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Sample records for advanced infrared sounder

  1. Advanced microwave sounding unit study for atmospheric infrared sounder

    NASA Technical Reports Server (NTRS)

    Rosenkranz, Philip W.; Staelin, David H.

    1992-01-01

    The Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU-A), and the Microwave Humidity Sounder (MHS, formerly AMSU-B) together constitute the advanced sounding system facility for the Earth Observing System (EOS). A summary of the EOS phase B activities are presented.

  2. Geophysical Information from Advanced Sounder Infrared Spectral Radiance

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    Advanced satellite sensors are tasked with improving global observations of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Satisfying this type of improvement for inferred geophysical information from these observations requires optimal usage of data from current systems as well as enhancements to future sensors. This presentation addresses the information content present in infrared spectral radiance from advanced atmospheric sounders with an emphasis on knowledge of thermodynamic state and trace species. Results of trade-off studies conducted to evaluate the impact of spectral resolution, spectral coverage, instrument noise, and a priori knowledge on remote sensing system information content will be discussed. A focus is placed on information achievable from the Atmospheric InfraRed Sounder (AIRS) on the NASA EOS Aqua satellite in orbit since 2002, the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A since 2006, and the Cross-track Infrared Sounder (CrIS) instrument aboard the NPP and JPSS series of satellites which began 28 October 2011.

  3. Assimilation of thermodynamic information from advanced infrared sounders under partially cloudy skies for regional NWP

    NASA Astrophysics Data System (ADS)

    Wang, Pei; Li, Jun; Goldberg, Mitchell D.; Schmit, Timothy J.; Lim, Agnes H. N.; Li, Zhenglong; Han, Hyojin; Li, Jinlong; Ackerman, Steve A.

    2015-06-01

    Generally, only clear-infrared spectral radiances (not affected by clouds) are assimilated in weather analysis systems. This is due to difficulties in modeling cloudy radiances as well as in observing their vertical structure from space. To take full advantage of the thermodynamic information in advanced infrared (IR) sounder observations requires assimilating radiances from cloud-contaminated regions. An optimal imager/sounder cloud-clearing technique has been developed by the Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin-Madison. This technique can be used to retrieve clear column radiances through combining collocated multiband imager IR clear radiances and the sounder cloudy radiances; no background information is needed in this method. The imager/sounder cloud-clearing technique is similar to that of the microwave/IR cloud clearing in the derivation of the clear-sky equivalent radiances. However, it retains the original IR sounder resolution, which is critical for regional numerical weather prediction applications. In this study, we have investigated the assimilation of cloud-cleared IR sounder radiances using Atmospheric Infrared Sounder (AIRS)/Moderate Resolution Imaging Spectroradiometer for three hurricanes, Sandy (2012), Irene (2011), and Ike (2008). Results show that assimilating additional cloud-cleared AIRS radiances reduces the 48 and 72 h temperature forecast root-mean-square error by 0.1-0.3 K between 300 and 850 hPa. Substantial improvement in reducing track forecasts errors in the range of 10 km to 50 km was achieved.

  4. Advanced infrared sounder subpixel cloud detection with imagers and its impact on radiance assimilation in NWP

    NASA Astrophysics Data System (ADS)

    Wang, Pei; Li, Jun; Li, Jinlong; Li, Zhenglong; Schmit, Timothy J.; Bai, Wenguang

    2014-03-01

    Accurate cloud detection is very important for infrared (IR) radiance assimilation; improved cloud detection could reduce cloud contamination and hence improve the assimilation. Although operational numerical weather prediction (NWP) centers are using IR sounder radiance data for cloud detection, collocated high spatial resolution imager data could help sounder subpixel cloud detection and characterization. IR sounder radiances with improved cloud detection using Atmospheric Infrared Sounder (AIRS)/Moderate Resolution Imaging Spectroradiometer (MODIS) were assimilated for Hurricane Sandy (2012). Forecast experiments were run with Weather Research and Forecasting (WRF) as the forecast model and the Three-Dimensional Variational Assimilation (3DVAR)-based Gridpoint Statistical Interpolation (GSI) as the analysis system. Results indicate that forecasts of both hurricane track and intensity are substantially improved when the collocated high spatial resolution MODIS cloud mask is used for AIRS subpixel cloud detection for assimilating radiances. This methodology can be applied to process Crosstrack Infrared Sounder (CRIS)/Visible Infrared Imaging Radiometer Suite (VIIRS) onboard Suomi-NPOESS Preparatory Project (NPP)/Joint Polar Satellite System (JPSS) and Infrared Atmospheric Sounding Interferometer (IASI)/Advanced Very High Resolution Radiometer (AVHRR) onboard the Metop series for improved radiance assimilation in NWP.

  5. Spaceborne Infrared Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas; Macenka, Steven; Kampe, Thomas

    2004-01-01

    A report describes the development of the spaceborne infrared atmospheric sounder (SIRAS) - a spectral imaging instrument, suitable for observing the atmosphere of the Earth from a spacecraft, that utilizes four spectrometers to cover the wavelength range of 12 to 15.4 m with a spectral resolution that ranges between 1 part per 900 and 1 part per 1,200 in wavelength. The spectrometers are operated in low orders to minimize filtering requirements. Focal planes receive the dispersed energy and provide a spectrum of the scene. The design of the SIRAS combines advanced, wide-field refractive optics with high-dispersion gratings in a solid-state (no moving parts), diffraction-limited optical system that is the smallest such system that can be constructed for the specified wavelength range and resolution. The primary structure of the SIRAS has dimensions of 10 by 10 by 14 cm and has a mass of only 2.03 kg

  6. Atmospheric infrared sounder

    NASA Technical Reports Server (NTRS)

    Rosenkranz, Philip, W.; Staelin, David, H.

    1995-01-01

    This report summarizes the activities of two Atmospheric Infrared Sounder (AIRS) team members during the first half of 1995. Changes to the microwave first-guess algorithm have separated processing of Advanced Microwave Sounding Unit A (AMSU-A) from AMSU-B data so that the different spatial resolutions of the two instruments may eventually be considered. Two-layer cloud simulation data was processed with this algorithm. The retrieved water vapor column densities and liquid water are compared. The information content of AIRS data was applied to AMSU temperature profile retrievals in clear and cloudy atmospheres. The significance of this study for AIRS/AMSU processing lies in the improvement attributable to spatial averaging and in the good results obtained with a very simple algorithm when all of the channels are used. Uncertainty about the availability of either a Microwave Humidity Sensor (MHS) or AMSU-B for EOS has motivated consideration of possible low-cost alternative designs for a microwave humidity sensor. One possible configuration would have two local oscillators (compared to three for MHS) at 118.75 and 183.31 GHz. Retrieval performances of the two instruments were compared in a memorandum titled 'Comparative Analysis of Alternative MHS Configurations', which is attached.

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

    NASA Technical Reports Server (NTRS)

    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.

  8. Biases in Total Precipitable Water Vapor Climatologies from Atmospheric Infrared Sounder and Advanced Microwave Scanning Radiometer

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Eldering, Annmarie; Aumann, Hartmut H.; Chahine, Moustafa T.

    2006-01-01

    We examine differences in total precipitable water vapor (PWV) from the Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Scanning Radiometer (AMSR-E) experiments sharing the Aqua spacecraft platform. Both systems provide estimates of PWV over water surfaces. We compare AIRS and AMSR-E PWV to constrain AIRS retrieval uncertainties as functions of AIRS retrieved infrared cloud fraction. PWV differences between the two instruments vary only weakly with infrared cloud fraction up to about 70%. Maps of AIRS-AMSR-E PWV differences vary with location and season. Observational biases, when both instruments observe identical scenes, are generally less than 5%. Exceptions are in cold air outbreaks where AIRS is biased moist by 10-20% or 10-60% (depending on retrieval processing) and at high latitudes in winter where AIRS is dry by 5-10%. Sampling biases, from different sampling characteristics of AIRS and AMSR-E, vary in sign and magnitude. AIRS sampling is dry by up to 30% in most high-latitude regions but moist by 5-15% in subtropical stratus cloud belts. Over the northwest Pacific, AIRS samples conditions more moist than AMSR-E by a much as 60%. We hypothesize that both wet and dry sampling biases are due to the effects of clouds on the AIRS retrieval methodology. The sign and magnitude of these biases depend upon the types of cloud present and on the relationship between clouds and PWV. These results for PWV imply that climatologies of height-resolved water vapor from AIRS must take into consideration local meteorological processes affecting AIRS sampling.

  9. AIRS - the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Lambrigsten, Bjorn H.; Fetzer, Eric; Fishbein, Evan; Lee, Sung-Yung; Paganao, Thomas

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) was launched in 2002, along with two companion microwave sounders. This AIRS sounding suite is the most advanced atmospheric sounding system to date, with measurement accuracies far surpassing those of current weather satellites. From its sun synchronous polar orbit, the AIRS system provides more than 90% of the globe every 24 hours. Much of the post-launch period has been devoted to optimizing the 'retrieval' system used to derive atmospheric and other parameters from the observations and to validate those parameters. The geophysical parameters have been produced since the beginning of 2003 - the first data were released to the public in mid-2003, and future improved versions will be released periodically. The ongoing calibration/validation effort has confirmed that the system is very accurate and stable. There are a number of applications for the AIRS products, ranging from numerical weather prediction - where positive impact on forecast accuracy has already been demonstrated, to atmospheric research - where the AIRS water vapor products near the surface and in the mid and upper troposphere as well as in the stratosphere promise to make it possible to characterize and model phenomena that are key for short-term atmospheric processes, from weather patterns to long-term processes, such as interannual variability and climate change.

  10. Spectral Resolution and Coverage Impact on Advanced Sounder Information Content

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    Advanced satellite sensors are tasked with improving global measurements of the Earth s atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Achieving such measurement improvements requires instrument system advancements. This presentation focuses on the impact of spectral resolution and coverage changes on remote sensing system information content, with a specific emphasis on thermodynamic state and trace species variables obtainable from advanced atmospheric sounders such as the Infrared Atmospheric Sounding Interferometer (IASI) and Cross-track Infrared Sounder (CrIS) systems on the MetOp and NPP/NPOESS series of satellites. Key words: remote sensing, advanced sounders, information content, IASI, CrIS

  11. Radiometric consistency assessment of hyperspectral infrared sounders

    NASA Astrophysics Data System (ADS)

    Wang, L.; Han, Y.; Jin, X.; Chen, Y.; Tremblay, D. A.

    2015-07-01

    The radiometric and spectral consistency among the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared Sounder (CrIS) is fundamental for the creation of long-term infrared (IR) hyperspectral radiance benchmark datasets for both inter-calibration and climate-related studies. In this study, the CrIS radiance measurements on Suomi National Polar-orbiting Partnership (SNPP) satellite are directly compared with IASI on MetOp-A and -B at the finest spectral scale and with AIRS on Aqua in 25 selected spectral regions through one year of simultaneous nadir overpass (SNO) observations to evaluate radiometric consistency of these four hyperspectral IR sounders. The spectra from different sounders are paired together through strict spatial and temporal collocation. The uniform scenes are selected by examining the collocated Visible Infrared Imaging Radiometer Suite (VIIRS) pixels. Their brightness temperature (BT) differences are then calculated by converting the spectra onto common spectral grids. The results indicate that CrIS agrees well with IASI on MetOp-A and IASI on MetOp-B at the longwave IR (LWIR) and middle-wave IR (MWIR) bands with 0.1-0.2 K differences. There are no apparent scene-dependent patterns for BT differences between CrIS and IASI for individual spectral channels. CrIS and AIRS are compared at the 25 spectral regions for both Polar and Tropical SNOs. The combined global SNO datasets indicate that, the CrIS-AIRS BT differences are less than or around 0.1 K among 21 of 25 comparison spectral regions and they range from 0.15 to 0.21 K in the remaining 4 spectral regions. CrIS-AIRS BT differences in some comparison spectral regions show weak scene-dependent features.

  12. Radiometric consistency assessment of hyperspectral infrared sounders

    NASA Astrophysics Data System (ADS)

    Wang, L.; Han, Y.; Jin, X.; Chen, Y.; Tremblay, D. A.

    2015-11-01

    The radiometric and spectral consistency among the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared Sounder (CrIS) is fundamental for the creation of long-term infrared (IR) hyperspectral radiance benchmark data sets for both intercalibration and climate-related studies. In this study, the CrIS radiance measurements on Suomi National Polar-orbiting Partnership (SNPP) satellite are directly compared with IASI on MetOp-A and MetOp-B at the finest spectral scale and with AIRS on Aqua in 25 selected spectral regions through simultaneous nadir overpass (SNO) observations in 2013, to evaluate radiometric consistency of these four hyperspectral IR sounders. The spectra from different sounders are paired together through strict spatial and temporal collocation. The uniform scenes are selected by examining the collocated Visible Infrared Imaging Radiometer Suite (VIIRS) pixels. Their brightness temperature (BT) differences are then calculated by converting the spectra onto common spectral grids. The results indicate that CrIS agrees well with IASI on MetOp-A and IASI on MetOp-B at the long-wave IR (LWIR) and middle-wave IR (MWIR) bands with 0.1-0.2 K differences. There are no apparent scene-dependent patterns for BT differences between CrIS and IASI for individual spectral channels. CrIS and AIRS are compared at the 25 spectral regions for both polar and tropical SNOs. The combined global SNO data sets indicate that the CrIS-AIRS BT differences are less than or around 0.1 K among 21 of 25 spectral regions and they range from 0.15 to 0.21 K in the remaining four spectral regions. CrIS-AIRS BT differences in some comparison spectral regions show weak scene-dependent features.

  13. Cloud Clearing of Infrared Sounder Radiances.

    NASA Astrophysics Data System (ADS)

    Rizzi, R.; Serio, C.; Kelly, G.; Tramutoli, V.; McNally, A.

    1994-02-01

    R. RizziEuropean Centre for Medium-Range Weather Forecasts, Reading, England European Organization for the Exploitation of Meteorological Satellites, Darmstadt, Germany C. SerioDipartimento di Scienze Fisiche, Napoli, Italy G. KellyEuropean Centre for Medium-Range Weather Forecasts, Reading, England V. TramutoliDipartimento di Ingegneria e Fisica deil' Ambiente, Potenza, Italy A. McNallyEuropean Centre for Medium-Range Weather Forecasts, Reading, EnglandThe paper compares the performance of three different schemes for computing clear-sky brightness temperature from cloud-affected measurements. Both the ability to detect clouds and to estimate the equivalent clear-sky brightness temperature are examined. Simulated brightness temperatures computed from the ECMWF operational analysis are used as a reference, together with Advanced Very High Resolution Radiometer (AVHRR)-derived sea surface temperature and cloud content within High-Resolution Infrared Radiation Sounder (HIRS) fields of view. Cloud masks obtained from the cloud-detection schemes are compared with cloud masks obtained from AVHRR data; clear-column brightness temperatures for HIRS/2 channels 4, 7, and 13 are compared with the simulated ones; simulated clear-column brightness temperatures in the HIRS/2 window channel 8 are validated with equivalent products from AVHRR data. The comparison highlights some problems in the operational implementation of the NESDIS cloud-clearing scheme and with the operational filtering scheme of the United Kingdom Meteorological Office.

  14. Global Daily Atmospheric State Profiles from the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Chahine, Moustafa T.

    2008-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 (micro)m to 15.4 (micro)m and a 13.5 km footprint. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy on a global scale, as well as water vapor profiles, clouds, dust and trace gas amounts for CO2, CO, SO2, O3 and CH4.[1] AIRS data are used for weather forecasting and studies of global climate change. The AIRS is a 'facility' instrument developed by NASA as an experimental demonstration of advanced technology for remote sensing and the benefits of high resolution infrared spectra to science investigations.

  15. Advanced Atmospheric Sounder and Imaging Radiometer (AASIR)

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Design information for the Advanced Atmospheric Sounder and Imaging Radiometer is reported, which was developed to determine the configuration of a sensor for IR and visible imaging. The areas of technology reported include: systems design, optics, mechanics, electronics, detectors, radiative cooler, and radiometric calibration.

  16. Radiation budget studies using collocated observations from advanced Very High Resolution Radiometer, High-Resolution Infrared Sounder/2, and Earth Radiation Budget Experiment instruments

    NASA Technical Reports Server (NTRS)

    Ackerman, Steven A.; Frey, Richard A.; Smith, William L.

    1992-01-01

    Collocated observations from the Advanced Very High Resolution Radiometer (AVHRR), High-Resolution Infrared Sounder/2 (HIRS/2), and Earth Radiation Budget Experiment (ERBE) instruments onboard the NOAA 9 satellite are combined to describe the broadband and spectral radiative properties of the earth-atmosphere system. Broadband radiative properties are determined from the ERBE observations, while spectral properties are determined from the HIRS/2 and AVHRR observations. The presence of clouds, their areal coverage, and cloud top pressure are determined from a combination of the HIRS/2 and the AVHRR observations. The CO2 slicing method is applied to the HIRS/2 to determine the presence of upper level clouds and their effective emissivity. The AVHRR data collocated within the HIRS/2 field of view are utilized to determine the uniformity of the scene and retrieve sea surface temperature. Changes in the top of the atmosphere longwave and shortwave radiative energy budgets, and the spectral distribution of longwave radiation are presented as a function of cloud amount and cloud top pressure. The radiative characteristics of clear sky conditions over oceans are presented as a function of sea surface temperature and atmospheric water vapor structure.

  17. GRIPS - The Geostationary Remote Infrared Pollution Sounder

    NASA Astrophysics Data System (ADS)

    Spackman, Ryan; Dickerson, Russell; Schoeberl, Mark; Bloom, Hal; Gordley, Larry; McHugh, Martin; Thompson, Anne; Burrows, John; Zeng, Ning; Marshall, Tom; Fish, Chad; Kim, Jhoon; Park, Rokjin; Warner, Juying; Bhartia, Pawan; Kollonige, Debra

    2013-04-01

    Climate change and air quality are the most pressing environmental issues of the 21st century for America and for the world as a whole. Despite decades of research, the sources and sinks of key greenhouse gases and other pollutants remain highly uncertain making atmospheric composition predictions difficult. The Geostationary Remote Infrared Pollution Sounder (GRIPS) will measure carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4). By using measurements of nitrous oxide (N2O) and the O2 A-band to help correct for clouds and aerosols, GRIPS will achieve unprecedented precision. Together these gases account for about 85% of all climate forcing and they impact atmospheric ozone (O3). GRIPS, employing gas-filter correlation radiometry, uses the target gases themselves in place of dispersive elements to achieve outstanding throughput, sensitivity, and specificity. Because it uses a combination of reflected and thermal IR, GRIPS will detect trace gas concentrations right down to the Earth's surface. When flown in parallel to a UV/VIS sensor such as GEMS on GEO-KOMPSAT-2B over East Asia or the Sentinel 4 on MTG over Europe/Africa, the combination offers powerful finger-printing capabilities to distinguish and quantify diverse pollution sources such as electricity generation, biomass burning, and motor vehicles. From geostationary orbit, GRIPS will be able to focus on important targets to quantify sources, net flux, diurnal cycles, and long-range transport of these key components in the Earth's radiative balance and air quality.

  18. GRIPS - The Geostationary Remote Infrared Pollution Sounder

    NASA Astrophysics Data System (ADS)

    Dickerson, R. R.; Schoeberl, M. R.; Gordley, L. L.; McHugh, M. J.; Thompson, A. M.; Burrows, J. P.; Zeng, N.; Marshall, B. T.; Fish, C. S.; Spackman, J. R.; Kim, J.; Park, R.; Warner, J. X.; Bhartia, P. K.; Kollonige, D. E.

    2012-12-01

    Climate change and air quality are the most pressing environmental issues of the 21st century - for America and for the world as a whole. Despite decades of research, the sources and sinks of key greenhouse gases and other pollutants remain highly uncertain making atmospheric composition predictions difficult. The Geostationary Remote Infrared Pollution Sounder (GRIPS) will measure carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4). By using measurements of nitrous oxide (N2O) and the O2 A-band to help correct for clouds and aerosols, GRIPS will achieve unprecedented precision. Together these gases account for about 85% of all climate forcing and they impact atmospheric ozone (O3). GRIPS, employing gas-filter correlation radiometry, uses the target gases themselves in place of dispersive elements to achieve outstanding throughput, sensitivity, and specificity. Because it uses a combination of reflected and thermal IR, GRIPS will detect trace gas concentrations right down to the Earth's surface. When flown in parallel to a UV/VIS sensor such as GEMS on GEO-KOMPSAT-2B over East Asia or the Sentinel 4 on MTG over Europe/Africa, the combination offers powerful finger-printing capabilities to distinguish and quantify diverse pollution sources such as electricity generation, biomass burning, and motor vehicles. From geostationary orbit, GRIPS will be able to focus on important targets to quantify sources, net flux, diurnal cycles, and long-range transport of these key components in the Earth's radiative balance and air quality.

  19. Impact of Measurement System Characteristics on Advanced Sounder Information Content

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    Advanced satellite sensors are tasked with improving global observations of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Achieving such an improvement in geophysical information inferred from these observations requires optimal usage of data from current systems as well as instrument system enhancements for future sensors. This presentation addresses results of tradeoff studies evaluating the impact of spectral resolution, spectral coverage, instrument noise, and a priori knowledge on remote sensing system information content, with a specific emphasis on thermodynamic state and trace species information obtainable from advanced atmospheric sounders. Particular attention will be devoted toward information achievable from the Atmospheric InfraRed Sounder (AIRS) on the NASA EOS Aqua satellite in orbit since 2002, the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A since 2006, and the Cross-track Infrared Sounder (CrIS) instrument to fly aboard the NPP and JPSS series of satellites expected to begin in late 2011. While all of these systems cover nearly the same infrared spectral extent, they have very different number of channels, instrument line shapes, coverage continuity, and instrument noise. AIRS is a grating spectrometer having 2378 discrete spectral channels ranging from about 0.4 to 2.2/cm resolution; IASI is a Michelson interferometer with 8461 uniformly-spaced spectral channels of 0.5/cm (apodized) resolution; and CrIS is a Michelson interferometer having 1305 spectral channels of 0.625, 1.250, and 2.50/cm (unapodized) spectral resolution, respectively, over its three continuous but non-overlapping bands. Results of tradeoff studies showing information content sensitivity to assumed measurement system characteristics will be presented.

  20. Advanced Meteorological Temperature Sounder (AMTS) study

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The results of a system definition study (theoretical) for an Advanced Meteorological Temperature Sounder (AMTS) is described. From the data the atmospheric temperature and humidity profiles can be determined over the entire earth's surface with a spatial resolution of 45 km. x 45 km; amounts and type of cloud cover as well as surface temperatures of the earth are also determined. The major purpose of the study was to determine the feasibility of cooling twenty-eight detectors to the 80-90 Kelvin region by means of a radiative cooler. Other related considerations were achieving high signal-to-noise ratios, maximizing optical throughput through the grating spectrometer, and reducing preamplifier noise. A detailed optical design of an f/5 Ebert-Fastie spectrometer was carried out to verify that image quality is adequate; field lenses near the spectrometer focal plane were designed to image the grating onto the smallest size detectors for each channel.

  1. The Atmospheric Infrared Sounder Version 6 Cloud Products

    NASA Technical Reports Server (NTRS)

    Kahn, B. H.; Irion, F. W.; Dang, V. T.; Manning, E. M.; Nasiri, S. L.; Naud, C. M.; Blaisdell, J. M.; Schreier, M. M..; Yue, Q.; Bowman, K. W.; Fetzer, E. J.; Hulley, G. C.; Liou, K. N.; Lubin, D.; Ou, S. C.; Susskind, J.; Takano, Y.; Tian, B.; Worden, J. R.

    2014-01-01

    The version 6 cloud products of the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit (AMSU) instrument suite are described. The cloud top temperature, pressure, and height and effective cloud fraction are now reported at the AIRS field-of-view (FOV) resolution. Significant improvements in cloud height assignment over version 5 are shown with FOV-scale comparisons to cloud vertical structure observed by the CloudSat 94 GHz radar and the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP). Cloud thermodynamic phase (ice, liquid, and unknown phase), ice cloud effective diameter D(sub e), and ice cloud optical thickness (t) are derived using an optimal estimation methodology for AIRS FOVs, and global distributions for 2007 are presented. The largest values of tau are found in the storm tracks and near convection in the tropics, while D(sub e) is largest on the equatorial side of the midlatitude storm tracks in both hemispheres, and lowest in tropical thin cirrus and the winter polar atmosphere. Over the Maritime Continent the diurnal variability of tau is significantly larger than for the total cloud fraction, ice cloud frequency, and D(sub e), and is anchored to the island archipelago morphology. Important differences are described between northern and southern hemispheric midlatitude cyclones using storm center composites. The infrared-based cloud retrievals of AIRS provide unique, decadal-scale and global observations of clouds over portions of the diurnal and annual cycles, and capture variability within the mesoscale and synoptic scales at all latitudes.

  2. Regional Assimilation of NASA Atmospheric Infrared Sounder (AIRS) Data

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Lapenta, William; Jediovec, Gary J.; McCarty, William; Mecikalski, John R.

    2004-01-01

    The NASA Short-term Prediction Research and Transition (SPORT) Center seeks to accelerate the infusion of NASA Earth Science Enterprise (ESE) observations, data assimilation and modeling research into NW S forecast operations and decision-making. The Atmospheric Infrared Sounder (AIRS), is expected to advance climate research and weather prediction into the 21 st century. It is one of six instruments onboard Aqua, a satellite that is part of NASA s Earth Observing System. AIRS, along with two partner microwave sounding instruments, represents the most advanced atmospheric sounding system ever deployed in space. The system is capable of measuring the atmospheric temperature in the troposphere with radiosonde accuracies of 1 K over 1 km-thick layers under both clear and cloudy conditions, while the accuracy of the derived moisture profiles will exceed that obtained by radiosondes. It is imperative that the scientific community is prepared to take full advantage of next-generation satellite data that will become available within the next decade. The purpose of this paper is to describe a procedure designed to optimally assimilate AIRS data at high spatial resolution over both land and ocean. The assimilation system used in this study is the Local Analysis and Prediction System (LAPS) developed at the Forecast System Laboratory used extensively around the globe. Results will focus on quality control issues associated with AIRS, optimal assimilation strategies, and the impact of the AIRS data on subsequent numerical forecasts at 12 km produced by the next generation Weather Research and Forecast (WRF) model.

  3. On Cirrus Cloud Fields Measured by the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Kahn, Brian H.; Eldering, Annmarie; Liou, Kuo Nan

    2006-01-01

    A viewgraph presentation showing trends in clouds measured by the Atmospheric Infrared Sounder (AIRS) is given. The topics include: 1) Trends in clouds measured by AIRS: Are they reasonable? 2) Single and multilayered cloud trends; 3) Retrievals of thin cirrus D(sub e) and tau: Single-layered cloud only; 4) Relationships between ECF, D(sub e), tau, and T(sub CLD); and 5) MODIS vs. AIRS retrievals.

  4. Application of Atmospheric Infrared Sounder (AIRS) Data to Climate Research

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Gregorich, David; Gaiser, Steve; Chahine, Moustafa T.

    2004-01-01

    The application of hyper spectral radiometric data to climate research requires very high absolute radiometric accuracy and stability. We use cloud-free tropical ocean data from the Atmospheric InfraRed Sounder (AIR) Calibration Data Subset (ADCS) to show that the radiometric precision and stability required climate applications has been achieved. The sea surface skin temperatures derived from the AIRS 2616cm-1 super window channel are stable relative to the RTG.SST at the better than 8 mK/year level, and the spectral calibration is stable at the 1 ppm/year level. The excellent stability and accuracy are the result of the implementation of AIRS as a grating array spectrometer, which is cooled and stabilized within 10 mK at 155 K. Analysis of daily measurements of the temperature gradient between the surface and 7 km altitude show that the AIRS Calibration Data Subset has applications which extend its original intent for calibration support to climate research. The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua satellite was launched into polar orbit in May 2002. AIRS covers the spectral region from 640 to 2700 cm-1 with 2378 independent channels and represents the first of a new generation of hyper spectral resolution sounders in support of global sounding data for weather forecasting and climate research.

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

    NASA Astrophysics Data System (ADS)

    Ishimoto, H.; Masuda, K.

    2014-12-01

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

  6. Requirements for a Moderate-Resolution Infrared Imaging Sounder (MIRIS)

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Gerber, Andrew J.; Kuai, Le; Gontijo, I.; DeLeon, Berta; Susskind, Joel; Iredell, Lena; Bajpai, Shyam

    2013-01-01

    The high cost of imaging and sounding from space warrants exploration of new methods for obtaining the required information, including changing the spectral band sets, employing new technologies and merging instruments. In some cases we must consider relaxation of the current capability. In others, we expect higher performance. In general our goal is to meet the VIIRS and CrIS requirements while providing the enhanced next generation capabilities: 1) Hyperspectral Imaging in the Vis/NIR bands, 2) High Spatial Resolution Sounding in the Infrared bands. The former will improve the accuracy of ocean color products, aerosols and water vapor, surface vegetation and geology. The latter will enable the high-impact achieved by the current suite of hyperspectral infrared sounders to be achieved by the next generation high resolution forecast models. We examine the spectral, spatial and radiometric requirements for a next generation system and technologies that can be applied from the available inventory within government and industry. A two-band grating spectrometer instrument called the Moderate-resolution Infrared Imaging Sounder (MIRIS) is conceived that, when used with the planned NASA PACE Ocean Color Instrument (OCI) will meet the vast majority of CrIS and VIIRS requirements in the all bands and provide the next generation capabilities desired. MIRIS resource requirements are modest and the Technology Readiness Level is high leading to the expectation that the cost and risk of MIRIS will be reasonable.

  7. Channel alignment and radiometry in hyperspectral atmospheric infrared sounders

    NASA Technical Reports Server (NTRS)

    Elliott, Denis A.; Aumanna, H. H.; Pagano, Thomas S.; Overoye, Kenneth R.; Schindler, Rudolf A.

    2005-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyper-spectral infrared sounder which covers the 3.7 to 15,4 micron region with 2378 spectral channels. The AIRS instrument specification called for spatial co-registration of all channels to better than 2% of the field of view. Pre-launch testing confirmed that this requirement was met, since the standard deviations in the centroids was about 1% of the 13.5 km IFOV in scan and 3% in track. Detailed analysis of global AIRS data show that the typical scene gradient in 10 micron window channels is about I .3K/km rms. The way these gradients, which are predominantly caused by clouds, manifest themselves in the data depends on the details of the instrument design and the way the spectral channels are used in the data analysis, AIRS temperature and moisture retrievals use 328 of the 2378 channels from 17 independent arrays. As a result, the effect of the boresight misalignment averages to zero mean. Any increase in the effective noise is less than 0.2K. Also, there is no discernable performance degradation of products at the 45 km spatial resolution in the presence of partially cloudy scenes with up to 80% cloudiness. Single pixel radiometric differences between channels with boresight alignment differences can be appreciable and can affect scientific investigations on a single 15km footprint scale, particularly near coastlines, thunderstorms and surface emissivity inhomogeneities.

  8. Determination of cloud parameters from infrared sounder data

    NASA Technical Reports Server (NTRS)

    Yeh, H.-Y. M.

    1984-01-01

    The World Climate Research Programme (WCRP) plan is concerned with the need to develop a uniform global cloud climatology as part of a broad research program on climate processes. The International Satellite Cloud Climatology Project (ISCCP) has been approved as the first project of the WCRP. The ISCCP has the basic objective to collect and analyze satellite radiance data to infer the global distribution of cloud radiative properties in order to improve the modeling of cloud effects on climate. Research is conducted to explore an algorithm for retrieving cloud properties by utilizing the available infrared sounder data from polar-orbiting satellites. A numerical method is developed for computing cloud top heights, amount, and emissivity on the basis of a parameterized infrared radiative transfer equation for cloudy atmospheres. Theoretical studies were carried out by considering a synthetic atmosphere.

  9. Science Highlights and Lessons Learned from the Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Fetzer, Eric J.; Suda, Jarrod; Licata, Steve

    2011-01-01

    The Atmospheric Infrared Sounder (AIRS) and companion instrument, the Advanced Microwave Sounding Unit (AMSU) on the NASA Earth Observing System Aqua spacecraft are facility instruments designed to support measurements of atmospheric temperature, water vapor and a wide range of atmospheric constituents in support of weather forecasting and scientific research in climate and atmospheric chemistry. This paper is an update to the science highlights from a paper by the authors released last year and also looks back at the lessons learned and future needs of the scientific community. These lessons not only include requirements on the measurements, but scientific shortfalls as well. Results from the NASA Science Community Workshop in IR and MW Sounders relating to AIRS and AMSU requirements and concerns are covered and reflect much of what has been learned and what is needed for future atmospheric sounding from Low Earth Orbit.

  10. The TIROS-N high resolution infrared radiation sounder

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1979-01-01

    The high-resolution infrared radiation sounder (HIRS/2) was developed and flown on the Television and Infrared Observation Satellite, N Series (TIROS-N) as one means of obtaining atmospheric vertical profile information. The HIRS/2 receives visible and infrared spectrum radiation through a single telescope and selects 20 narrow spectral channels by means of a rotating filter wheel. A passive radiant cooler provides an operating temperature of 106.7K for the HgCdTe and InSb detectors while the visible detector operates at instrument frame temperature. Low noise amplifiers and digital processing provide 13 bit data for spacecraft data multiplexing and transmission. The qualities of system performance that determine sounding capability are the dynamic range of data collection, the noise equivalent radiance of the system, the registration of the air columns sampled in each channel, and the ability to upgrade the calibration of the instrument to maintain the performance standard throughout life. The basic performance of the instrument in test is described. Early orbital information from the TIROS-N launched on October 13, 1978 are given and some observations on system quality are made.

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

    SciTech Connect

    Flynn, Connor J.

    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.

  12. Sensitivity Analysis for Atmospheric Infrared Sounder (AIRS) CO2 Retrieval

    NASA Technical Reports Server (NTRS)

    Gat, Ilana

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS) is a thermal infrared sensor able to retrieve the daily atmospheric state globally for clear as well as partially cloudy field-of-views. The AIRS spectrometer has 2378 channels sensing from 15.4 micrometers to 3.7 micrometers, of which a small subset in the 15 micrometers region has been selected, to date, for CO2 retrieval. To improve upon the current retrieval method, we extended the retrieval calculations to include a prior estimate component and developed a channel ranking system to optimize the channels and number of channels used. The channel ranking system uses a mathematical formalism to rapidly process and assess the retrieval potential of large numbers of channels. Implementing this system, we identifed a larger optimized subset of AIRS channels that can decrease retrieval errors and minimize the overall sensitivity to other iridescent contributors, such as water vapor, ozone, and atmospheric temperature. This methodology selects channels globally by accounting for the latitudinal, longitudinal, and seasonal dependencies of the subset. The new methodology increases accuracy in AIRS CO2 as well as other retrievals and enables the extension of retrieved CO2 vertical profiles to altitudes ranging from the lower troposphere to upper stratosphere. The extended retrieval method for CO2 vertical profile estimation using a maximum-likelihood estimation method. We use model data to demonstrate the beneficial impact of the extended retrieval method using the new channel ranking system on CO2 retrieval.

  13. Validation of the Radiometric Stability of the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Aumann, H. H.; Elliott, D.; Strow, L. L.

    2012-01-01

    It has been widely accepted that an infrared sounder in low polar orbit is capable of producing climate quality data, if the spectral brightness temperatures have instrumental trends of less than 10 mK/yr. Achieving measurement stability at this level is not only very demanding of the design of the instrument, it is also pushes the state of art of measuring on orbit what stability is actually achieved. We discuss this using Atmospheric Infrared Sounder (AIRS) L1B data collected between 2002 and 2011. We compare the L1B brightness temperature observed in cloud filtered night tropical ocean spectra (obs) to the brightness temperature calculated based on the known surface emissivity, temperature and water vapor profiles from the ECMWF ReAnalysis (ERA) and the growth rates of CO2, N2O and Ozone. The trend in (obs-calc) is a powerful tool for the evaluation of the stability of the 2378 AIRS channels. We divided the channels into seven classes: All channels which sound in the stratosphere (at pressure levels below 150 hPa), 14 micron CO2 sounding, 4 micron CO2 P-branch sounding, 4 micron CO2 R-branch sounding, water vapor sounding, shortwave surface sounding and longwave surface sounding. The peak in the weighting function at 1050 hPa separates sounding and surface channels. The boundary between shortwave and longwave is 5 microns. Except for the stratosphere sounding channels, the remaining six groups have (obs-calc) trends of less than 20 mK/yr. The longwave surface channels have trends of 2 mK/yr, significantly less than the 8 mK/yr trend seem in the shortwave window channels. Based on the design of the instrument, trends within a group of channels should be the same. While the longwave and shortwave trends are less than the canonical 10 mK/yr, the larger trend in the shortwave channels could be an artifact of using the pre-launch determined calibration coefficients. This is currently under evaluation. The trend in (obs-calc) for the non-surface sounding channels, in

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

    NASA Astrophysics Data System (ADS)

    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.

  15. How Well Can Infrared Sounders Observe the Atmosphere and Surface Through Clouds?

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Smith, William L.; Strow, L. Larrabee; Yang, Ping

    2010-01-01

    Infrared sounders, such as the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared sounder (CrIS), have a cloud-impenetrable disadvantage in observing the atmosphere and surface under opaque cloudy conditions. However, recent studies indicate that hyperspectral, infrared sounders have the ability to detect cloud effective-optical and microphysical properties and to penetrate optically thin clouds in observing the atmosphere and surface to a certain degree. We have developed a retrieval scheme dealing with atmospheric conditions with cloud presence. This scheme can be used to analyze the retrieval accuracy of atmospheric and surface parameters under clear and cloudy conditions. In this paper, we present the surface emissivity results derived from IASI global measurements under both clear and cloudy conditions. The accuracy of surface emissivity derived under cloudy conditions is statistically estimated in comparison with those derived under clear sky conditions. The retrieval error caused by the clouds is shown as a function of cloud optical depth, which helps us to understand how well infrared sounders can observe the atmosphere and surface through clouds.

  16. Daily global maps of carbon monoxide from NASA's Atmospheric Infrared Sounder

    NASA Astrophysics Data System (ADS)

    McMillan, W. W.; Barnet, C.; Strow, L.; Chahine, M. T.; McCourt, M. L.; Warner, J. X.; Novelli, P. C.; Korontzi, S.; Maddy, E. S.; Datta, S.

    2005-06-01

    We present the first observations of tropospheric carbon monoxide (CO) by the Atmospheric Infrared Sounder (AIRS) onboard NASA's Aqua satellite. AIRS daily coverage of ~70% of the planet represents a significant evolutionary advance in satellite trace gas remote sensing. Tropospheric CO abundances are retrieved from AIRS 4.55 μm spectral region using the full AIRS retrieval algorithm run in a research mode. The presented AIRS daily global CO maps from 22-29 September 2002 show large-scale, long-range transport of CO from anthropogenic and natural sources, most notably from biomass burning. The sequence of daily maps reveal CO advection from Brazil to the South Atlantic in qualitative agreement with previous observations. Forward trajectory analysis confirms this scenario and indicates much longer range transport into the southern Indian Ocean. Preliminary comparisons to in situ aircraft profiles indicate AIRS CO retrievals are approaching the 15% accuracy target set by pre-launch simulations.

  17. Carbon Monoxide Distribution over Peninsular Malaysia from the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    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.

  18. The Advanced Technology Microwave Sounder (ATMS): A New Operational Sensor Series

    NASA Technical Reports Server (NTRS)

    Kim, Edward; Lyu, Cheng-H Joseph; Leslie, R. Vince; Baker, Neal; Mo, Tsan; Sun, Ninghai; Bi, Li; Anderson, Mike; Landrum, Mike; DeAmici, Giovanni; Gu, Degui; Foo, Alex; Ibrahim, Wael; Robinson, Kris; Chidester, Lynn; Shiue, James

    2012-01-01

    ATMS is a new satellite microwave sounding sensor designed to provide operational weather agencies with atmospheric temperature and moisture profile information for global weather forecasting and climate applications. ATMS will continue the microwave sounding capabilities first provided by its predecessors, the Microwave Sounding Unit (MSU) and Advanced Microwave Sounding Unit (AMSU). The first ATMS was launched October 28, 2011 on board the Suomi National Polar-orbiting Partnership (S-NPP) satellite. Microwave soundings by themselves are the highest-impact input data used by Numerical Weather Prediction (NWP) models; and ATMS, when combined with the Cross-track Infrared Sounder (CrIS), forms the Cross-track Infrared and Microwave Sounding Suite (CrIMSS). The microwave soundings help meet NWP sounding requirements under cloudy sky conditions and provide key profile information near the surface

  19. Lossless data compression for infrared hyperspectral sounders: an update

    NASA Astrophysics Data System (ADS)

    Huang, Bormin; Huang, Hung-Lung A.; Ahuja, Alok; Schmit, Timothy J.; Heymann, Roger W.

    2004-10-01

    The compression of hyperspectral sounder data is beneficial for more efficient archive and transfer given its large 3-D volume. Moreover, since physical retrieval of geophysical parameters from hyperspectral sounder data is a mathematically ill-posed problem that is sensitive to the error of the data, lossless or near-lossless compression is desired. This paper provides an update into applications of state-of-the-art 2D and 3D lossless compression algorithms such as 3D EZW, 3D SPIHT, 2D JPEG2000, 2D JPEG-LS and 2D CALIC for hyperspectral sounder data. In addition, in order to better explore the correlations between the remote spectral regions affected by the same type of atmospheric absorbing constituents or clouds, the Bias-Adjusted Reordering (BAR) scheme is presented which reorders the data such that the bias-adjusted distance between any two neighboring vectors is minimized. This scheme coupled with any of the state-of-the-art compression algorithms produces significant compression gains.

  20. The Advanced Technology Microwave Sounder (ATMS): First Year On-Orbit

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.

    2012-01-01

    The Advanced Technology Microwave Sounder (ATMS) is a new satellite microwave sounding sensor designed to provide operational weather agencies with atmospheric temperature and moisture profile information for global weather forecasting and climate applications. A TMS will continue the microwave sounding capabilities first provided by its predecessors, the Microwave Sounding Unit (MSU) and Advanced Microwave Sounding Unit (AMSU). The first flight unit was launched a year ago in October, 2011 aboard the Suomi-National Polar-Orbiting Partnership (S-NPP) satellite, part of the new Joint Polar-Orbiting Satellite System (JPSS). Microwave soundings by themselves are the highest-impact input data used by Numerical Weather Prediction models; and A TMS, when combined with the Cross-track Infrared Sounder (CrIS), forms the Cross-track Infrared and Microwave Sounding Suite (CrIMSS). The microwave soundings help meet sounding requirements under cloudy sky conditions and provide key profile information near the surface. ATMS was designed & built by Aerojet Corporation in Azusa, California, (now Northrop Grumman Electronic Systems). It has 22 channels spanning 23-183 GHz, closely following the channel set of the MSU, AMSU-AI/2, AMSU-B, Microwave Humidity Sounder (MHS), and Humidity Sounder for Brazil (HSB). It continues their cross-track scanning geometry, but for the first time, provides Nyquist sample spacing. All this is accomplished with approximately V. the volume, Y, the mass, and Y, the power of the three AMSUs. A description will be given of its performance from its first year of operation as determined by post-launch calibration activities. These activities include radiometric calibration using the on-board warm targets and cold space views, and geolocation determination. Example imagery and zooms of specific weather events will be shown. The second ATMS flight model is currently under construction and planned for launch on the "Jl" satellite of the JPSS program in

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

    NASA Technical Reports Server (NTRS)

    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.

  2. Improving Regional Forecast by Assimilating Atmospheric InfraRed Sounder (AIRS) Profiles into WRF Model

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Brad; Jedlovec, Gary J.

    2009-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses and produce improved forecasts. One such source comes from the Atmospheric InfraRed Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. The purpose of this paper is to describe a procedure to optimally assimilate high resolution AIRS profile data into a regional configuration of the Advanced Research WRF (ARW) version 2.2 using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background type, and an optimal methodology for ingesting AIRS temperature and moisture profiles as separate overland and overwater retrievals with different error characteristics. The AIRS thermodynamic profiles are derived from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm and contain information about the quality of each temperature layer. The quality indicators were used to select the highest quality temperature and moisture data for each profile location and pressure level. The analyses were then used to conduct a month-long series of regional forecasts over the continental U.S. The long-term impacts of AIRS profiles on forecast were assessed against verifying NAM analyses and stage IV precipitation data.

  3. Suomi NPP/JPSS Cross-track Infrared Sounder (CrIS): Calibration Validation With The Aircraft Based Scanning High-resolution Interferometer Sounder (S-HIS)

    NASA Astrophysics Data System (ADS)

    Taylor, J. K.; Revercomb, H. E.; Tobin, D.; Knuteson, R. O.; Best, F. A.; Adler, D. A.; Pettersen, C.; Garcia, R. K.; Gero, P.

    2013-12-01

    To better accommodate climate change monitoring and improved weather forecasting, there is an established need for higher accuracy and more refined error characterization of radiance measurements from space and the corresponding geophysical products. This need has led to emphasizing direct tests of on-orbit performance, referred to as validation. Currently, validation typically involves (1) collecting high quality reference data from airborne and/or ground-based instruments during the satellite overpass, and (2) a detailed comparison between the satellite-based radiance measurements and the corresponding high quality reference data. Additionally, for future missions technology advancements at the University of Wisconsin Space Science and Engineering Center (UW-SSEC) have led to the development of an on-orbit absolute radiance reference utilizing miniature phase change cells to provide direct on-orbit traceability to International Standards (SI). The detailed comparison between the satellite-based radiance measurements and the corresponding measurements made from a high-altitude aircraft must account for instrument noise and scene variations, as well as differences in instrument observation altitudes, view angles, spatial footprints, and spectral response. Most importantly, for the calibration validation process to be both accurate and repeatable the reference data instrument must be extremely well characterized and understood, carefully maintained, and accurately calibrated, with traceability to absolute standards. The Scanning High-resolution Interferometer Sounder (S-HIS) meets and exceeds these requirements and has proven to do so on multiple airborne platforms, each with significantly different instrument operating environments. The Cross-track Infrared Sounder (CrIS) on Suomi NPP, launched 28 October 2011, is designed to give scientists more refined information about Earth's atmosphere and improve weather forecasts and our understanding of climate. CrIS is an

  4. The Geostationary Remote Infrared Pollution Sounder (GRIPS): measurement of the carbon gases from space

    NASA Astrophysics Data System (ADS)

    Schoeberl, M.; Dickerson, R.; Marshall, B. T.; McHugh, M.; Fish, C.; Bloom, H.

    2013-09-01

    Climate change and air quality are the most pressing environmental issues of the 21st century. Despite decades of research, the sources and sinks of key greenhouse gases remain highly uncertain [IPCC1] making quantitative predictions of atmospheric composition and their impacts. The Geostationary Remote Infrared Pollution Sounder (GRIPS) is a multi-purpose instrument designed to reduce uncertainty associated with atmospheric radiative forcing. GRIPS will measure will measure greenhouse gases and aerosols - two of the most important elements in the earth's radiation budget. GRIPS will observe carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), - the carbon gases, nitrous oxide (N2O), water vapor and aerosols with unprecedented precision through the atmosphere. The GRIPS instrument uses gas filter correlation radiometry (GFCR) to detect reflected and thermal IR radiation to detect the gases and the reflected solar radiation in the visible and short-wave infrared bands for aerosols. GRIPS is designed to have sensitivity down to the Earth's surface at ~2-8km nadir resolution. GRIPS can resolve CO2, CO, and CH4 anomalies in the planetary boundary layer and the free troposphere to quantify lofting, diurnal variations and longrange transport. With repeated measurements throughout the day GRIPS can maximize the number of cloud free measurements determining biogenic and anthropogenic sources, sinks, and fluxes. GRIPS is highly complementary to the Orbiting Carbon Observatory, OCO-2, the geostationary Tropospheric Emissions: Monitoring of Pollution (TEMPO) and Advanced Baseline Imager (ABI) and other existing and planned missions.

  5. Atmospheric, Cloud, and Surface Parameters Retrieved from Satellite Ultra-spectral Infrared Sounder Measurements

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Liu, Xu; Larar, Allen M.; Smith, William L.; Yang, Ping; Schluessel, Peter; Strow, Larrabee

    2007-01-01

    An advanced retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. This physical inversion scheme has been developed, dealing with cloudy as well as cloud-free radiance observed with ultraspectral infrared sounders, to simultaneously retrieve surface, atmospheric thermodynamic, and cloud microphysical parameters. A fast radiative transfer model, which applies to the clouded atmosphere, is used for atmospheric profile and cloud parameter retrieval. A one-dimensional (1-d) variational multivariable inversion solution is used to improve an iterative background state defined by an eigenvector-regression-retrieval. The solution is iterated in order to account for non-linearity in the 1-d variational solution. This retrieval algorithm is applied to the MetOp satellite Infrared Atmospheric Sounding Interferometer (IASI) launched on October 19, 2006. IASI possesses an ultra-spectral resolution of 0.25 cm(exp -1) and a spectral coverage from 645 to 2760 cm(exp -1). Preliminary retrievals of atmospheric soundings, surface properties, and cloud optical/microphysical properties with the IASI measurements are obtained and presented.

  6. Value-added Impact from Future Geostationary Hyperspectral Infrared Sounder Observations on Hurricane Forecasts

    NASA Astrophysics Data System (ADS)

    Li, J.; Schmit, T. J.; Li, Z.; Zhu, F.; Lim, A.; Atlas, R. M.; John, P.

    2015-12-01

    Future geostationary (Geo) advanced InfraRed (IR) sounders have finer spatial, spectral, and temporal resolutions compared with the existing GOES sounders, providing much improved resolving power of atmospheric thermodynamic information. When quantitatively assessing the value-added impact from such instruments over the current sounding systems onboard the Low Earth Orbit (Leo) satellites, the real question is what is the optimal impact using the current assimilation/forecast systems. More specifically, will assimilation of more observations from Geo IR sounders with the current assimilation/forecast systems yield improved forecast as expected? And if so, how to assimilate the high temporal resolution Geo sounding information and what is the impact on forecasts? Taken tropical cyclone (TC) forecasting as an example, this study tries to address these questions through a quick regional Observing System Simulation Experiments (r-OSSE) study. The synthetic observations are simulated from the sample ECMWF T1279 nature run (NR) for Hurricane Sandy (2012), including RAOB, the Leo AIRS, and Geo AIRS. Various experiments were carried out using WRF 3.6.1 and GSI 3.3 to study the impact on Sandy track forecast. And the study shows that a) it is critical to assign an appropriate observational error (observation error covariance matrix - O matrix) in order to show improved positive impacts from Geo AIRS over Leo AIRS; b) cycling of 3/6-hourly shows improved positive impacts over none cycling, but hourly cycling does not show further improvement on forecasts among all experiments, and c) with thinning (120 ~ 240 km), the impacts have the following order: hourly > 3-hourly > 6-hourly > none cycling. These experiments indicate that while more observations may improve forecasts, much more observations are difficult to show further improvement with the current assimilation/forecast system configurations. There exists a tradeoff between the number of observations to be assimilated

  7. Advanced sounder validation studies from recent NAST-I airborne field campaigns

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    The evolution of satellite measurement systems continues to improve their research and operational impact and is essential for advancing global observations of the Earth's atmosphere, clouds, and surface. Measurement system and data product validation is required to fully exploit these data for enabling their intended enhancements in weather prediction, climate monitoring capability, and environmental change detection. Airborne field campaigns can play a vital role in such validation and contribute to assessing and improving satellite sensor measurements and associated data products. The NASA LaRC National Airborne Sounder Testbed - Interferometer (NAST-I) was part of the aircraft payload for the two field experiments conducted to address Suomi NPP (SNPP) validation since the satellite's launch in late 2011: 1) mid-latitude flights based out of Palmdale, CA during May 2013 (SNPP-1), and 2) flights over Greenland during March 2015 while based out of Keflavik, Iceland (SNPP-2). This presentation focuses on radiance analysis from the SNPP airborne field campaigns with a particular emphasis on NAST-I inter-comparisons with the Cross-track Infrared Sounder (CrIS) for challenging cold scene conditions as observed during SNPP-2.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Data Assimilation and Regional Forecasts Using Atmospheric InfraRed Sounder (AIRS) Profiles

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Bradley; Jedlovec, Gary

    2009-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses, which in turn should lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles with an accuracy comparable to that of radiosondes. The purpose of this paper is to describe a procedure to optimally assimilate AIRS thermodynamic profiles--obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm-into a regional configuration of the Weather Research and Forecasting (WRF) model using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background field type, a methodology for ingesting AIRS profiles as separate over-land and over-water retrievals with different error characteristics, and utilization of level-by-level quality indicators to select only the highest quality data. The assessment of the impact of the AIRS profiles on WRF-Var analyses will focus on intelligent use of the quality indicators, optimized tuning of the WRF-Var, and comparison of analysis soundings to radiosondes. The analyses will be used to conduct a month-long series of regional forecasts over the continental U.S. The long-tern1 impact of AIRS profiles on forecast will be assessed against verifying radiosonde and stage IV precipitation data.

  10. Data Assimilation and Regional Forecasts using Atmospheric InfraRed Sounder (AIRS) Profiles

    NASA Technical Reports Server (NTRS)

    Zabodsky, Brad; Chou, Shih-Hung; Jedlovec, Gary J.

    2009-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses, which in turn should lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which, together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles with an accuracy comparable to that of radionsondes. The purpose of this poster is to describe a procedure to optimally assimilate AIRS thermodynamic profiles, obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm, into a regional configuration of the Weather Research and Forecasting (WRF) model using WRF-Var. The poster focuses on development of background error covariances for the regional domain and background field type, a methodology for ingesting AIRS profiles as separate over-land and over-water retrievals with different error characteristics, and utilization of level-by-level quality indicators to select only the highest quality data. The assessment of the impact of the AIRS profiles on WRF-Var analyses will focus on intelligent use of the quality indicators, optimized tuning of the WRF-Var, and comparison of analysis soundings to radiosondes. The analyses are used to conduct a month-long series of regional forecasts over the continental U.S. The long-term impact of AIRS profiles on forecast will be assessed against NAM analyses and stage IV precipitation data.

  11. Tropical Storm Beryl as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Figure 1: AIRS Microwave Image

    This is an infrared image of Tropical Storm Beryl in the western Atlantic, from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite on July 20, 2006, 1:30 am local time. This AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the hurricane. The infrared signal does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the Earth, revealing warmer temperatures (red). This infrared image shows three large regions of strong convection surrounding the core of the storm. The largest, on the northern edge of the core, also appears in the companion microwave image to contain intense precipitation.

    The image in figure 1 is created from microwave radiation emitted by Earth's atmosphere and received by the instrument. It shows where the heaviest rainfall is taking place (in blue) in the storm. Blue areas outside of the tropical storm, where there are either some clouds or no clouds indicate where the sea surface shines through.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a

  12. Demonstrating the Operational Value of Atmospheric Infrared Sounder (AIRS) Profiles in the Pre-Convective Environment

    NASA Technical Reports Server (NTRS)

    Kozlowski, Danielle; Zavodsky, Bradley; Stano, Geoffrey; Jedlovec, Gary

    2011-01-01

    The Short-term Prediction Research and Transition (SPoRT) is a project to transition those NASA observations and research capabilities to the weather forecasting community to improve the short-term regional forecasts. This poster reviews the work to demonstrate the value to these forecasts of profiles from the Atmospheric Infrared Sounder (AIRS) instrument on board the Aqua satellite with particular assistance in predicting thunderstorm forecasts by the profiles of the pre-convective environment.

  13. On the remote sensing of cloud properties from satellite infrared sounder data

    NASA Technical Reports Server (NTRS)

    Yeh, H. Y. M.

    1984-01-01

    A method for remote sensing of cloud parameters by using infrared sounder data has been developed on the basis of the parameterized infrared transfer equation applicable to cloudy atmospheres. The method is utilized for the retrieval of the cloud height, amount, and emissivity in 11 micro m region. Numerical analyses and retrieval experiments have been carried out by utilizing the synthetic sounder data for the theoretical study. The sensitivity of the numerical procedures to the measurement and instrument errors are also examined. The retrieved results are physically discussed and numerically compared with the model atmospheres. Comparisons reveal that the recovered cloud parameters agree reasonably well with the pre-assumed values. However, for cases when relatively thin clouds and/or small cloud fractional cover within a field of view are present, the recovered cloud parameters show considerable fluctuations. Experiments on the proposed algorithm are carried out utilizing High Resolution Infrared Sounder (HIRS/2) data of NOAA 6 and TIROS-N. Results of experiments show reasonably good comparisons with the surface reports and GOES satellite images.

  14. Theoretical computation of trace gases retrieval random error from measurements of high spectral resolution infrared sounder

    NASA Technical Reports Server (NTRS)

    Huang, Hung-Lung; Smith, William L.; Woolf, Harold M.; Theriault, J. M.

    1991-01-01

    The purpose of this paper is to demonstrate the trace gas profiling capabilities of future passive high spectral resolution (1 cm(exp -1) or better) infrared (600 to 2700 cm(exp -1)) satellite tropospheric sounders. These sounders, such as the grating spectrometer, Atmospheric InfRared Sounders (AIRS) (Chahine et al., 1990) and the interferometer, GOES High Resolution Interferometer Sounder (GHIS), (Smith et al., 1991) can provide these unique infrared spectra which enable us to conduct this analysis. In this calculation only the total random retrieval error component is presented. The systematic error components contributed by the forward and inverse model error are not considered (subject of further studies). The total random errors, which are composed of null space error (vertical resolution component error) and measurement error (instrument noise component error), are computed by assuming one wavenumber spectral resolution with wavenumber span from 1100 cm(exp -1) to 2300 cm(exp -1) (the band 600 cm(exp -1) to 1100 cm(exp -1) is not used since there is no major absorption of our three gases here) and measurement noise of 0.25 degree at reference temperature of 260 degree K. Temperature, water vapor, ozone and mixing ratio profiles of nitrous oxide, carbon monoxide and methane are taken from 1976 US Standard Atmosphere conditions (a FASCODE model). Covariance matrices of the gases are 'subjectively' generated by assuming 50 percent standard deviation of gaussian perturbation with respect to their US Standard model profiles. Minimum information and maximum likelihood retrieval solutions are used.

  15. Development of Level 3 (gridded) products for the Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    Granger, Stephanie L.; Leroy, Stephen S.; Manning, Evan M.; Fetzer, Eric J.; Oliphant, Robert B.; Braverman, Amy; Lee, Sung-Yung; Lambrigtsen, Bjom H.

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) sounding system is a suite of infrared and microwave instruments flown as part of NASA's Earth Observing System (EOS) onboard the Aqua platform. The AIRS dataset provides a daily, global view of Earth processes at a finer vertical resolution than ever before. However, analysis of the AIRS data is a daunting task given the sheer volume and complexity of the data. The volume of data produced by the EOS project is unprecedented; the AIRS project alone will produce many terabytes of data over the lifetime of the mission. This paper describes development of AIRS Level 3 data products that will help to alleviate problems of access and usability.

  16. The Impact of Atmospheric InfraRed Sounder (AIRS) Profiles on Short-term Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Brad; Jedlovec, Gary J.; Lapenta, William

    2007-01-01

    The Atmospheric Infrared Sounder (AIRS), together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced spacebased atmospheric sounding systems. The combined AlRS/AMSU system provides radiance measurements used to retrieve temperature profiles with an accuracy of 1 K over 1 km layers under both clear and partly cloudy conditions, while the accuracy of the derived humidity profiles is 15% in 2 km layers. Critical to the successful use of AIRS profiles for weather and climate studies is the use of profile quality indicators and error estimates provided with each profile Aside form monitoring changes in Earth's climate, one of the objectives of AIRS is to provide sounding information of sufficient accuracy such that the assimilation of the new observations, especially in data sparse region, will lead to an improvement in weather forecasts. The purpose of this paper is to describe a procedure to optimally assimilate highresolution AIRS profile data in a regional analysis/forecast model. The paper will focus on the impact of AIRS profiles on a rapidly developing east coast storm and will also discuss preliminary results for a 30-day forecast period, simulating a quasi-operation environment. Temperature and moisture profiles were obtained from the prototype version 5.0 EOS science team retrieval algorithm which includes explicit error information for each profile. The error profile information was used to select the highest quality temperature and moisture data for every profile location and pressure level for assimilation into the ARPS Data Analysis System (ADAS). The AIRS-enhanced analyses were used as initial fields for the Weather Research and Forecast (WRF) system used by the SPORT project for regional weather forecast studies. The ADASWRF system will be run on CONUS domain with an emphasis on the east coast. The preliminary assessment of the impact of the AIRS profiles will focus on quality control issues associated with AIRS

  17. Impact of Atmospheric Infrared Sounder (AIRS) Thermodynamic Profiles on Regional Weather Forecasting

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Bradley T.; Jedlovee, Gary J.

    2010-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses and lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles with accuracy comparable to that of radiosondes. The purpose of this paper is to describe a procedure to assimilate AIRS thermodynamic profile data into a regional configuration of the Advanced Research Weather Research and Forecasting (WRF-ARW) model using its three-dimension variational (3DVAR) analysis component (WRF-Var). Quality indicators are used to select only the highest quality temperature and moisture profiles for assimilation in both clear and partly cloudy regions. Separate error characteristics for land and water profiles are also used in the assimilation process. Assimilation results indicate that AIRS profiles produce an analysis closer to in situ observations than the background field. Forecasts from a 37-day case study period in the winter of 2007 show that AIRS profile data can lead to improvements in 6-h cumulative precipitation forecasts due to instability added in the forecast soundings by the AIRS profiles. Additionally, in a convective heavy rainfall event from February 2007, assimilation of AIRS profiles produces a more unstable boundary layer resulting in enhanced updrafts in the model. These updrafts produce a squall line and precipitation totals that more closely reflect ground-based observations than a no AIRS control forecast. The location of available high-quality AIRS profiles ahead of approaching storm systems is found to be of paramount importance to the amount of impact the observations will have on the resulting forecasts.

  18. Impact of Atmospheric Infrared Sounder (AIRS) Thermodynamic Profiles on Regional Precipitation Forecasting

    NASA Technical Reports Server (NTRS)

    Chou, S.-H.; Zavodsky, B. T.; Jedloved, G. J.

    2010-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses and lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles in clear and cloudy regions with accuracy which approaches that of radiosondes. The purpose of this paper is to describe an approach to assimilate AIRS thermodynamic profile data into a regional configuration of the Advanced Research WRF (ARW) model using WRF-Var. Quality indicators are used to select only the highest quality temperature and moisture profiles for assimilation in clear and partly cloudy regions, and uncontaminated portions of retrievals above clouds in overcast regions. Separate error characteristics for land and water profiles are also used in the assimilation process. Assimilation results indicate that AIRS profiles produce an analysis closer to in situ observations than the background field. Forecasts from a 37-day case study period in the winter of 2007 show that AIRS profile data can lead to improvements in 6-h cumulative precipitation forecasts resulting from improved thermodynamic fields. Additionally, in a convective heavy rainfall event from February 2007, assimilation of AIRS profiles produces a more unstable boundary layer resulting in enhanced updrafts in the model. These updrafts produce a squall line and precipitation totals that more closely reflect ground-based observations than a no AIRS control forecast. The location of available high-quality AIRS profiles ahead of approaching storm systems is found to be of paramount importance to the amount of impact the observations will have on the resulting forecasts.

