for the Danish island Sjælland (7330 km2) in relation to project objectives and methodologies of a new research project “Implementing Earth observation and advanced satellite based atmospheric sounders....... For this purpose, a) internal catchment processes will be studied using a Distributed Temperature Sensing (DTS) system, b) Earth observations will be used to upscale from field to regional scales, and c) at the largest scale, satellite based atmospheric sounders and meso-scale climate modelling will be used...

2-mm microwave interferometer

International Nuclear Information System (INIS)

Futch, A.H.; Mortensen, W.K.

1977-01-01

A 2-mm microwave interferometer has been developed, and phase shift measurements have been made on the Baseball II experiment. The interferometer system employs a 140-GHz receiver for double down conversion of the plasma signal to a 60-MHz, IF frequency. The 140-GHz references signal is also down-converted and compared with the plasma signal to provide the desired phase change of the signal passing through the plasma. A feedback voltage from a 60-MHz discriminator to a voltage-controlled oscillator in the receiver provides frequency stability of the 60-MHz IF signals

Development of the Advanced Technology Microwave Sounder (ATMS) for NPOESS C1

Science.gov (United States)

Brann, C.; Kunkee, D.

2008-12-01

The National Polar-orbiting Operational Environmental Satellite System's Advanced Technology Microwave Sounder (ATMS) is planned for flight on the first NPOESS mission (C1) in 2013. The C1 ATMS will be the second instrument of the ATMS series and will provide along with the companion Cross-track Infrared Sounder (CrIS), atmospheric temperature and moisture profiles for NPOESS. The first flight of the ATMS is scheduled in 2010 on the NPOESS Preparatory Project (NPP) satellite, which is an early instrument risk reduction component of the NPOESS mission. This poster will focus on the development of the ATMS for C1 including aspects of the sensor calibration, antenna beam and RF characteristics and scanning. New design aspects of the C1 ATMS, required primarily by parts obsolescence, will also be addressed in this poster.

Comparison of two matrix data structures for advanced CSM testbed applications

Science.gov (United States)

Regelbrugge, M. E.; Brogan, F. A.; Nour-Omid, B.; Rankin, C. C.; Wright, M. A.

1989-01-01

The first section describes data storage schemes presently used by the Computational Structural Mechanics (CSM) testbed sparse matrix facilities and similar skyline (profile) matrix facilities. The second section contains a discussion of certain features required for the implementation of particular advanced CSM algorithms, and how these features might be incorporated into the data storage schemes described previously. The third section presents recommendations, based on the discussions of the prior sections, for directing future CSM testbed development to provide necessary matrix facilities for advanced algorithm implementation and use. The objective is to lend insight into the matrix structures discussed and to help explain the process of evaluating alternative matrix data structures and utilities for subsequent use in the CSM testbed.

Optical-feedback semiconductor laser Michelson interferometer for displacement measurements with directional discrimination

International Nuclear Information System (INIS)

Rodrigo, Peter John; Lim, May; Saloma, Caesar

2001-01-01

An optical-feedback semiconductor laser Michelson interferometer (OSMI) is presented for measuring microscopic linear displacements without ambiguity in the direction of motion. The two waves from the interferometer arms, one from the reference mirror and the other from the reflecting moving target, are fed back into the lasing medium (λ=830 nm), causing variations in the laser output power. We model the OSMI into an equivalent Fabry-Perot resonator and derive the dependence of the output power (and the junction voltage) on the path difference between the two interferometer arms. Numerical and experimental results consistently show that the laser output power varies periodically (period, λ/2) with path difference. The output power variation exhibits an asymmetric behavior with the direction of motion, which is used to measure, at subwavelength resolution, the displacement vector (both amplitude and direction) of the moving sample. Two samples are considered in the experiments: (i) a piezoelectric transducer and (ii) an audio speaker

A generalized, periodic nonlinearity-reduced interferometer for straightness measurements

International Nuclear Information System (INIS)

Wu Chienming

2008-01-01

Periodic nonlinearity is a systematic error limiting the accuracy of displacement measurements at the nanometer level. However, an interferometer with a displacement measurement accuracy of less than 1 nm is required in nanometrology and in fundamental scientific research. To meet this requirement, a generalized, periodic nonlinearity-reduced interferometer, based on three construction principles has been developed for straightness measurements. These three construction principles have resulted in an interferometer with a highly stable design with reduced periodic nonlinearity. Verifications by a straightness interferometer have demonstrated that the periodic nonlinearity was less than 40 pm. The results also demonstrate that the interferometer design is capable of subnanometer accuracy and is useful in nanometrology

Mini-mast CSI testbed user's guide

Science.gov (United States)

Tanner, Sharon E.; Pappa, Richard S.; Sulla, Jeffrey L.; Elliott, Kenny B.; Miserentino, Robert; Bailey, James P.; Cooper, Paul A.; Williams, Boyd L., Jr.; Bruner, Anne M.

1992-01-01

The Mini-Mast testbed is a 20 m generic truss highly representative of future deployable trusses for space applications. It is fully instrumented for system identification and active vibrations control experiments and is used as a ground testbed at NASA-Langley. The facility has actuators and feedback sensors linked via fiber optic cables to the Advanced Real Time Simulation (ARTS) system, where user defined control laws are incorporated into generic controls software. The object of the facility is to conduct comprehensive active vibration control experiments on a dynamically realistic large space structure. A primary goal is to understand the practical effects of simplifying theoretical assumptions. This User's Guide describes the hardware and its primary components, the dynamic characteristics of the test article, the control law implementation process, and the necessary safeguards employed to protect the test article. Suggestions for a strawman controls experiment are also included.

The multichannel triple-laser interferometer/polarimeter system at RTP

NARCIS (Netherlands)

Rommers, J. H.; Donne, A. J. H.; Karelse, F. A.; Howard, J.

1997-01-01

yA 19-channel combined interferometer and polarimeter system has recently become operational at the Rijnhuizen Tokamak Project (a = 0.164 m, R = 0.72 m, B-tor less than or equal to 2.5 T, I-p less than or equal to 150 kA, plasma pulse duration less than or equal to 500 ms), in order to determine the

High-contrast imager for Complex Aperture Telescopes (HiCAT): testbed design and coronagraph developments

Science.gov (United States)

N'Diaye, Mamadou; Choquet, E.; Pueyo, L.; Elliot, E.; Perrin, M. D.; Wallace, J.; Anderson, R. E.; Carlotti, A.; Groff, T. D.; Hartig, G. F.; Kasdin, J.; Lajoie, C.; Levecq, O.; Long, C.; Macintosh, B.; Mawet, D.; Norman, C. A.; Shaklan, S.; Sheckells, M.; Sivaramakrishnan, A.; Soummer, R.

2014-01-01

We present a new high-contrast imaging testbed designed to provide complete solutions for wavefront sensing and control and starlight suppression with complex aperture telescopes (NASA APRA; Soummer PI). This includes geometries with central obstruction, support structures, and/or primary mirror segmentation. Complex aperture telescopes are often associated with large telescope designs, which are considered for future space missions. However, these designs makes high-contrast imaging challenging because of additional diffraction features in the point spread function. We present a novel optimization approach for the testbed optical and opto-mechanical design that minimizes the impact of both phase and amplitude errors from the wave propagation of testbed optics surface errors. This design approach allows us to define the specification for the bench optics, which we then compare to the manufactured parts. We discuss the testbed alignment and first results. We also present our coronagraph design for different testbed pupil shapes (AFTA or ATLAST), which involves a new method for the optimization of Apodized Pupil Lyot Coronagraphs (APLC).

Unequal-Arms Michelson Interferometers

Science.gov (United States)

Tinto, Massimo; Armstrong, J. W.

2000-01-01

Michelson interferometers allow phase measurements many orders of magnitude below the phase stability of the laser light injected into their two almost equal-length arms. If, however, the two arms are unequal, the laser fluctuations can not be removed by simply recombining the two beams. This is because the laser jitters experience different time delays in the two arms, and therefore can not cancel at the photo detector. We present here a method for achieving exact laser noise cancellation, even in an unequal-arm interferometer. The method presented in this paper requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. By linearly combining the two data sets with themselves, after they have been properly time shifted, we show that it is possible to construct a new data set that is free of laser fluctuations. An application of this technique to future planned space-based laser interferometer detector3 of gravitational radiation is discussed.

High accuracy step gauge interferometer

Science.gov (United States)

Byman, V.; Jaakkola, T.; Palosuo, I.; Lassila, A.

2018-05-01

Step gauges are convenient transfer standards for the calibration of coordinate measuring machines. A novel interferometer for step gauge calibrations implemented at VTT MIKES is described. The four-pass interferometer follows Abbe’s principle and measures the position of the inductive probe attached to a measuring head. The measuring head of the instrument is connected to a balanced boom above the carriage by a piezo translation stage. A key part of the measuring head is an invar structure on which the inductive probe and the corner cubes of the measuring arm of the interferometer are attached. The invar structure can be elevated so that the probe is raised without breaking the laser beam. During probing, the bending of the probe and the interferometer readings are recorded and the measurement face position is extrapolated to zero force. The measurement process is fully automated and the face positions of the steps can be measured up to a length of 2 m. Ambient conditions are measured continuously and the refractive index of air is compensated for. Before measurements the step gauge is aligned with an integrated 2D coordinate measuring system. The expanded uncertainty of step gauge calibration is U=\\sqrt{{{(64 nm)}2}+{{(88× {{10}-9}L)}2}} .

Michelson interferometer for measuring temperature

Science.gov (United States)

Xie, Dong; Xu, Chunling; Wang, An Min

2017-09-01

We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displaying Kerr nonlinearity. We obtain the analytical equations and numerically calculate the precision with parameters within the reach of current technology, proving that the precision of temperature can be greatly enhanced by using a nonlinear medium. Our results show that one can create an accurate thermometer by measuring the photons in the Michelson interferometer, with no need to directly measure the population of thermalized sample.

Use of Tabu Search in a Solver to Map Complex Networks onto Emulab Testbeds

National Research Council Canada - National Science Library

MacDonald, Jason E

2007-01-01

The University of Utah's solver for the testbed mapping problem uses a simulated annealing metaheuristic algorithm to map a researcher's experimental network topology onto available testbed resources...

Fiber Fabry-Perot interferometer with controllable temperature sensitivity.

Science.gov (United States)

Zhang, Xinpu; Peng, Wei; Zhang, Yang

2015-12-01

We proposed a fiber taper based on the Fabry-Perot (FP) interferometer structure with controllable temperature sensitivity. The FP interferometer is formed by inserting a segment of tapered fiber tip into the capillary and subsequently splicing the other end of the capillary to a single-mode fiber (SMF), the tapered fiber endface, and the spliced face form the FP cavity. Through controlling the inserted tapered fiber length, a series of FP interferometers were made. Because the inserted taper tip has the degree of freedom along the fiber axial, when the FP interferometer is subjected to temperature variation, the thermal expansion of the fiber taper tip will resist the FP cavity length change caused by the evolution of capillary length, and we can control the temperature sensitivity by adjusting the inserted taper length. In this structure, the equivalent thermal expansion coefficient of the FP interferometer can be defined; it was used to evaluate the temperature sensitivity of the FP interferometer, which provides an effective method to eliminate the temperature effect and to enhance other measurement accuracy. We fabricated the FP interferometers and calibrated their temperature characters by measuring the wavelength shift of the resonance dips in the reflection spectrum. In a temperature range of 50°C to 150°C, the corresponding temperature sensitivities can be controlled between 0 and 1.97 pm/°C when the inserted taper is between 75 and 160 μm. Because of its controllable temperature sensitivity, ease of fabrication, and low cost, this FP interferometer can meet different temperature sensitivity requirements in various application areas, especially in the fields which need temperature insensitivity.

Atom Wave Interferometers

National Research Council Canada - National Science Library

Pritchard, David

2000-01-01

Long-term research objective: Matter wave interferometers, in which de Broglie waves are coherently split and then recombined to produce interference fringes, have opened exciting new possibilities for precision and fundamental...

Development of a smart-antenna test-bed, demonstrating software defined digital beamforming

NARCIS (Netherlands)

Kluwer, T.; Slump, Cornelis H.; Schiphorst, Roelof; Hoeksema, F.W.

2001-01-01

This paper describes a smart-antenna test-bed consisting of ‘common of the shelf’ (COTS) hardware and software defined radio components. The use of software radio components enables a flexible platform to implement and test mobile communication systems as a real-world system. The test-bed is

Computerized lateral-shear interferometer

Science.gov (United States)

Hasegan, Sorin A.; Jianu, Angela; Vlad, Valentin I.

1998-07-01

A lateral-shear interferometer, coupled with a computer for laser wavefront analysis, is described. A CCD camera is used to transfer the fringe images through a frame-grabber into a PC. 3D phase maps are obtained by fringe pattern processing using a new algorithm for direct spatial reconstruction of the optical phase. The program describes phase maps by Zernike polynomials yielding an analytical description of the wavefront aberration. A compact lateral-shear interferometer has been built using a laser diode as light source, a CCD camera and a rechargeable battery supply, which allows measurements in-situ, if necessary.

Two-Particle Four-Mode Interferometer for Atoms

Science.gov (United States)

Dussarrat, Pierre; Perrier, Maxime; Imanaliev, Almazbek; Lopes, Raphael; Aspect, Alain; Cheneau, Marc; Boiron, Denis; Westbrook, Christoph I.

2017-10-01

We present a free-space interferometer to observe two-particle interference of a pair of atoms with entangled momenta. The source of atom pairs is a Bose-Einstein condensate subject to a dynamical instability, and the interferometer is realized using Bragg diffraction on optical lattices, in the spirit of our recent Hong-Ou-Mandel experiment. We report on an observation ruling out the possibility of a purely mixed state at the input of the interferometer. We explain how our current setup can be extended to enable a test of a Bell inequality on momentum observables.

Using the Talbot_Lau_interferometer_parameters Spreadsheet

Energy Technology Data Exchange (ETDEWEB)

Kallman, Jeffrey S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-06-04

Talbot-Lau interferometers allow incoherent X-ray sources to be used for phase contrast imaging. A spreadsheet for exploring the parameter space of Talbot and Talbot-Lau interferometers has been assembled. This spreadsheet allows the user to examine the consequences of choosing phase grating pitch, source energy, and source location on the overall geometry of a Talbot or Talbot-Lau X-ray interferometer. For the X-ray energies required to penetrate scanned luggage the spacing between gratings is large enough that the mechanical tolerances for amplitude grating positioning are unlikely to be met.

Fizeau plasma interferometer

International Nuclear Information System (INIS)

Frank, A.M.

1980-01-01

This paper describes a technique by which the sensitivity of plasma interferometers can be increased. Stabilization and fractional fringe measurement techniques have improved to the point where additional optical sensitivity could be useful

Michelson interferometer for measuring temperature

OpenAIRE

Xie, Dong; Xu, Chunling; wang, Anmin

2016-01-01

We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displa...

Closing the contrast gap between testbed and model prediction with WFIRST-CGI shaped pupil coronagraph

Science.gov (United States)

Zhou, Hanying; Nemati, Bijan; Krist, John; Cady, Eric; Prada, Camilo M.; Kern, Brian; Poberezhskiy, Ilya

2016-07-01

JPL has recently passed an important milestone in its technology development for a proposed NASA WFIRST mission coronagraph: demonstration of better than 1x10-8 contrast over broad bandwidth (10%) on both shaped pupil coronagraph (SPC) and hybrid Lyot coronagraph (HLC) testbeds with the WFIRST obscuration pattern. Challenges remain, however, in the technology readiness for the proposed mission. One is the discrepancies between the achieved contrasts on the testbeds and their corresponding model predictions. A series of testbed diagnoses and modeling activities were planned and carried out on the SPC testbed in order to close the gap. A very useful tool we developed was a derived "measured" testbed wavefront control Jacobian matrix that could be compared with the model-predicted "control" version that was used to generate the high contrast dark hole region in the image plane. The difference between these two is an estimate of the error in the control Jacobian. When the control matrix, which includes both amplitude and phase, was modified to reproduce the error, the simulated performance closely matched the SPC testbed behavior in both contrast floor and contrast convergence speed. This is a step closer toward model validation for high contrast coronagraphs. Further Jacobian analysis and modeling provided clues to the possible sources for the mismatch: DM misregistration and testbed optical wavefront error (WFE) and the deformable mirror (DM) setting for correcting this WFE. These analyses suggested that a high contrast coronagraph has a tight tolerance in the accuracy of its control Jacobian. Modifications to both testbed control model as well as prediction model are being implemented, and future works are discussed.

Toward a standard line for use in multibeam echo sounder calibration

Science.gov (United States)

Weber, Thomas C.; Rice, Glen; Smith, Michael

2018-06-01

A procedure is suggested in which a relative calibration for the intensity output of a multibeam echo sounder (MBES) can be performed. This procedure identifies a common survey line (i.e., a standard line), over which acoustic backscatter from the seafloor is collected with multiple MBES systems or by the same system multiple times. A location on the standard line which exhibits temporal stability in its seafloor backscatter response is used to bring the intensity output of the multiple MBES systems to a common reference. This relative calibration procedure has utility for MBES users wishing to generate an aggregate seafloor backscatter mosaic using multiple systems, revisiting an area to detect changes in substrate type, and comparing substrate types in the same general area but with different systems or different system settings. The calibration procedure is demonstrated using three different MBES systems over 3 different years in New Castle, NH, USA.

Heterodyne displacement interferometer, insensitive for input polarization

NARCIS (Netherlands)

Meskers, A.J.H.; Spronck, J.W.; Munnig Schmidt, R.H.

2014-01-01

Periodic nonlinearity (PNL) in displacement interferometers is a systematic error source that limits measurement accuracy. The PNL of coaxial heterodyne interferometers is highly influenced by the polarization state and orientation of the source frequencies. In this Letter, we investigate this error

Near-Infrared Keck Interferometer and IOTA Closure Phase Observations of Wolf-Rayet stars

Science.gov (United States)

Rajagopal, J.; Wallace, D.; Barry, R.; Richardson, L. J.; Traub, W.; Danchi, W. C.

We present first results from observations of a small sample of IR-bright Wolf-Rayet stars with the Keck Interferometer in the near-infrared, and with the IONIC beam three-telescope beam combiner at the Infrared and Optical Telescope Array (IOTA) observatory. The former results were obtained as part of shared-risk observations in commissioning the Keck Interferometer and form a subset of a high-resolution study of dust around Wolf-Rayet stars using multiple interferometers in progress in our group. The latter results are the first closure phase observations of these stars in the near-infrared in a separated telescope interferometer. Earlier aperture-masking observations with the Keck-I telescope provide strong evidence that dust-formation in late-type WC stars are a result of wind-wind collision in short-period binaries.Our program with the Keck interferometer seeks to further examine this paradigm at much higher resolution. We have spatially resolved the binary in the prototypical dusty WC type star WR 140. WR 137, another episodic dust-producing star, has been partially resolved for the first time, providing the first direct clue to its possible binary nature.We also include WN stars in our sample to investigate circumstellar dust in this other main sub-type of WRs. We have been unable to resolve any of these, indicating a lack of extended dust.Complementary observations using the MIDI instrument on the VLTI in the mid-infrared are presented in another contribution to this workshop.

The OGC Innovation Program Testbeds - Advancing Architectures for Earth and Systems

Science.gov (United States)

Bermudez, L. E.; Percivall, G.; Simonis, I.; Serich, S.

2017-12-01

The OGC Innovation Program provides a collaborative agile process for solving challenging science problems and advancing new technologies. Since 1999, 100 initiatives have taken place, from multi-million dollar testbeds to small interoperability experiments. During these initiatives, sponsors and technology implementers (including academia and private sector) come together to solve problems, produce prototypes, develop demonstrations, provide best practices, and advance the future of standards. This presentation will provide the latest system architectures that can be used for Earth and space systems as a result of the OGC Testbed 13, including the following components: Elastic cloud autoscaler for Earth Observations (EO) using a WPS in an ESGF hybrid climate data research platform. Accessibility of climate data for the scientist and non-scientist users via on demand models wrapped in WPS. Standards descriptions for containerize applications to discover processes on the cloud, including using linked data, a WPS extension for hybrid clouds and linking to hybrid big data stores. OpenID and OAuth to secure OGC Services with built-in Attribute Based Access Control (ABAC) infrastructures leveraging GeoDRM patterns. Publishing and access of vector tiles, including use of compression and attribute options reusing patterns from WMS, WMTS and WFS. Servers providing 3D Tiles and streaming of data, including Indexed 3d Scene Layer (I3S), CityGML and Common DataBase (CDB). Asynchronous Services with advanced pushed notifications strategies, with a filter language instead of simple topic subscriptions, that can be use across OGC services. Testbed 14 will continue advancing topics like Big Data, security, and streaming, as well as making easier to use OGC services (e.g. RESTful APIs). The Call for Participation will be issued in December and responses are due on mid January 2018.

Physical interpretation of the fringe shift measured on Michelson interferometer in optical media

International Nuclear Information System (INIS)

Demjanov, V.V.

2010-01-01

The shift of the interference fringe in the Michelson interferometer is absent in vacuum but present in measurements performed in dielectric media with the refractive index greater than unity. This experimental observation induced me to interpret physical processes occurred in the Michelson interferometer in a conceptually new way. I rejected the generally accepted additive rule c±v for composition of the velocity v of the inertial body and the speed c of light as inapplicable in principle to non-inertial objects which electromagnetic waves just belong to. I used instead the non-relativistic formula of Fresnel for drag of light by a moving optical medium. This formula, and taking into account the physical effect of Lorentz contraction of the arm of interferometer, enabled me to construct the theoretical model that reproduces in essential features the parabolic dependence of the shift of the interference fringe on the dielectric permittivity of the light-carrying material. The Earth's speed relative to aether found from the experimental curve was estimated as 140-480 km/s. The range of the values refers to the projection of the speed on the horizontal plane of the experimental setup measured at various time of day and night.

ISIS Topside-Sounder Plasma-Wave Investigations as Guides to Desired Virtual Wave Observatory (VWO) Data Search Capabilities

Science.gov (United States)

Benson, Robert F.; Fung, Shing F.

2008-01-01

Many plasma-wave phenomena, observed by space-borne radio sounders, cannot be properly explained in terms of wave propagation in a cold plasma consisting of mobile electrons and infinitely massive positive ions. These phenomena include signals known as plasma resonances. The principal resonances at the harmonics of the electron cyclotron frequency, the plasma frequency, and the upper-hybrid frequency are well explained by the warm-plasma propagation of sounder-generated electrostatic waves, Other resonances have been attributed to sounder-stimulated plasma instability and non-linear effects, eigenmodes of cylindrical electromagnetic plasma oscillations, and plasma memory processes. Data from the topside sounders of the International Satellites for Ionospheric Studies (ISIS) program played a major role in these interpretations. A data transformation and preservation effort at the Goddard Space Flight Center has produced digital ISIS topside ionograms and a metadata search program that has enabled some recent discoveries pertaining to the physics of these plasma resonances. For example, data records were obtained that enabled the long-standing question (several decades) of the origin of the plasma resonance at the fundamental electron cyclotron frequency to be explained [Muldrew, Radio Sci., 2006]. These data-search capabilities, and the science enabled by them, will be presented as a guide to desired data search capabilities to be included in the Virtual Wave Observatory (VWO).

Step index fibre using laser interferometer

Indian Academy of Sciences (India)

2014-03-04

Mar 4, 2014 ... We propose the following model to describe the cladded fibre placed inside a liquid wedge interferometer. For simplicity, we assume square interferometer plates of dimensions 2a,. 2b and refractive index μL. The fibre radius is rf and the core radius is rc with skin and core indices μs, μc respectively. Hence ...

Algorithms for Unequal-Arm Michelson Interferometers

Science.gov (United States)

Giampieri, Giacomo; Hellings, Ronald W.; Tinto, Massimo; Bender, Peter L.; Faller, James E.

1994-01-01

A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam.

Definition study for variable cycle engine testbed engine and associated test program

Science.gov (United States)

Vdoviak, J. W.

1978-01-01

The product/study double bypass variable cycle engine (VCE) was updated to incorporate recent improvements. The effect of these improvements on mission range and noise levels was determined. This engine design was then compared with current existing high-technology core engines in order to define a subscale testbed configuration that simulated many of the critical technology features of the product/study VCE. Detailed preliminary program plans were then developed for the design, fabrication, and static test of the selected testbed engine configuration. These plans included estimated costs and schedules for the detail design, fabrication and test of the testbed engine and the definition of a test program, test plan, schedule, instrumentation, and test stand requirements.

102(ℎ/2π)k Large Area Atom Interferometers

International Nuclear Information System (INIS)

Chiow, Sheng-wey; Kovachy, Tim; Chien, Hui-Chun; Kasevich, Mark A.

2011-01-01

We demonstrate atom interferometers utilizing a novel beam splitter based on sequential multiphoton Bragg diffractions. With this sequential Bragg large momentum transfer (SB-LMT) beam splitter, we achieve high contrast atom interferometers with momentum splittings of up to 102 photon recoil momenta (102(ℎ/2π)k). To our knowledge, this is the highest momentum splitting achieved in any atom interferometer, advancing the state-of-the-art by an order of magnitude. We also demonstrate strong noise correlation between two simultaneous SB-LMT interferometers, which alleviates the need for ultralow noise lasers and ultrastable inertial environments in some future applications. Our method is intrinsically scalable and can be used to dramatically increase the sensitivity of atom interferometers in a wide range of applications, including inertial sensing, measuring the fine structure constant, and detecting gravitational waves.

University of Florida Advanced Technologies Campus Testbed

Science.gov (United States)

2017-09-21

The University of Florida (UF) and its Transportation Institute (UFTI), the Florida Department of Transportation (FDOT) and the City of Gainesville (CoG) are cooperating to develop a smart transportation testbed on the University of Florida (UF) main...

NBodyLab: A Testbed for Undergraduates Utilizing a Web Interface to NEMO and MD-GRAPE2 Hardware

Science.gov (United States)

Johnson, V. L.; Teuben, P. J.; Penprase, B. E.

An N-body simulation testbed called NBodyLab was developed at Pomona College as a teaching tool for undergraduates. The testbed runs under Linux and provides a web interface to selected back-end NEMO modeling and analysis tools, and several integration methods which can optionally use an MD-GRAPE2 supercomputer card in the server to accelerate calculation of particle-particle forces. The testbed provides a framework for using and experimenting with the main components of N-body simulations: data models and transformations, numerical integration of the equations of motion, analysis and visualization products, and acceleration techniques (in this case, special purpose hardware). The testbed can be used by students with no knowledge of programming or Unix, freeing such students and their instructor to spend more time on scientific experimentation. The advanced student can extend the testbed software and/or more quickly transition to the use of more advanced Unix-based toolsets such as NEMO, Starlab and model builders such as GalactICS. Cosmology students at Pomona College used the testbed to study collisions of galaxies with different speeds, masses, densities, collision angles, angular momentum, etc., attempting to simulate, for example, the Tadpole Galaxy and the Antenna Galaxies. The testbed framework is available as open-source to assist other researchers and educators. Recommendations are made for testbed enhancements.

Experimental implementation of phase locking in a nonlinear interferometer

Energy Technology Data Exchange (ETDEWEB)

Wang, Hailong; Jing, Jietai, E-mail: jtjing@phy.ecnu.edu.cn [State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062 (China); Marino, A. M. [Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 West Brooks Street, Norman, Oklahoma 73019 (United States)

2015-09-21

Based upon two cascade four-wave mixing processes in two identical hot rubidium vapor cells, a nonlinear interferometer has been experimentally realized [Jing et al., Appl. Phys. Lett. 99, 011110 (2011); Hudelist et al., Nat. Commun. 5, 3049 (2014)]. It has a higher degree of phase sensitivity than a traditional linear interferometer and has many potential applications in quantum metrology. Phase locking of the nonlinear interferometer is needed before it can find its way into applications. In this letter, we investigate the experimental implementation of phase locking of the relative phase between the three beams at different frequencies involved in such a nonlinear interferometer. We have utilized two different methods, namely, beat note locking and coherent modulation locking. We find that coherent modulation locking can achieve much better phase stability than beat note locking in our system. Our results pave the way for real applications of a nonlinear interferometer in precision measurement and quantum manipulation, for example, phase control in phase-sensitive N-wave mixing process, N-port nonlinear interferometer and quantum-enhanced real-time phase tracking.

LTP interferometer-noise sources and performance

International Nuclear Information System (INIS)

Robertson, David; Killow, Christian; Ward, Harry; Hough, Jim; Heinzel, Gerhard; Garcia, Antonio; Wand, Vinzenz; Johann, Ulrich; Braxmaier, Claus

2005-01-01

The LISA Technology Package (LTP) uses laser interferometry to measure the changes in relative displacement between two inertial test masses. The goals of the mission require a displacement measuring precision of 10 pm Hz -1/2 at frequencies in the 3-30 mHz band. We report on progress with a prototype LTP interferometer optical bench in which fused silica mirrors and beamsplitters are fixed to a ZERODUR (registered) substrate using hydroxide catalysis bonding to form a rigid interferometer. The couplings to displacement noise of this interferometer of two expected noise sources-laser frequency noise and ambient temperature fluctuations-have been investigated, and an additional, unexpected, noise source has been identified. The additional noise is due to small amounts of signal at the heterodyne frequency arriving at the photodiode preamplifiers with a phase that quasistatically changes with respect to the optical signal. The phase shift is caused by differential changes in the external optical paths the beams travel before they reach the rigid interferometer. Two different external path length stabilization systems have been demonstrated and these allowed the performance of the overall system to meet the LTP displacement noise requirement

Michelson Interferometer

Science.gov (United States)

Rogers, Ryan

2007-01-01

The Michelson Interferometer is a device used in many applications, but here it was used to measure small differences in distance, in the milli-inch range, specifically for defects in the Orbiter windows. In this paper, the method of using the Michelson Interferometer for measuring small distances is explained as well as the mathematics of the system. The coherence length of several light sources was calculated in order to see just how small a defect could be measured. Since white light is a very broadband source, its coherence length is very short and thus can be used to measure small defects in glass. After finding the front and back reflections from a very thin glass slide with ease and calculating the thickness of it very accurately, it was concluded that this system could find and measure small defects on the Orbiter windows. This report also discusses a failed attempt for another use of this technology as well as describes an area of promise for further analysis. The latter of these areas has applications for finding possible defects in Orbiter windows without moving parts.

Optical Network Testbeds Workshop

Energy Technology Data Exchange (ETDEWEB)

Joe Mambretti

2007-06-01

This is the summary report of the third annual Optical Networking Testbed Workshop (ONT3), which brought together leading members of the international advanced research community to address major challenges in creating next generation communication services and technologies. Networking research and development (R&D) communities throughout the world continue to discover new methods and technologies that are enabling breakthroughs in advanced communications. These discoveries are keystones for building the foundation of the future economy, which requires the sophisticated management of extremely large qualities of digital information through high performance communications. This innovation is made possible by basic research and experiments within laboratories and on specialized testbeds. Initial network research and development initiatives are driven by diverse motives, including attempts to solve existing complex problems, the desire to create powerful new technologies that do not exist using traditional methods, and the need to create tools to address specific challenges, including those mandated by large scale science or government agency mission agendas. Many new discoveries related to communications technologies transition to wide-spread deployment through standards organizations and commercialization. These transition paths allow for new communications capabilities that drive many sectors of the digital economy. In the last few years, networking R&D has increasingly focused on advancing multiple new capabilities enabled by next generation optical networking. Both US Federal networking R&D and other national R&D initiatives, such as those organized by the National Institute of Information and Communications Technology (NICT) of Japan are creating optical networking technologies that allow for new, powerful communication services. Among the most promising services are those based on new types of multi-service or hybrid networks, which use new optical networking

Context-aware local Intrusion Detection in SCADA systems : a testbed and two showcases

NARCIS (Netherlands)

Chromik, Justyna Joanna; Haverkort, Boudewijn R.H.M.; Remke, Anne Katharina Ingrid; Pilch, Carina; Brackmann, Pascal; Duhme, Christof; Everinghoff, Franziska; Giberlein, Artur; Teodorowicz, Thomas; Wieland, Julian

2017-01-01

This paper illustrates the use of a testbed that we have developed for context-aware local intrusion detection. This testbed is based on the co-simulation framework Mosaik and allows for the validation of local intrusion detection mechanisms at field stations in power distribution networks. For two

Wave–particle duality in a Raman atom interferometer

International Nuclear Information System (INIS)

Jia Ai-Ai; Yang Jun; Yan Shu-Hua; Hu Qing-Qing; Luo Yu-Kun; Zhu Shi-Yao

2015-01-01

We theoretically investigate the wave–particle duality based on a Raman atom interferometer, via the interaction between the atom and Raman laser, which is similar to the optical Mach–Zehnder interferometer. The wave and which-way information are stored in the atomic internal states. For the φ − π − π/2 type of atom interferometer, we find that the visibility (V) and predictability (P) still satisfy the duality relation, P 2 + V 2 ≤ 1. (paper)

The effect of rotations on Michelson interferometers

Energy Technology Data Exchange (ETDEWEB)

Maraner, Paolo, E-mail: pmaraner@unibz.it

2014-11-15

In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations.

The effect of rotations on Michelson interferometers

International Nuclear Information System (INIS)

Maraner, Paolo

2014-01-01

In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations

An adaptable, low cost test-bed for unmanned vehicle systems research

Science.gov (United States)

Goppert, James M.

2011-12-01

An unmanned vehicle systems test-bed has been developed. The test-bed has been designed to accommodate hardware changes and various vehicle types and algorithms. The creation of this test-bed allows research teams to focus on algorithm development and employ a common well-tested experimental framework. The ArduPilotOne autopilot was developed to provide the necessary level of abstraction for multiple vehicle types. The autopilot was also designed to be highly integrated with the Mavlink protocol for Micro Air Vehicle (MAV) communication. Mavlink is the native protocol for QGroundControl, a MAV ground control program. Features were added to QGroundControl to accommodate outdoor usage. Next, the Mavsim toolbox was developed for Scicoslab to allow hardware-in-the-loop testing, control design and analysis, and estimation algorithm testing and verification. In order to obtain linear models of aircraft dynamics, the JSBSim flight dynamics engine was extended to use a probabilistic Nelder-Mead simplex method. The JSBSim aircraft dynamics were compared with wind-tunnel data collected. Finally, a structured methodology for successive loop closure control design is proposed. This methodology is demonstrated along with the rest of the test-bed tools on a quadrotor, a fixed wing RC plane, and a ground vehicle. Test results for the ground vehicle are presented.

Six-channel adaptive fibre-optic interferometer

Energy Technology Data Exchange (ETDEWEB)

Romashko, R V; Bezruk, M N; Kamshilin, A A; Kulchin, Yurii N

2012-06-30

We have proposed and analysed a scheme for the multiplexing of orthogonal dynamic holograms in photorefractive crystals which ensures almost zero cross talk between the holographic channels upon phase demodulation. A six-channel adaptive fibre-optic interferometer was built, and the detection limit for small phase fluctuations in the channels of the interferometer was determined to be 2.1 Multiplication-Sign 10{sup -8} rad W{sup 1/2} Hz{sup -1/2}. The channel multiplexing capacity of the interferometer was estimated. The formation of 70 channels such that their optical fields completely overlap in the crystal reduces the relative detection limit in the working channel by just 10 %. We found conditions under which the maximum cross talk between the channels was within the intrinsic noise level in the channels (-47 dB).

Cooperative Search with Autonomous Vehicles in a 3D Aquatic Testbed

Science.gov (United States)

2012-01-01

Cooperative Search with Autonomous Vehicles in a 3D Aquatic Testbed Matthew Keeter1, Daniel Moore2,3, Ryan Muller2,3, Eric Nieters1, Jennifer...Many applications for autonomous vehicles involve three-dimensional domains, notably aerial and aquatic environments. Such applications include mon...TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Cooperative Search With Autonomous Vehicles In A 3D Aquatic Testbed 5a

PEER Testbed Study on a Laboratory Building: Exercising Seismic Performance Assessment

OpenAIRE

Comerio, Mary C.; Stallmeyer, John C.; Smith, Ryan; Makris, Nicos; Konstantinidis, Dimitrios; Mosalam, Khalid; Lee, Tae-Hyung; Beck, James L.; Porter, Keith A.; Shaikhutdinov, Rustem; Hutchinson, Tara; Chaudhuri, Samit Ray; Chang, Stephanie E.; Falit-Baiamonte, Anthony; Holmes, William T.

2005-01-01

From 2002 to 2004 (years five and six of a ten-year funding cycle), the PEER Center organized the majority of its research around six testbeds. Two buildings and two bridges, a campus, and a transportation network were selected as case studies to “exercise” the PEER performance-based earthquake engineering methodology. All projects involved interdisciplinary teams of researchers, each producing data to be used by other colleagues in their research. The testbeds demonstrat...

Decorrelation and fringe visibility: On the limiting behavior of varous electronic speckle pattern correlation interferometers

DEFF Research Database (Denmark)

Owner-Petersen, Mette

1996-01-01

I discuss the behavior of fringe formation in image-plane electronic speckle-pattern correlation interferometers as the limit of total decorrelation is approached. The interferometers are supposed to operate in the difference mode. The effect of decorrelation will be a decrease in fringe visibility...... until the limit of total decorrelation, when no fringes will be formed, is reached. A quantitative evaluation of the partially decorrelated fringe pattern is presented for the case of decorrelation due to both tilt and in-plane translation of an object surface element. It is shown that the fringe...

Vibrometer based on a self-mixing effect interferometer

International Nuclear Information System (INIS)

Marti-Lopez, Luis; Gonzalez-Penna, R.; Martinez-Celorio, R. A.