  19. The Radiative Consistency of Atmospheric Infrared Sounder and Moderate Resolution Imaging Spectroradiometer Cloud Retrievals

    NASA Technical Reports Server (NTRS)

    Kahn, Brian H.; Fishbein, Evan; Nasiri, Shaima L.; Eldering, Annmarie; Fetzer, Eric J.; Garay, Michael J.; Lee, Sung-Yung

    2007-01-01

    The consistency of cloud top temperature (Tc) and effective cloud fraction (f) retrieved by the Atmospheric Infrared Sounder (AIRS)/Advanced Microwave Sounding Unit (AMSU) observation suite and the Moderate Resolution Imaging Spectroradiometer (MODIS) on the EOS-Aqua platform are investigated. Collocated AIRS and MODIS TC and f are compared via an 'effective scene brightness temperature' (Tb,e). Tb,e is calculated with partial field of view (FOV) contributions from TC and surface temperature (TS), weighted by f and 1-f, respectively. AIRS reports up to two cloud layers while MODIS reports up to one. However, MODIS reports TC, TS, and f at a higher spatial resolution than AIRS. As a result, pixel-scale comparisons of TC and f are difficult to interpret, demonstrating the need for alternatives such as Tb,e. AIRS-MODIS Tb,e differences ((Delta)Tb,e) for identical observing scenes are useful as a diagnostic for cloud quantity comparisons. The smallest values of DTb,e are for high and opaque clouds, with increasing scatter in (Delta)Tb,e for clouds of smaller opacity and lower altitude. A persistent positive bias in DTb,e is observed in warmer and low-latitude scenes, characterized by a mixture of MODIS CO2 slicing and 11-mm window retrievals. These scenes contain heterogeneous cloud cover, including mixtures of multilayered cloudiness and misplaced MODIS cloud top pressure. The spatial patterns of (Delta)Tb,e are systematic and do not correlate well with collocated AIRS-MODIS radiance differences, which are more random in nature and smaller in magnitude than (Delta)Tb,e. This suggests that the observed inconsistencies in AIRS and MODIS cloud fields are dominated by retrieval algorithm differences, instead of differences in the observed radiances. The results presented here have implications for the validation of cloudy satellite retrieval algorithms, and use of cloud products in quantitative analyses.

  20. Hurricane Katrina as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1: click on image for larger AIRS microwave image

    At 1:30 a.m. local time this morning, the remnants of (now Tropical Depression) Katrina were centered on the Mississippi-Tennessee border. This microwave image from the Atmospheric Infrared Sounder instrument on NASA's Aqua spacecrat shows that the area of most intense precipitation was concentrated to the north of the center of activity.

    The infrared image shows how the storms look through an AIRS Infrared window channel. Window channels measure the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures are associated with high, cold cloud tops that make up the top of the hurricane. The infrared signal does not penetrate through clouds, so the purple color indicates the cool cloud tops of the storm. In cloud-free areas, the infrared signal is retrieved at the Earth's surface, revealing warmer temperatures. Cooler areas are pushing to purple and warmer areas are pushing to red.

    The microwave image (figure 1) reveals where the heaviest precipitation in the hurricane is taking place. The blue areas within the storm show the location of this heavy precipitation. Blue areas outside of the storm where there are moderate or no clouds are where the cold (in the microwave sense) sea surface shines through.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard

  1. Cross-Track Infrared Sounder Science Data Record Pre-launch Calibration and On-Orbit Validation Plans

    NASA Astrophysics Data System (ADS)

    Hagan, D. E.; Bingham, G. E.; Predina, J.; Gu, D.; Sabet-Peyman, F.; Wang, C.; de Amici, G.; Plonski, M.; Farrow, S. V.; Hohn, J.; Esplin, M.; Zavyalov, V.; Fish, C. S.; Glumb, R.; Wells, S.; Suwinski, L.; Strong, J.; Behrens, C.; Kilcoyne, H.; Feeley, J.; Kratz, G.; Tremblay, D. A.

    2009-12-01

    The Cross-Track Infrared Sounder (CrIS) together with the Advanced Technology Microwave Sounder will provide retrievals of atmospheric moisture and temperature profiles for the National Polar-orbiting Operational Environmental Satellite System (NPOESS). The NPOESS is the next generation of low Earth orbiting weather and climate satellites managed by the tri-agency Integrated Program Office, which includes the Department of Commerce, Department of Defense and the National Aeronautics and Space Administration. The CrIS is a Fourier-transform Michelson interferometer covering the spectral range of 3.9 to 15.4 microns (650 to 2550 wavenumbers) developed by ITT under contract to Northrop Grumman Aerospace Systems. The first deployment of the CrIS (Flight Model 1) is scheduled for 2010 on the NPOESS Preparatory Project (NPP) satellite, an early instrument risk reduction component of the NPOESS mission. The analysis and data results from comprehensive TVAC testing of the CrIS FM1 sensor demonstrate a very accurate radiometric and spectral calibration system. We describe instrument performance parameters, and the end-to-end plans and analysis tools for on-orbit verification of sensor characteristics and validation of the SDR radiance products.

  2. Requirements for an Advanced Low Earth Orbit (LEO) Sounder (ALS) for Improved Regional Weather Prediction and Monitoring of Greenhouse Gases

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Susskind, Joel

    2008-01-01

    Hyperspectral infrared atmospheric sounders (e.g., the Atmospheric Infrared Sounder (AIRS) on Aqua and the Infrared Atmospheric Sounding Interferometer (IASI) on Met Op) provide highly accurate temperature and water vapor profiles in the lower to upper troposphere. These systems are vital operational components of our National Weather Prediction system and the AIRS has demonstrated over 6 hrs of forecast improvement on the 5 day operational forecast. Despite the success in the mid troposphere to lower stratosphere, a reduction in sensitivity and accuracy has been seen in these systems in the boundary layer over land. In this paper we demonstrate the potential improvement associated with higher spatial resolution (1 km vs currently 13.5 km) on the accuracy of boundary layer products with an added consequence of higher yield of cloud free scenes. This latter feature is related to the number of samples that can be assimilated and has also shown to have a significant impact on improving forecast accuracy. We also present a set of frequencies and resolutions that will improve vertical resolution of temperature and water vapor and trace gas species throughout the atmosphere. Development of an Advanced Low Earth Orbit (LEO) Sounder (ALS) with these improvements will improve weather forecast at the regional scale and of tropical storms and hurricanes. Improvements are also expected in the accuracy of the water vapor and cloud properties products, enhancing process studies and providing a better match to the resolution of future climate models. The improvements of technology required for the ALS are consistent with the current state of technology as demonstrated in NASA Instrument Incubator Program and NOAA's Hyperspectral Environmental Suite (HES) formulation phase development programs.

  3. Assimilation of Atmospheric InfraRed Sounder (AIRS) Profiles using WRF-Var

    NASA Technical Reports Server (NTRS)

    Zavodsky, Brad; Jedlovec, Gary J.; Lapenta, William

    2008-01-01

    The Weather Research and Forecasting (WRF) model contains a three-dimensional variational (3DVAR) assimilation system (WRF-Var), which allows a user to join data from multiple sources into one coherent analysis. WRF-Var combines observations with a background field traditionally generated using a previous model forecast through minimization of a cost function. In data sparse regions, remotely-sensed observations may be able to improve analyses and produce improved forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. The combined AIRS/AMSU system provides radiance measurements used as input to a sophisticated retrieval scheme which has been shown to produce temperature profiles with an accuracy of 1 K over 1 km layers and humidity profiles with accuracy of 15% in 2 km layers in both clear and partly cloudy conditions. The retrieval algorithm also provides estimates of the accuracy of the retrieved values at each pressure level, allowing the user to select profiles based on the required error tolerances of the application. The purpose of this paper is to describe a procedure to optimally assimilate high-resolution AIRS profile data into a regional configuration of the Advanced Research WRF (ARW) version 2.2 using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background field type using gen_be and an optimal methodology for ingesting AIRS temperature and moisture profiles as separate overland and overwater retrievals with different error characteristics in the WRF-Var. The AIRS thermodynamic profiles are obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm and contain information about the quality of each temperature layer. The quality indicators are used to select the highest quality temperature and moisture

  4. Nighttime Cirrus Detection using Atmospheric Infrared Sounder Window Channels and Total Column Water Vapor

    NASA Technical Reports Server (NTRS)

    Kahn, Brian H.; Liou, Kuo Nan; Lee, Sung-Yung; Fishbein, Evan F.; DeSouza-Machado, Sergio; Eldering, Annmarie; Fetzer, Eric J.; Hannon, Scott E.; Strow, L. Larrabee

    2005-01-01

    A method of cirrus detection at nighttime is presented that utilizes 3.8 and 10.4 (micro)m infrared (IR) window brightness temperature differences (dBT) and total column precipitable water (PW) measurements. This technique is applied to the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit A (AMSU-A) instrument suite on board EOS-Aqua, where dBT is determined from sets of carefully selected AIRS window channels, while PW is derived from the synergistic AIRS and AMSU-A water vapor retrievals. Simulated and observed dBT for a particular value of PW are not constant; several physical factors impact dBT, including the variability in temperature and relative humidity profiles, surface emissivity, instrument noise, and skin/ near-surface air temperature differences. We simulate clear-sky dBT over a realistic range of PWs using 8350 radiosondes that have varying temperature and relative humidity profiles. Thresholds between cloudy and uncertain sky conditions are derived once the scatter in the clear-sky dBT is determined. Simulations of optically thin cirrus indicate that this technique is most sensitive to cirrus optical depth in the 10 (micro)m window of 0.1-0.15 or greater over the tropical and subtropical oceans, where surface emissivity and skin/near-surface air temperature impacts on the IR radiances are minimal. The method at present is generally valid over oceanic regions only, specifically, the tropics and subtropics. The detection of thin cirrus, and other cloud types, is validated using observations at the Atmospheric Radiation Measurement (ARM) program site located at Manus Island in the tropical western Pacific for 89 coincident EOS-Aqua overpasses. Even though the emphasis of this work is on the detection of thin cirrus at nighttime, this technique is sensitive to a broad cloud morphology. The cloud detection technique agrees with ARM-detected clouds 82-84% of the time, which include thin cirrus, as well as other cloud types. Most of

  5. Assimilation of hyperspectral infrared sounder radiances under cloudy skies in a regional NWP model

    NASA Astrophysics Data System (ADS)

    Wang, Pei

    Satellite measurements are an important source of global observations in support of numerical weather prediction (NWP). The assimilation of satellite radiances under clear skies has greatly improved NWP forecast scores. Since most of the data assimilation models are used for the clear radiances assimilation, an important step for satellite radiances assimilation is the clear location detection. Good clear detection could effectively remove the cloud contamination and keep the clear observations for assimilation. In this dissertation, a new detection method uses collocated high spatial resolution imager data onboard the same platform as the satellite sounders to help IR sounders subpixel cloud detection, such as the Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS), the Crosstrack Infrared Sounder (CrIS) and Visible Infrared Imaging Radiometer Suite (VIIRS). The MODIS cloud mask provides a level of confidence for the observed skies to help AIRS Field-of-View (FOVs) cloud detection. By reducing the cloud contamination, a cold bias in the temperature field and a wet bias in the moisture field are corrected for the atmospheric analysis fields. These less cloud affected analysis fields further improve hurricane track and intensity forecast. The availability of satellite observations that can be assimilated in the model is limited if only the clear radiances are assimilation. An effective way to use the thermodynamic information under partially cloudy regions is to assimilate the "cloud-cleared" radiances (CCRs); CCRs are also called clear equivalent radiances. Because the CCRs are the equivalent clear radiances from the partially cloudy FOVs, they can be directly assimilated into the current data assimilation models without modifications. The AIRS CCRs are assimilated and compared with the AIRS using stand-alone cloud detection and collocated cloud detection. The assimilation of AIRS cloud-cleared radiances directly affects

  6. Regional Precipitation Forecast with Atmospheric InfraRed Sounder (AIRS) Profile Assimilation

    NASA Technical Reports Server (NTRS)

    Chou, S.-H.; Zavodsky, B. T.; Jedloved, G. J.

    2010-01-01

    Advanced technology in hyperspectral sensors such as the Atmospheric InfraRed Sounder (AIRS; Aumann et al. 2003) on NASA's polar orbiting Aqua satellite retrieve higher vertical resolution thermodynamic profiles than their predecessors due to increased spectral resolution. Although these capabilities do not replace the robust vertical resolution provided by radiosondes, they can serve as a complement to radiosondes in both space and time. These retrieved soundings can have a significant impact on weather forecasts if properly assimilated into prediction models. Several recent studies have evaluated the performance of specific operational weather forecast models when AIRS data are included in the assimilation process. LeMarshall et al. (2006) concluded that AIRS radiances significantly improved 500 hPa anomaly correlations in medium-range forecasts of the Global Forecast System (GFS) model. McCarty et al. (2009) demonstrated similar forecast improvement in 0-48 hour forecasts in an offline version of the operational North American Mesoscale (NAM) model when AIRS radiances were assimilated at the regional scale. Reale et al. (2008) showed improvements to Northern Hemisphere 500 hPa height anomaly correlations in NASA's Goddard Earth Observing System Model, Version 5 (GEOS-5) global system with the inclusion of partly cloudy AIRS temperature profiles. Singh et al. (2008) assimilated AIRS temperature and moisture profiles into a regional modeling system for a study of a heavy rainfall event during the summer monsoon season in Mumbai, India. This paper describes an approach to assimilate AIRS temperature and moisture profiles into a regional configuration of the Advanced Research Weather Research and Forecasting (WRF-ARW) model using its three-dimensional variational (3DVAR) assimilation system (WRF-Var; Barker et al. 2004). Section 2 describes the AIRS instrument and how the quality indicators are used to intelligently select the highest-quality data for assimilation

  7. Assessment of Infrared Sounder Radiometric Noise from Analysis of Spectral Residuals

    NASA Astrophysics Data System (ADS)

    Dufour, E.; Klonecki, A.; Standfuss, C.; Tournier, B.; Serio, C.; Masiello, G.; Tjemkes, S.; Stuhlmann, R.

    2016-08-01

    For the preparation and performance monitoring of the future generation of hyperspectral InfraRed sounders dedicated to the precise vertical profiling of the atmospheric state, such as the Meteosat Third Generation hyperspectral InfraRed Sounder, a reliable assessment of the instrument radiometric error covariance matrix is needed.Ideally, an inflight estimation of the radiometrric noise is recommended as certain sources of noise can be driven by the spectral signature of the observed Earth/ atmosphere radiance. Also, unknown correlated noise sources, generally related to incomplete knowledge of the instrument state, can be present, so a caracterisation of the noise spectral correlation is also neeed.A methodology, relying on the analysis of post-retreival spectral residuals, is designed and implemented to derive in-flight the covariance matrix on the basis of Earth scenes measurements. This methodology is successfully demonstrated using IASI observations as MTG-IRS proxy data and made it possible to highlight anticipated correlation structures explained by apodization and micro-vibration effects (ghost). This analysis is corroborated by a parallel estimation based on an IASI black body measurement dataset and the results of an independent micro-vibration model.

  8. Calibration of geostationary satellites infrared radiometers using the vertical sounder of a polar orbiting satellite

    NASA Astrophysics Data System (ADS)

    Beriot, N.

    1981-09-01

    A method for the calibration of infrared radiometers of geostationary satellites using calibrated infrared radiometers of an orbiting satellite is presented. This method relies upon similarities between the weighting functions corresponding to the radiometers on geostationary satellites like Meteosat or the GOES series and the weighting functions of some of the channels of the TIROS-N Operational Vertical Sounder (TOVS). It makes use of iso-secant observations of the same scene from both satellites. Many such observations are available every day resulting in a possibly daily calibration curve defined by several hundred of points. This calibration method is shown to be very sensitive, accurate and tractable. This method does not require to collect radiosonde data nor any kind of in-situ experiments and may be completely automatized.

  9. Improved Products for Assimilation and Model Validation from the Atmospheric Infrared Sounder (AIRS) on Aqua

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.

    2008-01-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in the 3.7-15.4 micrometer spectral region with spectral resolution of better than 1200. Key channels from the AIRS Level 1B calibrated radiance product are currently assimilated into operational weather forecasts at NCEP and other international agencies. Additional Level 2 products for assimilation include the AIRS cloud cleared radiances and the geophysical retrieved temperature and water vapor profiles. The AIRS products are also used to validate climate model vertical and horizontal biases and transport of water vapor and key trace gases including Carbon Dioxide and Ozone. The wide variety of products available from the AIRS make it well suited to study processes affecting the interaction of these products.

  10. Validation of the Atmospheric Infrared Sounder (AIRS) over the Antarctic Plateau: Low Radiance, Low Humidity, and Thin Clouds

    NASA Technical Reports Server (NTRS)

    Tobin, David C.

    2005-01-01

    The main goal of the project has been to use specialized measurements collected at the Antarctic Plateau to provide validation of the Atmospheric InfraRed Sounder (AIRS) spectral radiances and some AIRS Level 2 products. As proposed, efforts conducted at the University of Wisconsin are focused on providing technical information, data, and software in support of the validation studies.

  11. The Advanced Technology Microwave Sounder (ATMS): The First 10 Months On-Orbit

    NASA Technical Reports Server (NTRS)

    Kim, Edward; Lyu, C-H Joseph; Blackwell, Willaim; Leslie, R. Vince; Baker, Neal; Mo, Tsan; Sun, Ninghai; Bi, Li; Anderson, Kent; Landrum, Mike; DeAmici, Giovanni; Gu, Degui; Foo, Alex; Ibrahim, Wael; Robinson, Kris; Chidester, Lynn; Shiue, James

    2012-01-01

    The Advanced Technology Microwave Sounder (ATMS) is a new satellite microwave sounding sensor designed to provide operational weather agencies with atmospheric temperature and moisture profile information for global weather forecasting and climate applications. A TMS will continue the microwave sounding capabilities first provided by its predecessors, the Microwave Sounding Unit (MSU) and Advanced Microwave Sounding Unit (AMSU). The first ATMS was launched October 28, 2011 on board the NPOESS Preparatory Project (NPP) satellite. Microwave soundings by themselves are the highest-impact input data used by Numerical Weather Prediction (NWP) models, especially under cloudy sky conditions. ATMS has 22 channels spanning 23-183 GHz, closely following the channel set of the MSU, AMSU-A1/2, AMSU-B, Microwave Humidity Sounder (MHS), and Humidity Sounder for Brazil (HSB). All this is accomplished with approximately 1/4 the volume, 1/2 the mass, and 1/2 the power of the three AMSUs. A description of ATMS cal/val activities will be presented followed by examples of its performance after its first 10 months on orbit.

  12. A Network of Direct Broadcast Antenna Systems to Provide Real-Time Infrared and Microwave Sounder Data for Numerical Weather Prediction

    NASA Astrophysics Data System (ADS)

    Gumley, L.

    2013-12-01

    The Space Science and Engineering Center at the University of Wisconsin-Madison is creating a network of direct broadcast satellite data reception stations to acquire and process infrared and microwave sounder data in real-time from polar orbiting meteorological satellites and deliver the resulting products to NOAA with low latency for assimilation in NCEP numerical weather prediction models. The network will include 4 antenna sites that will be operated directly by SSEC, including Madison WI, Honolulu HI, Miami FL, and Mayaguez PR. The network will also include partner antenna sites not directly controlled by SSEC, including Corvallis OR, Monterey CA, Suitland MD, Fairbanks AK, and Guam. All of the antenna sites will have a combined X/L-band reception system capable of receiving data via direct broadcast from polar orbiting satellites including Suomi NPP and JPSS-1, Metop-A/B, POES,Terra, and Aqua. Each site will collect raw data from these satellites locally, process it to Level 1 (SDR) and Level 2 (EDR) products, and transmit the products back to SSEC for delivery to NOAA/NCEP. The primary purpose of the antenna systems is to provide real-time infrared and microwave sounder data from Metop and Suomi-NPP to NOAA to support data assimilation for NOAA/NCEP operational numerical weather prediction models. At present, NOAA/NCEP use of advanced infrared (CrIS, IASI, AIRS) and microwave (ATMS, AMSU) sounder data over North America in NWP data assimilation is limited because of the latency of the products in relation to the cutoff times for assimilation runs. This network will deliver infrared and microwave sounder data to NCEP with the lowest latency possible, via the reception and processing of data received via direct broadcast. CIMSS/SSEC is managing the procurement and installation of the antenna systems at the two new sites, and will operate the stations remotely. NOAA will establish the reception priorities (Metop and SNPP will be at the highest priority) and

  13. Measurement approach and design of the CubeSat Infrared Atmospheric Sounder (CIRAS)

    NASA Astrophysics Data System (ADS)

    Pagano, Thomas S.; Rider, David; Rud, Mayer; Ting, David; Yee, Karl

    2016-09-01

    The CubeSat Infrared Atmospheric Sounder (CIRAS) will measure upwelling infrared radiation of the Earth in the MWIR region of the spectrum from space on a CubeSat. The observed radiances have information of potential value to weather forecasting agencies and can be used to retrieve lower tropospheric temperature and water vapor globally for weather and climate science investigations. Multiple units can be flown to improve temporal coverage or in formation to provide new data products including 3D atmospheric motion vector winds. CIRAS incorporates key new instrument technologies including a 2D array of High Operating Temperature Barrier Infrared Detector (HOT-BIRD) material, selected for its high uniformity, low cost, low noise and higher operating temperatures than traditional materials. The detectors are hybridized to a commercial ROIC and commercial camera electronics. The second key technology is an MWIR Grating Spectrometer (MGS) designed to provide imaging spectroscopy for atmospheric sounding in a CubeSat volume. The MGS has no moving parts and includes an immersion grating to reduce the volume and reduce distortion. The third key technology is an infrared blackbody fabricated with black silicon to have very high emissivity in a flat plate construction. JPL will also develop the mechanical, electronic and thermal subsystems for CIRAS, while the spacecraft will be a commercially available CubeSat. The integrated system will be a complete 6U CubeSat capable of measuring temperature and water vapor profiles with good lower tropospheric sensitivity. The CIRAS is the first step towards the development of an Earth Observation Nanosatellite Infrared (EON-IR) capable of operational readiness to mitigate a potential loss of CrIS on JPSS or complement the current observing system with different orbit crossing times.

  14. Improved Impact of Atmospheric Infrared Sounder (AIRS) Radiance Assimilation in Numerical Weather Prediction

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Chou, Shih-Hung; Jedlovec, Gary

    2012-01-01

    Improvements to global and regional numerical weather prediction (NWP) have been demonstrated through assimilation of data from NASA s Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Retrieved profiles from AIRS contain much of the information that is contained in the radiances and may be able to reveal reasons for this reduced impact. Assimilating AIRS retrieved profiles in an identical analysis configuration to the radiances, tracking the quantity and quality of the assimilated data in each technique, and examining analysis increments and forecast impact from each data type can yield clues as to the reasons for the reduced impact. By doing this with regional scale models individual synoptic features (and the impact of AIRS on these features) can be more easily tracked. This project examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing operational techniques used for AIRS radiances and research techniques used for AIRS retrieved profiles. Parallel versions of a configuration of the Weather Research and Forecasting (WRF) model with Gridpoint Statistical Interpolation (GSI) that mimics the analysis methodology, domain, and observational datasets for the regional North American Mesoscale (NAM) model run at the National Centers for Environmental Prediction (NCEP)/Environmental Modeling Center (EMC) are run to examine the impact of each type of AIRS data set. The first configuration will assimilate the AIRS radiance data along with other conventional and satellite data using techniques implemented within the operational system; the second configuration will assimilate AIRS retrieved profiles instead of AIRS radiances in the same manner. Preliminary results of this study will be presented and focus on the analysis impact of the radiances and profiles for selected cases.

  15. Hurricane Frances as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS) - Total Water

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Born in the Atlantic, Hurricane Frances became a category 4 hurricane on August 31, 2004. Expectations are the hurricane will hit the Space Coast of Florida in Brevard County early Sunday morning.

    This movie is a time-series of maps that show AIRS observations of the total amount of water vapor present in the atmospheric column above each point of the Earth's surface. If all the water vapor in the column were forced to fall as rain, the depth of the resulting puddle on the surface at that point is equal to the value shown on the map. Fifty millimeters (mm) is about 2 inches. The large band of maximum water vapor in the neighborhood of the equator is the Intertropical Convergence Zone (ITCZ), a region of strong convection and powerful thunderstorms.

    This movie shows the total precipitable water vapor from August 23 through September 2, 2004. You can see Hurricane Frances as it moves through the Caribbean toward Florida, and the changes in intensity are visible. The eye has been marked with a red spot. The water vapor encompassed by the hurricane is also the result of the very strong convection which is an integral part of the formation and intensification of tropical storms. If you look at the last frame of the movie in the lower right corner, you can see the emergence of a new tropical storm. Ivan makes its debut in the Atlantic.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft

  16. Hurricane Frances as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS) and SeaWinds

    NASA Technical Reports Server (NTRS)

    2004-01-01

    this combination image, the AIRS infrared data reveals the temperature of the atmosphere around the storm, but doesn't tell us about the wind direction or relative intensity. The directional vectors of the SeaWinds data set show how the air is circulating around the storm.

    Scatterometers measure surface wind speed and direction by bouncing microwave pulses off the ocean's surface. The SeaWinds instruments measure the backscattered radar energy from wind-generated ocean waves. By making multiple measurements from different looks at the same location, we can infer the vector wind averaged over each 25 km resolution cell. The primary mission objective of the SeaWinds and QuikSCAT scatterometers is to obtain long-term, global coverage of the ocean vector winds for oceanographic and climate research. While not specifically designed for detailed mapping and tracking of hurricanes, both instruments have been found to be useful resources for operational forecasters.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  17. Sensor development in the Shuttle era. [infrared temperature sounders and microwave radiometers

    NASA Technical Reports Server (NTRS)

    Gerding, R. B.; Mantarakis, P. Z.; Webber, D. S.

    1975-01-01

    The use of the Space Shuttle in the development of earth observation sensors is examined. Two sensor classes are selected for case histories: infrared temperature sounders and microwave radiometers. The most significant finding in each of the developmental studies of these two sensor classes is considered to be the feasibility and value of using the Shuttle/Spacelab as a test vehicle for the operation in space of a versatile multimode experimental sensor. The Shuttle Electrically Scanned Microwave Radiometer and the Shuttle Infrared Interferometer are found to be the most effective instruments in this context. The Shuttle/Spacelab Sortie mission characteristics provide opportunities for new approaches to the development of sensors, using the Shuttle as a test vehicle to improve the efficiency of the process with respect to time, cost, and/or quality of the final product. As for crew functions, the short-term Spacelab mission requires some near real-time evaluation of data quality and sensor function in order to insure efficient data collection.

  18. Monthly Representations of Mid-Tropospheric Carbon Dioxide from the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Olsen, Edward T.; Chahine, Moustafa T.; Ruzmaikin, Alexander; Nguyen, Hai; Jiang, Xun

    2011-01-01

    The Atmospheric Infrared Sounder (AIRS) on NASA's Earth Observing System Aqua spacecraft was launched in May of 2002 and acquires hyperspectral infrared spectra used to generate a wide range of atmospheric products including temperature, water vapor, and trace gas species including carbon dioxide. Here we present monthly representations of global concentrations of mid-tropospheric carbon dioxide produced from 8 years of data obtained by AIRS between the years of 2003 and 2010. We define them as "representations" rather than "climatologies" to reflect that the files are produced over a relatively short time period and represent summaries of the Level 3 data. Finally, they have not yet been independently validated. The representations have a horizontal resolution of 2.0 deg x 2.5 deg (Latitude x Longitude) and faithfully reproduce the original 8 years of monthly L3 CO2 concentrations with a standard deviation of 1.48 ppm and less than 2% outliers. The representations are intended for use in studies of the global general circulation of CO2 and identification of anomalies in CO2 typically associated with atmospheric transport. The seasonal variability and trend found in the AIRS CO2 data are discussed.

  19. Performance of the HIRS/2 instrument on TIROS-N. [High Resolution Infrared Radiation Sounder

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1980-01-01

    The High Resolution Infrared Radiation Sounder (HIRS/2) was developed and flown on the TIROS-N satellite as one means of obtaining atmospheric vertical profile information. The HIRS/2 receives visible and infrared spectrum radiation through a single telescope and selects 20 narrow radiation channels by means of a rotating filter wheel. A passive radiant cooler provides an operating temperature of 106.7 K for the HgCdTe and InSb detectors while the visible detector operates at instrument frame temperature. Low noise amplifiers and digital processing provide 13 bit data for spacecraft data multiplexing and transmission. The qualities of system performance that determine sounding capability are the dynamic range of data collection, the noise equivalent radiance of the system, the registration of the air columns sampled in each channel and the ability to upgrade the calibration of the instrument to maintain the performance standard throughout life. The basic features, operating characteristics and performance of the instrument in test are described. Early orbital information from the TIROS-N launched on October 13, 1978 is given and some observations on system quality are made.

  20. Observing Mesoscale Gravity Waves by Tomographic inversion of Infrared Limb-sounder Measurements

    NASA Astrophysics Data System (ADS)

    Ungermann, Joern; Hoffmann, Lars; Preusse, Peter; Kaufmann, Martin; Riese, Martin

    PREMIER is one of three candidates for ESA's 7th Earth Explorer mission that are currently undergoing feasibility studies. The main mission objective is to quantify processes controlling atmospheric composition in the mid/upper troposphere and lower stratosphere, a region of particular importance for climate change. PREMIER will therefore employ the first satellite Fourier transform infrared limb-imager combined with a millimetre-wave limb-sounder. The infrared limb-imager can be operated in a high spatial resolution mode for observations of small-scale structures in atmospheric temperatures and trace gas fields with unprecedented 3D sampling (0.5 km in the vertical direction, 50 km along track, 25 km across track). Global observations of gravity waves (GW) is a major objective of the PREMIER mission. GWs represent an important coupling mechanism for the middle atmosphere. They contribute to the driving of the quasi-biennial oscillation by about 50 %, are the major forcing mechanism of the summer branch of the Brewer-Dobson circulation, and contribute 30 to 50 % to the predicted increase of the Brewer-Dobson circulation due to climate change. GWs are also the main driver of mesospheric winds and cause the cold summer mesopause. We present a fast tomographic retrieval scheme, which is designed to fully exploit the high-resolution radiance observations of the dynamics mode. Based on a detailed analysis of the 'observational filter', we show that the dynamics mode provides unique information on global distributions of gravity waves. For comparison we also applied a conventional one-dimensional retrieval scheme, assuming a homogeneously stratified atmosphere. Based on an analysis of small-and meso-scale temperature wave perturbations (which may arise in the stratosphere due GWs) we find that the two-dimensional approach is much better capable of retrieving these structures. The achievable vertical resolution has values between the vertical sampling (0.5 km) of the

  1. Validation of the Atmospheric Infrared Sounder Water Vapor Retrievals Using Global Positioning System: Case Study in South Korea

    NASA Astrophysics Data System (ADS)

    Won, Jihye; Park, Kwan-Dong; Kim, Dusik; Ha, Jihyun

    2011-12-01

    The atmospheric infrared sounder (AIRS) sensor loaded on the Aqua satellite observes the global vertical structure of atmosphere and enables verification of the water vapor distribution over the entire area of South Korea. In this study, we performed a comparative analysis of the accuracy of the total precipitable water (TPW) provided as the AIRS level 2 standard retrieval product by Jet Propulsion Laboratory (JPL) over the South Korean area using the global positioning system (GPS) TPW data. The analysis TPW for the period of one year in 2008 showed that the accuracy of the data produced by the combination of the Advanced Microwave Sounding Unit sensor with the AIRS sensor to correct the effect of clouds (AIRS-X) was higher than that of the AIRS IR-only data (AIRS-I). The annual means of the root mean square error with reference to the GPS data were 5.2 kg/m2 and 4.3 kg/m2 for AIRS-I and AIRS-X, respectively. The accuracy of AIRS-X was higher in summer than in winter while measurement values of AIRS-I and AIRS-X were lower than those of GPS TPW to some extent.

  2. SI traceable algorithm for characterizing hyperspectral infrared sounder CrIS noise.

    PubMed

    Chen, Yong; Weng, Fuzhong; Han, Yong

    2015-09-10

    The Cross-track Infrared Sounder (CrIS) on the Suomi National Polar-orbiting Partnership Satellite (S-NPP) is a Fourier transform spectrometer and provides the sensor data record (SDR) that can be used to retrieve atmospheric temperature and water vapor profiles and can also be directly assimilated in numerical weather prediction models. The noise equivalent differential radiance (NEdN) is part of CrIS SDR products and represents the amount of random noise in the interferometer data. It is a crucial parameter that affects the accuracy of retrieval and satellite radiance assimilation. In this study, we used the international system of units (SI) traceable method Allan deviation to estimate the CrIS NEdN because the internal calibration target (ICT) radiance was slowly varying with time. Compared to the current standard deviation method, this study shows that the NEdN calculated from Allan deviation is converged to a stable value when a number of samples or the average window size is set to 510. Thus, Allan deviation can result in CrIS NEdN SI traceable noise. An optimal averaging window size is 30 if the NEdN is calculated from the standard deviation.

  3. The Arctic is becoming warmer and wetter as revealed by the Atmospheric Infrared Sounder

    NASA Astrophysics Data System (ADS)

    Boisvert, L. N.; Stroeve, J. C.

    2015-06-01

    Over the past decade, the Arctic has seen unprecedented declines in the summer sea ice area, leading to larger and longer exposed open water areas. The Atmospheric Infrared Sounder is a useful yet underutilized tool to study corresponding atmospheric changes and their feedbacks between 2003 and 2013. Most pronounced warming occurs between November and April, with skin and air temperatures increasing on average 2.5 K and 1.5 K over the Arctic Ocean. In response to sea ice loss, evaporation rates (i.e., moisture flux) increased between August and October by 1.5 × 10-3 g m-2 s-1 (3.8 W m-2 latent heat flux energy), increasing the water vapor feedback and cloud cover. Although most trends are positive over the Arctic Ocean, there is considerable interannual variability. Increasing specific humidity in May and corresponding downward moisture fluxes cause earlier melt onset; warming skin temperatures and radiative responses to increased water vapor and cloud cover in autumn delay freeze-up.

  4. The Transition of Atmospheric Infrared Sounder Total Ozone Products to Operations

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Zavodsky, B. T.; Jedlovec, G. J.

    2014-01-01

    The National Aeronautics and Space Administration Short-term Prediction Research and Transition Center (NASA SPoRT) has transitioned a total column ozone product from the Atmospheric Infrared Sounder (AIRS) retrievals to the Weather Prediction Center and Ocean Prediction Center. The total column ozone product is used to diagnose regions of warm, dry, ozone-rich, stratospheric air capable of descending to the surface to create high-impact non-convective winds. Over the past year, forecasters have analyzed the Red, Green, Blue (RGB) Air Mass imagery in conjunction with the AIRS total column ozone to aid high wind forecasts. One of the limitations of the total ozone product is that it is difficult for forecasters to determine whether elevated ozone concentrations are related to stratospheric air or climatologically high values of ozone in certain regions. During the summer of 2013, SPoRT created an AIRS ozone anomaly product which calculates the percent of normal ozone based on a global stratospheric ozone mean climatology. With the knowledge that ozone values 125 percent of normal and greater typically represent stratospheric air; the anomaly product can be used with the total column ozone product to confirm regions of stratospheric air. This paper describes the generation of these products along with forecaster feedback concerning the use of the AIRS ozone products in conjunction with the RGB Air Mass product to access the utility and transition of the products.

  5. Hurricane Alex as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Carolina, traveling northeast at 6 mph.

    [figure removed for brevity, see original site] August 1, 2004, 1:30am ET Daylight snapshot from AIRS visible/near-infrared. At the time AIRS made this observation, Alex was still a tropical depression and just getting organized.

    Movies Slice down the atmosphere with the AIRS infrared sensor.

    [figure removed for brevity, see original site] August 3, 2004, 1:30am ET Alex becomes the first hurricane of the 2004 North Atlantic season with sustained winds at 75 mph.

    [figure removed for brevity, see original site] August 2, 2004, 1:30pm ET Alex is located about 120 miles southeast of Charleston, South Carolina. Alex has now begun to move to the northeast and a general northeastward track is expected the next couple of days with a gradual acceleration in forward speed as it begins to interact with stronger upper level winds.

    [figure removed for brevity, see original site] August 2, 2004, 1:30am ET Alex now has sustained winds of 35 knots.

    [figure removed for brevity, see original site] August 1, 2004, 1:30pm ET Alex is tropical depression and beginning to get organized.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  6. Improved scheme for Cross-track Infrared Sounder geolocation assessment and optimization

    NASA Astrophysics Data System (ADS)

    Wang, Likun; Zhang, Bin; Tremblay, Denis; Han, Yong

    2017-01-01

    An improved scheme for Cross-track Infrared Sounder (CrIS) geolocation assessment for all scan angles (from -48.5° to 48.5°) is developed in this study. The method uses spatially collocated radiance measurements from the Visible Infrared Imaging Radiometer Suite (VIIRS) image band I5 to evaluate the geolocation performance of the CrIS Sensor Data Records (SDR) by taking advantage of its high spatial resolution (375 m at nadir) and accurate geolocation. The basic idea is to perturb CrIS line-of-sight vectors along the in-track and cross-track directions to find a position where CrIS and VIIRS data matches more closely. The perturbation angles at this best matched position are then used to evaluate the CrIS geolocation accuracy. More importantly, the new method is capable of performing postlaunch on-orbit geometric calibration by optimizing mapping angle parameters based on the assessment results and thus can be further extended to the following CrIS sensors on new satellites. Finally, the proposed method is employed to evaluate the CrIS geolocation accuracy on current Suomi National Polar-orbiting Partnership satellite. The error characteristics are revealed along the scan positions in the in-track and cross-track directions. It is found that there are relatively large errors ( 4 km) in the cross-track direction close to the end of scan positions. With newly updated mapping angles, the geolocation accuracy is greatly improved for all scan positions (less than 0.3 km). This makes CrIS and VIIRS spatially align together and thus benefits the application that needs combination of CrIS and VIIRS measurements and products.

  7. Seven Years of Observations of Mid-Tropospheric CO2 from the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Olsen, Edward T.

    2010-01-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in the 3.7-15.4 um spectral region with spectral resolution of better than 1200. The AIRS was designed to measure temperature and water vapor profiles and cloud properties for improvement in weather forecast and improved parameterization of climate processes. Currently the AIRS Level 1B Radiance Products are assimilated by NWP centers and have shown considerable forecast improvement. Scientists have also demonstrated accurate retrievals of minor gases from AIRS including Carbon Monoxide, Methane, and Ozone. The excellent sensitivity and stability of the AIRS instrument has recently allowed the AIRS team to successfully retrieve Carbon Dioxide (CO2) concentrations in the mid-troposphere (8-10 km) with a horizontal resolution of 100 km and accuracy of 1-2 ppm. The AIRS retrieves over 15,000 measurements per day and can achieve full global coverage in 30 days. The AIRS CO2 accuracy has been validated against a variety of aircraft measurements in the mid-troposphere and upward looking interferometers. Findings from the AIRS data include higher than expected variability in the mid-troposphere, the presence of a belt of CO2 in the southern hemisphere, and numerous observations of atmospheric circulation including the effects of El Nino/La Nina on the CO2 concentrations in the mid-troposphere. The full mid-tropospheric AIRS CO2 data set is now available at the NASA GES/DISC for almost eight years since AIRS has been operational.

  8. Seven years of observations of mid-tropospheric CO 2 from the Atmospheric Infrared Sounder

    NASA Astrophysics Data System (ADS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Olsen, Edward T.

    2011-09-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in the 3.7-15.4 μm spectral region with spectral resolving power of better than 1200. The AIRS was designed to measure temperature and water vapor profiles and cloud properties for improvement in weather forecast and improved parameterization of climate processes. Currently a subset of AIRS Level 1B Radiance Products is assimilated by NWP centers, resulting in significant forecast improvement. Scientists have also demonstrated accurate retrievals of minor gases from AIRS including carbon monoxide, methane, and ozone. The excellent sensitivity and stability of the AIRS instrument has recently allowed the AIRS team to successfully retrieve carbon dioxide (CO 2) concentrations in the mid-troposphere (8-10 km) with a horizontal resolution of 100 km and accuracy better than 2 ppm. The AIRS mid-tropospheric CO 2 yield is 15,000 measurements per 24-h period over land and ocean, day and night for clear and cloudy scenes. The AIRS CO 2 accuracy has been validated against a variety of mid-tropospheric aircraft measurements as well as upward looking interferometers. Findings from the AIRS data include higher than expected variability in the mid-troposphere, the presence of a seasonally variable belt of enhanced CO 2 in the southern hemisphere, and observations of impact of atmospheric dynamics on the CO 2 concentrations in the mid-troposphere including the effects of El Nino/La Nina and the Arctic polar vortex. The full mid-tropospheric AIRS CO 2 data set is now available at the NASA GES/DISC for the 8 year time span since AIRS became operational.

  9. Hurricane Ivan as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    ] September 8, Wednesday, 1:30 am. - microwave, 89GHz

    [figure removed for brevity, see original site] September 10, Friday, 1:30 pm. - infrared, 12micron Ivan closes in on Jamaica. With only 85 miles between the storm and the island, Ivan's winds at category 4 are sustained at 145 mph (230 km/hr). Hurricane-strength winds extend up to 60 miles from the center of Ivan, and tropical-storm force winds are up to 175 miles from the center. Ivan is now better organized and has a well-defined eye. After Ivan leaves Jamaica, it is expected to hit western Cuba, probably making landfall later Sunday as a CAT 4 hurricane.

    [figure removed for brevity, see original site] September 10, Friday, 1:30 pm. - microwave, 89GHz

    [figure removed for brevity, see original site] September 10, Friday, 1:30 pm. - visible/near-infrared

    [figure removed for brevity, see original site] September 13, Friday, 1:30 pm. - infrared, 12micron Ivan's winds at category 5 strength are sustained at 160 mph (260 km/hr) and extend out to 105 miles from the center. Tropical-storm force winds are up to 205 miles from the center. The infrared image shows that the eye has grown quite large - perhaps 40 km (25 miles) across - which is sometimes an indication of weakening but may not be in this case. The surface pressure at the time of this image was estimated by the National Hurricane Center at 915 mb and falling - consistent with a very intense and strengthening hurricane.

    [figure removed for brevity, see original site] September 13, Friday, 1:30 pm. - microwave, 89GHz The microwave image shows that Ivan has again developed two distinct convective centers, separated by about 250 km. That pattern developed on September 5 and persisted for 4 days. It disappeared while the storm was passing over Jamaica, but it has now re-formed.

    [figure removed for brevity, see original site] September 13, Friday, 1:30 pm. - visible/near-infrared

    The Atmospheric Infrared Sounder Experiment, with its

  10. Detection of Ice Polar Stratospheric Clouds from Assimilation of Atmospheric Infrared Sounder Data

    NASA Technical Reports Server (NTRS)

    Stajner, Ivanka; Benson, Craig; Liu, Hui-Chun; Pawson, Steven; Chang, Ping; Riishojgaard, Lars Peter

    2006-01-01

    A novel technique is presented for detection of ice polar stratospheric clouds (PSCs) that form at extremely low temperatures in the lower polar stratosphere during winter. Temperature is a major factor in determining abundance of PSCs, which in turn provide surfaces for heterogeneous chemical reactions leading to ozone loss and radiative cooling. The technique infers the presence of ice PSCs using radiances from the Atmospheric Infrared Sounder (AIRS) in the Goddard Earth Observing System version 5 (GEOS-5) data assimilation system. Brightness temperatures are computed from short-term GEOS-5 forecasts for several hundred AIRS channels, using a radiation transfer module. The differences between collocated AIRS observations and these computed values are the observed-minus-forecast (O-F) residuals in the assimilation system. Because the radiation model assumes clear-sky conditions, we hypothesize that these O-F residuals contain quantitative information about PSCs. This is confirmed using sparse data from the Polar Ozone and Aerosol Measurement (POAM) III occultation instrument. The analysis focuses on 0-F residuals for the 6.79pm AIRS moisture channel. At coincident locations, when POAM III detects ice clouds, the AIRS O-F residuals for this channel are lower than -2K. When no ice PSCs are evident in POAM III data, the AIRS 0-F residuals are larger. Given this relationship, the high spatial density of AIRS data is used to construct maps of regions where 0-F residuals are lower than -2K, as a proxy for ice PSCs. The spatial scales and spatio-temporal variations of these PSCs in the Antarctic and Arctic are discussed on the basis of these maps.

  11. Comparison of Methane Data Products from the TES and AIRS Infrared Sounders

    NASA Astrophysics Data System (ADS)

    Pagano, T. J.; Pagano, T. S.; Worden, J. R.

    2015-12-01

    Methane is the second most powerful greenhouse gas with a highly positive radiative forcing of 0.48 W/m2 (IPCC 2013). Global concentrations of methane have been steadily increasing since 2007 (Bruhwiler 2014), raising concerns about methane's impact on the future global climate. For about the last decade, the Tropospheric Emission Spectrometer (TES) on the Earth Observing System (EOS) Aura spacecraft has been detecting several trace gas species in the troposphere including methane. The goal of this study is to compare TES methane retrievals to that of the Atmospheric Infrared Sounder (AIRS) on the EOS Aqua spacecraft so that scientific investigations may be transferred from TES to AIRS. The two instruments fly in the afternoon constellation (A-Train), providing numerous coincident measurements for comparison. In addition, they also have a similar spectral range, (3.3 to 15.4 µm) for TES (Beer, 2006) and (3.7 to 15.4 µm) for AIRS (Chahine, 2006), making both instruments sensitive to the mid and upper troposphere. This makes them ideal candidates to compare methane data products. However, because AIRS spectral resolution is lower than that of the TES, there may be a difference in vertical sensitivity. In addition, the retrieval techniques and error characteristics are different for the two data sets. The current state of validation for these data products will be presented. To identify conditions in which the data sets agree and dis agree, we present global maps of methane concentrations from monthly level 3 (L3) data products. We also investigate the temporal stability between the two datasets by comparing global zonal averages derived from L3 over the last decade. Finally, we compare L2 retrieval profiles from representative granules in the tropical, mid-latitude and northern latitudes.

  12. Evaluating the Impact of Atmospheric Infrared Sounder (AIRS) Data On Convective Forecasts

    NASA Technical Reports Server (NTRS)

    Kozlowski, Danielle; Zavodsky, Bradley

    2011-01-01

    The Short-term Prediction Research and Transition Center (SPoRT) is a collaborative partnership between NASA and operational forecasting partners, including a number of National Weather Service (NWS) offices. SPoRT provides real-time NASA products and capabilities to its partners to address specific operational forecast challenges. The mission of SPoRT is to transition observations and research capabilities into operations to help improve short-term weather forecasts on a regional scale. Two areas of focus are data assimilation and modeling, which can to help accomplish SPoRT's programmatic goals of transitioning NASA data to operational users. Forecasting convective weather is one challenge that faces operational forecasters. Current numerical weather prediction (NWP) models that operational forecasters use struggle to properly forecast location, timing, intensity and/or mode of convection. Given the proper atmospheric conditions, convection can lead to severe weather. SPoRT's partners in the National Oceanic and Atmospheric Administration (NOAA) have a mission to protect the life and property of American citizens. This mission has been tested as recently as this 2011 severe weather season, which has seen more than 300 fatalities and injuries and total damages exceeding $10 billion. In fact, during the three day period from 25-27 April, 1,265 storms reports (362 tornado reports) were collected making this three day period one of most active in American history. To address the forecast challenge of convective weather, SPoRT produces a real-time NWP model called the SPoRT Weather Research and Forecasting (SPoRT-WRF), which incorporates unique NASA data sets. One of the NASA assets used in this unique model configuration is retrieved profiles from the Atmospheric Infrared Sounder (AIRS).The goal of this project is to determine the impact that these AIRS profiles have on the SPoRT-WRF forecasts by comparing to a current operational model and a control SPoRT-WRF model

  13. Cross-track Infrared Sounder (CrIS) satellite observations of tropospheric ammonia

    NASA Astrophysics Data System (ADS)

    Shephard, M. W.; Cady-Pereira, K. E.

    2015-03-01

    Observations of atmospheric ammonia are important in understanding and modelling the impact of ammonia on both human health and the natural environment. We present a detailed description of a robust retrieval algorithm that demonstrates the capabilities of utilizing Cross-track Infrared Sounder (CrIS) satellite observations to globally retrieval ammonia concentrations. Initial ammonia retrieval results using both simulated and real observations show that (i) CrIS is sensitive to ammonia in the boundary layer with peak vertical sensitivity typically around ~ 850-750 hPa (~ 1.5 to 2.5 km), which can dip down close to the surface (~ 900 hPa) under ideal conditions, (ii) it has a minimum detection limit of ~ 1 ppbv (peak profile value typically at the surface), and (iii) the information content can vary significantly with maximum values of ~ 1 degree-of-freedom for signal. Comparisons of the retrieval with simulated "true" profiles show a small positive retrieval bias of 6% with a standard deviation of ~ ± 20% (ranging from ± 12 to ± 30% over the vertical profile). Note that these uncertainty estimates are considered as lower bound values as no potential systematic errors are included in the simulations. The CrIS NH3 retrieval applied over the Central Valley in CA, USA, demonstrates that CrIS correlates well with the spatial variability of the boundary layer ammonia concentrations seen by the nearby Quantum Cascade-Laser (QCL) in situ surface and the Tropospheric Emission Spectrometer (TES) satellite observations as part of the DISCOVER-AQ campaign. The CrIS and TES ammonia observations show quantitatively similar retrieved boundary layer values that are often within the uncertainty of the two observations. Also demonstrated is CrIS's ability to capture the expected spatial distribution in the ammonia concentrations, from elevated values in the Central Valley from anthropogenic agriculture emissions, to much lower values in the unpolluted or clean surrounding

  14. Large Scale Variability of Mid-Tropospheric Carbon Dioxide as Observed by the Atmospheric Infrared Sounder (AIRS) on the NASA EOS Aqua Platform

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Olsen, Edward T.

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 microns to 15.4 microns and a 13.5 km footprint. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy, water vapor profiles (20%/2km), infrared cloud height and fraction, and trace gas amounts for CO2, CO, SO2, O3 and CH4 in the mid to upper troposphere. AIRS wide swath(cedilla) +/-49.5 deg , enables daily global daily coverage for over 95% of the Earth's surface. AIRS data are used for weather forecasting, validating climate model distribution and processes, and observing long-range transport of greenhouse gases. In this study, we examine the large scale and regional horizontal variability in the AIRS Mid-tropospheric Carbon Dioxide product as a function of season and associate the observed variability with known atmospheric transport processes, and sources and sinks of CO2.

  15. Hurricane Sandy warm-core structure observed from advanced Technology Microwave Sounder

    NASA Astrophysics Data System (ADS)

    Zhu, Tong; Weng, Fuzhong

    2013-06-01

    The warm-core structures of Hurricane Sandy and other nine tropical cyclones (TCs) are studied using the temperatures retrieved from Advanced Technology Microwave Sounder (ATMS). A new algorithm is developed for the retrieval of atmospheric temperature profiles from the ATMS radiances. Since ATMS observation has a higher spatial resolution and better coverage than its predecessor, Advanced Microwave Sounding Unit-A, the retrieved temperature field explicitly resolves TC warm core throughout troposphere and depicts the cold temperature anomalies in the eyewall and spiral rainbands. Unlike a typical TC, the height of maximum warm core of Hurricane Sandy is very low, but the storm size is quite large. Based on the analysis of 10 TCs in 2012, close correlations are found between ATMS-derived warm core and the TC maximum sustained wind (MSW) or minimum sea level pressure (MSLP). The estimation errors of MSW and MSLP from ATMS-retrieved warm core are 13.5 mph and 13.1 hPa, respectively.

  16. Advanced infrared astronomy

    NASA Technical Reports Server (NTRS)

    Kostiuk, Theodor

    1991-01-01

    This task supports the application of infrared heterodyne spectroscopy and other high resolution techniques, as well as infrared arrays to ultra-high resolution studies of molecular constituents of planetary atmospheres. High spectral and spatial resolution measurement and analysis of individual spectral lines permits the retrieval of distributions of atmospheric molecular abundances and temperatures and thus, information on local photochemical processes. Determination of absolute line positions to better than 10(exp -8) permits direct measurement of gas velocities to a few m/sec and thus, the study of dynamics. Observations are made from ground based observatories.

  17. Evaluation of the Impact of Atmospheric Infrared Sounder (AIRS) Radiance and Profile Data Assimilation in Partly Cloudy Regions

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi; Jedlovec, Gary

    2013-01-01

    Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA s Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Retrieved profiles from AIRS contain much of the information that is contained in the radiances and may be able to reveal reasons for this reduced impact. Assimilating AIRS retrieved profiles in an identical analysis configuration to the radiances, tracking the quantity and quality of the assimilated data in each technique, and examining analysis increments and forecast impact from each data type can yield clues as to the reasons for the reduced impact. By doing this with regional scale models individual synoptic features (and the impact of AIRS on these features) can be more easily tracked. This project examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing operational techniques used for AIRS radiances and research techniques used for AIRS retrieved profiles. Parallel versions of a configuration of the Weather Research and Forecasting (WRF) model with Gridpoint Statistical Interpolation (GSI) are run to examine the impact AIRS radiances and retrieved profiles. Statistical evaluation of 6 weeks of forecast runs will be compared along with preliminary results of in-depth investigations for select case comparing the analysis increments in partly cloudy regions and short-term forecast impacts.

  18. Advanced infrared astronomy

    NASA Technical Reports Server (NTRS)

    Kostiuk, T.; Deming, Drake; Mumma, M.

    1988-01-01

    This task supports the application of infrared heterodyne and Fourier transform spectroscopy to ultra-high resolution studies of molecular constituents of planetary astomspheres and cometary comae. High spectral and spatial resolutions are especially useful for detection and study of localized, non-thermal phenomena in low temperature and low density regions, for detection of trace constituents and for measurement of winds and dynamical phenomena such as thermal tides. Measurement and analysis of individual spectial lines permits retrieval of atmospheric molecular abundances and temperatures and thus, information on local photochemical processes. Determination of absolute line positions to better than 10 to the minus eighth power permits direct measurements of gas velocity to a few meters/sec. Observations are made from ground based heterodyne spectrometers at the Kitt Peak McMath solar telescope and from the NASA infrared Telescope Facility on Mauna Kea, Hawaii. Wind velocities at 110km altitude on Venus were extracted approximately 1 m/sec from measurements of non-thermal emission cores of 10.3 micron CO2 lines. Results indicate a subsolar to antisolar circulationwith a small zonal retrograde component.

  19. Case study of the March 24, 1976 Elton, Louisiana tornado using satellite infrared imagery, Doppler sounder, rawinsonde, and radar observations

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Smith, R. E.

    1983-01-01

    The Elton, Louisiana tornado on March 24, 1976 has been studied using GOES digital infrared data for the growth and collapse of the cloud top, the temperature-height relationship and air mass instability from rawinsonde data, gravity waves from Doppler sounder records, and radar summaries from storm activity during the three-hour time period immediately preceding the touchdown of the tornado. In this case, the overshooting turret collapsed 30 minutes before the tornado touchdown as the eastward moving cloud reached Elton, Louisiana. Results show that the gravity waves were excited by the enhanced convection of the storm penetrating through the tropopause in the 2.5 hour time period before the tornado touched down.

  20. Advanced far infrared detectors

    SciTech Connect

    Haller, E.E.

    1993-05-01

    Recent advances in photoconductive and bolometric semiconductor detectors for wavelength 1 mm > {lambda} > 50 {mu}m are reviewed. Progress in detector performance in this photon energy range has been stimulated by new and stringent requirements for ground based, high altitude and space-borne telescopes for astronomical and astrophysical observations. The paper consists of chapters dealing with the various types of detectors: Be and Ga doped Ge photoconductors, stressed Ge:Ga devices and neutron transmutation doped Ge thermistors. Advances in the understanding of basic detector physics and the introduction of modern semiconductor device technology have led to predictable and reliable fabrication techniques. Integration of detectors into functional arrays has become feasible and is vigorously pursued by groups worldwide.

  1. A radiance-based method for estimating uncertainties in the Atmospheric Infrared Sounder (AIRS) land surface temperature product

    NASA Astrophysics Data System (ADS)

    Hulley, Glynn C.; Hook, Simon J.

    2012-10-01

    Land Surface Temperature (LST) has been identified by NASA and other international organizations as an important Earth System Data Record (ESDR). An ESDR is defined as a long-term, well calibrated and validated data set. Identifying uncertainties in LST products with coarse spatial resolutions (>10 km) such as those from hyperspectral infrared sounders is notoriously difficult due to the challenges of making reliable in situ measurements representative of the spatial scales of the output products. In this study we utilize a Radiance-based (R-based) LST method for estimating uncertainties in the Atmospheric Infrared Sounder (AIRS) v5 LST product. The R-based method provides estimates of the true LST using a radiative closure simulation without the need for in situ measurements, and requires input air temperature, relative humidity profiles and emissivity data. The R-based method was employed at three validation sites over the Namib Desert, Gran Desierto, and Redwood National Park for all AIRS observations from 2002 to 2010. Results showed daytime LST root-mean square errors (RMSE) of 2-3 K at the Namib and Desierto sites, and 1.5 K at the Redwood site. Nighttime LST RMSEs at the two desert sites were a factor of two less when compared to daytime results. Positive daytime LST biases were found at each site due to an underestimation of the daytime AIRS v5 longwave spectral emissivity, while the reverse occurred at nighttime. In the AIRS v6 product (release 2012), LST biases and RMSEs will be reduced significantly due to improved methodologies for the surface retrieval and emissivity first guess.

  2. Characterization of geolocation accuracy of Suomi NPP Advanced Technology Microwave Sounder measurements

    NASA Astrophysics Data System (ADS)

    Han, Yang; Weng, Fuzhong; Zou, Xiaolei; Yang, Hu; Scott, Deron

    2016-05-01

    The Advanced Technology Microwave Sounder (ATMS) onboard Suomi National Polar-orbiting Partnership satellite has 22 channels at frequencies ranging from 23 to 183 GHz for probing the atmospheric temperature and moisture under all weather conditions. As part of the ATMS calibration and validation activities, the geolocation accuracy of ATMS data must be well characterized and documented. In this study, the coastline crossing method (CCM) and the land-sea fraction method (LFM) are utilized to characterize and quantify the ATMS geolocation accuracy. The CCM is based on the inflection points of the ATMS window channel measurements across the coastlines, whereas the LFM collocates the ATMS window channel data with high-resolution land-sea mask data sets. Since the ATMS measurements provide five pairs of latitude and longitude data for K, Ka, V, W, and G bands, respectively, the window channels 1, 2, 3, 16, and 17 from each of these five bands are chosen for assessing the overall geolocation accuracy. ATMS geolocation errors estimated from both methods are generally consistent from 40 cases in June 2014. The ATMS along-track (cross-track) errors at nadir are within ±4.2 km (±1.2 km) for K/Ka, ±2.6 km (±2.7 km) for V bands, and ±1.2 km (±0.6 km) at W and G bands, respectively. At the W band, the geolocation errors derived from both algorithms are probably less reliable due to a reduced contrast of brightness temperatures in coastal areas. These estimated ATMS along-track and cross-track geolocation errors are well within the uncertainty requirements for all bands.

  3. Thermal Band Atmospheric Correction Using Atmospheric Profiles Derived from Global Positioning System Radio Occultation and the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagnutti, Mary; Holekamp, Kara; Stewart, Randy; Vaughan, Ronald D.

    2006-01-01

    This Rapid Prototyping Capability study explores the potential to use atmospheric profiles derived from GPS (Global Positioning System) radio occultation measurements and by AIRS (Atmospheric Infrared Sounder) onboard the Aqua satellite to improve surface temperature retrieval from remotely sensed thermal imagery. This study demonstrates an example of a cross-cutting decision support technology whereby NASA data or models are shown to improve a wide number of observation systems or models. The ability to use one data source to improve others will be critical to the GEOSS (Global Earth Observation System of Systems) where a large number of potentially useful systems will require auxiliary datasets as input for decision support. Atmospheric correction of thermal imagery decouples TOA radiance and separates surface emission from atmospheric emission and absorption. Surface temperature can then be estimated from the surface emission with knowledge of its emissivity. Traditionally, radiosonde sounders or atmospheric models based on radiosonde sounders, such as the NOAA (National Oceanic & Atmospheric Administration) ARL (Air Resources Laboratory) READY (Real-time Environmental Application and Display sYstem), provide the atmospheric profiles required to perform atmospheric correction. Unfortunately, these types of data are too spatially sparse and too infrequently taken. The advent of high accuracy, global coverage, atmospheric data using GPS radio occultation and AIRS may provide a new avenue for filling data input gaps. In this study, AIRS and GPS radio occultation derived atmospheric profiles from the German Aerospace Center CHAMP (CHAllenging Minisatellite Payload), the Argentinean Commission on Space Activities SAC-C (Satellite de Aplicaciones Cientificas-C), and the pair of NASA GRACE (Gravity Recovery and Climate Experiment) satellites are used as input data in atmospheric radiative transport modeling based on the MODTRAN (MODerate resolution atmospheric

  4. Global analysis of generation mechanism of ice microphysics inferred from space-borne active sensors and infrared sounder.

    NASA Astrophysics Data System (ADS)

    Okamoto, H.; Sato, K.; Ishimoto, H.; Hagihara, Y.

    2015-12-01

    We examined relationship between ice microphysics and super-saturation by the synergy use of CloudSat cloud radar and CALIPSO lidar and infrared sounder AIRS on Aqua. The retrieval algorithm of ice microphysics was based on Okamoto et al., (2010) but the following improvement was implemented. Ice non-sphericity, orientation and laser pointing angle were considered to estimate scattering properties needed in the analysis of CloudSat and CALIPSO lidar data by the physical optics approximation (Borovoi et al., 2012) and the discrete dipole approximation (Okamoto 2002). Different look up tables were applied for the period of laser-pointing angle of 0.3 degrees off-nadir direction and for the one of 3 degrees off-nadir. Super-saturation was retrieved using 110 temperature and 46 humidity channels of AIRS (Ishimoto 2009 and Ishimoto et al., 2014). The algorithm relied on channel ranking approach to detect clouds by the AIRS information alone so that microwave sounder information was not needed contrary to the AIRS standard product. This achieved three times higher spatial resolution (13.5km) compared with the AIRS standard product so that it is suitable to study super-saturation. We analyzed ice microphysics and super-saturation in the vicinity of the ice clouds to analyze the relation between ice microphysics and super-saturation. AIRS showed relative humidity can reach 160% but majority was below 130%. Super-saturation generally occurred in correspondence with ice clouds. Concept of equivalent ice water content (IWCeq) was introduced as difference between water vapor density and saturation water vapor density. IWCeq was generally larger than IWC. Geophysical patterns between IWCeq and IWC were in good agreement in mid- and high-levels. Global analysis showed IWC increased as IWCeq increased. It was found such relation did not depend on latitudes. Ice formation seemed to occur at about 5 to 10% below relative humidity.

  5. Demonstrating the Operational Value of Atmospheric Infrared Sounder (AIRS) Retrieved Profiles in the Pre-Convective Environment

    NASA Technical Reports Server (NTRS)

    Kozlowski, Danielle M.; Zavodsky, T.; Jedloved, Gary J.

    2011-01-01

    The Short-term Prediction Research and Transition Center (SPoRT) is a collaborative partnership between NASA and operational forecasting partners, including a number of National Weather Service offices. SPoRT provides real-time NASA products and capabilities to its partners to address specific operational forecast challenges. One operational forecast challenge is forecasting convective weather in data-void regions such as large bodies of water (e.g. Gulf of Mexico). To address this forecast challenge, SPoRT produces a twice-daily three-dimensional analysis that blends a model first-guess from the Advanced Research Weather Research and Forecasting (WRF-ARW) model with retrieved profiles from the Atmospheric Infrared Sounder (AIRS) -- a hyperspectral sounding instrument aboard NASA's Aqua satellite that provides temperature and moisture profiles of the atmosphere. AIRS profiles are unique in that they give a three dimensional view of the atmosphere that is not available through the current rawinsonde network. AIRS has two overpass swaths across North America each day, one valid in the 0700-0900 UTC timeframe and the other in the 1900-2100 UTC timeframe. This is helpful because the rawinsonde network only has data from 0000 UTC and 1200 UTC at specific land-based locations. Comparing the AIRS analysis product with control analyses that include no AIRS data demonstrates the value of the retrieved profiles to situational awareness for the pre-convective (and convective) environment. In an attempt to verify that the AIRS analysis was a good representation of the vertical structure of the atmosphere, both the AIRS and control analyses are compared to a Rapid Update Cycle (RUC) analysis used by operational forecasters. Using guidance from operational forecasters, convective available potential energy (CAPE) was determined to be a vital variable in making convective forecasts and is used herein to demonstrate the utility of the AIRS profiles in changing the vertical

  6. Advanced Infrared Photodetectors (Materials Review)

    DTIC Science & Technology

    1993-12-01

    rays by reducing the effective detector area (9]. The lens structure also offers a measure of mechanical protection. 2.3.2 Electronic non...ib.itio’ý I by Availability Codes Philip J. Picone Avail and/ornDist Special SUMMARY The present status of advanced infrared semiconductor detector materials... POSTAL ADDRESS: Director, Surveillance Research Laboratory, PO Box 1500, Salisbury, South Australia, 5108. SRL.0117-RR UNCLASSIFIED SRL - 0117 - RR

  7. Impacts of field of view configuration of Cross-track Infrared Sounder on clear-sky observations.

    PubMed

    Wang, Likun; Chen, Yong; Han, Yong

    2016-09-01

    Hyperspectral infrared radiance measurements from satellite sensors contain valuable information on atmospheric temperature and humidity profiles and greenhouse gases, and therefore are directly assimilated into numerical weather prediction (NWP) models as inputs for weather forecasting. However, data assimilations in current operational NWP models still mainly rely on cloud-free observations due to the challenge of simulating cloud-contaminated radiances when using hyperspectral radiances. The limited spatial coverage of the 3×3 field of views (FOVs) in one field of regard (FOR) (i.e., spatial gap among FOVs) as well as relatively large footprint size (14 km) in current Cross-track Infrared Sounder (CrIS) instruments limits the amount of clear-sky observations. This study explores the potential impacts of future CrIS FOV configuration (including FOV size and spatial coverage) on the amount of clear-sky observations by simulation experiments. The radiance measurements and cloud mask products (VCM) from the Visible Infrared Imager Radiometer Suite (VIIRS) are used to simulate CrIS clear-sky observation under different FOV configurations. The results indicate that, given the same FOV coverage (e.g., 3×3), the percentage of clear-sky FOVs and the percentage of clear-sky FORs (that contain at least one clear-sky FOV) both increase as the FOV size decreases. In particular, if the CrIS FOV size were reduced from 14 km to 7 km, the percentage of clear-sky FOVs increases from 9.02% to 13.51% and the percentage of clear-sky FORs increases from 18.24% to 27.51%. Given the same FOV size but with increasing FOV coverage in each FOR, the clear-sky FOV observations increases proportionally with the increasing sampling FOVs. Both reducing FOV size and increasing FOV coverage can result in more clear-sky FORs, which benefit data utilization of NWP data assimilation.

  8. Cloud thermodynamic phase, cirrus cloud optical thickness and effective diameter in the Version 6 Atmospheric Infrared Sounder data release

    NASA Astrophysics Data System (ADS)

    Kahn, B. H.; Irion, F. W.; Manning, E. M.; Oliphant, R.; Schreier, M. M.; Yue, Q.; Fetzer, E.; Jin, H.; Nasiri, S. L.; Baum, B. A.; Ou, S. S.; Takano, Y.; Liou, K.

    2011-12-01

    The development of a new set of cloud products produced in the upcoming Version 6 release of the Atmospheric Infrared Sounder (AIRS) algorithm is described and initial results are presented. The three new cloud retrieval products include (1) cloud thermodynamic phase, (2) cirrus cloud optical thickness, and (3) cirrus cloud effective diameter. The retrieval methodology of the cirrus cloud parameters is based on an optimal estimation approach that uses Level 1B observed radiances and Level 2 cloud clearing-derived atmospheric profiles that define the atmospheric state, surface temperature and emissivity, and cloud top temperature. The Stand Alone AIRS Radiative Transfer Algorithm (SARTA) is coupled to a delta-4-stream (D4S) approximation (SARTA+D4S) to simulate single-layered cloudy spectra. The same ice scattering models used in the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 5 release are also used in the SARTA+D4S model. The error characterization and averaging kernels associated with the retrieved fields, and various challenges to operational implementation, will be highlighted. Statistical comparisons are made to pixel-scale collocated Aqua MODIS retrievals, with similarities and differences quantified in the AIRS products that are sorted into distinct cloud regimes.

  9. Atmospheric measurements of volcanic eruptions with the infrared sounder IASI (Arne Richter Award for Outstanding Young Scientists Lecture)

    NASA Astrophysics Data System (ADS)

    Clarisse, L.

    2012-04-01

    Due to their spatial coverage, satellite sounders are ideal for measuring volcanic emissions. They are able to monitor (dormant) volcanoes in remote parts of the world and measure large plumes from explosive eruptions. Currently over a dozen instruments (operating in the IR and UV spectral ranges) are capable of detecting volcanic ash and/or sulphur dioxide. Satellite measurements are highly relevant for hazard mitigation, locally but also on large scales for air traffic avoidance of volcanic clouds. Their coverage enables to establish an accurate time-record of global volcanic emissions. This is useful from a volcanology perspective, but also for assessing the global climate impact of volcanic emissions. In this talk we give an overview of four years of measurements of large eruptive plumes from the high resolution infrared atmospheric sounding interferometer (IASI). The focus is on the detection and measurement of volcanic aerosol (volcanic ash, ice and sulphuric acid). In the second part of this talk, we discuss sulphur dioxide measurements and the recent first observations of hydrogen sulphide. We conclude with a discussion of open problems and challenges which lie ahead for the remote sensing of volcanic products.

  10. Development of Infrared and Microwave Techniques for Cloud Parameter Inference from Satellite Imagery and Sounder Data.

    DTIC Science & Technology

    1980-08-30

    clouds and precipitation on the Nimbus VI ESMR channel and the use of ESMR vertical and horizontal polarization components for the determination ot...channels of the Nimbus VI satellite. Random error analyses revealed that the cloud sounding technique employin’g a combiration of infrared and...microwave frequencies appears to be theoretically rigorous and practically workable. Thus, applications of the cloud sounding technique to the Nimbus VI

  11. A Simple Drought Product and Indicator Derived from Temperature and Relative Humidity Observed by the Atmospheric InfraRed Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Granger, S. L.; Behrangi, A.

    2015-12-01

    In the United States, drought results in agricultural losses, impacts to industry, power and energy production, natural resources, municipal water supplies and human health making it one of the costliest natural hazards in the nation. Monitoring drought is therefore critical to help local governments, resource managers, and other groups make effective decisions, yet there is no single definition of drought, and because of the complex nature of drought there is no universal best drought indicator. Remote sensing applications in drought monitoring are advantageous due to the large spatial and temporal frequency of observations, leading to a better understanding of the spatial extent of drought and its duration, and in detecting the onset of drought and its intensity. NASA Earth Observing System (EOS)-era data have potential for monitoring and assessing drought and many are already used either directly or indirectly for drought monitoring. Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) observations from the Moderate Resolution Imaging Spectro-radiometer (MODIS) sensor are widely used for agricultural and environmental plant-stress monitoring via the USDM, the VegDRI project and FEWSNet. However there remain underutilized sources of information from NASA satellite observations that may have promise for characterizing and understanding meteorological drought. Once such sensor is NASA's Advanced Infra-Red Sounder (AIRS) aboard the Aqua satellite. AIRS and it's sister sensor the Advanced Microwave Sounding Unit (AMSU) that together provide meteorological information of high relevance to meteorological drought, e.g., profiles of water vapor, surface air temperature, and precipitation. Recent work undertaken to develop simple indicators of drought based on temperature and relative humidity from the AIRS suite of instruments is promising. Although there are more sophisticated indicators developed through the application of a variety of

  12. Space-borne observation of methane from atmospheric infrared sounder version 6: validation and implications for data analysis

    NASA Astrophysics Data System (ADS)

    Xiong, X.; Weng, F.; Liu, Q.; Olsen, E.

    2015-08-01

    Atmospheric Methane (CH4) is generated as a standard product in recent version of the hyperspectral Atmospheric Infrared Sounder (AIRS-V6) aboard NASA's Aqua satellite at the NASA Goddard Earth Sciences Data and Information Services Center (NASA/GES/DISC). Significant improvements in AIRS-V6 was expected but without a thorough validation. This paper first introduced the improvements of CH4 retrieval in AIRS-V6 and some characterizations, then presented the results of validation using ~ 1000 aircraft profiles from several campaigns spread over a couple of years and in different regions. It was found the mean biases of AIRS CH4 at layers 343-441 and 441-575 hPa are -0.76 and -0.05 % and the RMS errors are 1.56 and 1.16 %, respectively. Further analysis demonstrates that the errors in the spring and in the high northern latitudes are larger than in other seasons or regions. The error is correlated with Degree of Freedoms (DOFs), particularly in the tropics or in the summer, and cloud amount, suggesting that the "observed" spatiotemporal variation of CH4 by AIRS is imbedded with some artificial impact from the retrieval sensitivity in addition to its variation in reality, so the variation of information content in the retrievals needs to be taken into account in data analysis of the retrieval products. Some additional filtering (i.e. rejection of profiles with obvious oscillation as well as those deviating greatly from the norm) for quality control is recommended for the users to better utilize AIRS-V6 CH4, and their implementation in the future versions of the AIRS retrieval algorithm is under consideration.

  13. Advanced uncooled infrared system electronics

    NASA Astrophysics Data System (ADS)

    Neal, Henry W.

    1998-07-01

    Over the past two decades, Raytheon Systems Company (RSC), formerly Texas Instruments Defense Systems & Electronics Group, developed a robust family of products based on a low- cost, hybrid ferroelectric (FE) uncooled focal-plane array (FPA) aimed at meeting the needs for thermal imaging products across both military and commercial markets. Over the years, RSC supplied uncooled infrared (IR) sensors for applications such as in combat vehicles, man-portable weaponry, personnel helmets, and installation security. Also, various commercial IR systems for use in automobiles, boats, law enforcement, hand-held applications, building/site security, and fire fighting have been developed. These products resulted in a high degree of success where cooled IR platforms are too bulky and costly, and other uncooled implementations are less reliable or lack significant cost advantage. Proof of this great success is found in the large price reductions, the unprecedented monthly production rates, and the wide diversity of products and customers realized in recent years. The ever- changing needs of these existing and potential customers continue to fuel the advancement of both the primary technologies and the production capabilities of uncooled IR systems at RSC. This paper will describe a development project intended to further advance the system electronics capabilities of future uncooled IR products.

  14. Observation of the water cycle from space with the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Chahine, M. T.; Waliser, D. E.; Fetzer, E. J.; Olsen, E. T.

    2007-12-01

    AIRS is one of six instruments on board the Aqua satellite, part of NASA's Earth Observing System launched in a sun synchronous near polar orbit on May 4, 2002. AIRS and its partner microwave instrument, AMSU A, provide high quality data facilitating studies of the global water and energy cycles, climate variation and trends, and the response of the climate system to increased greenhouse gases. The exceptional stability of the AIRS instrument provides a climate record of thermal infrared radiance spectra spanning the 3.74 15.4 mm spectral band with 2378 channels at a nominal resolution of 1/1200. (Chahine et al, in BAMS, July 2006) Accurate knowledge of the vertical distribution of water vapor in the atmosphere is critically important to the determination of the warming the Earth will experience as a result of anthropogenic forcing. Comparison of the AIRS specific humidity product to state of the art climate models has shown most models exhibit a pattern of drier than observed (by 10 25%) in the tropics below 800 hPa and moister than observed (by 25 100%) between 300 and 600 hPa in the extra tropics (Pierce et al, GRL 2006). The AIRS water vapor measurements also reveal tropospheric moisture perturbations that are much larger than those depicted in previous NCAR/NCEP reanalysis and ECMWF analysis datasets, both of which have been widely used as observations to validate models. This suggests that the impact of convection induced downdrafts on the atmospheric boundary layer is significantly underestimated in both ECMWF and NCEP reanalysis (Fu et al., GRL 2006). AIRS data have led to the discovery of significant differences in the lower troposphere moisture and temperature fields during the spatial temporal evolution of the Madden Julian Oscillation (MJO). The anomalous lower troposphere temperature structure is observed in detail by AIRS for the Indian and western Pacific Oceans, while it remains much less well defined in the NCEP temperature fields (Tian et al

  15. The Advanced Mars Climate Sounder (AMCS) - A Proven Atmospheric Profiler for Future Mars Orbiters

    NASA Astrophysics Data System (ADS)

    Kleinboehl, A.; Schofield, J. T.; Kass, D. M.; McCleese, D. J.

    2016-10-01

    We describe a mature, low-cost, and low-risk infrared atmospheric profiler based on MRO/MCS heritage for measuring atmospheric temperature, dust, water ice, carbon dioxide ice, and water vapor on a future Mars orbiter mission.

  16. Advanced infrared laser modulator development

    NASA Technical Reports Server (NTRS)

    Cheo, P. K.; Wagner, R.; Gilden, M.

    1984-01-01

    A parametric study was conducted to develop an electrooptic waveguide modulator for generating continuous tunable sideband power from an infrared CO2 laser. Parameters included were the waveguide configurations, microstrip dimensions device impedance, and effective dielectric constants. An optimum infrared laser modulator was established and was fabricated. This modulator represents the state-of-the-art integrated optical device, which has a three-dimensional topology to accommodate three lambda/4 step transformers for microwave impedance matching at both the input and output terminals. A flat frequency response of the device over 20 HGz or = 3 dB) was achieved. Maximum single sideband to carrier power greater than 1.2% for 20 W microwave input power at optical carrier wavelength of 10.6 microns was obtained.

  17. The Atmospheric Infrared Sounder (AIRS) on the NASA Aqua Spacecraft: A General Remote Sensing Tool for Understanding Atmospheric Structure, Dynamics and Composition

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Fetzer, Eric J.

    2010-01-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. Early in the mission, the AIRS instrument demonstrated its value to the weather forecasting community with better than 6 hours of improvement on the 5 day forecast. Now with over eight years of consistent and stable data from AIRS, scientists are able to examine processes governing weather and climate and look at seasonal and interannual trends from the AIRSdata with high statistical confidence. Naturally, long-term climate trends require a longer data set, but indications are that the Aqua spacecraft and the AIRS instrument should last beyond 2018. This paper briefly describes the AIRS data products and presents some of the most significant findings involving the use of AIRS data in the areas of weather forecast improvement, climate processes and model validation, cloud and polar processes, and atmospheric composition (chemistry and dust).

  18. New isostatic mounting concept for a space born Three Mirror Anastigmat (TMA) on the Meteosat Third Generation Infrared Sounder Instrument (MTG-IRS)

    NASA Astrophysics Data System (ADS)

    Freudling, Maximilian; Klammer, Jesko; Lousberg, Gregory; Schumacher, Jean-Marc; Körner, Christian

    2016-07-01

    A novel isostatic mounting concept for a space born TMA of the Meteosat Third Generation Infrared Sounder is presented. The telescope is based on a light-weight all-aluminium design. The mounting concept accommodates the telescope onto a Carbon-Fiber-Reinforced Polymer (CRFP) structure. This design copes with the high CTE mismatch without introducing high stresses into the telescope structure. Furthermore a Line of Sight stability of a few microrads under geostationary orbit conditions is provided. The design operates with full performance at a temperature 20K below the temperature of the CFRP structure and 20K below the integration temperature. The mounting will sustain launch loads of 47g. This paper will provide the design of the Back Telescope Assembly (BTA) isostatic mounting and will summarise the consolidated technical baseline reached following a successful Preliminary Design Review (PDR).

  19. Community Radiative Transfer Model Applications - A Study of the Retrieval of Trace Gases in the Atmosphere from Cross-track Infrared Sounder (CrIS) Data of a Full-spectral Resolution

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Nalli, N. R.; Tan, C.; Zhang, K.; Iturbide, F.; Wilson, M.; Zhou, L.

    2015-12-01

    The Community Radiative Transfer Model (CRTM) [3] operationally supports satellite radiance assimilation for weather forecasting, sensor data verification, and the retrievals of satellite products. The CRTM has been applied to UV and visible sensors, infrared and microwave sensors. The paper will demonstrate the applications of the CRTM, in particular radiative transfer in the retrieva algorithm. The NOAA Unique CrIS/ATMS Processing System (NUCAPS) operationally generates vertical profiles of atmospheric temperature (AVTP) and moisture (AVMP) from Suomi NPP Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) measurements. Current operational CrIS data have reduced spectral resolution: 1.25 cm-1 for a middle wave band and 2.5 cm-1 for a short-wave wave band [1]. The reduced spectral data largely degraded the retrieval accuracy of trace gases. CrIS full spectral data are also available now which have single spectral resolution of 0.625 cm-1 for all of the three bands: long-wave band, middle wave band, and short-wave band. The CrIS full-spectral resolution data is critical to the retrieval of trace gases such as O3, CO [2], CO2, and CH4. In this paper, we use the Community Radiative Transfer Model (CRTM) to study the impact of the CrIS spectral resolution on the retrieval accuracy of trace gases. The newly released CRTM version 2.2.1 can simulates Hamming-apodized CrIS radiance of a full-spectral resolution. We developed a small utility that can convert the CRTM simulated radiance to un-apodized radiance. The latter has better spectral information which can be helpful to the retrievals of the trace gases. The retrievals will be validated using both NWP model data as well as the data collected during AEROSE expeditions [4]. We will also discuss the sensitivity on trace gases between apodized and un-apodized radiances. References[1] Gambacorta, A., et al.(2013), IEEE Lett., 11(9), doi:10.1109/LGRS.2014.230364, 1639-1643. [2] Han, Y., et

  20. Recent advances in miniaturization of infrared spectrometers

    NASA Astrophysics Data System (ADS)

    Daly, James T.; Johnson, Edward A.; Bodkin, W. Andrew; Stevenson, William A.; White, David A.

    2000-03-01

    In the past ten years, a number of miniature spectrometers covering the visible and near infrared wavelengths out to 2.5 microns wavelength have been developed and are now commercially available. These small but high performance instruments have taken advantage of continuing advances in high sensitivity detectors--both CCD's and diode arrays, improvements in holographic gratings, and the availability of low-loss optical materials both in bulk and fiber form that transmit at these wavelengths and that can readily be formed into monolithic shapes for complex optical structures. More recently, a number of researchers have addressed the more intractable problems of extending these miniaturization innovations to spectrometers capable of operation in the mid-infrared wavelengths from 3 microns to 12 microns and beyond. Key enabling technologies for this effort include the recent development of high D*, uncooled thermopile and micro-bolometer detector arrays, new low- mass, high-efficiency pulsed infrared sources, and the design and fabrication of novel monolithic optical structures and waveguides using high index infrared optical materials. This paper reviews the development of these innovative infrared spectrometers and, in particular, the development of the `wedge' spectrometer by Foster-Miller, Inc. and the MicroSpecTM, a MEMS-based solid state spectrograph, by Ion Optics, Inc.

  1. Assessment of error propagation in ultraspectral sounder data via JPEG2000 compression and turbo coding

    NASA Astrophysics Data System (ADS)

    Olsen, Donald P.; Wang, Charles C.; Sklar, Dean; Huang, Bormin; Ahuja, Alok

    2005-08-01

    Research has been undertaken to examine the robustness of JPEG2000 when corrupted by transmission bit errors in a satellite data stream. Contemporary and future ultraspectral sounders such as Atmospheric Infrared Sounder (AIRS), Cross-track Infrared Sounder (CrIS), Infrared Atmospheric Sounding Interferometer (IASI), Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS), and Hyperspectral Environmental Suite (HES) generate a large volume of three-dimensional data. Hence, compression of ultraspectral sounder data will facilitate data transmission and archiving. There is a need for lossless or near-lossless compression of ultraspectral sounder data to avoid potential retrieval degradation of geophysical parameters due to lossy compression. This paper investigates the simulated error propagation in AIRS ultraspectral sounder data with advanced source and channel coding in a satellite data stream. The source coding is done via JPEG2000, the latest International Organization for Standardization (ISO)/International Telecommunication Union (ITU) standard for image compression. After JPEG2000 compression the AIRS ultraspectral sounder data is then error correction encoded using a rate 0.954 turbo product code (TPC) for channel error control. Experimental results of error patterns on both channel and source decoding are presented. The error propagation effects are curbed via the block-based protection mechanism in the JPEG2000 codec as well as memory characteristics of the forward error correction (FEC) scheme to contain decoding errors within received blocks. A single nonheader bit error in a source code block tends to contaminate the bits until the end of the source code block before the inverse discrete wavelet transform (IDWT), and those erroneous bits propagate even further after the IDWT. Furthermore, a single header bit error may result in the corruption of almost the entire decompressed granule. JPEG2000 appears vulnerable to bit errors in a noisy channel of

  2. Cirrus Cloud Properties Derived from High Spectral Resolution Infrared Spectrometry during FIRE II. Part I: The High Resolution Interferometer Sounder (HIS) Systems.

    NASA Astrophysics Data System (ADS)

    Smith, W. L.; Revercomb, H. E.; Knuteson, R. O.; Best, F. A.; Dedecker, R.; Howell, H. B.; Woolf, H. M.

    1995-12-01

    The characteristics of the ER-2 aircraft and ground-based High Resolution Interferometer Sounder (HIS) instruments deployed during FIRE II are described. A few example spectra are given to illustrate the HIS cloud and molecular atmosphere remote sensing capabilities.

  3. Pre-Launch Characterization of the Advanced Technology Microwave Sounder (ATMS) on the Joint Polar Satellite System-1 Satellite (JPSS-1)

    NASA Astrophysics Data System (ADS)

    Kim, Edward; Leslie, Vince; Lyu, Joseph; Smith, Craig; McCormick, Lisa; Anderson, Kent

    2016-04-01

    The Advanced Technology Microwave Sounder (ATMS) is the newest generation of microwave sounder in the international fleet of polar-orbiting weather satellites, replacing the Advanced Microwave Sounding Unit (AMSU) which first entered service in 1998. The first ATMS was launched aboard the Suomi NPP (S-NPP) satellite in late 2011. The second ATMS is manifested on the Joint Polar Satellite System-1 Satellite (JPSS-1). ATMS provides 22 channels of temperature and humidity sounding observations over a frequency range from 23 to 183 GHz. These microwave soundings provide the highest impact data ingested by operational Numerical Weather Prediction (NWP) models, and are the most critical of the polar-orbiting satellite observations, particularly because microwave sensing can penetrate clouds. This paper will present performance characterizations from pre-launch calibration measurements of the JPSS-1 ATMS just completed in December, 2015. The measurements were conducted in a thermal vacuum chamber with blackbody targets simulating cold space, ambient, and a variable Earth scene. They represent the best opportunity for calibration characterization of the instrument since the environment can be carefully controlled. We will present characterizations of the sensitivity (NEDT), accuracy, nonlinearity, noise spectral characteristics, gain stability, repeatability, and inter-channel correlation. An estimate of expected "striping" will be presented, and a discussion of reflector emissivity effects will also be provided. Comparisons will be made with the S-NPP flight unit. Finally, we will describe planned on-orbit characterizations - such as pitch and roll maneuvers - that will further improve both the measurement quality and the understanding of various error contributions.

  4. Sensitivity of thermal infrared sounders to the chemical and micro-physical properties of UTLS secondary sulphate aerosols

    NASA Astrophysics Data System (ADS)

    Sellitto, P.; Legras, B.

    2015-08-01

    Monitoring upper tropospheric-lower stratospheric (UTLS) secondary sulphate aerosols and their chemical and micro-physical properties from satellite nadir observations is crucial to better understand their formation and evolution processes and then to estimate their impact to the UTLS chemistry, and on regional and global radiative balance. Here we present a study aimed at the evaluation of the sensitivity of thermal infrared (TIR) satellite nadir observations to the chemical composition and the size distribution of idealized UTLS sulphate aerosol layers. The extinction properties of sulphuric acid/water droplets, for different sulphuric acid mixing ratios and temperatures, are systematically analysed. The extinction coefficients are derived by means of a Mie code, using refractive indexes taken from the GEISA (Gestion et Étude des Informations Spectroscopiques Atmosphériques: Management and Study of Spectroscopic Information) spectroscopic database and log-normal size distributions with different effective radii and number concentrations. IASI (Infrared Atmospheric Sounding Interferometer) pseudo-observations are generated using forward radiative transfer calculations performed with the 4A (Automatized Atmospheric Absorption Atlas) radiative transfer model, to estimate the impact of the extinction of idealized aerosol layers, at typical UTLS conditions, on the brightness temperature spectra observed by this satellite instrument. We found a marked and typical spectral signature of these aerosol layers between 700 and 1200 cm-1, due to the absorption bands of the sulphate and bi-sulphate ions and the undissociated sulphuric acid, with the main absorption peaks at 1170 and 905 cm-1. The dependence of the aerosol spectral signature to the sulphuric acid mixing ratio, and effective number concentration and radius, as well as the role of interferring parameters like the ozone, sulphur dioxide, carbon dioxide and ash absorption, and temperature and water vapour profile

  5. Verification of mesoscale objective analyses of VAS and rawinsode data using the March 1982 AVE/VAS special network data. [Atmospheric Variability Experiment/Visible-infrared spin-scan radiometer Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Doyle, James D.; Warner, Thomas T.

    1988-01-01

    Various combinations of VAS (Visible and Infrared Spin Scan Radiometer Atmospheric Sounder) data, conventional rawinsonde data, and gridded data from the National Weather Service's (NWS) global analysis, were used in successive-correction and variational objective-analysis procedures. Analyses are produced for 0000 GMT 7 March 1982, when the VAS sounding distribution was not greatly limited by the existence of cloud cover. The successive-correction (SC) Procedure was used with VAS data alone, rawinsonde data alone, and both VAS and rawinsonde data. Variational techniques were applied in three ways. Each of these techniques was discussed.

  6. Investigations of the spatial and temporal resolution of retrievals of atmospheric carbon dioxide from the Atmospheric InfraRed Sounder (AIRS).

    NASA Astrophysics Data System (ADS)

    Maddy, Eric Sean

    As the dominant anthropogenic greenhouse gas, carbon dioxide (CO 2), represents an important component of climate change (IPCC 2007). Owing to burning of fossil fuels and deforestation, atmospheric CO2 concentrations have increased over 110 parts-per-million by volume (ppmv) from 270 ppmv to 380 ppmv since the dawn of the Industrial Revolution. Understanding of the spatial distribution of the sources and sinks of atmospheric CO 2 is necessary not only to predict the future atmospheric abundances but also their effect on future climate. Although designed for deriving high precision temperature and moisture profiles, NASA's Atmospheric InfraRed Sounder (AIRS) IR measurements include broad vertical sensitivity (between 3 and 10 km) to atmospheric CO2 variations. Coupled with AIRS' broad swath pattern and a technique referred to as "cloud-clearing" these measurements enable daily global spatial coverage. Nevertheless, AIRS' ability to determine the spatial distribution of carbon dioxide (CO2) is strongly dependent on its ability to separate the radiative effects of CO2 from temperature not to mention measurement uncertainties due to clouds and other geophysical variables such as moisture and ozone. This research presents a thorough investigation into the temporal and spatial scales that the AIRS can separate temperature (and other geophysical variables) from CO2. Through our detailed understanding of the way satellites view the Earth's atmosphere, we have developed an algorithm capable of retrieving global middle-to-upper tropospheric CO2 concentrations in all-weather conditions with total uncertainties ranging between 1 to 2 ppmv. From a radiative perspective, roughly equivalent to 30 mK to 60 mK, 1 to 2 ppmv, is an awesome feat for a space-borne sensor. Necessary for the remarkable performance of this algorithm, we developed methodologies capable of separating the radiative effect of CO2 variability from temperature, improved the fast rapid transmittance algorithm

  7. Phenomenological Modeling of Infrared Sources: Recent Advances

    NASA Technical Reports Server (NTRS)

    Leung, Chun Ming; Kwok, Sun (Editor)

    1993-01-01

    Infrared observations from planned space facilities (e.g., ISO (Infrared Space Observatory), SIRTF (Space Infrared Telescope Facility)) will yield a large and uniform sample of high-quality data from both photometric and spectroscopic measurements. To maximize the scientific returns of these space missions, complementary theoretical studies must be undertaken to interpret these observations. A crucial step in such studies is the construction of phenomenological models in which we parameterize the observed radiation characteristics in terms of the physical source properties. In the last decade, models with increasing degree of physical realism (in terms of grain properties, physical processes, and source geometry) have been constructed for infrared sources. Here we review current capabilities available in the phenomenological modeling of infrared sources and discuss briefly directions for future research in this area.

  8. Mars Climate Sounder (Artist's Concept)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This artist's concept of NASA's Mars Reconnaissance Orbiter at Mars features one of its instruments -- the Mars Climate Sounder -- in action. Using nine channels across the visible and thermal infrared ranges of the spectrum, the Mars Climate Sounder looks first at space through the atmosphere above the horizon of Mars to get a vertical profile with temperature, pressure, dust and water vapor concentration measurements every 5 kilometers (3 miles) vertically from the ground to about 80 kilometers (about 50 miles) high. It also looks down onto the planet to get surface temperature and column abundances of dust and water vapor between the spacecraft and the surface.

    These 'profiles' and surface measurements are combined into daily, three-dimensional global weather maps for both daytime and nighttime. Observations will be made through the martian year to characterize the large seasonal variations in atmospheric dust loading, humidity and thermal structure, providing scientists with the same type of information meteorologists use to understand and predict weather and climate here on Earth.

  9. Commercialization of Australian advanced infrared technology

    NASA Astrophysics Data System (ADS)

    Redpath, John; Brown, Allen; Woods, William F.

    1995-09-01

    For several decades, the main thrust in infrared technology developments in Australia has been in two main sensor technologies: uncooled silicon chip printed bolometric sensors pioneered by DSTO's Kevin Liddiard, and precision engineered high quality Cadmium Mercury Telluride developed at DSTO under the guidance of Dr. Richard Hartley. In late 1993 a low cost infrared imaging device was developed at DSTO as a sensor for guided missiles. The combination of these three innovations made up a unique package that enabled Australian industry to break through the barriers of commercializing infrared technology. The privately owned company, R.J. Optronics Pty Ltd undertook the process of re-engineering a selection of these DSTO developments to be applicable to a wide range of infrared products. The first project was a novel infrared imager based on a Palmer scan (translated circle) mechanism. This device applies a spinning wedge and a single detector, it uses a video processor to convert the image into a standard rectangular format. Originally developed as an imaging seeker for a stand-off weapon, it is producing such high quality images at such a low cost that it is now also being adapted for a wide variety of other military and commercial applications. A technique for electronically stabilizing it has been developed which uses the inertial signals from co-mounted sensors to compensate for platform motions. This enables it to meet the requirements of aircraft, marine vessels and masthead sight applications without the use of gimbals. After tests on a three-axis motion table, several system configurations have now been successfully operated on a number of lightweight platforms, including a Cessna 172 and the Australian made Seabird Seeker aircraft.

  10. Advanced components for spaceborne infrared astronomy

    NASA Technical Reports Server (NTRS)

    Davidson, A. W.

    1984-01-01

    The need for improved cryogenic components to be used in future spaceborne infrared astronomy missions was identified. Improved low noise cryogenic amplifiers operated with infrared detectors, and better cryogenic actuators and motors with extremely low power dissipation are needed. The feasibility of achieving technological breakthroughs in both of these areas was studied. An improved silicon junction field effect transistor (JFET) could be developed if: (1) high purity silicon; (2) optimum dopants; and (3) very high doping levels are used. The feasibility of a simple stepper motor equipped with superconducting coils is demonstrated by construction of such a device based on a standard commercial motor. It is found that useful levels of torque at immeasurably low power levels were achieved. It is concluded that with modest development and optimization efforts, significant performance gains is possible for both cryogenic preamplifiers and superconducting motors and actuators.

  11. High power infrared QCLs: advances and applications

    NASA Astrophysics Data System (ADS)

    Patel, C. Kumar N.

    2012-01-01

    QCLs are becoming the most important sources of laser radiation in the midwave infrared (MWIR) and longwave infrared (LWIR) regions because of their size, weight, power and reliability advantages over other laser sources in the same spectral regions. The availability of multiwatt RT operation QCLs from 3.5 μm to >16 μm with wall plug efficiency of 10% or higher is hastening the replacement of traditional sources such as OPOs and OPSELs in many applications. QCLs can replace CO2 lasers in many low power applications. Of the two leading groups in improvements in QCL performance, Pranalytica is the commercial organization that has been supplying the highest performance QCLs to various customers for over four year. Using a new QCL design concept, the non-resonant extraction [1], we have achieved CW/RT power of >4.7 W and WPE of >17% in the 4.4 μm - 5.0 μm region. In the LWIR region, we have recently demonstrated QCLs with CW/RT power exceeding 1 W with WPE of nearly 10 % in the 7.0 μm-10.0 μm region. In general, the high power CW/RT operation requires use of TECs to maintain QCLs at appropriate operating temperatures. However, TECs consume additional electrical power, which is not desirable for handheld, battery-operated applications, where system power conversion efficiency is more important than just the QCL chip level power conversion efficiency. In high duty cycle pulsed (quasi-CW) mode, the QCLs can be operated without TECs and have produced nearly the same average power as that available in CW mode with TECs. Multiwatt average powers are obtained even in ambient T>70°C, with true efficiency of electrical power-to-optical power conversion being above 10%. Because of the availability of QCLs with multiwatt power outputs and wavelength range covering a spectral region from ~3.5 μm to >16 μm, the QCLs have found instantaneous acceptance for insertion into multitude of defense and homeland security applications, including laser sources for infrared

  12. Advances in Detector Technology for Infrared Astronomy

    NASA Technical Reports Server (NTRS)

    McCreight, Craig; Cheng, P. L. (Technical Monitor)

    1995-01-01

    Progress in semiconductor materials and processing technology has allowed the development of infrared detector arrays with unprecedented sensitivity, for imaging and spectroscopic applications in astronomy. The earlier discrete-detector approach has been replaced by large-element (up to 1024 x 1024 pixel), multiplexed devices. Progress has been made against a number of key limiting factors, such as quantum efficiency, noise, spectral response, linearity, and dark current. Future developments will focus on the need for even larger arrays, which operate at higher temperatures.

  13. Full Spectral Resolution Data Generation from the Cross-track Infrared Sounder on S-NPP at NOAA and its Use to Investigate Uncertainty in Methane Absorption Band Near 7.66 µm

    NASA Astrophysics Data System (ADS)

    Xiong, X.; Peischl, J.; Ryerson, T. B.; Sasakawa, M.; Han, Y.; Chen, Y.; Wang, L.; Tremblay, D.; Jin, X.; Zhou, L.; Liu, Q.; Weng, F.; Machida, T.

    2015-12-01

    The Cross-track Infrared Sounder (CrIS) on Suomi National Polar-orbiting Partnership Satellite (S-NPP) is a Fourier transform spectrometer for atmospheric sounding. CrIS on S-NPP started to provide measurements in 1305 channels in its normal mode since its launch on November 2011 to December 4, 2014, and after that it was switched to the full spectral resolution (FSR) mode, in which the spectral resolutions are 0.625 cm-1 in all the MWIR (1210-1750 cm-1), SWIR (2155-2550 cm-1) and the LWIR bands (650-1095 cm-1) with a total of 2211 channels. While the NOAA operational Sensor Data Record (SDR) processing (IDPS) continues to produce the normal resolution SDRs by truncating full spectrum RDR data, NOAA STAR started to process the FSR SDRs data since December 4, 2014 to present, and the data is being delivered through NOAA STAR website (ftp://ftp2.star.nesdis.noaa.gov/smcd/xxiong/). The current FSR processing algorithm was developed on basis of the CrIS Algorithm Development Library (ADL), and is the baseline of J-1 CrIS SDR algorithm. One major benefit to use the FSR data is to improve the retrieval of atmospheric trace gases, such as CH4, CO and CO2 . From our previous studies to retrieve CH4 using Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI), it was found the uncertainty in the CH4 absorption band is up to 1-2%. So, in this study we computed the radiance using the community radiative transfer model (CRTM) and line-by-line model, with the inputs of "truth" of atmospheric temperature and moisture profiles from ECMWF model (and/or RAOB sounding) and CH4 profiles from in-situ aircraft measurements, then convoluted with the response function of CrIS. The difference between the simultaed radiance and the collocated CrIS FSR data is used to exam the uncertainty in these strong absorption channels.Through the improved fitting to the transmittance in these channels, it is expected to improve the retrieval of CH4 using CrIS on S

  14. Hurricane Debby - An illustration of the complementary nature of VAS soundings and cloud and water vapor motion winds. [Visible Infrared Spin Scan Radiometer Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Le Marshall, J. F.; Smith, W. L.; Callan, G. M.

    1985-01-01

    The utility of VISSR Atmospheric Sounder (VAS) temperature and moisture soundings and cloud and water vapor motion winds in defining a storm and its surroundings at subsynoptic scales has been examined using a numerical analysis and prognosis system. It is shown that the VAS temperature and moisture data, which specify temperature and moisture well in cloud-free areas, are complemented by cloud and water vapor motion data generated in the cloudy areas. The cloud and water vapor 'winds' provide thermal gradient information for interpolating the soundings across cloudy regions. The loss of analysis integrity due to the reduction of VAS sounding density in the cloudy regions associated with synoptic activity is ameliorated by using cloud and water vapor motion winds. The improvement in numerical forecasts resulting from the addition of these data to the numerical analysis is recorded.

  15. Variational assimilation of VAS data into a mesoscale model Assimilation method and sensitivity experiments. [Visible Infrared Spin-Scan Radiometer Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Cram, J. M.; Kaplan, M. L.

    1985-01-01

    The assimilation of temperature and moisture gradient information from the Visible IR Spin-Scan Radiometer's Atmospheric Sounder (VAS) into a mesoscale model is presently undertaken by means of a variational method and followed by tests of the sensitivity of both diabatic and adiabatic versions of the model to VAS data assimilations for the case of July 20-21, 1981. The synoptic scale effects of the assimilation of VAS data are noted to be negligible; the greatest impact was instead on mesoscale forecasts of convective instability patterns. The additional assimilation of relative humidity gradients did not significantly change the patterns of the forecast instabilities. The greatest improvements from assimilation resulted from the resolution of the strong mesoscale temperature gradients by the asynoptic VAS data.

  16. Low-level water vapor fields from the VISSR atmospheric sounder (VAS) split window channels at 11 and 12 microns. [visible infrared spin scan radiometer

    NASA Technical Reports Server (NTRS)

    Chesters, D.; Uccellini, L.; Robinson, W.

    1982-01-01

    A series of high-resolution water vapor fields were derived from the 11 and 12 micron channels of the VISSR Atmospheric Sounder (VAS) on GOES-5. The low-level tropospheric moisture content was separated from the surface and atmospheric radiances by using the differential adsorption across the 'split window' along with the average air temperature from imbedded radiosondes. Fields of precipitable water are presented in a time sequence of five false color images taken over the United States at 3-hour intervals. Vivid subsynoptic and mesoscale patterns evolve at 15 km horizontal resolution over the 12-hour observing period. Convective cloud formations develop from several areas of enhanced low-level water vapor, especially where the vertical water vapor gradient relatively strong. Independent verification at radiosonde sites indicates fairly good absolute accuracy, and the spatial and temporal continuity of the water vapor features indicates very good relative accuracy. Residual errors are dominated by radiometer noise and unresolved clouds.

  17. A VAS-numerical model impact study using the Gal-Chen variational approach. [Visible Infrared Spin-Scan Radiometer Atmospheric Sounder (VAS)

    NASA Technical Reports Server (NTRS)

    Aune, Robert M.; Uccellini, Louis W.; Peterson, Ralph A.; Tuccillo, James J.

    1987-01-01

    Numerical experiments to assess the impact of incorporating temperature data from the VISSR Atmospheric Sounder (VAS) using the assimilation technique developed by Gal-Chen (1986) modified for use in the Mesoscale Atmospheric Simulation System (MASS) model were conducted. The scheme is designed to utilize the high temporal and horizontal resolution of satellite retrievals while maintaining the fine vertical structure generated by the model. This is accomplished by adjusting the model lapse rates to reflect thicknesses retrieved from VAS and applying a three-dimensional variational that preserves the distribution of the geopotential fields in the model. A nudging technique whereby the model temperature fields are gradually adjusted toward the updated temperature fields during model integration is also tested. An adiabatic version of MASS is used in all experiments to better isolate mass-momentum imbalances. The method has a sustained impact over an 18 hr model simulation.

  18. Sensor System Performance Evaluation and Benefits from the NPOESS Airborne Sounder Testbed-Interferometer (NAST-I)

    NASA Technical Reports Server (NTRS)

    Larar, A.; Zhou, D.; Smith, W.

    2009-01-01

    Advanced satellite sensors are tasked with improving global-scale measurements of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring, and environmental change detection. Validation of the entire measurement system is crucial to achieving this goal and thus maximizing research and operational utility of resultant data. Field campaigns employing satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft are an essential part of this validation task. The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed-Interferometer (NAST-I) has been a fundamental contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This paper focuses on some of the challenges associated with validating advanced atmospheric sounders and the benefits obtained from employing airborne interferometers such as the NAST-I. Select results from underflights of the Aqua Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) obtained during recent field campaigns will be presented.

  19. Space View Issues for Hyperspectral Sounders

    NASA Technical Reports Server (NTRS)

    Manning, Evan M.; Aumann, Hartmut H.; Broberg, Steven E.

    2013-01-01

    The expectation for climate quality measurements from hyperspectral sounders is absolute calibration accuracy at the 100 mK level and stability at the < 40 mK/decade level. The Atmospheric InfraRed Sounder (AIRS)1, Cross-track Infrared Sounder (CrIS), and Infrared Atmospheric Sounding Interferometer (IASI) hyperspectral sounders currently in orbit have been shown to agree well over most of their brightness temperature range. Some larger discrepancies are seen, however, at the coldest scene temperatures, such as those seen in Antarctic winter and deep convective clouds. A key limiting factor for the calibrated scene radiance accuracy for cold scenes is how well the effective radiance of the cold space view pertains to the scene views. The space view signal is composed of external sources and instrument thermal emission at about 270 K from the scan mirror, external baffles, etc. Any difference in any of these contributions between space views and scene views will impact the absolute calibration accuracy, and the impact can be critical for cold scenes. Any change over time in these will show up as an apparent trend in calibrated radiances. We use AIRS data to investigate the validity of the space view assumption in view of the 100 mK accuracy and 40 mK/decade trend expectations. We show that the space views used for the cold calibration point for AIRS v5 Level-1B products meet these standards except under special circumstances and that AIRS v6 Level-1B products will meet them under all circumstances. This analysis also shows the value of having multiple distinct space views to give operational redundancy and analytic data, and that reaching climate quality requires continuing monitoring of aging instruments and adjustment of calibration.

  20. Advances in applications and methodology for aerial infrared thermography

    NASA Astrophysics Data System (ADS)

    Stockton, Gregory R.

    2004-04-01

    Most aerial infrared (IR) is performed by the military, but there are commercial uses. Some of these non-military applications are the focus of this paper. Generally speaking, the farther away one can get from the object of an infrared survey, while maintaining the needed spatial resolution and thermal sensitivity, the more usable the data is. Wide areas and large objects can be effectively imaged from the air. In fact, the use of high-resolution aerial infrared imagery is often the only way that one can see slight nuances of temperature differences and trace the patterns of heat. In order to produce an easy to understand, high quality and useable report, the data must be acquired, recorded and processed in an efficient and effective way. This paper discusses the ongoing advances in methodology, platform and equipment required to produce high quality usable data for the end-user.

  1. Advances in Mid-Infrared Spectroscopy for Chemical Analysis

    NASA Astrophysics Data System (ADS)

    Haas, Julian; Mizaikoff, Boris

    2016-06-01

    Infrared spectroscopy in the 3-20 μm spectral window has evolved from a routine laboratory technique into a state-of-the-art spectroscopy and sensing tool by benefitting from recent progress in increasingly sophisticated spectra acquisition techniques and advanced materials for generating, guiding, and detecting mid-infrared (MIR) radiation. Today, MIR spectroscopy provides molecular information with trace to ultratrace sensitivity, fast data acquisition rates, and high spectral resolution catering to demanding applications in bioanalytics, for example, and to improved routine analysis. In addition to advances in miniaturized device technology without sacrificing analytical performance, selected innovative applications for MIR spectroscopy ranging from process analysis to biotechnology and medical diagnostics are highlighted in this review.

  2. Advanced indium antimonide monolithic charge coupled infrared imaging arrays

    NASA Technical Reports Server (NTRS)

    Koch, T. L.; Merilainen, C. A.; Thom, R. D.

    1981-01-01

    The continued process development of SiO2 insulators for use in advanced InSb monolithic charge coupled infrared imaging arrays is described. Specific investigations into the use of plasma enhanced chemical vapor deposited (PECVD) SiO2 as a gate insulator for InSb charge coupled devices is discussed, as are investigations of other chemical vapor deposited SiO2 materials.

  3. Growth And Characterization Studies Of Advanced Infrared Heterostructures

    DTIC Science & Technology

    2015-06-30

    Research Laboratory AFRL /RVSS Space Vehicles Directorate 3550 Aberdeen Ave., SE 11. SPONSOR/MONITOR’S REPORT Kirtland AFB, NM 87117-5776 NUMBER(S... Kirtland AFB, NM 87117-5776 2 cys Official Record Copy AFRL /RVSS/Christian Morath 1 cy ... AFRL -RV-PS- TR-2015-0126 AFRL -RV-PS- TR-2015-0126 GROWTH AND CHARACTERIZATION STUDIES OF ADVANCED INFRARED HETEROSTRUCTURES Sanjay Krishna

  4. Advances in submicron infrared vibrational band chemical imaging

    NASA Astrophysics Data System (ADS)

    Dragnea, Bogdan; Leone, Stephen R.

    The technique of infrared near-field microscopy with submicron resolution is an important addition to the chemical sciences arsenal in the last few years. Although related to highly successful scanning optical probe microscopies in the visible, infrared near-field microscopy had to overcome several obstacles, which slowed its development. This review illustrates the history as well as the state of the art of this new field, its limitations and perspectives. At present, two main experimental approaches have been successful: the apertureless metal tip approach and the fibre tip aperture approach. The two variants are compared from the point of view of resolution, ease of implementation in the laboratory and image formation mechanisms. The techniques using chemically specific vibrational absorption contrast are emphasized here, in the general context of chemical microscopy, which includes other methods such as chemical force, Raman and fluorescence microscopies. The phenomenon of surface-enhanced infrared absorption is also mentioned in relation to near-field infrared microscopy, with regard to important aspects of image formation and possible improvements. The main advantages of spatial resolution, chemical sensitivity, non-intrusiveness, minute amounts of specimen and the possibility of quantitative analytical measurements make infrared near-field microscopy a powerful tool. We also examine here possible future applications that go beyond the limits of classical vibrational microspectroscopy, as well as directions for additional advances.

  5. Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Zavodsky, B. T.; Folmer, M. J.; Jedlovec, G. J.

    2014-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), 32-km North American Regional Reanalysis (NARR) interpolated to a 12-km grid, and 13-km Rapid Refresh analyses.

  6. Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Zavodsky, B. T.; Jedlovec, G. J.

    2014-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis, and Rapid Refresh analyses.

  7. The Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary; Elmer, Nicholas

    2013-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis, and Rapid Refresh analyses.

  8. Impact of the Assimilation of Hyperspectral Infrared Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, Emily B.; Zavodsky, Bradley T; Jedlovec, Gary J.; Elmer, Nicholas J.

    2013-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), North American Regional Reanalysis (NARR) reanalysis, and Rapid Refresh analyses.

  9. A Moderate-resolution Geosynchronous Microwave Sounder

    NASA Technical Reports Server (NTRS)

    Shiue, James

    2004-01-01

    The introduction of microwave radiometers for remote sensing of atmospheric temperature and humidity began in early 1970s, when NASA's Nimbus series experimental satellites tested a number of microwave payloads which are the precursors of today's operational microwave temperature and humidity sounders such as the Advanced Microwave Sounding Unit (AMSU-A and AMSU-B), now flying on several Lower Earth Orbiting (LEO) satellites, notably the National Oceanic and Atmospheric (NOAA)-series weather satellites. The Advanced Technology Microwave Sounder (ATMS) will be the next generation microwave sounder, now being developed by NASA for the future U.S. National Polar-orbiting Operational Environmental Satellites System (NPOESS), slated for operation late this decade. The unique feature of a microwave sensor is its cloud-penetrating capability. And the visible and IR sensors are usually greatly degraded by cloud covers. But under the cloud cover is where the weather can be most "active," and atmospheric measurements are most urgently needed. This unique capability has been well proven by AMSU-A, and AMSU-B on LEO satellites. The same capability is also true for a microwave sounder on a GEO satellite. The key advantage of a sensor on a GEO-platform is its "high temporal resolution." A sensor on a GEO-platform can almost "continuous" monitor a given scene on Earth. On the other hand, the major drawback the GEO-platform is its poor spatial resolution. This is probably the main reason why a geosynchronous microwave sounder has yet to be realized. Take the ATMS as an example. It has a 20 cm diameter antenna (temperature channels), producing a 2.2 degree beam, resulting in a footprint of 32 km (from the NPOESS 833 km orbit). From a GEO-orbit the same 32 km footprint would need an antenna 43 times larger, or 860 cm diameter. We will discuss the needs and advantages of such a GEO-microwave sounder with a straw-man design, and show the expected performance characteristics, such as

  10. A Microwave Pressure Sounder

    NASA Technical Reports Server (NTRS)

    Flower, D. A.; Peckham, G. E.

    1978-01-01

    An instrument to measure atmospheric pressure at the earth's surface from an orbiting satellite would be a valuable addition to the expanding inventory of remote sensors. The subject of this report is such an instrument - the Microwave Pressure Sounder (MPS). It is shown that global-ocean coverage is attainable with sufficient accuracy, resolution and observational frequency for meteorological, oceanographic and climate research applications. Surface pressure can be deduced from a measurement of the absorption by an atmospheric column at a frequency in the wing of the oxygen band centered on 60 GHz. An active multifrequency instrument is needed to make this measurement with sufficient accuracy. The selection of optimum operating frequencies is based upon accepted models of surface reflection, oxygen, water vapor and cloud absorption. Numerical simulation using a range of real atmospheres defined by radiosonde observations were used to validate the frequency selection procedure. Analyses are presented of alternative system configurations that define the balance between accuracy and achievable resolution.

  11. Middle Atmosphere Sounder and Thermal Emission Radiometer - Master

    NASA Astrophysics Data System (ADS)

    Mlynczak, M. G.; Scott, D. K.; Esplin, R. W.; Bailey, S. M.; Randall, C. E.

    2014-12-01

    The Middle Atmosphere Sounder and Thermal Emission Radiometer (MASTER) instrument is an advanced infrared limb-scanning instrument designed to measure the thermal structure, chemical composition, and energy balance from the stratosphere to the lower thermosphere. MASTER builds on NASA's long and successful heritage of infrared limb scanners including the LIMS, HIRDLS, and SABER instruments. MASTER has exceptional radiometric sensitivity with a more efficient, compact, and lightweight design. An updated focal plane enables critical new science in the areas of the carbon budget closure, geomagnetically-driven ozone destruction, and auroral energy deposition, while virtually eliminating out of band contributions via dual filtering. MASTER will continue the SABER-TIMED and EOS-Aura records of temperature, lower stratospheric water vapor, ozone, methane, and thermospheric cooling by nitric oxide and carbon dioxide. MASTER's size and mass are specifically designed to allow flexibility in the choice of small satellite buses and low cost launch vehicles. The expanded focal plane enables a choice of channels applicable to science objectives in NASA's Earth Science and Heliophysics enterprises. Due to the long and successful heritage the MASTER instrument is at an exceptionally high technology readiness level. No new technologies are required to build the MASTER flight instrument.

  12. Flight evaluation of advanced third-generation midwave infrared sensor

    NASA Astrophysics Data System (ADS)

    Shen, Chyau N.; Donn, Matthew

    1998-08-01

    In FY-97 the Counter Drug Optical Upgrade (CDOU) demonstration program was initiated by the Program Executive Office for Counter Drug to increase the detection and classification ranges of P-3 counter drug aircraft by using advanced staring infrared sensors. The demonstration hardware is a `pin-for-pin' replacement of the AAS-36 Infrared Detection Set (IRDS) located under the nose radome of a P-3 aircraft. The hardware consists of a 3rd generation mid-wave infrared (MWIR) sensor integrated into a three axis-stabilized turret. The sensor, when installed on the P- 3, has a hemispheric field of regard and analysis has shown it will be capable of detecting and classifying Suspected Drug Trafficking Aircraft and Vessels at ranges several factors over the current IRDS. This paper will discuss the CDOU system and it's lab, ground, and flight evaluation results. Test targets included target templates, range targets, dedicated target boats, and targets of opportunity at the Naval Air Warfare Center Aircraft Division and at operational test sites. The objectives of these tests were to: (1) Validate the integration concept of the CDOU package into the P-3 aircraft. (2) Validate the end-to-end functionality of the system, including sensor/turret controls and recording of imagery during flight. (3) Evaluate the system sensitivity and resolution on a set of verified resolution targets templates. (4) Validate the ability of the 3rd generation MWIR sensor to detect and classify targets at a significantly increased range.

  13. Thin-film infrared absorber structures for advanced thermal detectors

    NASA Astrophysics Data System (ADS)

    Parsons, A. D.; Pedder, D. J.

    1988-06-01

    Imaging thermal detector technology is a rapidly advancing field in which the current emphasis is towards the development of very large arrays of very small pyroelectric detector elements. For maximum responsivity, each of the thin pyroelectric elements in an array must be provided with a thermal absorber to convert incoming infrared radiation into heat. This paper describes one such absorber structure, comprising a thin metal film, impedance matched to free space, and a quarter-wave polymer film which offers an acceptably low thermal mass. The structure and properties of this thin-film absorber are compared with those of an electroplated platinum black absorber commonly used in thermal detectors. The theory of the absorber is presented and good agreement is shown between calculated and experimentally derived absorption spectra.

  14. First Data from Mars Climate Sounder

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The Mars Climate Sounder, an instrument on NASA's Mars Reconnaissance Orbiter designed to monitor daily changes in the global atmosphere of Mars, made its first observations of Mars on March 24, 2006.

    These tests were conducted to demonstrate that the instrument could, if needed, support the mission's aerobraking maneuvers (dips into the atmosphere to change the shape of the orbit) by providing hemisphere-scale coverage of atmospheric activity. The instrument scanned nine arrays of detectors four times across the entire disc of the planet, including the north pole, from an altitude of about 45,000 kilometers (28,000 miles). This is about 150 times farther away than the spacecraft will be during its main science phase. At this great range, the planet appears only 40 pixels wide, as suggested by the pixilation of the images. However, this is sufficient to identify regional dust storms in the lower atmosphere. Regional dust storms could perturb atmospheric densities at the higher altitudes (about 100 kilometers or 60 miles) where the orbiter will conduct more than 500 aerobraking passes during the next six months. Such storms are rare in the current season on Mars, early northern spring, and no large storms are present as the orbiter prepares for the start of aerobraking.

    Each of the Mars Climate Sounder's arrays looks in a different wavelength band, and three of the resulting images are shown here. The view on the left is from data collected in a broad spectral band (wavelengths of 0.3 microns to 3 microns) for reflected sunlight. The view in the center is from data collected in the 12-micron thermal-infrared band. This band was chosen to sense infrared radiation from the surface when the atmosphere is clear and from dust clouds when it is not. The view on the right is from data collected at 15 microns, a longer-wavelength band still in the thermal-infrared part of the spectrum. At this wavelength, carbon dioxide, the main ingredient in Mars

  15. [Advances in infrared spectrum zoom imaging system research].

    PubMed

    Bai, Yu; Xing, Ting-wen; Jiang, Ya-dong

    2014-12-01

    Compared with the infrared spectrum fixed focal length system and infrared spectrum dual-zoom system, infrared spectrum continuous zoom imaging system which has continuous variational field of view can track targets sequentially, so it is a research direction in infrared spectrum imaging technology. Some new technologies are presented overseas in order to improve the detection performance, reduce cost and have good athermalized performance in infrared spectrum continuous zoom imaging system. Infrared material, infrared detector and variable aperture, those new technologies are su mmarized and the idiographic application of those new technologies in infrared spectrum continuous zoom imaging system are presented in the paper, for example athermalization of an infrared spectrum zoom lens system with new infrared material for target detection, dual band infrared spectrum continuous zoom imaging system with mid-wave infrared and long-wave infrared, infrared spectrum continuous zoom imaging system with high ratio, nfrared spectrum continuous zoom imaging system with dual F/number. It is useful for the development of chinese infrared continuous zoom imaging system.

  16. Laser atmospheric wind sounder (LAWS)

    NASA Technical Reports Server (NTRS)

    Beranek, R. G.; Bilbro, J. W.; Fitzjarrald, D. E.; Jones, W. D.; Keller, V. W.

    1989-01-01

    The principle of operation of a space based Doppler lidar wind measuring system is discussed along with laser wavelength selection considerations. Differences in accommodating the Laser Atmospheric Wind Sounder (LAWS) on the Earth Observing System (EOS) polar platform and the Manned Space Station are presented. The impact of the LAWS instrument support subsystems are specifically discussed.

  17. Advanced infrared detection and image processing for automated bat censusing

    NASA Astrophysics Data System (ADS)

    Frank, Jeffery D.; Kunz, Tomas H.; Horn, Jason; Cleveland, Cutler; Petronio, Susan M.

    2003-09-01

    The Brazilian free-tailed bat (Tadarida brasiliensis) forms some of the largest aggregations of mammals known to mankind. However, little is known about population sizes and nightly foraging activities. An advanced infrared (IR) thermal imaging system with a real time imaging and data acquisition system is described for censusing Brazilian free-tailed bats during nightly emergences at selected Texas caves. We developed a statistically-based algorithm suitable for counting emerging bats in columns with relative constant trajectories and velocities. Individual bats are not identified and tracked, but instead column density is calculated at intervals of 1/30th of a second and counts are accumulated based upon column velocity. Preliminary evaluation has shown this method to be far more accurate than those previously used to census large bat populations. This real-time automated censusing system allows us to make accurate and repeatable estimates of the number of bats present independent of colony size, ambient light, or weather conditions, and without causing disturbance to the colony.

  18. A study of a 63 K radiative cooler for the advanced moisture and temperature sounder. [earth-orbiting IR spectrometer for atmospheric measurements

    NASA Technical Reports Server (NTRS)

    Salazar, R.; Evans, N.

    1981-01-01

    A study was performed of cooling methods for a space-borne, earth observing infrared optical instrument, AMTS. Major requirements on the thermal design are an optics temperature below 200 K, a detector array temperature below 75 K, orbital lifetime of 3 to 5 years, a near polar, sun synchronous orbit with altitude near 800 km. Power dissipation of the detectors is 38 mW, in the optics compartment 1.4 W. Large radiative coolers positioned so as to be shielded from sun, spacecraft and earth result in predicted optics temperature of 156 K and detector temperature of 63 K.

  19. The Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Brendt. Emily; Zavodsky, Bradley; Jedlovec, Gary; Elmer, Nicholas

    2014-01-01

    Tropopause folds are identified by warm, dry, high-potential vorticity, ozone-rich air and are one explanation for damaging non-convective wind events. Could improved model representation of stratospheric air and associated tropopause folding improve non-convective wind forecasts and high wind warnings? The goal of this study is to assess the impact of assimilating Hyperspectral Infrared (IR) profiles on forecasting stratospheric air, tropopause folds, and associated non-convective winds: (1) AIRS: Atmospheric Infrared Sounder (2) IASI: Infrared Atmospheric Sounding Interferometer (3) CrIMSS: Cross-track Infrared and Microwave Sounding Suite

  20. Assimilation of the Microwave Limb Sounder Radiances

    NASA Technical Reports Server (NTRS)

    Wargan, K.; Read, W.; Livesey, N.; Wagner, P.; Nguyen. H.; Pawson, S.

    2012-01-01

    It has been shown that the assimilation of limb-sounder data can significantly improve the representation of ozone in NASA's GEOS Data Assimilation Systems (GEOS-DAS), particularly in the stratosphere. The studies conducted so far utilized retrieved data from the MIPAS, POAM, ILAS and EOS Microwave Limb Sounder (EOS MLS) instruments. Direct assimilation of the radiance data can be seen as the natural next step to those studies. The motivation behind working with radiances is twofold. First, retrieval algorithms use a priori data which are either climatological or are obtained from previous analyses. This introduces additional uncertainty and, in some cases, may lead to "self-contamination"- when the a priori is taken from the same assimilation system in which subsequently ingests the retrieved observations. Second, radiances can be available in near real time thus providing an opportunity for operational assimilation, which could help improve the use of infrared radiance instruments from operational satellite instruments. In this presentation we summarize our ongoing work on an implementation of the assimilation of EOS MLS radiances into the GEOS-5 DAS. This work focuses on assimilation of band 7 brightness temperatures which are sensitive to ozone. Our implementation uses the MLS Callable Forward Model developed by the MLS team at NASA JPL as the observation operator. We will describe our approach and recent results which are not yet final. In particular, we will demonstrate that this approach has a potential to improve the vertical structure of ozone in the lower tropical stratosphere as compared with the retrieved MLS product. We will discuss the computational efficiency of this implementation.

  1. Advances in Organic Near-Infrared Materials and Emerging Applications.

    PubMed

    Qi, Ji; Qiao, Wenqiang; Wang, Zhi Yuan

    2016-06-01

    Much progress has been made in the field of research on organic near-infrared materials for potential applications in photonics, communications, energy, and biophotonics. This account mainly describes our research work on organic near-infrared materials; in particular, donor-acceptor small molecules, organometallics, and donor-acceptor polymers with the bandgaps less than 1.2 eV. The molecular designs, structure-property relationships, unique near-infrared absorption, emission and color/wavelength-changing properties, and some emerging applications are discussed.

  2. High-resolution Interferometer Sounder (HIS), phase 2

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The High-resolution Interferometer Sounder (HIS) was successfully built, tested, and flight proven on the NASA U-2/ER-2 high altitude aircraft. The HIS demonstration has shown that, by using the technology of Fourier Transform Spectroscopy (FTS), it is possible to measure the spectrum of upwelling infrared radiance needed for temperature and humidity sounding with high spectral resolution and high radiometric precision. By resolving individual carbon dioxide lines, the retrieved temperature profiles have vertical resolutions of 1 to 2 km and RMS errors less than 1 C, about 2 to 4 times better than possible with current sounders. Implementing this capability on satellite sounders will greatly enhance the dynamical information content of temperature measurements from space. The aircraft model HIS is now a resource which should be used to support field experiments in mesoscale meteorology, to monitor trace gas concentrations and to better understand their effects on climate, to monitor the surface radiation budget and the radiative effects of clouds, and to collect data for research into retrieval techniques, especially under partially cloudy conditions.