2009-01-01

We outline the basic principles of the self-mixing effect and present the design and construction of an interferometer based on this phenomenon. It differs from the previously reported in the literature by the use of two photodetectors, located at different arms of the interferometer. This feature allows widening the arsenal of strategies for the digital processing of the signal. The interferometer is used as vibrometer for the characterization of professional loudspeakers. Experimental results are presented as an illustration. (Author)

Gravitational Wave Detection with Single-Laser Atom Interferometers

Science.gov (United States)

Yu, Nan; Tinto, Massimo

2011-01-01

A new design for a broadband detector of gravitational radiation relies on two atom interferometers separated by a distance L. In this scheme, only one arm and one laser are used for operating the two atom interferometers. The innovation here involves the fact that the atoms in the atom interferometers are not only considered as perfect test masses, but also as highly stable clocks. Atomic coherence is intrinsically stable, and can be many orders of magnitude more stable than a laser.

Special topics in infrared interferometry. [Michelson interferometer development

Science.gov (United States)

Hanel, R. A.

1985-01-01

Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

Modular Algorithm Testbed Suite (MATS): A Software Framework for Automatic Target Recognition

Science.gov (United States)

2017-01-01

NAVAL SURFACE WARFARE CENTER PANAMA CITY DIVISION PANAMA CITY, FL 32407-7001 TECHNICAL REPORT NSWC PCD TR-2017-004 MODULAR ...31-01-2017 Technical Modular Algorithm Testbed Suite (MATS): A Software Framework for Automatic Target Recognition DR...flexible platform to facilitate the development and testing of ATR algorithms. To that end, NSWC PCD has created the Modular Algorithm Testbed Suite

Demonstration of a robust magnonic spin wave interferometer.

Science.gov (United States)

Kanazawa, Naoki; Goto, Taichi; Sekiguchi, Koji; Granovsky, Alexander B; Ross, Caroline A; Takagi, Hiroyuki; Nakamura, Yuichi; Inoue, Mitsuteru

2016-07-22

Magnonics is an emerging field dealing with ultralow power consumption logic circuits, in which the flow of spin waves, rather than electric charges, transmits and processes information. Waves, including spin waves, excel at encoding information via their phase using interference. This enables a number of inputs to be processed in one device, which offers the promise of multi-input multi-output logic gates. To realize such an integrated device, it is essential to demonstrate spin wave interferometers using spatially isotropic spin waves with high operational stability. However, spin wave reflection at the waveguide edge has previously limited the stability of interfering waves, precluding the use of isotropic spin waves, i.e., forward volume waves. Here, a spin wave absorber is demonstrated comprising a yttrium iron garnet waveguide partially covered by gold. This device is shown experimentally to be a robust spin wave interferometer using the forward volume mode, with a large ON/OFF isolation value of 13.7 dB even in magnetic fields over 30 Oe.

A global climatology of stratospheric gravity waves from Atmospheric Infrared Sounder observations

Science.gov (United States)

Hoffmann, Lars; Xue, Xianghui; Alexander, M. Joan

2014-05-01

We present the results of a new study that aims on the detection and classification of `hotspots' of stratospheric gravity waves on a global scale. The analysis is based on a nine-year record (2003 to 2011) of radiance measurements by the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite. We detect the presence of stratospheric gravity waves based on 4.3 micron brightness temperature variances. Our method is optimized for peak events, i.e., strong gravity wave events for which the local variance considerably exceeds background levels. We estimated the occurrence frequencies of these peak events for different seasons and time of day and used the results to find local maxima of gravity wave activity. In addition, we use AIRS radiances at 8.1 micron to simultaneously detect convective events, including deep convection in the tropics and mesoscale convective systems at mid latitudes. We classified the gravity waves according to their sources, based on seasonal occurrence frequencies for convection and by means of topographic data. Our study reproduces well-known hotspots of gravity waves, e.g., the mountain wave hotspots at the Andes and the Antarctic Peninsula or the convective hotspot during the thunderstorm season over the North American Great Plains. However, the high horizontal resolution of the AIRS observations also helped us to locate several smaller hotspots, which were partly unknown or poorly studied so far. Most of these smaller hotspots are found near orographic features like small mountain ranges, in coastal regions, in desert areas, or near isolated islands. This new study will help to select the most promising regions and seasons for future observational studies of gravity waves. Reference: Hoffmann, L., X. Xue, and M. J. Alexander, A global view of stratospheric gravity wave hotspots located with Atmospheric Infrared Sounder observations, J. Geophys. Res., 118, 416-434, doi:10.1029/2012JD018658, 2013.

Superconducting on-chip microwave interferometers

Energy Technology Data Exchange (ETDEWEB)

Menzel, Edwin P.; Fischer, Michael; Schneider, Christian; Baust, Alexander; Eder, Peter; Goetz, Jan; Haeberlein, Max; Schwarz, Manuel; Wulschner, Karl Friedrich; Xie, Edwar; Zhong, Ling; Deppe, Frank; Fedorov, Kirill; Huebl, Hans; Marx, Achim; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany)

2015-07-01

In the realm of all-microwave quantum computation, information is encoded in itinerant microwave photons propagating along transmission lines. In such a system unitary operations are implemented by linear elements such as beam splitters or interferometers. However, for two-qubit operations non-linear gates, e.g., c-phase gates are required. In this work, we investigate superconducting interferometers as a building block of a c-phase gate. We experimentally characterize their scattering properties and compare them to simulation results. Finally, we discuss our progress towards the realization of a c-phase gate.

The Living With a Star Space Environment Testbed Program

Science.gov (United States)

Barth, Janet; LaBel, Kenneth; Day, John H. (Technical Monitor)

2001-01-01

NASA has initiated the Living with a Star (LWS) Program to develop the scientific understanding to address the aspects of the Connected Sun-Earth system that affects life and society. The Program Architecture includes science missions, theory and modeling and Space Environment Testbeds (SET). This current paper discusses the Space Environment Testbeds. The goal of the SET program is to improve the engineering approach to accomodate and/or mitigate the effects of solar variability on spacecraft design and operations. The SET Program will infuse new technologies into the space programs through collection of data in space and subsequent design and validation of technologies. Examples of these technologies are cited and discussed.

A double-pass interferometer for measurement of dimensional changes

International Nuclear Information System (INIS)

Ren, Dongmei; Lawton, K M; Miller, J A

2008-01-01

A double-pass interferometer was developed for measuring dimensional changes of materials in a nanoscale absolute interferometric dilatometer. This interferometer realized the double-ended measurement of a sample using a single-detection double-pass interference system. The nearly balanced design, in which the measurement beam and the reference beam have equal optical path lengths except for the path difference caused by the sample itself, makes this interferometer have high stability, which is verified by the measurement of a quasi-zero-length sample. The preliminary experiments and uncertainty analysis show that this interferometer should be able to measure dimensional changes with characteristic uncertainty at the nanometer level

Diffraction-based analysis of tunnel size for a scaled external occulter testbed

Science.gov (United States)

Sirbu, Dan; Kasdin, N. Jeremy; Vanderbei, Robert J.

2016-07-01

For performance verification of an external occulter mask (also called a starshade), scaled testbeds have been developed to measure the suppression of the occulter shadow in the pupil plane and contrast in the image plane. For occulter experiments the scaling is typically performed by maintaining an equivalent Fresnel number. The original Princeton occulter testbed was oversized with respect to both input beam and shadow propagation to limit any diffraction effects due to finite testbed enclosure edges; however, to operate at realistic space-mission equivalent Fresnel numbers an extended testbed is currently under construction. With the longer propagation distances involved, diffraction effects due to the edge of the tunnel must now be considered in the experiment design. Here, we present a diffraction-based model of two separate tunnel effects. First, we consider the effect of tunnel-edge induced diffraction ringing upstream from the occulter mask. Second, we consider the diffraction effect due to clipping of the output shadow by the tunnel downstream from the occulter mask. These calculations are performed for a representative point design relevant to the new Princeton occulter experiment, but we also present an analytical relation that can be used for other propagation distances.

High Resolution Infrared Radiation Sounder (HIRS) for the Nimbus F Spacecraft

Science.gov (United States)

Koenig, E. W.

1975-01-01

Flown on Nimbus F in June 1975, the high resolution infrared radiation sounder (HIRS) scans with a geographical resolution of 23KM and samples radiance in seventeen selected spectral channels from visible (.7 micron) to far IR (15 micron). Vertical temperature profiles and atmospheric moisture content can be inferred from the output. System operation and test results are described.

An absolute distance interferometer with two external cavity diode lasers

International Nuclear Information System (INIS)

Hartmann, L; Meiners-Hagen, K; Abou-Zeid, A

2008-01-01

An absolute interferometer for length measurements in the range of several metres has been developed. The use of two external cavity diode lasers allows the implementation of a two-step procedure which combines the length measurement with a variable synthetic wavelength and its interpolation with a fixed synthetic wavelength. This synthetic wavelength is obtained at ≈42 µm by a modulation-free stabilization of both lasers to Doppler-reduced rubidium absorption lines. A stable reference interferometer is used as length standard. Different contributions to the total measurement uncertainty are discussed. It is shown that the measurement uncertainty can considerably be reduced by correcting the influence of vibrations on the measurement result and by applying linear regression to the quadrature signals of the absolute interferometer and the reference interferometer. The comparison of the absolute interferometer with a counting interferometer for distances up to 2 m results in a linearity error of 0.4 µm in good agreement with an estimation of the measurement uncertainty

Implementation of a virtual link between power system testbeds at Marshall Spaceflight Center and Lewis Research Center

Science.gov (United States)

Doreswamy, Rajiv

1990-01-01

The Marshall Space Flight Center (MSFC) owns and operates a space station module power management and distribution (SSM-PMAD) testbed. This system, managed by expert systems, is used to analyze and develop power system automation techniques for Space Station Freedom. The Lewis Research Center (LeRC), Cleveland, Ohio, has developed and implemented a space station electrical power system (EPS) testbed. This system and its power management controller are representative of the overall Space Station Freedom power system. A virtual link is being implemented between the testbeds at MSFC and LeRC. This link would enable configuration of SSM-PMAD as a load center for the EPS testbed at LeRC. This connection will add to the versatility of both systems, and provide an environment of enhanced realism for operation of both testbeds.

An Assessment of Data from the Advanced Technology Microwave Sounder at the Met Office

Directory of Open Access Journals (Sweden)

Amy Doherty

2015-01-01

Full Text Available An appraisal of the Advanced Technology Microwave Sounder (ATMS for use in numerical weather prediction (NWP is presented, including an assessment of the data quality, the impact on Met Office global forecasts in preoperational trials, and a summary of performance over a period of 17 months operational use. After remapping, the noise performance (NEΔT of the tropospheric temperature sounding channels is evaluated to be approximately 0.1 K, comparing favourably with AMSU-A. However, the noise is not random, differences between observations and simulations based on short-range forecast fields show a spurious striping effect, due to 1/f noise in the receiver. The amplitude of this signal is several tenths of a Kelvin, potentially a concern for NWP applications. In preoperational tests, adding ATMS data to a full Met Office system already exploiting data from four microwave sounders improves southern hemisphere mean sea level pressure forecasts in the 2- to 5-day range by 1-2%. In operational use, where data from five other microwave sounders is assimilated, forecast impact is typically between −0.05 and −0.1 J/kg (3.4% of total mean impact per day over the period 1 April to 31 July 2013. This suggests benefits beyond redundancy, associated with reducing already small analysis errors.

Measuring tropospheric wind with microwave sounders

Science.gov (United States)

Lambrigtsen, B.; Su, H.; Turk, J.; Hristova-Veleva, S. M.; Dang, V. T.

2017-12-01

In its 2007 "Decadal Survey" of earth science missions for NASA the U.S. National Research Council recommended that a Doppler wind lidar be developed for a three-dimensional tropospheric winds mission ("3D-Winds"). The technology required for such a mission has not yet been developed, and it is expected that the next Decadal Survey, planned to be released by the end of 2017, will put additional emphasis on the still pressing need for wind measurements from space. The first Decadal Survey also called for a geostationary microwave sounder (GMS) on a Precipitation and All-weather Temperature and Humidity (PATH) mission, which could be used to measure wind from space. Such a sounder, the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR), has been developed at the Jet Propulsion Laboratory (JPL). The PATH mission has not yet been funded by NASA, but a low-cost subset of PATH, GeoStorm has been proposed as a hosted payload on a commercial communications satellite. Both PATH and GeoStorm would obtain frequent (every 15 minutes of better) measurements of tropospheric water vapor profiles, and they can be used to derive atmospheric motion vector (AMV) wind profiles, even in the presence of clouds. Measurement of wind is particularly important in the tropics, where the atmosphere is largely not in thermal balance and wind estimates cannot generally be derived from temperature and pressure fields. We report on simulation studies of AMV wind vectors derived from a GMS and from a cluster of low-earth-orbiting (LEO) small satellites (e.g., CubeSats). The results of two separate simulation studies are very encouraging and show that a ±2 m/s wind speed precision is attainable, which would satisfy WMO requirements. A GMS observing system in particular, which can be implemented now, would enable significant progress in the study of atmospheric dynamics. Copyright 2017 California Institute of Technology. Government sponsorship acknowledged

Dual-recycled cavity-enhanced Michelson interferometer for gravitational-wave detection.

Science.gov (United States)

Müller, Guido; Delker, Tom; Tanner, David B; Reitze, David

2003-03-01

The baseline design for an Advanced Laser Interferometer Gravitational-Wave Observatory (Advanced LIGO) is a dual-recycled Michelson interferometer with cavities in each of the Michelson interferometer arms. We describe one possible length-sensing and control scheme for such a dual-recycled, cavity-enhanced Michelson interferometer. We discuss the principles of this scheme and derive the first-order sensing signals. We also present a successful experimental verification of our length-sensing system using a prototype tabletop interferometer. Our results demonstrate the robustness of the scheme against deviations from the idealized design. We also identify potential weaknesses and discuss possible improvements. These results as well as other benchtop experiments that we present form the basis for a sensing and control scheme for Advanced LIGO.

Polydyne displacement interferometer using frequency-modulated light

Science.gov (United States)

Arablu, Masoud; Smith, Stuart T.

2018-05-01

A radio-frequency Frequency-Modulated (FM) signal is used to diffract a He-Ne laser beam through an Acousto-Optic Modulator (AOM). Due to the modulation of the FM signal, the measured spectra of the diffracted beams comprise a series of phase-synchronized harmonics that have exact integer frequency separation. The first diffraction side-beam emerging from the AOM is selected by a slit to be used in a polydyne displacement interferometer in a Michelson interferometer topology. The displacement measurement is derived from the phase measurement of selected modulation harmonic pairs. Individual harmonic frequency amplitudes are measured using discrete Fourier transform applied to the signal from a single photodetector. Phase signals are derived from the changes in the amplitudes of different harmonic pairs (typically odd-even pairs) with the phase being extracted using a standard quadrature method. In this study, two different modulation frequencies of 5 and 10 kHz are used at different modulation depths. The measured displacements by different harmonic pairs are compared with a commercial heterodyne interferometer being used as a reference for these studies. Measurements obtained from five different harmonic pairs when the moving mirror of the interferometer is scanned over ranges up to 10 μm all show differences of less than 50 nm from the reference interferometer measurements. A drift test was also used to evaluate the differences between the polydyne interferometer and reference measurements that had different optical path lengths of approximately 25 mm and 50 mm, respectively. The drift test results indicate that about half of the differences can be attributed to temperature, pressure, and humidity variations. Other influences include Abbe and thermal expansion effects. Rough magnitude estimates using simple models for these two effects can account for remaining observed deviations.

NOAA JPSS Advanced Technology Microwave Sounder (ATMS)-based Tropical Cyclone (TC) Products from NDE

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The JPSS Microwave Sounder-based Tropical Cyclone (TC) Products provide estimates of tropical cyclone maximum wind speed, minimum sea level pressure, radii of 34,...

Science Study For A Low Cost Upper Atmosphere Sounder (LOCUS)

Science.gov (United States)

Gerber, D.; Swinyard, B. M.; Ellison, B. N.; Siddans, R.; Kerridge, B. J.; Plane, J. M. C.; Feng, W.

2013-12-01

We present the findings of an initial science study to define the spectral bands for the proposed Mesosphere / Lower Thermosphere (MLT) sounder LOCUS. The LOCUS mission (Fig 1) uses disruptive technologies to make key MLT species detectable globally by satellite remote sensing for the first time. This presentation summarises the technological and scientific foundation on which the current 4-band Terahertz (THz) and sub- millimetre wave (SMW) instrument configuration was conceived.

Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)

Science.gov (United States)

Roberts, B.

1986-01-01

The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

Advanced Gouy phase high harmonics interferometer

Science.gov (United States)

Mustary, M. H.; Laban, D. E.; Wood, J. B. O.; Palmer, A. J.; Holdsworth, J.; Litvinyuk, I. V.; Sang, R. T.

2018-05-01

We describe an extreme ultraviolet (XUV) interferometric technique that can resolve ∼100 zeptoseconds (10‑21 s) delay between high harmonic emissions from two successive sources separated spatially along the laser propagation in a single Gaussian beam focus. Several improvements on our earlier work have been implemented in the advanced interferometer. In this paper, we report on the design, characterization and optimization of the advanced Gouy phase interferometer. Temporal coherence for both atomic argon and molecular hydrogen gases has been observed for several harmonic orders. It has been shown that phase shift of XUV pulses mainly originates from the emission time delay due to the Gouy phase in the laser focus and the observed interference is independent of the generating medium. This interferometer can be a useful tool for measuring the relative phase shift between any two gas species and for studying ultrafast dynamics of their electronic and nuclear motion.

Parallel Wavefront Analysis for a 4D Interferometer

Science.gov (United States)

Rao, Shanti R.

2011-01-01

This software provides a programming interface for automating data collection with a PhaseCam interferometer from 4D Technology, and distributing the image-processing algorithm across a cluster of general-purpose computers. Multiple instances of 4Sight (4D Technology s proprietary software) run on a networked cluster of computers. Each connects to a single server (the controller) and waits for instructions. The controller directs the interferometer to several images, then assigns each image to a different computer for processing. When the image processing is finished, the server directs one of the computers to collate and combine the processed images, saving the resulting measurement in a file on a disk. The available software captures approximately 100 images and analyzes them immediately. This software separates the capture and analysis processes, so that analysis can be done at a different time and faster by running the algorithm in parallel across several processors. The PhaseCam family of interferometers can measure an optical system in milliseconds, but it takes many seconds to process the data so that it is usable. In characterizing an adaptive optics system, like the next generation of astronomical observatories, thousands of measurements are required, and the processing time quickly becomes excessive. A programming interface distributes data processing for a PhaseCam interferometer across a Windows computing cluster. A scriptable controller program coordinates data acquisition from the interferometer, storage on networked hard disks, and parallel processing. Idle time of the interferometer is minimized. This architecture is implemented in Python and JavaScript, and may be altered to fit a customer s needs.

Comparison of the performance of the next generation of optical interferometers

Science.gov (United States)

Pisani, Marco; Yacoot, Andrew; Balling, Petr; Bancone, Nicola; Birlikseven, Cengiz; Çelik, Mehmet; Flügge, Jens; Hamid, Ramiz; Köchert, Paul; Kren, Petr; Kuetgens, Ulrich; Lassila, Antti; Bartolo Picotto, Gian; Şahin, Ersoy; Seppä, Jeremias; Tedaldi, Matthew; Weichert, Christoph

2012-08-01

Six European National Measurement Institutes (NMIs) have joined forces within the European Metrology Research Programme funded project NANOTRACE to develop the next generation of optical interferometers having a target uncertainty of 10 pm. These are needed for NMIs to provide improved traceable dimensional metrology that can be disseminated to the wider nanotechnology community, thereby supporting the growth in nanotechnology. Several approaches were followed in order to develop the interferometers. This paper briefly describes the different interferometers developed by the various partners and presents the results of a comparison of performance of the optical interferometers using an x-ray interferometer to generate traceable reference displacements.

Development of holographic interferometer for non-destructive testing

International Nuclear Information System (INIS)

Kim, Cheol Jung; Baik, Sung Hoon; Shin, Jang Soo; Cho, Jai Wan; Kim, Duk Hyeon; Hong, Suck Kyoung; Lee, Sang Kil; Kim, Heon Jun; Park, Chang Jin

1993-02-01

This project sets the goal at development of holographic interferometer. In this interferometer, fringe localization and imaging of object are considered. And collimated beam and wedge are used for the high-speed recording and formation of carrier fringes, respectively. With this real-time holographic interferometer, not only experiments were conducted on natural convection and flame jet, but also on high speed flow phenomena such as shock wave propagation. Visualization of high-speed flow is recorded in high-speed camera with framing rate ∼ 35000f/s. And to analyze axis symmetric phase object, analysis program was developed. (Author)

A Michelson interferometer for X-rays and thermal neutrons

International Nuclear Information System (INIS)

Appel, A.

1992-01-01

The introduced interferometer consists of an LLL interferometer and a phase-displacing Bragg groove component. A part of the radiation path between the Lane mirrors in the Bragg grooves is replaced by a radiation path, whose wave number vector has a slightly different direction compared to the Lane case by the refraction correction. If the angles of incidence in the two grooves are different, then a difference in path is produced between the beams producing interference. This is the first X-ray interferometer which works like an optical Michelson interferometer. As there are no basic limits to resolution by absorption or dispersion, for example, it opens up the possibility of carrying out Fourier spectroscopy in the A wavelength range. (orig.) [de

Analysis of a four-mirror-cavity enhanced Michelson interferometer.

Science.gov (United States)

Thüring, André; Lück, Harald; Danzmann, Karsten

2005-12-01

We investigate the shot-noise-limited sensitivity of a four-mirror-cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derived. Although the parameter space has 11 dimensions, a detailed analysis of the resonance feature gives boundary conditions allowing systematic parameter studies.

A heterodyne interferometer with periodic nonlinearities smaller than ±10 pm

International Nuclear Information System (INIS)

Weichert, C; Köchert, P; Köning, R; Flügge, J; Andreas, B; Kuetgens, U; Yacoot, A

2012-01-01

The PTB developed a new optical heterodyne interferometer in the context of the European joint research project ‘Nanotrace’. A new optical concept using plane-parallel plates and spatially separated input beams to minimize the periodic nonlinearities was realized. Furthermore, the interferometer has the resolution of a double-path interferometer, compensates for possible angle variations between the mirrors and the interferometer optics and offers a minimal path difference between the reference and the measurement arm. Additionally, a new heterodyne phase evaluation based on an analogue to digital converter board with embedded field programmable gate arrays was developed, providing a high-resolving capability in the single-digit picometre range. The nonlinearities were characterized by a comparison with an x-ray interferometer, over a measurement range of 2.2 periods of the optical interferometer. Assuming an error-free x-ray interferometer, the nonlinearities are considered to be the deviation of the measured displacement from a best-fit line. For the proposed interferometer, nonlinearities smaller than ±10 pm were observed without any quadrature fringe correction. (paper)

A heterodyne interferometer with periodic nonlinearities smaller than ±10 pm

Science.gov (United States)

Weichert, C.; Köchert, P.; Köning, R.; Flügge, J.; Andreas, B.; Kuetgens, U.; Yacoot, A.

2012-09-01

The PTB developed a new optical heterodyne interferometer in the context of the European joint research project ‘Nanotrace’. A new optical concept using plane-parallel plates and spatially separated input beams to minimize the periodic nonlinearities was realized. Furthermore, the interferometer has the resolution of a double-path interferometer, compensates for possible angle variations between the mirrors and the interferometer optics and offers a minimal path difference between the reference and the measurement arm. Additionally, a new heterodyne phase evaluation based on an analogue to digital converter board with embedded field programmable gate arrays was developed, providing a high-resolving capability in the single-digit picometre range. The nonlinearities were characterized by a comparison with an x-ray interferometer, over a measurement range of 2.2 periods of the optical interferometer. Assuming an error-free x-ray interferometer, the nonlinearities are considered to be the deviation of the measured displacement from a best-fit line. For the proposed interferometer, nonlinearities smaller than ±10 pm were observed without any quadrature fringe correction.

A Climatology of Tropospheric CO over the Central and Southeastern United States and the Southwestern Pacific Ocean Derived from Space, Air, and Ground-based Infrared Interferometer Spectra

Science.gov (United States)

McMillian, W. Wallace; Strow, L. Larrabee; Revercomb, H.; Knuteson, R.; Thompson, A.

2003-01-01

This final report summarizes all research activities and publications undertaken as part of NASA Atmospheric Chemistry and Modeling Analysis Program (ACMAP) Grant NAG-1-2022, 'A Climatology of Tropospheric CO over the Central and Southeastern United States and the Southwestern Pacific Ocean Derived from Space, Air, and Ground-based Infrared Interferometer Spectra'. Major project accomplishments include: (1) analysis of more than 300,000 AERI spectra from the ARM SGP site yielding a 5-year (1998-2002) timeseries of CO retrievals from the Lamont, OK AERI; (2) development of a prototype CO profile retrieval algorithm for AERI spectra; (3) validation and publication of the first CO retrievals from the Scanning High-resolution Interferometer Sounder (SHIS); and (4) development of a prototype AERI tropospheric O3 retrieval algorithm. Compilation and publication of the 5-year Lamont, OK timeseries is underway including a new collaboration with scientists at the Lawrence Berkeley National Laboratory. Public access to this data will be provided upon article submission. A comprehensive CO analysis of the archive of HIS spectra of remains as the only originally proposed activity with little progress. The greatest challenge faced in this project was motivating the University of Wisconsin Co-Investigators to deliver their archived HIS and AERIOO data along with the requisite temperature and water vapor profiles in a timely manner. Part of the supplied HIS dataset from ASHOE may be analyzed as part of a Master s Thesis under a separate project. Our success with the SAFARI 2000 SHIS CO analysis demonstrates the utility of such aircraft remote sensing data given the proper support from the instrument investigators. In addition to the PI and Co-I s, personnel involved in this CO climatology project include one Post Doctoral Fellow, one Research Scientist, two graduate students, and two undergraduate students. A total of fifteen presentations regarding research related to this

Quantum Spin Transport in Mesoscopic Interferometer

Directory of Open Access Journals (Sweden)

Zein W. A.

2007-10-01

Full Text Available Spin-dependent conductance of ballistic mesoscopic interferometer is investigated. The quantum interferometer is in the form of ring, in which a quantum dot is embedded in one arm. This quantum dot is connected to one lead via tunnel barrier. Both Aharonov- Casher and Aharonov-Bohm e ects are studied. Our results confirm the interplay of spin-orbit coupling and quantum interference e ects in such confined quantum systems. This investigation is valuable for spintronics application, for example, quantum information processing.

Analysis, Modeling, and Simulation (AMS) Testbed Development and Evaluation to Support Dynamic Mobility Applications (DMA) and Active Transportation and Demand Management (ATDM) Programs - calibration Report for Phoenix Testbed : Final Report. [supporting datasets - Phoenix Testbed

Science.gov (United States)

2017-07-26

The datasets in this zip file are in support of FHWA-JPO-16-379, Analysis, Modeling, and Simulation (AMS) Testbed Development and Evaluation to Support Dynamic Mobility Applications (DMA) and Active Transportation and Demand Management (ATDM) Program...

Talbot Carpet Simulation for X-ray grating interferometer

Energy Technology Data Exchange (ETDEWEB)

Kim, Youngju; Oh, Ohsung; Jeong, Hanseong; Kim, Jeongho; Lee, Seung Wook [Pusan National University, Busan (Korea, Republic of); Kim, Jongyul; Moon, Myungkook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

In this study, Talbot carpet simulator has been developed to visualize the X-ray grating interference patterns in grating interferometer. We have simulated X-ray interference for a variety of simulations and demonstrated a few examples in this summary. Grating interferometer produces interference of X-ray called Talbot pattern with gratings manufactured in micro scale. Talbot pattern is self-images of phase grating which develops interference as beam splitter that is one of gratings consisted of interferometer. As the other gratings, there are source grating makes coherence and analyze grating is used to analyze interference onto detector. Talbot carpet has been studied as the beam behavior which is distinguished with common X-ray imaging systems. It is helpful to understand grating interferometer and possible to expect beams' oscillation for designing theoretically. We confirm pattern has periodicity produced by interference after pi and pi/2 phase grating and changes in the perpendicular direction to entrance face according to phase objects.

Combining Passive Microwave Sounders with CYGNSS information for improved retrievals: Observations during Hurricane Harvey

Science.gov (United States)

Schreier, M. M.

2017-12-01

The launch of CYGNSS (Cyclone Global Navigation Satellite System) has added an interesting component to satellite observations: it can provide wind speeds in the tropical area with a high repetition rate. Passive microwave sounders that are overpassing the same region can benefit from this information, when it comes to the retrieval of temperature or water profiles: the uncertainty about wind speeds has a strong impact on emissivity and reflectivity calculations with respect to surface temperature. This has strong influences on the uncertainty of retrieval of temperature and water content, especially under extreme weather conditions. Adding CYGNSS information to the retrieval can help to reduce errors and provide a significantly better sounder retrieval. Based on observations during Hurricane Harvey, we want to show the impact of CYGNSS data on the retrieval of passive microwave sensors. We will show examples on the impact on the retrieval from polar orbiting instruments, like the Advanced Technology Microwave Sounder (ATMS) and AMSU-A/B on NOAA-18 and 19. In addition we will also show the impact on retrievals from HAMSR (High Altitude MMIC Sounding Radiometer), which was flying on the Global Hawk during the EPOCH campaign. We will compare the results with other observations and estimate the impact of additional CYGNSS information on the microwave retrieval, especially on the impact in error and uncertainty reduction. We think, that a synergetic use of these different data sources could significantly help to produce better assimilation products for forecast assimilation.

Very small beam-size measurement by a reflective synchrotron radiation interferometer

Directory of Open Access Journals (Sweden)

T. Naito

2006-12-01

Full Text Available A synchrotron radiation (SR interferometer with Herschelian reflective optics has been developed for the measurement of beams of several μm in size. In a conventional refractive SR interferometer, the dispersion effect of the objective lens limits the instrument to a smaller range of beam-size measurements. To avoid this problem, we designed a Herschelian arrangement of reflective optics for the interferometer. The effectiveness of the reflective SR interferometer was confirmed at the KEK Accelerator Test Facility (ATF damping ring. The measured vertical beam size obtained using the reflective SR interferometer was 4.7   μm and the estimated vertical emittance was 0.97×10^{-11}   m.

Quantum contextuality in neutron interferometer experiments

International Nuclear Information System (INIS)

Hasegawa, Yuji; Loidl, Rudolf; Baron, Matthias; Badurek, Gerald; Rauch, Helmut

2006-01-01

Non-local correlations between sufficiently separated subsystems have been extensively discussed. Such a non-locality can be interpreted as a consequence of the correlation between commuting observables. A more general concept, i.e., contextuality, compared to non-locality can be introduced to describe striking phenomena predicted by quantum theory. As the first example, we report a neutron interferometer experiment, where the spin and the path degrees of freedom are used to exhibit the clear violation of a Bell-like inequality. Other aspects of the quantum contextuality is presented, e.g., a flavor of Kochen-Specker-like contradiction in neutron optical experiments, in addition to the quantum state tomography of the Bell-states which are used in the experiments

Prognostics-Enabled Power Supply for ADAPT Testbed, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Ridgetop's role is to develop electronic prognostics for sensing power systems in support of NASA/Ames ADAPT testbed. The prognostic enabled power systems from...

Space Plasma Slab Studies using a new 3D Embedded Reconfigurable MPSoC Sounder

Science.gov (United States)

Dekoulis, George

2016-07-01

This paper presents recent ionospheric slab thickness measurements using a new mobile digital sounder system. The datasets obtained have been compared to the results of existing sounders in operation. The data validity has been verified. The slab thickness data allow constant monitoring of the lower ionosphere revealing the dynamic trends of the physical processes being involved. The prototype offers a tremendous amount of hardware processing power and a previously unseen response time in servicing the input and output data interfaces. This has been enabled by incorporating the latest three-dimensional Ultrascale+ technologies available commercially from the reconfigurable Field Programmable Gate Array (FPGA) computing industry. Furthermore, a previously developed Network-on-Chip (NoC) design methodology has been incorporated for connecting and controlling the application driven multiprocessor network. The system determines electron distributions, aggregate electromagnetic field gradients and plasma current density.

Towards a Perpetual Sensor Network Testbed without Backchannel

DEFF Research Database (Denmark)

Johansen, Aslak; Bonnet, Philippe; Sørensen, Thomas

2012-01-01

The sensor network testbeds available today rely on a communication channel different from the mote radio - a backchannel - to facilitate mote reprogramming, health monitoring and performance analysis. Such backchannels are either supported as wired communication channels (USB or Ethernet), or vi...

Data dissemination in the wild: A testbed for high-mobility MANETs

DEFF Research Database (Denmark)

Vingelmann, Peter; Pedersen, Morten Videbæk; Heide, Janus

2012-01-01

This paper investigates the problem of efficient data dissemination in Mobile Ad hoc NETworks (MANETs) with high mobility. A testbed is presented; which provides a high degree of mobility in experiments. The testbed consists of 10 autonomous robots with mobile phones mounted on them. The mobile...... information, and the goal is to convey that information to all devices. A strategy is proposed that uses UDP broadcast transmissions and random linear network coding to facilitate the efficient exchange of information in the network. An application is introduced that implements this strategy on Nokia phones...

Local readout enhancement for detuned signal-recycling interferometers

International Nuclear Information System (INIS)

Rehbein, Henning; Mueller-Ebhardt, Helge; Schnabel, Roman; Danzmann, Karsten; Somiya, Kentaro; Chen Yanbei; Li Chao

2007-01-01

High power detuned signal-recycling interferometers currently planned for second-generation interferometric gravitational-wave detectors (for example Advanced LIGO) are characterized by two resonances in the detection band, an optical resonance and an optomechanical resonance which is upshifted from the suspension pendulum frequency due to the so-called optical-spring effect. The detector's sensitivity is enhanced around these two resonances. However, at frequencies below the optomechanical resonance frequency, the sensitivity of such interferometers is significantly lower than non-optical-spring configurations with comparable circulating power; such a drawback can also compromise high-frequency sensitivity, when an optimization is performed on the overall sensitivity of the interferometer to a class of sources. In this paper, we clarify the reason for such a low sensitivity, and propose a way to fix this problem. Motivated by the optical-bar scheme of Braginsky, Gorodetsky, and Khalili, we propose to add a local readout scheme which measures the motion of the arm-cavity front mirror, which at low frequencies moves together with the arm-cavity end mirror, under the influence of gravitational waves. This scheme improves the low-frequency quantum-noise-limited sensitivity of optical-spring interferometers significantly and can be considered as an incorporation of the optical-bar scheme into currently planned second-generation interferometers. On the other hand it can be regarded as an extension of the optical-bar scheme. Taking compact binary inspiral signals as an example, we illustrate how this scheme can be used to improve the sensitivity of the planned Advanced LIGO interferometer, in various scenarios, using a realistic classical-noise budget. We also discuss how this scheme can be implemented in Advanced LIGO with relative ease

Non magnetic neutron spin quantum precession using multilayer spin splitter and a phase-spin echo interferometer

Energy Technology Data Exchange (ETDEWEB)

Ebisawa, T.; Tasaki, S.; Kawai, T.; Akiyoshi, T. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Achiwa, N.; Hino, M.; Otake, Y.; Funahashi, H.

1996-08-01

The authors have developed cold neutron optics and interferometry using multilayer mirrors. The advantages of the multilayer mirrors are their applicability to long wavelength neutrons and a great variety of the mirror performance. The idea of the present spin interferometry is based on nonmagnetic neutron spin quantum precession using multilayer spin splitters. The equation for polarized neutrons means that the polarized neutrons are equivalent to the coherent superposition of two parallel spin eigenstates. The structure and principle of a multilayer spin splitter are explained, and the nonmagnetic gap layer of the multilayer spin splitter gives rise to neutron spin quantum precession. The performance test of the multilayer spin splitter were made with a new spin interferometer, which is analogous optically to a spin echo system with vertical precession field. The spin interferometers were installed at Kyoto University research reactor and the JRR-3. The testing method and the results are reported. The performance tests on a new phase-spin echo interferometer are described, and its applications to the development of a high resolution spin echo system and a Jamin type cold neutron interferometer are proposed. (K.I.)

CO laser interferometer for REB-plasma experiments

International Nuclear Information System (INIS)

Burmasov, V.S.; Kruglyakov, E.P.

1996-01-01

The Michelson carbon oxide laser interferometer for measuring plasma density in studies on REB-plasma interaction is described. A detail description of the interferometer and CO laser is presented. For a selection of a single wavelength laser operation the CaF 2 prism is applied. A Ge:Au photoconductor at 77 deg K is applied as the detector. The CO laser radiation at λ 5.34 μm coincides with the detector maximum sensitivity (of the order of 1000 V/W). This increases the interferometer sensitivity about ten times with respect to the He-Ne laser (λ = 3.39 μm) used as the source of light. The typical interferogram and time evolution of plasma density obtained at GOL-M device are presented. (author). 3 figs., 5 refs

CO laser interferometer for REB-plasma experiments

Energy Technology Data Exchange (ETDEWEB)

Burmasov, V S; Kruglyakov, E P [Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation)

1997-12-31

The Michelson carbon oxide laser interferometer for measuring plasma density in studies on REB-plasma interaction is described. A detail description of the interferometer and CO laser is presented. For a selection of a single wavelength laser operation the CaF{sub 2} prism is applied. A Ge:Au photoconductor at 77 deg K is applied as the detector. The CO laser radiation at {lambda} 5.34 {mu}m coincides with the detector maximum sensitivity (of the order of 1000 V/W). This increases the interferometer sensitivity about ten times with respect to the He-Ne laser ({lambda} = 3.39 {mu}m) used as the source of light. The typical interferogram and time evolution of plasma density obtained at GOL-M device are presented. (author). 3 figs., 5 refs.

Broadband infrared beam splitter for spaceborne interferometric infrared sounder.

Science.gov (United States)

Yu, Tianyan; Liu, Dingquan; Qin, Yang

2014-10-01

A broadband infrared beam splitter (BS) on ZnSe substrate used for the spaceborne interferometric infrared sounder (SIIRS) is studied in the spectral range of 4.44-15 μm. Both broadband antireflection coating and broadband beam-splitter coating in this BS are designed and tested. To optimize the optical properties and the stability of the BS, suitable infrared materials were selected, and improved deposition techniques were applied. The designed structures matched experimental data well, and the properties of the BS met the application specification of SIIRS.