  3. Advanced Moisture and Temperature Sounder (AMTS) study

    NASA Technical Reports Server (NTRS)

    Kaplan, L. D.; Isaacs, R. G.; Worsham, R. D.; Deblonde, G.

    1985-01-01

    Retrieval of tropospheric humidity profiles from satellite-based upwelling radiances are shown to be improved by using physical methods for obtaining first-guess profiles as well as for inverting the radiative transfer equation by relaxation. The first guess is based on an empirically verified hypothesis, from theoretical considerations, that the brightness temperature corresponding to the radiance should be approximately equal to the actual temperatue at a channel-invariant optical depth provided that the surface and stratospheric contributions to the radiance are small. Even greater improvement of retrieved humidity profiles can be accomplished by increasing the number of channels used and by selecting their spectral location and bandpass to obtain sharper independent weighting functions. For example, the AMTS system, with high resolution water channels at 1650, 1700, 1839, 1850 and 1930 cm, is shown to be capable of reducing the retrieved water vapor errors in 200 mb thick layers by a factor of two or three relative to the HIRS-2 system errors. Expected AMTS errors in tropical layer water content are particularly low, less than 20% at all levels, and of the order of 10% or less in the middle troposphere.

  4. Rapid infrared joining takes on the advanced materials

    NASA Astrophysics Data System (ADS)

    Blue, C. A.; Warrier, S. G.; Robson, M. T.; Lin, R. Y.

    1993-06-01

    In this work, 4340 steel was joined with a nickel-based brazing alloy AMS 4777, using rapid infrared joining technique (Blue et al., 1991), and the microstructure of the joint was examined using SEM. The effects of the bond thickness and the joint lap area on the bond shear strength were investigated following the ASTM D1002-72 standard joint testing procedure. Results of SEM examination indicated that the microstructure of the material was preserved throughout the joining process. Bond shear tests showed that, as the bond thickness increases, the shear strength also increases, reaching a constant bond strength plateau at about 2 mils. It is concluded that, compared with traditional joining methods, the rapid infrared joining technique has the advantages of fast heating, little energy consumption, easy operation, no need for vacuum, little metallurgical modification to the base metal, and low cost.

  5. Advanced semiconductor quantum well devices for infrared applications

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Vladimir V.

    High performance mid-wavelength infrared (MWIR) light emitting diodes (LEDs) are needed for chemical sensing, analysis and medical imaging. Efficient long wavelength infrared (LWIR) photodetectors are highly desirable for remote sensing and space exploration. The goal of this work is to investigate new mid-infrared LEDs and to optimize existing LWIR quantum well infrared photodetectors (QWIPs). Type-II "W" InAs/InGaSb/AlGaAsSb quantum wells were incorporated as optically active layers in MWIR LEDs. Influence of MBE crystal growth conditions on the density of Shockley-Read-Hall centers in the "W" quantum wells was studied and the optimal growth conditions were identified. A qualitative physical model was developed to describe relative importance of the radiative and non-radiative processes for various temperature ranges. MWIR LED structures lattice-matched to InAs and GaSb substrates were grown. Devices on InAs substrates were found to be at least twice as efficient as devices grown on GaSb. LEDs on InAs had 4.5 mum emission wavelength and 26.5 muW/A external efficiency. Possibility to operate GaAs/AIGaAs QWIP under normal-to-surface light incidence was studied. Metal nano-particle surface coating was developed and processes responsible for, light coupling into the QWIP were investigated. QWIP structure itself was optimized to eliminate Si-diffusion-assisted dark current enhancement by employing a new doping profile in the quantum wells. Devices with the new doping profile had an order of magnitude lower dark current and 20% higher photoresponse than commercially available QWIPs.

  6. From Aircraft to GEO: Using Microwave Sounders to Observe the Atmosphere

    NASA Astrophysics Data System (ADS)

    Lambrigtsen, B.; Brown, S.; Gaier, T.; Tanner, A.; Kangaslahti, P.; Lim, B.; Tanabe, J.

    2010-12-01

    Although hyperspectral infrared sounders, such as AIRS and IASI, have become important weather and climate sensors for both operational and research use, microwave sounders, in spite of their coarser spatial resolution and poorer sounding accuracy, still play a crucial role. That is because infrared sounders do not sample certain weather and climate regimes well, particularly those associated with full cloud cover and storms. In part one this paper we review recent results obtained with the High Altitude MMIC Sounding Radiometer (HAMSR), an aircraft-based microwave sounder developed at the Jet Propulsion Laboratory and recently deployed on the NASA Global Hawk unmanned aircraft as part of the NASA Genesis and Rapid Intensification Processes (GRIP) hurricane field campaign. Here the emphasis is on the benefits of the high spatial resolution that is possible with suborbital sensors. In part two we will review plans to deploy a microwave sounder on a geostationary satellite in the relatively near future, where the emphasis is on the high temporal resolution that is possible from GEO. We focus on the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) now being developed at JPL for the Precipitation and All-weather Temperature and Humidity (PATH) mission - one of the 15 missions recommended by the National Research Council in its recent “decadal survey” of Earth satellite missions.

  7. GEOSTAR - a microwave sounder for GOES-R

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn; Wilson, William; Tanner, Alan

    2005-01-01

    The National Oceanic and Atmospheric Administration (NOAA) has for many years operated two weather satellite systems, the Polar-orbiting Operational Environmental Satellite system (POES), using low-earth orbiting (LEO) satellites, and the Geostationary Operational Environmental Satellite system (GOES), using geostationary earth orbiting (GEO) satellites. Similar systems are also operated by other nations. The POES satellites have been equipped with both infrared (IR) and microwave (MW) atmospheric sounders, which together make it possible to determine the vertical distribution of temperature and humidity in the troposphere even under cloudy conditions.

  8. Thermal Infrared Imaging Spectrometer - An advanced optics technology instrument

    NASA Technical Reports Server (NTRS)

    Mahoney, Colin; Labaw, Clayton; Sobel, Harold; Kahle, Anne

    1990-01-01

    Through the use of a special optical filter, the Thermal Infrared Imaging Spectrometer, an airborne multispectral IR imaging instrument operating in the thermal emission region (7.5-14 microns), will achieve signal-to-noise ratios greater than 600 with ambient temperature optics. This instrument will be used to do compositional surface mapping of the terrain, and will refine the ability to categorize rock families and types by providing much higher spectral resolution in the emission region than was previously available. Details of the optical system, the detector, the cooler system, and the support electronics are described.

  9. Infrared Spectral Radiance Intercomparisons With Satellite and Aircraft Sensors

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  10. Advanced Image Processing for Defect Visualization in Infrared Thermography

    NASA Technical Reports Server (NTRS)

    Plotnikov, Yuri A.; Winfree, William P.

    1997-01-01

    Results of a defect visualization process based on pulse infrared thermography are presented. Algorithms have been developed to reduce the amount of operator participation required in the process of interpreting thermographic images. The algorithms determine the defect's depth and size from the temporal and spatial thermal distributions that exist on the surface of the investigated object following thermal excitation. A comparison of the results from thermal contrast, time derivative, and phase analysis methods for defect visualization are presented. These comparisons are based on three dimensional simulations of a test case representing a plate with multiple delaminations. Comparisons are also based on experimental data obtained from a specimen with flat bottom holes and a composite panel with delaminations.

  11. Submillimeter Planetary Atmospheric Chemistry Exploration Sounder

    NASA Technical Reports Server (NTRS)

    Schlecht, Erich T.; Allen, Mark A.; Gill, John J.; Choonsup, Lee; Lin, Robert H.; Sin, Seth; Mehdi, Imran; Siegel, Peter H.; Maestrini, Alain

    2013-01-01

    Planetary Atmospheric Chemistry Exploration Sounder (SPACES), a high-sensitivity laboratory breadboard for a spectrometer targeted at orbital planetary atmospheric analysis. The frequency range is 520 to 590 GHz, with a target noise temperature sensitivity of 2,500 K for detecting water, sulfur compounds, carbon compounds, and other atmospheric constituents. SPACES is a prototype for a powerful tool for the exploration of the chemistry and dynamics of any planetary atmosphere. It is fundamentally a single-pixel receiver for spectral signals emitted by the relevant constituents, intended to be fed by a fixed or movable telescope/antenna. Its front-end sensor translates the received signal down to the 100-MHz range where it can be digitized and the data transferred to a spectrum analyzer for processing, spectrum generation, and accumulation. The individual microwave and submillimeter wave components (mixers, LO high-powered amplifiers, and multipliers) of SPACES were developed in cooperation with other programs, although with this type of instrument in mind. Compared to previous planetary and Earth science instruments, its broad bandwidth (approx. =.13%) and rapid tunability (approx. =.10 ms) are new developments only made possible recently by the advancement in submillimeter circuit design and processing at JPL.

  12. Infrared

    NASA Astrophysics Data System (ADS)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  13. RF Charging of Topside Sounder Spacecraft

    NASA Astrophysics Data System (ADS)

    James, H. G.

    1998-11-01

    Evidence concerning RF-induced charging of topside sounder spacecraft is reviewed. The most direct evidence from the orbital sounders ISIS II and Cosmos 1809 is observations of sounder-accelerated ions at energies up to a several tens of electron-volts. These ions are interpreted as the flux to the spacecraft body to discharge the negative electrical potential induced on the body by the action of sounder near fields on ambient electrons. The situation on ISIS II was modeled for frequencies well below the electron plasma and gyrofrequencies, fp and fc , respectively. During the RF pulse, the body was found to go to a negative potential about equal to the peak amplitude of the voltage waveform applied to the sounder dipole. Other observations from the sounders at frequencies around fp and fc, including "floating" resonant signals on ionograms and impedance measurements, attest to RF sheaths and hence to charging. The OEDIPUS-C spacecraft potential measurement has provided proof of RF charging through the whole range of electron characteristic frequencies.

  14. Full Spatial Resolution Infrared Sounding Application in the Preconvection Environment

    NASA Astrophysics Data System (ADS)

    Liu, C.; Liu, G.; Lin, T.

    2013-12-01

    Advanced infrared (IR) sounders such as the Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI) provide atmospheric temperature and moisture profiles with high vertical resolution and high accuracy in preconvection environments. The derived atmospheric stability indices such as convective available potential energy (CAPE) and lifted index (LI) from advanced IR soundings can provide critical information 1 ; 6 h before the development of severe convective storms. Three convective storms are selected for the evaluation of applying AIRS full spatial resolution soundings and the derived products on providing warning information in the preconvection environments. In the first case, the AIRS full spatial resolution soundings revealed local extremely high atmospheric instability 3 h ahead of the convection on the leading edge of a frontal system, while the second case demonstrates that the extremely high atmospheric instability is associated with the local development of severe thunderstorm in the following hours. The third case is a local severe storm that occurred on 7-8 August 2010 in Zhou Qu, China, which caused more than 1400 deaths and left another 300 or more people missing. The AIRS full spatial resolution LI product shows the atmospheric instability 3.5 h before the storm genesis. The CAPE and LI from AIRS full spatial resolution and operational AIRS/AMSU soundings along with Geostationary Operational Environmental Satellite (GOES) Sounder derived product image (DPI) products were analyzed and compared. Case studies show that full spatial resolution AIRS retrievals provide more useful warning information in the preconvection environments for determining favorable locations for convective initiation (CI) than do the coarser spatial resolution operational soundings and lower spectral resolution GOES Sounder retrievals. The retrieved soundings are also tested in a regional data assimilation WRF 3D-var system to evaluate the

  15. Multiorder etalon sounder (MOES) development and test for balloon experiment

    NASA Technical Reports Server (NTRS)

    Hays, Paul B.; Wnag, Jinxue; Wu, Jian

    1993-01-01

    The Fabry-Perot interferometer (FPI), with its high throughput and high spectral resolution has been used in the remote-sensing measurements of the earth's atmospheric composition, winds, and temperatures. The most recent satellite instruments include the Fabry-Perot interferometer flown on the Dynamics Explorer-2 (DE-2), the High Resolution Doppler Imager (HRDI), and the Cryogenic Limb Array Etalon Spectrometer (CLAES) flown on the Upper Atmosphere Research Satellite (UARS). These instruments measure the Doppler line profiles of the emission and absorption of certain atmospheric species (such as atomic oxygen) in the visible and infrared spectral region. The successful space flight of DE-FPI, HRDI, and CLAES on UARS demonstrated the extremely high spectral resolution and ruggedness of the etalon system for the remote sensing of earth and planetary atmospheres. Recently, an innovative FPI focal plane detection technique called the Circle-to-Line Interferometer Optical (CLIO) system was invented at the Space Physics Research Laboratory. The CLIO simplifies the FPI focal plane detection process by converting the circular rings or fringes into a linear pattern similar to that produced by a conventional spectrometer, while retaining the throughput advantage of the etalon interferometer. The combination of FPI and CLIO allows the development of more sensitive Fabry-Perot interferometers in the infrared for the remote sensing of the lower atmospheres of Earth and possibly other planets. The Multiorder Etalon Sounder (MOES), a combination of the rugged etalon and the CLIO, compares very favorably to other space-borne optical instruments in terms of performance versus complexity. The new instrument is expected to be rugged, compact, and very suitable for an operational temperature and moisture sounder. With this technique, the contamination of radiance measurements by emissions of other gases is also minimized. At the Space Physics Research Laboratory (SPRL), the MOES

  16. Topside sounders as mobile ionospheric heaters

    NASA Technical Reports Server (NTRS)

    Benson, R. F.

    2006-01-01

    There is evidence that satellite-borne RF sounders can act as mobile ionospheric heaters in addition to performing topside sounding. The main objective of topside sounding is to use sounder-generated electromagnetic (em) waves to obtain ionospheric topside vertical electron-density (N(sub e) profiles. These profiles are obtained from mathematical inversions of the frequency vs. delay-time ionospheric reflection traces. In addition to these em reflection traces, a number of narrowband intense signals are observed starting at zero delay times after the transmitted pulses. Some of these signals, termed plasma resonances, appear at characteristic frequencies of the ambient medium such as at the electron cyclotron frequency f(sub ce), the harmonics nf(sub ce), the electron plasma frequency f(sub pe) and the upper-hybrid frequency f(sub uh), where (f(sub uh))(exp 2) = (f(sub ce))(exp 2) + (f(sub pe))(exp 2) . These signals have been attributed to the oblique echoes of sounder-generated electrostatic (es) waves. These resonances provide accurate in situ f(sub pe) and f(sub ce) values which, in turn, lead to accurate N(sub e) and [B] values where B is the ambient magnetic field. Resonances are also observed between the nf(sub ce) harmonics both above and below f(sub uh). The former, known as the Qn plasma resonances, are mainly attributed to the matching of the wave group velocity of sounder-generated (Bernstein-mode) es waves to the satellite velocity. The frequency spectrum of these waves in the magnetosphere can be used to detect non-Maxwellian electron velocity-distributions. In addition, these resonances also exhibit components that appear to be the result of plasma emissions stimulated by the sounder pulses. The plasma resonances observed between the nf(sub ce) harmonics and below f(sub uh), known as the Dn plasma resonances, are entirely attributed to such sounder-stimulated plasma emissions. There are other sounder-stimulated plasma phenomena that also fall into

  17. Recent Advances in Laboratory Infrared Spectroscopy of Polycyclic Aromatic Hydrocarbons: PAHs in the Far Infrared

    NASA Technical Reports Server (NTRS)

    Mattioda, Andrew L.; Ricca, Alessandra; Tucker, Jonathan; Boersma, Christiaan; Bauschlicher, Charles, Jr.; Allamandola, Louis J.

    2010-01-01

    Over 25 years of observations and laboratory work have shown that the mid-IR spectra of a majority of astronomical sources are dominated by emission features near 3.3, 6.2, 7.7, and 11.2 microns, which originate in free polycyclic aromatic hydrocarbon (PAH) molecules. PAHs dominate the mid-IR emission from many galactic and extragalactic objects. As such, this material tracks a wide variety of astronomical processes, making this spectrum a powerful probe of the cosmos Apart from bands in the mid-IR, PAHs have bands spanning the Far-IR (FIR) and emission from these FIR features should be present in astronomical sources showing the Mid-IR PAH bands. However, with one exception, the FIR spectral characteristics are known only for a few neutral small PAHs trapped in salt pellets or oils at room temperature, data which is not relevant to astrophysics. Furthermore, since most emitting PAHs responsible for the mid-IR astronomical features are ionized, the absence of any experimental or theoretical PAH ion FIR spectra will make it impossible to correctly interpret the FIR data from these objects. In view of the upcoming Herschel space telescope mission and SOFIA's FIR airborne instrumentation, which will pioneer the FIR region, it is now urgent to obtain PAH FIR spectra. This talk will present an overview recent advances in the laboratory spectroscopy of PAHs, Highlighting the FIR spectroscopy along with some quantum calculations.

  18. Infrared spectroscopy study of electrochromic nanocrystalline tungsten oxide films made by reactive advanced gas deposition

    NASA Astrophysics Data System (ADS)

    Solis, J. L.; Hoel, A.; Lantto, V.; Granqvist, C. G.

    2001-03-01

    Nanocrystalline W oxide films were produced by advanced reactive gas deposition. The material consisted of ˜6 nm diameter tetragonal crystallites, as found from x-ray diffraction and electron microscopy. Optoelectrochemical measurements demonstrated electrochromism upon Li+ intercalation/deintercalation, and infrared absorption spectroscopy gave clear evidence for longitudinal and transversal optical modes being modified following the lithiation. Our data were consistent with ionic transport predominantly in disordered grain boundaries and intercrystalline regions and with electrochromism being associated with small polaron formation.

  19. GeoSTAR - A Microwave Sounder for Geostationary Satellites

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn; Wilson, William; Tanner, Alan; Gaier, Todd; Ruf, Chris; Piepmeier, Jeff

    2004-01-01

    GeoSTAR represents a new approach to microwave atmospheric sounding that is now under development. It has capabilities similar to sensors currently operating on low earth orbiting weather satellites but is intended for deployment in geostationary orbit - where it will complement future infrared sounders and enable all-weather temperature and humidity soundings and rain mapping. The required spatial resolution of 50 km or better dictates an aperture of 4 meters or more at a sounding frequency of 50 GHz, which is difficult to achieve with a real aperture system - this is the reason why it has until now not been possible to put a microwave sounder on a geostationary platform. GeoSTAR is instead based on a synthetic aperture imaging approach. Among the advantages of such a system are that there are no moving parts, and the size of the aperture is easily expandable to meet future needs. A ground based prototype of GeoSTAR is currently under development in an effort led by the Jet Propulsion Laboratory.

  20. Advances in mid-infrared detection and imaging: a key issues review.

    PubMed

    Razeghi, Manijeh; Nguyen, Binh-Minh

    2014-08-01

    It has been over 200 years since people recognized the presence of infrared radiation, and developed methods to capture this signal. However, current material systems and technologies for infrared detections have not met the increasing demand for high performance infrared detectors/cameras, with each system having intrinsic drawbacks. Type-II InAs/GaSb superlattice has been recently considered as a promising candidate for the next generation of infrared detection and imaging. Type-II superlattice is a man-made crystal structure, consisting of multiple quantum wells placed next to each other in a controlled way such that adjacent quantum wells can interact. The interaction between multiple quantum wells offers an additional degree of freedom in tailoring the material's properties. Another advantage of type-II superlattice is the experimental benefit of inheriting previous research on material synthesis and device fabrication of bulk semiconductors. It is the combination of these two unique strengths of type-II superlattice--novel physics and easy manipulation--that has enabled unprecedented progress in recent years. In this review, we will describe historical development, and current status of type-II InAs/GaSb superlattice for advanced detection and imaging in the mid-infrared regime (λ = 3-5 µm).

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

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

  2. Comparative study for the nondestructive testing of advanced ceramic materials by infrared thermography and holographic interferometry

    NASA Astrophysics Data System (ADS)

    Sfarra, S.; Ibarra-Castanedo, C.; Bendada, A.; Maldague, X.; Ambrosini, D.; Paoletti, D.

    2010-05-01

    Advanced ceramic materials are increasingly employed in varied and new applications where improved electrical, mechanical and/or thermal properties are sought. For instance, in a manner similar to carbon or glass fiber reinforced plastics, ceramic matrix composites (CMCs) are designed to improve the naturally brittle characteristics of monolithic ceramics thanks to the inclusion of fibers. Among the main interests for advanced ceramics are the increase in the operation temperature of components, the elimination of the use of cooling fluids, and weight savings. In this paper, the capabilities of infrared thermography and holographic interferometry are investigated and compared for the nondestructive assessment of advanced ceramic materials using three experimental specimens: (1) a monolithic green ceramic tile with fabricated defects, (2) a CMC specimen (from production reject) with a porous alumina matrix reinforced with glass fibers, and (3) a sandwich structure consisting on a carbon fiber honeycomb core with a ceramic plate bonded in one side.

  3. Mechanical Description of the Mars Climate Sounder Instrument

    NASA Technical Reports Server (NTRS)

    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.

  4. New application of the operational sounder HIRS in determining a climatology of sulphuric acid aerosol from the Pinatubo eruption

    SciTech Connect

    Baran, A.J.; Foot, J.S.

    1994-12-20

    The authors present satellite remote sounding measurements of sulphuric acid aerosols resulting from the Mt Pinatubo eruption. They show latitude distributions, column densities, and mass loadings as a function of time after the eruption. Measurements are interpreted from two different infrared channels in the sounder.

  5. LAWS (Laser Atmospheric Wind Sounder) earth observing system

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Wind profiles can be measured from space using current technology. These wind profiles are essential for answering many of the interdisciplinary scientific questions to be addressed by EOS, the Earth Observing System. This report provides guidance for the development of a spaceborne wind sounder, the Laser Atmospheric Wind Sounder (LAWS), discussing the current state of the technology and reviewing the scientific rationale for the instrument. Whether obtained globally from the EOS polar platform or in the tropics and subtropics from the Space Station, wind profiles from space will provide essential information for advancing the skill of numerical weather prediction, furthering knowledge of large-scale atmospheric circulation and climate dynamics, and improving understanding of the global biogeochemical and hydrologic cycles. The LAWS Instrument Panel recommends that it be given high priority for new instrument development because of the pressing scientific need and the availability of the necessary technology. LAWS is to measure wind profiles with an accuracy of a few meters per second and to sample at intervals of 100 km horizontally for layers km thick.

  6. Development of an ultrahigh-performance infrared detector platform for advanced spectroscopic sensing systems

    NASA Astrophysics Data System (ADS)

    Jain, Manish; Wicks, Gary; Marshall, Andrew; Craig, Adam; Golding, Terry; Hossain, Khalid; McEwan, Ken; Howle, Chris

    2014-05-01

    Laser-based stand-off sensing of threat agents (e.g. explosives, toxic industrial chemicals or chemical warfare agents), by detection of distinct infrared spectral absorption signature of these materials, has made significant advances recently. This is due in part to the availability of infrared and terahertz laser sources with significantly improved power and tunability. However, there is a pressing need for a versatile, high performance infrared sensor that can complement and enhance the recent advances achieved in laser technology. This work presents new, high performance infrared detectors based on III-V barrier diodes. Unipolar barrier diodes, such as the nBn, have been very successful in the MWIR using InAs(Sb)-based materials, and in the MWIR and LWIR using type-II InAsSb/InAs superlattice-based materials. This work addresses the extension of the barrier diode architecture into the SWIR region, using GaSb-based and InAs-based materials. The program has resulted in detectors with unmatched performance in the 2-3 μm spectral range. Temperature dependent characterization has shown dark currents to be diffusion limited and equal to, or within a factor of 5, of the Rule 07 expression for Auger-limited HgCdTe detectors. Furthermore, D* values are superior to those of existing detectors in the 2-3 μm band. Of particular significance to spectroscopic sensing systems is the ability to have near-background limited performance at operation temperatures compatible with robust and reliable solid state thermoelectric coolers.

  7. Lessons Learned from Previous Space-Borne Sounders as a Guide to Future Sounder Development

    NASA Technical Reports Server (NTRS)

    Benson, Robert F.; Deshpande, Manohar D.; Farrell,William M.; Fung, Shing F.; Osherovich, Vladimir A.; Pfaff, Rovert E.; Rowland, Douglas E.; Adrian, Mark L.

    2008-01-01

    Space-borne radio sounding is considered to be the gold standard for electron-density (N(sub e)) measurements compared to other techniques even under low-density conditions, such as N(sub e) < 1/cu cm, when other techniques are known to experience difficulties. These reliable measurements are not restricted to in-situ N(sub e) determinations since a spaceborne sounder can provide vertical N(sub e) profiles (N(sub e)(h)) from the spacecraft altitude to the altitude of maximum N(sub e). Near-conjunction studies involving the International Satellites for Ionospheric Studies (ISIS) satellites in the topside ionosphere and Dynamics Explorer 2 (DE 2) near the altitude of the F-region peak density have verified that, even at the greatest distance from the sounder, the ISIS-derived N(sub e)(h) profiles agree with the DE-2 Langmuir-probe measurements to within about 30% over a density range of more than two decades. Space-borne sounders can also provide N(sub e) profiles along the magnetic-field B, by inverting echoes that are ducted along field-aligned irregularities (FAI), and can provide information about the terrain beneath the satellite by examining surface reflections in the frequency range above the ionospheric penetration frequency. Many nations have launched rocket and satellite radio sounders in geospace over more than 4 decades and there have been sounders on space-probes and in orbit around other planets. Here we will summarize some of the lessons learned from these accomplishments by analyzing data from radio sounders on the Alouette and ISIS satellites and the OEDIPUS and other rockets in the terrestrial ionosphere, the IMAGE satellite in the terrestrial magnetosphere, the Ulysses space probe in Jupiter's 10 plasma torus and the MARSIS satellite in orbit around Mars. The emphasis will be on information deduced concerning (1) fundamental plasma processes and gradients in N, and B in the vicinity of the sounders from sounder-stimulated plasma resonances and

  8. Performance characteristics of advanced volume phase holographic gratings for operation in the near infrared

    NASA Astrophysics Data System (ADS)

    Arns, James A.

    2016-07-01

    Volume phase holographic (VPH) gratings are proven dispersing elements in astronomical spectrographs over the visible spectrum. VPH gratings have also been successfully deployed for use at cryogenic temperatures. Recent advances in production technology now permit the production of gratings for use in the near infrared up to 2450 nm at cryogenic conditions. This paper describes the requirements of VPH gratings for use in the H (wavelengths from 1500 nm to 1800 nm) and K (wavelengths from 1950 nm to 2450 nm) bands, gives the theoretical performances of diffraction efficiency for the production designs and presents the measured performances on the production gratings

  9. The AEDC aerospace chamber 7V: An advanced test capability for infrared surveillance and seeker sensors

    NASA Technical Reports Server (NTRS)

    Simpson, W. R.

    1994-01-01

    An advanced sensor test capability is now operational at the Air Force Arnold Engineering Development Center (AEDC) for calibration and performance characterization of infrared sensors. This facility, known as the 7V, is part of a broad range of test capabilities under development at AEDC to provide complete ground test support to the sensor community for large-aperture surveillance sensors and kinetic kill interceptors. The 7V is a state-of-the-art cryo/vacuum facility providing calibration and mission simulation against space backgrounds. Key features of the facility include high-fidelity scene simulation with precision track accuracy and in-situ target monitoring, diffraction limited optical system, NIST traceable broadband and spectral radiometric calibration, outstanding jitter control, environmental systems for 20 K, high-vacuum, low-background simulation, and an advanced data acquisition system.

  10. Earth Observing System (EOS)/Advanced Microwave Sounding Unit-A (AMSU-A): Calibration management plan

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is the Calibration Management Plan for the Earth Observing System/Advanced Microwave Sounding Unit-A (AMSU-A). The plan defines calibration requirements, calibration equipment, and calibration methods for the AMSU-A, a 15 channel passive microwave radiometer that will be used for measuring global atmospheric temperature profiles from the EOS polar orbiting observatory. The AMSU-A system will also provide data to verify and augment that of the Atmospheric Infrared Sounder.

  11. Study of advanced InSb arrays for SIRTF (Space Infrared Telescope Facility)

    NASA Technical Reports Server (NTRS)

    Hoffman, Alan; Feitt, Robert

    1989-01-01

    The Santa Barbara Research Center has completed a study leading to the development of advanced Indium Antimonide detector arrays for the Space Infrared Telescope Facility (SIRTF) Focal Plane Array Detector (FPAD) Subsystem of the Infrared Array Camera (IRAC) Band 1. The overall goal of the study was to perform design tradeoff studies, analysis and research to develop a Direct Readout Integrated Circuit to be hybridized to an advanced, high performance InSb detector array that would satisfy the technical requirements for Band 1 as specified in the IRAC Instrument Requirements Document (IRD), IRAC-202. The overall goal of the study was divided into both a near-term goal and a far-term goal. The near-term goal identifies current technology available that approaches, and in some cases meets the program technological goals as specified in IRAC-202. The far-term goal identifies technology development required to completely achieve SIRTF program goals. Analyses of potential detector materials indicates that InSb presently meets all Band 1 requirements and is considered to be the baseline approach due to technical maturity. The major issue with regard to photovoltaic detectors such as InSb and HgCdTe is to achieve a reduction in detector capacitance.

  12. Experimental characterization, evaluation, and diagnosis of advanced hybrid infrared focal plane array electro-optical performance

    NASA Astrophysics Data System (ADS)

    Lomheim, Terrence S.; Schumann, Lee W.; Kohn, Stanley E.

    1998-07-01

    High performance scanning time-delay-and-integration and staring hybrid focal plane devices with very large formats, small pixel sizes, formidable frame and line rates, on-chip digital programmability, and high dynamic ranges, are being developed for a myriad of defense, civil, and commercial applications that span the spectral range from shortwave infrared (SWIR) to longwave infrared (LWIR). An essential part in the development of such new advanced hybrid infrared focal planes is empirical validation of their electro-optical (EO) performance. Many high-reliability, high-performance applications demand stringent and near flawless EO performance over a wide variety of operating conditions and environments. Verification of focal plane performance compliance over this wide range of parametric conditions requires the development and use of accurate, flexible, and statistically complete test methods and associated equipment. In this paper we review typical focal plane requirements, the ensuing measurement requirements (quantity, accuracy, repeatability, etc.), test methodologies, test equipment requirements, electronics and computer-based data acquisition requirements, statistical data analysis and display requirements, and associated issues. We also discuss special test requirements for verifying the performance of panchromatic thermal and multispectral imaging focal planes where characterization of dynamic modulation transfer function (MTF), and point-image response and optical overload is generally required. We briefly overview focal plane radiation testing. We conclude with a discussion of the technical challenges of characterizing future advanced hybrid focal plane testing where it is anticipated that analog-to- digital conversion will be included directly on focal plane devices, thus creating the scenario of 'photons-in-to-bits- out' within the focal plane itself.

  13. Model-Based Infrared Metrology for Advanced Technology Nodes and 300 mm Wafer Processing

    NASA Astrophysics Data System (ADS)

    Rosenthal, Peter A.; Duran, Carlos; Tower, Josh; Mazurenko, Alex; Mantz, Ulrich; Weidner, Peter; Kasic, Alexander

    2005-09-01

    The use of infrared spectroscopy for production semiconductor process monitoring has evolved recently from primarily unpatterned, i.e. blanket test wafer measurements in a limited historical application space of blanket epitaxial, BPSG, and FSG layers to new applications involving patterned product wafer measurements, and new measurement capabilities. Over the last several years, the semiconductor industry has adopted a new set of materials associated with copper/low-k interconnects, and new structures incorporating exotic materials including silicon germanium, SOI substrates and high aspect ratio trenches. The new device architectures and more chemically sophisticated materials have raised new process control and metrology challenges that are not addressed by current measurement technology. To address the challenges we have developed a new infrared metrology tool designed for emerging semiconductor production processes, in a package compatible with modern production and R&D environments. The tool incorporates recent advances in reflectance instrumentation including highly accurate signal processing, optimized reflectometry optics, and model-based calibration and analysis algorithms. To meet the production requirements of the modern automated fab, the measurement hardware has been integrated with a fully automated 300 mm platform incorporating front opening unified pod (FOUP) interfaces, automated pattern recognition and high throughput ultra clean robotics. The tool employs a suite of automated dispersion-model analysis algorithms capable of extracting a variety of layer properties from measured spectra. The new tool provides excellent measurement precision, tool matching, and a platform for deploying many new production and development applications. In this paper we will explore the use of model based infrared analysis as a tool for characterizing novel bottle capacitor structures employed in high density dynamic random access memory (DRAM) chips. We will explore

  14. VAS demonstration: (VISSR Atmospheric Sounder) description

    NASA Technical Reports Server (NTRS)

    Montgomery, H. E.; Uccellini, L. W.

    1985-01-01

    The VAS Demonstration (VISSR Atmospheric Sounder) is a project designed to evaluate the VAS instrument as a remote sensor of the Earth's atmosphere and surface. This report describes the instrument and ground processing system, the instrument performance, the valiation as a temperature and moisture profiler compared with ground truth and other satellites, and assesses its performance as a valuable meteorological tool. The report also addresses the availability of data for scientific research.

  15. Rocket/Nimbus Sounder Comparison (RNSC)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The experimental results for radiance and temperature differences in the Wallops Island comparisons indicate that the differences between satellite and rocket systems are of the same order of magnitude as the differences among the various satellite and rocket sounders. The Arcasondes produced usable data to about 50 km, while the Datasondes require design modification. The SIRS and IRIS soundings provided usable data to 30 mb; extension of these soundings was also investigated.

  16. Radiation from sounder-accelerated electrons

    NASA Astrophysics Data System (ADS)

    James, H. G.

    2006-01-01

    Quasi-electrostatic Z-mode waves observed in the two-point OEDIPUS-C (OC) transmission experiment have been interpreted as incoherent radiation by sounder-accelerated electrons (SAE). A consistent interpretation of slow Z-mode waves created by SAE, based on wave and particle observations, has been built around the theory of incoherent radiation. The question therefore arises as to whether some transmitter-induced waves observed by monostatic sounder receivers in the same frequency domain, from the greater of the electron plasma and gyro frequencies to the upper-hybrid-resonance frequency, can also be explained as caused by SAE. Two candidate signal types routinely observed in the ISIS-II sounder receiver have been examined: (a) a diffuse resonance ’spike’ lasting a few milliseconds and (b) highly elongated pulses distributed smoothly throughout the entire frequency range observed when the ambient ionospheric plasma exhibits density irregularities. An examination of Z-mode wave phase and group velocities, combined with consideration of wave and spacecraft kinematics, indicate that the hypothesis of plane slow Z waves does not suffice. The particle detector located on the same payload as the OC transmitter measures SAE pulses lasting milliseconds. Consideration of the role of the transmitter payload body appears to be necessary to account for the retention around the payload of SAE at various pitch angles and energies up to about 100 eV.

  17. Retrievals with the Infrared Atmospheric Sounding Interferometer

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    The Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite was launched on October 19, 2006. The Joint Airborne IASI Validation Experiment (JAIVEx) was conducted during April 2007 mainly for validation of the IASI on the MetOp satellite. IASI possesses an ultra-spectral resolution of 0.25/cm and a spectral coverage from 645 to 2760/cm. Ultraspectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. An advanced retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. Preliminary retrievals of atmospheric soundings, surface properties, and cloud optical/microphysical properties with the IASI observations during the JAIVEx are obtained and presented. These retrievals are further inter-compared with those obtained from airborne FTS system, such as the NPOESS Airborne Sounder Testbed Interferometer (NAST-I), dedicated dropsondes, radiosondes, and ground based Raman Lidar. The capabilities of satellite ultra-spectral sounder such as the IASI are investigated.

  18. The Stratospheric Wind Ingrared Limb Sounder: Investigation of atmospheric dynamics and transport from Eos

    NASA Technical Reports Server (NTRS)

    Mccleese, D. J.

    1992-01-01

    The Stratospheric Wind Infrared Limb Sounder (SWIRLS) is one of the instruments in the atmospheric sounder package to be flown by NASA on the Earth Observing System (EOS) B platform in the late 1990's. SWIRLS is designed to measure the horizontal vector wind field, atmospheric temperature, and the abundances and distributions of ozone and nitrous oxide in the middle atmosphere. These measurements will constitute a dynamical climatology of the stratosphere covering time scales ranging from diurnal to interannual. In addition, the SWIRLS investigation will quantify the physical mechanisms responsible for the structure and variations of stratospheric circulation and temperature fields, including the transport of species, particularly ozone, heat and momentum. Existing data sets lack the combination of accuracy, global and temporal coverage, spatial resoultion and simultaneity required to distinguish unambiguosly between the roles of dynamical and chemical processes in determining the current distribution of ozone and its evolution in the future. The measurement objectives, measurement approach, and instrumentation of SWIRLS is described.

  19. Technology Development for a Hyperspectral Microwave Atmospheric Sounder (HyMAS)

    NASA Technical Reports Server (NTRS)

    Blackwell, W.; Galbraith, C.; Hilliard, L.; Racette, P.; Thompson, E.

    2014-01-01

    The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term hyperspectral microwave is used to indicate an all-weather sounding instrument that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earths atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions.

  20. Exploiting hyperspectral sounders for volcanic ash remote sensing

    NASA Astrophysics Data System (ADS)

    Western, Luke; Watson, Matthew; Francis, Peter

    2016-04-01

    Assumptions are made when retrieving properties of volcanic ash clouds using passive infrared satellite remote sensing. Assumptions in the retrieval method lead to larger uncertainties in the retrieved volcanic ash cloud properties. It is a general desire to reduce these uncertainties by removing some of the assumptions that must be made. Hyperspectral sounders provide the spectral capabilities to explore many of the physical parameters that describe volcanic ash clouds - the question is, which parameters is it possible to retrieve? We show that using the Infrared Atmospheric Sounding Interferometer (IASI) it is possible to retrieve the mass column loading and cloud top pressure of a volcanic ash cloud, together with the effective radius and spread of the ash particle size distribution, as well as the cloud top pressure of any underlying water cloud using an optimal estimation technique. We discuss the capabilities and shortcomings of the method. The consideration of an underlying water cloud is of importance for improving retrievals, and we place a particular focus on how well the particle size distribution can be described. More specifically, we investigate the viability of using either a lognormal or a gamma distribution to describe the distribution of ash particles, and we show that it is possible to retrieve information about the spread of a lognormal distribution of particles, whereas it is not for a gamma distribution. Some preliminary conclusions on the size distribution of volcanic ash are presented.

  1. Hyperspectral Microwave Atmospheric Sounder (HyMAS) Architecture and Design Accommodations

    NASA Technical Reports Server (NTRS)

    Hilliard, Lawrence; Racette, Paul; Blackwell, William; Galbraith, Christopher; Thompson, Erik

    2013-01-01

    The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term "hyperspectral microwave" is used to indicate an all-weather sounding that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earth s atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions. The simulations proposed for HyMAS 118/183-GHz system should yield surface precipitation rate and water path retrievals for small hail, soft hail, or snow pellets, snow, rainwater, etc. with accuracies comparable to those of the Advanced Technology Microwave Sounder. Further improvements in retrieval methodology (for example, polarization exploitation) are expected. The CoSMIR instrument is a packaging concept re-used on HyMAS to ease the integration features of the scanhead. The HyMAS scanhead will include an ultra-compact Intermediate Frequency Processor (IFP) module that is mounted inside the door to improve thermal management. The IFP is fabricated with materials made of Low-Temperature Co-fired Ceramic (LTCC) technology integrated with detectors, amplifiers, A/D conversion and data aggregation. The IFP will put out 52 channels of 16 bit data comprised of 4-9 channel data streams for temperature profiles and 2-8 channel streams for water vapor. With the limited volume of the existing CoSMIR scanhead and new HyMAS front end components, the HyMAS team at Goddard began preliminary layout work inside the new drum. Importing and re-using models of the shell, the scan head computer

  2. Hyperspectral Microwave Atmospheric Sounder (HyMAS) architecture and design accommodations

    NASA Astrophysics Data System (ADS)

    Hilliard, L.; Racette, P.; Blackwell, W.; Galbraith, C.; Thompson, E.

    The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term “ hyperspectral microwave” is used to indicate an all-weather sounding that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earth's atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions. The simulations proposed for HyMAS 118/183-GHz system should yield surface precipitation rate and water path retrievals for small hail, soft hail, or snow pellets, snow, rainwater, etc. with accuracies comparable to those of the Advanced Technology Microwave Sounder. Further improvements in retrieval methodology (for example, polarization exploitation) are expected. The CoSMIR instrument is a packaging concept re-used on HyMAS to ease the integration features of the scanhead. The HyMAS scanhead will include an ultra-compact Intermediate Frequency Processor (IFP) module that is mounted inside the door to improve thermal management. The IFP is fabricated with materials made of Low-Temperature Co-fired Ceramic (LTCC) technology integrated with detectors, amplifiers, A/D conversion and data aggregation. The IFP will put out 52 channels of 16 bit data comprised of 4 - 9 channel data streams for temperature profiles and 2-8 channel streams for water vapor. With the limited volume of the existing CoSMIR scanhead and new HyMAS front end components, the HyMAS team at Goddard began preliminary layout work inside the new drum. Importing and re-using models of the shell, the s- an head

  3. Recent Advancements in the Infrared Flow Visualization System for the NASA Ames Unitary Plan Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Garbeff, Theodore J., II; Baerny, Jennifer K.

    2017-01-01

    The following details recent efforts undertaken at the NASA Ames Unitary Plan wind tunnels to design and deploy an advanced, production-level infrared (IR) flow visualization data system. Highly sensitive IR cameras, coupled with in-line image processing, have enabled the visualization of wind tunnel model surface flow features as they develop in real-time. Boundary layer transition, shock impingement, junction flow, vortex dynamics, and buffet are routinely observed in both transonic and supersonic flow regimes all without the need of dedicated ramps in test section total temperature. Successful measurements have been performed on wing-body sting mounted test articles, semi-span floor mounted aircraft models, and sting mounted launch vehicle configurations. The unique requirements of imaging in production wind tunnel testing has led to advancements in the deployment of advanced IR cameras in a harsh test environment, robust data acquisition storage and workflow, real-time image processing algorithms, and evaluation of optimal surface treatments. The addition of a multi-camera IR flow visualization data system to the Ames UPWT has demonstrated itself to be a valuable analyses tool in the study of new and old aircraft/launch vehicle aerodynamics and has provided new insight for the evaluation of computational techniques.

  4. The Atmospheric Transmission Generation System for Satellite Infrared Sounders.

    DTIC Science & Technology

    1981-07-01

    THE PENTAGON WASHINGTON. DC 20361 GREAT LAKES WASHINGTON, DC 20350 DET. CHANUTE /STOP 62 COMMANDER CHANUTE AFB, IL 61868 CHIEF OF NAVAL RESEARCH... CHANUTE AFB, IL 61868 ACQUISITIONS SECTION COMMANDING OFFICER IRDB-D8?3 FLENUMOCEANCEN AFGWC/DAPL LIBRARY & INFO. SERV. DIV. MONTEREY, CA 93940 OFFUTT AFB

  5. High Resolution Infrared Radiation Sounder/mod 2 (HIRS/2)

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1979-01-01

    The HIRS/2 is provided for the TIROS-N series of operational meteorological satellites. The instrument features 20 spectral channels, including visible (.7 micron), shortwave (3.7 to 4.6 micron), and longwave (6.7 to 15 micron). Radiance data aids determination of vertical temperature profiles, water vapor, and ozone distribution. System performance and test results are described.

  6. Atmospheric Water Vapour Differential Absorption Measurements with an Infrared Sounder.

    DTIC Science & Technology

    1982-03-01

    such as amonia . As the differential absorption was only of the order of 2 dB for the above measurements (at 450 m range), the measurements were repeated...frequent(ref.7), and most seriously affect surface based radio frequency sensors and communications systems. Further development and refinement of the

  7. Lessons from 18 Years of Hyperspectral Infrared Sounder Data

    NASA Technical Reports Server (NTRS)

    Aumann, H. H.; Manning, E. M.; Strow, L. L.

    2013-01-01

    By the end of 2013 NASA and EUMETSAT will have accumulated more than 11 years of AIRS, 6 years of IASI and one year of CrIS data. All three instruments were nominally specified to support the NWC for short term weather forecasting with a five year lifetime, but continue to exceed the accuracy requirement needed for weather forecasting alone. This allows use of their data for a much broader range of applications, including the calibration of broad-band instruments in space and climate research. We illustrate calibration aspects with examples from AIRS, IASI and CrIS using spatially uniform clear conditions, simultaneous nadir overpasses and random nadir samples. The differences between AIRS, IASI and CrIS for the purpose of weather forecasting are small and we expect that the excellent forecast impact demonstrated by the combination of AIRS and IASI will be continued by the combination of CrIS and IASI. Clear data are useful for calibration, but contain no climate signal. The analysis of random nadir samples from AIRS and CrIS identifies larger biases for observation of extreme conditions, represented by 1% and 99%tile data than for non-extreme observations. This is relevant for climate analysis. Resolution of these differences require further work, since they can complicate the continuation of trends established by AIRS with CrIS data, at least for extrema. The unequaled stability of the AIRS data allows us to evaluate trends using random nadir sampled data. We see an increasing frequency in severe storms over land, a decreasing frequency over ocean. The 11 years of AIRS data are too short to tell if these trends are significant from a climate change viewpoint, or if they are parts of multi-decadal oscillations.

  8. View to the south with the Two Sounder Antennas on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View to the south with the Two Sounder Antennas on the left - Over-the-Horizon Backscatter Radar Network, Christmas Valley Radar Site Transmit Sector Four Sounder Antennas, On unnamed road west of Lost Forest Road, Christmas Valley, Lake County, OR

  9. Inter-Comparison of GOES-8 Imager and Sounder Skin Temperature Retrievals

    NASA Technical Reports Server (NTRS)

    Haines, Stephanie L.; Suggs, Ronnie J.; Jedlovec, Gary J.; Arnold, James E. (Technical Monitor)

    2001-01-01

    Skin temperature (ST) retrievals derived from geostationary satellite observations have both high temporal and spatial resolutions and are therefore useful for applications such as assimilation into mesoscale forecast models, nowcasting, and diagnostic studies. Our retrieval method uses a Physical Split Window technique requiring at least two channels within the longwave infrared window. On current GOES satellites, including GOES-11, there are two Imager channels within the required spectral interval. However, beginning with the GOES-M satellite the 12-um channel will be removed, leaving only one longwave channel. The Sounder instrument will continue to have three channels within the longwave window, and therefore ST retrievals will be derived from Sounder measurements. This research compares retrievals from the two instruments and evaluates the effects of the spatial resolution and sensor calibration differences on the retrievals. Both Imager and Sounder retrievals are compared to ground-truth data to evaluate the overall accuracy of the technique. An analysis of GOES-8 and GOES-11 intercomparisons is also presented.

  10. Radar sounder performances for ESA JUICE mission

    NASA Astrophysics Data System (ADS)

    Berquin, Y. P.; Kofman, W. W.; Heggy, E.; Hérique, A.

    2012-12-01

    The Jupiter Icy moons Explorer (JUICE) is the first Large-class mission chosen as part of ESA's Cosmic Vision 2015-2025 program. The mission will study Jovian icy moons Ganymede and Europa as potential habitats for life, addressing two key themes of Cosmic Vision namely the conditions for planet formation and the emergence of life, and the Solar System interactions. The radar sounder instrument on this mission will have great potential to address specific science questions such as the presence of subsurface liquid water and ice shell geophysical structures. One major constraint for radar sounding is the roughness of the planetary surface. The work presented will focus on the characterization of Ganymede's surface topography to better understand its surface properties from a radar point of view. These results should help to put constraints on the design of JUICE's radar sounder. We use topographic data derived from the Voyager and Galileo missions images to try to characterize the surface structure and to quantify its geometry (in terms of slopes and RMS heights mainly). This study will help us evaluating the radar budget in a statistical approach. In addition, deterministic simulations of surface radar echoes conducted on synthetic surfaces -extrapolated from Digital Elevation Models- will be presented to better assess radar sounding performances.

  11. Topside sounder observations of equatorial bubbles

    NASA Technical Reports Server (NTRS)

    Dyson, P. L.; Benson, R. F.

    1978-01-01

    Large scale regions of depleted equatorial ionospheric plasma, called equatorial bubbles, are investigated using topside sounder data. The sounder's unique remote measuring capability enables the magnetic field-aligned nature of the bubbles to be investigated. A search of all available Alouette 2 and ISIS 1 ionograms during nighttime perigee passes near the magnetic equator has revealed a variety of echo signatures associated with bubbles. In addition to a sudden drop in electron density, these signatures usually include in situ spread F and ducted traces. The ducted traces have been used to determine the electron density distribution and to infer changes in ion composition along the magnetic field line within the duct associated with the bubble. In some cases it can be determined that the bubble is asymmetric with respect to the magnetic equator. Even though such features require 3 dimensional models for their explanation, the great field-aligned extent of the bubbles (relative to their cross section) suggests that current theories, which ignore variations along the magnetic field, are still applicable.

  12. The GEISA system in 1996: towards an operational tool for the second generation vertical sounders radiance simulation.

    NASA Astrophysics Data System (ADS)

    Jacquinet-Husson, N.; Scott, N. A.; Chedin, A.; Bonnet, B.; Barbe, A.; Tyuterev, V. G.; Champion, J. P.; Winnewisser, M.; Brown, L. R.; Gamache, R.; Golovko, V. F.; Chursin, A. A.

    1998-05-01

    Since their creation, in 1974, the GEISA (Gestion et Etude des Informations Spectroscopiques Atmospheriques: Management and Study of Atmospheric Spectroscopic Information) database system (more than 730,000 entries between 0 and 22,656 cm-1, corresponding to 40 molecules and 86 isotopic species, in its 1992 edition) and the associated software have been widely used for forward atmospheric radiative transfer modelling, with the maximum reliability, tractability and efficiency. For the upcoming high spectral resolution sounders like IASI (Infrared Atmospheric Sounding Interferometer) and AIRS (Atmospheric InfraRed Sounder), more complete and accurate laboratory measurements of spectroscopic parameters, presently included in the databases, are required, and more sophisticated theoretical radiative transfer modelling should be developed. Consequently, it is intended to elaborate the GEISA database as an interactive tool, named GEISA/IASI, designed for providing spectroscopic information tailored to the IASI sounding radiative transfer modelling.

  13. Cloud properties and bulk microphysical properties of semi-transparent cirrus from IR Sounders

    NASA Astrophysics Data System (ADS)

    Stubenrauch, Claudia; Feofilov, Artem; Armante, Raymond; Guignard, Anthony

    2013-04-01

    Satellite observations provide a continuous survey of the atmosphere over the whole globe. IR sounders have been observing our planet since 1979. The spectral resolution has improved from TIROS-N Operational Vertical Sounders (TOVS) to the Atmospheric InfraRed Sounder (AIRS), and to the InfraRed Atmospheric Sounding Interferometer (IASI); resolution within the CO2 absorption band makes these passive sounders most sensitive to semi-transparent cirrus (about 30% of all clouds), day and night. The LMD cloud property retrieval method developed for TOVS, has been adapted to the second generation of IR sounders like AIRS and, recently, IASI. It is based on a weighted χ2 method using different channels within the 15 micron CO2 absorption band. Once the cloud physical properties (cloud pressure and IR emissivity) are retrieved, cirrus bulk microphysical properties (De and IWP) are determined from spectral emissivity differences between 8 and 12 μm. The emissivities are determined using the retrieved cloud pressure and are then compared to those simulated by the radiative transfer model. For IASI, we use the latest version of the radiative transfer model 4A (http://4aop.noveltis.com), which has been coupled with the DISORT algorithm to take into account multiple scattering of ice crystals. The code incorporates single scattering properties of column-like or aggregate-like ice crystals provided by MetOffice (Baran et al. (2001); Baran and Francis (2004)). The synergy of AIRS and two active instruments of the A-Train (lidar and radar of the CALIPSO and CloudSat missions), which provide accurate information on vertical cloud structure, allowed the evaluation of cloud properties retrieved by the weighted χ2 method. We present first results for cloud properties obtained with IASI/ Metop-A and compare them with those of AIRS and other cloud climatologies having participated in the GEWEX cloud assessment. The combination of IASI observations at 9:30 AM and 9:30 PM complement

  14. Advances in the characterization of InAs/GaSb superlattice infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Wörl, A.; Daumer, V.; Hugger, T.; Kohn, N.; Luppold, W.; Müller, R.; Niemasz, J.; Rehm, R.; Rutz, F.; Schmidt, J.; Schmitz, J.; Stadelmann, T.; Wauro, M.

    2016-10-01

    This paper reports on advances in the electro-optical characterization of InAs/GaSb short-period superlattice infrared photodetectors with cut-off wavelengths in the mid-wavelength and long-wavelength infrared ranges. To facilitate in-line monitoring of the electro-optical device performance at different processing stages we have integrated a semi-automated cryogenic wafer prober in our process line. The prober is configured for measuring current-voltage characteristics of individual photodiodes at 77 K. We employ it to compile a spatial map of the dark current density of a superlattice sample with a cut-off wavelength around 5 μm patterned into a regular array of 1760 quadratic mesa diodes with a pitch of 370 μm and side lengths varying from 60 to 350 μm. The different perimeter-to-area ratios make it possible to separate bulk current from sidewall current contributions. We find a sidewall contribution to the dark current of 1.2×10-11 A/cm and a corrected bulk dark current density of 1.1×10-7 A/cm2, both at 200 mV reverse bias voltage. An automated data analysis framework can extract bulk and sidewall current contributions for various subsets of the test device grid. With a suitable periodic arrangement of test diode sizes, the spatial distribution of the individual contributions can thus be investigated. We found a relatively homogeneous distribution of both bulk dark current density and sidewall current contribution across the sample. With the help of an improved capacitance-voltage measurement setup developed to complement this technique a residual carrier concentration of 1.3×1015 cm-3 is obtained. The work is motivated by research into high performance superlattice array sensors with demanding processing requirements. A novel long-wavelength infrared imager based on a heterojunction concept is presented as an example for this work. It achieves a noise equivalent temperature difference below 30 mK for realistic operating conditions.

  15. Measurements of stratospheric NO2 by the improved stratospheric and mesospheric sounder

    NASA Astrophysics Data System (ADS)

    Reburn, W. J.; Remedios, J. J.; Ballard, J.; Lawrence, B. N.; Taylor, F. W.

    1993-06-01

    Limb sounding measurements of infra-red emission at 6.2 μm from the Earth's atmosphere have been made by the Improved Stratospheric and Mesospheric Sounder (ISAMS). This provides a pressure modulated gas-correlation signal and a wideband signal from which NO2 and aerosol extinction at 6.2 μm are jointly retrieved between 100 mb and 0.3 mb. The retrieval scheme is discussed with reference to NO2 and a qualitative comparison made with LIMS data. The ISAMS Northern hemisphere NO2 data for January 9th 1992 are then examined and the importance of dynamical factors highlighted.

  16. Far-infrared pedestrian detection for advanced driver assistance systems using scene context

    NASA Astrophysics Data System (ADS)

    Wang, Guohua; Liu, Qiong; Wu, Qingyao

    2016-04-01

    Pedestrian detection is one of the most critical but challenging components in advanced driver assistance systems. Far-infrared (FIR) images are well-suited for pedestrian detection even in a dark environment. However, most current detection approaches just focus on pedestrian patterns themselves, where robust and real-time detection cannot be well achieved. We propose a fast FIR pedestrian detection approach, called MAP-HOGLBP-T, to explicitly exploit the scene context for the driver assistance system. In MAP-HOGLBP-T, three algorithms are developed to exploit the scene contextual information from roads, vehicles, and background objects of high homogeneity, and we employ the Bayesian approach to build a classifier learner which respects the scene contextual information. We also develop a multiframe approval scheme to enhance the detection performance based on spatiotemporal continuity of pedestrians. Our empirical study on real-world datasets has demonstrated the efficiency and effectiveness of the proposed method. The performance is shown to be better than that of state-of-the-art low-level feature-based approaches.

  17. Advancement of an Infra-Red Technique for Whole-Field Concentration Measurements in Fluidized Beds

    PubMed Central

    Medrano, Jose A.; de Nooijer, Niek C. A.; Gallucci, Fausto; van Sint Annaland, Martin

    2016-01-01

    For a better understanding and description of the mass transport phenomena in dense multiphase gas-solids systems such as fluidized bed reactors, detailed and quantitative experimental data on the concentration profiles is required, which demands advanced non-invasive concentration monitoring techniques with a high spatial and temporal resolution. A novel technique based on the selective detection of a gas component in a gas mixture using infra-red properties has been further developed. The first stage development was carried out using a very small sapphire reactor and CO2 as tracer gas. Although the measuring principle was demonstrated, the real application was hindered by the small reactor dimensions related to the high costs and difficult handling of large sapphire plates. In this study, a new system has been developed, that allows working at much larger scales and yet with higher resolution. In the new system, propane is used as tracer gas and quartz as reactor material. In this study, a thorough optimization and calibration of the technique is presented which is subsequently applied for whole-field measurements with high temporal resolution. The developed technique allows the use of a relatively inexpensive configuration for the measurement of detailed concentration fields and can be applied to a large variety of important chemical engineering topics. PMID:26927127

  18. Quantum Well and Quantum Dot Modeling for Advanced Infrared Detectors and Focal Plane Arrays

    NASA Technical Reports Server (NTRS)

    Ting, David; Gunapala, S. D.; Bandara, S. V.; Hill, C. J.

    2006-01-01

    This viewgraph presentation reviews the modeling of Quantum Well Infrared Detectors (QWIP) and Quantum Dot Infrared Detectors (QDIP) in the development of Focal Plane Arrays (FPA). The QWIP Detector being developed is a dual band detector. It is capable of running on two bands Long-Wave Infrared (LWIR) and Medium Wavelength Infrared (MWIR). The same large-format dual-band FPA technology can be applied to Quantum Dot Infrared Photodetector (QDIP) with no modification, once QDIP exceeds QWIP in single device performance. Details of the devices are reviewed.

  19. RAWS: The spaceborne radar wind sounder

    NASA Technical Reports Server (NTRS)

    Moore, Richard K.

    1991-01-01

    The concept of the Radar Wind Sounder (RAWS) is discussed. The goals of the RAWS is to estimate the following three qualities: the echo power, to determine rain rate and surface wind velocity; the mean Doppler frequency, to determine the wind velocity in hydrometers; and the spread of the Doppler frequency, to determine the turbulent spread of the wind velocity. Researchers made significant progress during the first year. The feasibility of the concept seems certain. Studies indicate that a reasonably sized system can measure in the presence of ice clouds and dense water clouds. No sensitivity problems exist in rainy environments. More research is needed on the application of the radar to the measurement of rain rates and winds at the sea surface.

  20. RAWS: The spaceborne radar wind sounder

    NASA Astrophysics Data System (ADS)

    Moore, Richard K.

    1991-09-01

    The concept of the Radar Wind Sounder (RAWS) is discussed. The goals of the RAWS is to estimate the following three qualities: the echo power, to determine rain rate and surface wind velocity; the mean Doppler frequency, to determine the wind velocity in hydrometers; and the spread of the Doppler frequency, to determine the turbulent spread of the wind velocity. Researchers made significant progress during the first year. The feasibility of the concept seems certain. Studies indicate that a reasonably sized system can measure in the presence of ice clouds and dense water clouds. No sensitivity problems exist in rainy environments. More research is needed on the application of the radar to the measurement of rain rates and winds at the sea surface.

  1. EOS Laser Atmosphere Wind Sounder (LAWS) investigation

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In this final report, the set of tasks that evolved from the Laser Atmosphere Wind Sounder (LAWS) Science Team are reviewed, the major accomplishments are summarized, and a complete set of resulting references provided. The tasks included preparation of a plan for the LAWS Algorithm Development and Evolution Laboratory (LADEL); participation in the preparation of a joint CNES/NASA proposal to build a space-based DWL; involvement in the Global Backscatter Experiments (GLOBE); evaluation of several DWL concepts including 'Quick-LAWS', SPNDL and several direct detection technologies; and an extensive series of system trade studies and Observing System Simulation Experiments (OSSE's). In this report, some of the key accomplishments are briefly summarized with reference to interim reports, special reports, conference/workshop presentations, and publications.

  2. Assessment of intercalibration methods for satellite microwave humidity sounders

    NASA Astrophysics Data System (ADS)

    John, Viju O.; Allan, Richard P.; Bell, William; Buehler, Stefan A.; Kottayil, Ajil

    2013-05-01

    Three methods for intercalibrating humidity sounding channels are compared to assess their merits and demerits. The methods use the following: (1) natural targets (Antarctica and tropical oceans), (2) zonal average brightness temperatures, and (3) simultaneous nadir overpasses (SNOs). Advanced Microwave Sounding Unit-B instruments onboard the polar-orbiting NOAA 15 and NOAA 16 satellites are used as examples. Antarctica is shown to be useful for identifying some of the instrument problems but less promising for intercalibrating humidity sounders due to the large diurnal variations there. Owing to smaller diurnal cycles over tropical oceans, these are found to be a good target for estimating intersatellite biases. Estimated biases are more resistant to diurnal differences when data from ascending and descending passes are combined. Biases estimated from zonal-averaged brightness temperatures show large seasonal and latitude dependence which could have resulted from diurnal cycle aliasing and scene-radiance dependence of the biases. This method may not be the best for channels with significant surface contributions. We have also tested the impact of clouds on the estimated biases and found that it is not significant, at least for tropical ocean estimates. Biases estimated from SNOs are the least influenced by diurnal cycle aliasing and cloud impacts. However, SNOs cover only relatively small part of the dynamic range of observed brightness temperatures.

  3. A Submillimeter Sounder for Measuring Martian Winds and Water

    NASA Astrophysics Data System (ADS)

    Tamppari, L. K.; Livesey, N. J.; Read, W. G.

    2016-10-01

    We review the scientific need for global vertically resolved observations of martian atmospheric winds, and show that a submillimeter limb sounder can provide such measurements, along with measurements of water vapor and other trace gases.

  4. New advances in the use of infrared absorption spectroscopy for the characterization of heterogeneous catalytic reactions.