Open-Source Based Testbed for Multioperator 4G/5G Infrastructure Sharing in Virtual Environments

Directory of Open Access Journals (Sweden)

Ricardo Marco Alaez

2017-01-01

Full Text Available Fourth-Generation (4G mobile networks are based on Long-Term Evolution (LTE technologies and are being deployed worldwide, while research on further evolution towards the Fifth Generation (5G has been recently initiated. 5G will be featured with advanced network infrastructure sharing capabilities among different operators. Therefore, an open-source implementation of 4G/5G networks with this capability is crucial to enable early research in this area. The main contribution of this paper is the design and implementation of such a 4G/5G open-source testbed to investigate multioperator infrastructure sharing capabilities executed in virtual architectures. The proposed design and implementation enable the virtualization and sharing of some of the components of the LTE architecture. A testbed has been implemented and validated with intensive empirical experiments conducted to validate the suitability of virtualizing LTE components in virtual infrastructures (i.e., infrastructures with multitenancy sharing capabilities. The impact of the proposed technologies can lead to significant saving of both capital and operational costs for mobile telecommunication operators.

Michelson and His Interferometer

Science.gov (United States)

Shankland, Robert S.

1974-01-01

Presents a brief historical account of Michelson's invention of his interferometer with some subsequent ingenious applications of its capabilities for precise measurement discussed in details, including the experiment on detrmination of the diameters for heavenly bodies. (CC)

A combined scanning tunnelling microscope and x-ray interferometer

Science.gov (United States)

Yacoot, Andrew; Kuetgens, Ulrich; Koenders, Ludger; Weimann, Thomas

2001-10-01

A monolithic x-ray interferometer made from silicon and a scanning tunnelling microscope have been combined and used to calibrate grating structures with periodicities of 100 nm or less. The x-ray interferometer is used as a translation stage which moves in discrete steps of 0.192 nm, the lattice spacing of the silicon (220) planes. Hence, movements are traceable to the definition of the metre and the nonlinearity associated with the optical interferometers used to measure displacement in more conventional metrological scanning probe microscopes (MSPMs) removed.

Polar cap mesosphere wind observations: comparisons of simultaneous measurements with a Fabry-Perot interferometer and a field-widened Michelson interferometer.

Science.gov (United States)

Fisher, G M; Killeen, T L; Wu, Q; Reeves, J M; Hays, P B; Gault, W A; Brown, S; Shepherd, G G

2000-08-20

Polar cap mesospheric winds observed with a Fabry-Perot interferometer with a circle-to-line interferometer optical (FPI/CLIO) system have been compared with measurements from a field-widened Michelson interferometer optimized for E-region winds (ERWIN). Both instruments observed the Meinel OH emission emanating from the mesopause region (approximately 86 km) at Resolute Bay, Canada (74.9 degrees N, 94.9 degrees W). This is the first time, to our knowledge, that winds measured simultaneously from a ground-based Fabry-Perot interferometer and a ground-based Michelson interferometer have been compared at the same location. The FPI/CLIO and ERWIN instruments both have a capability for high temporal resolution (less than 10 min for a full scan in the four cardinal directions and the zenith). Statistical comparisons of hourly mean winds for both instruments by scatterplots show excellent agreement, indicating that the two optical techniques provide equivalent observations of mesopause winds. Small deviations in the measured wind can be ascribed to the different zenith angles used by the two instruments. The combined measurements illustrate the dominance of the 12-h wave in the mesopause winds at Resolute Bay, with additional evidence for strong gravity wave activity with much shorter periods (tens of minutes). Future operations of the two instruments will focus on observation of complementary emissions, providing a unique passive optical capability for the determination of neutral winds in the geomagnetic polar cap at various altitudes near the mesopause.

Nonlinear Michelson interferometer for improved quantum metrology

OpenAIRE

Luis, Alfredo; Rivas, Ángel

2015-01-01

We examine quantum detection via a Michelson interferometer embedded in a gas with Kerr nonlinearity. This nonlinear interferometer is illuminated by pulses of classical light. This strategy combines the robustness against practical imperfections of classical light with the improvement provided by nonlinear processes. Regarding ultimate quantum limits, we stress that, as a difference with linear schemes, the nonlinearity introduces pulse duration as a new variable into play along with the ene...

A study of microwave interferometers for electron density measurements in REB-plasma experiments

International Nuclear Information System (INIS)

Saxena, A.C.; Paithankar, A.S.; Iyyengar, S.K.; Rohatgi, V.K.

1981-01-01

In order to select a suitable microwave interferometer for electron density measurements in Relativistic Electron Beam (REB)-Plasma Experiments, a study has been carried out of four types of interferometers, viz. simple interferometer, standing-wave interferometer, frequency and phase modulated interferometers. Various direct reading interferometers which give a voltage proportional to the phase shift, are also discussed. Systems have been analysed in terms of time resolution, phase sensitivity, system stability, ease of measurement etc. Theoretical and experimental limitations of various systems have been indicated. Summary of the various systems is presented in a table to aid the experimentalist to select the most appropriate system for the prevailina experimental conditions. Finally, an attempt has been made to find out the interferometer system best suited for REB-Plasma Experiments. (author)

Variability at Multiple Scales: Using an Array of Current- and Pressure-Sensor Equipped Inverted Echo Sounders to Measure the Ocean

Science.gov (United States)

2016-11-29

of Current- and Pressure - Sensor Equipped Inverted Echo Sounders to Measure the Ocean 5b. GRANT NUMBER NOOO 14-15-1-2857 5c. PROGRAM ELEMENT NUMBER...inverted echo sounders (lESs) equipped with pressure and current sensors (CPIESs). CPIESs are moored instruments that measure the round-trip acoustic...at a range of spatial and temporal scales. The goals of this project were to enhance the pool of pressure - sensor equipped lESs available at the

Variability at Multiple Scales: Using an Array of Current and Pressure Sensor Equipped Inverted Echo Sounders to Measure the Ocean

Science.gov (United States)

2016-11-29

of Current- and Pressure - Sensor Equipped Inverted Echo Sounders to Measure the Ocean 5b. GRANT NUMBER NOOO 14-15-1-2857 5c. PROGRAM ELEMENT NUMBER...inverted echo sounders (lESs) equipped with pressure and current sensors (CPIESs). CPIESs are moored instruments that measure the round-trip acoustic...at a range of spatial and temporal scales. The goals of this project were to enhance the pool of pressure - sensor equipped lESs available at the

Performance evaluation of a thermal Doppler Michelson interferometer system.

Science.gov (United States)

Mani, Reza; Dobbie, Steven; Scott, Alan; Shepherd, Gordon; Gault, William; Brown, Stephen

2005-11-20

The thermal Doppler Michelson interferometer is the primary element of a proposed limb-viewing satellite instrument called SWIFT (Stratospheric Wind Interferometer for Transport studies). SWIFT is intended to measure stratospheric wind velocities in the altitude range of 15-45 km. SWIFT also uses narrowband tandem etalon filters made of germanium to select a line out of the thermal spectrum. The instrument uses the same technique of phase-stepping interferometry employed by the Wind Imaging Interferometer onboard the Upper Atmosphere Research Satellite. A thermal emission line of ozone near 9 microm is used to detect the Doppler shift due to winds. A test bed was set up for this instrument that included the Michelson interferometer and the etalon filters. For the test bed work, we investigate the behavior of individual components and their combination and report the results.

Development of a suspended-mass RSE interferometer using third harmonic demodulation

CERN Document Server

Miyakawa, O; Heinzel, G; Kawamura, S

2002-01-01

The most important point of a resonant sideband extraction (RSE) experiment is the signal extraction for control of the interferometer. We proposed a new signal-sensing method for the single modulation scheme. This method uses the third harmonic demodulation (THD) with a particular asymmetry in the interferometer which makes the third-order sidebands vanish at the detecting port. We have successfully locked a suspended-mass RSE interferometer for the first time by the THD method. The transfer function of the interferometer was measured to confirm the RSE effect.

Development of a suspended-mass RSE interferometer using third harmonic demodulation

International Nuclear Information System (INIS)

Miyakawa, Osamu; Somiya, Kentaro; Heinzel, Gerhard; Kawamura, Seiji

2002-01-01

The most important point of a resonant sideband extraction (RSE) experiment is the signal extraction for control of the interferometer. We proposed a new signal-sensing method for the single modulation scheme. This method uses the third harmonic demodulation (THD) with a particular asymmetry in the interferometer which makes the third-order sidebands vanish at the detecting port. We have successfully locked a suspended-mass RSE interferometer for the first time by the THD method. The transfer function of the interferometer was measured to confirm the RSE effect

Automatic Integration Testbeds validation on Open Science Grid

International Nuclear Information System (INIS)

Caballero, J; Potekhin, M; Thapa, S; Gardner, R

2011-01-01

A recurring challenge in deploying high quality production middleware is the extent to which realistic testing occurs before release of the software into the production environment. We describe here an automated system for validating releases of the Open Science Grid software stack that leverages the (pilot-based) PanDA job management system developed and used by the ATLAS experiment. The system was motivated by a desire to subject the OSG Integration Testbed to more realistic validation tests. In particular those which resemble to every extent possible actual job workflows used by the experiments thus utilizing job scheduling at the compute element (CE), use of the worker node execution environment, transfer of data to/from the local storage element (SE), etc. The context is that candidate releases of OSG compute and storage elements can be tested by injecting large numbers of synthetic jobs varying in complexity and coverage of services tested. The native capabilities of the PanDA system can thus be used to define jobs, monitor their execution, and archive the resulting run statistics including success and failure modes. A repository of generic workflows and job types to measure various metrics of interest has been created. A command-line toolset has been developed so that testbed managers can quickly submit 'VO-like' jobs into the system when newly deployed services are ready for testing. A system for automatic submission has been crafted to send jobs to integration testbed sites, collecting the results in a central service and generating regular reports for performance and reliability.

Automatic Integration Testbeds validation on Open Science Grid

Science.gov (United States)

Caballero, J.; Thapa, S.; Gardner, R.; Potekhin, M.

2011-12-01

A recurring challenge in deploying high quality production middleware is the extent to which realistic testing occurs before release of the software into the production environment. We describe here an automated system for validating releases of the Open Science Grid software stack that leverages the (pilot-based) PanDA job management system developed and used by the ATLAS experiment. The system was motivated by a desire to subject the OSG Integration Testbed to more realistic validation tests. In particular those which resemble to every extent possible actual job workflows used by the experiments thus utilizing job scheduling at the compute element (CE), use of the worker node execution environment, transfer of data to/from the local storage element (SE), etc. The context is that candidate releases of OSG compute and storage elements can be tested by injecting large numbers of synthetic jobs varying in complexity and coverage of services tested. The native capabilities of the PanDA system can thus be used to define jobs, monitor their execution, and archive the resulting run statistics including success and failure modes. A repository of generic workflows and job types to measure various metrics of interest has been created. A command-line toolset has been developed so that testbed managers can quickly submit "VO-like" jobs into the system when newly deployed services are ready for testing. A system for automatic submission has been crafted to send jobs to integration testbed sites, collecting the results in a central service and generating regular reports for performance and reliability.

Optical diameters of stars measured with the Mt. Wilson Mark III interferometer

International Nuclear Information System (INIS)

Simon, R.S.; Mozurkewich, D.; Johnston, K.J.; Gaume, R.; Hutter, D.J.; Bowers, P.F.; Colavita, M.M.; Shao, M.

1990-01-01

Reliable stellar angular diameters can now be determined using the Mark III Optical Interferometer located on Mt. Wilson, California. The Mark III is a Michelson Interferometer capable of measuring the interferometric fringe visibility for stars using interferometer baselines varying from 3 to 31.5 meters in length. Angular diameters measured with the Mark III Optical Interferometer are presented for 12 stars at wavelengths of 450 and 800 nm. 10 refs

Naval Prototype Optical Interferometer (NPOI)

Data.gov (United States)

Federal Laboratory Consortium — FUNCTION: Used for astrometry and astronomical imaging, the Naval Prototype Optical Interferometer (NPOI) is a distributed aperture optical telescope. It is operated...

Implementation of a RPS Cyber Security Test-bed with Two PLCs

International Nuclear Information System (INIS)

Shin, Jinsoo; Heo, Gyunyoung; Son, Hanseong; An, Yongkyu; Rizwan, Uddin

2015-01-01

Our research team proposed the methodology to evaluate cyber security with Bayesian network (BN) as a cyber security evaluation model and help operator, licensee, licensor or regulator in granting evaluation priorities. The methodology allowed for overall evaluation of cyber security by considering architectural aspect of facility and management aspect of cyber security at the same time. In order to emphasize reality of this model by inserting true data, it is necessary to conduct a penetration test that pretends an actual cyber-attack. Through the collaboration with University of Illinois at Urbana-Champaign, which possesses the Tricon a safety programmable logic controller (PLC) used at nuclear power plants and develops a test-bed for nuclear power plant, a test-bed for reactor protection system (RPS) is being developed with the PLCs. Two PLCs are used to construct a simple test-bed for RPS, bi-stable processor (BP) and coincidence processor (CP). By using two PLCs, it is possible to examine cyber-attack against devices such as PLC, cyber-attack against communication between devices, and the effects of a PLC on the other PLC. Two PLCs were used to construct a test-bed for penetration test in this study. Advantages of using two or more PLCs instead of single PLC are as follows. 1) Results of cyber-attack reflecting characteristics among PLCs can be obtained. 2) Cyber-attack can be attempted using a method of attacking communication between PLCs. True data obtained can be applied to existing cyber security evaluation model to emphasize reality of the model

Implementation of a RPS Cyber Security Test-bed with Two PLCs

Energy Technology Data Exchange (ETDEWEB)

Shin, Jinsoo; Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Son, Hanseong [Joongbu Univ., Geumsan (Korea, Republic of); An, Yongkyu; Rizwan, Uddin [University of Illinois at Urbana-Champaign, Urbana (United States)

2015-10-15

Our research team proposed the methodology to evaluate cyber security with Bayesian network (BN) as a cyber security evaluation model and help operator, licensee, licensor or regulator in granting evaluation priorities. The methodology allowed for overall evaluation of cyber security by considering architectural aspect of facility and management aspect of cyber security at the same time. In order to emphasize reality of this model by inserting true data, it is necessary to conduct a penetration test that pretends an actual cyber-attack. Through the collaboration with University of Illinois at Urbana-Champaign, which possesses the Tricon a safety programmable logic controller (PLC) used at nuclear power plants and develops a test-bed for nuclear power plant, a test-bed for reactor protection system (RPS) is being developed with the PLCs. Two PLCs are used to construct a simple test-bed for RPS, bi-stable processor (BP) and coincidence processor (CP). By using two PLCs, it is possible to examine cyber-attack against devices such as PLC, cyber-attack against communication between devices, and the effects of a PLC on the other PLC. Two PLCs were used to construct a test-bed for penetration test in this study. Advantages of using two or more PLCs instead of single PLC are as follows. 1) Results of cyber-attack reflecting characteristics among PLCs can be obtained. 2) Cyber-attack can be attempted using a method of attacking communication between PLCs. True data obtained can be applied to existing cyber security evaluation model to emphasize reality of the model.

Phase-Shifting Liquid Crystal Interferometers for Microgravity Fluid Physics

Science.gov (United States)

Griffin, DeVon W.; Marshall, Keneth L.

2002-01-01

The initial focus of this project was to eliminate both of these problems in the Liquid Crystal Point-Diffraction Interferometer (LCPDI). Progress toward that goal will be described, along with the demonstration of a phase shifting Liquid Crystal Shearing Interferometer (LCSI) that was developed as part of this work. The latest LCPDI, other than a lens to focus the light from a test section onto a diffracting microsphere within the interferometer and a collimated laser for illumination, the pink region contained within the glass plates on the rod-mounted platform is the complete interferometer. The total width is approximately 1.5 inches with 0.25 inches on each side for bonding the electrical leads. It is 1 inch high and there are only four diffracting microspheres within the interferometer. As a result, it is very easy to align, achieving the first goal. The liquid crystal electro-optical response time is a function of layer thickness, with thinner devices switching faster due to a reduction in long-range viscoelastic forces between the LC molecules. The LCPDI has a liquid crystal layer thickness of 10 microns, which is controlled by plastic or glass microspheres embedded in epoxy 'pads' at the corners of the device. The diffracting spheres are composed of polystyrene/divinyl benzene polymer with an initial diameter of 15 microns. The spheres deform slightly when the interferometer is assembled to conform to the spacing produced by the microsphere-filled epoxy spacer pads. While the speed of this interferometer has not yet been tested, previous LCPDIs fabricated at the Laboratory for Laser Energetics switched at a rate of approximately 3.3 Hz, a factor of 10 slower than desired. We anticipate better performance when the speed of these interferometers is tested since they are approximately three times thinner. Phase shifting in these devices is a function of the AC voltage level applied to the liquid crystal. As the voltage increases, the dye in the liquid crystal

Variable Coding and Modulation Experiment Using NASA's Space Communication and Navigation Testbed

Science.gov (United States)

Downey, Joseph A.; Mortensen, Dale J.; Evans, Michael A.; Tollis, Nicholas S.

2016-01-01

National Aeronautics and Space Administration (NASA)'s Space Communication and Navigation Testbed on the International Space Station provides a unique opportunity to evaluate advanced communication techniques in an operational system. The experimental nature of the Testbed allows for rapid demonstrations while using flight hardware in a deployed system within NASA's networks. One example is variable coding and modulation, which is a method to increase data-throughput in a communication link. This paper describes recent flight testing with variable coding and modulation over S-band using a direct-to-earth link between the SCaN Testbed and the Glenn Research Center. The testing leverages the established Digital Video Broadcasting Second Generation (DVB-S2) standard to provide various modulation and coding options. The experiment was conducted in a challenging environment due to the multipath and shadowing caused by the International Space Station structure. Performance of the variable coding and modulation system is evaluated and compared to the capacity of the link, as well as standard NASA waveforms.

Dispersion interferometer for controlled fusion devices

International Nuclear Information System (INIS)

Drachev, V.P.; Krasnikov, Yu.I.; Bagryansky, P.A.

1992-01-01

A common feature in interferometry is the presence of two independent optical channels. Since wave phase in a medium depends on the geometrical path, polarization and radiation frequency, respectively, one can distinguish three types of interferometric schemes when the channels are geometrically separated, or separation occurs in polarizations or radiation frequencies. We have developed a measurement scheme based on a dispersion interferometer (DI) for plasma diagnostics in the experiments on controlled fusion. DI optical channels have the same geometrical path and are separated in radiation frequency. Use of a common optical path causes the main advantage of the DI technique - low sensitivity to vibrations of optical elements. The use of the DI technique for diagnostics of a laser spark in air and of arc discharges has shown its essential advantages as compared to classical interferometers. Interest in the DI technique from the viewpoint of its application in controlled fusion devices is determined also generated by the possibility of developing a compact multichannel interferometer not requiring a vibration isolation structure. (author) 14 refs., 3 figs

A Battery Certification Testbed for Small Satellite Missions

Science.gov (United States)

Cameron, Zachary; Kulkarni, Chetan S.; Luna, Ali Guarneros; Goebel, Kai; Poll, Scott

2015-01-01

A battery pack consisting of standard cylindrical 18650 lithium-ion cells has been chosen for small satellite missions based on previous flight heritage and compliance with NASA battery safety requirements. However, for batteries that transit through the International Space Station (ISS), additional certification tests are required for individual cells as well as the battery packs. In this manuscript, we discuss the development of generalized testbeds for testing and certifying different types of batteries critical to small satellite missions. Test procedures developed and executed for this certification effort include: a detailed physical inspection before and after experiments; electrical cycling characterization at the cell and pack levels; battery-pack overcharge, over-discharge, external short testing; battery-pack vacuum leak and vibration testing. The overall goals of these certification procedures are to conform to requirements set forth by the agency and identify unique safety hazards. The testbeds, procedures, and experimental results are discussed for batteries chosen for small satellite missions to be launched from the ISS.

Multi-level infrastructure of interconnected testbeds of large-scale wireless sensor networks (MI2T-WSN)

CSIR Research Space (South Africa)

Abu-Mahfouz, Adnan M

2012-06-01

Full Text Available are still required for further testing before the real implementation. In this paper we propose a multi-level infrastructure of interconnected testbeds of large- scale WSNs. This testbed consists of 1000 sensor motes that will be distributed into four...

The Airborne Optical Systems Testbed (AOSTB)

Science.gov (United States)

2017-05-31

are the Atlantic Ocean and coastal waterways, which reflect back very little light at our SWIR operating wavelength of 1064 nm. The Airborne Optical...demonstrate our typical FOPEN capabilities, figure 5 shows two images taken over a forested area near Burlington, VT. Figure 5(a) is a 3D point...Systems Testbed (AOSTB) 1 - 6 STO-MP-SET-999 (a) (b) Fig. 5. Ladar target scan of a forested area in northern Vermont

Spin filtering in a Rashba–Dresselhaus–Aharonov–Bohm double-dot interferometer

International Nuclear Information System (INIS)

Matityahu, Shlomi; Aharony, Amnon; Entin-Wohlman, Ora; Tarucha, Seigo

2013-01-01

We study the spin-dependent transport of spin-1/2 electrons through an interferometer made of two elongated quantum dots or quantum nanowires, which are subject to both an Aharonov–Bohm flux and (Rashba and Dresselhaus) spin–orbit interactions. Similar to the diamond interferometer proposed in our previous papers (Aharony et al 2011 Phys. Rev. B 84 035323; Matityahu et al 2013 Phys. Rev. B 87 205438), we show that the double-dot interferometer can serve as a perfect spin filter due to a spin interference effect. By appropriately tuning the external electric and magnetic fields which determine the Aharonov–Casher and Aharonov–Bohm phases, and with some relations between the various hopping amplitudes and site energies, the interferometer blocks electrons with a specific spin polarization, independent of their energy. The blocked polarization and the polarization of the outgoing electrons is controlled solely by the external electric and magnetic fields and do not depend on the energy of the electrons. Furthermore, the spin filtering conditions become simpler in the linear-response regime, in which the electrons have a fixed energy. Unlike the diamond interferometer, spin filtering in the double-dot interferometer does not require high symmetry between the hopping amplitudes and site energies of the two branches of the interferometer and thus may be more appealing from an experimental point of view. (paper)

Vertical Josephson Interferometer for Tunable Flux Qubit

Energy Technology Data Exchange (ETDEWEB)

Granata, C [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Vettoliere, A [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Lisitskiy, M [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Rombetto, S [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Russo, M [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Ruggiero, B [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Corato, V [Dipartimento di Ingegneria dell' Informazione, Seconda Universita di Napoli, I-8 1031, Aversa (Italy) and Istituto di Cibernetica ' E. Caianiello' del CNR, I-80078, Pozzuoli (Italy); Russo, R [Dipartimento di Ingegneria dell' Informazione, Seconda Universita di Napoli, I-8 1031, Aversa (Italy) and Istituto di Cibernetica ' E. Caianiello' del CNR, I-80078, Pozzuoli (Italy); Silvestrini, P [Dipartimento di Ingegneria dell' Informazione, Seconda Universita di Napoli, I-8 1031, Aversa (Italy) and Istituto di Cibernetica ' E. Caianiello' del CNR, I-80078, Pozzuoli (Italy)

2006-06-01

We present a niobium-based Josephson device as prototype for quantum computation with flux qubits. The most interesting feature of this device is the use of a Josephson vertical interferometer to tune the flux qubit allowing the control of the off-diagonal Hamiltonian terms of the system. In the vertical interferometer, the Josephson current is precisely modulated from a maximum to zero with fine control by a small transversal magnetic field parallel to the rf superconducting loop plane.

EIT Based Gas Detector Design by Using Michelson Interferometer

International Nuclear Information System (INIS)

Abbasian, K.; Rostami, A.; Abdollahi, M. H.

2011-01-01

Electromagnetically induced transparency (EIT) is one of the interesting phenomena of light-matter interaction which modifies matter properties for propagation of light. In other words, we can change the absorption and refractive index (RI) in neighborhood of the resonant frequency using EIT. In this paper, we have doped 3-level quantum dots in one of the Michelson Interferometer's mirror and used EIT to change its RI. So, a controllable phase difference between lights in two arms of interferometer is created. Long response time is the main drawback of Michelson interferometer based sensor, which is resolved by this technique.

FloorNet: Deployment and Evaluation of a Multihop Wireless 802.11 Testbed

Directory of Open Access Journals (Sweden)

Zink Michael

2010-01-01

Full Text Available A lot of attention has been given to multihop wireless networks lately, but further research—in particular, through experimentation—is needed. This attention has motivated an increase in the number of 802.11-based deployments, both indoor and outdoor. These testbeds, which require a significant amount of resources during both deployment and maintenance, are used to run measurements in order to analyze and understand the limitation and differences between analytical or simulation-based figures and the results from real-life experimentation. This paper makes two major contributions: (i first, we describe a novel wireless multihop testbed, which we name FloorNet, that is deployed and operated under the false floor of a lab in our Computer Science building. This false floor provides a strong physical protection that prevents disconnections or misplacements, as well as radio shielding (to some extent thanks to the false floor panels—this later feature is assessed through experimentation; (ii second, by running exhaustive and controlled experiments we are able to analyze the performance limits of commercial off-the-shelf hardware, as well as to derive practical design criteria for the deployment and configuration of mesh networks. These results both provide valuable insights of wireless multihop performance and prove that FloorNet constitutes a valuable asset to research on wireless mesh networks.

The Living With a Star Space Environment Testbed Payload

Science.gov (United States)

Xapsos, Mike

2015-01-01

This presentation outlines a brief description of the Living With a Star (LWS) Program missions and detailed information about the Space Environment Testbed (SET) payload consisting of a space weather monitor and carrier containing 4 board experiments.

Streak camera recording of interferometer fringes

International Nuclear Information System (INIS)

Parker, N.L.; Chau, H.H.

1977-01-01

The use of an electronic high-speed camera in the streaking mode to record interference fringe motion from a velocity interferometer is discussed. Advantages of this method over the photomultiplier tube-oscilloscope approach are delineated. Performance testing and data for the electronic streak camera are discussed. The velocity profile of a mylar flyer accelerated by an electrically exploded bridge, and the jump-off velocity of metal targets struck by these mylar flyers are measured in the camera tests. Advantages of the streak camera include portability, low cost, ease of operation and maintenance, simplified interferometer optics, and rapid data analysis

Spectroscopy of Kerr Black Holes with Earth- and Space-Based Interferometers.

Science.gov (United States)

Berti, Emanuele; Sesana, Alberto; Barausse, Enrico; Cardoso, Vitor; Belczynski, Krzysztof

2016-09-02

We estimate the potential of present and future interferometric gravitational-wave detectors to test the Kerr nature of black holes through "gravitational spectroscopy," i.e., the measurement of multiple quasinormal mode frequencies from the remnant of a black hole merger. Using population synthesis models of the formation and evolution of stellar-mass black hole binaries, we find that Voyager-class interferometers will be necessary to perform these tests. Gravitational spectroscopy in the local Universe may become routine with the Einstein Telescope, but a 40-km facility like Cosmic Explorer is necessary to go beyond z∼3. In contrast, detectors like eLISA (evolved Laser Interferometer Space Antenna) should carry out a few-or even hundreds-of these tests every year, depending on uncertainties in massive black hole formation models. Many space-based spectroscopical measurements will occur at high redshift, testing the strong gravity dynamics of Kerr black holes in domains where cosmological corrections to general relativity (if they occur in nature) must be significant.

30-lens interferometer for high energy x-rays

Energy Technology Data Exchange (ETDEWEB)

Lyubomirskiy, M., E-mail: lyubomir@esrf.fr; Snigireva, I., E-mail: irina@esrf.fr; Vaughan, G. [European Synchrotron Radiation facility (ESRF), CS 40220, 71, av des Martyrs, F-38043, Grenoble (France); Kohn, V. [National Research Centre “Kurchatov Institute”, 123182, Moscow (Russian Federation); Kuznetsov, S.; Yunkin, V. [Institute of Microelectronics Technology RAS, 142432, Chernogolovka (Russian Federation); Snigirev, A. [Baltic Federal University, 236041, Kaliningrad (Russian Federation)

2016-07-27

We report a hard X-ray multilens interferometer consisting of 30 parallel compound refractive lenses. Under coherent illumination each CRL creates a diffraction limited focal spot - secondary source. An overlapping of coherent beams from these sources resulting in the interference pattern which has a rich longitudinal structure in accordance with the Talbot imaging formalism. The proposed interferometer was experimentally tested at ID11 ESRF beamline for the photon energies 32 keV and 65 keV. The fundamental and fractional Talbot images were recorded with the high resolution CCD camera. An effective source size in the order of 15 µm was determined from the first Talbot image proving that the multilens interferometer can be used as a high resolution beam diagnostic tool.

Direct-reading type microwave interferometer

International Nuclear Information System (INIS)

Matsuura, Kiyokata; Fujita, Junji; Ogata, Atsushi; Haba, Kiichiro.

1977-10-01

A new microwave interferometer has been developed and applied to the electron density measurement on JIPP T-II plasma device. The interferometer generates an output voltage proportional to the number of fringe shifts and also output pulses which indicate the change of electron density for the convenience of data processing, where the resolution is a quarter of fringe shift. The principle is based on the digitization of fringe shifts utilizing the phase detection of microwave signals with two-level modulation of source frequency. With this system and 70 GHz microwave source, a change of electron density as rapid as about 2 x 10 13 cm -3 in 1 ms has been measured at the tokamak operation of JIPP T-II. (auth.)

The Box Model and the Acoustic Sounder, a Case Study

DEFF Research Database (Denmark)

Jensen, Niels Otto; Lundtang Petersen, Erik

1979-01-01

Concentrations of SO2 in a large city during a subsidence situation are predicted as a function of time by means of a simple box model and the predictions are compared to actual SO2 concentration measurements. The agreement between model results and measurements is found to be excellent. The mode...... uses the height of the mixing layer as measured by means of an acoustic sounder. It is demonstrated that this height is a dominant factor in determining the variation of the SO2 concentration...

Plasmonic interferometers: From physics to biosensing applications

Science.gov (United States)

Zeng, Xie

Optical interferometry has a long history and wide range of applications. In recent years, plasmonic interferometer arouses great interest due to its compact size and enhanced light-matter interaction. They have demonstrated attractive applications in biomolecule sensing, optical modulation/switching, and material characterization, etc. In this work, we first propose a practical far-field method to extract the intrinsic phase dispersion, revealing important phase information during interactions among free-space light, nanostructure, and SPs. The proposed approach is confirmed by both simulation and experiment. Then we design novel plasmonic interferometer structure for sensitive optical sensing applications. To overcome two major limitations suffered by previously reported double-slit plasmonic Mach-Zehnder interferometer (PMZI), two new schemes are proposed and investigated. (1) A PMZI based on end-fire coupling improves the SP coupling efficiency and enhance the interference contrast more than 50 times. (2) In another design, a multi-layered metal-insulator-metal PMZI releases the requirement for single-slit illumination, which enables sensitive, high-throughput sensing applications based on intensity modulation. We develop a sensitive, low-cost and high-throughput biosensing platform based on intensity modulation using ring-hole plasmonic interferometers. This biosensor is then integrated with cell-phone-based microscope, which is promising to develop a portable sensor for point-of-care diagnostics, epidemic disease control and food safety monitoring.

Assimilation of Feng-Yun-3B satellite microwave humidity sounder data over land

Science.gov (United States)

Chen, Keyi; Bormann, Niels; English, Stephen; Zhu, Jiang

2018-03-01

The ECMWF has been assimilating Feng-Yun-3B (FY-3B) satellite microwave humidity sounder (MWHS) data over ocean in an operational forecasting system since 24 September 2014. It is more difficult, however, to assimilate microwave observations over land and sea ice than over the open ocean due to higher uncertainties in land surface temperature, surface emissivity and less effective cloud screening. We compare approaches in which the emissivity is retrieved dynamically from MWHS channel 1 [150 GHz (vertical polarization)] with the use of an evolving emissivity atlas from 89 GHz observations from the MWHS onboard NOAA and EUMETSAT satellites. The assimilation of the additional data over land improves the fit of short-range forecasts to other observations, notably ATMS (Advanced Technology Microwave Sounder) humidity channels, and the forecast impacts are mainly neutral to slightly positive over the first five days. The forecast impacts are better in boreal summer and the Southern Hemisphere. These results suggest that the techniques tested allow for effective assimilation of MWHS/FY-3B data over land.

Embedded Sensors and Controls to Improve Component Performance and Reliability -- Bench-scale Testbed Design Report

Energy Technology Data Exchange (ETDEWEB)

Melin, Alexander M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kisner, Roger A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Drira, Anis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Reed, Frederick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-09-01

Embedded instrumentation and control systems that can operate in extreme environments are challenging due to restrictions on sensors and materials. As a part of the Department of Energy's Nuclear Energy Enabling Technology cross-cutting technology development programs Advanced Sensors and Instrumentation topic, this report details the design of a bench-scale embedded instrumentation and control testbed. The design goal of the bench-scale testbed is to build a re-configurable system that can rapidly deploy and test advanced control algorithms in a hardware in the loop setup. The bench-scale testbed will be designed as a fluid pump analog that uses active magnetic bearings to support the shaft. The testbed represents an application that would improve the efficiency and performance of high temperature (700 C) pumps for liquid salt reactors that operate in an extreme environment and provide many engineering challenges that can be overcome with embedded instrumentation and control. This report will give details of the mechanical design, electromagnetic design, geometry optimization, power electronics design, and initial control system design.

A Multi-Vehicles, Wireless Testbed for Networked Control, Communications and Computing

Science.gov (United States)

Murray, Richard; Doyle, John; Effros, Michelle; Hickey, Jason; Low, Steven

2002-03-01

We have constructed a testbed consisting of 4 mobile vehicles (with 4 additional vehicles being completed), each with embedded computing and communications capability for use in testing new approaches for command and control across dynamic networks. The system is being used or is planned to be used for testing of a variety of communications-related technologies, including distributed command and control algorithms, dynamically reconfigurable network topologies, source coding for real-time transmission of data in lossy environments, and multi-network communications. A unique feature of the testbed is the use of vehicles that have second order dynamics. Requiring real-time feedback algorithms to stabilize the system while performing cooperative tasks. The testbed was constructed in the Caltech Vehicles Laboratory and consists of individual vehicles with PC-based computation and controls, and multiple communications devices (802.11 wireless Ethernet, Bluetooth, and infrared). The vehicles are freely moving, wheeled platforms propelled by high performance dotted fairs. The room contains an access points for an 802.11 network, overhead visual sensing (to allow emulation of CI'S signal processing), a centralized computer for emulating certain distributed computations, and network gateways to control and manipulate communications traffic.

An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

International Nuclear Information System (INIS)

Hilbert, Vinzenz; Fuchs, Silvio; Paulus, Gerhard G.; Zastrau, Ulf; Blinne, Alexander; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Förster, Eckhart

2013-01-01

We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed

Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.

Science.gov (United States)

Wan, Xiaoke; Ge, Jian

2012-09-15

A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.

An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers.

Science.gov (United States)

Hilbert, Vinzenz; Blinne, Alexander; Fuchs, Silvio; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Paulus, Gerhard G; Förster, Eckhart; Zastrau, Ulf

2013-09-01

We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

SCaN Testbed Software Development and Lessons Learned

Science.gov (United States)

Kacpura, Thomas J.; Varga, Denise M.

2012-01-01

National Aeronautics and Space Administration (NASA) has developed an on-orbit, adaptable, Software Defined Radio (SDR)Space Telecommunications Radio System (STRS)-based testbed facility to conduct a suite of experiments to advance technologies, reduce risk, and enable future mission capabilities on the International Space Station (ISS). The SCAN Testbed Project will provide NASA, industry, other Government agencies, and academic partners the opportunity to develop and field communications, navigation, and networking technologies in the laboratory and space environment based on reconfigurable, SDR platforms and the STRS Architecture.The SDRs are a new technology for NASA, and the support infrastructure they require is different from legacy, fixed function radios. SDRs offer the ability to reconfigure on-orbit communications by changing software for new waveforms and operating systems to enable new capabilities or fix any anomalies, which was not a previous option. They are not stand alone devices, but required a new approach to effectively control them and flow data. This requires extensive software to be developed to utilize the full potential of these reconfigurable platforms. The paper focuses on development, integration and testing as related to the avionics processor system, and the software required to command, control, monitor, and interact with the SDRs, as well as the other communication payload elements. An extensive effort was required to develop the flight software and meet the NASA requirements for software quality and safety. The flight avionics must be radiation tolerant, and these processors have limited capability in comparison to terrestrial counterparts. A big challenge was that there are three SDRs onboard, and interfacing with multiple SDRs simultaneously complicatesd the effort. The effort also includes ground software, which is a key element for both the command of the payload, and displaying data created by the payload. The verification of

A laser interferometer for measuring straightness and its position based on heterodyne interferometry

International Nuclear Information System (INIS)

Chen Benyong; Zhang Enzheng; Yan Liping; Li Chaorong; Tang Wuhua; Feng Qibo

2009-01-01

Not only the magnitude but also the position of straightness errors are of concern to users. However, current laser interferometers used for measuring straightness seldom give the relative position of the straightness error. To solve this problem, a laser interferometer for measuring straightness and its position based on heterodyne interferometry is proposed. The optical configuration of the interferometer is designed and the measurement principle is analyzed theoretically. Two experiments were carried out. The first experiment verifies the validity and repeatability of the interferometer by measuring a linear stage. Also, the second one for measuring a flexure-hinge stage demonstrates that the interferometer is capable of nanometer measurement accuracy. These results show that this interferometer has advantages of simultaneously measuring straightness error and the relative position with high precision, and a compact structure.