    PubMed

    Zaera, Francisco

    2014-11-21

    Infrared absorption spectroscopy has proven to be one of the most powerful spectroscopic techniques available for the characterization of catalytic systems. Although the history of IR absorption spectroscopy in catalysis is long, the technique continues to provide key fundamental information about a variety of catalysts and catalytic reactions, and to also offer novel options for the acquisition of new information on both reaction mechanisms and the nature of the solids used as catalysts. In this review, an overview is provided of the main contributions that have been derived from IR absorption spectroscopy studies of catalytic systems, and a discussion is included on new trends and new potential directions of research involving IR in catalysis. We start by briefly describing the power of Fourier-transform IR (FTIR) instruments and the main experimental IR setups available, namely, transmission (TIR), diffuse reflectance (DRIFTS), attenuated total reflection (ATR-IR), and reflection-absorption (RAIRS), for advancing research in catalysis. We then discuss the different environments under which IR characterization of catalysts is carried out, including in situ and operando studies of typical catalytic processes in gas-phase, research with model catalysts in ultrahigh vacuum (UHV) and so-called high-pressure cell instruments, and work involving liquid/solid interfaces. A presentation of the type of information extracted from IR data follows in terms of the identification of adsorbed intermediates, the characterization of the surfaces of the catalysts themselves, the quantitation of IR intensities to extract surface coverages, and the use of probe molecules to identify and titrate specific catalytic sites. Finally, the different options for carrying out kinetic studies with temporal resolution such as rapid-scan FTIR, step-scan FTIR, and the use of tunable lasers or synchrotron sources, and to obtain spatially resolved spectra, by sample rastering or by 2D imaging, are

  5. Measurements of stratospheric volcanic aerosol optical depth from NOAA TIROS Observational Vertical Sounder (TOVS) observations

    NASA Astrophysics Data System (ADS)

    Pierangelo, CléMence; ChéDin, Alain; Chazette, Patrick

    2004-02-01

    We show that the infrared optical depth of stratospheric volcanic aerosols produced by the eruption of Mount Pinatubo in June 1991 may be retrieved from the observations of the High-Resolution Infrared Radiation Sounder (HIRS-2) on board the polar meteorological satellites of the National Oceanic and Atmospheric Administration (NOAA). Evolution of the concentration in time and in space, in particular the migration of the aerosols from the tropics to the Northern and Southern Hemispheres, is found to be consistent with our knowledge of the consequences of this eruption. The method relies on the analysis of the differences between the satellite observations and simulations from an aerosol-free radiative transfer model using collocated radiosonde data as the prime input. Thus aerosol optical depths are retrieved directly without making assumptions about the aerosol size distribution or absorption coefficient. The aerosol optical depths reached a maximum in August 1991 in the tropical zone (0.055 at 8.3 μm, 0.03 at 4.0 μm, and 0.02 at 11.1 μm). The peak occurred in November 1991 in the southern midlatitudes and in March/April 1992 in the northern midlatitudes. A reanalysis of the almost 25 year archive of NOAA TIROS-N Operational Vertical Sounder (TOVS) observations holds considerable promise for improved knowledge of the atmosphere loading in volcanic aerosols.

  6. Planetary protection for Europa radar sounder antenna

    NASA Astrophysics Data System (ADS)

    Aaron, Kim M.; Moussessian, Alina; Newlin, Laura E.; Willis, Paul B.; Chen, Fei; Harcke, Leif J.; Chapin, Elaine; Jun, Insoo; Gim, Yonggyu; McEachen, Michael; Allen, Scotty; Kirchner, Donald; Blankenship, Donald

    2016-05-01

    The potential for habitability puts stringent requirements on planetary protection for a mission to Europa. A long-wavelength radar sounder with a large antenna is one of the proposed instruments for a future Europa mission. The size and construction of radar sounding antennas make the usual methods of meeting planetary protection requirements challenging. This paper discusses a viable planetary protection scheme for an antenna optimized for Europa radar sounding. The preferred methodology for this antenna is exposure to 100 kGy (10 Mrad) in water of gamma radiation using a Cobalt-60 source for both bulk and surface sterilization and exposure to vapor hydrogen peroxide for surface treatment for possible recontamination due to subsequent handling. For the boom-supported antenna design, selected tests were performed to confirm the suitability of these treatment methods. A portion of a coilable boom residual from an earlier mission was irradiated and its deployment repeatability confirmed with no degradation. Elasticity was measured of several fiberglass samples using a four-point bending test to confirm that there was no degradation due to radiation exposure. Vapor hydrogen peroxide treatment was applied to the silver-coated braid used as the antenna radiating element as it was the material most likely to be susceptible to oxidative attack under the treatment conditions. There was no discernable effect. These tests confirm that the radar sounding antenna for a Europa mission should be able tolerate the proposed sterilization methods.

  7. Lithography with infrared illumination alignment for advanced BiCMOS backside processing

    NASA Astrophysics Data System (ADS)

    Kulse, P.; Schulz, K.; Behrendt, U.; Wietstruck, M.; Kaynak, M.; Marschmeyer, S.; Tillack, B.

    2014-10-01

    Driven by new applications such as BiCMOS embedded RF-MEMS, high-Q passives, Si-based microfluidics for bio sensing and InP-Si BiCMOS heterointegration [1-4], accurate alignment between back and front side is highly desired. In this paper, we present an advanced back to front side alignment technique and implementation of it into the back side processing module of IHP's 0.25/0.13 μm high performance SiGe:C BiCMOS technology. Using the Nikon i-line Stepper NSR-SF150, a new infrared alignment system has been introduced. The developed technique enables a high resolution and accurate lithography on the back side of the BiCMOS-processed Si wafers for additional backside processing, such as backside routing metallization. In comparison to previous work [5] with overlay values of 500 nm and the requirement of two-step lithography, the new approach provides significant improvement in the overlay accuracy with overlay values of 200 nm and a significant increase of the fabrication throughput by eliminating the need of the two-step lithography. The new non-contact alignment procedure allows a direct back to front side alignment using any front side alignment mark (Fig. 2), which generated a signal by reflecting the IR light beam. Followed by a measurement of the misalignment between both front to back side overlay marks (Fig. 3) using EVG®NT40 automated measurement system, a final lithography process with wafer interfield corrections is applied to obtain a minimum overlay of 200 nm. For the specific application of deep Si etching using Bosch process, the etch profile angle deviation across the wafer (tilting) has to be considered as well. From experimental data, an etch profile angle deviation of 8 μm across the wafer has been measured (Fig. 7). The overlay error caused by tilting was corrected by optimization and adjustment of the stepper offset parameters. All measurements of back to front side misalignment were performed with the EVG®40NT automated measurement system

  8. Revolutionary visible and infrared sensor detectors for the most advanced astronomical AO systems

    NASA Astrophysics Data System (ADS)

    Feautrier, Philippe; Gach, Jean-Luc; Guieu, Sylvain; Downing, Mark; Jorden, Paul; Rothman, Johan; de Borniol, Eric D.; Balard, Philippe; Stadler, Eric; Guillaume, Christian; Boutolleau, David; Coussement, Jérome; Kolb, Johann; Hubin, Norbert; Derelle, Sophie; Robert, Clélia; Tanchon, Julien; Trollier, Thierry; Ravex, Alain; Zins, Gérard; Kern, Pierre; Moulin, Thibaut; Rochat, Sylvain; Delpoulbé, Alain; Lebouqun, Jean-Baptiste

    2014-07-01

    We report in this paper decisive advance on the detector development for the astronomical applications that require very fast operation. Since the CCD220 and OCAM2 major success, new detector developments started in Europe either for visible and IR wavelengths. Funded by ESO and the FP7 Opticon European network, the NGSD CMOS device is fully dedicated to Natural and Laser Guide Star AO for the E-ELT with strong ESO involvement. The NGSD will be a 880x840 pixels CMOS detector with a readout noise of 3 e (goal 1e) at 700 Hz frame rate and providing digital outputs. A camera development, based on this CMOS device and also funded by the Opticon European network, is ongoing. Another major AO wavefront sensing detector development concerns IR detectors based on Avalanche Photodiode (e- APD) arrays within the RAPID project. Developed by the SOFRADIR and CEA/LETI manufacturers, the latter offers a 320x255 8 outputs 30 microns IR array, sensitive from 0.4 to 3 microns, with less than 2 e readout noise at 1600 fps. A rectangular window can also be programmed to speed up even more the frame rate when the full frame readout is not required. The high QE response, in the range of 70%, is almost flat over this wavelength range. Advanced packaging with miniature cryostat using pulse tube cryocoolers was developed in the frame of this programme in order to allow use on this detector in any type of environment. The characterization results of this device are presented here. Readout noise as low as 1.7 e at 1600 fps has been measured with a 3 microns wavelength cut-off chip and a multiplication gain of 14 obtained with a limited photodiode polarization of 8V. This device also exhibits excellent linearity, lower than 1%. The pulse tube cooling allows smart and easy cooling down to 55 K. Vibrations investigations using centroiding and FFT measurements were performed proving that the miniature pulse tube does not induce measurable vibrations to the optical bench, allowing use of this

  9. Upper tropospheric cloud systems derived from IR sounders: properties of cirrus anvils in the tropics

    NASA Astrophysics Data System (ADS)

    Protopapadaki, Sofia E.; Stubenrauch, Claudia J.; Feofilov, Artem G.

    2017-03-01

    Representing about 30 % of the Earth's total cloud cover, upper tropospheric clouds play a crucial role in the climate system by modulating the Earth's energy budget and heat transport. When originating from convection, they often form organized systems. The high spectral resolution of the Atmospheric Infrared Sounder (AIRS) allows reliable cirrus identification, both from day and nighttime observations. Tropical upper tropospheric cloud systems have been analyzed by using a spatial composite technique on the retrieved cloud pressure of AIRS data. Cloud emissivity is used to distinguish convective core, cirrus and thin cirrus anvil within these systems. A comparison with simultaneous precipitation data from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) shows that, for tropical upper tropospheric clouds, a cloud emissivity close to 1 is strongly linked to a high rain rate, leading to a proxy to identify convective cores. Combining AIRS cloud data with this cloud system approach, using physical variables, provides a new opportunity to relate the properties of the anvils, including also the thinner cirrus, to the convective cores. It also distinguishes convective cloud systems from isolated cirrus systems. Deep convective cloud systems, covering 15 % of the tropics, are further distinguished into single-core and multi-core systems. Though AIRS samples the tropics only twice per day, the evolution of longer-living convective systems can be still statistically captured, and we were able to select relatively mature single-core convective systems by using the fraction of convective core area within the cloud systems as a proxy for maturity. For these systems, we have demonstrated that the physical properties of the anvils are related to convective depth, indicated by the minimum retrieved cloud temperature within the convective core. Our analyses show that the size of the systems does in general increase with convective depth, though for

  10. Tropospheric water vapor retrieval from a nadir THz/FIR sounder

    NASA Astrophysics Data System (ADS)

    Baron, Philippe; Mendrok, Jana; Dupuy, Eric; Kasai, Yasuko

    2008-12-01

    This work presents clear-sky simulations to study water vapor (H2O) retrieval from a nadir sounder operating in the TeraHertz (THz) and Far-Infrared (FIR) spectral domains (100-500 cm-1). The THz/FIR retrieval is compared with retrieval from the mid-InfraRed (IR) 7μm H2O band (1200-2000 cm-1). The THz/FIR observations are more sensitive in the upper troposphere and lower stratosphere than the IR measurements. On the other hand, the IR sounder has better performance in the lower troposphere. The retrieval error due to uncertainties on the temperature profile are of the same order of magnitude in the THz/FIR and IR bands. No significant retrieval errors from contaminating species have been found. The calculations for several atmospheric scenarios show that retrieval performances are not only dependent on the H2O abundance but also on the temperature gradient. Hence, sensitivity in the UT/LS layer, with a low temperature gradient, is poor. The combination of FIR and IR merges the advantages of both bands, and allows to slightly decorrelate temperature and H2O VMR.

  11. Lossless compression of 3D hyperspectral sounder data using the wavelet and Burrows-Wheeler transforms

    NASA Astrophysics Data System (ADS)

    Wei, Shih-Chieh; Huang, Bormin

    2004-10-01

    Hyperspectral sounder data is used for retrieval of useful geophysical parameters which promise better weather prediction. It features two characteristics. First it is huge in size with 2D spatial coverage and high spectral resolution in the infrared region. Second it allows low tolerance of noise and error in retrieving the geophysical parameters where a mathematically ill-posed problem is involved. Therefore compression is better to be lossless or near lossless for data transfer and archive. Meanwhile medical data from X-ray computerized tomography (CT) or magnetic resonance imaging (MRI) techniques also possesses similar characteristics. It provides motivation to apply lossless compression schemes for medical data to the hyperspectral sounder data. In this paper, we explore the use of a wavelet-based lossless data compression scheme for the 3D hyperspectral data which uses in sequence a forward difference scheme, an integer wavelet transform, a Burrows-Wheeler transform and an arithmetic coder. Compared to previous work, our approach is shown to outperform the CALIC and 3D EZW schemes.

  12. View to the eastnortheast of the Sounder Antenna OvertheHorizon ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View to the east-northeast of the Sounder Antenna - Over-the-Horizon Backscatter Radar Network, Christmas Valley Radar Site Transmit Sector Five Sounder Antennas, On unnamed road west of Lost Forest Road, Christmas Valley, Lake County, OR

  13. View to the northeast of the Sounder Antenna OvertheHorizon ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View to the northeast of the Sounder Antenna - Over-the-Horizon Backscatter Radar Network, Christmas Valley Radar Site Transmit Sector Five Sounder Antennas, On unnamed road west of Lost Forest Road, Christmas Valley, Lake County, OR

  14. Advances in Data Processing for Open-path Fourier Transform Infrared Spectrometry of Greenhouse Gases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The automated quantification of three greenhouse gases, ammonia, methane and nitrous oxide, in the vicinity of a large dairy farm by open-path Fourier transform infrared (OP/FT-IR) spectrometry at intervals of 5 minutes is demonstrated. Spectral pretreatment, including the detection and correction ...

  15. Recent advances in the use of non-destructive near infrared spectroscopy on intact olive fruits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this review is to illustrate the state of the art in the use of non-destructive near infrared (NIR) spectroscopy for quality evaluation of intact fruit in the olive industry. First, the most recent studies regarding the application of non-destructive NIR spectroscopy methods to asse...

  16. IRLooK: an advanced mobile infrared signature measurement, data reduction, and analysis system

    NASA Astrophysics Data System (ADS)

    Cukur, Tamer; Altug, Yelda; Uzunoglu, Cihan; Kilic, Kayhan; Emir, Erdem

    2007-04-01

    Infrared signature measurement capability has a key role in the electronic warfare (EW) self protection systems' development activities. In this article, the IRLooK System and its capabilities will be introduced. IRLooK is a truly innovative mobile infrared signature measurement system with all its design, manufacturing and integration accomplished by an engineering philosophy peculiar to ASELSAN. IRLooK measures the infrared signatures of military and civil platforms such as fixed/rotary wing aircrafts, tracked/wheeled vehicles and navy vessels. IRLooK has the capabilities of data acquisition, pre-processing, post-processing, analysis, storing and archiving over shortwave, mid-wave and long wave infrared spectrum by means of its high resolution radiometric sensors and highly sophisticated software analysis tools. The sensor suite of IRLooK System includes imaging and non-imaging radiometers and a spectroradiometer. Single or simultaneous multiple in-band measurements as well as high radiant intensity measurements can be performed. The system provides detailed information on the spectral, spatial and temporal infrared signature characteristics of the targets. It also determines IR Decoy characteristics. The system is equipped with a high quality field proven two-axes tracking mount to facilitate target tracking. Manual or automatic tracking is achieved by using a passive imaging tracker. The system also includes a high quality weather station and field-calibration equipment including cavity and extended area blackbodies. The units composing the system are mounted on flat-bed trailers and the complete system is designed to be transportable by large body aircraft.

  17. Advances in high-performance cryocoolers and production variants at Raytheon Infrared Operations

    NASA Astrophysics Data System (ADS)

    Ross, Bradley A.; Black, Stephen H.

    2001-10-01

    Raytheon has consolidated the products and expertise of the former Hughes Mahwah (Magnavox) and Torrance cryocooler operations to the Raytheon Infrared Operations (RIO) located in Goleta, CA (formerly SBRC). Co-location of the cryocooler operations with the detector/dewar operations yields infrared systems with reduced cost. This paper describes the current capabilities of the linear and rotary cryocooler products as well as developments underway and planned. Development goals include cost reduction, high performance while operating in extreme environmental conditions (> 90°C skin temperatures), and long life (> 20,000 hrs). Technologies developed by a Raytheon sister division for space cryocoolers are now being applied to tactical cryocoolers at RIO. Data, specifications, and a technology roadmap for the product-line cryocoolers encompassing cooling capacities including 0.2-, 0.35-, 0.75-, 1.0- and 1.75-watt ranges will be shown.

  18. Analysis of high altitude clouds in the martian atmosphere based on Mars Climate Sounder observations

    NASA Astrophysics Data System (ADS)

    Puspitarini, L.; Määttänen, A.; Fouchet, T.; Kleinboehl, A.; Kass, D. M.; Schofield, J. T.

    2016-11-01

    High altitude clouds have been observed in the Martian atmosphere. However, their properties still remain to be characterized. Mars Climate Sounder (MCS) aboard Mars Reconnaissance Orbiter (MRO) is an instrument that measures radiances in the thermal infrared, both in limb and nadir views. It allows us to retrieve vertical profiles of radiance, temperature and aerosols. Using the MCS data and radiative transfer model coupled with an automated inversion routine, we can investigate the chemical composition of the high altitude clouds. We will present the first results on the properties of the clouds. CO2 ice is the best candidate to be the main component of some high altitude clouds due to the most similar spectral variation compared to water ice or dust, in agreement with previous studies. Using cloud composition of contaminated CO2 ice (dust core surrounded by CO2 ice) might improve the fitting result, but further study is needed.

  19. Applications of infrared technology; Proceedings of the Meeting, London, England, June 9, 10, 1988

    NASA Astrophysics Data System (ADS)

    Williams, T. L.

    1988-01-01

    Recent developments in thermal imaging and other infrared systems relating to military, industrial, medical, and scientific applications are reviewed. Papers are presented on a new thermal imager using a linear pyroelectric detector array; multichannel near infrared spectroradiometer; technological constraints on the use of thermal imagery for remote sensing; and infrared optical system of the improved stratospheric and mesospheric sounder. Other topics discussed include infrared thermography development for composite material evaluation; infrared process linescanner, and optical infrared starting radiometer.

  20. Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 1: Executive summary

    NASA Astrophysics Data System (ADS)

    1990-04-01

    The laser atmospheric wind sounder (LAWS) will provide a new space based capability for the direct measurement of atmospheric winds in the troposphere. LAWS will make a major contribution toward advancing the understanding and prediction of the total Earth system and NASA's Earth Observing System (EOS) Program. LAWS is designed to measure a fundamental atmospheric parameter required to advance weather forecasting accuracies and investigate global climatic change. LAWS has a potential added benefit of providing (global) concentration profiles of large aerosols including visible and subvisible cirrus clouds, volcanic dust, smoke, and other pollutants. The objective of this Phase One study was to develop a LAWS concept and configuration. The instrument design is outlined in this first volume of three.

  1. Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The laser atmospheric wind sounder (LAWS) will provide a new space based capability for the direct measurement of atmospheric winds in the troposphere. LAWS will make a major contribution toward advancing the understanding and prediction of the total Earth system and NASA's Earth Observing System (EOS) Program. LAWS is designed to measure a fundamental atmospheric parameter required to advance weather forecasting accuracies and investigate global climatic change. LAWS has a potential added benefit of providing (global) concentration profiles of large aerosols including visible and subvisible cirrus clouds, volcanic dust, smoke, and other pollutants. The objective of this Phase One study was to develop a LAWS concept and configuration. The instrument design is outlined in this first volume of three.

  2. Film handling procedures for Apollo 17 lunar sounder

    NASA Technical Reports Server (NTRS)

    Weinstein, M. S.

    1972-01-01

    Film handling procedures for the Apollo 17 Lunar Sounder are itemized, including purchase of flight film, establishment of processing standards, transportation of flight films, flight film certification, application of pre- and post-sensitometry, film loading and downloading, film processing, titling, and duplication.

  3. Results of the international ionospheric Doppler sounder network

    NASA Astrophysics Data System (ADS)

    Lastovicka, Jan; Chum, Jaroslav

    2016-07-01

    This paper summarizes main recent results reached by the Czech-lead international network of ionospheric Doppler sounders. The network consists of Doppler sounders in the western half of Czechia (5 measuring paths, 3 frequencies with central receivers in Prague), northern Taiwan (3 transmitters, two separated receivers, 1 frequency), and three similar systems (3 measuring paths with 1 receiver and 1 frequency) in Tucuman (north-western Argentina), Hermanus (the southernmost South Africa) and Luisville (northern South Africa). Three main areas of research have been (1) statistical properties of gravity waves, (2) ionospheric effects of earthquakes, and (3) low latitude/equatorial phenomena. Some results: (1) the theoretically expected dominance of gravity wave propagation against wind has been confirmed; (2) impact of the Tohoku 2001 M9.0 earthquake was registered in the ionosphere over the Czech Republic as long-period infrasound on the distance of about 9000 km from epicenter; analysis of ionospheric infrasound excited by the Nepal 2015 M7.8 earthquake observed by the Czech and Taiwan Doppler sounders showed that the intensity of ionospheric signal is significantly height dependent and that the Doppler shift depends not only on the advection (up and down motion) of the reflecting layer but also on the compression/rarefaction of the electron gas; (3) spread F structures observed by Doppler sounders in Tucuman and Taiwan (both under the crest of equatorial ionization anomaly) provide results consistent with S4 scintillation data and with previous optical, GPS and satellite measurements.

  4. PREMIER - Instrument Development of the Millimetre-Wave Limb Sounder MWLS

    NASA Astrophysics Data System (ADS)

    Gerber, D.; Kerridge, B. J.; Siddans, R.; Reburn, W. J.; Matheson, D. N.; Oldfield, M.; Cox, G. M.; Rea, S.; Murtagh, D.; Urban, J.

    2009-04-01

    The PREMIER (Process Exploration through Measurements of Infrared and millimetre-wave Emitted Radiation) mission is one of 6 candidates for ESA's 7th Earth Explorer Core Mission (due for launch ~ 2016), for which Phase 0 Assessment Studies have recently been undertaken. The mission proposes to make detailed measurements in the mid/upper troposphere and lower stratosphere in order to quantify processes controlling atmospheric global composition in this height range of particular importance to climate. PREMIER would consist of an infrared limb-imaging spectrometer which would observe 3D fields of trace gases, alongside a millimetre-wave limb sounder which would enable observations in the presence of most cirrus clouds, and also provide complementary trace gases. In this presentation we report on instrument development of the millimetre-wave limb sounder MWLS during Phase 0 of the PREMIER mission proposal. The PREMIER MWLS is a Swedish lead instrument (aka STEAM-R) co-developed by the Swedish Space Cooperation SSC and Chalmers University of Technology. Retrieval simulations have been performed at RAL to asses the radiometric performance of the MWLS. Based on that information, the observing system has been defined as a progressively spaced feed horn array. Physical optics simulations have been performed at Astrium UK to define the antenna pattern at the main reflector, as well as the quasi-optical layout of the antenna arrays and beam-shaping components. Hardware development has been pushed forward at RAL at several fronts to provide novel components for the instrument, most notably a sub-harmonic image rejection mixer (SHIRM).

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

    NASA Astrophysics Data System (ADS)

    Dwivedi, Sanjeev; Narayanan, M. S.; Venkat Ratnam, M.; Narayana Rao, D.

    2016-04-01

    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.

  6. High Vertically Resolved Atmospheric and Surface/Cloud Parameters Retrieved with Infrared Atmospheric Sounding Interferometer (IASI)

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

    The Joint Airborne IASI Validation Experiment (JAIVEx) was conducted during April 2007 mainly for validation of the IASI on the MetOp satellite. IASI possesses an ultra-spectral resolution of 0.25/cm and a spectral coverage from 645 to 2760/cm. Ultra-spectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. An advanced retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. This physical inversion scheme has been developed, dealing with cloudy as well as cloud-free radiance observed with ultraspectral infrared sounders, to simultaneously retrieve surface, atmospheric thermodynamic, and cloud microphysical parameters. A fast radiative transfer model, which applies to the cloud-free and/or clouded atmosphere, is used for atmospheric profile and cloud parameter retrieval. A one-dimensional (1-d) variational multi-variable inversion solution is used to improve an iterative background state defined by an eigenvector-regression-retrieval. The solution is iterated in order to account for non-linearity in the 1-d variational solution. It is shown that relatively accurate temperature and moisture retrievals are achieved below optically thin clouds. For optically thick clouds, accurate temperature and moisture profiles down to cloud top level are obtained. For both optically thin and thick cloud situations, the cloud top height can be retrieved with relatively high accuracy (i.e., error < 1 km). Preliminary retrievals of atmospheric soundings, surface properties, and cloud optical/microphysical properties with the IASI observations are obtained and presented. These retrievals will be further inter-compared with those obtained from airborne FTS system, such as the NPOESS Airborne Sounder Testbed - Interferometer (NAST-I), dedicated dropsondes, radiosondes, and ground based Raman Lidar. The

  7. Advances in Front-end Enabling Technologies for Thermal Infrared ` THz Torch' Wireless Communications

    NASA Astrophysics Data System (ADS)

    Hu, Fangjing; Lucyszyn, Stepan

    2016-09-01

    The thermal (emitted) infrared frequency bands (typically 20-40 and 60-100 THz) are best known for remote sensing applications that include temperature measurement (e.g. non-contacting thermometers and thermography), night vision and surveillance (e.g. ubiquitous motion sensing and target acquisition). This unregulated part of the electromagnetic spectrum also offers commercial opportunities for the development of short-range secure communications. The ` THz Torch' concept, which fundamentally exploits engineered blackbody radiation by partitioning thermally generated spectral radiance into pre-defined frequency channels, was recently demonstrated by the authors. The thermal radiation within each channel can be independently pulse-modulated, transmitted and detected, to create a robust form of short-range secure communications within the thermal infrared. In this paper, recent progress in the front-end enabling technologies associated with the THz Torch concept is reported. Fundamental limitations of this technology are discussed; possible engineering solutions for further improving the performance of such thermal-based wireless links are proposed and verified either experimentally or through numerical simulations. By exploring a raft of enabling technologies, significant enhancements to both data rate and transmission range can be expected. With good engineering solutions, the THz Torch concept can exploit nineteenth century physics with twentieth century multiplexing schemes for low-cost twenty-first century ubiquitous applications in security and defence.

  8. High sensitivity far infrared laser diagnostics for the C-2U advanced beam-driven field-reversed configuration plasmas.

    PubMed

    Deng, B H; Beall, M; Schroeder, J; Settles, G; Feng, P; Kinley, J S; Gota, H; Thompson, M C

    2016-11-01

    A high sensitivity multi-channel far infrared laser diagnostics with switchable interferometry and polarimetry operation modes for the advanced neutral beam-driven C-2U field-reversed configuration (FRC) plasmas is described. The interferometer achieved superior resolution of 1 × 10(16) m(-2) at >1.5 MHz bandwidth, illustrated by measurement of small amplitude high frequency fluctuations. The polarimetry achieved 0.04° instrument resolution and 0.1° actual resolution in the challenging high density gradient environment with >0.5 MHz bandwidth, making it suitable for weak internal magnetic field measurements in the C-2U plasmas, where the maximum Faraday rotation angle is less than 1°. The polarimetry resolution data is analyzed, and high resolution Faraday rotation data in C-2U is presented together with direct evidences of field reversal in FRC magnetic structure obtained for the first time by a non-perturbative method.

  9. Identification of fungal phytopathogens using Fourier transform infrared-attenuated total reflection spectroscopy and advanced statistical methods

    NASA Astrophysics Data System (ADS)

    Salman, Ahmad; Lapidot, Itshak; Pomerantz, Ami; Tsror, Leah; Shufan, Elad; Moreh, Raymond; Mordechai, Shaul; Huleihel, Mahmoud

    2012-01-01

    The early diagnosis of phytopathogens is of a great importance; it could save large economical losses due to crops damaged by fungal diseases, and prevent unnecessary soil fumigation or the use of fungicides and bactericides and thus prevent considerable environmental pollution. In this study, 18 isolates of three different fungi genera were investigated; six isolates of Colletotrichum coccodes, six isolates of Verticillium dahliae and six isolates of Fusarium oxysporum. Our main goal was to differentiate these fungi samples on the level of isolates, based on their infrared absorption spectra obtained using the Fourier transform infrared-attenuated total reflection (FTIR-ATR) sampling technique. Advanced statistical and mathematical methods: principal component analysis (PCA), linear discriminant analysis (LDA), and k-means were applied to the spectra after manipulation. Our results showed significant spectral differences between the various fungi genera examined. The use of k-means enabled classification between the genera with a 94.5% accuracy, whereas the use of PCA [3 principal components (PCs)] and LDA has achieved a 99.7% success rate. However, on the level of isolates, the best differentiation results were obtained using PCA (9 PCs) and LDA for the lower wavenumber region (800-1775 cm-1), with identification success rates of 87%, 85.5%, and 94.5% for Colletotrichum, Fusarium, and Verticillium strains, respectively.

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

    NASA Technical Reports Server (NTRS)

    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.

  11. Recent advances of mid-infrared compact, field deployable sensors: principles and applications

    NASA Astrophysics Data System (ADS)

    Tittel, Frank; Gluszek, Aleksander; Hudzikowski, Arkadiusz; Dong, Lei; Li, Chunguang; Patimisco, Pietro; Sampaolo, Angelo; Spagnolo, Vincenzo; Wojtas, Jacek

    2016-04-01

    The recent development of compact interband cascade lasers(ICLs) and quantum cascade lasers (QCLs) based trace gas sensors will permit the targeting of strong fundamental rotational-vibrational transitions in the mid-infrared which are one to two orders of magnitude more intense than transitions in the overtone and combination bands in the near-infrared. This has led to the design and fabrication of mid-infrared compact, field deployable sensors for use in the petrochemical industry, environmental monitoring and atmospheric chemistry. Specifically, the spectroscopic detection and monitoring of four molecular species, methane (CH4) [1], ethane (C2H6), formaldehyde (H2CO) [2] and hydrogen sulphide (H2S) [3] will be described. CH4, C2H6 and H2CO can be detected using two detection techniques: mid-infrared tunable laser absorption spectroscopy (TDLAS) using a compact multi-pass gas cell and quartz enhanced photoacoustic spectroscopy (QEPAS). Both techniques utilize state-of-the-art mid-IR, continuous wave (CW), distributed feedback (DFB) ICLs and QCLs. TDLAS was performed with an ultra-compact 54.6m effective optical path length innovative spherical multipass gas cell capable of 435 passes between two concave mirrors separated by 12.5 cm. QEPAS used a small robust absorption detection module (ADM) which consists of a quartz tuning fork (QTF), two optical windows, gas inlet/outlet ports and a low noise frequency pre-amplifier. Wavelength modulation and second harmonic detection were employed for spectral data processing. TDLAS and QEPAS can achieve minimum detectable absorption losses in the range from 10-8 to 10-11cm-1/Hz1/2. Several recent examples of real world applications of field deployable gas sensors will be described. For example, an ICL based TDLAS sensor system is capable of detecting CH4 and C2H6 concentration levels of 1 ppb in a 1 sec. sampling time, using an ultra-compact, robust sensor architecture. H2S detection was realized with a THz QEPAS sensor

  12. Advanced InSb monolithic Charge Coupled Infrared Imaging Devices (CCIRID)

    NASA Technical Reports Server (NTRS)

    Koch, T. L.; Thom, R. D.; Parrish, W. D.

    1981-01-01

    The continued development of monolithic InSb charge coupled infrared imaging devices (CCIRIDs) is discussed. The processing sequence and structural design of 20-element linear arrays are discussed. Also, results obtained from radiometric testing of the 20-element arrays using a clamped sample-and-hold output circuit are reported. The design and layout of a next-generation CCIRID chip are discussed. The major devices on this chip are a 20 by 16 time-delay-and-integration (TDI) area array and a 100-element linear imaging array. The development of a process for incorporating an ion implanted S(+) planar channel stop into the CCIRID structure and the development of a thin film transparent photogate are also addressed. The transparent photogates will increase quantum efficiency to greater than 70% across the 2.5 to 5.4 micrometer spectral region in future front-side illuminated CCIRIDs.

  13. Advanced fire observation by the Intelligent Infrared Sensor prototype FOCUS on the International Space Station

    NASA Astrophysics Data System (ADS)

    Oertel, D.; Haschberger, P.; Tank, V.; Lanzl, F.; Zhukov, B.; Jahn, H.; Briess, K.; Lorenz, E.; Roeser, H.-P.; Ginati, A.; Tobehn, C.; Schulte in den Bäumen, J.; Christmann, U.

    1999-01-01

    Current and planned operational space-borne Earth observation systems provide spatially, radiometrically or temporally crude data for the detection and monitoring of high temperature phenomena on the surface of our planet. High Temperature Events (HTE) very often cause environmental disasters. Such HTE are forest and savannah fires, fires of open coal mines, volcanic activities and others (e.g. fires of oil wells, pipelines etc.). A simultaneous co-registration of a combination of infrared (IR) and visible (VIS) channels is the key for a reliable autonomous on-board detection of High Temperature Events (HTE) on Earth surface, such as vegetation fires and volcano eruptions. This is the main feature of the FOCUS experiment. Furthermore there are ecology-oriented objectives of the FOCUS experiment mainly related to spectrometric/imaging remote inspection and parameter extraction of selected HTEs, and to the assessment of some ecological consequences of HTEs, such as aerosol and gas emission. Based on own experimental work and supported by Co-Investigators from Italy, Greece, France, Spain, Russia and Germany, DLR proposed in 1997 to use the International Space Station (ISS) in its early utilization phase as a platform and test-bed for an Intelligent Infrared Sensor prototype FOCUS of a future Environmental Disaster Recognition Satellite System. FOCUS is considered by ESA as an important mission combining a number of proven technologies and observation techniques to provide the scientific and operational user community with key data for the classification and monitoring of forest fires. FOCUS was selected as one of five European ``Groupings'' to be flown as an externally mounted payload during the early utilisation phase of the ISS. The FOCUS Phase A Study will be performed by OHB-System, DLR and Zeiss from September 1998 until May 1999.

  14. Spectrally Analyzed Embedded Infrared Fiber Optic Diagnostic of Advanced Composite Propellant Combustion

    DTIC Science & Technology

    2006-05-31

    observations, XM39. This nitramine composite propellant is 76 per cent RDX with most of the balance made up by the binder cellulose acetate butyrate and the...13 Figure 7 Predicted Model Spectrum for Pure Decomposition Gas at 6 atm with a 0.3 cm Absorption Path Length...program of in situ diagnostics and laboratory experiments has led to more advanced models of the gas phase processes in the dark zone and secondary flame

  15. The DST group ionospheric sounder replacement for JORN

    NASA Astrophysics Data System (ADS)

    Harris, T. J.; Quinn, A. D.; Pederick, L. H.

    2016-06-01

    The Jindalee Over-the-horizon Radar Network (JORN) is an integral part of Australia's national defense capability. JORN uses a real-time ionospheric model as part of its operations. The primary source of data for this model is a set of 13 vertical-incidence sounders (VIS) scattered around the Australian coast and inland locations. These sounders are a mix of Lowell digisonde portable sounder (DPS)-1 and DPS-4. Both of these sounders, the DPS-1 in particular, are near the end of their maintainable life. A replacement for these aging sounders was required as part of the ongoing sustainment program for JORN. Over the last few years the High-Frequency Radar Branch (HFRB) of the Defence Science and Technology (DST) Group, Australian Department of Defence, has been developing its own sounders based on its successful radar hardware technology. The DST Group VIS solution known as PRIME (Portable Remote Ionospheric Monitoring Equipment) is a 100% duty cycle, continuous wave system that receives the returned ionospheric signal while it is still transmitting and operates the receiver in the near field of the transmitter. Of considerable importance to a successful VIS is the autoscaling software, which takes the ionogram data and produces an ionogram trace (group delay as a function of frequency), and from that produces a set of ionospheric parameters that represent the (bottomside) overhead electron density profile. HFRB has developed its own robust autoscaling software. The performance of DST Group's PRIME under a multitude of challenging ionospheric conditions has been studied. In December 2014, PRIME was trialed at a JORN VIS site collocated with the existing Lowell Digisonde DPS-1. This side-by-side testing determined that PRIME was fit for purpose. A summary of the results of this comparison and example PRIME output will be discussed. Note that this paper compares PRIME with the 25 year old Lowell Digisonde DPS-1, which is planned to be replaced. Our future plans include

  16. Cortical Signal Analysis and Advances in Functional Near-Infrared Spectroscopy Signal: A Review

    PubMed Central

    Kamran, Muhammad A.; Mannan, Malik M. Naeem; Jeong, Myung Yung

    2016-01-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging modality that measures the concentration changes of oxy-hemoglobin (HbO) and de-oxy hemoglobin (HbR) at the same time. It is an emerging cortical imaging modality with a good temporal resolution that is acceptable for brain-computer interface applications. Researchers have developed several methods in last two decades to extract the neuronal activation related waveform from the observed fNIRS time series. But still there is no standard method for analysis of fNIRS data. This article presents a brief review of existing methodologies to model and analyze the activation signal. The purpose of this review article is to give a general overview of variety of existing methodologies to extract useful information from measured fNIRS data including pre-processing steps, effects of differential path length factor (DPF), variations and attributes of hemodynamic response function (HRF), extraction of evoked response, removal of physiological noises, instrumentation, and environmental noises and resting/activation state functional connectivity. Finally, the challenges in the analysis of fNIRS signal are summarized. PMID:27375458

  17. Advancing energy cane cell wall digestibility screening by near-infrared spectroscopy.

    PubMed

    Chong, Barrie Fong; O'Shea, Michael G

    2013-10-01

    Breeding energy cane for cellulosic biofuel production involves manipulating various traits. An important trait to optimize is cell wall degradability as defined by enzymatic hydrolysis. We investigated the feasibility of using near-infrared spectroscopy (NIRS) combined with multivariate calibration to predict energy cane cell wall digestibility based upon fiber samples from a range of sugarcane genotypes and related species. These samples produced digestibility values ranging between 6 and 31%. To preserve the practicality of the technique, spectra obtained from crudely prepared samples were used. Various spectral pre-processing methods were tested, with the best NIRS calibration obtained from second derivative, orthogonal signal-corrected spectra. Model performance was evaluated by cross-validation and independent validation. Large differences between the performance results from the two validation approaches indicated that the model was sensitive to the choice of test data. This may be remedied by using a larger calibration training set containing diverse sample types. The best result was obtained through independent validation which produced a R(2) value of 0.86, a root mean squared error of prediction (RMSEP) of 1.59, and a ratio of prediction to deviation (RPD) of 2.7. This study has demonstrated that it is feasible and practical to use NIRS to predict energy cane cell wall digestibility.

  18. Recent advances in near-infrared fluorescence-guided imaging surgery using indocyanine green.

    PubMed

    Namikawa, Tsutomu; Sato, Takayuki; Hanazaki, Kazuhiro

    2015-12-01

    Near-infrared (NIR) fluorescence imaging has better tissue penetration, allowing for the effective rejection of excitation light and detection deep inside organs. Indocyanine green (ICG) generates NIR fluorescence after illumination by an NIR ray, enabling real-time intraoperative visualization of superficial lymphatic channels and vessels transcutaneously. The HyperEye Medical System (HEMS) can simultaneously detect NIR rays under room light to provide color imaging, which enables visualization under bright light. Thus, NIR fluorescence imaging using ICG can provide for excellent diagnostic accuracy in detecting sentinel lymph nodes in cancer and microvascular circulation in various ischemic diseases, to assist us with intraoperative decision making. Including HEMS in this system could further improve the sentinel lymph node mapping and intraoperative identification of blood supply in reconstructive organs and ischemic diseases, making it more attractive than conventional imaging. Moreover, the development of new laparoscopic imaging systems equipped with NIR will allow fluorescence-guided surgery in a minimally invasive setting. Future directions, including the conjugation of NIR fluorophores to target specific cancer markers might be realistic technology with diagnostic and therapeutic benefits.

  19. Next Generation Grating Spectrometer Sounders for LEO and GEO

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.

    2011-01-01

    AIRS and MODIS are widely used for weather, climate, composition, carbon cycle, cross-calibration, and applications. The community asking for new capability in the 2020 timeframe, capabilities desired: (1) Hyperspectral UV to LWIR, High Spatial ?1km IFOV (2) Maximize Synergies of Solar Reflected and IR. Synergies with OCO-2. We expect more users and applications of next gen LEO IR Sounder than GEO. These include: weather, climate, GHG monitoring, aviation, disaster response. There is a new direction for imagers and sounders: (1) Separate Vis/NIR/SWIR from MWIR/LWIR instruments reduces technology risk and complexity. (2) Expect Costs to be lower than CrIS & VIIRS Some additional ideas to reduce costs include: (1) minimum set of requirements (2) mini-grating spectrometers. supports constellation for higher revisit (3) new technology to reduce instrument size (large format fpa's) (4) hosted payloads

  20. The topside sounder database - Data screening and systematic biases

    NASA Astrophysics Data System (ADS)

    Verhulst, Tobias; Stankov, Stanimir M.

    2013-06-01

    The ionospheric topside sounder measurement database developed at the US National Space Science Data Center (NSSDC) is a valuable source of information when investigating the composition and complex dynamics of the upper ionosphere. The database is increasingly used by many scientists around the world for both research and development of empirical models. However, there is always a danger of indiscriminately using the data without properly assessing the data quality and applicability for a given purpose. This paper is concerned with the issue of data screening and pre-processing of the Alouette/ISIS topside sounder database. An overview of the original database availability and formatting is given and the use of solar and geomagnetic indices is discussed. Data screening procedures, concerning detection and handling of erroneous profiles, are also presented. Special attention is drawn to the systematic biases observed in the database and the possibilities for their removal.

  1. High resolution microwave spectrometer sounder (HIMSS), volume 1, book 2

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The following topics are presented with respect to the high resolution microwave spectrometer sounder (HIMSS) that is to be used as an instrument for NASA's Earth Observing System (EOS): (1) preliminary program plans; (2) contract end item (CEI) specification; and (3) the instrument interface description document. Under the preliminary program plans section, plans dealing with the following subject areas are discussed: spares, performance assurance, configuration management, software implementation, contamination, calibration management, and verification.

  2. Influence of geophysical factors on oblique-sounder ionospheric characteristics

    SciTech Connect

    Baranets, A.N.; Blagoveshchenskaya, N.F.; Borisova, T.D.; Bubnov, V.A.

    1988-10-01

    The purpose of this paper is to study the influence of geophysical factors, including magnetoionospheric disturbances, on decameter wave propagation over extended paths using oblique sounding (OS) data, and also to compare experimental and calculated OS ionograms for various conditions of radio waver propagation (season, time of day). Variations of oblique-sounder ionospheric characteristics along a 9000 km long subauroral path for various geophysical conditions are considered. A comparison is made of experimental and calculated ionograms of oblique sounding.

  3. The Mars Climate Sounder on the Mars Reconnaissance Orbiter

    NASA Astrophysics Data System (ADS)

    McCleese, D.; Taylor, F.; Schofield, J.; Calcutt, S.

    2003-04-01

    There remains a need for an intensive effort to obtain a climatology of the martian atmosphere. This objective was to have been accomplished with the Mars Observer and with the Mars Climatology Orbiter, both of which failed at Mars. In 2005, the Mars Reconnaissance Orbiter will carry the Mars Climate Sounder (MCS) to aquire the necessary measurements of the vertical profiles of atmospheric temperature, water vapor, dust and condensates. This paper describes the climate objectives and measurement approach of MCS.

  4. High resolution microwave spectrometer sounder (HIMSS), volume 1, book 1

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The following topics are presented with respect to the high resolution microwave spectrometer sounder (HIMSS) that is to be used as an instrument for NASA's Earth Observing System (EOS): (1) an instrument overview; (2) an instrument description; (3) the instrument's conceptual design; (4) technical risks and offsets; (5) instrument reliability; (6) commands and telemetry; (7) mass and power budgets; (8) integration and test program; (9) program implementation; and (10) phase CD schedule.

  5. The Apollo 17 Lunar Sounder. [lunar orbit coherent radar experiment

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.; Brown, W. E., Jr.; Jordan, R.; Adams, G. F.; Jackson, P.; Peeples, W. J.; Porcello, L. J.; Ryu, J.; Eggleton, R. E.; Schaber, G.

    1973-01-01

    The Apollo Lunar Sounder Experiment, a coherent radar operated from lunar orbit during the Apollo 17 mission, has scientific objectives of mapping lunar subsurface structure, surface profiling, surface imaging, and galactic noise measurement. Representative results from each of the four disciplines are presented. Subsurface reflections have been interpreted in both optically and digitally processed data. Images and profiles yield detailed selenomorphological information. The preliminary galactic noise results are consistent with earlier measurements by other workers.

  6. Sonic depth sounder for laboratory and field use

    USGS Publications Warehouse

    Richardson, E.V.; Simons, Daryl B.; Posakony, G.J.

    1961-01-01

    The laboratory investigation of roughness in alluvial channels has led to the development of a special electronic device capable of mapping the streambed configuration under dynamic conditions. This electronic device employs an ultrasonic pulse-echo principle, similar to that of a fathometer, that utilizes microsecond techniques to give high accuracy in shallow depths. This instrument is known as the sonic depth sounder and was designed to cover a depth range of 0 to 4 feet with an accuracy of ? 0.5 percent. The sonic depth sounder is capable of operation at frequencies of 500, 1,000 and 2,000 kilocycles. The ultrasonic beam generated at the transducer is designed to give a minimum-diameter interrogating signal over the extended depth range. The information obtained from a sonic depth sounder is recorded on a strip-chart recorder. This permanent record allows an analysis to be made of the streambed configuration under different dynamic conditions. The model 1024 sonic depth sounder was designed principally as a research instrument to meet laboratory needs. As such, it is somewhat limited in its application as a field instrument on large streams and rivers. The principles employed in this instrument, however, have many potentials for field applications such as the indirect measurement of bed load when the bed roughness is ripples and (or) dunes, depth measurement, determination of bed configuration, and determination of depth of scour around bridge piers and abutments. For field application a modification of the present system into a battery-operated lightweight instrument designed to operate at a depth range of 0 to 30 feet is possible and desirable.

  7. Efficient simultaneous image deconvolution and upsampling algorithm for low-resolution microwave sounder data

    NASA Astrophysics Data System (ADS)

    Qin, Jing; Yanovsky, Igor; Yin, Wotao

    2015-01-01

    Microwave imaging has been widely used in the prediction and tracking of hurricanes, typhoons, and tropical storms. Due to the limitations of sensors, the acquired remote sensing data are usually blurry and have relatively low resolution, which calls for the development of fast algorithms for deblurring and enhancing the resolution. We propose an efficient algorithm for simultaneous image deconvolution and upsampling for low-resolution microwave hurricane data. Our model involves convolution, downsampling, and the total variation regularization. After reformulating the model, we are able to apply the alternating direction method of multipliers and obtain three subproblems, each of which has a closed-form solution. We also extend the framework to the multichannel case with the multichannel total variation regularization. A variety of numerical experiments on synthetic and real Advanced Microwave Sounding Unit and Microwave Humidity Sounder data were conducted. The results demonstrate the outstanding performance of the proposed method.

  8. Near-infrared-excited confocal Raman spectroscopy advances in vivo diagnosis of cervical precancer.

    PubMed

    Duraipandian, Shiyamala; Zheng, Wei; Ng, Joseph; Low, Jeffrey J H; Ilancheran, Arunachalam; Huang, Zhiwei

    2013-06-01

    Raman spectroscopy is a unique optical technique that can probe the changes of vibrational modes of biomolecules associated with tissue premalignant transformation. This study evaluates the clinical utility of confocal Raman spectroscopy over near-infrared (NIR) autofluorescence (AF) spectroscopy and composite NIR AF/Raman spectroscopy for improving early diagnosis of cervical precancer in vivo at colposcopy. A rapid NIR Raman system coupled with a ball-lens fiber-optic confocal Raman probe was utilized for in vivo NIR AF/Raman spectral measurements of the cervix. A total of 1240 in vivo Raman spectra [normal (n=993), dysplasia (n=247)] were acquired from 84 cervical patients. Principal components analysis (PCA) and linear discriminant analysis (LDA) together with a leave-one-patient-out, cross-validation method were used to extract the diagnostic information associated with distinctive spectroscopic modalities. The diagnostic ability of confocal Raman spectroscopy was evaluated using the PCA-LDA model developed from the significant principal components (PCs) [i.e., PC4, 0.0023%; PC5, 0.00095%; PC8, 0.00022%, (p<0.05)], representing the primary tissue Raman features (e.g., 854, 937, 1095, 1253, 1311, 1445, and 1654 cm(-1)). Confocal Raman spectroscopy coupled with PCA-LDA modeling yielded the diagnostic accuracy of 84.1% (a sensitivity of 81.0% and a specificity of 87.1%) for in vivo discrimination of dysplastic cervix. The receiver operating characteristic curves further confirmed that the best classification was achieved using confocal Raman spectroscopy compared to the composite NIR AF/Raman spectroscopy or NIR AF spectroscopy alone. This study illustrates that confocal Raman spectroscopy has great potential to improve early diagnosis of cervical precancer in vivo during clinical colposcopy.

  9. Thermal impact of near-infrared laser in advanced noninvasive optical brain imaging

    PubMed Central

    Nourhashemi, Mina; Mahmoudzadeh, Mahdi; Wallois, Fabrice

    2016-01-01

    Abstract. The propagation of laser light in human tissues is an important issue in functional optical imaging. We modeled the thermal effect of different laser powers with various spot sizes and different head tissue characteristics on neonatal and adult quasirealistic head models. The photothermal effect of near-infrared laser (800 nm) was investigated by numerical simulation using finite-element analysis. Our results demonstrate that the maximum temperature increase on the brain for laser irradiance between 0.127 (1 mW) and 12.73  W/cm2 (100 mW) at a 1 mm spot size, ranged from 0.0025°C to 0.26°C and from 0.03°C to 2.85°C at depths of 15.9 and 4.9 mm in the adult and neonatal brain, respectively. Due to the shorter distance of the head layers from the neonatal head surface, the maximum temperature increase was higher in the neonatal brain than in the adult brain. Our results also show that, at constant power, spot size changes had a lesser heating effect on deeper tissues. While the constraints for safe laser irradiation to the brain are dictated by skin safety, these results can be useful to optimize laser parameters for a variety of laser applications in the brain. Moreover, combining simulation and adequate in vitro experiments could help to develop more effective optical imaging to avoid possible tissue damage. PMID:27115020

  10. Advances in R&D in near-infrared spectroscopy in Japan

    NASA Astrophysics Data System (ADS)

    Kawano, Sumio; Iwamoto, Mutsuo

    1991-02-01

    More than 20 years ago when Mr. K. H. Norris firstly introduced the near infrared spectroscopy (NIRS) as a powerful technology in the field of composition analysis of cereals those who were interested in the area of classical spectroscopy would not like to recognize its potential. This tendency still remains at present however it leaves no room for doubt that from viewpoints of applied spectroscopy the NIRS has consolidated its position. From a viewpoint of NIRS application in the field of nondestructive or non invasive measuring techniques history of this technology is only the last decade in Japan. However since the technology was firstly introduced to composition analysis of agricultural commodities in the same manner as in other countries R and D have been growing more actively in diversified fields such as agriculture and industry as well as medical science. In addition the NIRS technology are becoming of general interest by combining other techniques to create various hyphenated instrumentations such as FTNIR MCFTNIR NIRCT and NIR-NMR. In this paper new trends of R D on NIR spectroscopy which are being conducted in Japan will be reviewed. 2. S1JMMARY OF PRESENT R D ON NIRS IN JAPAN NIRS applications reported in the last 3 years are summarized in Table 1. Table 1 Applications of NIRS in Japan Application for Agriculture Taste evaluation of rice and coffee Determination of chemical compositions rice for breeding Determination of chemical compositions in tea Determination of sugar contents in intact peaches Japanese pears Satsuma oranges and apples Determination of sugars and acids in intact tomatoes Determination of forage composition Application for Industry Analysis of state of water in foods Application of analyzing Maillard Reaction''s Process Pattern recognition of NIR spectra as related to process control of roasting coffee beans Quality control of tea processing Determination of moisture content of Surimi products 2 / SPIE Vol. 1379 Optics in Agriculture

  11. Advanced shortwave infrared and Raman hyperspectral sensors for homeland security and law enforcement operations

    NASA Astrophysics Data System (ADS)

    Klueva, Oksana; Nelson, Matthew P.; Gardner, Charles W.; Gomer, Nathaniel R.

    2015-05-01

    Proliferation of chemical and explosive threats as well as illicit drugs continues to be an escalating danger to civilian and military personnel. Conventional means of detecting and identifying hazardous materials often require the use of reagents and/or physical sampling, which is a time-consuming, costly and often dangerous process. Stand-off detection allows the operator to detect threat residues from a safer distance minimizing danger to people and equipment. Current fielded technologies for standoff detection of chemical and explosive threats are challenged by low area search rates, poor targeting efficiency, lack of sensitivity and specificity or use of costly and potentially unsafe equipment such as lasers. A demand exists for stand-off systems that are fast, safe, reliable and user-friendly. To address this need, ChemImage Sensor Systems™ (CISS) has developed reagent-less, non-contact, non-destructive sensors for the real-time detection of hazardous materials based on widefield shortwave infrared (SWIR) and Raman hyperspectral imaging (HSI). Hyperspectral imaging enables automated target detection displayed in the form of image making result analysis intuitive and user-friendly. Application of the CISS' SWIR-HSI and Raman sensing technologies to Homeland Security and Law Enforcement for standoff detection of homemade explosives and illicit drugs and their precursors in vehicle and personnel checkpoints is discussed. Sensing technologies include a portable, robot-mounted and standalone variants of the technology. Test data is shown that supports the use of SWIR and Raman HSI for explosive and drug screening at checkpoints as well as screening for explosives and drugs at suspected clandestine manufacturing facilities.

  12. Near-infrared-excited confocal Raman spectroscopy advances in vivo diagnosis of cervical precancer

    NASA Astrophysics Data System (ADS)

    Duraipandian, Shiyamala; Zheng, Wei; Ng, Joseph; Low, Jeffrey J. H.; Ilancheran, Arunachalam; Huang, Zhiwei

    2013-06-01

    Raman spectroscopy is a unique optical technique that can probe the changes of vibrational modes of biomolecules associated with tissue premalignant transformation. This study evaluates the clinical utility of confocal Raman spectroscopy over near-infrared (NIR) autofluorescence (AF) spectroscopy and composite NIR AF/Raman spectroscopy for improving early diagnosis of cervical precancer in vivo at colposcopy. A rapid NIR Raman system coupled with a ball-lens fiber-optic confocal Raman probe was utilized for in vivo NIR AF/Raman spectral measurements of the cervix. A total of 1240 in vivo Raman spectra [normal (n=993), dysplasia (n=247)] were acquired from 84 cervical patients. Principal components analysis (PCA) and linear discriminant analysis (LDA) together with a leave-one-patient-out, cross-validation method were used to extract the diagnostic information associated with distinctive spectroscopic modalities. The diagnostic ability of confocal Raman spectroscopy was evaluated using the PCA-LDA model developed from the significant principal components (PCs) [i.e., PC4, 0.0023% PC5, 0.00095% PC8, 0.00022%, (p<0.05)], representing the primary tissue Raman features (e.g., 854, 937, 1095, 1253, 1311, 1445, and 1654 cm-1). Confocal Raman spectroscopy coupled with PCA-LDA modeling yielded the diagnostic accuracy of 84.1% (a sensitivity of 81.0% and a specificity of 87.1%) for in vivo discrimination of dysplastic cervix. The receiver operating characteristic curves further confirmed that the best classification was achieved using confocal Raman spectroscopy compared to the composite NIR AF/Raman spectroscopy or NIR AF spectroscopy alone. This study illustrates that confocal Raman spectroscopy has great potential to improve early diagnosis of cervical precancer in vivo during clinical colposcopy.

  13. A laser sounder for U.S. Navy helicopters

    NASA Technical Reports Server (NTRS)

    Harris, Michael M.; Mesick, Hillary C.; Byrnes, H. Jerry; Curran, Thomas P.; Contarino, V. Michael

    1987-01-01

    The design and operating principles of the laser sounder developed for use in airborne coastal-zone bathymetric surveys with a U.S. Navy P-3 aircraft are described and illustrated with diagrams. The sounder components are listed and characterized, including the Nd:YAG transmitter (operating at 532 nm for bottom ranging and 1.064 microns for surface ranging), the scanning transceiver, the 10 x 6-inch-aperture controlled-FOV receiver/digitizer, the constant-fraction discriminator, the time-to-digital converter, the navigation and data-recording subsystems, and the parallel distributed processing computer (comprising a data collection and control system and a real-time processing system). Consideration is also given to the phase-I and phase-II data-reduction software being developed to process the approximately 228 million soundings to be obtained annually. The sounder can be used day or night to sound clear ocean water up to 20 m deep.

  14. Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

    NASA Technical Reports Server (NTRS)

    Zhu, Jiang; Stevens, E.; Zhang, X.; Zavodsky, B. T.; Heinrichs, T.; Broderson, D.

    2014-01-01

    A case study and monthly statistical analysis using sounder data assimilation to improve the Alaska regional weather forecast model are presented. Weather forecast in Alaska faces challenges as well as opportunities. Alaska has a large land with multiple types of topography and coastal area. Weather forecast models must be finely tuned in order to accurately predict weather in Alaska. Being in the high-latitudes provides Alaska greater coverage of polar orbiting satellites for integration into forecasting models than the lower 48. Forecasting marine low stratus clouds is critical to the Alaska aviation and oil industry and is the current focus of the case study. NASA AIRS/CrIS sounder profiles data are used to do data assimilation for the Alaska regional weather forecast model to improve Arctic marine stratus clouds forecast. Choosing physical options for the WRF model is discussed. Preprocess of AIRS/CrIS sounder data for data assimilation is described. Local observation data, satellite data, and global data assimilation data are used to verify and/or evaluate the forecast results by the MET tools Model Evaluation Tools (MET).

  15. Optical design of a near-infrared imaging spectropolarimeter for the Advanced Technology Solar Telescope

    NASA Astrophysics Data System (ADS)

    Greco, Vincenzo; Cavallini, Fabio

    2013-06-01

    In designing the optics of an imaging multi-etalon spectropolarimeter as a post-focus instrument for the Advanced Technology Solar Telescope (ATST), many constraints must be considered. Among these are the large entrance pupil diameter of the telescope (4 m), the demanded large field of view (≥90 arc sec), high spectral resolving power (≥200,000), and limited field-dependent blue-shift of the instrumental profile [≤3 full width at half maximum (FWHM)], which require Fabry-Perot interferometers of large diameter (≥200 mm), lighted by highly collimated beams. This implies large optical elements and long optical paths. Moreover, to use interference pre-filters with a relatively small diameter (≤70 mm) and placed between the interferometers to reduce the inter-reflections in axial-mount, a "pupil adapter" must be included with a further increase of the optical path length. Although a multi-etalon spectropolarimeter works in quasi-monochromatic light, the Fraunhofer lines of interest cover a wide range of wavelengths (850 to 1650 nm), which demands a good chromatic aberration control. A low instrumental polarization (≤0.5%) is also required to allow a high polarimetric precision. Finally, some secondary optical paths are required to perform the initial instrumental setup and to secure the best instrumental performances. A diffraction-limited optical solution for ATST is described that fulfills all the above requirements in a relative small volume.

  16. Millimeter Wave Moisture Sounder Feasibility Study: The Effect of Cloud and Precipitation on Moisture Retrievals.

    DTIC Science & Technology

    1985-03-08

    D-A162 231 MILLIMETER WAVE MOISTURE SOUNDER FEASIBILITY STUDY- THE i/1 EFFECT OF CLOUD A (U) ATMOSPHERIC AND ENVIRONMENTAL RESEARCH INC CAMBRIDGE MA...34 ,,; - -., ,..-.,- -, ,.. . : .,,- ,.. ,- - - , . .. .-. ,=, .-,o.. .- .-,o ,-N . ,.-,."...,- ,,, .. .,..; .. ,., .:°B,.. ’ AFGL-TR-85-0040 MILLIMETER WAVE MOISTURE SOUNDER FEASIBILITY STUDY: THE EFFECT OF...REPORT A PERIOD COVERED Millimeter Wave Moisture Sounder Feasibility Final Report Study: The Effect of Cloud and Precipitation 8 Aug 1984-7 Feb 1985 on

  17. Radiometric comparison of Mars Climate Sounder and Thermal Emission spectrometer measurements

    NASA Astrophysics Data System (ADS)

    Bandfield, Joshua L.; Wolff, Michael J.; Smith, Michael D.; Schofield, John T.; McCleese, Daniel J.

    2013-07-01

    Mars Climate Sounder (MCS) nadir oriented thermal infrared and solar channel measurements are compared with Thermal Emission Spectrometer (TES) measurements across multiple Mars years. Thermal infrared measurements were compared by convolving the TES data using the MCS spectral band passes. The MCS solar channel measurements were calibrated using Compact Reconnaissance Imaging Spectrometer for Mars observations to provide the proper gain factor (3.09 × 10-3 W sr-1 m-2 μm-1). The comparisons of the datasets show that day and night surface and atmospheric temperatures are within 3 K over the course of 5 martian years, after accounting for the local time differences. Any potential interannual variations in global average temperature are masked by calibration and modeling uncertainties. Previous work attributed apparent interannual global surface and atmospheric temperature variations to major dust storm activity; however, this variation has since been attributed to a calibration error in the TES dataset that has been corrected. MCS derived Lambert albedos are slightly higher than TES measurements acquired over the same season and locations. Most of this difference can be attributed to the spectral response functions of MCS and TES. Consistent with previous work, global albedo is highly variable (˜6%) and this variability must be taken into account when determining long term global trends. Vertical aerosol distributions were also derived from the calibrated MCS visible channel limb measurements, demonstrating the utility of the MCS visible channel data for monitoring of aerosols.

  18. Applications of near-infrared spectroscopy in food safety evaluation and control: a review of recent research advances.

    PubMed

    Qu, Jia-Huan; Liu, Dan; Cheng, Jun-Hu; Sun, Da-Wen; Ma, Ji; Pu, Hongbin; Zeng, Xin-An

    2015-01-01

    Food safety is a critical public concern, and has drawn great attention in society. Consequently, developments of rapid, robust, and accurate methods and techniques for food safety evaluation and control are required. As a nondestructive and convenient tool, near-infrared spectroscopy (NIRS) has been widely shown to be a promising technique for food safety inspection and control due to its huge advantages of speed, noninvasive measurement, ease of use, and minimal sample preparation requirement. This review presents the fundamentals of NIRS and focuses on recent advances in its applications, during the last 10 years of food safety control, in meat, fish and fishery products, edible oils, milk and dairy products, grains and grain products, fruits and vegetables, and others. Based upon these applications, it can be demonstrated that NIRS, combined with chemometric methods, is a powerful tool for food safety surveillance and for the elimination of the occurrence of food safety problems. Some disadvantages that need to be solved or investigated with regard to the further development of NIRS are also discussed.

  19. MERTIS-thermal infrared imaging of Mercury: advances in mid-IR remote sensing technology for planetary exploration

    NASA Astrophysics Data System (ADS)

    Arnold, Gabriele E.; Hiesinger, Harald; Helbert, Jörn; Peter, Gisbert; Walter, Ingo

    2010-09-01

    MERTIS (MErcury Radiometer and Thermal infrared Imaging Spectrometer) is part of ESA's BepiColombo Mercury Planetary Orbiter mission to the innermost planet of the Solar system. MERTIS is designed to identify rock-forming minerals, to map the surface composition, and to study the surface temperature variations with an uncooled microbolometer detector in the hot environment of Mercury. MERTIS is an advanced IR instrument combining a pushbroom IR grating spectrometer (TIS) with a radiometer (TIR) sharing the same optics, instrument electronics and in-fight calibration components for a wavelength range of 7-14 and 7-40 μm, respectively. First results of the ongoing MESSENGER project at Mercury have shown a more complex geology and higher variability of features than previously thought. The MESSENGER studies have demonstrated the need to gain global high-resolution mid-IR spectral and temperature data to achieve a better understanding of the planetary genesis. The MERTIS measurements will acquire this currently missing data set. This article gives a summary of the instrument requirements and its design. We are reporting on the actual instrument development progress, and the status of system and subsystem qualification efforts.