ASE-BAN, a Wireless Body Area Network Testbed

DEFF Research Database (Denmark)

Madsen, Jens Kargaard; Karstoft, Henrik; Toftegaard, Thomas Skjødeberg

2010-01-01

/actuators attached to the body and a host server application. The gateway uses the BlackFin BF533 processor from Analog Devices, and uses Bluetooth for wireless communication. Two types of sensors are attached to the network: an electro-cardio-gram sensor and an oximeter sensor. The testbed has been successfully...

Phase-modulation interferometer for ICF-target characterization

International Nuclear Information System (INIS)

Cooper, D.E.

1981-01-01

Characterization requirements for high gain laser fusion targets are severe. We are required to detect defects on the surfaces of opaque and transparent shells with an amplitude resolution of +- 5 nm and a spatial resolution of 1 to 10 μm. To achieve this we have developed a laser-illuminated phase-modulation interferometer. This instrument is based on a photoelastic polarization modulation technique which allows one to convert phase information into an intensity modulation which can be easily and sensitively measured using ac signal processing techniques. This interferometer has detected path length changes as small as 1 nm and the required spatial resolution is assured by using a microscope objective to focus the probe laser beam down to a small (approx. 1 μm) spot on the surface of a microballoon. The interferometer will soon be coupled to an LSI-11 controlled 4π sphere manipulator which will allow us to automatically inspect the entire surface area of a target sphere

In-line femtosecond common-path interferometer in reflection mode.

Science.gov (United States)

Chandezon, J; Rampnoux, J-M; Dilhaire, S; Audoin, B; Guillet, Y

2015-10-19

An innovative method to perform femtosecond time-resolved interferometry in reflection mode is proposed. The experiment consists in the combined use of a pump-probe setup and of a fully passive in-line femtosecond common-path interferometer. The originality of this interferometer relies on the use of a single birefringent crystal first to generate a pair of phase-locked pulses and second to recombine them to interfere. As predicted by analytical modeling, this interferometer measures the temporal derivative of the ultrafast changes of the complex optical reflection coefficient of the sample. Working conditions are illustrated through picosecond opto-acoustic experiments on a thin film.

Phase-contrast tomographic imaging using an X-ray interferometer

Energy Technology Data Exchange (ETDEWEB)

Momose, A. [Hitachi Ltd, Advanced Research Lab., Saitama (Japan); Takeda, T.; Itai, Y. [Univ. of Tsukuba, Inst. of Clinical Medicine, Ibaraki (Japan); Yoneyama, A. [Hitachi Ltd, Central Resarch Lab., Tokyo (Japan); Hirano, K. [High Energy Accelerator Research Organization, Inst. of Materials Structure Science, Ibaraki (Japan)

1998-05-01

Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays. 35 refs.

Phase-contrast tomographic imaging using an X-ray interferometer

International Nuclear Information System (INIS)

Momose, A.; Takeda, T.; Itai, Y.; Yoneyama, A.; Hirano, K.

1998-01-01

Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays

A novel polarization interferometer for measuring upper atmospheric winds

International Nuclear Information System (INIS)

Ting-Kui, Mu; Chun-Min, Zhang

2010-01-01

A static polarization interferometer for measuring upper atmospheric winds is presented, based on two Savart plates with their optical axes perpendicular to each other. The principle and characteristics of the interferometer are described. The interferometer with a wide field of view can offer a stable benchmark optical path difference over a specified spectral region of 0.55–0.63 μm because there are no quarter wave plates. Since the instrument employs a straight line common-path configuration but without moving parts and slits, it is very compact, simple, inherently robust and has high throughput. The paper is limited to a theoretical analysis. (general)

LOS Throughput Measurements in Real-Time with a 128-Antenna Massive MIMO Testbed

OpenAIRE

Harris, Paul; Zhang, Siming; Beach, Mark; Mellios, Evangelos; Nix, Andrew; Armour, Simon; Doufexi, Angela; Nieman, Karl; Kundargi, Nikhil

2017-01-01

This paper presents initial results for a novel 128-antenna massive Multiple-Input, Multiple- Output (MIMO) testbed developed through Bristol Is Open in collaboration with National Instruments and Lund University. We believe that the results presented here validate the adoption of massive MIMO as a key enabling technology for 5G and pave the way for further pragmatic research by the massive MIMO community. The testbed operates in real-time with a Long-Term Evolution (LTE)-like PHY in Time Div...

A SIMPLE HETERODYNE TEMPORAL SPECKLE-PATTERN INTERFEROMETER

International Nuclear Information System (INIS)

Wong, W. O.; Gao, Z.; Lu, J.

2010-01-01

A common light path design of heterodyne speckle pattern interferometer based on temporal speckle pattern interferometry is proposed for non-contact, full-field and real-time continuous displacement measurement. Double frequency laser is produced by rotating a half wave plate. An experiment was carried out to measure the dynamic displacement of a cantilever plate for testing the proposed common path heterodyne speckle pattern interferometer. The accuracy of displacement measurement was checked by measuring the motion at the mid-point of the plate with a point displacement sensor.

Multiple reflection Michelson interferometer with picometer resolution.

Science.gov (United States)

Pisani, Marco

2008-12-22

A Michelson interferometer based on an optical set-up allowing multiple reflection between two plane mirrors performs the multiplication of the optical path by a factor N, proportionally increasing the resolution of the measurement. A multiplication factor of almost two orders of magnitude has been demonstrated with a simple set-up. The technique can be applied to any interferometric measurement where the classical interferometer limits due to fringe nonlinearities and quantum noise are an issue. Applications in precision engineering, vibration analysis, nanometrology, and spectroscopy are foreseen.

Current Developments in DETER Cybersecurity Testbed Technology

Science.gov (United States)

2015-12-08

Management Experimental cybersecurity research is often inherently risky. An experiment may involve releasing live malware code, operating a real botnet...imagine a worm that can only propagate by first contacting a “propagation service” (T1 constraint), composed with a testbed firewall (T2...experiment. Finally, T1 constraints might be enforced by (1) explicit modification of malware to constrain its behavior, (2) implicit constraints

Broadband sensitivity enhancement of detuned dual-recycled Michelson interferometers with EPR entanglement

Science.gov (United States)

Brown, Daniel D.; Miao, Haixing; Collins, Chris; Mow-Lowry, Conor; Töyrä, Daniel; Freise, Andreas

2017-09-01

We demonstrate the applicability of the EPR entanglement squeezing scheme for enhancing the shot-noise-limited sensitivity of detuned dual-recycled Michelson interferometers. In particular, this scheme is applied to the GEO600 interferometer. The effect of losses throughout the interferometer, arm length asymmetries, and imperfect separation of the signal and idler beams is considered.

Noise cancellation properties of displacement noise free interferometer

International Nuclear Information System (INIS)

Sato, Shuichi; Kawamura, Seiji; Nishizawa, Atsushi; Chen Yanbei

2010-01-01

We have demonstrated the practical feasibility of a displacement- and frequency-noise-free laser interferometer (DFI) by partially implementing a recently proposed optical configuration using bi-directional Mach-Zehnder interferometers (MZIs). The noise cancellation efficiency was evaluated by comparing the displacement noise spectrum of the MZIs and the DFI, demonstrating up to 50 dB of noise cancellation. In addition, the possible extension of DFI as QND device is explored.

The CryoSat Interferometer after 6 years in orbit: calibration and achievable performance

Science.gov (United States)

Scagliola, Michele; Fornari, Marco; De Bartolomei, Maurizio; Bouffard, Jerome; Parrinello, Tommaso

2016-04-01

The main payload of CryoSat is a Ku-band pulse width limited radar altimeter, called SIRAL (Synthetic interferometric radar altimeter). When commanded in SARIn (synthetic aperture radar interferometry) mode, through coherent along-track processing of the returns received from two antennas, the interferometric phase related to the first arrival of the echo is used to retrieve the angle of arrival of the scattering in the across-track direction. In fact, the across-track echo direction can be derived by exploiting the precise knowledge of the baseline vector (i.e. the vector between the two antennas centers of phase) and simple geometry. The end-to-end calibration strategy for the CryoSat interferometer consists on in-orbit calibration campaigns following the approach described in [1]. From the beginning of the CryoSat mission, about once a year the interferometer calibration campaigns have been periodically performed by rolling left and right the spacecraft of about ±0.4 deg. This abstract is aimed at presenting our analysis of the calibration parameters and of the achievable performance of the CryoSat interferometer over the 6 years of mission. Additionally, some further studies have been performed to assess the accuracy of the roll angle computed on ground as function of the aberration (the apparent displacement of a celestial object from its true position, caused by the relative motion of the observer and the object) correction applied to the attitude quaternions, provided by the Star Tracker mounted on-board. In fact, being the roll information crucial to obtain an accurate estimate of the angle of arrival, the data from interferometer calibration campaigns have been used to verify how the application of the aberration correction affects the roll information and, in turns, the measured angle of arrival. [1] Galin, N.; Wingham, D.J.; Cullen, R.; Fornari, M.; Smith, W.H.F.; Abdalla, S., "Calibration of the CryoSat-2 Interferometer and Measurement of Across

Construction of test-bed system of voltage management system to ...

African Journals Online (AJOL)

Construction of test-bed system of voltage management system to apply physical power system. ... Journal of Fundamental and Applied Sciences ... system of voltage management system (VMS) in order to apply physical power system.

Development of a Testbed for Wireless Underground Sensor Networks

Directory of Open Access Journals (Sweden)

Mehmet C. Vuran

2010-01-01

Full Text Available Wireless Underground Sensor Networks (WUSNs constitute one of the promising application areas of the recently developed wireless sensor networking techniques. WUSN is a specialized kind of Wireless Sensor Network (WSN that mainly focuses on the use of sensors that communicate through soil. Recent models for the wireless underground communication channel are proposed but few field experiments were realized to verify the accuracy of the models. The realization of field WUSN experiments proved to be extremely complex and time-consuming in comparison with the traditional wireless environment. To the best of our knowledge, this is the first work that proposes guidelines for the development of an outdoor WUSN testbed with the goals of improving the accuracy and reducing of time for WUSN experiments. Although the work mainly aims WUSNs, many of the presented practices can also be applied to generic WSN testbeds.

Germanium on silicon mid-infrared waveguides and Mach-Zehnder interferometers

NARCIS (Netherlands)

Malik, A.; Muneeb, M.; Shimura, Y.; Campenhout, van J.; Loo, van de R.; Roelkens, G.C.

2013-01-01

In this paper we describe Ge-on-Si waveguides and Mach-Zehnder interferometers operating in the 5.2 - 5.4 µm wavelength range. 3dB/cm waveguide losses and Mach-Zehnder interferometers with 20dB extinction ratio are presented.

Implementation of a Wireless Time Distribution Testbed Protected with Quantum Key Distribution

Energy Technology Data Exchange (ETDEWEB)

Bonior, Jason D [ORNL; Evans, Philip G [ORNL; Sheets, Gregory S [ORNL; Jones, John P [ORNL; Flynn, Toby H [ORNL; O' Neil, Lori Ross [Pacific Northwest National Laboratory (PNNL); Hutton, William [Pacific Northwest National Laboratory (PNNL); Pratt, Richard [Pacific Northwest National Laboratory (PNNL); Carroll, Thomas E. [Pacific Northwest National Laboratory (PNNL)

2017-01-01

Secure time transfer is critical for many timesensitive applications. the Global Positioning System (GPS) which is often used for this purpose has been shown to be susceptible to spoofing attacks. Quantum Key Distribution offers a way to securely generate encryption keys at two locations. Through careful use of this information it is possible to create a system that is more resistant to spoofing attacks. In this paper we describe our work to create a testbed which utilizes QKD and traditional RF links. This testbed will be used for the development of more secure and spoofing resistant time distribution protocols.

Improved double-pass michelson interferometer

Science.gov (United States)

Schindler, R. A.

1978-01-01

Interferometer design separates beams by offsetting centerlines of cat's-eye retroreflectors vertically rather than horizontally. Since beam splitter is insensitive to minimum-thickness condition in this geometry, relatively-low-cost, optically flat plate can be used.

Quasi-quadrature interferometer for plasma density radial profile measurements

International Nuclear Information System (INIS)

Lowenthal, D.D.; Hoffman, A.L.

1979-01-01

A cw Mach Zehnder multichannel interferometer has been developed to measure time-dependent fractional fringe shifts with an accuracy of one-fortieth fringe. The design is quasi-quadrature in that known phase shifts, introduced in the reference beam, are time multiplexed with the normal reference beam. This technique requires only one detector per interferometer channel as compared to two detectors for most quadrature designs. The quadrature information makes the sense of density changes unambiguous, it automatically calibrates the instrument during the plasma event, and it makes fringe shift measurements virtually independent of fringe contrast fluctuations caused by plasma refractive and/or absorptive effects. The interferometer optical design is novel in that the electro-optic crystal used to introduce the 90 0 phase shifts is located in the common 2-mm-diam HeNe entrance beam to the interferometer, by exploiting polarization techniques, rather than in the expanded 1--2-cm reference beam itself. This arrangement greatly reduces the size, cost, and high-voltage requirements for the phase modulating crystal

Ekonomiczne i społeczne następstwa globalizacji

OpenAIRE

Kaczmarek, Bartłomiej

2014-01-01

The subject of this article in an analysis of the globalisation process in economic and social areas. The author describes the main spheres of globalisation such as economic and political integration, the declining role of nation states, cultural homogenisation and the increasing significance of transnational corporations. The advantages and disadvantages of globalisation are discussed. The author also indicates differences between regions that benefit from globalisation. Th...

Airborne Deployment and Calibration of Microwave Atmospheric Sounder on 6U CubeSat

Science.gov (United States)

Padmanabhan, S.; Brown, S. T.; Lim, B.; Kangaslahti, P.; Russell, D.; Stachnik, R. A.

2015-12-01

To accurately predict how the distribution of extreme events may change in the future we need to understand the mechanisms that influence such events in our current climate. Our current observing system is not well-suited for observing extreme events globally due to the sparse sampling and in-homogeneity of ground-based in-situ observations and the infrequent revisit time of satellite observations. Observations of weather extremes, such as extreme precipitation events, temperature extremes, tropical and extra-tropical cyclones among others, with temporal resolution on the order of minutes and spatial resolution on the order of few kms (cost passive microwave sounding and imaging sensors on CubeSats that would work in concert with traditional flagship observational systems, such as those manifested on large environmental satellites (i.e. JPSS,WSF,GCOM-W), to monitor weather extremes. A 118/183 GHz sensor would enable observations of temperature and precipitation extremes over land and ocean as well as tropical and extra-tropical cyclones. This proposed project would enable low cost, compact radiometer instrumentation at 118 and 183 GHz that would fit in a 6U Cubesat with the objective of mass-producing this design to enable a suite of small satellites to image the key geophysical parameters needed to improve prediction of extreme weather events. We take advantage of past and current technology developments at JPL viz. HAMSR (High Altitude Microwave Scanning Radiometer), Advanced Component Technology (ACT'08) to enable low-mass, low-power high frequency airborne radiometers. In this paper, we will describe the design and implementation of the 118 GHz temperature sounder and 183 GHz humidity sounder on the 6U CubeSat. In addition, we will discuss the maiden airborne deployment of the instrument during the Plain Elevated Convection at Night (PECAN) experiment. The successful demonstration of this instrument on the 6U CubeSat would pave the way for the development of a

Phased Array Antenna Testbed Development at the NASA Glenn Research Center

Science.gov (United States)

Lambert, Kevin M.; Kubat, Gregory; Johnson, Sandra K.; Anzic, Godfrey

2003-01-01

Ideal phased array antennas offer advantages for communication systems, such as wide-angle scanning and multibeam operation, which can be utilized in certain NASA applications. However, physically realizable, electronically steered, phased array antennas introduce additional system performance parameters, which must be included in the evaluation of the system. The NASA Glenn Research Center (GRC) is currently conducting research to identify these parameters and to develop the tools necessary to measure them. One of these tools is a testbed where phased array antennas may be operated in an environment that simulates their use. This paper describes the development of the testbed and its use in characterizing a particular K-Band, phased array antenna.

A Matlab-Based Testbed for Integration, Evaluation and Comparison of Heterogeneous Stereo Vision Matching Algorithms

Directory of Open Access Journals (Sweden)

Raul Correal

2016-11-01

Full Text Available Stereo matching is a heavily researched area with a prolific published literature and a broad spectrum of heterogeneous algorithms available in diverse programming languages. This paper presents a Matlab-based testbed that aims to centralize and standardize this variety of both current and prospective stereo matching approaches. The proposed testbed aims to facilitate the application of stereo-based methods to real situations. It allows for configuring and executing algorithms, as well as comparing results, in a fast, easy and friendly setting. Algorithms can be combined so that a series of processes can be chained and executed consecutively, using the output of a process as input for the next; some additional filtering and image processing techniques have been included within the testbed for this purpose. A use case is included to illustrate how these processes are sequenced and its effect on the results for real applications. The testbed has been conceived as a collaborative and incremental open-source project, where its code is accessible and modifiable, with the objective of receiving contributions and releasing future versions to include new algorithms and features. It is currently available online for the research community.

Instrument development for atmospheric radiation measurement (ARM): Status of the Atmospheric Emitted Radiance Interferometer - extended Resolution (AERI-X), the Solar Radiance Transmission Interferometer (SORTI), and the Absolute Solar Transmission Inferometer (ASTI)

Energy Technology Data Exchange (ETDEWEB)

Murcray, F.; Stephen, T.; Kosters, J. [Univ. of Denver, CO (United States)

1996-04-01

This paper describes three instruments currently under developemnt for the Atmospheric Radiation Measurement (ARM) Program at the University of Denver: the AERI-X (Atmospheric Emitted Radiance Interferometer-Extended Resolution) and the SORTI (Solar R adiance Transmission Interferometer), and ASTI (Absolute Solar transmission Interferometer).

Measuring Earth: Current status of the GRACE Follow-On Laser Ranging Interferometer

Science.gov (United States)

Schütze, Daniel; LRI Team

2016-05-01

The GRACE mission that was launched in 2002 has impressively proven the feasibility of low-orbit satellite-to-satellite tracking for Earth gravity observations. Especially mass transport related to Earth's hydrological system could be well resolved both spatially and temporally. This allows to study processes such as polar ice sheet decline and ground water depletion in great detail. Owing to GRACE's success, NASA and GFZ will launch the successor mission GRACE Follow-On in 2017. In addition to the microwave ranging system, GRACE Follow-On will be the first mission to use a Laser Ranging Interferometer as technology demonstrator to track intersatellite distance changes with unprecedented precision. This new ranging device inherits some of the technologies which have been developed for the future spaceborne gravitational wave detector LISA. I will present the architecture of the Laser Ranging Interferometer, point out similarities and differences to LISA, and conclude with the current status of the flight hardware production.

Building a ROS-Based Testbed for Realistic Multi-Robot Simulation: Taking the Exploration as an Example

Directory of Open Access Journals (Sweden)

Zhi Yan

2017-09-01

Full Text Available While the robotics community agrees that the benchmarking is of high importance to objectively compare different solutions, there are only few and limited tools to support it. To address this issue in the context of multi-robot systems, we have defined a benchmarking process based on experimental designs, which aimed at improving the reproducibility of experiments by making explicit all elements of a benchmark such as parameters, measurements and metrics. We have also developed a ROS (Robot Operating System-based testbed with the goal of making it easy for users to validate, benchmark, and compare different algorithms including coordination strategies. Our testbed uses the MORSE (Modular OpenRobots Simulation Engine simulator for realistic simulation and a computer cluster for decentralized computation. In this paper, we present our testbed in details with the architecture and infrastructure, the issues encountered in implementing the infrastructure, and the automation of the deployment. We also report a series of experiments on multi-robot exploration, in order to demonstrate the capabilities of our testbed.

Parametric instability in GEO 600 interferometer

International Nuclear Information System (INIS)

Gurkovsky, A.G.; Vyatchanin, S.P.

2007-01-01

We present analysis of undesirable effect of parametric instability in signal recycled GEO 600 interferometer. The basis for this effect is provided by excitation of additional (Stokes) optical mode, having frequency ω 1 , and mirror elastic mode, having frequency ω m , when the optical energy stored in the main FP cavity mode, having frequency ω 0 , exceeds a certain threshold and detuning Δ=ω 0 -ω 1 -ω m is small. We discuss the potential of observing parametric instability and its precursors in GEO 600 interferometer. This approach provides the best option to get familiar with this phenomenon, to develop experimental methods to depress it and to test the effectiveness of these methods in situ

Reducing the first-order Doppler shift in a Sagnac interferometer

NARCIS (Netherlands)

Hannemann, S.; Salumbides, E.J.; Ubachs, W.M.G.

2007-01-01

We demonstrate a technique to reduce first-order Doppler shifts in crossed atomic/molecular and laser beam setups by aligning two counterpropagating laser beams as part of a Sagnac interferometer. Interference fringes on the exit port of the interferometer reveal minute deviations from perfect

All-silicon thermal independent Mach-Zehnder interferometer with multimode waveguides

DEFF Research Database (Denmark)

Guan, Xiaowei; Frandsen, Lars Hagedorn

2016-01-01

A novel all-silicon thermal independent Mach-Zehnder interferometer consisting of two multimode waveguide arms having equal lengths and widths but transmitting different modes is proposed and experimentally demonstrated. The interferometer has a temperature sensitivity smaller than 8pm/°C in a wa...

Optical displacement measurement with GaAs/AlGaAs-based monolithically integrated Michelson interferometers

OpenAIRE

Hofstetter, Daniel; Zappe, H. P.; Dändliker, René

2008-01-01

Two monolithically integrated optical displacement sensors fabricated in the GaAs/AlGaAs material system are reported. These single-chip microsystems are configured as Michelson interferometers and comprise a distributed Bragg reflector (DBR) laser, photodetectors, phase shifters, and waveguide couplers. While the use of a single Michelson interferometer allows measurement of displacement magnitude only, a double Michelson interferometer with two interferometer signals in phase quadrature als...

Fine art of computing nulling interferometer maps

Science.gov (United States)

Hénault, F.

2008-07-01

Spaceborne nulling interferometers are often characterized by means of their nulling ratio, which is defined as the deepest possible extinction of one target star supposed to harbor an extra-solar system. Herein is shown that another parameter, which is the transmitting efficiency of nearby bright fringes, is also of prime importance. More generally, "nulling maps" formed by the whole destructive and constructive fringe pattern projected on-sky, are found to be very sensitive on the design of some subsystems constituting the interferometer. In particular, we consider Spatial Filtering (SF) and Achromatic Phase Shifter (APS) devices, both required achieving planet detection and characterization. Consequences of the SF choice (pinhole or single-mode optical fiber) and APS properties (with or without induced pupil-flip) are discussed, for both monochromatic and polychromatic cases. Examples of numerical simulations are provided for single Bracewell interferometer, Angel cross and X-array configurations, demonstrating noticeable differences in the aspect of resulting nulling maps. It is concluded that both FS and APS designs exhibit variable capacities for serendipitous planet discovery.

Recent Successes and Future Plans for NASA's Space Communications and Navigation Testbed on the International Space Station

Science.gov (United States)

Reinhart, Richard C.; Sankovic, John M.; Johnson, Sandra K.; Lux, James P.; Chelmins, David T.

2014-01-01

Flexible and extensible space communications architectures and technology are essential to enable future space exploration and science activities. NASA has championed the development of the Space Telecommunications Radio System (STRS) software defined radio (SDR) standard and the application of SDR technology to reduce the costs and risks of using SDRs for space missions, and has developed an on-orbit testbed to validate these capabilities. The Space Communications and Navigation (SCaN) Testbed (previously known as the Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT)) is advancing SDR, on-board networking, and navigation technologies by conducting space experiments aboard the International Space Station. During its first year(s) on-orbit, the SCaN Testbed has achieved considerable accomplishments to better understand SDRs and their applications. The SDR platforms and software waveforms on each SDR have over 1500 hours of operation and are performing as designed. The Ka-band SDR on the SCaN Testbed is NASAs first space Ka-band transceiver and is NASA's first Ka-band mission using the Space Network. This has provided exciting opportunities to operate at Ka-band and assist with on-orbit tests of NASA newest Tracking and Data Relay Satellites (TDRS). During its first year, SCaN Testbed completed its first on-orbit SDR reconfigurations. SDR reconfigurations occur when implementing new waveforms on an SDR. SDR reconfigurations allow a radio to change minor parameters, such as data rate, or complete functionality. New waveforms which provide new capability and are reusable across different missions provide long term value for reconfigurable platforms such as SDRs. The STRS Standard provides guidelines for new waveform development by third parties. Waveform development by organizations other than the platform provider offers NASA the ability to develop waveforms itself and reduce its dependence and costs on the platform developer. Each of these

A MIMO-OFDM Testbed for Wireless Local Area Networks

Directory of Open Access Journals (Sweden)

Conrat Jean-Marc

2006-01-01

Full Text Available We describe the design steps and final implementation of a MIMO OFDM prototype platform developed to enhance the performance of wireless LAN standards such as HiperLAN/2 and 802.11, using multiple transmit and multiple receive antennas. We first describe the channel measurement campaign used to characterize the indoor operational propagation environment, and analyze the influence of the channel on code design through a ray-tracing channel simulator. We also comment on some antenna and RF issues which are of importance for the final realization of the testbed. Multiple coding, decoding, and channel estimation strategies are discussed and their respective performance-complexity trade-offs are evaluated over the realistic channel obtained from the propagation studies. Finally, we present the design methodology, including cross-validation of the Matlab, C++, and VHDL components, and the final demonstrator architecture. We highlight the increased measured performance of the MIMO testbed over the single-antenna system.

Quantum noise in laser-interferometer gravitational-wave detectors with a heterodyne readout scheme

International Nuclear Information System (INIS)

Buonanno, Alessandra; Chen Yanbei; Mavalvala, Nergis

2003-01-01

We analyze and discuss the quantum noise in signal-recycled laser interferometer gravitational-wave detectors, such as Advanced LIGO, using a heterodyne readout scheme and taking into account the optomechanical dynamics. Contrary to homodyne detection, a heterodyne readout scheme can simultaneously measure more than one quadrature of the output field, providing an additional way of optimizing the interferometer sensitivity, but at the price of additional noise. Our analysis provides the framework needed to evaluate whether a homodyne or heterodyne readout scheme is more optimal for second generation interferometers from an astrophysical point of view. As a more theoretical outcome of our analysis, we show that as a consequence of the Heisenberg uncertainty principle the heterodyne scheme cannot convert conventional interferometers into (broadband) quantum non-demolition interferometers

A Fabry-Perot interferometer system for high-speed velocity measurement

NARCIS (Netherlands)

Cheng, L.K.; Bruinsma, A.J.A.; Prinse, W.C.; Smorenburg, C.

1997-01-01

The Fabry-Perot Velocity Interferometer System (F-PVIS) is designed and built for measuring the Doppler shift of light by recording positional changes in the interferometric pattern behind the Fabry-Perot interferometer. The velocity of a surface can be deduced from the Doppler shift which is caused

A Testbed Environment for Buildings-to-Grid Cyber Resilience Research and Development

Energy Technology Data Exchange (ETDEWEB)

Sridhar, Siddharth; Ashok, Aditya; Mylrea, Michael E.; Pal, Seemita; Rice, Mark J.; Gourisetti, Sri Nikhil Gup

2017-09-19

The Smart Grid is characterized by the proliferation of advanced digital controllers at all levels of its operational hierarchy from generation to end consumption. Such controllers within modern residential and commercial buildings enable grid operators to exercise fine-grained control over energy consumption through several emerging Buildings-to-Grid (B2G) applications. Though this capability promises significant benefits in terms of operational economics and improved reliability, cybersecurity weaknesses in the supporting infrastructure could be exploited to cause a detrimental effect and this necessitates focused research efforts on two fronts. First, the understanding of how cyber attacks in the B2G space could impact grid reliability and to what extent. Second, the development and validation of cyber-physical application-specific countermeasures that are complementary to traditional infrastructure cybersecurity mechanisms for enhanced cyber attack detection and mitigation. The PNNL B2G testbed is currently being developed to address these core research needs. Specifically, the B2G testbed combines high-fidelity buildings+grid simulators, industry-grade building automation and Supervisory Control and Data Acquisition (SCADA) systems in an integrated, realistic, and reconfigurable environment capable of supporting attack-impact-detection-mitigation experimentation. In this paper, we articulate the need for research testbeds to model various B2G applications broadly by looking at the end-to-end operational hierarchy of the Smart Grid. Finally, the paper not only describes the architecture of the B2G testbed in detail, but also addresses the broad spectrum of B2G resilience research it is capable of supporting based on the smart grid operational hierarchy identified earlier.

Comment on "Rovibrational quantum interferometers and gravitational waves"

OpenAIRE

Khriplovich, I. B.; Lamoreaux, S. K.; Sushkov, A. O.; Sushkov, O. P.

2009-01-01

In a recent paper, Wicht, L\\"ammerzahl, Lorek, and Dittus [Phys. Rev. {\\bf A 78}, 013610 (2008)] come to the conclusion that a molecular rotational-vibrational quantum interferometer may possess the sensitivity necessary to detect gravitational waves. We do not agree with their results and demonstrate here that the true sensitivity of such interferometer is many orders of magnitude worse than that claimed in the mentioned paper. In the present comment we estimate the expected energy shifts an...

Two-photon quantum interference in a Michelson interferometer

International Nuclear Information System (INIS)

Odate, Satoru; Wang Haibo; Kobayashi, Takayoshi

2005-01-01

We have observed two-photon quantum interference in a Michelson interferometer. For the first time, we experimentally demonstrated two-photon quantum interference patterns, which show the transition from nonsubwavelength interference fringes to the general subwavelength interference. At the same time, a photon bunching effect was also shown by a postselection. The |1, 1> state with a single photon in a mode corresponding to each arm of the interferometer was exclusively postselected by using path difference between two arms

The POLIS interferometer for ponderomotive squeezed light generation

Energy Technology Data Exchange (ETDEWEB)

Calloni, Enrico [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Conte, Andrea [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); De Laurentis, Martina, E-mail: martina.delaurentis@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Naticchioni, Luca [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); Puppo, Paola [INFN, Sezione di Roma1 (Italy); Ricci, Fulvio [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy)

2016-07-11

POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

UARS Improved Stratospheric and Mesospheric Sounder (ISAMS) Level 3AL V010 (UARIS3AL) at GES DISC

Data.gov (United States)

National Aeronautics and Space Administration — The Improved Stratospheric and Mesospheric Sounder (ISAMS) Level 3AL data product consists of daily, 4 degree increment latitude-ordered vertical profiles of...

Visible light dynamical diffraction in a 1-D photonic crystal-based interferometer with an extremely thin spacer layer

International Nuclear Information System (INIS)

Prudnikov, I.R.

2016-01-01

Properties of light diffraction in a Fabry–Pérot-like interferometer composed of two 1-D photonic crystals and a nanometer-thick spacer layer are analytically investigated. It is shown that the resonant enhancement of light wave intensity in such a layer is possible because of light dynamical diffraction from the photonic crystals of the interferometer. Numerical simulations of (i) light reflectivity and transmittance curves of the interferometer having an ultra-thin spacer layer (its thickness changes from less than 1 nm to about 10 nm) and (ii) the resonant distribution of the light wave intensity in the vicinity of the layer are performed. Based on the numerical simulations, potentialities for the determination of the structural parameters (e.g., thicknesses and refraction indexes) of ultra-thin spacer films are discussed. A difference is found to appear in resonant intensity enhancements inside the ultra-thin spacer layers between s- and p-polarized light waves.

Using multi-beam echo sounder backscatter data for sediment classification in very shallow water environments

NARCIS (Netherlands)

Amiri-Simkooei, A.R.; Snellen, M.; Simons, D.G.

2009-01-01

In a recent work described in Ref. [1], an angle-independent methodology was developed to use the multi-beam echo sounder backscatter (MBES) data for the seabed sediment classification. The method employs the backscatter data at a certain angle to obtain the number of sediment classes and to

The microwave limb sounder for the Upper Atmosphere Research Satellite

Science.gov (United States)

Waters, J. W.; Peckham, G. E.; Suttie, R. A.; Curtis, P. D.; Maddison, B. J.; Harwood, R. S.

1988-01-01

The Microwave Limb Sounder was designed to map the concentrations of trace gases from the stratosphere to the lower thermosphere, to improve understanding of the photochemical reactions which take place in this part of the atmosphere. The instrument will measure the intensity of thermal radiation from molecules in the atmosphere at frequencies corresponding to rotational absorption bands of chlorine monoxide, ozone, and water vapor. Molecular concentration profiles will be determined over a height range of 15 to 80 km (20 to 45 km for C10). The 57 deg inclination orbit proposed for the Upper Atmosphere Research Satellite will allow global coverage.

Dedicated Low Latitude Diurnal CO2 Frost Observation Campaigns by the Mars Climate Sounder

Science.gov (United States)

Piqueux, S.; Kass, D. M.; Kleinboehl, A.; Hayne, P. O.; Heavens, N. G.; McCleese, D. J.; Schofield, J. T.; Shirley, J. H.

2017-12-01

In December 2016 (Ls≈280, MY33) and July 2017 (Ls≈30, MY34), the Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter (MRO) conducted two distinct observation campaigns. The first one aimed at 1) confirming the presence of low latitude diurnal CO2 frost on Mars, and 2) refining the estimated mass of carbon dioxide condensed at the surface, whereas the second campaign was designed to 3) search for temporally and spatially varying spectral characteristics indicative of frost properties (i.e., crystal size, contamination, etc.) and relationship to the regolith. To meet these goals, MCS acquired thermal infrared observations of the surface and atmosphere at variable local times (≈1.70-3.80 h Local True Solar Time) and in the 10°-50°N latitude band where very low thermal inertia material (frost distribution and spectral properties. In addition, pre-frost deposition surface cooling rates are found to be consistent with those predicted by numerical models (i.e., 1-2K per hour). Finally, we observe buffered surface temperatures near the local frost point, indicating a surface emissivity ≈1. (i.e., optically thin frost layers, or dust contaminated frost, or slab-like ice) and no discernable frost metamorphism. We will present a detailed analysis of these new and unique observations, and elaborate on the potential relationship between the regolith and this recurring frost cycle.

UARS Improved Stratospheric and Mesospheric Sounder (ISAMS) Level 3AT V010 (UARIS3AT) at GES DISC

Data.gov (United States)

National Aeronautics and Space Administration — The Improved Stratospheric and Mesospheric Sounder (ISAMS) Level 3AT data product consists of daily, 65.536 second interval time-ordered vertical profiles of...

A demonstration of remote survey and characterization of a buried waste site using the SRIP [Soldier Robot Interface Project] testbed

International Nuclear Information System (INIS)

Burks, B.L.; Richardson, B.S.; Armstrong, G.A.; Hamel, W.R.; Jansen, J.F.; Killough, S.M.; Thompson, D.H.; Emery, M.S.

1990-01-01

During FY 1990, the Oak Ridge National Laboratory (ORNL) supported the Department of Energy (DOE) Environmental Restoration and Waste Management (ER ampersand WM) Office of Technology Development through several projects including the development of a semiautonomous survey of a buried waste site using a remotely operated all-terrain robotic testbed borrowed from the US Army. The testbed was developed for the US Army's Human Engineering Laboratory (HEL) for the US Army's Soldier Robot Interface Project (SRIP). Initial development of the SRIP testbed was performed by a team including ORNL, HEL, Tooele Army Depot, and Odetics, Inc., as an experimental testbed for a variety of human factors issues related to military applications of robotics. The SRIP testbed was made available to the DOE and ORNL for the further development required for a remote landfill survey. The robot was modified extensively, equipped with environmental sensors, and used to demonstrate an automated remote survey of Solid Waste Storage Area No. 3 (SWSA 3) at ORNL on Tuesday, September 18, 1990. Burial trenches in this area containing contaminated materials were covered with soil nearly twenty years ago. This paper describes the SRIP testbed and work performed in FY 1990 to demonstrate a semiautonomous landfill survey at ORNL. 5 refs

On-wire lithography-generated molecule-based transport junctions: a new testbed for molecular electronics.

Science.gov (United States)

Chen, Xiaodong; Jeon, You-Moon; Jang, Jae-Won; Qin, Lidong; Huo, Fengwei; Wei, Wei; Mirkin, Chad A

2008-07-02

On-wire lithography (OWL) fabricated nanogaps are used as a new testbed to construct molecular transport junctions (MTJs) through the assembly of thiolated molecular wires across a nanogap formed between two Au electrodes. In addition, we show that one can use OWL to rapidly characterize a MTJ and optimize gap size for two molecular wires of different dimensions. Finally, we have used this new testbed to identify unusual temperature-dependent transport mechanisms for alpha,omega-dithiol terminated oligo(phenylene ethynylene).

Real-Time Simulation and Hardware-in-the-Loop Testbed for Distribution Synchrophasor Applications

Directory of Open Access Journals (Sweden)

Matthias Stifter

2018-04-01

Full Text Available With the advent of Distribution Phasor Measurement Units (D-PMUs and Micro-Synchrophasors (Micro-PMUs, the situational awareness in power distribution systems is going to the next level using time-synchronization. However, designing, analyzing, and testing of such accurate measurement devices are still challenging. Due to the lack of available knowledge and sufficient history for synchrophasors’ applications at the power distribution level, the realistic simulation, and validation environments are essential for D-PMU development and deployment. This paper presents a vendor agnostic PMU real-time simulation and hardware-in-the-Loop (PMU-RTS-HIL testbed, which helps in multiple PMUs validation and studies. The network of real and virtual PMUs was built in a full time-synchronized environment for PMU applications’ validation. The proposed testbed also includes an emulated communication network (CNS layer to replicate bandwidth, packet loss and collisions conditions inherent to the PMUs data streams’ issues. Experimental results demonstrate the flexibility and scalability of the developed PMU-RTS-HIL testbed by producing large amounts of measurements under typical normal and abnormal distribution grid operation conditions.

Feedback-stabilized dual-beam laser interferometer for plasma measurements

International Nuclear Information System (INIS)

Yasuda, A.; Kanai, Y.; Kusunoki, J.; Kawahata, K.; Takeda, S.