  20. Diamonds are a spectroscopist's best friend: thin-film diamond mid-infrared waveguides for advanced chemical sensors/biosensors.

    PubMed

    Wang, Xiaofeng; Karlsson, Mikael; Forsberg, Pontus; Sieger, Markus; Nikolajeff, Fredrik; Österlund, Lars; Mizaikoff, Boris

    2014-08-19

    The first combination of mid-infrared (MIR) tunable quantum cascade lasers (tQCLs) with thin-film diamond strip waveguides (DSWGs) suitable for advanced chemical sensing/biosensing is demonstrated. The sensing system is composed of thin diamond films grown on surface-passivated Si wafers via chemical vapor deposition (CVD) and microstructured using inductively coupled plasma (ICP) etching, serving as photonic waveguides for radiation emitted by a broadly tunable quantum cascade laser (tQCL) in the spectral regime of 5.78-6.35 μm (1570-1730 cm(-1)). The characterization of the free-standing diamond waveguides reveals excellent transmission properties across a broad MIR band. As a proof of concept, the detection of acetone in D2O via evanescent field absorption is demonstrated achieving a limit of detection (LOD) as low as 200 pL, which indicates a significant sensitivity improvement compared to conventional MIR slab/strip waveguides reported to date. Providing characteristic absorption features within the tuning range of the tQCL, studies using anisaldehyde as an analyte further corroborate the potential of tQCL-DSWG-based chemical sensors/biosensors.

  1. Calibration of the Visible and Near-Infrared Channels of the Advanced Very High Resolution Radiometer (AVHRR) After Launch

    NASA Technical Reports Server (NTRS)

    Rao, C. R. Nagaraja; Chen, Jianhua

    1993-01-01

    The relative degradation in time of the visible(channel 1: approx.0.58-0.6 microns) and near-infrared(channel 2: approx. O.72-1.1 microns) channels of the Advanced Very High Resolution Radiometer(AVHRR), onboard the NOAA Polar-orbiting Operational Environmental Satellites(POES), has been determined, using the southeastern Libyan desert(21-23 deg N latitude; 28- 29 deg E longitude) as a time-invariant calibration target. A statistical procedure was used on the reflectance data for the two channels from the B3 data of the International Satellite Cloud Climatology Project(ISCCP) to obtain the degradation rates for the AVERRs on NOAA-7, -9, and -11 spacecraft. The degradation rates per year for channels 1 and 2 are respectively: 3.6% and 4.3%(NOAA-7); 5.9% and 3.5%(NOAA-9); and 1.2% and 2.0%(NOAA-11). The use of the degradation rates thus determined, in conjunction with 'absolute' calibrations obtained from congruent aircraft and satellite measurements, in the development of correction algorithms is illustrated with the AVHRR on the NOAA-9 spacecraft.

  2. Subminiature infrared detector translation stage

    NASA Technical Reports Server (NTRS)

    Bell, Alan D.

    1989-01-01

    This paper describes a precision subminiature three-axis translation stage used in the GOES Sounder to provide positional adjustment of 12 cooled infrared detectors. Four separate translation stages and detectors are packaged into a detector mechanism which has an overall size of 0.850 x 1.230 x 0.600 inches. Each translation stage is capable of + or - 0.015 inch motion in the X and Y axes and +0.050/-0.025 inch motion in the Z axis with a sensitivity of 0.0002 inches. The function of the detector translation stage allows real time detector signal peaking during Sounder alignment. The translation stage operates in a cryogenic environment under a 10 to the -6th torr vacuum.

  3. The microwave limb sounder for the Upper Atmosphere Research Satellite

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  5. The Behm Acoustic Sounder for Airplanes with Reference to Its Accuracy

    NASA Technical Reports Server (NTRS)

    Schreiber, Ernest

    1930-01-01

    Relative altimetry is of great importance for increasing the safety in aerial transportation, because it makes possible safe flying at night, by poor visibility, and when landing. Among the instruments of this type is the Behm sounder, which operates on an acoustic principle. Acoustic altimetry in general and the Behn sounder, in particular, are covered in this report.

  6. Advanced infrared astronomy

    NASA Technical Reports Server (NTRS)

    Mumma, M. J.; Deming, D.; Espenak, F.; Kostiuk, T.

    1986-01-01

    The CO2 laser heterodyne spectrometer was used at the 3-m IRTF on Mauna Kea to make measurements of Mars during the 1984 opposition. Analysis of the observations of the mesospheric non-thermal emission demonstrated the existence of a warming of the Mars polar mesosphere, similar to the seasonal effects which are well known to occur at the Earth's mesopause. A search for CO2 and NH3 on Comet Halley was done with the new Kitt Peak system as well as with the IRTF heterodyne system. A Lamb-dip absorption cell was designed and constructed. Its use will allow extreme frequency stabilization of the laser local oscillator, which will greatly facilitate measurements of winds and dynamical phenomena. The Lamb-dip cell was used at Kitt Peak to study zonal and meridional winds in the atmosphere of Venus. Water vapor was detected in Comet Halley using Fourier transform spectrometer. The 2.65 micrometer upsilon sub 3 band was seen in emission, confirming non-thermal-equilibrium excitation models for comets. A study was made of the variability of Jovian ethane emission. The average volume mixing ratio of ethane in the Jovian stratosphere was found to be 3x10 to the -6 power, with the greatest variability seen in the auroral regions.

  7. A Comparison of the Red Green Blue Air Mass Imagery and Hyperspectral Infrared Retrieved Profiles

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Folmer, Michael; Dunion, Jason

    2014-01-01

    The Red Green Blue (RGB) Air Mass imagery is derived from multiple channels or paired channel differences. Multiple channel products typically provide additional information than a single channel can provide alone. The RGB Air Mass imagery simplifies the interpretation of temperature and moisture characteristics of air masses surrounding synoptic and mesoscale features. Despite the ease of interpretation of multiple channel products, the combination of channels and channel differences means the resulting product does not represent a quantity or physical parameter such as brightness temperature in conventional single channel satellite imagery. Without a specific quantity to reference, forecasters are often confused as to what RGB products represent. Hyperspectral infrared retrieved profiles of temperature, moisture, and ozone can provide insight about the air mass represented on the RGB Air Mass product and provide confidence in the product and representation of air masses despite the lack of a quantity to reference for interpretation. This study focuses on RGB Air Mass analysis of Hurricane Sandy as it moved north along the U.S. East Coast, while transitioning to a hybrid extratropical storm. Soundings and total column ozone retrievals were analyzed using data from the Cross-track Infrared and Advanced Technology Microwave Sounder Suite (CrIMSS) on the Suomi National Polar Orbiting Partnership satellite and the Atmospheric Infrared Sounder (AIRS) on the National Aeronautics and Space Administration Aqua satellite along with dropsondes that were collected from National Oceanic and Atmospheric Administration and Air Force research aircraft. By comparing these datasets to the RGB Air Mass, it is possible to capture quantitative information that could help in analyzing the synoptic environment enough to diagnose the onset of extratropical transition. This was done by identifying any stratospheric air intrusions (SAIs) that existed in the vicinity of Sandy as the wind

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

    NASA Technical Reports Server (NTRS)

    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.

  9. Upper tropospheric cloud systems determined from IR Sounders and their influence on the atmosphere

    NASA Astrophysics Data System (ADS)

    Stubenrauch, Claudia; Protopapadaki, Sofia; Feofilov, Artem; Velasco, Carola Barrientos

    2017-02-01

    Covering about 30% of the Earth, upper tropospheric clouds play a key role in the climate system by modulating the Earth's energy budget and heat transport. Infrared Sounders reliably identify cirrus down to an IR optical depth of 0.1. Recently LMD has built global cloud climate data records from AIRS and IASI observations, covering the periods from 2003-2015 and 2008-2015, respectively. Upper tropospheric clouds often form mesoscale systems. Their organization and properties are being studied by (1) distinguishing cloud regimes within 2° × 2° regions and (2) applying a spatial composite technique on adjacent cloud pressures, which estimates the horizontal extent of the mesoscale cloud systems. Convective core, cirrus anvil and thin cirrus of these systems are then distinguished by their emissivity. Compared to other studies of tropical mesoscale convective systems our data include also the thinner anvil parts, which make out about 30% of the area of tropical mesoscale convective systems. Once the horizontal and vertical structure of these upper tropospheric cloud systems is known, we can estimate their radiative effects in terms of top of atmosphere and surface radiative fluxes and by computing their heating rates.

  10. Nimbus-7 Stratospheric and Mesospheric Sounder (SAMS) experiment data user's guide

    NASA Technical Reports Server (NTRS)

    Taylor, F. W.; Rodgers, C. D.; Nutter, S. T.; Oslik, N.

    1989-01-01

    The Stratospheric and Mesospheric Sounder (SAMS) aboard Nimbus-7 observes infrared radiation from the atmospheric limb. Global upper atmosphere temperature profiles and vertical concentrations of H2O, NO, N2O, CH4 and CO2 are derived from these measurements. The status of all channels was carefully monitored. Temperature and composition were retrieved from the measurements by linearizing the direct equation about an a priori profile and using an optimum statistical estimator to find the most likely solution. The derived temperature and composition profiles are archived on two tape products whose file structure and record formats are described in detail. The gridded retrieved temperature tape (GRID-T) contains daily day and night average temperatures at 62 pressure levels in a 2.5 degree latitude by 10 degree longitude grid extending from 67.5 degrees N to 50 degrees S. The zonal mean methane and nitrous oxide composition tape (ZMT-G) contains zonal mean day and night average CH4 and N2O mixing ratios at 31 pressure levels for 2.5 degrees latitude zones extending from 67.5 degrees N to 50 degrees S.

  11. Science Goals and Mission Objectives of Nasa's Laser Atmospheric Wind Sounder Program

    NASA Technical Reports Server (NTRS)

    Baker, Wayman E.

    1992-01-01

    Knowledge of the global wind field is widely recognized as fundamental to advancing our understanding and prediction of the total Earth system. Yet, because wind profiles are primarily measured by land-based rawinsondes, the oceanic areas (covering three quarters of the Earth's surface) and many regions of the less developed southern hemisphere land areas are poorly observed. The gap between our requirements for wind data and their availability continues to widen. For example, as faster computers become available to model the atmosphere with ever increasing resolution and sophistication, our ability to model the atmosphere will be hampered by a lack of data, particularly wind profiles. In order to address this important deficiency in wind observations, NASA plans to construct the Laser Atmospheric Wind Sounder (LAWS) instrument, with deployment tentatively scheduled between 2002 and 2005 as part of NASA's Earth Observing System (EOS) mission. Addressed here is the importance of wind measurements for advancing our understanding and prediction of the total Earth System. The current characteristics of the LAWS instrument under study are also summarized.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  14. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions.

    PubMed

    Lockerbie, N A; Tokmakov, K V

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m(-1) was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain

  15. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions

    NASA Astrophysics Data System (ADS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m-1 was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain ratio

  16. Geo-STAR: A Geostationary Microwave Sounder for the Future

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn H.; Brown, S. T.; Dinardo, S. J.; Gaier, T. C.; Kangaslahti, P. P.; Tanner, A. B.

    2007-01-01

    The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a new Earth remote sensing instrument concept that has been under development at the Jet Propulsion Laboratory. First conceived in 1998 as a NASA New Millennium Program mission and subsequently developed in 2003-2006 as a proof-of-concept prototype under the NASA Instrument Incubator Program, it is intended to fill a serious gap in our Earth remote sensing capabilities - namely the lack of a microwave atmospheric sounder in geostationary orbit. The importance of such observations have been recognized by the National Academy of Sciences National Research Council, which recently released its report on a 'Decadal Survey' of NASA Earth Science activities1. One of the recommended missions for the next decade is a geostationary microwave sounder. GeoSTAR is well positioned to meet the requirements of such a mission, and because of the substantial investment NASA has already made in GeoSTAR technology development, this concept is fast approaching the necessary maturity for implementation in the next decade. NOAA is also keenly interested in GeoSTAR as a potential payload on its next series of geostationary weather satellites, the GOES-R series. GeoSTAR, with its ability to map out the three-dimensional structure of temperature, water vapor, clouds, precipitation and convective parameters on a continual basis, will significantly enhance our ability to observe hurricanes and other severe storms. In addition, with performance matching that of current and next generation of low-earth-orbiting microwave sounders, GeoSTAR will also provide observations important to the study of the hydrologic cycle, atmospheric processes and climate variability and trends. In particular, with GeoSTAR it will be possible to fully resolve the diurnal cycle. We discuss the GeoSTAR concept and basic design, the performance of the prototype, and a number of science applications that will be possible with GeoSTAR. The work reported

  17. Accurate, practical simulation of satellite infrared radiometer spectral data

    SciTech Connect

    Sullivan, T.J.

    1982-09-01

    This study's purpose is to determine whether a relatively simple random band model formulation of atmospheric radiation transfer in the infrared region can provide valid simulations of narrow interval satellite-borne infrared sounder system data. Detailed ozonesondes provide the pertinent atmospheric information and sets of calibrated satellite measurements provide the validation. High resolution line-by-line model calculations are included to complete the evaluation.

  18. Validation of nitrogen dioxide measurements from the Improved Stratospheric and Mesospheric Sounder

    NASA Astrophysics Data System (ADS)

    Reburn, W. J.; Remedios, J. J.; Morris, P. E.; Rodgers, C. D.; Taylor, F. W.; Kerridge, B. J.; Knight, R. J.; Ballard, J.; Kumer, J. B.; Massie, S. T.

    1996-04-01

    Measurements of nitrogen dioxide (NO2) from the Improved Stratospheric and Mesospheric Sounder (ISAMS) on the Upper Atmosphere Research Satellite (UARS) are assessed. Channel 5 of the instrument was dedicated to observations of nitrogen dioxide and employed pressure-modulation and wideband radiometry to make measurements at 6.2 μm. This dual technique allows simultaneous determination of nitrogen dioxide mixing ratio and the aerosol extinction coefficient at this wavelength and therefore provides nitrogen dioxide data even in the presence of heavy aerosol loading. Approximately 180 days of data, in the period from September 1991 to July 1992, were obtained with, typically, over 2600 profiles per day for each retrieved species, covering an altitude range of 100-0.01 mbar. In this paper the version 10 data are assessed and a full error analysis is described. Comparisons with the Cryogenic Limb Array Etalon Spectrometer (CLAES) on UARS and the Limb Infrared Monitor of the Stratosphere (LIMS) on Nimbus 7 are also presented. It is concluded that the morphology of the retrieved ISAMS fields is robust and consistent with concurrent as well as previous infrared satellite measurements. Random errors are estimated to be of the order of 10% for nighttime and 15% for daytime NO2 near the maxima of the distributions, and systematic errors are estimated to be of a similar size. However, there remains an unresolved systematic difference of about a factor of 2 between ISAMS and CLAES. Both random and systematic errors are likely to be reduced in future versions of the processing.

  19. Space Electron Density Gradient Studies using a 3D Embedded Reconfigurable Sounder and ESA/NASA CLUSTER Mission

    NASA Astrophysics Data System (ADS)

    Dekoulis, George

    2016-07-01

    This paper provides a direct comparison between data captured by a new embedded reconfigurable digital sounder, different ground-based ionospheric sounders spread around Europe and the ESA/NASA CLUSTER mission. The CLUSTER mission consists of four identical space probes flying in a formation that allows measurements of the electron density gradient in the local magnetic field. Both the ground-based and the spacecraft instrumentations assist in studying the motion, geometry and boundaries of the plasmasphere. The comparison results are in accordance to each other. Some slight deviations among the captured data were expected from the beginning of this investigation. These small discrepancies are reasonable and seriatim analyzed. The results of this research are significant, since the level of the plasma's ionization, which is related to the solar activity, dominates the propagation of electromagnetic waves through it. Similarly, unusually high solar activity presents serious hazards to orbiting satellites, spaceborne instrumentation, satellite communications and infrastructure located on the Earth's surface. Long-term collaborative study of the data is required to continue, in order to identify and determine the enhanced risk in advance. This would allow scientists to propose an immediate cure.

  20. Stratospheric CH3CN from the UARS Microwave Limb Sounder

    NASA Astrophysics Data System (ADS)

    Livesey, Nathaniel J.; Waters, Joe W.; Khosravi, Rashid; Brasseur, Guy P.; Tyndall, Geoffrey S.; Read, William G.

    CH3CN in the stratosphere has been measured by the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS), providing the first global CH3CN dataset. The MLS observations are in broad agreement with past high and midlatitude observations of CH3CN, although concentrations are a little larger than previously observed. In the tropics, where CH3CN has not up to now been measured, a persistent ‘peak’ in the profiles is seen around 22 hPa, which may be evidence of a tropical stratospheric CH3CN source. Comparisons are made with the NCAR SOCRATES model, including runs having an artificial tropical stratospheric CH3CN source.

  1. Design of a flexible and low-power ionospheric sounder

    NASA Astrophysics Data System (ADS)

    Morris, Alex

    Characterizing the structure of the ionosphere has practical applications for telecommunications and scientific applications for studies of the near-Earth space environment. Among several methods for measuring parameters of the ionosphere is ionospheric sounding, a radar technique that determines the electron content of the ionosphere as a function of height. Various research, military, and commercial institutions operate hundreds of ground-based ionosondes throughout the globe, and new ionosondes continue to be deployed in increasingly remote and distant locations. This thesis presents the design of an ionospheric sounder that reduces the power, size, and cost compared to existing systems. Key improvements include the use of an open-source software-defined radio platform and channel-aware dynamic sounding scheduling.

  2. Oblique-incidence sounder measurements with absolute propagation delay timing

    SciTech Connect

    Daehler, M.

    1990-05-03

    Timing from the Global Position Satellite (GPS) system has been applied to HF oblique incidence sounder measurements to produce ionograms whose propagation delay time scale is absolutely calibrated. Such a calibration is useful for interpreting ionograms in terms of the electron density true-height profile for the ionosphere responsible for the propagation. Use of the time variations in the shape of the electron density profile, in conjunction with an HF propagation model, is expected to provide better near-term (1-24 hour) HF propagation forecasts than are available from current updating systems, which use only the MUF. Such a capability may provide the basis for HF frequency management techniques which are more efficient than current methods. Absolute timing and other techniques applicable to automatic extraction of the electron-density profile from an ionogram will be discussed.

  3. Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

    NASA Technical Reports Server (NTRS)

    Zhu, Jiang; Stevens, E.; Zavodsky, B. T.; Zhang, X.; Heinrichs, T.; Broderson, D.

    2014-01-01

    Data assimilation has been demonstrated very useful in improving both global and regional numerical weather prediction. Alaska has very coarser surface observation sites. On the other hand, it gets much more satellite overpass than lower 48 states. How to utilize satellite data to improve numerical prediction is one of hot topics among weather forecast community in Alaska. The Geographic Information Network of Alaska (GINA) at University of Alaska is conducting study on satellite data assimilation for WRF model. AIRS/CRIS sounder profile data are used to assimilate the initial condition for the customized regional WRF model (GINA-WRF model). Normalized standard deviation, RMSE, and correlation statistic analysis methods are applied to analyze one case of 48 hours forecasts and one month of 24-hour forecasts in order to evaluate the improvement of regional numerical model from Data assimilation. The final goal of the research is to provide improved real-time short-time forecast for Alaska regions.

  4. Slow Z-mode radiation from sounder-accelerated electrons

    NASA Astrophysics Data System (ADS)

    James, H. G.

    2004-12-01

    Quasi-electrostatic Z-mode waves created by the transmitting part of the OEDIPUS-C payload were measured on the receiving part at 1200 m distance. Solutions of the complete electromagnetic dispersion relation for a hot magnetoplasma reveal, however, that there is no solution that provides direct ray paths along the transmitter-receiver separation direction with the observed signal group delays. An interpretive model is therefore proposed in which sounder-accelerated electrons (SAE) radiate incoherently as they spiral along the magnetic field direction in the general direction of the receiving subpayload. Test-particle theory combined with the hot-plasma dispersion solution is used to predict the total electric field for previously reported SAE flux levels. It is found that voltage levels measured on the receiving dipoles have about the same order of magnitude as the predicted ones.

  5. Doppler sounder observations of trade winds and sea breezes along the African west coast near 34 ° S, 19 ° E

    NASA Astrophysics Data System (ADS)

    Jury, Mark; Spencer-Smith, Garth

    1988-09-01

    Summer weather conditions along the west coast of Africa near 34 ° S, 18 ° E are investigated using doppler acoustic sounder profiles. Case studies were selected from a two-year record to form composite analyses over the diurnal cycle. The SE trade wind exhibited a low level jet at the level of the temperature inversion due to a sharp reversal in the thermal wind vector aloft. Mean wind speeds reached 14 m s-1 just before midnight as the surface and upper inversions strengthened. Seabreezes were categorised by the supporting gradient wind and found to have mean depths of 400 m, speeds of over 6 m s-1 at the 200 m level, and advance/retreat times of 09 hr and 16 20 hr. During seabreezes and weak on-shore gradient flow conditions, the thermal internal boundary layer (TIBL) was monitored with sounder transects in the first 12 km of the coastal zone. The growth height was observed to be 1:20 in the first 5 km and 1:50 farther inland. The sounder climatology, together with surface network and aerial survey results, illustrate the four-dimensional characteristics of trade winds and seabreezes near Cape Town.

  6. Infrared astronomy

    NASA Technical Reports Server (NTRS)

    Gillett, Frederick; Houck, James; Bally, John; Becklin, Eric; Brown, Robert Hamilton; Draine, Bruce; Frogel, Jay; Gatley, Ian; Gehrz, Robert; Hildebrand, Roger

    1991-01-01

    The decade of 1990's presents an opportunity to address fundamental astrophysical issues through observations at IR wavelengths made possible by technological and scientific advances during the last decade. The major elements of recommended program are: the Space Infrared Telescope Facility (SIRTF), the Stratospheric Observatory For Infrared Astronomy (SOFIA) and the IR Optimized 8-m Telescope (IRO), a detector and instrumentation program, the SubMilliMeter Mission (SMMM), the 2 Microns All Sky Survey (2MASS), a sound infrastructure, and technology development programs. Also presented are: perspective, science opportunities, technical overview, project recommendations, future directions, and infrastructure.

  7. Development and initial assessment of a new land index for microwave humidity sounder cloud detection

    NASA Astrophysics Data System (ADS)

    Qin, Zhengkun; Zou, Xiaolei

    2016-02-01

    This paper describes a new quality control (QC) scheme for microwave humidity sounder (MHS) data assimilation. It consists of a cloud detection step and an O-B (i.e., differences of brightness temperatures between observations and model simulations) check. Over ocean, cloud detection can be carried out based on two MHS window channels and two Advanced Microwave Sounding Unit-A (AMSU-A) window channels, which can be used for obtaining cloud ice water path (IWP) and liquid water path (LWP), respectively. Over land, cloud detection of microwave data becomes much more challenging due to a much larger emission contribution from land surface than that from cloud. The current MHS cloud detection over land employs an O-B based method, which could fail to identify cloudy radiances when there is mismatch between actual clouds and model clouds. In this study, a new MHS observation based index is developed for identifying MHS cloudy radiances over land. The new land index for cloud detection exploits the large variability of brightness temperature observations among MHS channels over different clouds. It is shown that those MHS cloudy radiances that were otherwise missed by the current O-B based QC method can be successfully identified by the new land index. An O-B check can then be employed to the remaining data after cloud detection to remove additional outliers with model simulations deviated greatly from observations. It is shown that MHS channel correlations are significantly reduced by the newly proposed QC scheme.

  8. THz Limb Sounder (TLS) for Lower Thermospheric Wind, Oxygen Density, and Temperature

    NASA Technical Reports Server (NTRS)

    Wu, Dong L.; Yee, Jeng-Hwa; Schlecht, Erich; Mehdi, Imran; Siles, Jose; Drouin, Brian J.

    2016-01-01

    Neutral winds are one of the most critical measurements in the lower thermosphere and E region ionosphere (LTEI) for understanding complex electrodynamic processes and ion-neutral interactions. We are developing a high-sensitivity, low-power, noncryogenic 2.06 THz Schottky receiver to measure wind profiles at 100-140 km. The new technique, THz limb sounder (TLS), aims to measure LTEI winds by resolving the wind-induced Doppler shift of 2.06 THz atomic oxygen (OI) emissions. As a transition between fine structure levels in the ground electronic state, the OI emission is in local thermodynamic equilibrium(LTE) at altitudes up to 350km. This LTE property, together with day-and-night capability and small line-of-sight gradient, makes the OI limb sounding a very attractive technique for neutral wind observations. In addition to the wind measurement, TLS can also retrieve [OI] density and neutral temperature in the LTEI region. TLS leverages rapid advances in THz receiver technologies including subharmonically pumped (SHP)mixers and Schottky-diode-based power multipliers. Current SHP Schottky receivers have produced good sensitivity for THz frequencies at ambient environment temperatures (120-150 K), which are achievable through passively cooling in spaceflight. As an emerging technique, TLS can fill the critical data gaps in the LTEI neutral wind observations to enable detailed studies on the coupling and dynamo processes between charged and neutral molecules.

  9. THz limb sounder (TLS) for lower thermospheric wind, oxygen density, and temperature

    NASA Astrophysics Data System (ADS)

    Wu, Dong L.; Yee, Jeng-Hwa; Schlecht, Erich; Mehdi, Imran; Siles, Jose; Drouin, Brian J.

    2016-07-01

    Neutral winds are one of the most critical measurements in the lower thermosphere and E region ionosphere (LTEI) for understanding complex electrodynamic processes and ion-neutral interactions. We are developing a high-sensitivity, low-power, noncryogenic 2.06 THz Schottky receiver to measure wind profiles at 100-140 km. The new technique, THz limb sounder (TLS), aims to measure LTEI winds by resolving the wind-induced Doppler shift of 2.06 THz atomic oxygen (OI) emissions. As a transition between fine structure levels in the ground electronic state, the OI emission is in local thermodynamic equilibrium (LTE) at altitudes up to 350 km. This LTE property, together with day-and-night capability and small line-of-sight gradient, makes the OI limb sounding a very attractive technique for neutral wind observations. In addition to the wind measurement, TLS can also retrieve [OI] density and neutral temperature in the LTEI region. TLS leverages rapid advances in THz receiver technologies including subharmonically pumped (SHP) mixers and Schottky-diode-based power multipliers. Current SHP Schottky receivers have produced good sensitivity for THz frequencies at ambient environment temperatures (120-150 K), which are achievable through passively cooling in spaceflight. As an emerging technique, TLS can fill the critical data gaps in the LTEI neutral wind observations to enable detailed studies on the coupling and dynamo processes between charged and neutral molecules.

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

    NASA Astrophysics Data System (ADS)

    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 (<10 kms), are required for improved forecasting of extreme weather events. We envision a suite of low-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

  11. Development of an interatmospheric window wavelength (5-9 μm) infrared thermography with an advanced image processing technique

    NASA Astrophysics Data System (ADS)

    Sato, Daisuke; Komiyama, Tatsuhito; Sakagami, Takahide; Kubo, Shiro

    2006-04-01

    Recently, deterioration of concrete structures before their design life has become a serious social problem in Japan. Nondestructive inspection techniques are required, for detecting defects and damages in concrete structures, such as subsurface void or delamination. As one of these techniques, the thermographic NDT can be applied as an effective NDT technique to inspect large area of the objective structure from distant place. In addition, it does not require any chemicals and application of physical excitation for inspection. However, the thermographic NDT has a shortcoming that the measurement results are affected by the reflection of atmospheric radiation due to the sunlight, sky or surrounding materials. Since most of the buildings in Japan are covered with luster materials with low emissivity, such as tile or mortal, infrared reflection on the surface is difficult to be neglected. To reduce the influence of these reflection noises, the infrared thermography with detectable wavelength from 5 to 8 μm, which coincides with absorption range of moisture, is utilized. In this research, a new infrared thermography with 5 to 8 μm wavelength range by applying a band pass filter and an uncooled microbolometer infrared array detector. Further, a new signal to noise (S/N) ratio improvement technique has been developed in order to compensate a deterioration of sensitivity due to the band pass filter.

  12. Intercomparison of three microwave/infrared high resolution line-by-line radiative transfer codes

    NASA Astrophysics Data System (ADS)

    Schreier, F.; Garcia, S. Gimeno; Milz, M.; Kottayil, A.; Höpfner, M.; von Clarmann, T.; Stiller, G.

    2013-05-01

    An intercomparison of three line-by-line (lbl) codes developed independently for atmospheric sounding - ARTS, GARLIC, and KOPRA - has been performed for a thermal infrared nadir sounding application assuming a HIRS-like (High resolution Infrared Radiation Sounder) setup. Radiances for the HIRS infrared channels and a set of 42 atmospheric profiles from the "Garand dataset" have been computed. Results of this intercomparison and a discussion of reasons of the observed differences are presented.

  13. GOES-R Advanced Baseline Imager: spectral response functions and radiometric biases with the NPP Visible Infrared Imaging Radiometer Suite evaluated for desert calibration sites.

    PubMed

    Pearlman, Aaron; Pogorzala, David; Cao, Changyong

    2013-11-01

    The Advanced Baseline Imager (ABI), which will be launched in late 2015 on the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite R-series satellite, will be evaluated in terms of its data quality postlaunch through comparisons with other satellite sensors such as the recently launched Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership satellite. The ABI has completed much of its prelaunch characterization and its developers have generated and released its channel spectral response functions (response versus wavelength). Using these responses and constraining a radiative transfer model with ground reflectance, aerosol, and water vapor measurements, we simulate observed top of atmosphere (TOA) reflectances for analogous visible and near infrared channels of the VIIRS and ABI sensors at the Sonoran Desert and White Sands National Monument sites and calculate the radiometric biases and their uncertainties. We also calculate sensor TOA reflectances using aircraft hyperspectral data from the Airborne Visible/Infrared Imaging Spectrometer to validate the uncertainties in several of the ABI and VIIRS channels and discuss the potential for validating the others. Once on-orbit, calibration scientists can use these biases to ensure ABI data quality and consistency to support the numerical weather prediction community and other data users. They can also use the results for ABI or VIIRS anomaly detection and resolution.

  14. Recent microwave sounder observations from aircraft during the HS3 field campaign

    NASA Astrophysics Data System (ADS)

    Lambrigtsen, B.; Brown, S. E.

    2014-12-01

    The High Altitude MMIC Sounding Radiometer (HAMSR) is a microwave sounder similar to but more capable and accurate than current satellite microwave sounders. Since 2010 it has operated on NASA's Global Hawk UAVs and has been participating in the multiyear Hurricane and Severe Storm Sentinel (HS3) hurricane campaign. We present recent results from HS3, including analysis of the thermodynamic and precipitation structure in and around tropical storm systems sampled during HS3. Copyright 2014 California Institute of Technology. Government sponsorship acknowledged.

  15. Detecting Climate Signatures with High Spectral Resolution Infrared Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Deslover, D. H.; Tobin, D.; Knuteson, R. O.; Revercomb, H. E.

    2013-12-01

    Upwelling atmospheric infrared radiances can be accurately monitored from high spectral resolution satellite observations. The high spectral resolution nature of these measurements affords the ability to track various climate relevant parameters such as window channels sensitive to surface temperature and clouds, channels with higher sensitivity to trace gases including CO2, CH4, SO2, HNO3, as well as channels sensitive only to upper tropospheric or lower stratospheric temperature. NASA's Atmospheric Infrared Sounder (AIRS) provides a data record that extends from its 2002 launch to the present. The Infrared Atmospheric Sounding Interferometer (IASI) onboard Metop- (A launched in 2006, B in 2012), as well as the Joint Polar Satellite System (JPSS) Cross-track Infrared Sounder (CrIS) launched in 2011, complement this data record. Future infrared sounders with similar capabilities will augment these measurements into the distant future. We have created a global data set from the aforementioned satellite observations. Our analysis yields a channel dependent approach that can be further constrained in terms of diurnal, seasonal and geographic limits, with measurement accuracies of better than a few tenths of degree Kelvin. In this study, we have applied this concept to obtain a better understanding of long-term stratospheric temperature trends. We will present a survey of temperature trends for spectral channels that were chosen to be sensitive to stratospheric emission. Results will be shown for tropical, mid-latitude and polar stratospheric observations.

  16. Limits of Precipitation Detection from Microwave Radiometers and Sounders

    NASA Astrophysics Data System (ADS)

    Munchak, S. J.; Skofronick-Jackson, G.; Johnson, B. T.

    2012-04-01

    The Global Precipitation Measurement (GPM) mission will unify and draw from numerous microwave conical scanning imaging radiometers and cross-track sounders, many of which already in operation, to provide near real-time precipitation estimates worldwide at 3-hour intervals. Some of these instruments were designed for primary purposes unrelated to precipitation remote sensing. Therefore it is worthwhile to evaluate the strengths and weaknesses of each set of channels with respect to precipitation detection to fully understand their role in the GPM constellation. The GPM radiometer algorithm will use an observationally-based Bayesian retrieval with common databases of precipitation profiles for all sensors. Since these databases are still under development and will not be truly complete until the GPM core satellite has completed at least one year of dual-frequency radar observations, a screening method based upon retrieval of non-precipitation parameters related to the surface and atmospheric state is used in this study. A cost function representing the departure of modeled radiances from their observed values plus the departure of surface and atmospheric parameters from the TELSEM emissivity atlas and MERRA reanalysis is used as an indicator of precipitation. Using this method, two datasets are used to evaluate precipitation detection: One year of matched AMSR-E and AMSU-B/MHS overpasses with CloudSat used as validation globally; and SSMIS overpasses over the United States using the National Mosaic and QPE (NMQ) as validation. The Heidke Skill Score (HSS) is used as a metric to evaluate detection skill over different surfaces, seasons, and across different sensors. Non-frozen oceans give the highest HSS for all sensors, followed by bare land and coasts, then snow-covered land and sea ice. Negligible skill is present over ice sheets. Sounders tend to have higher skill than imagers over complex surfaces (coast, snow, and sea ice), whereas imagers have higher skill

  17. Global measurements of wind fields using the Laser Atmospheric Wind Sounder (LAWS) on the Earth Observing System (EOS)

    NASA Technical Reports Server (NTRS)

    Fitzjarrald, Daniel E.

    1988-01-01

    The technology for measuring global wind fields in space by the Laser Atmospheric Wind Sounder (LAWS) to be flown on the Earth Observing System (EOS) is discussed. Studies initiated by NASA to determine the feasibility of using Doppler lidar from a platform in space to measure the wind globally have shown the general feasibility of the technique and have identified the technological problems that need to be resolved. Among the lidar systems being evaluated, CO2 coherent detection lidar is given special consideration. A comprehensive research program, the Global Backscatter Experiment, has been established to study global distribution of naturally occurring atmospheric aerosols that provide signal return at the wavelengths used by the techniques under consideration. Wind profiles from space will provide essential information for advancing the skill of numerical weather prediction, furthering the present knowledge of the large-scale atmospheric circulation and climate dynamics, and of global biogeochemical and hydrologic cycles.

  18. Real-time Data Processing and Visualization for the Airborne Scanning High-resolution Interferometer Sounder (S-HIS)

    NASA Astrophysics Data System (ADS)

    Taylor, J. K.; Revercomb, H. E.; Hoese, D.; Garcia, R. K.; Smith, W. L.; Weisz, E.; Tobin, D. C.; Best, F. A.; Knuteson, R. O.; Sullivan, D. V.; Barnes, C. M.; Van Gilst, D. P.

    2015-12-01

    The Hurricane and Severe Storm Sentinel (HS3) is a five-year NASA mission targeted to enhance the understanding of the formation and evolution of hurricanes in the Atlantic basin. Measurements were made from two NASA Global Hawk Unmanned Aircraft Systems (UAS) during the 2012 through 2014 hurricane seasons, with flights conducted from the NASA Wallops Flight Facility. The Global Hawk aircraft are capable of high altitude flights with durations of up to 30 hours, which allow extensive observations over distant storms, not typically possible with manned aircraft. The two NASA Global Hawks were equipped with instrument suites to study the storm environment, and inner core structure and processes, respectively. The Scanning High-resolution Interferometer Sounder (S-HIS), designed and built by the University of Wisconsin (UW) Space Science and Engineering Center (SSEC), measures emitted thermal radiation at high spectral resolution between 3.3 and 18 microns. The radiance measurements are used to obtain temperature and water vapor profiles of the Earth's atmosphere. The S-HIS spatial resolution is 2 km at nadir, across a 40 km ground swath from a nominal altitude of 20 kilometers. Since 1998, the S-HIS has participated in 33 field campaigns and has proven to be extremely dependable, effective, and highly accurate. It has flown on the NASA ER-2, DC-8, Proteus, WB-57, and Global Hawk airborne platforms. The UW S-HIS infrared sounder instrument is equipped with a real-time ground data processing system capable of delivering atmospheric profiles, radiance data, and engineering status to mission support scientists - all within less than one minute from the time of observation. This ground data processing system was assembled by a small team using existing software and proven practical techniques similar to a satellite ground system architecture. This summary outlines the design overview for the system and illustrates the data path, content, and outcomes.

  19. Mars Climate Sounder observations in support of the Mars Science Laboratory Landing

    NASA Astrophysics Data System (ADS)

    Kass, D. M.; Vasavada, A. R.; Kleinboehl, A.; Schofield, J. T.; Mischna, M. A.; McCleese, D. J.

    2012-12-01

    The Mars Climate Sounder (MCS) is a 9-channel mid- and far infrared limb and on-planet viewing radiometer. Its limb radiance profile measurements are inverted to retrieve temperature, dust and ice extinction profiles. MCS is on the Mars Reconnaissance Orbiter (MRO) spacecraft, in a sun-synchronous polar orbit. As the Mars Science Laboratory (MSL) approached Mars and prepared to land on August 6th, MCS provided daily observations of the martian weather close to Gale crater, MSL's landing site. These were compared to the previous years of MCS observations that had already been used to validate the thermal structure and aerosol distributions in the mesoscale models that are used in MSL entry, descent, and landing (EDL) Monte Carlo simulations. The comparisons allowed the MSL team to optimize the lander's systems for the predicted weather during EDL. In addition, the MRO orbit provides MCS with global coverage of the martian atmosphere on a daily basis. Here we give an overview on the martian weather conditions prior to MSL landing. The weather was dominated by the activity along the southern seasonal polar cap edge supported/driven by a number baroclinic features associated with the southern winter polar vortex. Throughout the two months preceding EDL, the MCS observations were compared to the three previous Mars years where MCS observed the atmosphere at the mid-northern summer season (Ls 150) when EDL occurred. While several of the years are quite similar with a cold, cloudy aphelion season there is significant interannual variability. In addition, during this period, the atmosphere undergoes a number of seasonal transitions as the solsticial circulation realigns to the equinoctial circulation.

  20. Temperature and dust profiles in Martian dust storm conditions retrieved from Mars Climate Sounder measurements

    NASA Astrophysics Data System (ADS)

    Kleinboehl, A.; Kass, D. M.; Schofield, J. T.; McCleese, D. J.

    2013-12-01

    Mars Climate Sounder (MCS) is a mid- and far-infrared thermal emission radiometer on board the Mars Reconnaissance Orbiter. It measures radiances in limb and nadir/on-planet geometry from which vertical profiles of atmospheric temperature, water vapor, dust and condensates can be retrieved in an altitude range from 0 to 80 km and with a vertical resolution of ~5 km. Due to the limb geometry used as the MCS primary observation mode, retrievals in conditions with high aerosol loading are challenging. We have developed several modifications to the MCS retrieval algorithm that will facilitate profile retrievals in high-dust conditions. Key modifications include a retrieval option that uses a surface pressure climatology if a pressure retrieval is not possible in high dust conditions, an extension of aerosol retrievals to higher altitudes, and a correction to the surface temperature climatology. In conditions of a global dust storm, surface temperatures tend to be lower compared to standard conditions. Taking this into account using an adaptive value based on atmospheric opacity leads to improved fits to the radiances measured by MCS and improves the retrieval success rate. We present first results of these improved retrievals during the global dust storm in 2007. Based on the limb opacities observed during the storm, retrievals are typically possible above ~30 km altitude. Temperatures around 240 K are observed in the middle atmosphere at mid- and high southern latitudes after the onset of the storm. Dust appears to be nearly homogeneously mixed at lower altitudes. Significant dust opacities are detected at least up to 70 km altitude. During much of the storm, in particular at higher altitudes, the retrieved dust profiles closely resemble a Conrath-profile.

  1. Sensitivity Studies for a Space-based CO2 Laser Sounder

    NASA Astrophysics Data System (ADS)

    Mao, J.; Kawa, S. R.; Abshire, J. B.; Riris, H.

    2007-12-01

    NASA is developing a space-based CO2 Laser Sounder at Goddard Space Flight Center that is aimed at providing global CO2 measurement in the troposphere with an ultimate measurement precision goal of less than 1%. The laser technique uses a CO2 absorption band in the near infrared and has a number of laser wavelengths across one strong absorption line centered at 1572 nm. The focus of the laser measurement is lower atmosphere CO2. The lasers are pulsed and the surface return signal can be well separated from that returned by the atmosphere using time gating in the receiver. Atmospheric scattering effects on the returned signals can be greatly reduced by this method. In this paper, we report our line-by-line radiative transfer calculation results for the selection of laser frequencies used in this active technique, including the optimal selection of absorption line and laser frequencies at which the sensitivity to atmospheric temperatures is minimal and response to lower atmospheric CO2 is maximal. Other effects on this measurement, e.g., water vapor as the most variable atmospheric composition, will be also analyzed. In addition, the simultaneous measurement of surface pressure is fundamentally required in order to appropriately estimate the change of CO2 absorption corresponding to pressure fluctuation, to compute the CO2 mixing ratio relative to dry air, and to separate actual CO2 surface flux from variations in atmospheric density. The measurement technique for surface pressure will be similar to that for CO2 but uses the O2 A-band near 768 nm. Radiative transfer calculations for the surface pressure measurement will be also reported. Other information (e.g., temperature and water vapor estimates) required to go from differential absorption measurements to final CO2 concentration retrievals will be assessed and discussed.

  2. Microwave Limb Sounder/El Nino Watch - December, 1997

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This image shows differences in atmospheric water vapor relative to a normal (average) year in the Earth's upper troposphere about 10 kilometers (6 miles) above the surface. The measurements were taken by the Microwave Limb Sounder (MLS) instrument aboard NASA's Upper Atmosphere Research Satellite (UARS). These data, collected in late December 1997, show higher than normal levels of water vapor (red) over the central and eastern Pacific which indicates the presence of an El Nino condition. At the same time, the western Pacific (blue) is much drier than normal. The unusually moist air above the central and eastern Pacific is a consequence of the much warmer-than-normal ocean waters which occur during El Nino. Warmer water evaporates at a higher rate and the resulting warm moist air rises and forms tall cloud towers. In the tropics, the warm water and the resulting tall cloud towers typically produce large amounts of rain. These data show significant increases in the amount of atmospheric moisture off the coast of Peru and Ecuador since measurements were made in November 1997. The maximum water temperature in the eastern tropical Pacific, as measured by the National Oceanic and Atmospheric Administration (NOAA), is still higher than normal and these high ocean temperatures are likely responsible for an increase in evaporation and the subsequent rise in humidity.

  3. The WHISPER Relaxation Sounder and the CLUSTER Active Archive

    NASA Astrophysics Data System (ADS)

    Trotignon, J. G.; Décréau, P. M. E.; Rauch, J. L.; Vallières, X.; Rochel, A.; Kougblénou, S.; Lointier, G.; Facskó, G.; Canu, P.; Darrouzet, F.; Masson, A.

    The Waves of HIgh frequency and Sounder for Probing of Electron density by Relaxation (WHISPER) instrument is part of the Wave Experiment Consortium (WEC) of the CLUSTER mission. With the help of the long double sphere antennae of the Electric Field and Wave (EFW) instrument and the Digital Wave Processor (DWP), it delivers active (sounding) and natural (transmitter off) electric field spectra, respectively from 4 to 82 kHz, and from 2 to 80 kHz. These frequency ranges have been chosen to include the electron plasma frequency, which is closely related to the total electron density, in most of the regions encountered by the CLUSTER spacecraft. Presented here is an overview of the WHISPER data products available in the CLUSTER Active Archive (CAA). The instrument and its performance are first recalled. The way the WHISPER products are obtained is then described, with particular attention being paid to the density determination. Both sounding and natural measurements are commonly used in this process, which depends on the ambient plasma regime. This is illustrated using drawings similar to the Bryant plots commonly used in the CLUSTER master science plan. These give a clear overview of typical density values and the parts of the orbits where they are obtained. More information on the applied software or on the quality/reliability of the density determination can also be highlighted.

  4. Scanning Mechanism of the FY-3 Microwave Humidity Sounder

    NASA Technical Reports Server (NTRS)

    Schmid, Manfred; Jing, Li; Hehr, Christian

    2010-01-01

    Astrium GmbH Germany, developed the scanning equipment for the instrument package of the MicroWave Humidity Sounder (MWHS) flying on the FY-3 meteorological satellite (FY means Feng Yun, Wind and Cloud) in a sun-synchronized orbit of 850-km altitude and at an inclination of 98.8 . The scanning mechanism rotates at variable velocity comprising several acceleration / deceleration phases during each revolution. The Scanning Mechanism contains two output shafts, each rotating a parabolic offset Antenna Reflector. The mechanism is operated in closed loop by means of redundant control electronics. MWHS is a sounding radiometer for measurement of global atmospheric water vapour profiles. An Engineering Qualification Model was developed and qualified and a first Flight Model was launched early 2008. The system is now working for more than two years successful in orbit. A second Flight Model of the Antenna Scanning Mechanism and of its associated control electronics was built and delivered to the customer for application on the follow-on spacecraft that will be launched by the end of 2010.

  5. The Mars Climate Sounder In-Flight Positioning Anomaly

    NASA Technical Reports Server (NTRS)

    Jau, Bruno M.; Kass, David

    2008-01-01

    The paper discusses the Mars Climate Sounder (MCS) instrument s in-flight positioning errors and presents background material about it. A short overview of the instrument s science objectives and data acquisition techniques is provided. The brief mechanical description familiarizes the reader with the MCS instrument. Several key items of the flight qualification program, which had a rigorous joint drive test program but some limitations in overall system testing, are discussed. Implications this might have had for the flight anomaly, which began after several months of flawless space operation, are mentioned. The detection, interpretation, and instrument response to the errors is discussed. The anomaly prompted engineering reviews, renewed ground, and some in-flight testing. A summary of these events, including a timeline, is included. Several items of concern were uncovered during the anomaly investigation, the root cause, however, was never found. The instrument is now used with two operational constraints that work around the anomaly. It continues science gathering at an only slightly diminished pace that will yield approximately 90% of the originally intended science.

  6. Application of VISSR Atmospheric Sounder (VAS) data in weather analysis

    NASA Technical Reports Server (NTRS)

    Jedlovec, G. J.

    1984-01-01

    A technique which analyzes irregularly spaced satellite data is described. An experiment with rawinsonde and VISSR Atmospheric Sounder (VAS) radiance measurements collected on March 6-7, 1982 is conducted to reveal the applicability of the technique. The rawinsonde data are analyzed on a 16 x 12 grid using the two pass analysis scheme of Barnes (1973). A scheme similar to the Barnes (1973) procedure is employed to produce gridded analysis of VAS data over a 200 x 15000 km region in central part of the U.S. The use of a correction pass on the initial gridded field is described; the technique is extremely effective on uniformly spaced observations. The incorporation of the limited fine mesh model to the scheme to analyze data in sparse and cloudy regions is examined. A comparison of rawinsonde data with VAS data is provided. The technique proves effective for studying cloudy and sparse areas with VAS data and produces a four-dimensional data set with significant mesoscale structure.

  7. The Upper Atmosphere Research Satellite microwave limb sounder instrument

    NASA Technical Reports Server (NTRS)

    Barath, F. T.; Chavez, M. C.; Cofield, R. E.; Flower, D. A.; Frerking, M. A.; Gram, M. B.; Harris, W. M.; Holden, J. R.; Jarnot, R. F.; Kloezeman, W. G.

    1993-01-01

    The microwave limb sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) is the first satellite experiment using limb sounding techniques at microwave frequencies. Primary measurement objectives are stratospheric ClO, O3, H2O, temperature, and pressure. Measurements are of thermal emission: all are performed simultaneously and continuously and are not degraded by ice clouds or volcanic aerosols. The instrument has a 1.6-m mechanically scanning antenna system and contains heterodyne radiometers in spectral bands centred near 63, 183, and 205 GHz. The radiometers operate at ambient temperature and use Schottky-diode mixers with local oscillators derived from phase-locked Gunn oscillators. Frequency tripling by varactor multipliers generates the 183- and 205-GHz local oscillators, and quasi-optical techniques inject these into the mixers. Six 15-channel filter banks spectrally resolve stratospheric thermal emission lines and produce an output spectrum every 2 s. Thermal stability is sufficient for 'total power' measurements which do not require fast chopping. Radiometric calibration, consisting of measurements of cold space and an internal target, is performed every 65-s limb scan. Instrument in-orbit performance has been excellent, and all objectives are being met.

  8. Wavelet-based coding of ultraspectral sounder data

    NASA Astrophysics Data System (ADS)

    Garcia-Vilchez, Fernando; Serra-Sagrista, Joan; Auli-Llinas, Francesc

    2005-08-01

    In this paper we provide a study concerning the suitability of well-known image coding techniques originally devised for lossy compression of still natural images when applied to lossless compression of ultraspectral sounder data. We present here the experimental results of six wavelet-based widespread coding techniques, namely EZW, IC, SPIHT, JPEG2000, SPECK and CCSDS-IDC. Since the considered techniques are 2-dimensional (2D) in nature but the ultraspectral data are 3D, a pre-processing stage is applied to convert the two spatial dimensions into a single spatial dimension. All the wavelet-based techniques are competitive when compared either to the benchmark prediction-based methods for lossless compression, CALIC and JPEG-LS, or to two common compression utilities, GZIP and BZIP2. EZW, SPIHT, SPECK and CCSDS-IDC provide a very similar performance, while IC and JPEG2000 improve the compression factor when compared to the other wavelet-based methods. Nevertheless, they are not competitive when compared to a fast precomputed vector quantizer. The benefits of applying a pre-processing stage, the Bias Adjusted Reordering, prior to the coding process in order to further exploit the spectral and/or spatial correlation when 2D techniques are employed, are also presented.

  9. Validation of UARS Microwave Limb Sounder ClO Measurements

    NASA Technical Reports Server (NTRS)

    Waters, J. W.; Read, W. G.; Froidevaux, L.; Lungu, T. A.; Perun, V. S.; Stachnik, R. A.; Jarnot, R. F.; Cofield, R. E.; Fishbein, E. F.; Flower, D. A.; Burke, J. R.; Hardy, J. C.; Nakamura, L. L.; Ridenoure, B. P.; Shippony, Z.; Thurstans, R. P.; Thurstans, R. P.; Avallone, L. M.; Toohey, D. W.; deZafra, R. L.; Shindell, D. T.

    1996-01-01

    Validation of stratospheric ClO measurements by the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) is described. Credibility of the measurements is established by (1) the consistency of the measured ClO spectral emission line with the retrieved ClO profiles and (2) comparisons of ClO from MLS with that from correlative measurements by balloon-based, ground-based, and aircraft-based instruments. Values of "noise" (random), "scaling" (multiplicative), and "bias" (additive) uncertainties are determined for the Version 3 data, in the first version public release of the known artifacts in these data are identified. Comparisons with correlative measurements indicate agreement to within the combined uncertainties expected for MLS and the other measurements being compared. It is concluded that MLS Version 3 ClO data, with proper consideration of the uncertainties and "quality" parameters produced with these data, can be used for scientific analyses at retrieval surfaces between 46 and 1 hPa (approximately 20-50 km in height). Future work is planned to correct known problems in the data and improve their quality.

  10. A method to derive downwelling longwave fluxes at the Arctic surface from TIROS operational vertical sounder data

    NASA Astrophysics Data System (ADS)

    Francis, Jennifer A.

    1997-01-01

    The dominant component of the polar surface energy budget during half the year is the downwelling flux of longwave radiation (DLF), yet little is known about its spatial and temporal variability except on monthly timescales. As surface measurements will always be sparse, the most promising opportunity for diagnosing the DLF is provided by satellite data. Estimating this flux from space, however, presents challenges over all surface types and particularly in polar environments where cloud detection and cloud fraction estimation are less certain. A new method is presented to estimate DLF from measurements by the TIROS-N operational vertical sounder (TOVS). Temperature profiles, humidity estimates, and cloud cover are retrieved from TOVS radiances using the improved initialization inversion algorithm, which has been modified to produce more accurate results over snow and sea ice. This information is combined with brightness temperature differences from pairs of infrared and near-infrared TOVS channels. These differences are used to infer cloud phase and geometric thickness. Longwave fluxes are then calculated using a forward radiative transfer model. Results during winter 1988 and spring 1992 are compared with hourly radiation measurements from the Coordinated Eastern Arctic Experiment in the eastern Arctic basin and from the Lead Experiment in the Beaufort Sea. Error analyses yield a bias of approximately 3 W m-2, a standard deviation of 23 W m-2, and a correlation coefficient of about 0.75. These errors are comparable to results from similar studies over midlatitude land and ocean areas where clouds are more easily identified.

  11. Synchrotron infrared imaging of advanced glycation endproducts (AGEs) in cardiac tissue from mice fed high glycemic diets

    PubMed Central

    Birarda, Giovanni; Holman, Elizabeth A.; Fu, Shang; Weikel, Karen; Hu, Ping; Blankenberg, Francis G.; Holman, Hoi-Ying; Taylor, Allen

    2015-01-01

    Recent research findings correlate an increased risk for dieases such as diabetes, macular degeneration and cardiovascular disease (CVD) with diets that rapidly raise the blood sugar levels; these diets are known as high glycemic index (GI) diets which include white breads, sodas and sweet deserts. Lower glycemia diets are usually rich in fruits, non-starchy vegetables and whole grain products. The goal of our study was to compare and contrast the effects of a low vs. high glycemic diet using the biochemical composition and microstructure of the heart. The improved spatial resolution and signal-to-noise for SR-FTIR obtained through the coupling of the bright synchrotron infrared photon source to an infrared spectral microscope enabled the molecular-level observation of diet-related changes within unfixed fresh frozen histologic sections of mouse cardiac tissue. High and low glycemic index (GI) diets were started at the age of five-months and continued for one year, with the diets only differing in their starch distribution (high GI diet = 100% amylopectin versus low GI diet = 30% amylopectin/70% amylose). Serial cryosections of cardiac tissue for SR-FTIR imaging alternated with adjacent hematoxylin and eosin (H&E) stained sections allowed not only fine-scale chemical analyses of glycogen and glycolipid accumulation along a vein as well as protein glycation hotspots co-localizing with collagen cold spots but also the tracking of morphological differences occurring in tandem with these chemical changes. As a result of the bright synchrotron infrared photon source coupling, we were able to provide significant molecular evidence for a positive correlation between protein glycation and collagen degradation in our mouse model. Our results bring a new insight not only to the effects of long-term GI dietary practices of the public but also to the molecular and chemical foundation behind the cardiovascular disease pathogenesis commonly seen in diabetic patients. PMID

  12. Synchrotron infrared imaging of advanced glycation endproducts (AGEs) in cardiac tissue from mice fed high glycemic diets.

    PubMed

    Birarda, Giovanni; Holman, Elizabeth A; Fu, Shang; Weikel, Karen; Hu, Ping; Blankenberg, Francis G; Holman, Hoi-Ying; Taylor, Allen

    Recent research findings correlate an increased risk for dieases such as diabetes, macular degeneration and cardiovascular disease (CVD) with diets that rapidly raise the blood sugar levels; these diets are known as high glycemic index (GI) diets which include white breads, sodas and sweet deserts. Lower glycemia diets are usually rich in fruits, non-starchy vegetables and whole grain products. The goal of our study was to compare and contrast the effects of a low vs. high glycemic diet using the biochemical composition and microstructure of the heart. The improved spatial resolution and signal-to-noise for SR-FTIR obtained through the coupling of the bright synchrotron infrared photon source to an infrared spectral microscope enabled the molecular-level observation of diet-related changes within unfixed fresh frozen histologic sections of mouse cardiac tissue. High and low glycemic index (GI) diets were started at the age of five-months and continued for one year, with the diets only differing in their starch distribution (high GI diet = 100% amylopectin versus low GI diet = 30% amylopectin/70% amylose). Serial cryosections of cardiac tissue for SR-FTIR imaging alternated with adjacent hematoxylin and eosin (H&E) stained sections allowed not only fine-scale chemical analyses of glycogen and glycolipid accumulation along a vein as well as protein glycation hotspots co-localizing with collagen cold spots but also the tracking of morphological differences occurring in tandem with these chemical changes. As a result of the bright synchrotron infrared photon source coupling, we were able to provide significant molecular evidence for a positive correlation between protein glycation and collagen degradation in our mouse model. Our results bring a new insight not only to the effects of long-term GI dietary practices of the public but also to the molecular and chemical foundation behind the cardiovascular disease pathogenesis commonly seen in diabetic patients.

  13. Operational readiness for the Atmospheric Infrared Sounder (AIRS) on the earth observing system aqua spacecraft

    NASA Technical Reports Server (NTRS)

    Pagano, T.; Aumann, H.; Chahine, M.; Karnik, A.; Goodson, G.; Schindler, R.; Elliot, D. A.; Hofstadter, M.

    2001-01-01

    This paper describes the AIRS science objectives, the instrument design and operation, the in-flight operational scenario, and the calibration plan. All aspects of the program are addressed here to demonstrate that the AIRS program is ready to transition to the flight segment of the program.

  14. Relationship between Ice Cloud Microphysics and Supersaturation from Spaceborne Cloud Radar, Lidar and Infrared Sounder

    NASA Astrophysics Data System (ADS)

    Tanaka, K.; Okamoto, H.; Sato, K.; Ishimoto, H.

    2014-12-01

    We examined the relationship between ice cloud microphysics retrieved from cloud radar on CloudSat and CALIOP on CALIPSO and super saturation inferred from AIRS on AQUA. Ice microphysics such as ice water content (IWC) and effective radius was estimated by CloudSat and CALIPSO data. Unique features of the algorithm is that it has been designed to use depolarization ratio from CALIOP addition to radar reflectivity factor from CloudSat and attenuated backscattering coefficient from CALIOP in order to take into account the variation of ice particle shapes and their orientations [Okamoto et al., 2010]. Water vapor density and temperature were retrieved with much finer resolution by the application of Ishimoto's algorithm [2009] compared with standard AIRS products where horizontal resolution is 45km. The algorithm allows retrievals of water vapor density and temperature every 13.5km in horizontal direction with 1km in vertical. The retrievals are carried out when there is no cloud with its cloud top pressure <200hPa. That is, it is possible to report water vapor information above low-level clouds. Then we sampled the amount of water vapor and temperature estimated from AIRS data to match the CloudSat and CALIPSO foot-print and the data were interpolated to have the same space and time resolution of the merged data sets of CloudSat and CALIPSO, i.e., 1.1km and 240m for horizontal and vertical resolutions. In the new AIRS products, ice super saturation often reached 150% while standard AIRS products showed less frequent super saturation. The ECMWF results generally showed smaller fraction of ice super saturation compared with the new AIRS products. In order to quantitatively compare the water vapor amount and retrieved IWC, we estimated the excess of water amount respect to ice saturation by using ice super saturation. The occurrences of ice clouds inferred from CloudSat and CALIOP agreed with the occurrences of ice-supersaturation reported in the new AIRS products. The retrieved IWC were smaller compared with the estimated IWC from the new AIRS products. Similar analyses with ECMWF showed smaller estimated IWC compared with the values in the new products.

  15. High resolution infrared radiation sounder for the Nimbus F spacecraft. [design and fabrication of protoflight unit

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1973-01-01

    The activities on the HIRS program are described for the period of July through September, 1973. Completion of design activity and early fabrication effort on the protoflight unit were the major efforts. Operation of the engineering model in spacecraft integration tests was completed during July and August, after which the unit was returned for added test and evaluation.

  16. An Anomaly Correlation Skill Score for the Evaluation of the Performance of Hyperspectral Infrared Sounders

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Manning, Evan; Barnet, Chris; Maddy, Eric; Blackwell, William

    2009-01-01

    With the availability of very accurate forecasts, the metric of accuracy alone for the evaluation of the performance of a retrieval system can produce misleading results. A useful characterization of the quality of a retrieval system and its potential to contribute to an improved weather forecast is its skill, which we define as the ability to make retrievals of geophysical parameters which are closer to the truth than the six hour forecast, when the truth differs significantly from the forecast. We illustrate retrieval skill using one day of AMSU and AIRS data with three different retrieval algorithms, which result in retrievals for more than 90% of the potential retrievals under clear and cloudy conditions. Two of the three algorithms have better than 1 K rms "RAOB quality" accuracy on the troposphere, but only one has skill between 900 and 100 mb. AIRS was launched on the EOS Aqua spacecraft in May 2002 into a 705 km polar sun-synchronous orbit with accurately maintained 1:30 PM ascending node. Essentially uninterrupted data are freely available since September 2002.

  17. The Atmospheric Infrared Sounder (AIRS) on Aqua: instrument stability and data products for climate observations

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, M.; Aumann, H.; Strow, L.; Broberg, S.; Gaiser, S.

    2003-01-01

    30th International Symposium on Remote Sensing of the Environment (ISRSE) NASA Honolulu, Hawaii, USAThis paper discusses the stability of the AIRS instrument as measured pre-flight and in-orbit. In order differentiate instrument related changes with true changes in climate observations, the instrument stability must be demonstrated.

  18. P.88 Regional Precipitation Forecast with Atmospheric Infrared Sounder (AIRS) Profiles

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Bradley; Jedlovec, Gary

    2010-01-01

    Prudent assimulation of AIRS thermodynamic profiles and quality indicators can improve initial conditions for regional weather models. In general, AIRS-enhanced analysis more closely resembles radiosondes than the CNTL; forecasts with AIRS profiles are generally closer to NAM analyses than CNTL for sensible weather parameters (not shown here). Assimilation of AIRS leads to an overall QPF improvement in 6-h accumulated precipitation forecases. Including AIRS profiles in assimilation process enhances the low-level instability and produces stronger updrafts and a better precipitation forecast than the CNTL run.

  19. P161 Improved Impact of Atmospheric Infrared Sounder (AIRS) Radiance Assimilation in Numerical Weather Prediction

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley T.; Chou, Shih-Hung; Jedlovec, Gary J.

    2012-01-01

    For over 6 years, AIRS radiances have been assimilated operationally into National (e.g. Environmental Modeling Center (EMC)) and International (e.g. European Centre for Medium-Range Weather Forecasts (ECMWF)), operational centers; assimilated in the North American Mesoscale (NAM) since 2008. Due partly to data latency and operational constraints, hyperspectral radiance assimilation has had less impact on the Gridpoint Statistical Interpolation (GSI) system used in the NAM and GFS. Objective of this project is to use AIRS retrieved profiles as a proxy for the AIRS radiances in situations where AIRS radiances are unable to be assimilated in the current operational system by evaluating location and magnitude of analysis increments.

  20. Studies based on global subsurface radar sounding of the Moon by SELENE (Kaguya) Lunar Radar Sounder (LRS): A summary

    NASA Astrophysics Data System (ADS)

    Kumamoto, A.; Yamaguchi, Y.; Yamaji, A.; Kobayashi, T.; Oshigami, S.; Ishiyama, K.; Nakamura, N.; Goto, Y.

    2015-12-01

    The Lunar Radar Sounder (LRS) onboard the SELENE (Kaguya) spacecraft has successfully performed radar sounder observations of the lunar subsurface structures and passive observations of natural radio and plasma waves from the lunar orbit. After the transfer of the spacecraft into the final lunar orbit and antenna deployment, the operation of LRS started on October 29, 2007. Through the operation until June 10, 2009, 130 million pulses worth of radar sounder data have been obtained [Ono et al., 2010]. Based on the datasets of the first lunar global subsurface radar sounding, Ono et al. [2009] revealed that there are distinct reflectors at a depth of several hundred meters in the nearside maria, which are inferred to be buried regolith layers covered by a basalt layer with a thickness of several hundred meters. Based on the further survey, Pommerol et al. [2010] pointed out the negative correlation of clear subsurface echoes with the maps of ilmenite, and suggested that dense ilmenite attenuates the radar pulse in the basaltic mare lava, and cause the absence of the clear subsurface echoes. That also suggests there are undetected subsurface reflectors especially below the young lava flow units with high ilmenite abundance. Kobayashi et al. [2012] applied synthetic aperture radar (SAR) processing to SELENE LRS data in order to obtain distinct radargram. Taking advantage of analyzing waveform data sent via high data rate telemetry from the Moon, we can perform advanced data analyses on the ground. We started providing the both SAR processed and waveform datasets via SELENE Data Archive (http://l2db.selene.darts.isas.jaxa.jp/index.html.en) since 2015. Oshigami et al. [2014] estimated volumes of basalt units in the ages of 2.7 Ga to 3.8 Ga in the nearside maria. The volume was derived from the depth of subsurface reflectors measured by LRS. The volumes of the geologic units were 103 to 104 km3. The average eruption rates were 10-5 to 10-3 km3 yr-1. The estimated volumes

  1. Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 2

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This report summarizes and documents the results of the 12-month phase 1 work effort. The objective of phase 1 was to establish the conceptional definition of the laser atmospheric wind sounder (LAWS) sensor system, including accommodations analyses to ensure compatibility with the Space Station Freedom (SSF) and the Earth Observing System (EOS) Polar Orbiting Platform (POP). Various concepts were investigated with trade studies performed to select the configuration to be carried forward to the phase 2 Preliminary Design Definition. A summary of the LAWS system and subsystem trade studies that were performed leading to the baseline design configuration is presented in the appendix. The overall objective of the LAWS Project is to define, design, and implement an operational space based facility, LAWS, for accurate measurement of Earth wind profiles. Phase 1 addressed three major areas: (1) requirements definition; (2) instrument concepts and configurations; and (3) performance analysis. For the LAWS instrument concepts and configurations, the issues which press the technological state of the art are reliable detector lifetime and laser performance and lifetime. Lag angle compensation, pointing accuracy, satellite navigation, and telescope design are significant technical issues, but they are considered to be currently state of the art. The primary issues for performance analysis concern interaction with the atmosphere in terms of backscatter and attenuation, wind variance, and cloud blockage. The phase 1 tasks were formulated to address these significant technical issues and demonstrate the technical feasibility of the LAWS concept. Primary emphasis was placed on analysis/trade and identification of candidate concepts. Promising configurations were evaluated for performance, sensitivities, risks, and budgetary costs. Lockheed's baseline LAWS configuration is presented.

  2. Validation of Aura Microwave Limb Sounder HCl Measurements

    NASA Technical Reports Server (NTRS)

    Froidevaux, L.; Jiang, Y. B.; Lambert, A.; Livesey, N. J.; Read, W. G.; Waters, J. W.; Fuller, R. A.; Marcy, T. P.; Popp, P. J.; Gao, R. S.; Fahey, D. W.; Jucks, K. W.; Stachnik, R. A.; Toon, G. C.; Christensen, L. E.; Webster, C. R.; Bernath, P. F.; Boone, C. D.; Walker, K. A.; Pumphrey, H. C.; Harwood, R. S.; Manney, G. L.; Schwartz, M. J.; Daffer, W. H.; Drouin, B. J.

    2008-01-01

    The Earth Observing System (EOS) Microwave Limb Sounder (MLS) aboard the Aura satellite has provided daily global HCl profiles since August 2004. We provide a characterization of the resolution, random and systematic uncertainties, and known issues for the version 2.2 MLS HCl data. The MLS sampling allows for comparisons with many (1500 to more than 3000) closely matched profiles from the Halogen Occultation Experiment (HALOE) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). These data sets provide HCl latitudinal distributions that are, overall, very similar to those from (coincident) MLS profiles, although there are some discrepancies in the upper stratosphere between the MLS and HALOE gradients. As found in previous work, MLS and ACE HCl profiles agree very well (within approximately 5%, on average), but the MLS HCl abundances are generally larger (by 10-20%) than HALOE HCl. The bias versus HALOE is unlikely to arise mostly from MLS, as a similar systematic bias (of order 15%) is not observed between average MLS and balloon-borne measurements of HCl, obtained over Fort Sumner, New Mexico, in 2004 and 2005. At the largest pressure (147 hPa) for MLS HCl, a high bias (approximately 0.2 ppbv) is apparent in analyses of low to midlatitude data versus in situ aircraft chemical ionization mass spectrometry (CIMS) HCl measurements from the Aura Validation Experiment (AVE) campaigns in 2004, 2005, and 2006; this bias is also observed in comparisons of MLS and aircraftHCl/O3 correlations. Good agreement between MLS and CIMS HCl is obtained at 100 to 68 hPa. The recommended pressure range for MLS HCl is from 100 to 0.15 hPa.

  3. Validation of UARS Microwave Limb Sounder Temperature and Pressure Measurements

    NASA Technical Reports Server (NTRS)

    Fishbein, E. F.; Cofield, R. E.; Froidevaux, L.; Jarnot, R. F.; Lungu, T.; Read, W. G.; Shippony, Z.; Waters, J. W.; McDermid, I. S.; McGee, T. J.; Singh, U.; Gross, M.; Hauchecorne, A.; Keckhut, P.; Gelman, M. E.; Nagatani, R. M.

    1996-01-01

    The accuracy and precision of the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) atmospheric temperature and tangent-point pressure measurements are described. Temperatures and tangent- point pressure (atmospheric pressure at the tangent height of the field of view boresight) are retrieved from a 15-channel 63-GHz radiometer measuring O2 microwave emissions from the stratosphere and mesosphere. The Version 3 data (first public release) contains scientifically useful temperatures from 22 to 0.46 hPa. Accuracy estimates are based on instrument performance, spectroscopic uncertainty and retrieval numerics, and range from 2.1 K at 22 hPa to 4.8 K at 0.46 hPa for temperature and from 200 m (equivalent log pressure) at 10 hPa to 300 m at 0.1 hPa. Temperature accuracy is limited mainly by uncertainty in instrument characterization, and tangent-point pressure accuracy is limited mainly by the accuracy of spectroscopic parameters. Precisions are around 1 K and 100 m. Comparisons are presented among temperatures from MLS, the National Meteorological Center (NMC) stratospheric analysis and lidar stations at Table Mountain, California, Observatory of Haute Provence (OHP), France, and Goddard Spaceflight Center, Maryland. MLS temperatures tend to be 1-2 K lower than NMC and lidar, but MLS is often 5 - 10 K lower than NMC in the winter at high latitudes, especially within the northern hemisphere vortex. Winter MLS and OHP (44 deg N) lidar temperatures generally agree and tend to be lower than NMC. Problems with Version 3 MLS temperatures and tangent-point pressures are identified, but the high precision of MLS radiances will allow improvements with better algorithms planned for the future.

  4. Mare volcanism: Reinterpretation based on Kaguya Lunar Radar Sounder data

    NASA Astrophysics Data System (ADS)

    Oshigami, Shoko; Watanabe, Shiho; Yamaguchi, Yasushi; Yamaji, Atsushi; Kobayashi, Takao; Kumamoto, Atsushi; Ishiyama, Ken; Ono, Takayuki

    2014-05-01

    The Lunar Radar Sounder (LRS) onboard Kaguya (SELENE) detected widespread horizontal reflectors under some nearside maria. Previous studies estimated that the depths of the subsurface reflectors were up to several hundreds of meters and suggested that the reflectors were interfaces between mare basalt units. The comparison between the reflectors detected in the LRS data and surface age maps indicating the formation age of each basalt unit allows us to discuss the lower limit volume of each basalt unit and its space and time variation. We estimated volumes of basalt units in the ages of 2.7 Ga to 3.8 Ga in the nearside maria including Mare Crisium, Mare Humorum, Mare Imbrium, Mare Nectaris, Mare Serenitatis, Mare Smythii, and Oceanus Procellarum. The lower limit volumes of the geologic units estimated in this study were on the order of 103 to 104 km3. This volume range is consistent with the total amount of erupted lava flows derived from numerical simulations of thermal erosion models of lunar sinuous rille formation and is also comparable to the average flow volumes of continental flood basalt units formed after the Paleozoic and calculated flow volumes of Archean komatiite flows on the Earth. The lower limits of average eruption rates estimated from the unit volumes were on the order of 10-5 to 10-3 km3/yr. The estimated volumes of the geologic mare units and average eruption rate showed clear positive correlations with their ages within the same mare basin, while they vary among different maria compared within the same age range.

  5. Validation of UARS Microwave Limb Sounder Ozone Measurements

    NASA Technical Reports Server (NTRS)

    Froidevaux, L.; Read, W. G.; Lungu, T. A.; Cofield, R. E.; Fishbein, E. F.; Flower, D. A.; Jarnot, R. F.; Ridenoure, B. P.; Shippony, Z.; Waters, J. W.; Margitan, J. J.; McDermid, I. S.; Stachnik, R. A.; Peckham, G. E.; Braathen, G.; Deshler, T.; Fishman, J.; Hofmann, D. J.; Oltmans, S. J.

    1996-01-01

    This paper describes the validation of ozone data from the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS). The MLS ozone retrievals are obtained from the calibrated microwave radiances (emission spectra) in two separate bands, at frequencies near 205 and 183 GHz. Analyses described here focus on the MLS Version 3 data (the first set of files made publicly available). We describe results of simulations performed to assess the quality of the retrieval algorithms, in terms of both mixing ratio and radiance closure. From actual MLS observations, the 205-GHz ozone retrievals give better closure (smaller radiance residuals) than that from the 183-GHz measurements and should be considered more accurate from the calibration aspects. However, the 183-GHz data are less noise limited in the mesosphere and can provide the most useful scientific results in that region. We compare the retrieved 205-GHz ozone profiles in the middle-to lower stratosphere to ozonesonde measurements at a wide range of latitudes and seasons. Ground-based lidar data from Table Mountain, California, provide a good reference for comparisons at higher altitudes. Based on these analyses, comparisons with balloon-borne measurements and others, as well as a detailed budget of estimated uncertainties, MLS results appear to be generally of high quality, with some biases worth mentioning. Results for the lowermost stratosphere (approx. 50 to 100 bPa) are still in need of improvement. A set of estimated precision and accuracy values is derived for the MLS ozone data sets. We also comment on recent updates in the retrieval algorithms and their impact on ozone values.

  6. The UARS and EOS Microwave Limb Sounder (MLS) Experiments.

    NASA Astrophysics Data System (ADS)

    Waters, J. W.; Read, W. G.; Froidevaux, L.; Jarnot, R. F.; Cofield, R. E.; Flower, D. A.; Lau, G. K.; Pickett, H. M.; Santee, M. L.; Wu, D. L.; Boyles, M. A.; Burke, J. R.; Lay, R. R.; Loo, M. S.; Livesey, N. J.; Lungu, T. A.; Manney, G. L.; Nakamura, L. L.;  Perun, V. S.;  Ridenoure, B. P.;  Shippony, Z.;  Siegel, P. H.;  Thurstans, R. P.;  Harwood, R. S.;  Pumphrey, H. C.;  Filipiak, M. J.

    1999-01-01

    The Microwave Limb Sounder (MLS) experiments obtain measurements of atmospheric composition, temperature, and pressure by observations of millimeter- and submillimeter-wavelength thermal emission as the instrument field of view is scanned through the atmospheric limb. Features of the measurement technique include the ability to measure many atmospheric gases as well as temperature and pressure, to obtain measurements even in the presence of dense aerosol and cirrus, and to provide near-global coverage on a daily basis at all times of day and night from an orbiting platform. The composition measurements are relatively insensitive to uncertainties in atmospheric temperature. An accurate spectroscopic database is available, and the instrument calibration is also very accurate and stable. The first MLS experiment in space, launched on the (NASA) Upper Atmosphere Research Satellite (UARS) in September 1991, was designed primarily to measure stratospheric profiles of ClO, O3, H2O, and atmospheric pressure as a vertical reference. Global measurement of ClO, the predominant radical in chlorine destruction of ozone, was an especially important objective of UARS MLS. All objectives of UARS MLS have been accomplished and additional geophysical products beyond those for which the experiment was designed have been obtained, including measurement of upper-tropospheric water vapor, which is important for climate change studies. A follow-on MLS experiment is being developed for NASA's Earth Observing System (EOS) and is scheduled to be launched on the EOS CHEMISTRY platform in late 2002. EOS MLS is designed for many stratospheric measurements, including HOx radicals, which could not be measured by UARS because adequate technology was not available, and better and more extensive upper-tropospheric and lower-stratospheric measurements.

  7. Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations

    NASA Astrophysics Data System (ADS)

    Benson, R. F.

    1985-06-01

    In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or computer analysis. The signals of primary interest in the perigee study were found to be sounder-generated.

  8. Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations

    NASA Technical Reports Server (NTRS)

    Benson, R. F.

    1985-01-01

    In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or computer analysis. The signals of primary interest in the perigee study were found to be sounder-generated.

  9. Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations

    SciTech Connect

    Benson, R.F.

    1985-06-01

    In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or computer analysis. The signals of primary interest in the perigee study were found to be sounder-generated. 15 references.

  10. NIMBUS-5 sounder data processing system. Part 2: Results

    NASA Technical Reports Server (NTRS)

    Smith, W. L.; Woolf, H. M.; Hayden, C. M.; Shen, W. C.

    1975-01-01

    The Nimbus-5 spacecraft carries infrared and microwave radiometers for sensing the temperature distribution of the atmosphere. Methods developed for obtaining temperature profiles from the combined set of infrared and microwave radiation measurements are described. Algorithms used to determine (a) vertical temperature and water vapor profiles, (b) cloud height, fractional coverage, and liquid water content, (c) surface temperature, and (d) total outgoing longwave radiation flux are described. Various meteorological results obtained from the application of the Nimbus-5 sounding data processing system during 1973 and 1974 are presented.

  11. Advances on Sensitive Electron-injection based Cameras for Low-Flux, Short-Wave-Infrared Applications

    NASA Astrophysics Data System (ADS)

    Fathipour, Vala; Bonakdar, Alireza; Mohseni, Hooman

    2016-08-01

    Short-wave infrared (SWIR) photon detection has become an essential technology in the modern world. Sensitive SWIR detector arrays with high pixel density, low noise levels and high signal-to-noise-ratios are highly desirable for a variety of applications including biophotonics, light detection and ranging, optical tomography, and astronomical imaging. As such many efforts in infrared detector research are directed towards improving the performance of the photon detectors operating in this wavelength range. We review the history, principle of operation, present status and possible future developments of a sensitive SWIR detector technology, which has demonstrated to be one of the most promising paths to high pixel density focal plane arrays for low flux applications. The so-called electron-injection (EI) detector was demonstrated for the first time (in 2007). It offers an overall system-level sensitivity enhancement compared to the p-i-n diode due to a stable internal avalanche-free gain. The amplification method is inherently low noise, and devices exhibit an excess noise of unity. The detector operates in linear-mode and requires only bias voltage of a few volts. The stable detector characteristics, makes formation of high yield large-format, and high pixel density focal plane arrays less challenging compared to other detector technologies such as avalanche photodetectors. Detector is based on the mature InP material system (InP/InAlAs/GaAsSb/InGaAs), and has a cutoff wavelength of 1700 nm. It takes advantage of a unique three-dimensional geometry and combines the efficiency of a large absorbing volume with the sensitivity of a low-dimensional switch (injector) to sense and amplify signals. Current devices provide high-speed response ~ 5 ns rise time, and low jitter ~ 12 ps at room temperature. The internal dark current density is ~ 1 μA/cm2 at room temperature decreasing to 0.1 nA/cm2 at 160 K. EI detectors have been designed, fabricated, and tested during two

  12. Sounder-accelerated electrons radiate slow-Z-mode waves

    NASA Astrophysics Data System (ADS)

    James, G.

    During the OEDIPUS-C (OC) double-payload rocket experiment, waves were transmitted from a 19-m dipole on one subpayload and received at a distance of 1200 m on a similar dipole. Bistatic propagation was obtained in the slow-Z mode of propagation, i.e., at frequencies f in max{fc, fp} < quad f quad < quad fuh, where fc is the electron gyrofrequency, fp the plasma frequency and fuh the upper-hybrid-resonance frequency. Auroral hiss is generated in the slow-Z mode. In OC, the separation vector between the transmitter and receiver lay along a direction at about 5 from the axis of the Earth's magnetic field B. The Z-mode pulses were strong and significantly dispersed. Propagation near the upper oblique resonance cone was investigated using solutions of the complete electromagnetic hot-plasma dispersion relation. No solutions were found at the operating frequencies with the observed group delays and ray directions. An explanation has been proposed involving incoherent radiation from sounder-accelerated electrons (SAE). Published observations of SAE on OC show that the OC transmitting dipole produces strong SAE at energies from 10 eV up to 10 keV when the transmitting frequency sweeps through Z-mode frequency range. The near field of the transmitting dipole pushes SAE helically downward in the general direction of the receiver. At every instant, each SAE particle creates radiation that obeys the resonance condition f - mfc = (nf/c)cosθ Vcosα , where m is a signed integer, n the Z-mode refractive index, θ the angle between the direction of propagation of the radiation and B, V the electron speed and α its pitch angle. Using the reported SAE energies, it is found that time delays like those observed can be explained with Z-mode n and θ values, for m = 0, 1 or 2. The resonance condition and dispersion relation together require θ values near the upper-oblique resonance cone. Test-particle theory combined with the hot-plasma dispersion solution is used to predict the

  13. Microwave Moisture Sounder Feasibility Study. Phase 2. Retrieval Optimization

    DTIC Science & Technology

    1988-03-14

    and millimeter wave sensor ( .. n and imager ) data which extends the adopted operational algorithm based on a pirel’ statistically based retrieval of...SECURITY CLASSIFICATION OF THIS PAGE All other edtions are obsolete Unclassified Si. % * W | - ! 1 t- Cont of Block 19: characterize the spectral ...visible and (b) infrared GOES imager data ... ................................................. 55 3-1 Comparison of extinction coefficient (BEXT) and

  14. Study of Functional Infrared Imaging for Early Detection of Mucositis in Locally Advanced Head and Neck Cancer Treated With Chemoradiotherapy

    PubMed Central

    Cohen, Ezra E.W.; Ahmed, Omar; Kocherginsky, Masha; Shustakova, Galyna; Kistner-Griffin, Emily; Salama, Joseph K.; Yefremenko, Volodymyr; Novosad, Valentyn

    2013-01-01

    Background and Purpose Chemoradiotherapy (CRT) has led to improved efficacy in treating locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN) but has led to almost universal in-field mucositis. Patients treated with the same regimen often have differences in mucositis occurrence and severity. Mucositis induced via radiation is known to represent an intense inflammatory response histologically. We hypothesized that patients destined to display severe mucocutaneous toxicity would demonstrate greater alterations in thermal intensity early in therapy than identically treated counterparts. This will allow identification of patients that will require more intensive supportive care using thermal imaging technology. Materials and Methods Subjects with LA-SCCHN (oral cavity or oropharynx) being treated with the identical chemoradiotherapy regimen underwent baseline and weekly thermal imaging. Changes in skin temperature caused by mucositis and dermatitis compared with a reference area (T were calculated and correlated to grade of mucositis based on NCI-CTCAE 3.0. Results Thirty-four subjects were enrolled. Grade 3 mucositis and dermatitis was observed in 53% and 21%, respectively. We observed a statistically significant positive association between an early rise in T and mucositis grade (p value=0.03). Conclusions Thermal imaging is able to detect small and early changes in skin surface temperature that may be associated with development of mucositis in patients being treated with chemoradiotherapy. PMID:23988569

  15. The 4-Day Wave as Obvserved from the Upper Atmosphere Research Satellite Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Allen, D. R.; Stanford, J. L.

    1996-01-01

    The 4-day wave is an eastward moving quasi-nondispersive feature with period near 4 days occurring near the winter polar stratopause. This paper presents evidence of the 4-day feature in Microwave Limb Sounder (MLS) temperature, geopotential height and ozone data from the late Southern winters of 1992 and 1993.

  16. Calibration of the Microwave Limb Sounder on the Upper Atmosphere Research Satellite

    NASA Technical Reports Server (NTRS)

    Jarnot, Robert R.; Waters, Joe W.

    1994-01-01

    This paper describes pre-launch radiometric and spectral calibrations of the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS). Use of in-flight data for validation or refinement of calibration is described. The estimated uncertaint in calibrated radiance from pre-launch radiometric and spectral calibration data is better than 2% in most bands.

  17. Acoustic sounder system design for measurement of optical turbulence and wind profiles

    NASA Astrophysics Data System (ADS)

    Miller, Judith E.; Eaton, Frank D.; Stokes, Sheldon S.

    2000-07-01

    An Acoustic Sounder System has been installed on the side of the cliff at North Oscura Peak, WSMR to provide important refractive index structure parameter, Cn2 data for laser propagation tests. The acoustic sounder system records echo information that is used to provide 3D wind and optical turbulence profiles. The received signal is the product of the interaction of the transmitted acoustic pulse with the small scale atmospheric temperature variations. This information is displayed as a time-height display of the signal intensity. The frequency of the received signals are processed and converted into time histories of the horizontal wind field. The data from the Acoustic Sounder is calibrated with the hot-wire anemometer temperature structure parameter (Ct2) data, and meteorological data measured locally to produce the Cn2 profile. The design and location of the Acoustic Sounder System will be discussed along with the methodology of extracting the turbulence. Many days of data have been collected and representative data will be shown.

  18. Evolution of Satellite Imagers and Sounders for Low Earth Orbit and Technology Directions at NASA

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; McClain, Charles R.

    2010-01-01

    Imagers and Sounders for Low Earth Orbit (LEO) provide fundamental global daily observations of the Earth System for scientists, researchers, and operational weather agencies. The imager provides the nominal 1-2 km spatial resolution images with global coverage in multiple spectral bands for a wide range of uses including ocean color, vegetation indices, aerosol, snow and cloud properties, and sea surface temperature. The sounder provides vertical profiles of atmospheric temperature, water vapor cloud properties, and trace gases including ozone, carbon monoxide, methane and carbon dioxide. Performance capabilities of these systems has evolved with the optical and sensing technologies of the decade. Individual detectors were incorporated on some of the first imagers and sounders that evolved to linear array technology in the '80's. Signal-to-noise constraints limited these systems to either broad spectral resolution as in the case of the imager, or low spatial resolution as in the case of the sounder. Today's area 2-dimensional large format array technology enables high spatial and high spectral resolution to be incorporated into a single instrument. This places new constraints on the design of these systems and enables new capabilities for scientists to examine the complex processes governing the Earth System.

  19. The validation of ozone measurements from the improved stratospheric and mesospheric sounder

    NASA Technical Reports Server (NTRS)

    Connor, Brian J.; Scheuer, Christopher J.; Chu, D. A.; Remedios, John J.; Marks, C. J.; Rodgers, Clive D.; Taylor, Fredric W.

    1994-01-01

    We present preliminary results of the validation of ozone measurements from the Improved Stratospheric and Mesospheric Sounder (ISAMS). The indications are that the ISAMS provides ozone data which generally agrees with other experiments and climatological values, except in regions of large thermal gradients or high aerosol loading. Corrections for these effects will be included in future reprocessing of the data.

  20. Single Site Location with Ionospheric Specification from Oblique-Incidence Sounders.

    DTIC Science & Technology

    2014-09-26

    the sounder network has been made. Several tasks remain in the analysis of SSL- ICT data. Several of the other time periods in the data base can be...0, - , . , * - - 6 Elt -,R W CL CL a. a. a. a. a. a. I I * et I, 14 -NAI.,N I if. APPENDIX C Plots of tinV2 vs. cosx

  1. Shallow scattering layer in the subarctic pacific ocean: detection by high-frequency echo sounder.

    PubMed

    Barraclough, W E; Lebrasseur, R J; Kennedy, O D

    1969-10-31

    Shallow scattering layers consisting mainly of Calanus cristatus were detected on a trans-Pacific crossing to depths of 60 meters with a high-frequency echo sounder. Biomass estimates of these layers indicate concentrations of zoo-plankton that are greater and more extensive than previously reported in the open ocean.

  2. Determination of film processing specifications for the Apollo 17 S-209 lunar sounder experiment

    NASA Technical Reports Server (NTRS)

    Weinstein, M. S.

    1972-01-01

    The lunar sounder is described as a radar system operating at carrier frequencies of 5, 15, and 150 MHz. The radar echoes are recorded onto Kodak type S0-394 film through the use of an optical recorder utilizing a cathode ray tube as the exposing device. A processing configuration is determined with regard to linearity, dynamic range, and noise.

  3. High-powered Radar Sounders for the Investigation of Jupiter's Icy Moons

    NASA Technical Reports Server (NTRS)

    Safaeinili, A.; Rodriguez, E.; Edelstein, Wendy

    2003-01-01

    This talk will address the main drivers in the design of a radar sounder for the JIMO mission and provide a potential solution that will optimize the chances of success in the detection of ice/water interface and sub-surface stratigraphy.

  4. Instrument technology for magnetosphere plasma imaging from high Earth orbit. Design of a radio plasma sounder

    NASA Technical Reports Server (NTRS)

    Haines, D. Mark; Reinisch, Bodo W.

    1995-01-01

    The use of radio sounding techniques for the study of the ionospheric plasma dates back to G. Briet and M. A. Tuve in 1926. Ground based swept frequency sounders can monitor the electron number density (N(sub e)) as a function of height (the N(sub e) profile). These early instruments evolved into a global network that produced high-resolution displays of echo time delay vs frequency on 35-mm film. These instruments provided the foundation for the success of the International Geophysical Year (1958). The Alouette and International Satellites for Ionospheric Studies (ISIS) programs pioneered the used of spaceborne, swept frequency sounders to obtain N(sub e) profiles of the topside of the ionosphere, from a position above the electron density maximum. Repeated measurements during the orbit produced an orbital plane contour which routinely provided density measurements to within 10%. The Alouette/ISIS experience also showed that even with a high powered transmitter (compared to the low power sounder possible today) a radio sounder can be compatible with other imaging instruments on the same satellite. Digital technology was used on later spacecraft developed by the Japanese (the EXOS C and D) and the Soviets (Intercosmos 19 and Cosmos 1809). However, a full coherent pulse compression and spectral integrating capability, such as exist today for ground-based sounders (Reinisch et al., 1992), has never been put into space. NASA's 1990 Space Physics Strategy Implementation Study "The NASA Space Physics Program from 1995 to 2010" suggested using radio sounders to study the plasmasphere and the magnetopause and its boundary layers (Green and Fung, 1993). Both the magnetopause and plasmasphere, as well as the cusp and boundary layers, can be observed by a radio sounder in a high-inclination polar orbit with an apogee greater than 6 R(sub e) (Reiff et al., 1994; Calvert et al., 1995). Magnetospheric radio sounding from space will provide remote density measurements of

  5. Technology Development for the Advanced Technology Large Aperture Space Telescope (ATLAST) as a Candidate Large UV-Optical-Infrared (LUVOIR) Surveyor

    NASA Technical Reports Server (NTRS)

    Bolcar, Matthew R.; Balasubramanian, Kunjithapatha; Clampin, Mark; Crooke, Julie; Feinberg, Lee; Postman, Marc; Quijada, Manuel; Rauscher, Bernard; Redding, David; Rioux, Norman; Shaklan, Stuart; Stahl, H. Philip; Stahle, Carl; Thronson, Harley

    2015-01-01

    The Advanced Technology Large Aperture Space Telescope (ATLAST) team has identified five key technologies to enable candidate architectures for the future large-aperture ultraviolet/optical/infrared (LUVOIR) space observatory envisioned by the NASA Astrophysics 30-year roadmap, Enduring Quests, Daring Visions. The science goals of ATLAST address a broad range of astrophysical questions from early galaxy and star formation to the processes that contributed to the formation of life on Earth, combining general astrophysics with direct-imaging and spectroscopy of habitable exoplanets. The key technologies are: internal coronagraphs, starshades (or external occulters), ultra-stable large-aperture telescopes, detectors, and mirror coatings. Selected technology performance goals include: 1x10?10 raw contrast at an inner working angle of 35 milli-arcseconds, wavefront error stability on the order of 10 pm RMS per wavefront control step, autonomous on-board sensing & control, and zero-read-noise single-photon detectors spanning the exoplanet science bandpass between 400 nm and 1.8 µm. Development of these technologies will provide significant advances over current and planned observatories in terms of sensitivity, angular resolution, stability, and high-contrast imaging. The science goals of ATLAST are presented and flowed down to top-level telescope and instrument performance requirements in the context of a reference architecture: a 10-meter-class, segmented aperture telescope operating at room temperature (290 K) at the sun-Earth Lagrange-2 point. For each technology area, we define best estimates of required capabilities, current state-of-the-art performance, and current Technology Readiness Level (TRL) - thus identifying the current technology gap. We report on current, planned, or recommended efforts to develop each technology to TRL 5.

  6. Technology development for the Advanced Technology Large Aperture Space Telescope (ATLAST) as a candidate large UV-Optical-Infrared (LUVOIR) surveyor

    NASA Astrophysics Data System (ADS)

    Bolcar, Matthew R.; Balasubramanian, Kunjithapatham; Clampin, Mark; Crooke, Julie; Feinberg, Lee; Postman, Marc; Quijada, Manuel; Rauscher, Bernard; Redding, David; Rioux, Norman; Shaklan, Stuart; Stahl, H. Philip; Stahle, Carl; Thronson, Harley

    2015-09-01

    The Advanced Technology Large Aperture Space Telescope (ATLAST) team has identified five key technologies to enable candidate architectures for the future large-aperture ultraviolet/optical/infrared (LUVOIR) space observatory envisioned by the NASA Astrophysics 30-year roadmap, Enduring Quests, Daring Visions. The science goals of ATLAST address a broad range of astrophysical questions from early galaxy and star formation to the processes that contributed to the formation of life on Earth, combining general astrophysics with direct-imaging and spectroscopy of habitable exoplanets. The key technologies are: internal coronagraphs, starshades (or external occulters), ultra-stable large-aperture telescopes, detectors, and mirror coatings. Selected technology performance goals include: 1x10-10 raw contrast at an inner working angle of 35 milli-arcseconds, wavefront error stability on the order of 10 pm RMS per wavefront control step, autonomous on-board sensing and control, and zero-read-noise single-photon detectors spanning the exoplanet science bandpass between 400 nm and 1.8 μm. Development of these technologies will provide significant advances over current and planned observatories in terms of sensitivity, angular resolution, stability, and high-contrast imaging. The science goals of ATLAST are presented and flowed down to top-level telescope and instrument performance requirements in the context of a reference architecture: a 10-meter-class, segmented aperture telescope operating at room temperature (~290 K) at the sun-Earth Lagrange-2 point. For each technology area, we define best estimates of required capabilities, current state-of-the-art performance, and current Technology Readiness Level (TRL) - thus identifying the current technology gap. We report on current, planned, or recommended efforts to develop each technology to TRL 5.

  7. Direct assimilation of Chinese FY-3C Microwave Temperature Sounder-2 radiances in the global GRAPES system

    NASA Astrophysics Data System (ADS)

    Li, Juan; Liu, Guiqing

    2016-07-01

    FengYun-3C (FY-3C) is an operational polar-orbiting satellite carrying the new-generation microwave sounding instruments in China. This paper describes the assimilation of the FY-3C Microwave Temperature Sounder-2 (MWTS-2) radiances in the Global and Regional Assimilation and PrEdiction System (GRAPES) of China Meteorological Administration. A quality control (QC) procedure for the assimilation of MWTS-2 radiance is proposed. Extensive monitoring before assimilation shows that MWTS-2 observations exhibit a clear striping pattern. A technique combining principal component analysis (PCA) and ensemble empirical mode decomposition (EEMD) is applied to the observations to remove the striping noise. Cloudy field-of-views (FOVs) are identified by applying the Visible and InfrarRed Radiometer (VIRR) cloud fraction threshold of 76 %. Other QC steps are conducted in the follow order: (i) coastal FOVs are removed, (ii) eight outmost FOVs are not used, (iii) channel 5 data over sea ice and land are not used, (iv) channel 6 observations are not used if the terrain altitudes are higher than 500 m, and (v) outliers with large differences between observations and model simulations are removed. Approximately 83, 75, 40, and 40 % of the observations are removed by the proposed QC for channels 5-8, respectively. After QC, the global biases and standard deviations are reduced significantly. The assimilation of the MWTS-2 radiances shows a positive impact when the control experiment assimilates only conventional observations. The experiments also show that the analysis and forecast errors are slightly reduced when the striping noise is removed from the observations. The quality control scheme of extracting the striping noise may contribute to the analysis and forecast accuracy. The impact of MWTS-2 is neutral when the conventional data and other satellite data are all assimilated.

  8. Far-infrared protects vascular endothelial cells from advanced glycation end products-induced injury via PLZF-mediated autophagy in diabetic mice

    PubMed Central

    Chen, Cheng-Hsien; Chen, Tso-Hsiao; Wu, Mei-Yi; Chou, Tz-Chong; Chen, Jia-Rung; Wei, Meng-Jun; Lee, San-Liang; Hong, Li-Yu; Zheng, Cai-Mei; Chiu, I-Jen; Lin, Yuh-Feng; Hsu, Ching-Min; Hsu, Yung-Ho

    2017-01-01

    The accumulation of advanced glycation end products (AGEs) in diabetic patients induces vascular endothelial injury. Promyelocytic leukemia zinc finger protein (PLZF) is a transcription factor that can be activated by low-temperature far-infrared (FIR) irradiation to exert beneficial effects on the vascular endothelium. In the present study, we investigated the influence of FIR-induced PLZF activation on AGE-induced endothelial injury both in vitro and in vivo. FIR irradiation inhibited AGE-induced apoptosis in human umbilical vein endothelial cells (HUVECs). PLZF activation increased the expression of phosphatidylinositol-3 kinases (PI3K), which are important kinases in the autophagic signaling pathway. FIR-induced PLZF activation led to autophagy in HUVEC, which was mediated through the upregulation of PI3K. Immunofluorescence staining showed that AGEs were engulfed by HUVECs and localized to lysosomes. FIR-induced autophagy promoted AGEs degradation in HUVECs. In nicotinamide/streptozotocin-induced diabetic mice, FIR therapy reduced serum AGEs and AGEs deposition at the vascular endothelium. FIR therapy also reduced diabetes-induced inflammatory markers in the vascular endothelium and improved vascular endothelial function. These protective effects of FIR therapy were not found in PLZF-knockout mice. Our data suggest that FIR-induced PLZF activation in vascular endothelial cells protects the vascular endothelium in diabetic mice from AGE-induced injury. PMID:28071754

  9. Proceedings of the Second Infrared Detector Technology Workshop

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R. (Compiler)

    1986-01-01

    The workshop focused on infrared detector, detector array, and cryogenic electronic technologies relevant to low-background space astronomy. Papers are organized into the following categories: discrete infrared detectors and readout electronics; advanced bolometers; intrinsic integrated infrared arrays; and extrinsic integrated infrared arrays. Status reports on the Space Infrared Telescope Facility (SIRTF) and Infrared Space Observatory (ISO) programs are also included.

  10. GeoSTAR - A Synthetic Aperture Microwave Sounder for Geostationary Missions

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn; Wilson, William; Tanner, Alan; Kangaslahti, Pekka

    2004-01-01

    The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a new microwave atmospheric sounder under development. It will bring capabilities similar to those now available on low-earth orbiting environmental satellites to geostationary orbit - where such capabilities have not been available. GeoSTAR will synthesize the multimeter aperture needed to achieve the required spatial resolution, which will overcome the obstacle that has prevented a GEO microwave sounder from being implemented until now. The synthetic aperture approach has until recently not been feasible, due to the high power needed to operate the on-board high-speed massively parallel processing system required for 2D-synthesis, as well as a number of system and calibration obstacles. The development effort under way at JPL, with important contributions from the Goddard Space Flight Center and the University of Michigan, is intended to demonstrate the measurement concept and retire much of the technology risk.

  11. Underwater Acoustic Transponders Tracking While Mapping With A Multibeam Echo-Sounder

    NASA Astrophysics Data System (ADS)

    de Moustier, C. P.; Franzheim, A.; Testa, W.; Burns, J. M.; Foy, R.

    2010-12-01

    A 160 kHz multibeam echo-sounder was used to interrogate and receive the replies from custom-built miniature underwater acoustic transponders attached to the carapace of king crabs in Womens Bay, Alaska. This new application of multibeam echo-sounders combines acoustic tracking and mapping, thus providing environmental context to the tracking information. Each transponder replies with its own coded sequence that stands out from other echoes received by the sonar. Range and bearing of the replies from multiple transponders can be obtained in a single sonar ping. The king crab experiment was done in 25-35 m of water depth, and the system was successfully tested without animals at 190 m depth. Work supported by NOAA's Undersea Research Program Grant G4768, with field work support from NOAA-NMFS/AFSC/RACE and Electronic Navigation Ltd.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Photoconductive HgCdTe detector assemblies for the GOES imager and sounder instruments

    NASA Astrophysics Data System (ADS)

    Hartley, Jeanne M.; Reine, Marion B.; Terzis, C. L.; Verrilli, Anthony J.; Hassler, Richard A.; Lesondak, Edward P.

    1996-10-01

    The GOES Imager and Sounder instruments each utilize several HgCdTe photoconductive (PC) detectors and detector arrays for detection over the 6.5 to 14.7 micrometers region. These high performance detectors are integrated with germanium aplanat lenses and mounted in miniature hermetically sealed housings. There are demanding requirements on the radiometric performance of these detector assemblies. For LW Sounder detectors, the highest possible sensitivity achievable by a practical HgCdTe photoconductor at the operating temperatures of 100 to 105 K was required. Lockheed Martin designed, fabricated, tested, packaged, qualified, and delivered 7 of the 11 HgCdTe PC detector assemblies for GOES-8, and 9 of the 11 assemblies for GOES- 9. All the n-type HgCdTe starting material was grown at Lockheed Martin.

  14. Development of a micro-satellite compatible FTS sounder for sun-occultation measurements

    NASA Astrophysics Data System (ADS)

    Giaccari, Philippe; Moreau, Louis M.; Giroux, Jacques G.; Soucy, Marc-André

    2009-09-01

    The SciSat/ACE mission provided, and still provides, high quality and high spectral resolution measurements of the atmosphere with a FTS sounder in sun-occultation configuration. Based on the comprehensive results and models of SciSat/ACE it is foreseen that most of the desired information can also be retrieved from lower spectral resolution measurements with higher signal-to-noise ratio (SNR) and appropriate data treatment. With the Canadian Space Agency under the Space Technologies Development Program, ABB Analytical developed a small size sun-occultation sounder compatible with a micro-satellite platform that has identical throughput, spectral bandwidth and vertical resolution as ACE. The spectral resolution is decreased by a factor 25 (0.6 cm-1 instead of 0.024 cm-1 for ACE) whereas the SNR performance is highly increased with an equal factor (target of 2500 instead of 100 for ACE over most of the spectral bandwidth between 750 and 4000 cm-1).A prototype of the sun-occultation sounder was built, tested under various thermal conditions and subjected to vibrations similar to those expected at launch. An outdoor experiment was also conducted to test the instrument in sun-occultation conditions. The good behavior of the instrument indicates interesting opportunities for such small footprint sounder on a low-cost micro-satellite mission and potentially good earth coverage if several of such instruments are used in coordination. Depending on the scientific needs, it is possible to adapt the proposed instrument to increase the vertical resolution and/or to extend the measurements on lower altitudes due to the higher SNR performances.

  15. Wide Field Collimator 2 (WFC2) for GOES Imager and Sounder

    NASA Technical Reports Server (NTRS)

    Etemad, Shahriar; Bremer, James C.; Zukowski, Barbara J.; Pasquale, Bert A.; zukowski, Tmitri J.; Prince, Robert E.; O'Neill, Patrick A.; Ross, Robert W.

    2004-01-01

    Two of the GOES instruments, the Imager and the Sounder, perform scans of the Earth to provide a full disc picture of the Earth. To verify the entire scan process, an image of a target that covers an 18 deg. circular field-of-view is collimated and projected into the field of regard of each instrument. The Wide Field Collimator 2 (WFC2) has many advantages over its predecessor, WFC1, including lower thermal dissipation higher fir field MTF, smaller package, and a more intuitive (faster) focusing process. The illumination source is an LED array that emits in a narrow spectral band centered at 689 nm, within the visible spectral bands of the Imager and Sounder. The illumination level can be continuously adjusted electronically. Lower thermal dissipation eliminates the need for forced convection cooling and minimizes time to reach thermal stability. The lens system has been optimized for the illumination source spectral output and athernalized to remain in focus during bulk temperature changes within the laboratory environment. The MTF of the lens is higher than that of the WFC1 at the edge of FOV. The target is focused in three orthogonal motions, controlled by an ergonomic system that saves substantial time and produces a sharper focus. Key words: Collimator, GOES, Imager, Sounder, Projector

  16. A Fast Radiative Transfer Model for the Meteor- M satellite-based hyperspectral IR sounders

    NASA Astrophysics Data System (ADS)

    Uspensky, A. B.; Rublev, A. N.; Rusin, E. V.; Pyatkin, V. P.

    2014-12-01

    The methodological and computational aspects of Fast Radiative Transfer Model (FRTM) development designed for the analysis and validation of the data of measurements using satellite-based instrument-hyperspectral IR sounders of high spectral resolution—are considered. A description of the FRTM is given for the analysis and modeling of the measurements by the IRFS-2 IR Fourier spectrometer for polarorbiting meteorological satellites of the Meteor-M series based on the known RTTOV FRTM. Computational efficiency is estimated and the results of the verification of developed FRTM are presented. They were obtained from a comparison of model simulations with exact line-by-line calculations for the IRFS-2 IR sounder. The increase in computational performance and the accuracy of the FRTM, caused by the application of the algorithms of the principal components method, are discussed. The construction of radiative models, which use the algorithm of the Monte Carlo method and are applicable for the analysis and modeling of the data of IR sounders under conditions of cloudiness in the instrument field of view, is considered.

  17. Understanding intersatellite biases of microwave humidity sounders using global simultaneous nadir overpasses

    NASA Astrophysics Data System (ADS)

    John, Viju O.; Holl, Gerrit; Buehler, Stefan A.; Candy, Brett; Saunders, Roger W.; Parker, David E.

    2012-01-01

    Simultaneous nadir overpasses (SNOs) of polar-orbiting satellites are most frequent in polar areas but can occur at any latitude when the equatorial crossing times of the satellites become close owing to orbital drift. We use global SNOs of polar orbiting satellites to evaluate the intercalibration of microwave humidity sounders from the more frequent high-latitude SNOs. We have found based on sensitivity analyses that optimal distance and time thresholds for defining collocations are pixel centers less than 5 km apart and time differences less than 300 s. These stringent collocation criteria reduce the impact of highly variable surface or atmospheric conditions on the estimated biases. Uncertainties in the estimated biases are dominated by the combined radiometric noise of the instrument pair. The effects of frequency changes between different versions of the humidity sounders depend on the amount of water vapor in the atmosphere. There are significant scene radiance and thus latitude dependencies in the estimated biases and this has to taken into account while intercalibrating microwave humidity sounders. Therefore the results obtained using polar SNOs will not be representative for moist regions, necessitating the use of global collocations for reliable intercalibration.

  18. Atmospheric River Observations with the HAMSR Aircraft Microwave Sounder

    NASA Astrophysics Data System (ADS)

    Lambrigtsen, B.; Brown, S. T.; Schreier, M. M.; Dang, H. V. T.; Behrangi, A.

    2015-12-01

    The High Altitude MMIC Sounding Radiometer (HAMSR) was developed at the Jet Propulsion Laboratory in 2001 to serve as an aircraft based hurricane observatory. It initially flew on the high altitude ER-2 and later on the DC-8. More recently it was modified to fly on the Global Hawk UAV. It uses the most advanced technology and is among the most sensitive instruments of its kind. In addition to a number of NASA hurricane field campaigns - mostly in the North Atlantic, HAMSR has participated in two atmospheric river campaigns off the California coast, one in 2011 (WISPAR) and one in 2015 (CalWater2). We will discuss observations from the 2015 campaign, with particular focus on a flight over an atmsospheric river making landfall in central California in early February, as well as compare with highlights from the 2011 flights. Copyright 2015 California Institute of Technology. Government sponsorship acknowledged.

  19. Infrared Investigations.

    ERIC Educational Resources Information Center

    Lascours, Jean; Albe, Virginie

    2001-01-01

    Describes a series of simple and nontraditional experiments that enable students to discover the properties of infrared radiation by studying the propagation, reflection, diffusion, and refraction of infrared. The experiments rely on two modules, an infrared transmitter and an infrared receiver. (SAH)

  20. Instrument technology for magnetosphere plasma imaging from high Earth orbit. Design of a radio plasma sounder. Final report

    SciTech Connect

    Haines, D.M.; Reinisch, B.W.

    1995-01-01

    The use of radio sounding techniques for the study of the ionospheric plasma dates back to G. Briet and M. A. Tuve in 1926. Ground based swept frequency sounders can monitor the electron number density (N{sub e}) as a function of height (the N{sub e} profile). These early instruments evolved into a global network that produced high-resolution displays of echo time delay vs frequency on 35-mm film. These instruments provided the foundation for the success of the International Geophysical Year. The Alouette and International Satellites for Ionospheric Studies (ISIS) programs pioneered the used of spaceborne, swept frequency sounders to obtain N{sub e} profiles of the topside of the ionosphere, from a position above the electron density maximum. Repeated measurements during the orbit produced an orbital plane contour which routinely provided density measurements to within 10%. The Alouette/ISIS experience also showed that even with a high powered transmitter (compared to the low power sounder possible today) a radio sounder can be compatible with other imaging instruments on the same satellite. Digital technology was used on later spacecraft developed by the Japanese (the EXOS C and D) and the Soviets (Intercosmos 19 and Cosmos 1809). However, a full coherent pulse compression and spectral integrating capability, such as exist today for ground-based sounders (Reinisch et al.), has never been put into space. NASA`s 1990 Space Physics Strategy Implementation Study `The NASA Space Physics Program from 1995 to 2010` suggested using radio sounders to study the plasmasphere and the magnetopause and its boundary layers (Green and Fung). Both the magnetopause and plasmasphere, as well as the cusp and boundary layers, can be observed by a radio sounder in a high-inclination polar orbit with an apogee greater than 6 R{sub e} (Reiff et al.; Calvert et al.).

  1. Field-aligned electron density irregularities near 500 km. Equator to polar cap topside sounder Z mode observations

    NASA Astrophysics Data System (ADS)

    Benson, R. F.

    1984-04-01

    In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or compuer analysis. The signals of primary interest in the perigee study were found to be sounder-generated.

  2. Field-aligned electron density irregularities near 500 km. Equator to polar cap topside sounder Z mode observations

    NASA Technical Reports Server (NTRS)

    Benson, R. F.

    1984-01-01

    In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or compuer analysis. The signals of primary interest in the perigee study were found to be sounder-generated.

  3. Sounder-updated statistical model predictions of maximum usable frequency for HF sky wave predictions. Memorandum report

    SciTech Connect

    Reilly, M.H.; Daehler, M.

    1985-10-30

    Measured solar parameters, such as sunspot number or 10.7 cm flux, have traditionally been used as inputs to drive statistical-model predictions of maximum usable frequencies (MUFs) on HF radio sky wave paths of interest. Much greater accuracy can be obtained by using ionospheric sounder inputs to drive or update statistical-model predictions, and this is demonstrated here using oblique-incidence sounder data from the DoD Solid Shield exercises on May 12-14, 1981. From analysis of ionograms collected for several paths every fifteen minutes, it is found that deployment of a reasonable number of sounders in a large area, in order to update the simple statistical model, MINIMUF, yields MUF prediction capability on unsounded communication paths in the area within 0.4 MHz rms error. This value is obtained from real-time updating and a spatial interpolation process developed here, whereby data at sounder control points is interpolated to ionospheric reflection points for communication paths of interest. The results from the interpolation are found to be at least 20-30% more accurate than updating at any one of the nearby sounder control points. The updating procedure applies under day and night conditions, and also works well in a forecasting mode (not real-time), where it is found to work better in this case than a statistical trend line approach for daytime forecasting. (Author)

  4. Infrared Sky Surveys

    NASA Astrophysics Data System (ADS)

    Price, Stephan D.

    2009-02-01

    A retrospective is given on infrared sky surveys from Thomas Edison’s proposal in the late 1870s to IRAS, the first sensitive mid- to far-infrared all-sky survey, and the mid-1990s experiments that filled in the IRAS deficiencies. The emerging technology for space-based surveys is highlighted, as is the prominent role the US Defense Department, particularly the Air Force, played in developing and applying detector and cryogenic sensor advances to early mid-infrared probe-rocket and satellite-based surveys. This technology was transitioned to the infrared astronomical community in relatively short order and was essential to the success of IRAS, COBE and ISO. Mention is made of several of the little known early observational programs that were superseded by more successful efforts.

  5. Preliminary validation of the refractivity from the new radio occultation sounder GNOS/FY-3C

    NASA Astrophysics Data System (ADS)

    Liao, Mi; Zhang, Peng; Yang, Guang-Lin; Bi, Yan-Meng; Liu, Yan; Bai, Wei-Hua; Meng, Xiang-Guang; Du, Qi-Fei; Sun, Yue-Qiang

    2016-03-01

    As a new member of the space-based radio occultation sounders, the GNOS (Global Navigation Satellite System Occultation Sounder) mounted on Fengyun-3C (FY-3C) has been carrying out atmospheric sounding since 23 September 2013. GNOS takes approximately 800 daily measurements using GPS (Global Positioning System) and Chinese BDS (BeiDou navigation satellite) signals. In this work, the atmospheric refractivity profiles from GNOS were compared with the ones obtained from the co-located ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis. The mean bias of the refractivity obtained through GNOS GPS (BDS) was found to be approximately -0.09 % (-0.04 %) from the near surface to up to 46 km. While the average standard deviation was approximately 1.81 % (1.26 %), it was as low as 0.75 % (0.53 %) in the range of 5-25 km, where best sounding results are usually achieved. Further, COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) and MetOp/ GRAS (GNSS Receiver for Atmospheric Sounding) radio occultation data were compared with the ECMWF reanalysis; the results thus obtained could be used as reference data for GNOS. Our results showed that GNOS/FY-3C meets the design requirements in terms of accuracy and precision of the sounder. It possesses a sounding capability similar to COSMIC and MetOp/GRAS in the vertical range of 0-30 km, though it needs further improvement above 30 km. Overall, it provides a new data source for the global numerical weather prediction (NWP) community.

  6. Assimilating synthetic hyperspectral sounder temperature and humidity retrievals to improve severe weather forecasts

    NASA Astrophysics Data System (ADS)

    Jones, Thomas A.; Koch, Steven; Li, Zhenglong

    2017-04-01

    Assimilation of hyperspectral sounder data into numerical weather prediction (NWP) models has proven vital to generating accurate model analyses of tropospheric temperature and humidity where few conventional observations exist. Applications to storm-scale models are limited since the low temporal resolution provided by polar orbiting sensors cannot adequately sample rapidly changing environments associated with high impact weather events. To address this limitation, hyperspectral sounders have been proposed for geostationary orbiting satellites, but these have yet to be built and launched in part due to much higher engineering costs and a lack of a definite requirement for the data. This study uses an Observation System Simulation Experiment (OSSE) approach to simulate temperature and humidity profiles from a hypothetical geostationary-based sounder from a nature run of a high impact weather event on 20 May 2013. The simulated observations are then assimilated using an ensemble adjustment Kalman filter approach, testing both hourly and 15 minute cycling to determine their relative effectiveness at improving the near storm environment. Results indicate that assimilating both temperature and humidity profiles reduced mid-tropospheric both mean and standard deviation of analysis and forecast errors compared to assimilating conventional observations alone. The 15 minute cycling generally produced the lowest errors while also generating the best 2-4 hour updraft helicity forecasts of ongoing convection. This study indicates the potential for significant improvement in short-term forecasting of severe storms from the assimilation of hyperspectral geostationary satellite data. However, more studies are required using improved OSSE designs encompassing multiple storm environments and additional observation types such as radar reflectivity to fully define the effectiveness of assimilating geostationary hyperspectral observations for high impact weather forecasting

  7. IMAGE Observations of Sounder Stimulated and Naturally Occurring Fast Z mode Cavity Noise

    NASA Astrophysics Data System (ADS)

    Sonwalkar, V. S.; Taylor, C.; Reddy, A.

    2015-12-01

    We report first observations of sounder stimulated and naturally occurring fast Z mode (ZM) cavity noise detected by the Radio Plasma Imager (RPI) on the IMAGE satellite. The fast Z mode cavity noise is a banded, structure-less radio emission trapped inside fast Z mode cavities, which are characterized by a minimum (fz,min) in fast Z mode cut-off frequency (fz) along a geomagnetic field line [Gurnett et al., JGR, 1983]. Fast Z mode waves reflect at fz ~ f, where f is the wave frequency. Waves in the frequency range fz,min < f < fz,max, where fz,max is the maximum fz above fz,min altitude, are trapped within the cavity as they bounce back and forth between reflection altitudes (fz ~ f) above and below the fz,min altitude. These trapped waves will be observed by a satellite passing through the cavity. The observed cavity noise lower cutoff is at the local Z mode cut-off frequency (fz,Sat) and the upper cut-off is presumably close to fz,max. The cavity noise is observed typically inside the plasmasphere. Comparison of cavity noise as observed on the plasmagram obtained during active sounding with that observed on the dynamic spectra obtained from the interspersed passive wave measurements indicate that the cavity noise is either stimulated by transmissions from the sounder (RPI) or is of natural origin. The sounder stimulated noise is often accompanied by fast Z mode echoes. The naturally occurring cavity noise is observed on both the plasmagram and the dynamic spectra. We believe the stimulated cavity noise is generated due to scattering from small-scale irregularities of waves transmitted by RPI. One potential candidate for the source of naturally occurring Z mode cavity noise is the ring current electrons that can generate fast ZM waves via higher order cyclotron resonance [Nishimura et al., Earth Planets Space, 2007].

  8. Advances in nanomaterial-based microwaves and infrared wave-assisted tryptic digestion for ultrafast proteolysis and rapid detection by MALDI-MS.

    PubMed

    Kailasa, Suresh Kumar; Wu, Hui-Fen

    2014-01-01

    The unique physical/chemical properties of nanomaterials have significant impacts in electromagnetic waves (microwave and infrared waves)-assisted tryptic digestion approaches by using them as heat absorbers to expedite digestion and as affinity probes to enrich digested proteins prior to MALDI-MS analysis. We review recent developments in electromagnetic waves (microwaves and infrared waves)-assisted proteolysis using nanomaterials as heat absorbers and as affinity probes for analysis of digested proteins in MALDI-MS. New trends in ultrafast proteolysis (nonphosphoproteins- lysozyme, cytochrome c, myoglobin and bovine serum albumin (BSA); phosphoproteins- α- and β- caseins) using nanomaterials based microwaves and infrared (IR) waves assisted digestion approaches for rapid identification of digested proteins in the MALDI-MS.

  9. Recent advances in mid- and near-infrared spectroscopy with applications for research and teaching, focusing on petrochemistry and biotechnology relevant products

    NASA Astrophysics Data System (ADS)

    Heise, H. M.; Fritzsche, J.; Tkatsch, H.; Waag, F.; Karch, K.; Henze, K.; Delbeck, S.; Budde, J.

    2013-11-01

    Mid- and near-infrared spectroscopy is introduced as a versatile analytical method for characterizing liquid and solid chemicals as obtained from petrochemistry and biotechnology processes. Besides normal transmission measurements, special equipment with silver halide fiber-optic probes allowing efficient analysis based on mid-infrared attenuated total reflection, and an accessory for near-infrared diffuse reflection measurements, are presented. The latter technique can be used advantageously for powdered samples such as microalgae biomass and polysaccharides, as well as for different tissues such as meat samples. The advantages and disadvantages of both methods, which can be used for industrial process monitoring and chemical quality control applications, are discussed, and have been used in several research projects of BSc students within their degree course of bio- and nano-technologies of our University of Applied Sciences.

  10. Phase Change Material for Temperature Control of Imager or Sounder on GOES Type Satellites in GEO

    NASA Technical Reports Server (NTRS)

    Choi, Michael K.

    2014-01-01

    This paper uses phase change material (PCM) in the scan cavity of an imager or sounder on satellites in geostationary orbit (GEO) to maintain the telescope temperature stable. When sunlight enters the scan aperture, solar heating causes the PCM to melt. When sunlight stops entering the scan aperture, the PCM releases the thermal energy stored to keep the components in the telescope warm. It has no moving parts or bimetallic springs. It reduces heater power required to make up the heat lost by radiation to space through the aperture. It is an attractive thermal control option to a radiator with a louver and a sunshade.

  11. Martian Weather and Climate: Initial Results from the Mars Climate Sounder

    NASA Astrophysics Data System (ADS)

    McCleese, D. J.; Schofield, J. T.; Taylor, F. W.; Calcutt, S. B.; Foote, M.; Kass, D.; Leovy, C.; Paige, D.; Read, P.; Zurek, R.; Abdou, W.; Ahrenson, O.; Lawson, G.; Backus, C.; Kleinbohl, A.; Lewis, S.; Teanby, N.; Irwin, P.; Read, P.; Wood, S.; Bowles, N.; Richardson, M.

    2007-08-01

    The Mars Climate Sounder experiment on the 2006 Mars Reconnaissance Orbiter is the latest attempt, following unfortunate failures with Mars Observer in 1993 and Mars Climate Orbiter in 1999, to characterize the Martian atmosphere with the sort of coverage and precision achieved by terrestrial weather satellites. It is expected to lead to corresponding improvements in our understanding of meteorological phenomena such as surface winds and global dust storms, and to enable improved general circulation models of the Martian atmosphere for climate studies on a range of timescales. Some initial results from the first year of measurements will be presented and described.

  12. Thermal Tides in the Martian Middle Atmosphere as Seen by the Mars Climate Sounder

    PubMed Central

    Lee, C.; Lawson, W. G.; Richardson, M. I.; Heavens, N. G.; Kleinböhl, A.; Banfield, D.; McCleese, D. J.; Zurek, R.; Kass, D.; Schofield, J. T.; Leovy, C. B.; Taylor, F. W.; Toigo, A. D.

    2016-01-01

    The first systematic observations of the middle atmosphere of Mars (35km–80km) with the Mars Climate Sounder (MCS) show dramatic patterns of diurnal thermal variation, evident in retrievals of temperature and water ice opacity. At the time of writing, the dataset of MCS limb retrievals is sufficient for spectral analysis within a limited range of latitudes and seasons. This analysis shows that these thermal variations are almost exclusively associated with a diurnal thermal tide. Using a Martian General Circulation Model to extend our analysis we show that the diurnal thermal tide dominates these patterns for all latitudes and all seasons. PMID:27630378

  13. LASA (Lidar Atmospheric Sounder and Altimeter) Earth Observing System. Volume 2D: Instrument Panel Report

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The Earth Observing System (Eos) will provide an ideal forum in which the stronly synergistic characteristics of the lidar systems can be used in concert with the characteristics of a number of other sensors to better understand the Earth as a system. Progress in the development of more efficient and long-lasting laser systems will insure their availability in the Eos time frame. The necessary remote-sensing techniques are being developed to convert the Lidar Atmospheric Sounder and Altimeter (LASA) observations into the proper scientific parameters. Each of these activities reinforces the promise that LASA and GLRS will be a reality in the Eos era.

  14. Tropical stratospheric water vapor measured by the Microwave Limb Sounder (MLS)

    NASA Astrophysics Data System (ADS)

    Carr, E. S.; Harwood, R. S.; Mote, P. W.; Peckham, G. E.; Suttie, R. A.; Lahoz, W. A.; O'Neill, A.; Froidevaux, L.; Jarnot, R. F.; Read, W. G.; Waters, J. W.; Swinbank, R.

    1995-03-01

    The lower stratospheric variability of equatorial water vapor, measured by the Microwave Limb Sounder (MLS), follows an annual cycle modulated by the quasi-biennial oscillation. At levels higher in the stratosphere, water vapor measurements exhibit a semiannual oscillatory signal with the largest amplitudes at 2.2 and 1hPa. Zonal-mean cross sections of MLS water vapour are consistent with previous satellite measurements from the LIMS and SAGE II instruments in that they show water vapor increasing upwards and polewards from a well defined minimum in the tropics. The minimum values vary in height between the retrieved 46 and 22hPa pressure levels.

  15. Comparison of airborne lidar measurements with 420 kHz echo-sounder measurements of zooplankton.

    PubMed

    Churnside, James H; Thorne, Richard E

    2005-09-10

    Airborne lidar has the potential to survey large areas quickly and at a low cost per kilometer along a survey line. For this reason, we investigated the performance of an airborne lidar for surveys of zooplankton. In particular, we compared the lidar returns with echo-sounder measurements of zooplankton in Prince William Sound, Alaska. Data from eight regions of the Sound were compared, and the correlation between the two methods was 0.78. To obtain this level of agreement, a threshold was applied to the lidar return to remove the effects of scattering from phytoplankton.

  16. Thermal Tides in the Martian Middle Atmosphere as Seen by the Mars Climate Sounder.

    PubMed

    Lee, C; Lawson, W G; Richardson, M I; Heavens, N G; Kleinböhl, A; Banfield, D; McCleese, D J; Zurek, R; Kass, D; Schofield, J T; Leovy, C B; Taylor, F W; Toigo, A D

    2009-03-01

    The first systematic observations of the middle atmosphere of Mars (35km-80km) with the Mars Climate Sounder (MCS) show dramatic patterns of diurnal thermal variation, evident in retrievals of temperature and water ice opacity. At the time of writing, the dataset of MCS limb retrievals is sufficient for spectral analysis within a limited range of latitudes and seasons. This analysis shows that these thermal variations are almost exclusively associated with a diurnal thermal tide. Using a Martian General Circulation Model to extend our analysis we show that the diurnal thermal tide dominates these patterns for all latitudes and all seasons.

  17. Performance of a 1-micron, 1-joule Coherent Launch Site Atmospheric Wind Sounder

    NASA Technical Reports Server (NTRS)

    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.

  18. Preliminary Evaluation of Preoperative Chemohormonotherapy-Induced Reduction of the Functional Infrared Imaging Score in Patients with Locally Advanced Breast Cancer

    DTIC Science & Technology

    2001-10-25

    ADVANCED BREAST CANCER John R. Keyserlingk1, Mariam Yassa1 Paul Ahlgren1 and Normand Belliveau1 Ville Marie Oncology Center; St. Mary’s Hospital...Montreal, Canada Abstract: 20 successive patients who received preoperative chemohormonotherapy (PCT) for locally advanced breast cancer underwent high...INTRODUCTION Approximately 10% of our current breast cancer patients present with sufficient tumor load to be classified as having locally advanced breast

  19. Improved wide-field collimator for dynamic testing of the GOES imager and sounder

    NASA Astrophysics Data System (ADS)

    Bremer, James C.; Etemad, Shahriar; Zukowski, Barbara J.; Pasquale, Bert A.; Zukowski, Tmitri J.; Prince, Robert E.; Holmes, Vincent; Ryskewich, John A.; O'Neill, Patrick; Murphy-Morris, Jeanine E.