1980-01-01

A stabilized laser interferometer is proposed with two beams as the light source. The fringe shift for a 0.63 μm beam of a He--Ne laser is used to stabilize the interferometer against the effect of mechanical vibrations via a feedback controlled speaker coil, while another beam of 3.39 μm, for which consequently the effect of the mechanical vibrations is excluded, is used to measure the plasma density. A stability of approx.1/500 of one fringe for 0.63 μm is obtained during a long period for frequencies lower than a few Hz. The stability for higher frequencies is limited to approx.1/30 of one fringe for 0.63 μm, which correspondes to approx.1/200 of one fringe for 3.39 μm, by the acoustic noise picked up by the speaker coil. Furthermore, the total accuracy is limited by the detector noise to approx.1/60 of one fringe for 3.39 μm, which corresponds to a line electron density of approx.5 x 10 14 cm -2 . The detector noise may be reduced by cooling the detector. The advantage of this technique over the single-laser technique is that the frequency response of the interferometer extends down to zero frequency. The interferometer is tested with the measurement of a plasma in a dynamic magnetic arcjet. Since the effect of the neutral gas background is reduced in the present interferometer, the application has an advantage for the diagnostics of plasmas produced in high pressure gases

Embedded Sensors and Controls to Improve Component Performance and Reliability -- Loop-scale Testbed Design Report

Energy Technology Data Exchange (ETDEWEB)

Melin, Alexander M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kisner, Roger A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-09-01

Embedded instrumentation and control systems that can operate in extreme environments are challenging to design and operate. Extreme environments limit the options for sensors and actuators and degrade their performance. Because sensors and actuators are necessary for feedback control, these limitations mean that designing embedded instrumentation and control systems for the challenging environments of nuclear reactors requires advanced technical solutions that are not available commercially. This report details the development of testbed that will be used for cross-cutting embedded instrumentation and control research for nuclear power applications. This research is funded by the Department of Energy's Nuclear Energy Enabling Technology program's Advanced Sensors and Instrumentation topic. The design goal of the loop-scale testbed is to build a low temperature pump that utilizes magnetic bearing that will be incorporated into a water loop to test control system performance and self-sensing techniques. Specifically, this testbed will be used to analyze control system performance in response to nonlinear and cross-coupling fluid effects between the shaft axes of motion, rotordynamics and gyroscopic effects, and impeller disturbances. This testbed will also be used to characterize the performance losses when using self-sensing position measurement techniques. Active magnetic bearings are a technology that can reduce failures and maintenance costs in nuclear power plants. They are particularly relevant to liquid salt reactors that operate at high temperatures (700 C). Pumps used in the extreme environment of liquid salt reactors provide many engineering challenges that can be overcome with magnetic bearings and their associated embedded instrumentation and control. This report will give details of the mechanical design and electromagnetic design of the loop-scale embedded instrumentation and control testbed.

Applications and Lessons Learned using Data from the Atmospheric Infrared Sounder

Science.gov (United States)

Ray, S. E.; Fetzer, E. J.; Olsen, E. T.; Lambrigtsen, B.; Pagano, T. S.; Teixeira, J.; Licata, S. J.; Hall, J. R.

2016-12-01

Applications and Lessons Learned using Data from the Atmospheric Infrared SounderSharon Ray, Jet Propulsion Laboratory, California Institute of Technology The Atmospheric Infrared Sounder (AIRS) on NASA's Aqua spacecraft has been returning daily global observations of Earth's atmospheric constituents and properties since 2002. With a 12-year data record and daily, global observations in near real-time, AIRS can play a role in applications that fall under many of the NASA Applied Sciences focus areas. AIRS' involvement in applications is two years in, so what have we learned and what are the pitfalls? AIRS has made gains in drought applications with products under consideration for inclusion in the U.S. Drought Monitor national map, as also with volcano rapid response with an internal alert system and automated products to help characterize plume extent. Efforts are underway with cold air aloft for aviation, influenza outbreak prediction, and vector borne disease. But challenges have occurred both in validation and in crossing the "valley of death" between products and decision makers. AIRS now has improved maps of standard products to be distributed in near real-time via NASA LANCE and by the Goddard DAAC as part of the Obama's administration Big Earth Data Initiative. In addition internal tools have been developed to support development and distribution of our application products. This talk will communicate the status of the AIRS applications effort along with lessons learned, and provide examples of new product imagery designed to best communicate AIRS data.

Self-alignment of a compact large-area atomic Sagnac interferometer

International Nuclear Information System (INIS)

Tackmann, G; Berg, P; Schubert, C; Abend, S; Gilowski, M; Ertmer, W; Rasel, E M

2012-01-01

We report on the realization of a compact atomic Mach-Zehnder-type Sagnac interferometer of 13.7 cm length, which covers an area of 19 mm 2 previously reported only for large thermal beam interferometers. According to Sagnac's formula, which holds for both light and atoms, the sensitivity for rotation rates increases linearly with the area enclosed by the interferometer. The use of cold atoms instead of thermal atoms enables miniaturization of Sagnac interferometers without sacrificing large areas. In comparison with thermal beams, slow atoms offer better matching of the initial beam velocity and the velocity with which the matter waves separate. In our case, the area is spanned by a cold atomic beam of 2.79 m s -1 , which is split, deflected and combined by driving a Raman transition between the two hyperfine ground states of 87 Rb in three spatially separated light zones. The use of cold atoms requires a precise angular alignment and high wave front quality of the three independent light zones over the cloud envelope. We present a procedure for mutually aligning the beam splitters at the microradian level by making use of the atom interferometer itself in different configurations. With this method, we currently achieve a sensitivity of 6.1×10 -7 rad s -1 Hz -1/2 . (paper)

HF doppler sounder measurements of the ionospheric signatures of small scale ULF waves

Directory of Open Access Journals (Sweden)

L. J. Baddeley

2005-07-01

Full Text Available An HF Doppler sounder, DOPE (DOppler Pulsation Experiment with three azimuthally-separated propagation paths is used to provide the first statistical examination of small scale-sized, high <i>m> waves where a direct measurement of the azimuthal wavenumber <i>m>, is made in the ionosphere. The study presents 27 events, predominantly in the post-noon sector. The majority of events are Pc4 waves with azimuthal <i>m> numbers ranging from –100 to –200, representing some of the smallest scale waves ever observed in the ionosphere. 4 Pc5 waves are observed in the post-noon sector. The fact that measurements for the wave azimuthal <i>m> number and the wave angular frequency are available allows the drift-bounce resonance condition to be used to hypothesise potential particle populations which could drive the waves through either a drift or drift-bounce resonance interaction mechanism. These results are compared with the statistical study presented by Baddeley et al. (2004 which investigated the statistical likelihood of such driving particle populations occurring in the magnetospheric ring current. The combination of these two studies indicates that any wave which requires a possible drift resonance interaction with particles of energies >60 keV, is statistically unlikely to be generated by such a mechanism. The evidence presented in this paper therefore suggests that in the pre-noon sector the drift-bounce resonance mechanism is statistically more likely implying an anti-symmetric standing wave structure while in the post-noon sector both a drift or drift-bounce resonance interaction is statistically possible, indicating both symmetric and anti-symmetric standing mode structures. A case study is also presented investigating simultaneous observations of a ULF wave in ground magnetometer and DOPE data. The event is in the lower <i>m> range of the statistical study and displays giant pulsation (Pg characteristics.

Keywords

The Virgo gravitational wave interferometer: status and perspectives

CERN Multimedia

CERN. Geneva

2018-01-01

The first recording of a signal from a binary neutron star system by the Advanced LIGO and Advanced Virgo interferometers, and the observation of its remnants by telescopes in all bands of the electromagnetic spectrum, marked the beginning of multimessenger astronomy with gravitational waves. This followed the detection of gravitational wave signals by the LIGO interferometers in 2015, which started the detailed study of highly curved space time. These achievements come after decades of work spent understanding how to measure the tiny space time strain (h ~ 10-21) carried by gravitational waves. In the future, detectors will able to extract much more precise information from these events, or record signals from fainter sources, providing a new view of the Universe. After a presentation of the Virgo interferometer, the main results obtained from binary black hole and neutron star detection are reviewed. The focus will then shift on the perspective offered by a further reduction of noise in ground based interf...

Integrated fiber Michelson interferometer based on poled hollow twin-core fiber.

Science.gov (United States)

Liu, Zhihai; Bo, Fusen; Wang, Lei; Tian, Fengjun; Yuan, Libo

2011-07-01

We propose an integrated fiber Michelson interferometer based on a poled hollow twin-core fiber. The Michelson interferometer can be used as an electro-optic modulator by thermal poling one core of the twin-core fiber and introducing second-order nonlinearity in the fiber. The proposed fiber Michelson interferometer is experimentally demonstrated under driving voltages at the frequency range of 149 to 1000 Hz. The half-wave voltage of the poled fiber is 135 V, and the effective second-order nonlinear coefficient χ² is 1.23 pm/V.

Smart photogalvanic running-grating interferometer

DEFF Research Database (Denmark)

Kukhtarev, N. V.; Kukhtareva, T.; Edwards, M. E.

2005-01-01

Photogalvanic effect produces actuation of periodic motion of macroscopic LiNbO3 crystal. This effect was applied to the development of an all-optical moving-grating interferometer usable for optical trapping and transport of algae chlorella microorganisms diluted in water with a concentration of...

A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber

International Nuclear Information System (INIS)

Frazão, O; Silva, S F; Viegas, J; Baptista, J M; Santos, J L; Roy, P

2010-01-01

A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber is demonstrated. The hybrid interferometer presents three waves. Two parallel Fabry–Perot cavities with low finesse are formed between the splice region and the end of a dual-core microstructured fiber. A Michelson configuration is obtained by the two small cores of the microstructured fiber. The spectral response of the hybrid interferometer presents two pattern fringes with different frequencies due to the respective optical path interferometers. The hybrid interferometer was characterized in strain and temperature presenting different sensitivity coefficients for each topology. Due to these characteristics, this novel sensing head is able to measure strain and temperature, simultaneously

FIR interferometer and scattering measurements of ATF

International Nuclear Information System (INIS)

Ma, C.H.; Hutchinson, D.P.; Fockedey, Y.; Vander Sluis, K.L.; Bennett, C.A.

1989-01-01

A 15-channel far-infrared (FIR) interferometer system has been constructed to measure the electron densities on the ATF plasmas. The system consists of a pair of cw 214-μm difluoromethane (CH 2 F 2 ) lasers, optically pumped by separate CO 2 lasers. The large number of channels is achieved by the use of reflective beam expansion optics to create a beam of 2 cm /times/ 45 cm. After passing through the plasma discharge, the elongated beam produced by the cylindrical mirrors is dissected by an array of 15 off-axis paraboloid reflectors, each of which illuminates a single Schottky-diode detector. The use of the beam expanding optics system reduces the number of optical elements required for the interferometer to approximately 2-3 per channel. The FIR laser beams are transported from the laser room to the experimental area by 25 mm i.d. dielectric waveguides purged with dry nitrogen. The system can also be operated at a wavelength of 119-μm by changing the gas in FIR laser cavities to methanol for high density experiments. Details of the system are described. A study is underway to determine the optimum design of a FIR scattering system for the ATF. This scattering system will be used to investigate density fluctuations with scale lengths from 0.1 cm to the plasma radius. The laser for this scattering system may be operated at wavelengths of 447, 307, 214, 184, and 119 μm with power levels of 100 to 500 mW. A summary of the study is presented. 6 refs., 1 fig

Semiconductor laser shearing interferometer

International Nuclear Information System (INIS)

Ming Hai; Li Ming; Chen Nong; Xie Jiaping

1988-03-01

The application of semiconductor laser on grating shearing interferometry is studied experimentally in the present paper. The method measuring the coherence of semiconductor laser beam by ion etching double frequency grating is proposed. The experimental result of lens aberration with semiconductor laser shearing interferometer is given. Talbot shearing interferometry of semiconductor laser is also described. (author). 2 refs, 9 figs

Torpedo and countermeasures modelling in the Torpedo Defence System Testbed

NARCIS (Netherlands)

Benders, F.P.A.; Witberg, R.R.; H.J. Grootendorst, H.J.

2002-01-01

Several years ago, TNO-FEL started the development of the Torpedo Defence System Testbed (TDSTB) based on the TORpedo SIMulation (TORSIM) model and the Maritime Operations Simulation and Evaluation System (MOSES). MOSES provides the simulation and modelling environment for the evaluation and

Miniaturized fiber in-line interferometer fabricated by femtosecond laser micromachining

International Nuclear Information System (INIS)

Wang, D.N.; Ying Wang

2010-01-01

Complete text of publication follows. An in-line fiber MZI is attractive due to its simplicity and compactness. Various types of in-line fiber MZI structures have been developed, based on interference between the fundamental core mode and the higher order cladding mode, with size of typically in the order of millimeters or centimeters, and have very small effective refractive index (RI) difference between the core mode and the cladding mode ( in1 and I in2 . While I in1 remains traveling along the fiber core, I in2 has to propagate through the micro-cavity, and the interference happens when the two output beams recombine at the fiber core. The essential difference between our MZI and those reported previously lies in the fact that our device is based on the interference of the guided mode in the core and the unguided mode travelling through the micro-cavity. The RI difference between the two arms of the MZI is very large (> 0.10), which allows a dramatic reduction of the cavity length while maintaining a high RI sensitivity. Moreover, the position of the RI change can be precisely located due to the small size of the micro-cavity. The interferometer created in this work exhibits a high RI sensitivity, ∼ -9370 nm/RIU (refractive index unit) within the RI range between 1.31 and 1.335. Moreover, a precise sensing location can be ensured owing to the small size of the interferometer. Such a fiber device has high potential in chemical and biological sensor applications. Acknowledgement. This work was supported by Hong Kong SAR government through a GRF (general research fund) grant PolyU 5306/08E and The Hong Kong Polytechnic University Research Grant A-SA52.

Reducing tilt-to-length coupling for the LISA test mass interferometer

Science.gov (United States)

Tröbs, M.; Schuster, S.; Lieser, M.; Zwetz, M.; Chwalla, M.; Danzmann, K.; Fernández Barránco, G.; Fitzsimons, E. D.; Gerberding, O.; Heinzel, G.; Killow, C. J.; Perreur-Lloyd, M.; Robertson, D. I.; Schwarze, T. S.; Wanner, G.; Ward, H.

2018-05-01

Objects sensed by laser interferometers are usually not stable in position or orientation. This angular instability can lead to a coupling of angular tilt to apparent longitudinal displacement—tilt-to-length coupling (TTL). In LISA this is a potential noise source for both the test mass interferometer and the long-arm interferometer. We have experimentally investigated TTL coupling in a setup representative for the LISA test mass interferometer and used this system to characterise two different imaging systems (a two-lens design and a four-lens design) both designed to minimise TTL coupling. We show that both imaging systems meet the LISA requirement of  ±25 μm rad‑1 for interfering beams with relative angles of up to  ±300 μrad. Furthermore, we found a dependency of the TTL coupling on beam properties such as the waist size and location, which we characterised both theoretically and experimentally.

James Webb Space Telescope Optical Simulation Testbed: Segmented Mirror Phase Retrieval Testing

Science.gov (United States)

Laginja, Iva; Egron, Sylvain; Brady, Greg; Soummer, Remi; Lajoie, Charles-Philippe; Bonnefois, Aurélie; Long, Joseph; Michau, Vincent; Choquet, Elodie; Ferrari, Marc; Leboulleux, Lucie; Mazoyer, Johan; N’Diaye, Mamadou; Perrin, Marshall; Petrone, Peter; Pueyo, Laurent; Sivaramakrishnan, Anand

2018-01-01

The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a hardware simulator designed to produce JWST-like images. A model of the JWST three mirror anastigmat is realized with three lenses in form of a Cooke Triplet, which provides JWST-like optical quality over a field equivalent to a NIRCam module, and an Iris AO segmented mirror with hexagonal elements is standing in for the JWST segmented primary. This setup successfully produces images extremely similar to NIRCam images from cryotesting in terms of the PSF morphology and sampling relative to the diffraction limit.The testbed is used for staff training of the wavefront sensing and control (WFS&C) team and for independent analysis of WFS&C scenarios of the JWST. Algorithms like geometric phase retrieval (GPR) that may be used in flight and potential upgrades to JWST WFS&C will be explored. We report on the current status of the testbed after alignment, implementation of the segmented mirror, and testing of phase retrieval techniques.This optical bench complements other work at the Makidon laboratory at the Space Telescope Science Institute, including the investigation of coronagraphy for segmented aperture telescopes. Beyond JWST we intend to use JOST for WFS&C studies for future large segmented space telescopes such as LUVOIR.

Analysis, modeling, and simulation (AMS) testbed development and evaluation to support dynamic mobility applications (DMA) and active transportation and demand management (ATDM) programs : Dallas testbed analysis plan.

Science.gov (United States)

2016-06-16

The primary objective of this project is to develop multiple simulation Testbeds/transportation models to evaluate theimpacts of DMA connected vehicle applications and the active and dynamic transportation management (ATDM)strategies. The outputs (mo...

Vibration compensated high-resolution scanning white-light Linnik-interferometer

Science.gov (United States)

Tereschenko, Stanislav; Lehmann, Peter; Gollor, Pascal; Kuehnhold, Peter

2017-06-01

We present a high-resolution Linnik scanning white-light interferometer (SWLI) with integrated distance measuring interferometer (DMI) for close-to-machine applications in the presence of environmental vibrations. The distance, measured by DMI during the depth-scan, is used for vibration compensation of SWLI signals. The reconstruction of the white-light interference signals takes place after measurement by reordering the captured images in accordance with their real positions obtained by the DMI and subsequent trigonometrical approximation. This system is the further development of our previously presented Michelson-interferometer. We are able to compensate for arbitrary vibrations with frequencies up to several kilohertz and amplitudes in the lower micrometer range. Completely distorted SWLI signals can be reconstructed and the surface topography can be obtained with high accuracy. We demonstrate the feasibility of the method by examples of practical measurements with and without vibrational disturbances.

Design of a Michelson Interferometer for Quantitative Refraction Index Profile Measurements

NARCIS (Netherlands)

Nijholt, J.L.M.

1998-01-01

This book describes the theoretical design of a three camera Michelson interferometer set-up for quantitative refractive index measuerments. Although a two camera system is easier to align and less expensive, a three camera interferometer is preferred because the expected measuring accuracy is much

Sagnac interferometer as a speed-meter-type, quantum-nondemolition gravitational-wave detector

International Nuclear Information System (INIS)

Chen Yanbei

2003-01-01

According to quantum measurement theory, 'speed meters' - devices that measure the momentum, or speed, of free test masses - are immune to the standard quantum limit (SQL). It is shown that a Sagnac-interferometer gravitational-wave detector is a speed meter and therefore in principle it can beat the SQL by large amounts over a wide band of frequencies. It is shown, further, that, when one ignores optical losses, a signal-recycled Sag nac interferometer with Fabry-Perot arm cavities has precisely the same performance, for the same circulating light power, as the Michelson speed-meter interferometer recently invented and studied by Purdue and the author. The influence of optical losses is not studied, but it is plausible that they be fairly unimportant for the Sag nac interferometer, as for other speed meters. With squeezed vacuum (squeeze factor e -2R =0.1) injected into its dark port, the recycled Sag nac interferometer can beat the SQL by a factor √(10)≅3 over the frequency band 10 Hz c ∼820 kw as is to be used by the (quantum limited) second-generation Advanced LIGO interferometers--if other noise sources are made sufficiently small. It is concluded that the Sag nac optical configuration, with signal recycling and squeezed-vacuum injection, is an attractive candidate for third-generation interferometric gravitational-wave detectors (LIGO-III and EURO)

The JPSS CrIS Instrument and the Evolution of Space-Based Infrared Sounders

Science.gov (United States)

Glumb, Ronald; Suwinski, Lawrence; Wells, Steven; Glumb, Anna; Malloy, Rebecca; Colton, Marie

2018-01-01

This paper will summarize the development of infrared sounders since the 1970s, describe the technological hurdles that were overcome to provide ever-increasing performance capabilities, and highlight the radiometric performance of the CrIS instrument on JPSS-1 (CrIS-JPSS1). This includes details of the CrIS-JPSS1 measured noise-equivalent spectral radiance (NEdN) performance, radiometric uncertainty performance utilizing a new and improved internal calibration target, short-term and long-term repeatability, spectral uncertainty, and spectral stability. In addition, the full-resolution operating modes for CrIS-JPSS1 will be reviewed, including a discussion of how these modes will be used during on-orbit characterization tests. We will provide a brief update of CrIS-SNPP on-obit performance and the production status of the CrIS instruments for JPSS-2 through JPSS-4. Current technological challenges will also be reviewed, including how ongoing research and development is enabling improvements to future sounders. The expanding usage of infrared sounding data will also be discussed, including demonstration of value via data assimilation, the roles of the public/private sector in communicating the importance of sounding data for long-term observations, and the long road to success from research to operational data products.

Design and fabrication of a high-damage threshold infrared Smattt interferometer

International Nuclear Information System (INIS)

Hammond, R.B.; Gibbs, A.J.

1981-01-01

It has been shown that a Smartt interferometer may be used as a very precise alignment tool for infrared lasers. This interferometer may also be used effectively to investigate the phase front of a laser pulse. To use this tool for applications to high-power, fast-pulse laser systems such as Helios and Antares; however, it has been necessary to fabricate a structure with the unique optical characteristics of the Smartt interferometer combined with a very high optical-damage threshold. We have been successful in this effort by utilizing the high technology, process control, and unique properties of semiconductor-grade, single-crystal Si

Evaluation of Unmanned Aircraft Systems (UAS) for Weather and Climate using the Multi-testbed approach

Science.gov (United States)

Baker, B.; Lee, T.; Buban, M.; Dumas, E. J.

2017-12-01

Evaluation of Unmanned Aircraft Systems (UAS) for Weather and Climate using the Multi-testbed approachC. Bruce Baker1, Ed Dumas1,2, Temple Lee1,2, Michael Buban1,21NOAA ARL, Atmospheric Turbulence and Diffusion Division, Oak Ridge, TN2Oak Ridge Associated Universities, Oak Ridge, TN The development of a small Unmanned Aerial System (sUAS) testbeds that can be used to validate, integrate, calibrate and evaluate new technology and sensors for routine boundary layer research, validation of operational weather models, improvement of model parameterizations, and recording observations within high-impact storms is important for understanding the importance and impact of using sUAS's routinely as a new observing platform. The goal of the multi-testbed approach is to build a robust set of protocols to assess the cost and operational feasibility of unmanned observations for routine applications using various combinations of sUAS aircraft and sensors in different locations and field experiments. All of these observational testbeds serve different community needs, but they also use a diverse suite of methodologies for calibration and evaluation of different sensors and platforms for severe weather and boundary layer research. The primary focus will be to evaluate meteorological sensor payloads to measure thermodynamic parameters and define surface characteristics with visible, IR, and multi-spectral cameras. This evaluation will lead to recommendations for sensor payloads for VTOL and fixed-wing sUAS.

Atomic interferometry: construction, characterisation and optimisation of an interferometer. Application to precision measurements

International Nuclear Information System (INIS)

Buechner, Matthias

2010-01-01

This manuscript describes my research activity in atom interferometry. As an introduction to this domain, we have first described some atom interferometers and their applications. We then describe the atom interferometer we have developed in Toulouse. This is a Mach-Zehnder atom interferometer; the atom source is a thermal supersonic lithium beam and atom manipulation is based on laser diffraction in the Bragg regime. This two interferometer arms are spatially separated, with a maximum distance near 100 μm. The interferometer performances are excellent, with a fringe visibility as large as 84.5 % and a high output flux, thus providing a phase sensitivity of 15 mrad √(Hz). We have used this interferometer for several experiments, with a perturbation applied on only one interferometer arm. When the perturbation is an electric field, we thus measure the electric polarizability of lithium, with an uncertainty 3 times smaller than the best previous measurement. When the perturbation is a gas at low density, we measure the complex refraction index of this gas for lithium atomic waves. If the perturbation is a nano-grating, we measure the complex amplitude of the diffraction zeroth order and this amplitude is very sensitive to the van der Waals interaction of the lithium atom with the nano-grating surface. An important part of this manuscript concerns further developments of our activity. We discuss several improvements of the measurement of the electric polarizability of lithium atom and we hope to access to a precision comparable to the one of the best ab initio calculations of this quantity. We plan to detect a new topological phase, predicted by theory in 1993 but never observed. Finally, we are starting the construction of a second generation atom interferometer, with a slow and intense lithium beam. This new source will give a larger signal and a longer interaction time, thus enabling the detection of considerably weaker perturbations: a fascinating possibility

Cloud and Thermodynamic Parameters Retrieved from Satellite Ultraspectral Infrared Measurements

Science.gov (United States)

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

2008-01-01

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

Plasma electron density measurement with multichannel microwave interferometer on the HL-1 tokamak device

International Nuclear Information System (INIS)

Xu Deming; Zhang Hongyin; Liu Zetian; Ding Xuantong; Li Qirui; Wen Yangxi

1989-11-01

A multichannel microwave interferometer which is composed of different microwave interferometers (one 2 mm band, one 4 mm band and two 8 mm band) has been used to measure the plasma electron density on HL-1 tokamak device. The electron density approaching to 5 x 10 13 cm -3 is measured by a 2 mm band microwave interferometer. In the determinable range, the electron density profile in the cross-section on HL-1 device has been measured by this interferometer. A microcomputer data processing system is also developed

Sensitivity of a fibre scattered-light interferometer to external phase perturbations in an optical fibre

Energy Technology Data Exchange (ETDEWEB)

Alekseev, A E; Potapov, V T [V.A.Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Fryazino Branch, Fryazino, Moscow region (Russian Federation); Gorshkov, B G [OOO ' Petrofaiber' , Russia, Tula region, Novomoskovsk (Russian Federation)

2015-10-31

Sensitivity of a fibre scattered-light interferometer to external phase perturbations is studied for the first time. An expression is derived for an average power of a useful signal at the interferometer output under external harmonic perturbations in a signal fibre of the interferometer. It is shown that the maximum sensitivity of the scattered-light interferometer depends on the dispersion of the interferogram intensity. An average signal-to-noise ratio is determined theoretically and experimentally at the output of the interferometer at different amplitudes of external perturbations. Using the measured dependences of the signal-to-noise ratio, the threshold sensitivity of the fibre scattered-light interferometer to external phase perturbations is found. The results obtained can be used to optimise characteristics of optical time-domain reflectometers and to design individual phase-sensitive fibre-optic sensors. (laser applications and other topics in quantum electronics)

Large Scale Data Mining to Improve Usability of Data: An Intelligent Archive Testbed

Science.gov (United States)

Ramapriyan, Hampapuram; Isaac, David; Yang, Wenli; Morse, Steve

2005-01-01

Research in certain scientific disciplines - including Earth science, particle physics, and astrophysics - continually faces the challenge that the volume of data needed to perform valid scientific research can at times overwhelm even a sizable research community. The desire to improve utilization of this data gave rise to the Intelligent Archives project, which seeks to make data archives active participants in a knowledge building system capable of discovering events or patterns that represent new information or knowledge. Data mining can automatically discover patterns and events, but it is generally viewed as unsuited for large-scale use in disciplines like Earth science that routinely involve very high data volumes. Dozens of research projects have shown promising uses of data mining in Earth science, but all of these are based on experiments with data subsets of a few gigabytes or less, rather than the terabytes or petabytes typically encountered in operational systems. To bridge this gap, the Intelligent Archives project is establishing a testbed with the goal of demonstrating the use of data mining techniques in an operationally-relevant environment. This paper discusses the goals of the testbed and the design choices surrounding critical issues that arose during testbed implementation.

Michelson interferometer based interleaver design using classic IIR filter decomposition.

Science.gov (United States)

Cheng, Chi-Hao; Tang, Shasha

2013-12-16

An elegant method to design a Michelson interferometer based interleaver using a classic infinite impulse response (IIR) filter such as Butterworth, Chebyshev, and elliptic filters as a starting point are presented. The proposed design method allows engineers to design a Michelson interferometer based interleaver from specifications seamlessly. Simulation results are presented to demonstrate the validity of the proposed design method.

ESP (External-Stores Program) - A Pilot Computer Program for Determining Flutter-Critical External-Store Configurations. Volume 1. User’s Manual,

Science.gov (United States)

1985-02-01

li’Lii El. IE F INE ,UT 1 = K MM. * GET, NAST484/UN=SYSTEM. E(EGIN, ,NAST464. PFL, 160000, RED’UCE(-). LINKI , L~DDEDDD Figure A-I1 Typical Control-Card...initiated via Che LINKI statement, in which the second term is the input data file. The permanent file name KMDM, shown in conjunction with local file

Satellite Sounder Observations of Contrasting Tropospheric Moisture Transport Regimes: Saharan Air Layers, Hadley Cells, and Atmospheric Rivers

Energy Technology Data Exchange (ETDEWEB)

Nalli, Nicholas R.; Barnet, Christopher D.; Reale, Tony; Liu, Quanhua; Morris, Vernon R.; Spackman, J. Ryan; Joseph, Everette; Tan, Changyi; Sun, Bomin; Tilley, Frank; Leung, L. Ruby; Wolfe, Daniel

2016-12-01

This paper examines the performance of satellite sounder atmospheric vertical moisture proles (AVMP) under tropospheric conditions encompassing moisture contrasts driven by convection and advection transport mechanisms, specifically Atlantic Ocean Saharan air layers (SALs) and Pacific Ocean moisture conveyer belts (MCBs) commonly referred to as atmospheric rivers (ARs), both of these being mesoscale to synoptic meteorological phenomena within the vicinity of subtropical Hadley subsidence zones. Operational AVMP environmental data records retrieved from the Suomi National Polar-orbiting Partnership (SNPP) NOAA-Unique Combined Atmospheric Processing System (NUCAPS) are collocated with dedicated radiosonde observations (RAOBs) obtained from ocean-based intensive field campaigns; these RAOBs provide uniquely independent correlative truth data not assimilated into numerical weather prediction models for satellite sounder validation over open ocean. Using these marine-based data, we empirically assess the performance of the operational NUCAPS AVMP product for detecting and resolving these tropospheric moisture features over otherwise RAOB-sparse regions.

Compact all-fiber interferometer system for shock acceleration measurement

Science.gov (United States)

Zhao, Jiang; Pi, Shaohua; Hong, Guangwei; Zhao, Dong; Jia, Bo

2013-08-01

Acceleration measurement plays an important role in a variety of fields in science and engineering. In particular, the accurate, continuous and non-contact recording of the shock acceleration profiles of the free target surfaces is considered as a critical technique in shock physics. Various kinds of optical interferometers have been developed to monitor the motion of the surfaces of shocked targets since the 1960s, for instance, the velocity interferometer system for any reflector, the fiber optic accelerometer, the photonic Doppler velocimetry system and the displacement interferometer. However, most of such systems rely on the coherent quasi-monochromatic illumination and discrete optic elements, which are costly in setting-up and maintenance. In 1996, L. Levin et al reported an interferometric fiber-optic Doppler velocimeter with high-dynamic range, in which fiber-coupled components were used to replace the discrete optic elements. However, the fringe visibility of the Levin's system is low because of the coupled components, which greatly limits the reliability and accuracy in the shock measurement. In this paper, a compact all-fiber interferometer system for measuring the shock acceleration is developed and tested. The advantage of the system is that not only removes the non-interfering light and enhances the fringe visibility, but also reduces polarization induced signal fading and the polarization induced phase shift. Moreover, it also does not require a source of long coherence length. The system bases entirely on single-mode fiber optics and mainly consists of a polarization beam splitter, a faraday rotator, a depolarizer and a 3×3 single-mode fiber coupler which work at 1310 nm wavelength. The optical systems of the interferometer are described and the experimental results compared with a shock acceleration calibration system with a pneumatic exciter (PneuShockTM Model 9525C by The Modal Shop) are reported. In the shock acceleration test, the

Mach-Zehnder atom interferometer inside an optical fiber

Science.gov (United States)

Xin, Mingjie; Leong, Wuiseng; Chen, Zilong; Lan, Shau-Yu

2017-04-01

Precision measurement with light-pulse grating atom interferometry in free space have been used in the study of fundamental physics and applications in inertial sensing. Recent development of photonic band-gap fibers allows light for traveling in hollow region while preserving its fundamental Gaussian mode. The fibers could provide a very promising platform to transfer cold atoms. Optically guided matter waves inside a hollow-core photonic band-gap fiber can mitigate diffraction limit problem and has the potential to bring research in the field of atomic sensing and precision measurement to the next level of compactness and accuracy. Here, we will show our experimental progress towards an atom interferometer in optical fibers. We designed an atom trapping scheme inside a hollow-core photonic band-gap fiber to create an optical guided matter waves system, and studied the coherence properties of Rubidium atoms in this optical guided system. We also demonstrate a Mach-Zehnder atom interferometer in the optical waveguide. This interferometer is promising for precision measurements and designs of mobile atomic sensors.

Analysis of threshold curves for superconducting interferometers

International Nuclear Information System (INIS)

Peterson, R.L.; Hamilton, C.A.

1979-01-01

Threshold curves for multijunction superconducting interferometers have been calculated previously, showing general agreement with observed features, especially in symmetric cases. We here add some more details to the analysis, paying particular attention to the effects of asymmetries in coupling, inductance, or critical currents. Feed-loop inductance and flux quantization in the feed loop can be important. A changing lobe pattern over many periods, asymmetries within a period, shifting patterns between runs spanning a warm-up, and sudden changes in pattern because of noise in the environment are all quantitatively explainable on the basis of this model. By use of a single ''calibration curve'', the inductance for symmetric two- or three-junction interferometers can be obtained immediately

Interpreting Observations of Large-Scale Traveling Ionospheric Disturbances by Ionospheric Sounders

Science.gov (United States)

Pederick, L. H.; Cervera, M. A.; Harris, T. J.

2017-12-01

From July to October 2015, the Australian Defence Science and Technology Group conducted an experiment during which a vertical incidence sounder (VIS) was set up at Alice Springs Airport. During September 2015 this VIS observed the passage of many large-scale traveling ionospheric disturbances (TIDs). By plotting the measured virtual heights across multiple frequencies as a function of time, the passage of the TID can be clearly displayed. Using this plotting method, we show that all the TIDs observed during the campaign by the VIS at Alice Springs show an apparent downward phase progression of the crests and troughs. The passage of the TID can be more clearly interpreted by plotting the true height of iso-ionic contours across multiple plasma frequencies; the true heights can be obtained by inverting each ionogram to obtain an electron density profile. These plots can be used to measure the vertical phase speed of a TID and also reveal a time lag between events seen in true height compared to virtual height. To the best of our knowledge, this style of analysis has not previously been applied to other swept-frequency sounder observations. We develop a simple model to investigate the effect of the passage of a large-scale TID on a VIS. The model confirms that for a TID with a downward vertical phase progression, the crests and troughs will appear earlier in virtual height than in true height and will have a smaller apparent speed in true height than in virtual height.

Potentiality of an orbiting interferometer for space-time experiments

International Nuclear Information System (INIS)

Grassi Strini, A.M.; Strini, G.; Tagliaferri, G.

1979-01-01

It is suggested that by putting a Michelson interferometer aboard a spacecraft orbiting around the earth, very substantial progress could be made in space-time experiments. It is estimated that in measurements of e.g. some anisotropy of the light velocity, a spacecraft-borne interferometer of quite small size (0.1 m arm-length) would reach a sensitivity greater by a factor of approximately 10 8 than the best achievements to date of ground-based devices. (author)

System analysis of a tilted field-widened Michelson interferometer for high spectral resolution lidar.

Science.gov (United States)

Liu, Dong; Hostetler, Chris; Miller, Ian; Cook, Anthony; Hair, Johnathan

2012-01-16

High spectral resolution lidars (HSRLs) have shown great value in aircraft aerosol remote sensing application and are planned for future satellite missions. A compact, robust, quasi-monolithic tilted field-widened Michelson interferometer is being developed as the spectral discrimination filter for an second-generation HSRL(HSRL-2) at NASA Langley Research Center. The Michelson interferometer consists of a cubic beam splitter, a solid arm and an air arm. Piezo stacks connect the air arm mirror to the body of the interferometer and can tune the interferometer within a small range. The whole interferometer is tilted so that the standard Michelson output and the reflected complementary output can both be obtained. In this paper, the transmission ratio is proposed to evaluate the performance of the spectral filter for HSRL. The transmission ratios over different types of system imperfections, such as cumulative wavefront error, locking error, reflectance of the beam splitter and anti-reflection coatings, system tilt, and depolarization angle are analyzed. The requirements of each imperfection for good interferometer performance are obtained.

Conceptual Design and Cost Estimate of a Subsonic NASA Testbed Vehicle (NTV) for Aeronautics Research

Science.gov (United States)

Nickol, Craig L.; Frederic, Peter

2013-01-01

A conceptual design and cost estimate for a subsonic flight research vehicle designed to support NASA's Environmentally Responsible Aviation (ERA) project goals is presented. To investigate the technical and economic feasibility of modifying an existing aircraft, a highly modified Boeing 717 was developed for maturation of technologies supporting the three ERA project goals of reduced fuel burn, noise, and emissions. This modified 717 utilizes midfuselage mounted modern high bypass ratio engines in conjunction with engine exhaust shielding structures to provide a low noise testbed. The testbed also integrates a natural laminar flow wing section and active flow control for the vertical tail. An eight year program plan was created to incrementally modify and test the vehicle, enabling the suite of technology benefits to be isolated and quantified. Based on the conceptual design and programmatic plan for this testbed vehicle, a full cost estimate of $526M was developed, representing then-year dollars at a 50% confidence level.

Software Testbed for Developing and Evaluating Integrated Autonomous Subsystems

Science.gov (United States)

Ong, James; Remolina, Emilio; Prompt, Axel; Robinson, Peter; Sweet, Adam; Nishikawa, David

2015-01-01

To implement fault tolerant autonomy in future space systems, it will be necessary to integrate planning, adaptive control, and state estimation subsystems. However, integrating these subsystems is difficult, time-consuming, and error-prone. This paper describes Intelliface/ADAPT, a software testbed that helps researchers develop and test alternative strategies for integrating planning, execution, and diagnosis subsystems more quickly and easily. The testbed's architecture, graphical data displays, and implementations of the integrated subsystems support easy plug and play of alternate components to support research and development in fault-tolerant control of autonomous vehicles and operations support systems. Intelliface/ADAPT controls NASA's Advanced Diagnostics and Prognostics Testbed (ADAPT), which comprises batteries, electrical loads (fans, pumps, and lights), relays, circuit breakers, invertors, and sensors. During plan execution, an experimentor can inject faults into the ADAPT testbed by tripping circuit breakers, changing fan speed settings, and closing valves to restrict fluid flow. The diagnostic subsystem, based on NASA's Hybrid Diagnosis Engine (HyDE), detects and isolates these faults to determine the new state of the plant, ADAPT. Intelliface/ADAPT then updates its model of the ADAPT system's resources and determines whether the current plan can be executed using the reduced resources. If not, the planning subsystem generates a new plan that reschedules tasks, reconfigures ADAPT, and reassigns the use of ADAPT resources as needed to work around the fault. The resource model, planning domain model, and planning goals are expressed using NASA's Action Notation Modeling Language (ANML). Parts of the ANML model are generated automatically, and other parts are constructed by hand using the Planning Model Integrated Development Environment, a visual Eclipse-based IDE that accelerates ANML model development. Because native ANML planners are currently

Plasma measurement by feedback-stabilized dual-beam laser interferometer

International Nuclear Information System (INIS)

Yasuda, Akio; Kawahata, Kazuo; Kanai, Yasubumi.

1982-03-01

The plasma density in a dynamic magneto arcjet is measured by a stabilized dual-beam laser interferometer proposed by the authors. The fringe shift for a 0.63 μm beam of He-Ne laser is used to stabilize the interferometer against the effect of mechanical vibration by means of a feedback controlled speaker coil, while the other beam of 3.39 μm, for which the effect of mechanical vibrations is excluded, is used to measure plasma density. Stability of --1/500 of one fringe for 0.63 μm is obtained during a long period for frequencies lower than a few Hertz. Stability for higher frequencies, which determines the accuracy of the present measurement, is limited to --1/30 of one fringe for 0.63 μm, which corresponds to --1/200 of one fringe and a line electron density of --1.5 x 10 14 cm - 2 for 3.39 μm, by acoustic noise picked up by the speaker coil. The advantage of this technique over the single-laser technique is that the frequency response of the interferometer extends down to zero frequency. Since the effect of the neutral gas background is practically reduced to zero, the present interferometer is to be applied advantageously to the diagnostics of the plasma produced in high pressure gases. (author)

Distributed computing testbed for a remote experimental environment

International Nuclear Information System (INIS)

Butner, D.N.; Casper, T.A.; Howard, B.C.; Henline, P.A.; Davis, S.L.; Barnes, D.

1995-01-01

Collaboration is increasing as physics research becomes concentrated on a few large, expensive facilities, particularly in magnetic fusion energy research, with national and international participation. These facilities are designed for steady state operation and interactive, real-time experimentation. We are developing tools to provide for the establishment of geographically distant centers for interactive operations; such centers would allow scientists to participate in experiments from their home institutions. A testbed is being developed for a Remote Experimental Environment (REE), a ''Collaboratory.'' The testbed will be used to evaluate the ability of a remotely located group of scientists to conduct research on the DIII-D Tokamak at General Atomics. The REE will serve as a testing environment for advanced control and collaboration concepts applicable to future experiments. Process-to-process communications over high speed wide area networks provide real-time synchronization and exchange of data among multiple computer networks, while the ability to conduct research is enhanced by adding audio/video communication capabilities. The Open Software Foundation's Distributed Computing Environment is being used to test concepts in distributed control, security, naming, remote procedure calls and distributed file access using the Distributed File Services. We are exploring the technology and sociology of remotely participating in the operation of a large scale experimental facility

Inspection of commercial optical devices for data storage using a three Gaussian beam microscope interferometer

International Nuclear Information System (INIS)

Flores, J. Mauricio; Cywiak, Moises; Servin, Manuel; Juarez P, Lorenzo

2008-01-01

Recently, an interferometric profilometer based on the heterodyning of three Gaussian beams has been reported. This microscope interferometer, called a three Gaussian beam interferometer, has been used to profile high quality optical surfaces that exhibit constant reflectivity with high vertical resolution and lateral resolution near λ. We report the use of this interferometer to measure the profiles of two commercially available optical surfaces for data storage, namely, the compact disk (CD-R) and the digital versatile disk (DVD-R). We include experimental results from a one-dimensional radial scan of these devices without data marks. The measurements are taken by placing the devices with the polycarbonate surface facing the probe beam of the interferometer. This microscope interferometer is unique when compared with other optical measuring instruments because it uses narrowband detection, filters out undesirable noisy signals, and because the amplitude of the output voltage signal is basically proportional to the local vertical height of the surface under test, thus detecting with high sensitivity. We show that the resulting profiles, measured with this interferometer across the polycarbonate layer, provide valuable information about the track profiles, making this interferometer a suitable tool for quality control of surface storage devices

Sagnac Interferometer Based Generation of Controllable Cylindrical Vector Beams

Directory of Open Access Journals (Sweden)

Cristian Acevedo

2016-01-01

Full Text Available We report on a novel experimental geometry to generate cylindrical vector beams in a very robust manner. Continuous control of beams’ properties is obtained using an optically addressable spatial light modulator incorporated into a Sagnac interferometer. Forked computer-generated holograms allow introducing different topological charges while orthogonally polarized beams within the interferometer permit encoding the spatial distribution of polarization. We also demonstrate the generation of complex waveforms obtained by combining two orthogonal beams having both radial modulations and azimuthal dislocations.

Design of an optical spatial interferometer with transformation optics

International Nuclear Information System (INIS)

Naghibi, Atefeh; Shokooh-Saremi, Mehrdad

2015-01-01

In this paper, we apply transformation optics to design an optical spatial interferometer. The transformation equations are described and two-dimensional finite element simulations are presented to numerically confirm the functionality of the device. It is shown that a small change in the refractive index can alter the interference pattern and hence can be detected. The design of the interferometer could expand transformation optics’ applications and make way for introduction of new structures with unique electromagnetic or optical functionalities. (paper)

Power-recycled michelson interferometer with a 50/50 grating beam splitter

International Nuclear Information System (INIS)

Friedrich, D; Burmeister, O; Britzger, M; Bunkowski, A; Danzmann, K; Schnabel, R; Clausnitzer, T; Fahr, S; Kley, E-B; Tuennermann, A

2008-01-01

We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about F PR ∼ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed

Power-recycled michelson interferometer with a 50/50 grating beam splitter

OpenAIRE

Friedrich, Daniel; Burmeister, O.; Britzger, M.; Bunkowski, A.; Clausnitzer, T.; Fahr, S.; Kley, E.B.; Tünnermann, A.; Danzmann, Karsten; Schnabel, Roman

2008-01-01

We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about FPR ≈ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed.

Improved density measurement by FIR laser interferometer on EAST tokamak

Energy Technology Data Exchange (ETDEWEB)

Shen, Jie, E-mail: shenjie1988@ipp.ac.cn; Jie, Yinxian; Liu, Haiqing; Wei, Xuechao; Wang, Zhengxing; Gao, Xiang

2013-11-15

Highlights: • In 2012, the water-cooling Mo wall was installed in EAST. • A schottky barrier diode detector is designed and used on EAST for the first time. • The three-channel far-infrared laser interferometer can measure the electron density. • The improved measurement and latest experiment results are reported. • The signal we get in this experiment campaign is much better than we got in 2010. -- Abstract: A three-channel far-infrared (FIR) hydrogen cyanide (HCN) laser interferometer is in operation since 2010 to measure the line averaged electron density on experimental advanced superconducting tokamak (EAST). The HCN laser signal is improved by means of a new schottky barrier diode (SBD) detector. The improved measurement and latest experiment results of the three-channel FIR laser interferometer on EAST tokamak are reported.

Improved density measurement by FIR laser interferometer on EAST tokamak

International Nuclear Information System (INIS)

Shen, Jie; Jie, Yinxian; Liu, Haiqing; Wei, Xuechao; Wang, Zhengxing; Gao, Xiang

2013-01-01

Highlights: • In 2012, the water-cooling Mo wall was installed in EAST. • A schottky barrier diode detector is designed and used on EAST for the first time. • The three-channel far-infrared laser interferometer can measure the electron density. • The improved measurement and latest experiment results are reported. • The signal we get in this experiment campaign is much better than we got in 2010. -- Abstract: A three-channel far-infrared (FIR) hydrogen cyanide (HCN) laser interferometer is in operation since 2010 to measure the line averaged electron density on experimental advanced superconducting tokamak (EAST). The HCN laser signal is improved by means of a new schottky barrier diode (SBD) detector. The improved measurement and latest experiment results of the three-channel FIR laser interferometer on EAST tokamak are reported

Noise performance of microwave humidity sounders over their lifetime

Science.gov (United States)

Hans, Imke; Burgdorf, Martin; John, Viju O.; Mittaz, Jonathan; Buehler, Stefan A.

2017-12-01

The microwave humidity sounders Special Sensor Microwave Water Vapor Profiler (SSMT-2), Advanced Microwave Sounding Unit-B (AMSU-B) and Microwave Humidity Sounder (MHS) to date have been providing data records for 25 years. So far, the data records lack uncertainty information essential for constructing consistent long time data series. In this study, we assess the quality of the recorded data with respect to the uncertainty caused by noise. We calculate the noise on the raw calibration counts from the deep space views (DSVs) of the instrument and the noise equivalent differential temperature (NEΔT) as a measure for the radiometer sensitivity. For this purpose, we use the Allan deviation that is not biased from an underlying varying mean of the data and that has been suggested only recently for application in atmospheric remote sensing. Moreover, we use the bias function related to the Allan deviation to infer the underlying spectrum of the noise. As examples, we investigate the noise spectrum in flight for some instruments. For the assessment of the noise evolution in time, we provide a descriptive and graphical overview of the calculated NEΔT over the life span of each instrument and channel. This overview can serve as an easily accessible information for users interested in the noise performance of a specific instrument, channel and time. Within the time evolution of the noise, we identify periods of instrumental degradation, which manifest themselves in an increasing NEΔT, and periods of erratic behaviour, which show sudden increases of NEΔT interrupting the overall smooth evolution of the noise. From this assessment and subsequent exclusion of the aforementioned periods, we present a chart showing available data records with NEΔT processing to provide input values for the uncertainty propagation in the generation of a new set of Fundamental Climate Data Records (FCDRs) that are currently produced in the project Fidelity and Uncertainty in Climate data

Solar Resource Assessment with Sky Imagery and a Virtual Testbed for Sky Imager Solar Forecasting

Science.gov (United States)

Kurtz, Benjamin Bernard

In recent years, ground-based sky imagers have emerged as a promising tool for forecasting solar energy on short time scales (0 to 30 minutes ahead). Following the development of sky imager hardware and algorithms at UC San Diego, we present three new or improved algorithms for sky imager forecasting and forecast evaluation. First, we present an algorithm for measuring irradiance with a sky imager. Sky imager forecasts are often used in conjunction with other instruments for measuring irradiance, so this has the potential to decrease instrumentation costs and logistical complexity. In particular, the forecast algorithm itself often relies on knowledge of the current irradiance which can now be provided directly from the sky images. Irradiance measurements are accurate to within about 10%. Second, we demonstrate a virtual sky imager testbed that can be used for validating and enhancing the forecast algorithm. The testbed uses high-quality (but slow) simulations to produce virtual clouds and sky images. Because virtual cloud locations are known, much more advanced validation procedures are possible with the virtual testbed than with measured data. In this way, we are able to determine that camera geometry and non-uniform evolution of the cloud field are the two largest sources of forecast error. Finally, with the assistance of the virtual sky imager testbed, we develop improvements to the cloud advection model used for forecasting. The new advection schemes are 10-20% better at short time horizons.

Secondary wavelength stabilization of unbalanced Michelson interferometers for the generation of low-jitter pulse trains.

Science.gov (United States)

Shalloo, R J; Corner, L

2016-09-01

We present a double unbalanced Michelson interferometer producing up to four output pulses from a single input pulse. The interferometer is stabilized with the Hänsch-Couillaud method using an auxiliary low power continuous wave laser injected into the interferometer, allowing the stabilization of the temporal jitter of the output pulses to 0.02 fs. Such stabilized pulse trains would be suitable for driving multi-pulse laser wakefield accelerators, and the technique could be extended to include amplification in the arms of the interferometer.

Femto-second synchronisation with a waveguide interferometer

Science.gov (United States)

Dexter, A. C.; Smith, S. J.; Woolley, B. J.; Grudiev, A.

2018-03-01

CERN's compact linear collider CLIC requires crab cavities on opposing linacs to rotate bunches of particles into alignment at the interaction point (IP). These cavities are located approximately 25 metres either side of the IP. The luminosity target requires synchronisation of their RF phases to better than 5 fs r.m.s. This is to be achieved by powering both cavities from one high power RF source, splitting the power and delivering it along two waveguide paths that are controlled to be identical in length to within a micrometre. The waveguide will be operated as an interferometer. A high power phase shifter for adjusting path lengths has been successfully developed and operated in an interferometer. The synchronisation target has been achieved in a low power prototype system.

Teologia ekonomiczna, rządzenie i neoliberalizm. Lekcje z "Królestwa i Chwały"

Directory of Open Access Journals (Sweden)

German Eduardo Primera

2015-04-01

Full Text Available Celem artykułu jest sprawdzenie Agambenowskich badań w obszarze teologii ekonomicznej w celu podkreślenia ich znaczenia dla krytyki współczesnej polityki neoliberalnej. W pierwszej części autor przedstawia podsumowanie głównych tez zawartych w książce Królestwo i chwała. W szczególności skupia się zarówno na ujęciu oikonomii we wczesnochrześcijańskich debatach na boską trójcą, jak i jej związku z prowidencjalnym paradygmatem rządzenia. Następnie pokazuje, jak ta genealogia oikonomii może być przydatna dla politycznej analizy teraźniejszości. Stanowi to jednocześnie odpowiedź na niektóre z zarzutów postawionych Królestwu i chwale przez Alberta Toscano. W końcowej części autor podsumowuje swoje rozważania, pokazując szczególne znaczenie prac Agambena dla badań nad polityczną racjonalnością neoliberalizmu.

Social media analytics and research testbed (SMART: Exploring spatiotemporal patterns of human dynamics with geo-targeted social media messages

Directory of Open Access Journals (Sweden)

Jiue-An Yang

2016-06-01

Full Text Available The multilevel model of meme diffusion conceptualizes how mediated messages diffuse over time and space. As a pilot application of implementing the meme diffusion, we developed the social media analytics and research testbed to monitor Twitter messages and track the diffusion of information in and across different cities and geographic regions. Social media analytics and research testbed is an online geo-targeted search and analytics tool, including an automatic data processing procedure at the backend and an interactive frontend user interface. Social media analytics and research testbed is initially designed to facilitate (1 searching and geo-locating tweet topics and terms in different cities and geographic regions; (2 filtering noise from raw data (such as removing redundant retweets and using machine learning methods to improve precision; (3 analyzing social media data from a spatiotemporal perspective; and (4 visualizing social media data in diagnostic ways (such as weekly and monthly trends, trend maps, top media, top retweets, top mentions, or top hashtags. Social media analytics and research testbed provides researchers and domain experts with a tool that can efficiently facilitate the refinement, formalization, and testing of research hypotheses or questions. Three case studies (flu outbreaks, Ebola epidemic, and marijuana legalization are introduced to illustrate how the predictions of meme diffusion can be examined and to demonstrate the potentials and key functions of social media analytics and research testbed.

Two-photon interference of polarization-entangled photons in a Franson interferometer.

Science.gov (United States)

Kim, Heonoh; Lee, Sang Min; Kwon, Osung; Moon, Han Seb

2017-07-18

We present two-photon interference experiments with polarization-entangled photon pairs in a polarization-based Franson-type interferometer. Although the two photons do not meet at a common beamsplitter, a phase-insensitive Hong-Ou-Mandel type two-photon interference peak and dip fringes are observed, resulting from the two-photon interference effect between two indistinguishable two-photon probability amplitudes leading to a coincidence detection. A spatial quantum beating fringe is also measured for nondegenerate photon pairs in the same interferometer, although the two-photon states have no frequency entanglement. When unentangled polarization-correlated photons are used as an input state, the polarization entanglement is successfully recovered through the interferometer via delayed compensation.

Measurements of Interferometer Parameters at Reception of GLONASS and GPS Signals

Directory of Open Access Journals (Sweden)

Nechaeva M.

2016-10-01

Full Text Available The present paper deals with the calibration method of interferometers with antennas having a small effective area, on the quasinoise signals of GLONASS and GPS navigation satellites. Algorithms for calculation of antenna coordinates and instrumental delay from the analysis of correlation interferometer response to signals of satellites in the near field of the instrument were reviewed. The method was tested in VLBI experiments on interferometers with medium and large baselines that included radio telescopes of NIRFI and VIRAC. The values of the antenna coordinates and instrumental delay with an error within the limits of one discrete were obtained. The sources of measurement errors and ways to improve the accuracy of results were analysed.

Optical refractometer based on an asymmetrical twin-core fiber Michelson interferometer.

Science.gov (United States)

Zhou, Ai; Zhang, Yanhui; Li, Guangping; Yang, Jun; Wang, Yuzhuo; Tian, Fengjun; Yuan, Libo

2011-08-15

We report and demonstrate an optical refractometer based on a compact fiber Michelson interferometer. The Michelson interferometer is composed of an asymmetrical twin-core fiber containing a central core and a side core. By chemically etching a segment of the twin-core fiber until the side core is exposed, the effective index of the side core in the etched region is sensitive to the environmental refractive index, which leads to a shift of the transmission spectrum of the Michelson interferometer. The experimental results show that such a device has a refractive index resolution of more than 800 nm/refractive index unit in the range of 1.34-1.37. © 2011 Optical Society of America

A wide-band laser interferometer for the detection of gravitational radiation

International Nuclear Information System (INIS)

Billing, H.; Maischberger, K.; Ruediger, A.; Schilling, R.; Schnupp, L.; Winkler, W.

1979-02-01

The aim of the current investigations of the model interferometer is to gather quantitative data on different noise effects (some of which were rather unexpected), and to develop methods to cope with them. This knowledge will be the basis for a better design of an interferometer of increased path length. The interferometer, in its present form, is not meant for detecting gravitational waves, and the sensitivity currently obtained does not reach that of resonant bars. If the 1-Watt shot-noise limit could be reached, with 300 reflections in the delay line, this model could, however, be an order of magnitude more sensitive than room-temperature resonant bars. (orig.) 891 WB/orig. 892 MAB

Near-infrared spectral imaging Michelson interferometer for astronomical applications

Science.gov (United States)

Wells, C. W.; Potter, A. E.; Morgan, T. H.

1980-01-01

The design and operation of an imaging Michelson interferometer-spectrometer used for near-infrared (0.8 micron to 2.5 microns) spectral imaging are reported. The system employs a rapid scan interferometer modified for stable low resolution (250/cm) performance and a 42 element PbS linear detector array. A microcomputer system is described which provides data acquisition, coadding, and Fourier transformation for near real-time presentation of the spectra of all 42 scene elements. The electronic and mechanical designs are discussed and telescope performance data presented.

An active interferometer-stabilization scheme with linear phase control

DEFF Research Database (Denmark)

Andresen, Esben Ravn; Krishnamachari, v v; Potma, E O

2006-01-01

We report a simple and robust computer-based active interferometer stabilization scheme which does not require modulation of the interfering beams and relies on an error signal which is linearly related to the optical path difference. In this setup, a non-collinearly propagating reference laser...... beam stabilizes the interference output of the laser light propagating collinearly through the interferometer. This stabilization scheme enables adjustable phase control with 20 ms switching times in the range from 0.02π radians to 6π radians at 632.8 nm....

Stan wojenny w syntezach dziejów PRL. Próba analizy historiograficznej

OpenAIRE

Brzechczyn, Krzysztof

2008-01-01

Celem artykułu jest rekonstrukcja obrazu stanu wojennego występującego w następujących syntezach dziejów PRL: A. Czubiński, "Najnowsze dzieje Polski 1944-1983" i "Polska i Polacy po II wojnie światowej", A. Friszke, "Polska. Losy państwa i narodu", A. Paczkowski, "Pół wieku dziejów Polski, 1939-1989", W. Roszkowski, "Najnowsza historia Polski, 1945-2002",t. II-III, A.L. Sowa, "Od Drugiej do Trzeciej Rzeczypospolitej (1945-2001)". Wymienione dzieła analizowane są według następujących kryteri...

RSS SSM/I OCEAN PRODUCT GRIDS DAILY FROM DMSP F11 NETCDF V7

Data.gov (United States)

National Aeronautics and Space Administration — This dataset is part of the collection of Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Sounder (SSMIS) data products produced as part...

Benchmarking Diagnostic Algorithms on an Electrical Power System Testbed

Science.gov (United States)

Kurtoglu, Tolga; Narasimhan, Sriram; Poll, Scott; Garcia, David; Wright, Stephanie

2009-01-01

Diagnostic algorithms (DAs) are key to enabling automated health management. These algorithms are designed to detect and isolate anomalies of either a component or the whole system based on observations received from sensors. In recent years a wide range of algorithms, both model-based and data-driven, have been developed to increase autonomy and improve system reliability and affordability. However, the lack of support to perform systematic benchmarking of these algorithms continues to create barriers for effective development and deployment of diagnostic technologies. In this paper, we present our efforts to benchmark a set of DAs on a common platform using a framework that was developed to evaluate and compare various performance metrics for diagnostic technologies. The diagnosed system is an electrical power system, namely the Advanced Diagnostics and Prognostics Testbed (ADAPT) developed and located at the NASA Ames Research Center. The paper presents the fundamentals of the benchmarking framework, the ADAPT system, description of faults and data sets, the metrics used for evaluation, and an in-depth analysis of benchmarking results obtained from testing ten diagnostic algorithms on the ADAPT electrical power system testbed.

Semi-classical description of matter wave interferometers and hybrid quantum systems

Energy Technology Data Exchange (ETDEWEB)

Schneider, Mathias

2015-02-16

This work considers the semi-classical description of two applications involving cold atoms. This is, on one hand, the behavior of a BOSE-EINSTEIN condensate in hybrid systems, i.e. in contact with a microscopic object (carbon nanotubes, fullerenes, etc.). On the other, the evolution of phase space distributions in matter wave interferometers utilizing ray tracing methods was discussed. For describing condensates in hybrid systems, one can map the GROSS-PITAEVSKII equation, a differential equation in the complex-valued macroscopic wave function, onto a system of two differential equations in density and phase. Neglecting quantum dispersion, one obtains a semiclassical description which is easily modified to incorporate interactions between condensate and microscopical object. In our model, these interactions comprise attractive forces (CASIMIR-POLDER forces) and loss of condensed atoms due to inelastic collisions at the surface of the object. Our model exhibited the excitation of sound waves that are triggered by the object's rapid immersion, and spread across the condensate thereafter. Moreover, local particle loss leads to a shrinking of the bulk condensate. We showed that the total number of condensed particles is decreasing potentially in the beginning (large condensate, strong mean field interaction), while it decays exponentially in the long-time limit (small condensate, mean field inetraction negligible). For representing the physics of matter wave interferometers in phase space, we utilized the WIGNER function. In semi-classical approximation, which again consists in ignoring the quantum dispersion, this representation is subject to the same equation of motion as classical phase space distributions, i.e. the LIOUVILLE equation. This implies that time evolution of theWIGNER function follows a phase space flow that consists of classical trajectories (classical transport). This means, for calculating a time-evolved distribution, one has know the initial

Naked eye picometer resolution in a Michelson interferometer using conjugated twisted beams.

Science.gov (United States)

Emile, Olivier; Emile, Janine

2017-01-15

Michelson interferometry is one of the most widely used techniques for accuracy measurements. Its main characteristic feature is to infer a displacement in one of the arms of the interferometer from a phase measurement. Two different twisted beams, also called vortex beams, with opposite twisted rotations in each arm of the interferometer interfere in a daisy flower-like pattern. The number of petals is twice the topological charge. Their position depends on the relative phase of the beams. Naked eye detection of 44 pm displacements is achieved. The sensitivity of such an interferometer together with possible further improvements, and applications are then discussed.

Intensity profiles behind a five-stage neutron interferometer

International Nuclear Information System (INIS)

Kischko, U.

1983-01-01

By means of the quantitative photography intensity profiles behind a five-stage ideal-crystal neutron interferometer at the thermal channel H25 of the high-flux reactor at the institute Laue-Langevin in Grenoble/France were dermined and compared with theoretical profiles. Contravily to X-rays by neutrons the hole Borrmann range is excited. This leads in the interference picture to superposition of several wave field components. It was shown that the spherical wave theory, as it was developed by W. Bauspiess, U. Bonse, and W. Graeff for the absorption-free neutron interferometer, describes well quantitatively the experimental intensity profiles. Expecially for the t-2t-t geometry the theoretically predicted focusing was confirmed. For the H-beam the intensity profile is symmetric and spatially limited; the O-beam is asymetric with intensities decreasing slowly up to the boundary. Geometrical differences within single stages lead to unique changes in the intensity profile. The pigtail pattern leading in the past to some puzzle guessing could be explained by the influence of geometrical defocusings on the phase shift. Important conclusions for the geometrical tolerances, which have to be regarded in the construction of neutron interferometers, could be obtained. (orig.) [de

Silicon Integrated Dual-Mode Interferometer with Differential Outputs

Directory of Open Access Journals (Sweden)

Niklas Hoppe

2017-09-01

Full Text Available The dual-mode interferometer (DMI is an attractive alternative to Mach-Zehnder interferometers for sensor purposes, achieving sensitivities to refractive index changes close to state-of-the-art. Modern designs on silicon-on-insulator (SOI platforms offer thermally stable and compact devices with insertion losses of less than 1 dB and high extinction ratios. Compact arrays of multiple DMIs in parallel are easy to fabricate due to the simple structure of the DMI. In this work, the principle of operation of an integrated DMI with differential outputs is presented which allows the unambiguous phase shift detection with a single wavelength measurement, rather than using a wavelength sweep and evaluating the optical output power spectrum. Fluctuating optical input power or varying attenuation due to different analyte concentrations can be compensated by observing the sum of the optical powers at the differential outputs. DMIs with two differential single-mode outputs are fabricated in a 250 nm SOI platform, and corresponding measurements are shown to explain the principle of operation in detail. A comparison of DMIs with the conventional Mach-Zehnder interferometer using the same technology concludes this work.

Interferometer for measuring the dynamic surface topography of a human tear film

Science.gov (United States)

Primeau, Brian C.; Greivenkamp, John E.

2012-03-01

The anterior refracting surface of the eye is the thin tear film that forms on the surface of the cornea. Following a blink, the tear film quickly smoothes and starts to become irregular after 10 seconds. This irregularity can affect comfort and vision quality. An in vivo method of characterizing dynamic tear films has been designed based upon a near-infrared phase-shifting interferometer. This interferometer continuously measures light reflected from the tear film, allowing sub-micron analysis of the dynamic surface topography. Movies showing the tear film behavior can be generated along with quantitative metrics describing changes in the tear film surface. This tear film measurement allows analysis beyond capabilities of typical fluorescein visual inspection or corneal topography and provides better sensitivity and resolution than shearing interferometry methods. The interferometer design is capable of identifying features in the tear film much less than a micron in height with a spatial resolution of about ten microns over a 6 mm diameter. This paper presents the design of the tear film interferometer along with the considerations that must be taken when designing an interferometer for on-eye diagnostics. Discussions include eye movement, design of null optics for a range of ocular geometries, and laser emission limits for on-eye interferometry.

Space Station technology testbed: 2010 deep space transport

Science.gov (United States)

Holt, Alan C.

1993-01-01

A space station in a crew-tended or permanently crewed configuration will provide major R&D opportunities for innovative, technology and materials development and advanced space systems testing. A space station should be designed with the basic infrastructure elements required to grow into a major systems technology testbed. This space-based technology testbed can and should be used to support the development of technologies required to expand our utilization of near-Earth space, the Moon and the Earth-to-Jupiter region of the Solar System. Space station support of advanced technology and materials development will result in new techniques for high priority scientific research and the knowledge and R&D base needed for the development of major, new commercial product thrusts. To illustrate the technology testbed potential of a space station and to point the way to a bold, innovative approach to advanced space systems' development, a hypothetical deep space transport development and test plan is described. Key deep space transport R&D activities are described would lead to the readiness certification of an advanced, reusable interplanetary transport capable of supporting eight crewmembers or more. With the support of a focused and highly motivated, multi-agency ground R&D program, a deep space transport of this type could be assembled and tested by 2010. Key R&D activities on a space station would include: (1) experimental research investigating the microgravity assisted, restructuring of micro-engineered, materials (to develop and verify the in-space and in-situ 'tuning' of materials for use in debris and radiation shielding and other protective systems), (2) exposure of microengineered materials to the space environment for passive and operational performance tests (to develop in-situ maintenance and repair techniques and to support the development, enhancement, and implementation of protective systems, data and bio-processing systems, and virtual reality and

Increased interference fringe visibility from the post-fabrication heat treatment of a perfect crystal silicon neutron interferometer

Science.gov (United States)

Heacock, B.; Arif, M.; Cory, D. G.; Gnaeupel-Herold, T.; Haun, R.; Huber, M. G.; Jamer, M. E.; Nsofini, J.; Pushin, D. A.; Sarenac, D.; Taminiau, I.; Young, A. R.

2018-02-01

We find that annealing a previously chemically etched interferometer at 800 °C dramatically increased the interference fringe visibility from 23% to 90%. The Bragg plane misalignments were also measured before and after annealing using neutron rocking curves, showing that Bragg plane alignment was improved across the interferometer after annealing. This suggests that current interferometers with low fringe visibility may be salvageable and that annealing may become an important step in the fabrication process of future neutron interferometers, leading to less need for chemical etching and larger more exotic neutron interferometers.

Counter electrojet features in the Brazilian sector: simultaneous observation by radar, digital sounder and magnetometers

Directory of Open Access Journals (Sweden)

C. M. Denardini

2009-04-01

Full Text Available In the present work we show new results regarding equatorial counter electrojet (CEJ events in the Brazilian sector, based on the RESCO radar, two set of fluxgate magnetometer systems and a digital sounder. RESCO radar is a 50 MHz backscatter coherent radar installed in 1998 at São Luís (SLZ, 2.33° S, 44.60° W, an equatorial site. The Digital sounder routinely monitors the electron density profile at the radar site. The magnetometer systems are fluxgate-type installed at SLZ and Eusébio (EUS, 03.89° S, 38.44° W. From the difference between the horizontal component of magnetic field at SLZ station and the same component at EUS (EEJ ground strength several cases of westward morning electrojet and its normal inversion to the eastward equatorial electrojet (EEJ have been observed. Also, the EEJ ground strength has shown some cases of CEJ events, which been detected with the RESCO radar too. Detection of these events were investigated with respect to their time and height of occurrence, correlation with sporadic E (Es layers at the same time, and their spectral characteristics as well as the radar echo power intensity.

Design and construction of a 76m long-travel laser enclosure for a space occulter testbed

Science.gov (United States)

Galvin, Michael; Kim, Yunjong; Kasdin, N. Jeremy; Sirbu, Dan; Vanderbei, Robert; Echeverri, Dan; Sagolla, Giuseppe; Rousing, Andreas; Balasubramanian, Kunjithapatham; Ryan, Daniel; Shaklan, Stuart; Lisman, Doug

2016-07-01

Princeton University is upgrading our space occulter testbed. In particular, we are lengthening it to 76m to achieve flightlike Fresnel numbers. This much longer testbed required an all-new enclosure design. In this design, we prioritized modularity and the use of commercial off-the-shelf (COTS) and semi-COTS components. Several of the technical challenges encountered included an unexpected slow beam drift and black paint selection. Herein we describe the design and construction of this long-travel laser enclosure.

Analytic models of spectral responses of fiber-grating-based interferometers on FMC theory.

Science.gov (United States)

Zeng, Xiangkai; Wei, Lai; Pan, Yingjun; Liu, Shengping; Shi, Xiaohui

2012-02-13

In this paper the analytic models (AMs) of the spectral responses of fiber-grating-based interferometers are derived from the Fourier mode coupling (FMC) theory proposed recently. The interferometers include Fabry-Perot cavity, Mach-Zehnder and Michelson interferometers, which are constructed by uniform fiber Bragg gratings and long-period fiber gratings, and also by Gaussian-apodized ones. The calculated spectra based on the analytic models are achieved, and compared with the measured cases and those on the transfer matrix (TM) method. The calculations and comparisons have confirmed that the AM-based spectrum is in excellent agreement with the TM-based one and the measured case, of which the efficiency is improved up to ~2990 times that of the TM method for non-uniform-grating-based in-fiber interferometers.

The three-grating Mach-Zehnder optical interferometer: a tutorial approach using particle optics

International Nuclear Information System (INIS)

Miffre, A; Delhuille, R; Viaris Lesegno, B de; Buechner, M; Rizzo, C; Vigue, J

2002-01-01

In this paper, we present a tutorial set-up based on an optical three-grating Mach-Zehnder interferometer. As this apparatus is very similar in its principle to the Mach-Zehnder interferometers used with matter waves (neutrons, atoms and molecules), it can be used to familiarize students with particle optics, and in our explanations, we use the complementary points of view of wave optics and particle optics. Finally, we have used this interferometer to measure the index of refraction of BK7 glass for red light at 633 nm, with a technique equivalent to the one used to measure the index of refraction of solid matter for thermal neutrons. The dimensions of this interferometer and its cost make it very interesting for laboratory courses and the experiment described here can be reproduced by students

Characterisation of a resolution enhancing image inversion interferometer.

Science.gov (United States)

Wicker, Kai; Sindbert, Simon; Heintzmann, Rainer

2009-08-31

Image inversion interferometers have the potential to significantly enhance the lateral resolution and light efficiency of scanning fluorescence microscopes. Self-interference of a point source's coherent point spread function with its inverted copy leads to a reduction in the integrated signal for off-axis sources compared to sources on the inversion axis. This can be used to enhance the resolution in a confocal laser scanning microscope. We present a simple image inversion interferometer relying solely on reflections off planar surfaces. Measurements of the detection point spread function for several types of light sources confirm the predicted performance and suggest its usability for scanning confocal fluorescence microscopy.

Autonomous power expert fault diagnostic system for Space Station Freedom electrical power system testbed

Science.gov (United States)

Truong, Long V.; Walters, Jerry L.; Roth, Mary Ellen; Quinn, Todd M.; Krawczonek, Walter M.

1990-01-01

The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control to the Space Station Freedom Electrical Power System (SSF/EPS) testbed being developed and demonstrated at NASA Lewis Research Center. The objectives of the program are to establish artificial intelligence technology paths, to craft knowledge-based tools with advanced human-operator interfaces for power systems, and to interface and integrate knowledge-based systems with conventional controllers. The Autonomous Power EXpert (APEX) portion of the APS program will integrate a knowledge-based fault diagnostic system and a power resource planner-scheduler. Then APEX will interface on-line with the SSF/EPS testbed and its Power Management Controller (PMC). The key tasks include establishing knowledge bases for system diagnostics, fault detection and isolation analysis, on-line information accessing through PMC, enhanced data management, and multiple-level, object-oriented operator displays. The first prototype of the diagnostic expert system for fault detection and isolation has been developed. The knowledge bases and the rule-based model that were developed for the Power Distribution Control Unit subsystem of the SSF/EPS testbed are described. A corresponding troubleshooting technique is also described.

Applications of the lateral shearing interferometer in measurement of synchrotron radiation optical elements

International Nuclear Information System (INIS)

Liu, Wu-ming; Takacs, P.Z.; Siddons, D.P.

1987-11-01

The use of a single plate shearing, or Murty, interferometer for measuring the surface quality of several optical elements is reviewed and several results are given. The principle of the Murty interferometer is also explained

Validation of separated source frequency delivery for a fiber-coupled heterodyne displacement interferometer

NARCIS (Netherlands)

Meskers, A.J.H.; Spronck, J.W.; Munnig Schmidt, R.H.

2014-01-01

The use of optical fibers presents several advantages with respect to free-space optical transport regarding sourcefrequency delivery to individual heterodyne interferometers. Unfortunately, fiber delivery to individual coaxial heterodyne interferometers leads to an increase of (periodic)

Sub-shot-noise phase sensitivity with a Bose-Einstein condensate Mach-Zehnder interferometer

International Nuclear Information System (INIS)

Pezze, L.; Smerzi, A.; Collins, L.A.; Berman, G.P.; Bishop, A.R.

2005-01-01

Bose-Einstein condensates (BEC), with their coherence properties, have attracted wide interest for their possible application to ultraprecise interferometry and ultraweak force sensors. Since condensates, unlike photons, are interacting, they may permit the realization of specific quantum states needed as input of an interferometer to approach the Heisenberg limit, the supposed lower bound to precision phase measurements. To this end, we study the sensitivity to external weak perturbations of a representative matter-wave Mach-Zehnder interferometer whose input are two Bose-Einstein condensates created by splitting a single condensate in two parts. The interferometric phase sensitivity depends on the specific quantum state created with the two condensates, and, therefore, on the time scale of the splitting process. We identify three different regimes, characterized by a phase sensitivity Δθ scaling with the total number of condensate particles N as (i) the standard quantum limit Δθ∼1/N 1/2 (ii) the sub shot-noise Δθ∼1/N 3/4 , and the (iii) the Heisenberg limit Δθ∼1/N. However, in a realistic dynamical BEC splitting, the 1/N limit requires a long adiabaticity time scale, which is hardly reachable experimentally. On the other hand, the sub-shot-noise sensitivity Δθ∼1/N 3/4 can be reached in a realistic experimental setting. We also show that the 1/N 3/4 scaling is a rigorous upper bound in the limit N→∞, while keeping constant all different parameters of the bosonic Mach-Zehnder interferometer

Development of optical packet and circuit integrated ring network testbed.

Science.gov (United States)

Furukawa, Hideaki; Harai, Hiroaki; Miyazawa, Takaya; Shinada, Satoshi; Kawasaki, Wataru; Wada, Naoya

2011-12-12

We developed novel integrated optical packet and circuit switch-node equipment. Compared with our previous equipment, a polarization-independent 4 × 4 semiconductor optical amplifier switch subsystem, gain-controlled optical amplifiers, and one 100 Gbps optical packet transponder and seven 10 Gbps optical path transponders with 10 Gigabit Ethernet (10GbE) client-interfaces were newly installed in the present system. The switch and amplifiers can provide more stable operation without equipment adjustments for the frequent polarization-rotations and dynamic packet-rate changes of optical packets. We constructed an optical packet and circuit integrated ring network testbed consisting of two switch nodes for accelerating network development, and we demonstrated 66 km fiber transmission and switching operation of multiplexed 14-wavelength 10 Gbps optical paths and 100 Gbps optical packets encapsulating 10GbE frames. Error-free (frame error rate optical packets of various packet lengths and packet rates, and stable operation of the network testbed was confirmed. In addition, 4K uncompressed video streaming over OPS links was successfully demonstrated. © 2011 Optical Society of America

Analysis of the localization of Michelson interferometer fringes using Fourier optics and temporal coherence

International Nuclear Information System (INIS)

Narayanamurthy, C S

2009-01-01

Fringes formed in a Michelson interferometer never localize in any plane, in the detector plane and in the localization plane. Instead, the fringes are assumed to localize at infinity. Except for some explanation in Principles of Optics by Born and Wolf (1964 (New York: Macmillan)), the fringe localization phenomena of Michelson's interferometer have never been analysed seriously in any book. Because Michelson's interferometer is one of the important and fundamental optical experiments taught at both undergraduate and graduate levels, it would be appropriate to explain the localization of these fringes. In this paper, we analyse the localization of Michelson interferometer fringes using Fourier optics and temporal coherence, and show that they never localize at any plane even at infinity

Mechanical Description of the Mars Climate Sounder Instrument

Science.gov (United States)

Jau, Bruno M.

2008-01-01

This paper introduces the Mars Climate Sounder (MCS) Instrument of the Mars Reconnaissance Orbiter (MRO) spacecraft. The instrument scans the Martian atmosphere almost continuously to systematically acquire weather and climate observations over time. Its primary components are an optical bench that houses dual telescopes with a total of nine channels for visible and infrared sensing, and a two axis gimbal that provides pointing capabilities. Both rotating joints consist of an integrated actuator with a hybrid planetary/harmonic transmission and a twist cap section that enables the electrical wiring to pass through the rotating joint. Micro stepping is used to reduce spacecraft disturbance torques to acceptable levels while driving the stepper motors. To ensure survivability over its four year life span, suitable mechanical components, lubrication, and an active temperature control system were incorporated. Some life test results and lessons learned are provided to serve as design guidelines for actuator parts and flex cables.

Passive Thermal Design Approach for the Space Communications and Navigation (SCaN) Testbed Experiment on the International Space Station (ISS)

Science.gov (United States)

Siamidis, John; Yuko, Jim

2014-01-01

The Space Communications and Navigation (SCaN) Program Office at NASA Headquarters oversees all of NASAs space communications activities. SCaN manages and directs the ground-based facilities and services provided by the Deep Space Network (DSN), Near Earth Network (NEN), and the Space Network (SN). Through the SCaN Program Office, NASA GRC developed a Software Defined Radio (SDR) testbed experiment (SCaN testbed experiment) for use on the International Space Station (ISS). It is comprised of three different SDR radios, the Jet Propulsion Laboratory (JPL) radio, Harris Corporation radio, and the General Dynamics Corporation radio. The SCaN testbed experiment provides an on-orbit, adaptable, SDR Space Telecommunications Radio System (STRS) - based facility to conduct a suite of experiments to advance the Software Defined Radio, Space Telecommunications Radio Systems (STRS) standards, reduce risk (Technology Readiness Level (TRL) advancement) for candidate Constellation future space flight hardware software, and demonstrate space communication links critical to future NASA exploration missions. The SCaN testbed project provides NASA, industry, other Government agencies, and academic partners the opportunity to develop and field communications, navigation, and networking technologies in the laboratory and space environment based on reconfigurable, software defined radio platforms and the STRS Architecture.The SCaN testbed is resident on the P3 Express Logistics Carrier (ELC) on the exterior truss of the International Space Station (ISS). The SCaN testbed payload launched on the Japanese Aerospace Exploration Agency (JAXA) H-II Transfer Vehicle (HTV) and was installed on the ISS P3 ELC located on the inboard RAM P3 site. The daily operations and testing are managed out of NASA GRC in the Telescience Support Center (TSC).

Modeling of Performance And Safety of a Multi-Task Unmanned Autonomous Maritime Vehicle / Modelowanie Ruchu i Bezpieczeństwa Wielozadaniowego Bezzałogowego Autonomicznego Pojazdu Wodnego

Directory of Open Access Journals (Sweden)

Gerigk Mirosław K.

2015-09-01

Full Text Available W początkowej części artykułu przedstawiono cel badań. Następnie, opisano metodę badań. Potem, zaprezentowano przedmiot badań: bezzałogowy autonomiczny pojazd wodny. Z kolei, przedstawiono model zachowania się pojazdu, w tym jego balastowania i ruchu. W artykule przedstawiono wybrane informacje na temat zintegrowanego systemu sterowania, pozycjonowania i stabilizacji pojazdu. Taki system umożliwia otrzymanie w pełni autonomicznego pojazdu. W końcowej części pracy przedstawiono wybrane problemy związane z oceną ryzyka i bezpieczeństwa pojazdu.

Novel birefringence interrogation for Sagnac loop interferometer sensor with unlimited linear measurement range.

Science.gov (United States)

He, Haijun; Shao, Liyang; Qian, Heng; Zhang, Xinpu; Liang, Jiawei; Luo, Bin; Pan, Wei; Yan, Lianshan

2017-03-20

A novel demodulation method for Sagnac loop interferometer based sensor has been proposed and demonstrated, by unwrapping the phase changes with birefringence interrogation. A temperature sensor based on Sagnac loop interferometer has been used to verify the feasibility of the proposed method. Several tests with 40 °C temperature range have been accomplished with a great linearity of 0.9996 in full range. The proposed scheme is universal for all Sagnac loop interferometer based sensors and it has unlimited linear measurable range which overwhelming the conventional demodulation method with peak/dip tracing. Furthermore, the influence of the wavelength sampling interval and wavelength span on the demodulation error has been discussed in this work. The proposed interrogation method has a great significance for Sagnac loop interferometer sensor and it might greatly enhance the availability of this type of sensors in practical application.

Mirrors used in the LIGO interferometers for first detection of gravitational waves.

Science.gov (United States)

Pinard, L; Michel, C; Sassolas, B; Balzarini, L; Degallaix, J; Dolique, V; Flaminio, R; Forest, D; Granata, M; Lagrange, B; Straniero, N; Teillon, J; Cagnoli, G

2017-02-01

For the first time, direct detection of gravitational waves occurred in the Laser Interferometer Gravitational-wave Observatory (LIGO) interferometers. These advanced detectors require large fused silica mirrors with optical and mechanical properties and have never been reached until now. This paper details the main achievements of these ion beam sputtering coatings.

Frequency-tuned microwave photon counter based on a superconductive quantum interferometer

Science.gov (United States)

Shnyrkov, V. I.; Yangcao, Wu; Soroka, A. A.; Turutanov, O. G.; Lyakhno, V. Yu.

2018-03-01

Various types of single-photon counters operating in infrared, ultraviolet, and optical wavelength ranges are successfully used to study electromagnetic fields, analyze radiation sources, and solve problems in quantum informatics. However, their operating principles become ineffective at millimeter band, S-band, and ultra-high frequency bands of wavelengths due to the decrease in quantum energy by 4-5 orders of magnitude. Josephson circuits with discrete Hamiltonians and qubits are a good foundation for the construction of single-photon counters at these frequencies. This paper presents a frequency-tuned microwave photon counter based on a single-junction superconducting quantum interferometer and flux qutrit. The control pulse converts the interferometer into a two-level system for resonance absorption of photons. Decay of the photon-induced excited state changes the magnetic flux in the interferometer, which is measured by a SQUID magnetometer. Schemes for recording the magnetic flux using a DC SQUID or ideal parametric detector, based on a qutrit with high-frequency excitation, are discussed. It is shown that the counter consisting of an interferometer with a Josephson junction and a parametric detector demonstrates high performance and is capable of detecting single photons in a microwave band.

Plasma density measurements from the GEOS-1 relaxation sounder

International Nuclear Information System (INIS)

Etcheto, J.; Bloch, J.J.

1978-01-01

The relaxation sounder uses the characteristics of the propagation of radiowaves to sound the plasma surrounding the spacecraft. It determines, in particular, the plasma frequency, which gives the electron density. Measurements over the whole dayside of the magnetosphere, from the evening to the night sectors, are now available. The behaviour of the plasma resonance depends on local time, the nighttime echoes being generally weaker. Density measurements thus obtained are shown and discussed in the context of what is presently known about the plasma distribution in the magnetosphere. In particular, the density around apogee is studied as a function of magnetic activity. On the dayside, it appears to vary between a few and a few tens of electrons per cubic centimeter. The evolution of the density profile for several consecutive days is studied and interpreted tracing back the drift of the particles. (Auth.)

Automatic detection of subglacial lakes in radar sounder data acquired in Antarctica

Science.gov (United States)

Ilisei, Ana-Maria; Khodadadzadeh, Mahdi; Dalsasso, Emanuele; Bruzzone, Lorenzo

2017-10-01

Subglacial lakes decouple the ice sheet from the underlying bedrock, thus facilitating the sliding of the ice masses towards the borders of the continents, consequently raising the sea level. This motivated increasing attention in the detection of subglacial lakes. So far, about 70% of the total number of subglacial lakes in Antarctica have been detected by analysing radargrams acquired by radar sounder (RS) instruments. Although the amount of radargrams is expected to drastically increase, from both airborne and possible future Earth observation RS missions, currently the main approach to the detection of subglacial lakes in radargrams is by visual interpretation. This approach is subjective and extremely time consuming, thus difficult to apply to a large amount of radargrams. In order to address the limitations of the visual interpretation and to assist glaciologists in better understanding the relationship between the subglacial environment and the climate system, in this paper, we propose a technique for the automatic detection of subglacial lakes. The main contribution of the proposed technique is the extraction of features for discriminating between lake and non-lake basal interfaces. In particular, we propose the extraction of features that locally capture the topography of the basal interface, the shape and the correlation of the basal waveforms. Then, the extracted features are given as input to a supervised binary classifier based on Support Vector Machine to perform the automatic subglacial lake detection. The effectiveness of the proposed method is proven both quantitatively and qualitatively by applying it to a large dataset acquired in East Antarctica by the MultiChannel Coherent Radar Depth Sounder.

Analysis, modeling, and simulation (AMS) testbed development and evaluation to support dynamic mobility applications (DMA) and active transportation and demand management (ATDM) programs - evaluation summary for the San Diego testbed

Science.gov (United States)

2017-08-01

The primary objective of this project is to develop multiple simulation testbeds and transportation models to evaluate the impacts of Connected Vehicle Dynamic Mobility Applications (DMA) and Active Transportation and Demand Management (ATDM) strateg...

Analysis, Modeling, and Simulation (AMS) Testbed Development and Evaluation to Support Dynamic Mobility Applications (DMA) and Active Transportation and Demand Management (ATDM) Programs - Evaluation Report for the San Diego Testbed

Science.gov (United States)

2017-07-01

The primary objective of this project is to develop multiple simulation testbeds and transportation models to evaluate the impacts of Connected Vehicle Dynamic Mobility Applications (DMA) and Active Transportation and Demand Management (ATDM) strateg...

NEuclid: a long-range tilt-immune homodyne interferometer

Science.gov (United States)

Bradshaw, M. J.; Speake, C. C.

2017-11-01

The new Easy to Use Compact Laser Interferometric Device (nEUCLID) is a polarisation-based homodyne interferometer with substantially unequal arms that is tolerant to target mirror tilt. The design has no active components, uses standard optical components of 25 mm diameter, has a working distance of 706 mm and a reference arm-length of 21 mm. nEUCLID optics have a footprint of 210 x 190 x 180 mm, and has a tolerance to target mirror tilt of +/- 0.5 degrees, made possible by a novel new retro-reflector design [1]. nEUCLID was built to a set of specifications laid down by Airbus Defence and Space, who required a lowmass, low-power device to measure displacement with nanometre accuracy for space applications. At the University of Birmingham we have previously built a smaller, more compact tilt-insensitive homodyne interferometer - the EUCLID [2, 3, 4] - which has a working distance of 6 mm, a working range of +/- 3 mm, and a tilt range of +/- 1° [2]. We created a new optical design to allow a much larger working distance to be achieved (as discussed in Section II) and used this in a new interferometer - the nEUCLID. Section II describes the interferometer in detail; how nEUCLID is tilt insensitive, and the optical configuration. Section III states the design specifications from Airbus Defence and Space and the components used in the final design. The output interference pattern from nEUCLID, and how it has been corrected with a meniscus lens, is also discussed. In Section IV we discuss the results demonstrating the tilt immunity range, and the sensitivity of the device. Section V describes several potential applications of nEUCLID, and Section VI draws together our conclusions.

CanOpen on RASTA: The Integration of the CanOpen IP Core in the Avionics Testbed

Science.gov (United States)

Furano, Gianluca; Guettache, Farid; Magistrati, Giorgio; Tiotto, Gabriele; Ortega, Carlos Urbina; Valverde, Alberto

2013-08-01

This paper presents the work done within the ESA Estec Data Systems Division, targeting the integration of the CanOpen IP Core with the existing Reference Architecture Test-bed for Avionics (RASTA). RASTA is the reference testbed system of the ESA Avionics Lab, designed to integrate the main elements of a typical Data Handling system. It aims at simulating a scenario where a Mission Control Center communicates with on-board computers and systems through a TM/TC link, thus providing the data management through qualified processors and interfaces such as Leon2 core processors, CAN bus controllers, MIL-STD-1553 and SpaceWire. This activity aims at the extension of the RASTA with two boards equipped with HurriCANe controller, acting as CANOpen slaves. CANOpen software modules have been ported on the RASTA system I/O boards equipped with Gaisler GR-CAN controller and acts as master communicating with the CCIPC boards. CanOpen serves as upper application layer for based on CAN defined within the CAN-in-Automation standard and can be regarded as the definitive standard for the implementation of CAN-based systems solutions. The development and integration of CCIPC performed by SITAEL S.p.A., is the first application that aims to bring the CANOpen standard for space applications. The definition of CANOpen within the European Cooperation for Space Standardization (ECSS) is under development.

Direct reading fast microwave interferometer for EBT

International Nuclear Information System (INIS)

Uckan, T.

1984-10-01

A simple and inexpensive 4-mm direct reading fast (rise time approx. 100 μs) microwave interferometer is described. The system is particularly useful for density measurements on the ELMO Bumpy Torus (EBT) during pulsed operation

The use of x-ray interferometry to investigate the linearity of the NPL Differential Plane Mirror Optical Interferometer

Science.gov (United States)

Yacoot, Andrew; Downs, Michael J.

2000-08-01

The x-ray interferometer from the combined optical and x-ray interferometer (COXI) facility at NPL has been used to investigate the performance of the NPL Jamin Differential Plane Mirror Interferometer when it is fitted with stabilized and unstabilized lasers. This Jamin interferometer employs a common path design using a double pass configuration and one fringe is realized by a displacement of 158 nm between its two plane mirror retroreflectors. Displacements over ranges of several optical fringes were measured simultaneously using the COXI x-ray interferometer and the Jamin interferometer and the results were compared. In order to realize the highest measurement accuracy from the Jamin interferometer, the air paths were shielded to prevent effects from air turbulence and electrical signals generated by the photodetectors were analysed and corrected using an optimizing routine in order to subdivide the optical fringes accurately. When an unstabilized laser was used the maximum peak-to-peak difference between the two interferometers was 80 pm, compared with 20 pm when the stabilized laser was used.

Sub-nanometer periodic nonlinearity error in absolute distance interferometers

Science.gov (United States)

Yang, Hongxing; Huang, Kaiqi; Hu, Pengcheng; Zhu, Pengfei; Tan, Jiubin; Fan, Zhigang

2015-05-01

Periodic nonlinearity which can result in error in nanometer scale has become a main problem limiting the absolute distance measurement accuracy. In order to eliminate this error, a new integrated interferometer with non-polarizing beam splitter is developed. This leads to disappearing of the frequency and/or polarization mixing. Furthermore, a strict requirement on the laser source polarization is highly reduced. By combining retro-reflector and angel prism, reference and measuring beams can be spatially separated, and therefore, their optical paths are not overlapped. So, the main cause of the periodic nonlinearity error, i.e., the frequency and/or polarization mixing and leakage of beam, is eliminated. Experimental results indicate that the periodic phase error is kept within 0.0018°.

Impact of local and non-local sources of pollution on background US Ozone: synergy of a low-earth orbiting and geostationary sounder constellation

Science.gov (United States)

Bowman, K. W.; Lee, M.

2015-12-01

Dramatic changes in the global distribution of emissions over the last decade have fundamentally altered source-receptor pollution impacts. A new generation of low-earth orbiting (LEO) sounders complimented by geostationary sounders over North America, Europe, and Asia providing a unique opportunity to quantify the current and future trajectory of emissions and their impact on global pollution. We examine the potential of this constellation of air quality sounders to quantify the role of local and non-local sources of pollution on background ozone in the US. Based upon an adjoint sensitivity method, we quantify the role synoptic scale transport of non-US pollution on US background ozone over months representative of different source-receptor relationships. This analysis allows us distinguish emission trajectories from megacities, e.g. Beijing, or regions, e.g., western China, from natural trends on downwind ozone. We subsequently explore how a combination of LEO and GEO observations could help quantify the balance of local emissions against changes in distant sources . These results show how this unprecedented new international ozone observing system can monitor the changing structure of emissions and their impact on global pollution.

Wide-area phase-contrast X-ray imaging using large X-ray interferometers

Energy Technology Data Exchange (ETDEWEB)

Momose, Atsushi E-mail: momose@exp.t.u-tokyo.ac.jp; Takeda, Tohoru; Yoneyama, Akio; Koyama, Ichiro; Itai, Yuji

2001-07-21

Large X-ray interferometers are developed for phase-contrast X-ray imaging aiming at medical applications. A monolithic X-ray interferometer and a separate one are studied, and currently a 25 mmx20 mm view area can be generated. This paper describes the strategy of our research program and some recent developments.

Wide-area phase-contrast X-ray imaging using large X-ray interferometers

Science.gov (United States)

Momose, Atsushi; Takeda, Tohoru; Yoneyama, Akio; Koyama, Ichiro; Itai, Yuji

2001-07-01

Large X-ray interferometers are developed for phase-contrast X-ray imaging aiming at medical applications. A monolithic X-ray interferometer and a separate one are studied, and currently a 25 mm×20 mm view area can be generated. This paper describes the strategy of our research program and some recent developments.

Handheld ESPI-speckle interferometer

DEFF Research Database (Denmark)

Skov Hansen, René

2003-01-01

. The interferometer presented here is a compact version of the set-up, Which is capable of measuring displacements of small objects, having either a specularly reflecting-or a diffusely scattering surface. The small optical set-up together with the use of the popular USB-communication for acquiring the images...... and controlling the phase of the reference wave constitutes a compact "handheld" instrument and eliminates the need for installing extra hardware, such as frame grabber and Digital to Analog converter, in the host computer....

Experimental investigation of a control scheme for a tuned resonant sideband extraction interferometer for next-generation gravitational-wave detectors

Energy Technology Data Exchange (ETDEWEB)

Kawazoe, F; Sugamoto, A [Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610 (Japan); Sato, S; Leonhardt, V; Yamazaki, T; Fukushima, M; Kawamura, S [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 112-8610 (Japan); Miyakawa, O [California Institute of Technology, Pasadena, CA 91125 (United States); Morioka, T [University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishizawa, A [Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)], E-mail: kawazoe@gravity.mtk.nao.ac.jp

2008-07-15

LCGT plans to use tuned RSE as the optical configuration for its interferometer. A tuned RSE interferometer has five degrees of freedom that need to be controlled in order to operate a gravitational-wave detector, although it is expected to be very challenging because of the complexity of its optical configuration. A new control scheme for a tuned RSE interferometer has been developed and tested with a prototype interferometer to demonstrate successful control of the tuned RSE interferometer. The whole RSE interferometer was successfully locked with the control scheme. Here the control scheme and the current status of the experiment are presented.

Experimental investigation of a control scheme for a tuned resonant sideband extraction interferometer for next-generation gravitational-wave detectors

International Nuclear Information System (INIS)

Kawazoe, F; Sugamoto, A; Sato, S; Leonhardt, V; Yamazaki, T; Fukushima, M; Kawamura, S; Miyakawa, O; Morioka, T; Nishizawa, A

2008-01-01

LCGT plans to use tuned RSE as the optical configuration for its interferometer. A tuned RSE interferometer has five degrees of freedom that need to be controlled in order to operate a gravitational-wave detector, although it is expected to be very challenging because of the complexity of its optical configuration. A new control scheme for a tuned RSE interferometer has been developed and tested with a prototype interferometer to demonstrate successful control of the tuned RSE interferometer. The whole RSE interferometer was successfully locked with the control scheme. Here the control scheme and the current status of the experiment are presented

Laser-based ultrasonics by dual-probe interferometer detection and narrow-band ultrasound generation

Science.gov (United States)

Huang, Jin

1993-01-01

Despite the advantages of laser-based ultrasonic (LBU) systems, the overall sensitivity of LBU systems needs to be improved for practical applications. Progress is reported to achieve better LBU detection accuracy and sensitivity for applications with surface waves and Lamb waves. A novel dual-probe laser interferometer has been developed to measure the same signal at two points. The dual-probe interferometer is a modification of a conventional single-probe interferometer in that the reference beam is guided to a second detecting point on the specimen surface to form a differential measurement mode, which measure the difference of the displacements at the two points. This dual-probe interferometer is particularly useful for accurate measurements of the speed and attenuation of surface waves and Lamb waves. The dual-probe interferometer has been applied to obtain accurate measurements of the surface wave speed and attenuation on surfaces of increasing surface roughness. It has also been demonstrated that with an appropriate signal processing method, namely, the power cepstrum method, the dual-probe interferometer is applicable to measure the local surface wave speed even when the probe separation is so small that the two waveforms in the interferometer output signal overlap in the time domain. Narrow-band signal generation and detection improve the sensitivity of LBU systems. It is proposed to use a diffraction grating to form an array of illuminating strips which form a source of narrowband surface and Lamb waves. The line-array of thermoelastic sources generates narrow-band signals whose frequency and bandwidth can be easily controlled. The optimum line-array parameters, such as width, spacing and the number of lines in the array have been derived theoretically and verified experimentally. Narrow-band signal generation with optimum parameters has been demonstrated. The enhanced LBU system with dual-probe detection and narrowband signal generation has been

Quantum mechanical noise in coherent-state and squeezed-state Michelson interferometers

International Nuclear Information System (INIS)

Assaf, Ohad; Ben-Aryeh, Yacob

2002-01-01

In the present study we extend and generalize previous results for coherent-state and squeezed-state Michelson interferometer quantum mechanical uncertainties (or fluctuations), which are commonly referred to as 'quantum noise'. The calculation of photon counting (PC) fluctuations in the squeezed-state interferometer is extended to fourth-order correlation functions used as the measured signal. We also generalize a 'unified model' for treating both PC and radiation pressure fluctuations in the coherent-state interferometer, by using mathematical methods which apply to Kerr-type interactions. The results are more general than those reported previously in two ways. First, we obtain exact expressions, which lead to previous results under certain approximations. Second, we deal with cases in which the responses of the two mirrors to radiation pressure are not equal

A differential Michelson interferometer with orthogonal single frequency laser for nanometer displacement measurement

International Nuclear Information System (INIS)

Yan, Liping; Chen, Benyong; Wang, Bin

2017-01-01

A novel differential Michelson laser interferometer is proposed to eliminate the influence of environmental fluctuations for nanometer displacement measurement. This differential interferometer consists of two homodyne interferometers in which two orthogonal single frequency beams share common reference arm and partial measurement arm. By modulating the displacement of the common reference arm with a piezoelectric transducer, the common-mode displacement drift resulting from the environmental disturbances can be well suppressed and the measured displacement as differential-mode displacement signal is achieved. In addition, a phase difference compensation method is proposed for accurately determining the phase difference between interference signals by correcting the time interval according to the average speed in one cycle of interference signal. The nanometer displacement measurement experiments were performed to demonstrate the effectiveness and feasibility of the proposed interferometer and show that precision displacement measurement with standard deviation less than 1 nm has been achieved. (paper)

Noise sources in the LTP heterodyne interferometer

International Nuclear Information System (INIS)

Wand, V; Bogenstahl, J; Braxmaier, C; Danzmann, K; GarcIa, A; Guzman, F; Heinzel, G; Hough, J; Jennrich, O; Killow, C; Robertson, D; Sodnik, Z; Steier, F; Ward, H

2006-01-01

The LISA Technology Package uses a heterodyne Mach-Zehnder interferometer to monitor the relative motion of the test masses with picometer accuracy. This paper discusses two classes of noise sources that were identified and investigated during the prototype experiments. Most troublesome are electrically induced sidebands on the light, which give rise to nonlinearities in the interferometer output. Even worse, if the differential pathlength between two optical fibres fluctuates, a noise term of milliradian amplitude appears and completely spoils the performance. We discuss the origin and mitigation of this process. Dissimilar beam shapes of the interfering beams produce another type of noise in conjunction with beam jitter and spatially inhomogeneous photodetectors. To study and minimize this effect, we have built a real-time high-resolution phasefront imaging system that will be used for the production of the flight model

Sun Radio Interferometer Space Experiment (SunRISE)

Science.gov (United States)

Kasper, Justin C.; SunRISE Team

2018-06-01

The Sun Radio Interferometer Space Experiment (SunRISE) is a NASA Heliophysics Explorer Mission of Opportunity currently in Phase A. SunRISE is a constellation of spacecraft flying in a 10-km diameter formation and operating as the first imaging radio interferometer in space. The purpose of SunRISE is to reveal critical aspects of solar energetic particle (SEP) acceleration at coronal mass ejections (CMEs) and transport into space by making the first spatially resolved observations of coherent Type II and III radio bursts produced by electrons accelerated at CMEs or released from flares. SunRISE will focus on solar Decametric-Hectometric (DH, 0.1 space before major SEP events, but cannot be seen on Earth due to ionospheric absorption. This talk will describe SunRISE objectives and implementation. Presented on behalf of the entire SunRISE team.

Development of an Experimental Testbed for Research in Lithium-Ion Battery Management Systems

Directory of Open Access Journals (Sweden)

Mehdi Ferdowsi

2013-10-01

Full Text Available Advanced electrochemical batteries are becoming an integral part of a wide range of applications from household and commercial to smart grid, transportation, and aerospace applications. Among different battery technologies, lithium-ion (Li-ion batteries are growing more and more popular due to their high energy density, high galvanic potential, low self-discharge, low weight, and the fact that they have almost no memory effect. However, one of the main obstacles facing the widespread commercialization of Li-ion batteries is the design of reliable battery management systems (BMSs. An efficient BMS ensures electrical safety during operation, while increasing battery lifetime, capacity and thermal stability. Despite the need for extensive research in this field, the majority of research conducted on Li-ion battery packs and BMS are proprietary works conducted by manufacturers. The available literature, however, provides either general descriptions or detailed analysis of individual components of the battery system, and ignores addressing details of the overall system development. This paper addresses the development of an experimental research testbed for studying Li-ion batteries and their BMS design. The testbed can be configured in a variety of cell and pack architectures, allowing for a wide range of BMS monitoring, diagnostics, and control technologies to be tested and analyzed. General considerations that should be taken into account while designing Li-ion battery systems are reviewed and different technologies and challenges commonly encountered in Li-ion battery systems are investigated. This testbed facilitates future development of more practical and improved BMS technologies with the aim of increasing the safety, reliability, and efficiency of existing Li-ion battery systems. Experimental results of initial tests performed on the system are used to demonstrate some of the capabilities of the developed research testbed. To the authors�

RSS SSM/I OCEAN PRODUCT GRIDS 3-DAY AVERAGE FROM DMSP F14 NETCDF V7

Data.gov (United States)

National Aeronautics and Space Administration — This dataset is part of the collection of Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Sounder (SSMIS) data products produced as part...

An Overview of NASA's Subsonic Research Aircraft Testbed (SCRAT)

Science.gov (United States)

Baumann, Ethan; Hernandez, Joe; Ruhf, John C.

2013-01-01

National Aeronautics and Space Administration Dryden Flight Research Center acquired a Gulfstream III (GIII) aircraft to serve as a testbed for aeronautics flight research experiments. The aircraft is referred to as SCRAT, which stands for SubsoniC Research Aircraft Testbed. The aircraft's mission is to perform aeronautics research; more specifically raising the Technology Readiness Level (TRL) of advanced technologies through flight demonstrations and gathering high-quality research data suitable for verifying the technologies, and validating design and analysis tools. The SCRAT has the ability to conduct a range of flight research experiments throughout a transport class aircraft's flight envelope. Experiments ranging from flight-testing of a new aircraft system or sensor to those requiring structural and aerodynamic modifications to the aircraft can be accomplished. The aircraft has been modified to include an instrumentation system and sensors necessary to conduct flight research experiments along with a telemetry capability. An instrumentation power distribution system was installed to accommodate the instrumentation system and future experiments. An engineering simulation of the SCRAT has been developed to aid in integrating research experiments. A series of baseline aircraft characterization flights has been flown that gathered flight data to aid in developing and integrating future research experiments. This paper describes the SCRAT's research systems and capabilities.

Design of a speed meter interferometer proof-of-principle experiment

International Nuclear Information System (INIS)

Gräf, C; Barr, B W; Bell, A S; Campbell, F; Cumming, A V; Gordon, N A; Hammond, G D; Hennig, J; Houston, E A; Huttner, S H; Jones, R A; Leavey, S S; Macarthur, J; Marwick, M; Rigby, S; Sorazu, B; Spencer, A; Danilishin, S L; Lück, H; Schilling, R

2014-01-01

The second generation of large scale interferometric gravitational wave (GW) detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of development are being pursued to reach this goal, focusing both on modifications of the well-established Michelson detector configuration and development of different detector topologies. In this paper, we present the design of the world's first Sagnac speed meter (SSM) interferometer, which is currently being constructed at the University of Glasgow. With this proof-of-principle experiment we aim to demonstrate the theoretically predicted lower quantum noise in a Sagnac interferometer compared to an equivalent Michelson interferometer, to qualify SSM for further research towards an implementation in a future generation large scale GW detector, such as the planned Einstein telescope observatory. (paper)

Optimum design of a microwave interferometer for plasma density measurement

International Nuclear Information System (INIS)

Lindberg, L.; Eriksson, A.

1980-11-01

Theoretical and practical problems arising in the application of microwave interferometry to density measurements on transient plasmas are discussed. The conditions for unambiquous measurements in a density range as wide as possible are analyzed. It is shown that the initial zero adjustment of the interferometer bridge recommended in many text books is the worst possible choice of initial condition when the aim is high initial sensitivity at low densities. The analytic expressions needed for unambiquous evaluation of any phase shift from a few degrees to several times π (counting of fringes) are derived. The practical design of the interferometer circuit and its inherent error sources due to reflexions and non-ideal component properties are discussed. The results are applied to an interferometer operating at 80 GHz used on a pulsed plasma experiment. The minimum measurable phase shift is 2deg and the range of linear densities that have been measured is = 1 . 10 16 - 3 . 10 18 m -2

Detection method of nonlinearity errors by statistical signal analysis in heterodyne Michelson interferometer.

Science.gov (United States)

Hu, Juju; Hu, Haijiang; Ji, Yinghua

2010-03-15

Periodic nonlinearity that ranges from tens of nanometers to a few nanometers in heterodyne interferometer limits its use in high accuracy measurement. A novel method is studied to detect the nonlinearity errors based on the electrical subdivision and the analysis method of statistical signal in heterodyne Michelson interferometer. Under the movement of micropositioning platform with the uniform velocity, the method can detect the nonlinearity errors by using the regression analysis and Jackknife estimation. Based on the analysis of the simulations, the method can estimate the influence of nonlinearity errors and other noises for the dimensions measurement in heterodyne Michelson interferometer.

Performance of a 1-micron, 1-joule Coherent Launch Site Atmospheric Wind Sounder

Science.gov (United States)

Hawley, James G.; Targ, Russell; Bruner, Richard; Henderson, Sammy W.; Hale, Charles P.; Vetorino, Steven; Lee, R. W.; Harper, Scott; Khan, Tayyab

1992-01-01

The paper describes the design and performance of the Coherent Launch Site Atmospheric Wind Sounder (CLAWS), which is a test and demonstration program designed for monitoring winds with a solid-state lidar in real time for the launch site vehicle guidance and control application. Analyses were conducted to trade off CO2 (9.11- and 10.6-microns), Ho:YAG (2.09 microns), and Nd:YAG (1.06-micron) laser-based lidars. The measurements set a new altitude record (26 km) for coherent wind measurements in the stratosphere.

Eight-chord CO2 interferometer for plasma-density measurements on ZT-40

International Nuclear Information System (INIS)

Jacobson, A.R.; Jolin, L.J.

1981-01-01

We describe a CO 2 laser interferometer which measures the path-integrated density along eight different chords simultaneously in the ZT-40 reversed-field pinch, a toroidal magnetic confinement experiment at Los Alamos. The interferometer system combines several reliable, commercially available components in a package which provides exceptional measurement resolution as well as ease of operation and maintenance

Genetic Algorithm Phase Retrieval for the Systematic Image-Based Optical Alignment Testbed

Science.gov (United States)

Taylor, Jaime; Rakoczy, John; Steincamp, James

2003-01-01

Phase retrieval requires calculation of the real-valued phase of the pupil fimction from the image intensity distribution and characteristics of an optical system. Genetic 'algorithms were used to solve two one-dimensional phase retrieval problem. A GA successfully estimated the coefficients of a polynomial expansion of the phase when the number of coefficients was correctly specified. A GA also successfully estimated the multiple p h e s of a segmented optical system analogous to the seven-mirror Systematic Image-Based Optical Alignment (SIBOA) testbed located at NASA s Marshall Space Flight Center. The SIBOA testbed was developed to investigate phase retrieval techniques. Tiphilt and piston motions of the mirrors accomplish phase corrections. A constant phase over each mirror can be achieved by an independent tip/tilt correction: the phase Conection term can then be factored out of the Discrete Fourier Tranform (DFT), greatly reducing computations.

The Whisper Relaxation Sounder onboard Cluster: A Powerful Tool for Space Plasma Diagnosis around the Earth

International Nuclear Information System (INIS)

Trotignon, J.G.; Decreau, P.M.E.; Rauch, J.L.; LeGuirriec, E.; Canu, P.; Darrouzet, F.

2001-01-01

The WHISPER relaxation sounder that is onboard the four CLUSTER spacecraft has for main scientific objectives to monitor the natural waves in the 2 kHz - 80 kHz frequency range and, mostly, to determine the total plasma density from the solar wind down to the Earth's plasmasphere. To fulfil these objectives, the WHISPER uses the two long double sphere antennae of the Electric Field and Wave experiment as transmitting and receiving sensors. In its active working mode, the WHISPER works according to principles that have been worked out for topside sounding. A radio wave transmitter sends an almost monochromatic and short wave train. A few milliseconds after, a receiver listens to the surrounding plasma response. Strong and long lasting echoes are actually received whenever the transmitting frequencies coincide with characteristic plasma frequencies. Provided that these echoes, also called resonances, may be identified, the WHISPER relaxation sounder becomes a reliable and powerful tool for plasma diagnosis. When the transmitter is off, the WHISPER behaves like a passive receiver, allowing natural waves to be monitored. The paper aims mainly at the resonance identification process description and the WHISPER capabilities and performance highlighting. (author)

Design and Prototyping of a Satellite Antenna Slew Testbed

Science.gov (United States)

2013-12-01

beers and kind advice gave me a family away from home. To my familia here in the Bay Area; their constant support, understanding and surprise...Encoder Cable Maxon 275934 2 CAB 29 EPOS Power Cable Maxon 275829 2 CAB 30 Misc Hardware** NPS 30 - - Bill of Materials 35 closely match the actual ...computed trajectory. The position and velocity results were then implemented on the testbed motors for comparison of actual versus commanded values

Sagnac interferometer as a speed-meter-type, quantum-nondemolition gravitational-wave detector

Science.gov (United States)

Chen, Yanbei

2003-06-01

According to quantum measurement theory, “speed meters”—devices that measure the momentum, or speed, of free test masses—are immune to the standard quantum limit (SQL). It is shown that a Sagnac-interferometer gravitational-wave detector is a speed meter and therefore in principle it can beat the SQL by large amounts over a wide band of frequencies. It is shown, further, that, when one ignores optical losses, a signal-recycled Sagnac interferometer with Fabry-Perot arm cavities has precisely the same performance, for the same circulating light power, as the Michelson speed-meter interferometer recently invented and studied by Purdue and the author. The influence of optical losses is not studied, but it is plausible that they be fairly unimportant for the Sagnac interferometer, as for other speed meters. With squeezed vacuum (squeeze factor e-2R=0.1) injected into its dark port, the recycled Sagnac interferometer can beat the SQL by a factor (10)≃3 over the frequency band 10 Hz≲f≲150 Hz using the same circulating power Ic˜820 kW as is to be used by the (quantum limited) second-generation Advanced LIGO interferometers—if other noise sources are made sufficiently small. It is concluded that the Sagnac optical configuration, with signal recycling and squeezed-vacuum injection, is an attractive candidate for third-generation interferometric gravitational-wave detectors (LIGO-III and EURO).

Compensation of non-ideal beam splitter polarization distortion effect in Michelson interferometer

Science.gov (United States)

Liu, Yeng-Cheng; Lo, Yu-Lung; Liao, Chia-Chi

2016-02-01

A composite optical structure consisting of two quarter-wave plates and a single half-wave plate is proposed for compensating for the polarization distortion induced by a non-ideal beam splitter in a Michelson interferometer. In the proposed approach, the optimal orientations of the optical components within the polarization compensator are determined using a genetic algorithm (GA) such that the beam splitter can be treated as a free-space medium and modeled using a unit Mueller matrix accordingly. Two implementations of the proposed polarization controller are presented. In the first case, the compensator is placed in the output arm of Michelson interferometer such that the state of polarization of the interfered output light is equal to that of the input light. However, in this configuration, the polarization effects induced by the beam splitter in the two arms of the interferometer structure cannot be separately addressed. Consequently, in the second case, compensator structures are placed in the Michelson interferometer for compensation on both the scanning and reference beams. The practical feasibility of the proposed approach is introduced by considering a Mueller polarization-sensitive (PS) optical coherence tomography (OCT) structure with three polarization controllers in the input, reference and sample arms, respectively. In general, the results presented in this study show that the proposed polarization controller provides an effective and experimentally-straightforward means of compensating for the polarization distortion effects induced by the non-ideal beam splitters in Michelson interferometers and Mueller PS-OCT structures.

Atom Interferometer Technologies in Space for Gravity Mapping and Gravity Science

Science.gov (United States)

Williams, Jason; Chiow, Sheng-Wey; Kellogg, James; Kohel, James; Yu, Nan

2015-05-01

Atom interferometers utilize the wave-nature of atomic gases for precision measurements of inertial forces, with potential applications ranging from gravity mapping for planetary science to unprecedented tests of fundamental physics with quantum gases. The high stability and sensitivity intrinsic to these devices already place them among the best terrestrial sensors available for measurements of gravitational accelerations, rotations, and gravity gradients, with the promise of several orders of magnitude improvement in their detection sensitivity in microgravity. Consequently, multiple precision atom-interferometer-based projects are under development at the Jet Propulsion Laboratory, including a dual-atomic-species interferometer that is to be integrated into the Cold Atom Laboratory onboard the International Space Station and a highly stable gravity gradiometer in a transportable design relevant for earth science measurements. We will present JPL's activities in the use of precision atom interferometry for gravity mapping and gravitational wave detection in space. Our recent progresses bringing the transportable JPL atom interferometer instrument to be competitive with the state of the art and simulations of the expected capabilities of a proposed flight project will also be discussed. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Whisper, a resonance sounder and wave analyser: Performances and perspectives for the Cluster mission

DEFF Research Database (Denmark)

Decreau, P.M.E.; Fergeau, P.; KrannoselsKikh, V.

1997-01-01

The WHISPER sounder on the Cluster spacecraft is primarily designed to provide an absolute measurement of the total plasma density within the range 0.2-80 cm(-3). This is achieved by means of a resonance sounding technique which has already proved successful in the regions to be explored. The wav...... in the electron foreshock and solar wind, to investigations about small-scale structures via density and high-frequency emission signatures, and to the analysis of the non-thermal continuum in the magnetosphere....

A Fiber Interferometer for the Magnetized Shock Experiment

International Nuclear Information System (INIS)

Yoo, Christian

2012-01-01

The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory requires remote diagnostics of plasma density. Laser interferometry can be used to determine the line-integrated density of the plasma. A multi-chord heterodyne fiber optic Mach-Zehnder interferometer is being assembled and integrated into the experiment. The advantage of the fiber coupling is that many different view chords can be easily obtained by simply moving transmit and receive fiber couplers. Several such fiber sets will be implemented to provide a time history of line-averaged density for several chords at once. The multiple chord data can then be Abel inverted to provide radially resolved spatial profiles of density. We describe the design and execution of this multiple fiber interferometer.

On-chip Mach-Zehnder interferometer for OCT systems

Science.gov (United States)

van Leeuwen, Ton G.; Akca, Imran B.; Angelou, Nikolaos; Weiss, Nicolas; Hoekman, Marcel; Leinse, Arne; Heideman, Rene G.

2018-04-01

By using integrated optics, it is possible to reduce the size and cost of a bulky optical coherence tomography (OCT) system. One of the OCT components that can be implemented on-chip is the interferometer. In this work, we present the design and characterization of a Mach-Zehnder interferometer consisting of the wavelength-independent splitters and an on-chip reference arm. The Si3N4 was chosen as the material platform as it can provide low losses while keeping the device size small. The device was characterized by using a home-built swept source OCT system. A sensitivity value of 83 dB, an axial resolution of 15.2 μm (in air) and a depth range of 2.5 mm (in air) were all obtained.

Design of a low-power testbed for Wireless Sensor Networks and verification

NARCIS (Netherlands)

van Hoesel, L.F.W.; Dulman, S.O.; Havinga, Paul J.M.; Kip, Harry J.

In this document the design considerations and component choices of a testbed prototype device for wireless sensor networks will be discussed. These devices must be able to monitor their physical environment, process data and assist other nodes in forwarding sensor readings. For these tasks, five

Atomic interferometers in an optical lattice

International Nuclear Information System (INIS)

Pelle, Bruno

2013-01-01

The aim of the ForCa-G project, for Casimir force and short range Gravitation, lies into the measurement of short range forces between atoms and a mirror using atomic interferometry techniques. Particularly, the Casimir-Polder force and the pursuit of short range gravitational tests in the frame of potential deviations of Newton's law are aimed. This experiment is based on the trapping of neutral atoms in a 1D vertical optical lattice, where the energy eigenvalues of the Hamiltonian describing this system is the so-called Wannier-Stark ladder of discrete energy states localized in each lattice well. This work constitutes a demonstration of principle of this project with atoms set far from the mirror. Each energy state is thus separated from the one of the adjacent well by the potential energy increment between those two wells, called the Bloch frequency ν B . Then, atomic interferometers are realized in the lattice using Raman or microwave pulses where the trapped atomic wave functions are placed, and then recombined, in a superposition of states between different energy states localized either in the same well, either in adjacent wells. This work presents the study of different kinds of atomic interferometers in this optical lattice, characterized in terms of sensibility and systematic effects on the Bloch frequency measurement. One of the studied interferometers accessed to a sensitivity on the Bloch frequency of σ δ ν B /ν B =9.0x10 -6 at 1∼s in relative, which integrates until σ δ ν B /ν B =1. 10 -7 in 2800∼s. This corresponds to a state-of-the-art measurement of the gravity acceleration g for a trapped atomic gravimeter. (author)

TESTING THE APODIZED PUPIL LYOT CORONAGRAPH ON THE LABORATORY FOR ADAPTIVE OPTICS EXTREME ADAPTIVE OPTICS TESTBED

International Nuclear Information System (INIS)

Thomas, Sandrine J.; Dillon, Daren; Gavel, Donald; Soummer, Remi; Macintosh, Bruce; Sivaramakrishnan, Anand

2011-01-01

We present testbed results of the Apodized Pupil Lyot Coronagraph (APLC) at the Laboratory for Adaptive Optics (LAO). These results are part of the validation and tests of the coronagraph and of the Extreme Adaptive Optics (ExAO) for the Gemini Planet Imager (GPI). The apodizer component is manufactured with a halftone technique using black chrome microdots on glass. Testing this APLC (like any other coronagraph) requires extremely good wavefront correction, which is obtained to the 1 nm rms level using the microelectricalmechanical systems (MEMS) technology, on the ExAO visible testbed of the LAO at the University of Santa Cruz. We used an APLC coronagraph without central obstruction, both with a reference super-polished flat mirror and with the MEMS to obtain one of the first images of a dark zone in a coronagraphic image with classical adaptive optics using a MEMS deformable mirror (without involving dark hole algorithms). This was done as a complementary test to the GPI coronagraph testbed at American Museum of Natural History, which studied the coronagraph itself without wavefront correction. Because we needed a full aperture, the coronagraph design is very different from the GPI design. We also tested a coronagraph with central obstruction similar to that of GPI. We investigated the performance of the APLC coronagraph and more particularly the effect of the apodizer profile accuracy on the contrast. Finally, we compared the resulting contrast to predictions made with a wavefront propagation model of the testbed to understand the effects of phase and amplitude errors on the final contrast.

The Visual Orbit and Evolutionary State of 12 Bootes

Science.gov (United States)

Boden, A.; Creech-Eakman, M.; Queloz, D.

1999-01-01

Herein we report the determination of the 12 Boo visual orbit from near-infrared, long-baseline interferometric measurements taken with the Palomar Testbed Interferometer (PTI). We further add photometric and spectroscopic measurements in an attempt to understand the fundamental stellar parameters and evolution of the 12 Boo components.

AMI: Augmented Michelson Interferometer

Science.gov (United States)

Furió, David; Hachet, Martin; Guillet, Jean-Paul; Bousquet, Bruno; Fleck, Stéphanie; Reuter, Patrick; Canioni, Lionel

2015-10-01

Experiments in optics are essential for learning and understanding physical phenomena. The problem with these experiments is that they are generally time consuming for both their construction and their maintenance, potentially dangerous through the use of laser sources, and often expensive due to high technology optical components. We propose to simulate such experiments by way of hybrid systems that exploit both spatial augmented reality and tangible interaction. In particular, we focus on one of the most popular optical experiments: the Michelson interferometer. In our approach, we target a highly interactive system where students are able to interact in real time with the Augmented Michelson Interferometer (AMI) to observe, test hypotheses and then to enhance their comprehension. Compared to a fully digital simulation, we are investigating an approach that benefits from both physical and virtual elements, and where the students experiment by manipulating 3D-printed physical replicas of optical components (e.g. lenses and mirrors). Our objective is twofold. First, we want to ensure that the students will learn with our simulator the same concepts and skills that they learn with traditional methods. Second, we hypothesis that such a system opens new opportunities to teach optics in a way that was not possible before, by manipulating concepts beyond the limits of observable physical phenomena. To reach this goal, we have built a complementary team composed of experts in the field of optics, human-computer interaction, computer graphics, sensors and actuators, and education science.

An X-ray BBB Michelson interferometer.

Science.gov (United States)

Sutter, John P; Ishikawa, Tetsuya; Kuetgens, Ulrich; Materlik, Gerhard; Nishino, Yoshinori; Rostomyan, Armen; Tamasaku, Kenji; Yabashi, Makina

2004-09-01

A new X-ray Michelson interferometer based on the BBB interferometer of Bonse and Hart and designed for X-rays of wavelength approximately 1 A was described in a previous paper. Here, a further test carried out at the SPring-8 1 km beamline BL29XUL is reported. One of the BBB's mirrors was displaced by a piezo to introduce the required path-length difference. The resulting variation of intensity with piezo voltage as measured by an avalanche photodiode could be ascribed to the phase variation resulting from the path-length change, with a small additional contribution from the change of the position of the lattice planes of the front mirror relative to the rest of the crystal. This 'Michelson fringe' interpretation is supported by the observed steady movement across the output beam of the interference fringes produced by a refractive wedge when the piezo voltage was ramped. The front-mirror displacement required for one complete fringe at the given wavelength is only 0.675 A; therefore, a quiet environment is vital for operating this device, as previous experiments have shown.

Testbed model and data assimilation for ARM

International Nuclear Information System (INIS)

Louis, J.F.

1992-01-01

The objectives of this contract are to further develop and test the ALFA (AER Local Forecast and Assimilation) model originally designed at AER for local weather prediction and apply it to three distinct but related purposes in connection with the Atmospheric Radiation Measurement (ARM) program: (a) to provide a testbed that simulates a global climate model in order to facilitate the development and testing of new cloud parametrizations and radiation models; (b) to assimilate the ARM data continuously at the scale of a climate model, using the adjoint method, thus providing the initial conditions and verification data for testing parameumtions; (c) to study the sensitivity of a radiation scheme to cloud parameters, again using the adjoint method, thus demonstrating the usefulness of the testbed model. The data assimilation will use a variational technique that minimizes the difference between the model results and the observation during the analysis period. The adjoint model is used to compute the gradient of a measure of the model errors with respect to nudging terms that are added to the equations to force the model output closer to the data. The radiation scheme that will be included in the basic ALFA model makes use of a gen two-stream approximation, and is designed for vertically inhonogeneous, multiple-scattering atmospheres. The sensitivity of this model to the definition of cloud parameters will be studied. The adjoint technique will also be used to compute the sensitivities. This project is designed to provide the Science Team members with the appropriate tools and modeling environment for proper testing and tuning of new radiation models and cloud parametrization schemes

Carbon Monoxide Distribution over Peninsular Malaysia from the Atmospheric Infrared Sounder (AIRS)

Science.gov (United States)

Rajab, Jaso M.; MatJafri, M. Z.; Lim, H. S.; Abdullah, K.

2009-07-01

The Atmospheric Infrared Sounder (AIRS) onboard NASA's Aqua satellite. It daily coverage of ˜70% of the planet represents a significant evolutionary advance in satellite traces gas remote sensing. AIRS, the part of a large international investment to upgrade the operational meteorological satellite systems, is first of the new generation of meteorological advanced sounders for operational and research use, Providing New Insights into Weather and Climate for the 21st Century. Carbon monoxide (CO) is a ubiquitous, an indoor and outdoor air pollutant, is not a significant greenhouse gas as it absorbs little infrared radiation from the Earth. However, it does have an influence on oxidization in the atmosphere through interaction with hydroxyl radicals (OH), which also react with methane, halocarbons and tropospheric ozone. It produced by the incomplete combustion of fossil fuels and biomass burning, and that it has a role as a smog. The aim of this investigation is to study the (CO) carbon monoxide distribution over Peninsular Malaysia. The land use map of the Peninsular Malaysia was conducted by using CO total column amount, obtained from AIRS data, the map & data was processed and analyzed by using Photoshop & SigmaPlot 11.0 programs and compared for timing of various (day time) (28 August 2005 & 29 August 2007) for both direct comparison and the comparison using the same a priori profile, the CO concentrations in 28/8/2005 higher. The CO maps were generated using Kriging Interpolation technique. This interpolation technique produced high correlation coefficient, R2 and low root mean square error, RMS for CO. This study provided useful information for influence change of CO concentration on varies temperature.

Density Measurement of Compact Toroid with Mach-Zehnder Interferometer

Science.gov (United States)

Laufman-Wollitzer, Lauren; Endrizzi, Doug; Brookhart, Matt; Flanagan, Ken; Forest, Cary

2016-10-01

Utilizing a magnetized coaxial plasma gun (MCPG) built by Tri Alpha Energy, a dense compact toroid (CT) is created and injected at high speed into the Wisconsin Plasma Astrophysics Laboratory (WiPAL) vessel. A modified Mach-Zehnder interferometer from the Line-Tied Reconnection Experiment (LTRX) provides an absolute measurement of electron density. The interferometer is located such that the beam intersects the plasma across the diameter of the MCPG drift region before the CT enters the vessel. This placement ensures that the measurement is taken before the CT expand. Results presented will be used to further analyze characteristics of the CT. Funding provided by DoE, NSF, and WISE Summer Research.

A reconfigurable optofluidic Michelson interferometer using tunable droplet grating.

Science.gov (United States)

Chin, L K; Liu, A Q; Soh, Y C; Lim, C S; Lin, C L

2010-04-21

This paper presents a novel optofluidic Michelson interferometer based on droplet microfluidics used to create a droplet grating. The droplet grating is formed by a stream of plugs in the microchannel with constant refractive index variation. It has a real-time tunability in the grating period through varying the flow rates of the liquids and index variation via different combinations of liquids. The optofluidic Michelson interferometer is highly sensitive and is suitable for the measurement of biomedical and biochemical buffer solutions. The experimental results show that it has a sensitivity of 66.7 nm per refractive index unit (RIU) and a detection range of 0.086 RIU.

Detecting a stochastic gravitational wave background with the Laser Interferometer Space Antenna

International Nuclear Information System (INIS)

Cornish, Neil J.

2002-01-01

The random superposition of many weak sources will produce a stochastic background of gravitational waves that may dominate the response of the LISA (Laser Interferometer Space Antenna) gravitational wave observatory. Unless something can be done to distinguish between a stochastic background and detector noise, the two will combine to form an effective noise floor for the detector. Two methods have been proposed to solve this problem. The first is to cross-correlate the output of two independent interferometers. The second is an ingenious scheme for monitoring the instrument noise by operating LISA as a Sagnac interferometer. Here we derive the optimal orbital alignment for cross-correlating a pair of LISA detectors, and provide the first analytic derivation of the Sagnac sensitivity curve

Analysis of a micropolarizer array-based simultaneous phase-shifting interferometer.

Science.gov (United States)

Novak, Matt; Millerd, James; Brock, Neal; North-Morris, Michael; Hayes, John; Wyant, James

2005-11-10

Recent technological innovations have enabled the development of a new class of dynamic (vibration-insensitive) interferometer based on a CCD pixel-level phase-shifting approach. We present theoretical and experimental results for an interferometer based on this pixelated phase-shifting technique. Analyses of component errors and instrument functionality are presented. We show that the majority of error sources cause relatively small magnitude peak-to-valley errors in measurement of the order of 0.002-0.005lambda. These errors are largely mitigated by high-rate data acquisition and consequent data averaging.

Herriott Cell Augmentation of a Quadrature Heterodyne Interferometer

National Research Council Canada - National Science Library

Antonsen, Erik

2002-01-01

A quadrature heterodyne interferometer is augmented with a Herriott Cell multi-pass reflector to increase instrument resolution and enable a separation of the phase shift due to neutral density from room vibrations...

Design, Development, and Testing of a UAV Hardware-in-the-Loop Testbed for Aviation and Airspace Prognostics Research

Science.gov (United States)

Kulkarni, Chetan; Teubert, Chris; Gorospe, George; Burgett, Drew; Quach, Cuong C.; Hogge, Edward

2016-01-01

The airspace is becoming more and more complicated, and will continue to do so in the future with the integration of Unmanned Aerial Vehicles (UAVs), autonomy, spacecraft, other forms of aviation technology into the airspace. The new technology and complexity increases the importance and difficulty of safety assurance. Additionally, testing new technologies on complex aviation systems & systems of systems can be very difficult, expensive, and sometimes unsafe in real life scenarios. Prognostic methodology provides an estimate of the health and risks of a component, vehicle, or airspace and knowledge of how that will change over time. That measure is especially useful in safety determination, mission planning, and maintenance scheduling. The developed testbed will be used to validate prediction algorithms for the real-time safety monitoring of the National Airspace System (NAS) and the prediction of unsafe events. The framework injects flight related anomalies related to ground systems, routing, airport congestion, etc. to test and verify algorithms for NAS safety. In our research work, we develop a live, distributed, hardware-in-the-loop testbed for aviation and airspace prognostics along with exploring further research possibilities to verify and validate future algorithms for NAS safety. The testbed integrates virtual aircraft using the X-Plane simulator and X-PlaneConnect toolbox, UAVs using onboard sensors and cellular communications, and hardware in the loop components. In addition, the testbed includes an additional research framework to support and simplify future research activities. It enables safe, accurate, and inexpensive experimentation and research into airspace and vehicle prognosis that would not have been possible otherwise. This paper describes the design, development, and testing of this system. Software reliability, safety and latency are some of the critical design considerations in development of the testbed. Integration of HITL elements in

Search for a stochastic background of 100-MHz gravitational waves with laser interferometers.

Science.gov (United States)

Akutsu, Tomotada; Kawamura, Seiji; Nishizawa, Atsushi; Arai, Koji; Yamamoto, Kazuhiro; Tatsumi, Daisuke; Nagano, Shigeo; Nishida, Erina; Chiba, Takeshi; Takahashi, Ryuichi; Sugiyama, Naoshi; Fukushima, Mitsuhiro; Yamazaki, Toshitaka; Fujimoto, Masa-Katsu

2008-09-05

This Letter reports the results of a search for a stochastic background of gravitational waves (GW) at 100 MHz by laser interferometry. We have developed a GW detector, which is a pair of 75-cm baseline synchronous recycling (resonant recycling) interferometers. Each interferometer has a strain sensitivity of approximately 10;{-16} Hz;{-1/2} at 100 MHz. By cross-correlating the outputs of the two interferometers within 1000 seconds, we found h{100};{2}Omega_{gw}<6 x 10;{25} to be an upper limit on the energy density spectrum of the GW background in a 2-kHz bandwidth around 100 MHz, where a flat spectrum is assumed.

Interferometer for Measuring Fast Changes of Refractive Index and Temperature in Transparent Liquids

DEFF Research Database (Denmark)

Miller, Arne; Hussmann, E. K.; McLaughlin, W. L.

1975-01-01

A double‐beam interferometer has been designed for detecting changes of refractive index in transparent liquids associated with the absorption of ionizing radiation energy, due to short electron beam pulses from an accelerator. The response time of the interferometer is less than 0.2 μsec......, and refractive index changes of the order of 10−7 can be measured, corresponding to a temperature change of ∼10−3  °C and an absorbed dose in water of ∼350 rad. The interferometer can be used as either a real‐time or integrating radiation dosimeter, if the temperature coefficient of the refractive index (dn...

Broadband squeezing of quantum noise in a Michelson interferometer with Twin-Signal-Recycling.

Science.gov (United States)

Thüring, André; Gräf, Christian; Vahlbruch, Henning; Mehmet, Moritz; Danzmann, Karsten; Schnabel, Roman

2009-03-15

Twin-Signal-Recycling (TSR) builds on the resonance doublet of two optically coupled cavities and efficiently enhances the sensitivity of an interferometer at a dedicated signal frequency. We report on what we believe to be the first experimental realization of a TSR Michelson interferometer and also its broadband enhancement by squeezed light injection. The complete setup was stably locked, and a broadband quantum noise reduction of the interferometers shot noise by a factor of up to 4 dB was demonstrated. The system was characterized by measuring its quantum noise spectra for several tunings of the TSR cavities. We found good agreement between the experimental results and numerical simulations.

Interferometers as probes of Planckian quantum geometry

Science.gov (United States)

Hogan, Craig J.

2012-03-01

A theory of position of massive bodies is proposed that results in an observable quantum behavior of geometry at the Planck scale, tP. Departures from classical world lines in flat spacetime are described by Planckian noncommuting operators for position in different directions, as defined by interactions with null waves. The resulting evolution of position wave functions in two dimensions displays a new kind of directionally coherent quantum noise of transverse position. The amplitude of the effect in physical units is predicted with no parameters, by equating the number of degrees of freedom of position wave functions on a 2D space-like surface with the entropy density of a black hole event horizon of the same area. In a region of size L, the effect resembles spatially and directionally coherent random transverse shear deformations on time scale ≈L/c with typical amplitude ≈ctPL. This quantum-geometrical “holographic noise” in position is not describable as fluctuations of a quantized metric, or as any kind of fluctuation, dispersion or propagation effect in quantum fields. In a Michelson interferometer the effect appears as noise that resembles a random Planckian walk of the beam splitter for durations up to the light-crossing time. Signal spectra and correlation functions in interferometers are derived, and predicted to be comparable with the sensitivities of current and planned experiments. It is proposed that nearly colocated Michelson interferometers of laboratory scale, cross-correlated at high frequency, can test the Planckian noise prediction with current technology.

Combined shearing interferometer and hartmann wavefront sensor

International Nuclear Information System (INIS)

Hutchin, R. A.

1985-01-01

A sensitive wavefront sensor combining attributes of both a Hartmann type of wavefront sensor and an AC shearing interferometer type of wavefront sensor. An incident wavefront, the slope of which is to be detected, is focussed to first and second focal points at which first and second diffraction gratings are positioned to shear and modulate the wavefront, which then diverges therefrom. The diffraction patterns of the first and second gratings are positioned substantially orthogonal to each other to shear the wavefront in two directions to produce two dimensional wavefront slope data for the AC shearing interferometer portion of the wavefront sensor. First and second dividing optical systems are positioned in the two diverging wavefronts to divide the sheared wavefront into an array of subapertures and also to focus the wavefront in each subaperture to a focal point. A quadrant detector is provided for each subaperture to detect the position of the focal point therein, which provides a first indication, in the manner of a Hartmann wavefront sensor, of the local wavefront slope in each subaperture. The total radiation in each subaperture, as modulated by the diffraction grating, is also detected by the quadrant detector which produces a modulated output signal representative thereof, the phase of which relative to modulation by the diffraction grating provides a second indication of the local wavefront slope in each subaperture, in the manner of an AC shearing interferometer wavefront sensor. The data from both types of sensors is then combined by long term averaging thereof to provide an extremely sensitive wavefront sensor

Development of a GPU-based high-performance radiative transfer model for the Infrared Atmospheric Sounding Interferometer (IASI)

International Nuclear Information System (INIS)

Huang Bormin; Mielikainen, Jarno; Oh, Hyunjong; Allen Huang, Hung-Lung

2011-01-01

Satellite-observed radiance is a nonlinear functional of surface properties and atmospheric temperature and absorbing gas profiles as described by the radiative transfer equation (RTE). In the era of hyperspectral sounders with thousands of high-resolution channels, the computation of the radiative transfer model becomes more time-consuming. The radiative transfer model performance in operational numerical weather prediction systems still limits the number of channels we can use in hyperspectral sounders to only a few hundreds. To take the full advantage of such high-resolution infrared observations, a computationally efficient radiative transfer model is needed to facilitate satellite data assimilation. In recent years the programmable commodity graphics processing unit (GPU) has evolved into a highly parallel, multi-threaded, many-core processor with tremendous computational speed and very high memory bandwidth. The radiative transfer model is very suitable for the GPU implementation to take advantage of the hardware's efficiency and parallelism where radiances of many channels can be calculated in parallel in GPUs. In this paper, we develop a GPU-based high-performance radiative transfer model for the Infrared Atmospheric Sounding Interferometer (IASI) launched in 2006 onboard the first European meteorological polar-orbiting satellites, METOP-A. Each IASI spectrum has 8461 spectral channels. The IASI radiative transfer model consists of three modules. The first module for computing the regression predictors takes less than 0.004% of CPU time, while the second module for transmittance computation and the third module for radiance computation take approximately 92.5% and 7.5%, respectively. Our GPU-based IASI radiative transfer model is developed to run on a low-cost personal supercomputer with four GPUs with total 960 compute cores, delivering near 4 TFlops theoretical peak performance. By massively parallelizing the second and third modules, we reached 364x

NOAA Climate Data Record (CDR) of Intersatellite Calibrated Clear-Sky High Resolution Infrared Radiation Sounder (HIRS) Channel 12 Brightness Temperature Version 3

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The High-Resolution Infrared Radiation Sounder (HIRS) of intersatellite calibrated channel 12 brightness temperature (TB) product is a gridded global monthly time...

BEATBOX v1.0: Background Error Analysis Testbed with Box Models

Science.gov (United States)

Knote, Christoph; Barré, Jérôme; Eckl, Max

2018-02-01

The Background Error Analysis Testbed (BEATBOX) is a new data assimilation framework for box models. Based on the BOX Model eXtension (BOXMOX) to the Kinetic Pre-Processor (KPP), this framework allows users to conduct performance evaluations of data assimilation experiments, sensitivity analyses, and detailed chemical scheme diagnostics from an observation simulation system experiment (OSSE) point of view. The BEATBOX framework incorporates an observation simulator and a data assimilation system with the possibility of choosing ensemble, adjoint, or combined sensitivities. A user-friendly, Python-based interface allows for the tuning of many parameters for atmospheric chemistry and data assimilation research as well as for educational purposes, for example observation error, model covariances, ensemble size, perturbation distribution in the initial conditions, and so on. In this work, the testbed is described and two case studies are presented to illustrate the design of a typical OSSE experiment, data assimilation experiments, a sensitivity analysis, and a method for diagnosing model errors. BEATBOX is released as an open source tool for the atmospheric chemistry and data assimilation communities.

BEATBOX v1.0: Background Error Analysis Testbed with Box Models

Directory of Open Access Journals (Sweden)

C. Knote

2018-02-01

Full Text Available The Background Error Analysis Testbed (BEATBOX is a new data assimilation framework for box models. Based on the BOX Model eXtension (BOXMOX to the Kinetic Pre-Processor (KPP, this framework allows users to conduct performance evaluations of data assimilation experiments, sensitivity analyses, and detailed chemical scheme diagnostics from an observation simulation system experiment (OSSE point of view. The BEATBOX framework incorporates an observation simulator and a data assimilation system with the possibility of choosing ensemble, adjoint, or combined sensitivities. A user-friendly, Python-based interface allows for the tuning of many parameters for atmospheric chemistry and data assimilation research as well as for educational purposes, for example observation error, model covariances, ensemble size, perturbation distribution in the initial conditions, and so on. In this work, the testbed is described and two case studies are presented to illustrate the design of a typical OSSE experiment, data assimilation experiments, a sensitivity analysis, and a method for diagnosing model errors. BEATBOX is released as an open source tool for the atmospheric chemistry and data assimilation communities.

Explosive component acceptance tester using laser interferometer technology

Science.gov (United States)

Wickstrom, Richard D.; Tarbell, William W.

1993-01-01

Acceptance testing of explosive components requires a reliable and simple to use testing method that can discern less than optimal performance. For hot-wire detonators, traditional techniques use dent blocks or photographic diagnostic methods. More complicated approaches are avoided because of their inherent problems with setup and maintenance. A recently developed tester is based on using a laser interferometer to measure the velocity of flying plates accelerated by explosively actuated detonators. Unlike ordinary interferometers that monitor displacement of the test article, this device measures velocity directly and is commonly used with non-spectral surfaces. Most often referred to as the VISAR technique (Velocity Interferometer System for Any Reflecting Surface), it has become the most widely-accepted choice for accurate measurement of velocity in the range greater than 1 mm/micro-s. Traditional VISAR devices require extensive setup and adjustment and therefore are unacceptable in a production-testing environment. This paper describes a new VISAR approach which requires virtually no adjustments, yet provides data with accuracy comparable to the more complicated systems. The device, termed the Fixed-Cavity VISAR, is currently being developed to serve as a product verification tool for hot-wire detonators and slappers. An extensive data acquisition and analysis computer code was also created to automate the manipulation of raw data into final results.

A commercial space technology testbed on ISS

Science.gov (United States)

Boyle, David R.

2000-01-01

There is a significant and growing commercial market for new, more capable communications and remote sensing satellites. Competition in this market strongly motivates satellite manufacturers and spacecraft component developers to test and demonstrate new space hardware in a realistic environment. External attach points on the International Space Station allow it to function uniquely as a space technology testbed to satisfy this market need. However, space industry officials have identified three critical barriers to their commercial use of the ISS: unpredictable access, cost risk, and schedule uncertainty. Appropriate NASA policy initiatives and business/technical assistance for industry from the Commercial Space Center for Engineering can overcome these barriers. .

A technical description of the FlexHouse Project Testbed

DEFF Research Database (Denmark)

Sørensen, Jens Otto

2000-01-01

This paper describes the FlexHouse project testbed; a server dedicated to experiments within the FlexHouse project. The FlexHouse project is a project originating from The Business Computing Research Group at The Aarhus School of Business. The purpose of the project is to identify and develop...... methods that satisfy the following three requirements. Flexibility with respect to evolving data sources. Flexibility with respect to change of information needs. Efficiency with respect to view management....

Testbed for a LiFi system integrated in streetlights

OpenAIRE

Monzón Baeza, Victor; Sánchez Fernández, Matilde Pilar; García-Armada, Ana; Royo, A.

2015-01-01

Proceeding at: 2015 European Conference on Networks and Communications (EuCNC) took place June 29 - July 2 in Paris, France. In this paper, a functional LiFi real-time testbed implemented on FPGAs is presented. The setup evaluates the performance of our design in a downlink scenario where the transmitter is embedded on the streetlights and a mobile phone’s camera is used as receiver, therefore achieving the goal of lighting and communicating simultaneously. To validate the ...

Erbium-doped fiber ring laser with SMS modal interferometer for hydrogen sensing

Science.gov (United States)

Zhang, Ya-nan; Zhang, Lebin; Han, Bo; Peng, Huijie; Zhou, Tianmin; Lv, Ri-qing

2018-06-01

A hydrogen sensor based on erbium-doped fiber ring laser with modal interferometer is proposed. A single mode-multimode-single mode (SMS) modal interferometer structure coated with Pd/WO3 film is used as the sensing head, due to that it is easy to be fabricated and low cost. The sensing structure is inserted into an erbium-doped fiber ring laser in order to solve the problem of spectral confusion and improve the detection limit of the hydrogen sensor based on the SMS modal interferometer. The SMS sensing structure is acted as a fiber band-pass filter. When hydrogen concentration around the sensor is changed, it will induce the refractive index and strain variations of the Pd/WO3 film, and then shift the resonant spectrum of the SMS modal interferometer as well as the laser wavelength of the fiber ring laser. Therefore, the hydrogen concentration can be measured by monitoring the wavelength shift of the laser, which has high intensity and narrow full width half maximum. Experimental results demonstrate that the sensor has high sensitivity of 1.23 nm/%, low detection limit of 0.017%, good stability and excellent repeatability.

Background reduction in a young interferometer biosensor

NARCIS (Netherlands)

Mulder, H. K P; Subramaniam, V.; Kanger, J. S.

2014-01-01

Integrated optical Young interferometer (IOYI) biosensors are among the most sensitive label-free biosensors. Detection limits are in the range of 20 fg/mm2. The applicability of these sensors is however strongly hampered by the large background that originates from both bulk refractive index

Analysis, Modeling, and Simulation (AMS) Testbed Development and Evaluation to Support Dynamic Mobility Applications (DMA) and Active Transportation and Demand Management (ATDM) Programs : Evaluation Report for the San Diego Testbed : Draft Report.

Science.gov (United States)

2017-07-01

The primary objective of this project is to develop multiple simulation testbeds and transportation models to evaluate the impacts of Connected Vehicle Dynamic Mobility Applications (DMA) and Active Transportation and Demand Management (ATDM) strateg...

PlanetLab Europe as Geographically-Distributed Testbed for Software Development and Evaluation

Directory of Open Access Journals (Sweden)

Dan Komosny

2015-01-01

Full Text Available In this paper, we analyse the use of PlanetLab Europe for development and evaluation of geographically-oriented Internet services. PlanetLab is a global research network with the main purpose to support development of new Internet services and protocols. PlanetLab is divided into several branches; one of them is PlanetLab Europe. PlanetLab Europe consists of about 350 nodes at 150 geographically different sites. The nodes are accessible by remote login, and the users can run their software on the nodes. In the paper, we study the PlanetLab's properties that are significant for its use as a geographically distributed testbed. This includes node position accuracy, services availability and stability. We find a considerable number of location inaccuracies and a number of services that cannot be considered as reliable. Based on the results we propose a simple approach to nodes selection in testbeds for geographically-oriented Internet services development and evaluation.

Operational experience with synchrotron light interferometers for CEBAF experimental beam lines

Energy Technology Data Exchange (ETDEWEB)

Pavel Chevtsov

2006-10-24

Beam size and energy spread monitoring systems based on Synchrotron Light Interferometers (SLI) have been in operations at Jefferson Lab for several years. A non-invasive nature and a very high (a few mm) resolution of SLI make these instruments valuable beam diagnostic tools for the CEBAF accelerator. This presentation describes the evolution of the Synchrotron Light Interferometer at Jefferson Lab and highlights our extensive experience in the installation and operation of the SLI for CEBAF experimental beam lines.

Preliminary result of bunch length measurement using a modified Michelson interferometer

International Nuclear Information System (INIS)

Lin Xuling; Luo Feng; Bei Hua; Dai Zhimin; Chinese Academy of Sciences, Beijing; Zhang Jianbing; Lu Shanliang; Yu Tiemin

2009-01-01

Based on the femtosecond accelerator device which was built at the Shanghai Institute of Applied Physics (SINAP), recently a modified far infrared Michelson interferometer has been developed to measure the length of electron bunches via the optical autocorrelation method. Compared with our former normal Michelson interferometer, we use a hollow retroreflector instead of a flat mirror as the reflective mirror. The experimental setup and results of the bunch length measurement will be described in this paper. (authors)

Sensing across large-scale cognitive radio networks: Data processing, algorithms, and testbed for wireless tomography and moving target tracking

Science.gov (United States)

Bonior, Jason David

As the use of wireless devices has become more widespread so has the potential for utilizing wireless networks for remote sensing applications. Regular wireless communication devices are not typically designed for remote sensing. Remote sensing techniques must be carefully tailored to the capabilities of these networks before they can be applied. Experimental verification of these techniques and algorithms requires robust yet flexible testbeds. In this dissertation, two experimental testbeds for the advancement of research into sensing across large-scale cognitive radio networks are presented. System architectures, implementations, capabilities, experimental verification, and performance are discussed. One testbed is designed for the collection of scattering data to be used in RF and wireless tomography research. This system is used to collect full complex scattering data using a vector network analyzer (VNA) and amplitude-only data using non-synchronous software-defined radios (SDRs). Collected data is used to experimentally validate a technique for phase reconstruction using semidefinite relaxation and demonstrate the feasibility of wireless tomography. The second testbed is a SDR network for the collection of experimental data. The development of tools for network maintenance and data collection is presented and discussed. A novel recursive weighted centroid algorithm for device-free target localization using the variance of received signal strength for wireless links is proposed. The signal variance resulting from a moving target is modeled as having contours related to Cassini ovals. This model is used to formulate recursive weights which reduce the influence of wireless links that are farther from the target location estimate. The algorithm and its implementation on this testbed are presented and experimental results discussed.