    2002-09-01

    The GOES Imager and Sounder instruments each observe the full Earth disk, 17.4° in diameter, from geostationary orbit. Pre-launch, each instrument's dynamic scanning performance is tested using the projection of a test pattern from a wide-field collimator. We are fabricating a second wide-field collimator (WFC2) to augment this test program. The WFC2 has several significant advantages over the existing WFC1. The WFC2 target illumination system uses an array of light-emitting diodes (LEDs) radiating at 680nm, which is within the visible bands of both the Imager and Sounder. The light from the LEDs is projected through a non-Lambertian diffuser plate and the target plate to the pupil of the projection lens. The WFC2's power dissipation is much lower than that of WFC1, decreasing stabilization time and eliminating the need for cooling fans. The WFC2's custom-designed 5-element projection lens has the same effective focal length (EFL) as the WFC1 projection lens. The WFC2 lens is optimized for the LED's narrow spectral band simplifying the design and improving image quality. The target plate is mounted in a frame with a mechanized micro-positioner system that controls three degrees of freedom: tip, tilt, and focus. The tip and tilt axes intersect in the WFC's image plane, and all adjustments are controlled remotely by the operator observing the target plate through an auto-collimating telescope.

  20. Preliminary validation of refractivity from a new radio occultation sounder GNOS/FY-3C

    NASA Astrophysics Data System (ADS)

    Liao, M.; Zhang, P.; Yang, G. L.; Bi, Y. M.; Liu, Y.; Bai, W. H.; Meng, X. G.; Du, Q. F.; Sun, Y. Q.

    2015-09-01

    As a new member of space-based radio occultation sounder, the GNOS (Global Navigation Satellite System Occultation Sounder) mounted on FY-3C has been carrying out the atmospheric sounding since 23 September 2013. GNOS takes a daily measurement up to 800 times with GPS (Global Position System) and Chinese BDS (BeiDou navigation satellite) signals. The refractivity profiles from GNOS are compared with the co-located ECMWF (European Centre for Medium-Range Weather Forecasts) analyses in this paper. Bias and standard deviation have being calculated as the function of altitude. The mean bias is about 0.2 % from the near surface to 35 km. The average standard deviation is within 2 % while it is down to about 1 % in the range 5-30 km where best soundings are usually made. To evaluate the performance of GNOS, COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) and GRAS/METOP-A (GNSS Receiver for Atmospheric Sounding) data are also compared to ECMWF analyses as the reference. The results show that GNOS/FY-3C meets the requirements of the design well. It possesses a sounding capability similar to COSMIC and GRAS in the vertical range of 0-30 km, though it needs improvement in higher altitude. Generally, it provides a new data source for global NWP (numerical weather prediction) community.

  1. A bat inspired technique for clutter reduction in radar sounder systems

    NASA Astrophysics Data System (ADS)

    Carrer, L.; Bruzzone, L.

    2016-10-01

    Radar Sounders are valuable instruments for subsurface investigation. They are widely employed for the study of planetary bodies around the solar system. Due to their wide antenna beam pattern, off-nadir surface reflections (i.e. clutter) of the transmitted signal can compete with echoes coming from the subsurface thus masking them. Different strategies have been adopted for clutter mitigation. However, none of them proved to be the final solution for this specific problem. Bats are very well known for their ability in discriminating between a prey and unwanted clutter (e.g. foliage) by effectively employing their sonar. According to recent studies, big brown bats can discriminate clutter by transmitting two different carrier frequencies. Most interestingly, there are many striking analogies between the characteristics of the bat sonar and the one of a radar sounder. Among the most important ones, they share the same nadir acquisition geometry and transmitted signal type (i.e. linear frequency modulation). In this paper, we explore the feasibility of exploiting frequency diversity for the purpose of clutter discrimination in radar sounding by mimicking unique bats signal processing strategies. Accordingly, we propose a frequency diversity clutter reduction method based on specific mathematical conditions that, if verified, allow the disambiguation between the clutter and the subsurface signal to be performed. These analytic conditions depend on factors such as difference in central carrier frequencies, surface roughness and subsurface material properties. The method performance has been evaluated by different simulations of meaningful acquisition scenarios which confirm its clutter reduction effectiveness.

  2. Terahertz Limb Sounder for Lower Thermosphere Wind, Temperature, and Atomic Oxygen Density Measurements

    NASA Astrophysics Data System (ADS)

    Yee, J. H.; Boldt, J.; Wu, D. L.; Mehdi, I.; Schlecht, E.

    2015-12-01

    In this paper, we present the concept of a high-sensitivity heterodyne spectrometer operating at Terahertz (THz) frequency for global lower thermospheric neutral wind, temperature and atomic oxygen density measurements from a low earth orbit. The instrument, THz Limb Sounder (TLS) is aimed to provide, for the first time, global neutral wind/temperature/density profile measurements globally during day and night, with focus at altitudes of 100-150 km where most of the ion-neutral energy/momentum couplings take place. It is an ambient-temperature Schottky diode based all solid-state heterodyne spectrometer designed to extend the limb sounding technique employed by Microwave Limb Sounder for density/temperature/wind measurements by measuring the Doppler line shape of atomic oxygen (OI) fine structure emission at 2.06THz. This atomic oxygen line emission is very bright and distributed nearly uniformly globally (at all latitudes including high latitude aurora particle precipitation regions) and temporally (at all local times during both day and night), thus ideal for thermospheric remote sensing. TLS is an ambient-temperature Schottky diode based heterodyne receiver system The TLS instrument concept, measurement methodology, receiver performance, and the expected measurement capability will be presented and discussed in this paper.

  3. Radar Sounder

    DTIC Science & Technology

    1988-09-01

    over the shorter time period (resulting in a multilook SAR ) with the result that spatial resolution, the usual r~ason for using SAR techniques, degrades...Field - - - ALT 21. Sea Surface Topography - - - SAR , ALT 22. Ocean Waves (sea, swell, surf) V. Good Some V. Good SAR , ALT * with additional lower freq...OLS - Operational Line-scan System radiometer (4-6 GHz?) ALT - Altimeter •* good at low microwave SAR - Synthetic Aperture frequencies Radar + over

  4. Subsurface sounders

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Airborne or spaceborne electromagnetic systems used to detect subsurface features are discussed. Data are given as a function of resistivity of ground material, magnetic permeability of free space, and angular frequency. It was noted that resistivities vary with the water content and temperature.

  5. Infrared Fiber Optic Sensors

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Successive years of Small Business Innovation Research (SBIR) contracts from Langley Research Center to Sensiv Inc., a joint venture between Foster-Miller Inc. and Isorad, Ltd., assisted in the creation of remote fiber optic sensing systems. NASA's SBIR interest in infrared, fiber optic sensor technology was geared to monitoring the curing cycles of advanced composite materials. These funds helped in the fabrication of an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. Foster-Miller ingenuity allowed infrared transmitting optical fibers to combine with Fourier Transform Infrared spectroscopy to enable remote sensing. Sensiv probes operate in the mid-infrared range of the spectrum, although modifications to the instrument also permits its use in the near-infrared region. The Sensiv needle-probe is built to be placed in a liquid or powder and analyze the chemicals in the mixture. Other applications of the probe system include food processing control; combustion control in furnaces; and maintenance problem solving.

  6. Asian dust height and infrared optical depth retrievals over land from hyperspectral longwave infrared radiances

    NASA Astrophysics Data System (ADS)

    Yao, Zhigang; Li, Jun; Han, Hyo-Jin; Huang, Allen; Sohn, B. J.; Zhang, Peng

    2012-10-01

    The dust top height and infrared optical depth over land are retrieved from the Atmospheric Infrared Sounder (AIRS) longwave infrared measurements by using a one-dimensional-variation retrieval algorithm for different Asian dust storms. By combining particle size measurements from a 10-year ground observation data set from the Dunhuang Skynet station located to the east of the Taklimakan Desert in China and the Optical Properties of Aerosols and Clouds data set of optical properties, the mineral dust scattering and absorption coefficients are obtained and then used to compute brightness temperatures with RTTOV 9.3. The retrieved dust thermal infrared optical depths are compared with the Ozone Monitoring Instrument and Moderate Resolution Imaging Spectroradiometer (MODIS) products. The retrieved dust top heights are compared against the extinction backscatter profiles obtained from the Cloud-Aerosol Lidar with Orthogonal Polarization lidar. Infrared optical depths from AIRS correlate favorably with visible optical depths from MODIS, and dust top heights agree reasonably with lidar observations for the single-layered dust storms over the Taklimakan Desert.

  7. Hyperspectral Microwave Atmospheric Sounder (HyMas) - New Capability in the CoSMIR-CoSSIR Scanhead

    NASA Technical Reports Server (NTRS)

    Hilliard, L. M.; Racette, P. E.; Blackwell, W.; Galbraith, C.; Thompson, E.

    2015-01-01

    Lincoln Laboratory and NASA's Goddard Space Flight Center have teamed to re-use an existing instrument platform, the CoSMIRCoSSIR system for atmospheric sounding, to develop a new capability in hyperspectral filtering, data collection, and display. The volume of the scanhead accomodated an intermediate frequency processor(IFP), that provides the filtering and digitization of the raw data and the interoperable remote component (IRC) adapted to CoSMIR, CoSSIR, and HyMAS that stores and archives the data with time tagged calibration and navigation data.The first element of the work is the demonstration of a hyperspectral microwave receiver subsystem that was recently shown using a comprehensive simulation study to yield performance that substantially exceeds current state-of-the-art. Hyperspectral microwave sounders with 100 channels offer temperature and humidity sounding improvements similar to those obtained when infrared sensors became hyperspectral, but with the relative insensitivity to clouds that characterizes microwave sensors. Hyperspectral microwave operation is achieved using independent RF antennareceiver arrays that sample the same areavolume of the Earths surfaceatmosphere at slightly different frequencies and therefore synthesize a set of dense, finely spaced vertical weighting functions. The second, enabling element of the proposal is the development of a compact 52-channel Intermediate Frequency processor module. A principal challenge in the development of a hyperspectral microwave system is the size of the IF filter bank required for channelization. Large bandwidths are simultaneously processed, thus complicating the use of digital back-ends with associated high complexities, costs, and power requirements. Our approach involves passive filters implemented using low-temperature co-fired ceramic (LTCC) technology to achieve an ultra-compact module that can be easily integrated with existing RF front-end technology. This IF processor is universally

  8. Hyperspectral Microwave Atmospheric Sounder (HyMAS) - New Capability in the CoSMIR-CoSSIR Scanhead

    NASA Technical Reports Server (NTRS)

    Hilliard, Lawrence; Racette, Paul; Blackwell, William; Galbraith, Christopher; Thompson, Erik

    2015-01-01

    Lincoln Laboratory and NASA's Goddard Space Flight Center have teamed to re-use an existing instrument platform, the CoSMIR/CoSSIR system for atmospheric sounding, to develop a new capability in hyperspectral filtering, data collection, and display. The volume of the scanhead accomodated an intermediate frequency processor(IFP), that provides the filtering and digitization of the raw data and the interoperable remote component (IRC) adapted to CoSMIR, CoSSIR, and HyMAS that stores and archives the data with time tagged calibration and navigation data. The first element of the work is the demonstration of a hyperspectral microwave receiver subsystem that was recently shown using a comprehensive simulation study to yield performance that substantially exceeds current state-of-the-art. Hyperspectral microwave sounders with approximately 100 channels offer temperature and humidity sounding improvements similar to those obtained when infrared sensors became hyperspectral, but with the relative insensitivity to clouds that characterizes microwave sensors. Hyperspectral microwave operation is achieved using independent RF antenna/receiver arrays that sample the same area/volume of the Earth's surface/atmosphere at slightly different frequencies and therefore synthesize a set of dense, finely spaced vertical weighting functions. The second, enabling element of the proposal is the development of a compact 52-channel Intermediate Frequency processor module. A principal challenge in the development of a hyperspectral microwave system is the size of the IF filter bank required for channelization. Large bandwidths are simultaneously processed, thus complicating the use of digital back-ends with associated high complexities, costs, and power requirements. Our approach involves passive filters implemented using low-temperature co-fired ceramic (LTCC) technology to achieve an ultra-compact module that can be easily integrated with existing radio frequency front-end technology

  9. Outgoing long-wave radiation computed from HIRS2/MSU soundings. [High InfraRed Spectrometer/Microwave Sounding Unit

    SciTech Connect

    Wu, M.C.; Susskind, J. )

    1990-05-20

    Fields of outgoing long-wave radiation (OLR) have been computed using geophysical parameters retrieved from analysis of HIRS2/MSU sounding data as input to a modified version of the Wu-Kaplan radiation code used in the Goddard Laboratory for Atmospheres fourth-order general circulation model. Monthly mean results for 1979 agree with monthly mean OLR fields measured by the Nimbus 7 Earth radiation budget (ERB) broadband narrow field of view instrument within standard deviations of 6.3 W/m{sup 2} but with a global mean bias of 8.0 W/m{sup 2}. Results are shown for July 1979. The areas of disagreement between high-resolution infrared radiation sounder OLR and ERB OLR are small but spatially coherent with patterns which may be related to sampling differences. The difference patterns are much less extensive than those between OLR derived from advanced very high resolution radiometer 11-{mu}m observations and ERB OLR. The ability to compute OLR from geophysical parameters is complementary to direct measurement of OLR because it enables one to attribute changes in OLR in space and time to changes in other geophysical parameters. In addition, it allows one to compute fields not directly measurable from satellite, such as the difference of the upward long-wave flux between the surface and the top of the atmosphere and the long-wave cloud radiative forcing.

  10. Advances in soil mapping: Mapping quartz content of soil surface using airborne hyperspectral remote sensing in the longwave-infrared region

    NASA Astrophysics Data System (ADS)

    Weksler, Shahar; Notesco, Gila; Ben-Dor, Eyal

    2016-04-01

    Hyperspectral remote sensing in the longwave-infrared (LWIR) spectral region has proven to be a new and efficient tool for mineral mapping (Adar et al. 2013). Minerals which are featureless in the visible, near-infrared and shortwave-infrared regions, e.g., quartz, have a unique fingerprint in the LWIR region (8-12 μm). This spectral region adds to the optical region in which several important minerals can be characterized with significant features (e.g., clay). Accordingly, using airborne hyperspectral remote-sensing data in the LWIR region is an important and practical means of classifying and quantifying minerals. Day and night airborne data, acquired by the AisaOWL sensor over Nitzana National Park in Israel, were used to demonstrate how LWIR region data can be used to map quartz content on the soil surface in a pixel-by-pixel process. The LWIR radiance image is composed of the surface emissivity (and hence the surface's chemical and physical properties), the radiant temperature (according to the Plank equation) and the atmospheric attenuation (which is different during the day and at night). In this work, we show that it is possible to separate surface emissivity, temperature and atmospheric attenuation by using the radiance measured from a vicarious calibration site which was found to be distinctive for the atmospheric contribution. Applying the spectrum of this area as a gain factor to each pixel in the image reduced the atmospheric effects while emphasizing the mineralogical features. Based on this finding and using the same vicarious calibration site used by Notesco et al. (2015), we further studied the possibility of mapping quartz in an area outside the vicarious calibration site. The resulting emissivity image of Nitzana soils (100 km away from the vicarious calibration site) enabled quantifying the quartz in each pixel and mapping its abundance. The day and night images showed a similar quartz distribution, thereby validating the methodology and

  11. The design of a multi-detector spectrometer for the infrared. [satellite-borne atmospheric temperature sounder

    NASA Technical Reports Server (NTRS)

    Koch, D. G.; Aubrecht, J. A.

    1978-01-01

    A modified Ebert-Fastie spectrometer has been developed for atmospheric temperature sounding applications. The device is described with reference to its resolution, grating, focal-length mirror, mirror, equivalent f-number, and projected area of grating. The images of the entrance slit appear tilted backwards away from the concave mirror. Astigmatism and spherical aberration are reduced by asperizing the mirror. The resolution and f-number of the instrument are limited by the sagittal coma. The orientation and size of the exit slit are functions of wavelength.

  12. Feasibility of modifying the high resolution infrared radiation sounder (HIRS/2) for measuring spectral components of Earth radiation budget

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.; Holman, K. A.

    1980-01-01

    The concept of adding four spectral channels to the 20 channel HIRS/2 instrument for the purpose of determining the origin and profile of radiant existence from the Earth's atmosphere is considered. Methods of addition of three channels at 0.5, 1.0 and 1.6 micron m to the present 0.7 micron m visible channel and an 18-25 micron m channel to the present 19 channels spaced from 3.7 micron m to 15 micron m are addressed. Optical components and physical positions were found that permit inclusion of these added channels with negligible effect on the performance of the present 20 channels. Data format changes permit inclusion of the ERB data in the 288 bits allocated to HIRS for each scan element. A lamp and collimating optic assembly may replace one of the on board radiometric black bodies to provide a reference source for the albedo channels. Some increase in instrument dimensions, weight and power will be required to accommodate the modifications.

  13. Derivation of Tropospheric Carbon Dioxide and Methane Concentrations in the Boreal Zone from Satellite High Resolution Infrared Sounders Data

    NASA Astrophysics Data System (ADS)

    Uspensky, Alexander; Camy-Peyret, Claude; Rublev, Alexey; Kukharsky, Alexander; Romanov, Sergey

    2009-03-01

    The presentation describes the approach developed for clear-sky or cloud-cleared AIRS data inversion and retrieval of the atmospheric column-average carbon dioxide mixing ratio QCO2. Its efficiency is demonstrated in the validation effort carried out with real AIRS data for two areas in the boreal zone of Western Siberia. To retrieve the methane column amount CACH4, the original method has been proposed based on the inversion of clear-sky IASI data in four dedicated super- channels or AIRS data in eight channels. The performance of CACH4 retrieval algorithms is evaluated in a case study experiment involving datasets of real IASI and AIRS measurements (Esrange/Kiruna, Sweden).

  14. Four Years of Absolutely Calibrated Hyperspectral Data from the Atmospheric Infrared Sounder (AIRS) on the Eos Aqua

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Broberg, Steve; Elliott, Denis; Gregorich, Dave

    2006-01-01

    This viewgraph presentation reviews four years of absolute calibration of hyperspectral data from the AIRS instrument located on the EOS AQUA spacecraft. The following topics are discussed: 1) A quick overview of AIRS; 2) What absolute calibration accuracy and stability are required for climate applications?; 3) Validating of radiance accuracy and stability: Results from four years of AIRS data; and 4) Conclusions.

  15. An Instrument Concept for Atmospheric Infrared Sounding from Medium Earth Orbit

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Baron, Richard l.

    2004-01-01

    Medium Earth Orbit (MEO) offers a unique vantage point for atmospheric infrared sounding. The orbit allows the entire globe to be covered each day with one satellite. The orbit is slow enough to allow multiple views of a single target to be made on each pass. this paper discusses the advantages in coverage and revisit rate from MEO for a particular concept for a Medium Earth Orbit Infrared Atmospheric Sounder (MIRIS). The requirements for this instrument in terms of spectral range, spatial resolution, field of view, and calibration are presented as well as the radiometric performance expectations.

  16. WindSat Soil Moisture and Vegetation Validation and Performance Prediction for the NPOESS Microwave Imager/Sounder (MIS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The National Polar-orbiting Operational Environmental Satellite System’s (NPOESS) Microwave Imager/Sounder (MIS) instrument is in development, with soil moisture sensing depth as one of the two Key Performance Parameters (KPPs). The other one is ocean surface wind speed precision. Based on the curre...

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

    NASA Technical Reports Server (NTRS)

    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).

  18. Lunar radar sounder observations of subsurface layers under the nearside maria of the Moon

    NASA Astrophysics Data System (ADS)

    Kumamoto, A.; Ono, T.; Nakagawa, H.; Yamaguchi, Y.; Oshigami, S.; Yamaji, A.; Kobayashi, T.; Kasahara, Y.; Oya, H.

    2008-12-01

    The Lunar Radar Sounder (LRS) on-board the Kaguya (SELENE) spacecraft started the lunar surface and subsurface soundings since November 2007 in order to understand the origin and evolution of the Moon. Kaguya is in circular orbit with an altitude of 100 km and an inclination of 90 degrees. Orbital period is about 2 hours. The LRS system transmits a radar signal modulated from 4 MHz to 6 MHz with a pulse width of 200 microsecond and a peak power of about 800 Watts. The range resolution of LRS is 75 m in free space. The pulse repetition frequency of pulse transmission is 20Hz (Ono and Oya, 2000; Ono et al., 2008). After the operation for 10 month, the radar sounder observation covered almost whole area of the lunar surface. Based on the observations performed by Apollo Lunar Sounder Experiment (ALSE), it was reported that there are two reflectors at depths of ~1km and ~2km, or apparent depths of ~3km and ~6km, in Mare Serenitatis (Peeples et al., 1978). Therefore, we have checked LRS data obtained in Mare Serenitatis. However, we could not find such reflectors in the LRS data. Instead, we have discovered prominent reflectors lying at the apparent depths of a few hundred meters. Because the range resolution of ALSE was ~400 m, or ~1200 m in free space, it could not distinguish shallow reflectors as found by LRS. It should be noted that similar peak structures can be also formed by range sidelobes of surface echoes. However, we can conclude the peaks seen in the LRS data are not by range sidelobes. If they are sidelobes, (i) the power ratio of range sidelobe to mainlobe should be constant and (ii) the frequency offset of range sidelobe from mainlobe should also be constant. Neither of them is true in the LRS data. The comparison of B-scan images along parallel orbits also supports the conclusion. We also found that most of neaside maria have subsurface stratifications at depths of several hundred meters as seen in Mare Selenitatis. It suggests that they are common

  19. High-Power Radar Sounders for the Investigation of Jupiter Icy Moons

    NASA Technical Reports Server (NTRS)

    Safaeinili, A.; Ostro, S.; Rodriquez, E.; Blankenship, D.; Kurth, W.; Kirchner, D.

    2005-01-01

    The high power and high data rate capability made available by a Prometheus class spacecraft could significantly enhance our ability to probe the subsurface of the planets/moons and asteroid/comets. The main technology development driver for our radar is the proposed Jupiter Icy Moon Orbiter (or JIMO) mission due to its harsh radiation environment. We plan to develop a dual-band radar at 5 and 50 MHz in response to the two major science requirements identified by the JIMO Science Definition Team: studying the near subsurface (less than 2 km) at high resolution and detection of the ice/ocean interface for Europa (depth up to 30 km). The 50-MHz band is necessary to provide high spatial resolution (footprint and depth) as required by the JIMO mission science requirements as currently defined. Our preliminary assessment indicates that the 50-MHz system is not required to be as high-power as the 5-MHz system since it will be more limited by the surface clutter than the Jupiter or galactic background noise. The low frequency band (e.g. 5 MHz), which is the focus of this effort, would be necessary to mitigate the performance risks posed by the unknown subsurface structure both in terms of unknown attenuation due to volumetric scattering and also the detection of the interface through the attenuative transition region at the ice/ocean interface. Additionally, the 5-MHz band is less affected by the surface roughness that can cause loss of coherence and clutter noise. However, since the Signal-to-Noise-Ratio (SNR) of the 5-MHz radar band is reduced due to Jupiter noise when operating in the Jupiter side of the moon, it is necessary to increase the radiated power. Our challenge is to design a high-power HF radar that can hnction in Jupiter's high radiation environment, yet be able to fit into spacecraft resource constraints such as mass and thermal limits. Our effort to develop the JIMO radar sounder will rely on our team's experience with planetary radar sounder design

  20. Infrared source test

    SciTech Connect

    Ott, L.

    1994-11-15

    The purpose of the Infrared Source Test (IRST) is to demonstrate the ability to track a ground target with an infrared sensor from an airplane. The system is being developed within the Advance Technology Program`s Theater Missile Defense/Unmanned Aerial Vehicle (UAV) section. The IRST payload consists of an Amber Radiance 1 infrared camera system, a computer, a gimbaled mirror, and a hard disk. The processor is a custom R3000 CPU board made by Risq Modular Systems, Inc. for LLNL. The board has ethernet, SCSI, parallel I/O, and serial ports, a DMA channel, a video (frame buffer) interface, and eight MBytes of main memory. The real-time operating system VxWorks has been ported to the processor. The application code is written in C on a host SUN 4 UNIX workstation. The IRST is the result of a combined effort by physicists, electrical and mechanical engineers, and computer scientists.

  1. Germanium blocked impurity band far infrared detectors

    NASA Astrophysics Data System (ADS)

    Rossington, Carolyn Sally

    1988-04-01

    The infrared portion of the electromagnetic spectrum has been of interest to scientist since the eighteenth century when Sir William Herschel discovered the infrared as he measured temperatures in the sun's spectrum and found that there was energy beyond the red. In the late nineteenth century, Thomas Edison established himself as the first infrared astronomer to look beyond the solar system when he observed the star Arcturus in the infrared. Significant advances in infrared technology and physics, long since Edison's time, have resulted in many scientific developments, such as the Infrared Astronomy Satellite (IRAS) which was launched in 1983, semiconductor infrared detectors for materials characterization, military equipment such as night-vision goggles and infrared surveillance equipment. It is now planned that cooled semiconductor infrared detectors will play a major role in the Star Wars nuclear defense scheme proposed by the Reagan administration.

  2. Germanium blocked impurity band far infrared detectors

    SciTech Connect

    Rossington, C.S.

    1988-04-01

    The infrared portion of the electromagnetic spectrum has been of interest to scientist since the eighteenth century when Sir William Herschel discovered the infrared as he measured temperatures in the sun's spectrum and found that there was energy beyond the red. In the late nineteenth century, Thomas Edison established himself as the first infrared astronomer to look beyond the solar system when he observed the star Arcturus in the infrared. Significant advances in infrared technology and physics, long since Edison's time, have resulted in many scientific developments, such as the Infrared Astronomy Satellite (IRAS) which was launched in 1983, semiconductor infrared detectors for materials characterization, military equipment such as night-vision goggles and infrared surveillance equipment. It is now planned that cooled semiconductor infrared detectors will play a major role in the ''Star Wars'' nuclear defense scheme proposed by the Reagan administration.

  3. Advanced methods for preparation and characterization of infrared detector materials. [crystallization and phase diagrams of Hg sub 1-x Cd sub x Te

    NASA Technical Reports Server (NTRS)

    Lehoczy, S. L.

    1979-01-01

    Crystal growth of Hg sub 1-x Cd sub x Te and density measurements of ingot slices are discussed. Radial compositional variations are evaluated from the results of infrared transmission edge mapping. The pseudo-binary HgTe-CdTe phase diagram is examined with reference to differential thermal analysis measurements. The phase equilibria calculations, based on the 'regular association solution' theory (R.A.S.) are explained and, using the obtained R.A.S. parameters, the activities of Hg, Cd, and Te vapors and their partial pressures over the pseudo-binary melt are calculated.

  4. Navigation Signal Disturbances by Multipath Propagation - Scaled Measurements with a Universal Channel Sounder Architecture

    NASA Astrophysics Data System (ADS)

    Geise, Robert; Neubauer, Bjoern; Zimmer, Georg

    2015-11-01

    The performance of navigation systems is always reduced by unwanted multipath propagation. This is especially of practical importance for airborne navigation systems like the instrument landing system (ILS) or the VHF omni directional radio range (VOR). Nevertheless, the quantitative analysis of corresponding, potentially harmful multipath propagation disturbances is very difficult due to the large parameter space. Experimentally difficulties arise due to very expensive, real scale measurement campaigns and numerical simulation techniques still have shortcomings which are briefly discussed. In this contribution a new universal approach is introduced on how to measure very flexibly multipath propagation effects for arbitrary navigation systems using a channel sounder architecture in a scaled measurement environment. Two relevant scenarios of multipath propagation and the impact on navigation signals are presented. The first describes disturbances of the ILS due to large taxiing aircraft. The other example shows the influence of rotating wind turbines on the VOR.

  5. Tropical cyclone track and genesis forecasting using satellite microwave sounder data

    NASA Technical Reports Server (NTRS)

    Kidder, S. Q.

    1982-01-01

    Although many dynamical and statistical prediction schemes are available to forecasters, tropical cyclone track errors are still large. One primary difficulty is that tropical cyclones exist over the data-sparse tropical oceans. Satellite sounders, however, routinely provide numerous data over these areas. Mean layer temperatures from the Scanning Microwave Spectrometer on board the Nimbus 6 satellite are decomposed using empirical orthogonal functions, and the expansion coefficients are related to deviations from the persistence forecast location, to speed change, to direction change and to intensity change. The significance of the regression equations is tested by a null hypothesis of zero correlation coefficient. It appears that significant information about tropical cyclone motion exists in the satellite-estimated mean layer temperatures, especially at upper levels. A physical interpretation of the statistical results is offered, and a one-storm-out independent test is used to test the stability of the equations. Finally, some further work is suggested.

  6. Microwave Limb Sounder/El Nino Watch - February thru December, 1997

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This series of six images shows the movement of atmospheric water vapor over the Pacific Ocean during the formation of the 1997 El Nino condition. Higher than normal ocean water temperatures increase the rate of evaporation and the resulting warm moist air rises into the atmosphere altering global weather patterns. Data obtained by the Microwave Limb Sounder (MLS) on NASA's Upper Atmosphere Research Satellite (UARS), from late February 1997 to late December 1997, show the movement from the western Pacific to the eastern Pacific of high levels of water vapor (red) at 10 kilometers (6 miles) above the surface. Areas of unusually drier air (blue) appear over Indonesia. December 1997 data also show a rapid increase of water vapor off the coast of South America, the result of very high water temperatures in that region.

  7. Microwave Sounder for GEOS-R - A GeoSTAR Progress Report

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn H.; Wilson, William; Tanner, Alan; Kangaslahti, Pekka P.

    2005-01-01

    The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a new concept for a microwave sounder, intended to be deployed on NOAA's next generation of geostationary weather satellites, GOES-R. A ground based prototype has been developed at the Jet Propulsion Laboratory, under NASA Instrument Incubator Program sponsorship, and is now undergoing tests and performance characterization. The initial space version of GeoSTAR will have performance characteristics equal to those of the AMSU system currently operating on polar orbiting environmental satellites, but subsequent versions will significantly outperform AMSU. In addition to all-weather temperature and humidity soundings, GeoSTAR will also provide continuous rain mapping, tropospheric wind profiling and real time storm tracking.

  8. Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 3: Project cost estimates

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The laser atmospheric wind sounder (LAWS) cost modeling activities were initiated in phase 1 to establish the ground rules and cost model that would apply to both phase 1 and phase 2 cost analyses. The primary emphasis in phase 1 was development of a cost model for a LAWS instrument for the Japanese Polar Orbiting Platform (JPOP). However, the Space Station application was also addressed in this model, and elements were included, where necessary, to account for Space Station unique items. The cost model presented in the following sections defines the framework for all LAWS cost modeling. The model is consistent with currently available detail, and can be extended to account for greater detail as the project definition progresses.

  9. On the assimilation of satellite sounder data in cloudy skies in numerical weather prediction models

    NASA Astrophysics Data System (ADS)

    Li, Jun; Wang, Pei; Han, Hyojin; Li, Jinlong; Zheng, Jing

    2016-04-01

    Satellite measurements are an important source of global observations in support of numerical weather prediction (NWP). The assimilation of satellite radiances under clear skies has greatly improved NWP forecast scores. However, the application of radiances in cloudy skies remains a significant challenge. In order to better assimilate radiances in cloudy skies, it is very important to detect any clear field-of-view (FOV) accurately and assimilate cloudy radiances appropriately. Research progress on both clear FOV detection methodologies and cloudy radiance assimilation techniques are reviewed in this paper. Overview on approaches being implemented in the operational centers and studied by the satellite data assimilation research community is presented. Challenges and future directions for satellite sounder radiance assimilation in cloudy skies in NWP models are also discussed.

  10. EOS Microwave Limb Sounder Observations of the Antarctic Polar Vortex Breakup in 2004

    NASA Technical Reports Server (NTRS)

    Manney, G. L.; Santee, M. L.; Livesey, N. J.; Froidevaux, L.; Read, W. G.; Pumphrey, H. C.; Waters, J. W.; Pawson, S.

    2005-01-01

    Observations from the Microwave Limb Sounder (MLS) on NASA's new Aura satellite give an unprecedentedly detailed picture of the spring Antarctic polar vortex breakup throughout the stratosphere. HCl is a particularly valuable tracer in the lower stratosphere after chlorine deactivation. MLS HCl, N2O, H2O broke up in the upper stratosphere by early October, in the midstratosphere by early November, and in the lower stratosphere by late December. The subvortex broke up just a few days later than the lower stratospheric vortex. Vortex remnants persisted in the midstratosphere through December, but only through early January 2005 in the lower stratosphere. MLS N2O observations show diabatic descent continuing throughout November, with evidence of weak ascent after late October in the lower stratospheric vortex core.

  11. Preliminary Regional Analysis of the Kaguya Lunar Radar Sounder (LRS) Data through Eastern Mare Imbrium

    NASA Technical Reports Server (NTRS)

    Cooper, B.L.; Antonenko, I.; Yamaguchi, Y.; Osinski, G.; Ono, T.; Ku-mamoto, A.

    2009-01-01

    The Lunar Radar Sounder (LRS) experiment on board the Kaguya spacecraft is observing the subsurface structure of the Moon, using ground-penetrating radar operating in the frequency range of 5 MHz [1]. Because LRS data provides in-formation about lunar features below the surface, it allows us to improve our understanding of the processes that formed the Moon, and the post-formation changes that have occurred (such as basin formation and volcanism). We look at a swath of preliminary LRS data, that spans from 7 to 72 N, and from 2 to 10 W, passing through the eastern portion of Mare Imbrium (Figure 1). Using software, designed for the mineral exploration industry, we produce a preliminary, coarse 3D model, showing the regional structure beneath the study area. Future research will involve smaller subsets of the data in regions of interest, where finer structures, such as those identified in [2], can be studied.

  12. A statistical evaluation and comparison of VISSR Atmospheric Sounder (VAS) data and corresponding rawinsonde measurements

    NASA Technical Reports Server (NTRS)

    Jedlovec, G. J.

    1984-01-01

    The mesoscale accuracy of GOES Visible/IR Spin-Scan-Radiometer (VISSR) Atmospheric Sounder (VAS) temperature profiles and mean-precipitable-water measurements obtained over central Texas on March 6, 1982, is evaluated on the basis of comparing them with three-hourly rawinsonde data (up to 100 mbar) of similar spatial resolution for the same area and time. The VAS data comprise three sets: physical retrievals by the method of Smith (1970), modified physical retrievals by the method of Smith (1983), and regression soundings (incorporating some rawinsonde data) by the method of Lee et al. (1983). The data are presented graphically, and all three VAS data sets are found to have similar temperature biases, which vary from hot to cold with altitude and are apparently related to major inversions. Systematic moisture biases are seen in the physical and modified physical data sets, while the regression soundings are relatively unbiased but do not accurately reproduce moisture gradients seen in the rawinsonde data.

  13. Calibration of the Microwave Limb Sounder on the Upper Atmosphere Research Satellite

    NASA Technical Reports Server (NTRS)

    Jarnot, R. F.; Cofield, R. E.; Waters, J. W.; Flower, D. A.; Peckham, G. E.

    1996-01-01

    The Microwave Limb Sounder (MLS) is a three-radiometer, passive, limb emission instrument onboard the Upper Atmosphere Research Satellite (UARS). Radiometric, spectral and field-of-view calibrations of the MLS instrument are described in this paper. In-orbit noise performance, gain stability, spectral baseline and dynamic range are described, as well as use of in-flight data for validation and refinement of prelaunch calibrations. Estimated systematic scaling uncertainties (3 sigma) on calibrated limb radiances from prelaunch calibrations are 2.6% in bands 1 through 3, 3.4% in band 4, and 6% in band 5. The observed systematic errors in band 6 are about 15%, consistent with prelaunch calibration uncertainties. Random uncertainties on individual limb radiance measurements are very close to the levels predicted from measured radiometer noise temperature, with negligible contribution from noise and drifts on the regular in-flight gain calibration measurements.

  14. The Laser Atmospheric Wind Sounder (LAWS) Phase 2 Preliminary Laser Design

    NASA Technical Reports Server (NTRS)

    Lawrence, T. Rhidian; Pindroh, Albert L.; Bowers, Mark S.; Dehart, Terence E.; Mcdonald, Kenneth F.; Cousins, Ananda; Moody, Stephen E.

    1992-01-01

    The requirements for the Laser Atmospheric Wind Sounder (LAWS) were determined from system considerations and are summarized in tabular form. The laser subsystem provides for the generation and frequency control of two beams, the transmit high power and local oscillator beams, which are delivered to the optical and receiver subsystems, respectively. In our baseline approach, the excitation of the gain section is achieved by a self-sustaining uv-(corona) preionized discharge. Gas is recirculated within the laser loop using a transverse flow fan. An intra-flow-loop heat exchanger, catalyst monolith, and acoustic attenuators condition the gas to ensure uniform energy output and high beam quality during high pulse repetition rate operation. The baseline LAWS laser pulse temporal profile as calculated by in-house laser codes is given in graphical form.

  15. Synthetic aperture technique applied to a multi-beam echo sounder

    NASA Astrophysics Data System (ADS)

    Asada, Akira; Yabuki, Tetsuichiro

    2001-04-01

    We are developing a synthetic aperture technique using a Sea Beam 2000 multi-beam echo sounder to observe subsea crustal movements for earthquake studies. Augmented by the Kinematic GPS and a motion sensor, the synthetic aperture technique was successfully applied to the Sea Beam 2000 with a 12 kHz frequency acoustic signal. The 4.3-meter long projector produces a transmission fan beam in alongtrack beamwidth of 2 degrees, but a synthesis of the data achieved about 37 m aperture length, equivalent to a 0.3 degrees alongtrack beamwidth. Bathymetry measurements at the water depth of 900 m obtained through the synthetic aperture processing show considerable improvement of the signal-to-noise ratio and reveal detailed features of the seafloor.

  16. Feasibility Study of Graphite Epoxy Antenna for a Microwave Limb Sounder Radiometer (MLSR)

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Results are presented of a feasibility study to design graphite epoxy antenna reflectors for a jet propulsion laboratory microwave limb sounder instrument (MLSR). Two general configurations of the offset elliptic parabolic reflectors are presented that will meet the requirements on geometry and reflector accuracy. The designs consist of sandwich construction for the primary reflectors, secondary reflector support structure and cross-tie members between reflector pairs. Graphite epoxy materials of 3 and 6 plies are used in the facesheets of the sandwich. An aluminum honeycomb is used for the core. A built-in adjustment system is proposed to reduce surface distortions during assembly. The manufacturing and environmental effects are expected to result in surface distortions less than .0015 inch and pointing errors less than .002 degree.

  17. Development of a global backscatter model for NASA's laser atmospheric wind sounder

    NASA Technical Reports Server (NTRS)

    Bowdle, David; Collins, Laurie; Mach, Douglas; Mcnider, Richard; Song, Aaron

    1992-01-01

    During the Contract Period April 1, 1989, to September 30, 1992, the Earth Systems Science Laboratory (ESSL) in the Research Institute at the University of Alabama in Huntsville (UAH) conducted a program of basic research on atmospheric backscatter characteristics, leading to the development of a global backscatter model. The ESSL research effort was carried out in conjunction with the Earth System Observing Branch (ES43) at the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center, as part of NASA Contract NAS8-37585 under the Atmospheric Dynamics Program at NASA Headquarters. This research provided important inputs to NASA's GLObal Backscatter Experiment (GLOBE) program, especially in the understanding of global aerosol life cycles, and to NASA's Doppler Lidar research program, especially the development program for their prospective space-based Laser Atmospheric Wind Sounder (LAWS).

  18. The Impact of Upper Tropospheric Humidity from Microwave Limb Sounder on the Midlatitude Greenhouse Effect

    NASA Technical Reports Server (NTRS)

    Hu, Hua; Liu, W. Timothy

    1998-01-01

    This paper presents an analysis of upper tropospheric humidity, as measured by the Microwave Limb Sounder, and the impact of the humidity on the greenhouse effect in the midlatitudes. Enhanced upper tropospheric humidity and an enhanced greenhouse effect occur over the storm tracks in the North Pacific and North Atlantic. In these areas, strong baroclinic activity and the large number of deep convective clouds transport more water vapor to the upper troposphere, and hence increase greenhouse trapping. The greenhouse effect increases with upper tropospheric humidity in areas with a moist upper troposphere (such as areas over storm tracks), but it is not sensitive to changes in upper tropospheric humidity in regions with a dry upper troposphere, clearly demonstrating that there are different mechanisms controlling the geographical distribution of the greenhouse effect in the midlatitudes.

  19. Using lunar sounder imagery to distinguish surface from subsurface reflectors in lunar highlands areas

    NASA Technical Reports Server (NTRS)

    Cooper, Bonnie L.; Carter, James L.

    1993-01-01

    We have developed a method using the Apollo 17 Lunar Sounder imagery data which appears capable of filtering out off-nadir surface noise from highland area profiles, so that subsurface features may now be detected in highland areas as well as mare areas. Previously, this had been impossible because the rough topography in the highland areas created noise in the profiles which could not be distinguished from subsurface echoes. The new method is an image processing procedure involving the computerized selection of pixels which represent intermediate echo intensity values, then manually removing those pixels from the profile. Using this technique, a subsurface feature with a horizontal extent of about 150 km, at a calculated depth of approximately 3 km, has been detected beneath the crater Riccioli in the highlands near Oceanus Procellarum. This result shows that the ALSE data contain much useful information that remains to be extracted and used.

  20. Microwave Limb Sounder Measurements Depicting the Relationship Between Nitrous Oxide Levels and

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Aura's Microwave Limb Sounder measures nitrous oxide, which is unaffected by stratospheric chemical processes. By studying changes in its levels, scientists can better understand how air is moving around and how ozone is affected by that air motion, allowing them to differentiate those changes from the ones caused by chemical ozone destruction. In these cross-sections of nitrous oxide (top) and ozone (bottom) data from Aura, changes in the levels of these two chemicals at various temperatures and latitudes are depicted over time. The white contour shows the approximate location of the polar vortex boundary.

    The left panel data were collected on January 23, 2005, near the beginning of chemical ozone destruction this winter. Virtually all chemical loss occurred before March 10 (center panel). Ozone destruction extended throughout the polar vortex from about 15-20 kilometers (9-13 miles), but occurred only in the outer part of the vortex from 20-25 kilometers (13-16 miles). The differences between the two days are depicted in the right panel. The largest observed difference is about a 1.2 parts per million by volume decrease in ozone. Plots of nitrous oxide show a decrease in the region in the outer part of the vortex where most ozone loss occurs, indicating that air from above (where nitrous oxide is lower) has moved into this region. This downward motion brings higher ozone into the region where chemical loss is occurring, thus partially masking the effects of chemical loss. Calculations using Microwave Limb Sounder data to separate dynamical and chemical effects indicate maximum chemical ozone loss of approximately 2 parts per million by volume (approximately 60 percent) in the outer part of the vortex near 18-21 kilometers (11-13 miles), and approximately 1.5 parts per million by volume when averaged throughout the whole vortex region.

  1. Observation capability of Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) from International Space Station

    NASA Astrophysics Data System (ADS)

    Kasai, Yasuko; Tanaka, Takahiro; Dupuy, Eric; Kita, Kazuyuki; Baron, Philippe; Ochiai, Satoshi; Nishibori, Toshiyuki; Kikuchi, Kenichi; Mendrok, Jana; Murtagh, Donal P.; Urban, Joachim; Smiles Mission Team

    A new generation of sub-millimeter-wave receivers employing sensitive SIS (Superconductor-Insulator-Superconductor) detector technology will provide new opportunities for precise pas-sive remote sensing observation of minor constituents in atmosphere. Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) had been launched in September 11, 2009 and installed to the Japanese Experiment Module (JEM) on the International Space Station (ISS). SMILES is a collaboration project of National Institute of Information and Communications Technology (NICT) and Japan Aerospace Exploration Agency (JAXA). Mission objectives of SMILES are: 1. Space demonstration of super-sensitive SIS mixer and 4-K mechanical cooler technology 2. Super-sensitive global observation of atmospheric minor constituents with sub-millimeter-wave limb emission sounder JEM/SMILES will allow to observe the atmospheric species such as O3, H35Cl, H37Cl, ClO, HO2, BrO, HOCl, HOBr, HNO3, CH3CN, Ozone isotope species, H2O, and Ice Cloud with the precisions in a few to several tens percents. The altitude region of observation is from the upper troposphere to the mesopouse. We performed the early comparison/validation of ozone with 4 satellites measurements, AURA/MLS, Odin/SMR, ACE, and Odin/OSIRIS, and ozonesonde. SMILES ozone was in good agreement with these data. For example, difference between SMILES and MLS was less than 2 percent be-tween 20-50km. These results are consistent with the observation capabilities of JEM/SMILES with error analysis. This super technology may allow us to open new issues in atmospheric science.

  2. Estimating oil concentration and flow rate with calibrated vessel-mounted acoustic echo sounders

    PubMed Central

    Weber, Thomas C.; De Robertis, Alex; Greenaway, Samuel F.; Smith, Shep; Mayer, Larry; Rice, Glen

    2012-01-01

    As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon-Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson. Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, and weakening with increasing distance out to 5,000 m. Similar high-volume scattering anomalies were not observed at 12 or 38 kHz, although observations of anomalously low-volume scattering strength were made in the deep scattering layer at these frequencies at approximately the same locations. Together with observations of ocean currents, the acoustic observations are consistent with a rising plume of small (< 1-mm radius) oil droplets. Using simplistic but reasonable assumptions about the properties of the oil droplets, an estimate of the flow rate was made that is remarkably consistent with those made at the wellhead by other means. The uncertainty in this acoustically derived estimate is high due to lack of knowledge of the size distribution and rise speed of the oil droplets. If properly constrained, these types of acoustic measurements can be used to rapidly estimate the flow rate of oil reaching the surface over large temporal and spatial scales. PMID:22167799

  3. Estimating oil concentration and flow rate with calibrated vessel-mounted acoustic echo sounders.

    PubMed

    Weber, Thomas C; De Robertis, Alex; Greenaway, Samuel F; Smith, Shep; Mayer, Larry; Rice, Glen

    2012-12-11

    As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon-Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson. Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, and weakening with increasing distance out to 5,000 m. Similar high-volume scattering anomalies were not observed at 12 or 38 kHz, although observations of anomalously low-volume scattering strength were made in the deep scattering layer at these frequencies at approximately the same locations. Together with observations of ocean currents, the acoustic observations are consistent with a rising plume of small (< 1-mm radius) oil droplets. Using simplistic but reasonable assumptions about the properties of the oil droplets, an estimate of the flow rate was made that is remarkably consistent with those made at the wellhead by other means. The uncertainty in this acoustically derived estimate is high due to lack of knowledge of the size distribution and rise speed of the oil droplets. If properly constrained, these types of acoustic measurements can be used to rapidly estimate the flow rate of oil reaching the surface over large temporal and spatial scales.

  4. The High Resolution Dynamics Limb Sounder (HIRDLS) for the Earth Observing System

    SciTech Connect

    Gille, J.; Coffey, M.; Barnett, J.

    1994-12-31

    The HIRDLS instrument is being designed to obtain data to address critical questions related to the middle atmosphere and its role in global change. The authors will briefly state the scientific objectives of the experiment, and then describe the requirements placed on the instrument. These include the ability to obtain measurements with 4{degree} latitudinal and longitudinal resolution, and 1 km vertical resolution, the ability to sound down into the upper troposphere when clouds are absent, and the ability to measure radiance profiles in order to infer temperature and the concentrations of a number of trace species of different chemical lifetimes, along with the gradients of the geopotential height fields, for 5 or more years. The HIRDLS instrument is a multichannel infrared limb scanner that significantly extends the measurement capabilities of earlier instruments such as LIMS and ISAMS. Advances include the use of a two-axis scanner to allow limb scans at multiple azimuths, narrow fields of view coupled with over-sampling, digital filtering and low noise to enhance vertical resolution, the use of larger numbers of channels to acquire data over a larger range of altitudes and the use of a gyroscope to determine motions of the optical bench. The ways in which this will be done will be described. The most demanding requirements are for radiometric accuracy and precision, and for precise pointing knowledge (in the presence of vibration). The results of trade-off studies will be presented, and the current conceptual design will be described.

  5. High-Resolution Dynamics Limb Sounder (HIRDLS) for the Earth Observing System

    NASA Astrophysics Data System (ADS)

    Gille, John C.; Barnett, John J.; Mankin, William G.; Johnson, Brian R.; Dials, Michael; Whitney, John G.; Woodard, Douglas; Arter, Phillip I.; Rudolph, Wayne P.

    1994-09-01

    The HIRDLS instrument is being designed to obtain data to address critical questions related to the middle atmosphere and its role in global change. We briefly state the scientific objectives of the experiment, and then describe the requirements placed on the instrument. These include the ability to obtain measurements with 4 degree(s)latitudinal and longitudinal resolution, and 1 km vertical resolution, the ability to sound down into the upper troposphere when clouds are absent, and the ability to measure radiance profiles in order to infer temperature and the concentrations of a number of trace species of different chemical lifetimes, along with the gradients of the geopotential height fields, for 5 or more years. The HIRDLS instrument is a multichannel infrared limb scanner that significantly extends the measurement capabilities of earlier instruments such as LIMS and ISAMS. Advances include the use of a two-axis scanner to allow limb scans at multiple azimuths, narrow fields of view coupled with over-sampling, digital filtering and low noise to enhance vertical resolution, the use of larger numbers of channels to acquire data over a larger range of altitudes and the use of a gyroscope to determine motions of the optical bench. The ways in which this is done are described. The most demanding requirements are for radiometric accuracy and precision, and for precise pointing knowledge (in the presence of vibration). The results of trade-off studies are presented, and the current conceptual design is described.

  6. Mid-infrared spectroscopic investigation

    NASA Technical Reports Server (NTRS)

    Salisbury, John W.; Vergo, Norma; Walter, Louis

    1987-01-01

    Mid-infrared spectroscopic research efforts are discussed. The development of a new instrumentation to permit advanced measurements in the mid-infrared region of the spectrum, the development of a special library of well-characterized mineral and rock specimens for interpretation of remote sensing data, and cooperative measurements of the spectral signatures of analogues of materials that may be present on the surfaces of asteroids, planets or their Moons are discussed.

  7. Why Infrared?

    ERIC Educational Resources Information Center

    Harris, J. R.

    1973-01-01

    Discusses applications of techniques developed for the remote sensing of infrared radiation. In addition to military applications, remote sensing has become important in collecting environmental data and detecting ecological problems. (JR)

  8. Infrared absorption by volcanic stratospheric aerosols observed by ISAMS

    SciTech Connect

    Grainger, R.G.; Lambert, A.; Taylor, F.W.; Remedios, J.J.; Rodgers, C.D.; Corney, M. ); Kerridge, B.J. )

    1993-06-18

    The upper atmosphere research satellite was lofted shortly after the Mt. Pinatubo volcano erupted, and is estimated to have injected 20 million metric tons of sulphur dioxide into the stratosphere. This gas typically is converted to sulphuric acid by interactions with water droplets in the stratosphere. These droplets are typically not saturated in acid density, so the sticking fraction is very high. The improved stratospheric and mesospheric sounder makes measurements in 14 infrared channels from 4 to 17 [mu]m. The authors have used the available infrared data channels to model the distribution and density of sulfuric acid aerosols in the stratospheric band about the equator as a result of this volcanic eruption. Knowing the spectral properties of the aerosol load will aid in modeling the radiative and climatic impacts of this volcanic ejecta.

  9. Physical Retrieval of Surface Emissivity Spectrum from Hyperspectral Infrared Radiances

    NASA Technical Reports Server (NTRS)

    Li, Jun; Weisz, Elisabeth; Zhou, Daniel K.

    2007-01-01

    Retrieval of temperature, moisture profiles and surface skin temperature from hyperspectral infrared (IR) radiances requires spectral information about the surface emissivity. Using constant or inaccurate surface emissivities typically results in large retrieval errors, particularly over semi-arid or arid areas where the variation in emissivity spectrum is large both spectrally and spatially. In this study, a physically based algorithm has been developed to retrieve a hyperspectral IR emissivity spectrum simultaneously with the temperature and moisture profiles, as well as the surface skin temperature. To make the solution stable and efficient, the hyperspectral emissivity spectrum is represented by eigenvectors, derived from the laboratory measured hyperspectral emissivity database, in the retrieval process. Experience with AIRS (Atmospheric InfraRed Sounder) radiances shows that a simultaneous retrieval of the emissivity spectrum and the sounding improves the surface skin temperature as well as temperature and moisture profiles, particularly in the near surface layer.

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

    SciTech Connect

    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.

  11. Evaluation of Precipitation Detection over Various Surfaces from Passive Microwave Imagers and Sounders

    NASA Technical Reports Server (NTRS)

    Munchak, S. Joseph; Skofronick-Jackson, Gail

    2012-01-01

    During the middle part of this decade a wide variety of passive microwave imagers and sounders will be unified in the Global Precipitation Measurement (GPM) mission to provide a common basis for frequent (3 hr), global precipitation monitoring. The ability of these sensors to detect precipitation by discerning it from non-precipitating background depends upon the channels available and characteristics of the surface and atmosphere. This study quantifies the minimum detectable precipitation rate and fraction of precipitation detected for four representative instruments (TMI, GMI, AMSU-A, and AMSU-B) that will be part of the GPM constellation. Observations for these instruments were constructed from equivalent channels on the SSMIS instrument on DMSP satellites F16 and F17 and matched to precipitation data from NOAA's National Mosaic and QPE (NMQ) during 2009 over the continuous United States. A variational optimal estimation retrieval of non-precipitation surface and atmosphere parameters was used to determine the consistency between the observed brightness temperatures and these parameters, with high cost function values shown to be related to precipitation. The minimum detectable precipitation rate, defined as the lowest rate for which probability of detection exceeds 50%, and the detected fraction of precipitation, are reported for each sensor, surface type (ocean, coast, bare land, snow cover) and precipitation type (rain, mix, snow). The best sensors over ocean and bare land were GMI (0.22 mm/hr minimum threshold and 90% of precipitation detected) and AMSU (0.26 mm/hr minimum threshold and 81% of precipitation detected), respectively. Over coasts (0.74 mm/hr threshold and 12% detected) and snow-covered surfaces (0.44 mm/hr threshold and 23% detected), AMSU again performed best but with much lower detection skill, whereas TMI had no skill over these surfaces. The sounders (particularly over water) benefited from the use of re-analysis data (vs. climatology) to

  12. Overview of the Waveform Capture in the Lunar Radar Sounder on board KAGUYA

    NASA Astrophysics Data System (ADS)

    Kasahara, Y.; Goto, Y.; Hashimoto, K.; Imachi, T.; Kumamoto, A.; Ono, T.; Matsumoto, H.

    2007-12-01

    The Lunar explorer "gKAGUYA"h (SELENE) spacecraft will be launched on September 13, 2007. The Lunar Radar Sounder (LRS) is one of the scientific instruments on board KAGUYA. It consists of three subsystems: the sounder observation (SDR), the natural plasma wave receiver (NPW), and the waveform capture (WFC). The WFC is a high-performance and multifunctional software receiver in which most functions are realized by the onboard software implemented in a digital signal processor (DSP). The WFC consists of a fast-sweep frequency analyzer (WFC-H) covering the frequency range from 1 kHz to 1 MHz and a waveform receiver (WFC-L) in the frequency range from 10 Hz to 100 kHz. The amount of raw data from the plasma wave instrument is huge because the scientific objectives require the covering of a wide frequency range with high time and frequency resolution; furthermore, a variety of operation modes are needed to meet these scientific objectives. In addition, new techniques such as digital filtering, automatic filter selection, and data compression are implemented for data processing of the WFC-L to extract the important data adequately under the severe restriction of total amount of telemetry data. Because of the flexibility of the instruments, various kinds of observation modes can be achieved, and we expect the WFC to generate many interesting data. By taking advantage of a moon orbiter, the WFC is expected to measure plasma waves and radio emissions that are generated around the moon and/or that originated from the sun and from the earth and other planets. One of the phenomena of most interest to be obtained from the WFC data is the dynamics of lunar wake as a result of solar wind-moon interaction. Another scientific topic in the field of lunar plasma physics concerns the minimagnetosphere caused by the magnetic anomaly of the moon. There are various kinds of other plasma waves to be observed from the moon such as Auroral Kilometric Radiation, electrostatic solitary wave

  13. Aura's Microwave Limb Sounder Estimates of Ozone Loss, 2004/2005 Arctic Winter

    NASA Technical Reports Server (NTRS)

    2005-01-01

    These data maps from Aura's Microwave Limb Sounder depict levels of hydrogen chloride (top), chlorine monoxide (center), and ozone (bottom) at an altitude of approximately 19 kilometers (490,000 feet) on selected days during the 2004-05 Arctic winter. White contours demark the boundary of the winter polar vortex.

    The maps from December 23, 2004, illustrate vortex conditions shortly before significant chemical ozone destruction began. By January 23, 2005, chlorine is substantially converted from the 'safe' form of hydrogen chloride, which is depleted throughout the vortex, to the 'unsafe' form of chlorine monoxide, which is enhanced in the portions of the region that receive sunlight at that time of year. Ozone increased over the month as a result of dynamical effects, and chemical ozone destruction is just beginning at this time. A brief period of intense cold a few days later promotes further chlorine activation and consequent changes in hydrogen chloride and chlorine monoxide levels on January 27, 2005. Peak chlorine monoxide enhancement occurs in early February.

    By February 24, 2005, chlorine deactivation is well underway, with chlorine monoxide abundances dropping and hydrogen chloride abundances rising. Almost all chlorine monoxide has been quenched by March 10, 2005. The fact that hydrogen chloride has not fully rebounded to December abundances suggests that some of that chemical was recovered into another chlorine reservoir species.

    Ozone maps for January 27, 2005, through March 10, 2005, show indications of mixing of air from outside the polar vortex into it. Such occurrences throughout this winter, especially in late February and early March, complicate analyses, and detailed calculations are required to rigorously disentangle chemical and dynamical effects and accurately diagnose chemical ozone destruction.

    Based on various analyses of Microwave Limb Sounder data, we estimate that maximum local ozone loss of approximately 2 parts

  14. A Deployable 4 Meter 180 to 680 GHz Antenna for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Cofield, Richard E.; Cohen, Eri J.; Agnes, Gregory S.; Stek, Paul C.; Livesey, Nathaniel J.; Read, William G.; Thomson, Mark W.; Kasl, Eldon

    2011-01-01

    The Scanning Microwave Limb Sounder (SMLS) is a space-borne heterodyne radiometer which will measure pressure, temperature and atmospheric constituents from thermal emission between 180 and 680 GHz. SMLS, planned for the Global Atmospheric Composition Mission of the NRC Decadal Survey, uses a novel toric Cassegrain antenna to perform both elevation and azimuth scanning. These provide better horizontal and temporal resolution and coverage than were possible with elevation-only scanning at typical Low-Earth orbit spacing in the two previous MLS satellite instruments. Development of the SMLS antenna was the focus of a 2006 Small Business Innovative Research (SBIR) program whose phase II culminated in the fabrication and thermal stability testing of a composite demonstration model of the SMLS primary reflector. This reflector has the full 4m height and 1/3 the width planned for flight. An Instrument Incubator Program (IIP) titled "A deployable 4 Meter 180 to 680 GHz antenna for the Scanning Microwave Limb Sounder" continues development of the SMLS antenna with the study of 5 topics: 1) detailed mathematical modeling of the antenna patterns from which we simulate geophysical parameter retrievals in order to establish FOV performance requirements; 2) thorough correlation of finite element model predictions with measurements made on the SBIR reflector. We will again measure deformations of this reflector, under more flight-like thermal gradients, using higher precision metrology techniques available in a new large-aperture facility at JPL; 3) fabrication of a full-width primary reflector whose asbuilt surface figure will better meet the figure requirements of SMLS than did the SBIR reflector; 4) integration of the primary with other reflectors, and with residual front ends built in a 2007 IIP, in a breadboard antenna; and finally 5) RF testing of the breadboard on a Near Field Range at JPL. We report on significant progress in 3 areas of the current IIP: development of

  15. Error Consistency Analysis Scheme for Infrared Ultraspectral Sounding Retrieval Error Budget Estimation

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    Great effort has been devoted towards validating geophysical parameters retrieved from ultraspectral infrared radiances obtained from satellite remote sensors. An error consistency analysis scheme (ECAS), utilizing fast radiative transfer model (RTM) forward and inverse calculations, has been developed to estimate the error budget in terms of mean difference and standard deviation of error in both spectral radiance and retrieval domains. The retrieval error is assessed through ECAS without relying on other independent measurements such as radiosonde data. ECAS establishes a link between the accuracies of radiances and retrieved geophysical parameters. ECAS can be applied to measurements from any ultraspectral instrument and any retrieval scheme with its associated RTM. In this manuscript, ECAS is described and demonstrated with measurements from the MetOp-A satellite Infrared Atmospheric Sounding Interferometer (IASI). This scheme can be used together with other validation methodologies to give a more definitive characterization of the error and/or uncertainty of geophysical parameters retrieved from ultraspectral radiances observed from current and future satellite remote sensors such as IASI, the Atmospheric Infrared Sounder (AIRS), and the Cross-track Infrared Sounder (CrIS).

  16. Infrared target array development

    NASA Astrophysics Data System (ADS)

    Scott, E. A.

    1980-04-01

    The US Army Yuma Proving Ground (USAYPG) was requested to develop and acquire a series of infrared targets with controllable thermal signatures to support the test and evaluation of the Target Acquisition Designation System/Pilot Night Vision System (TADS/PNVS) subsystems of the Advanced Attack Helicopter (AAH) Fire Control System. Prior to this development effort, no capability beyond the use of real-scene targets existed at USAYPG to provide thermally active targets with characteristic signatures in the infrared band. Three targets were acquired: (1) a detection target; (2) a recognition target; and (3) a laser scoring board. It is concluded that design goals were met and the system was delivered in time to perform its function. The system provides sufficient thermal realism and has advanced the state-of-the-art of infrared imaging system test and evaluation. It is recommended that the Field Equivalent Bar Target (FEBT) system be validated as a potential test standard and that environmentally 'hardened' targets be acquired for continued thermal sight testing.

  17. Ultraluminous infrared galaxies

    NASA Technical Reports Server (NTRS)

    Sanders, D. B.; Soifer, B. T.; Neugebauer, G.; Scoville, N. Z.; Madore, B. F.; Danielson, G. E.; Elias, J. H.; Matthews, K.; Persson, C. J.; Persson, S. E.

    1987-01-01

    The IRAS survey of the local universe has revealed the existence of a class of ultraluminous infrared galaxies with L(8 to 1000 micrometer) greater than 10 to the 12th L sub 0 that are slightly more numerous, and as luminous as optically selected quasars at similar redshift. Optical CCD images of these infrared galaxies show that nearly all are advanced mergers. Millimeter wave CO observations indicate that these interacting systems are extremely rich in molecular gas with total H2 masses 1 to 3 x 10 to the 10th power M sub 0. Nearly all of the ultraluminous infrared galaxies show some evidence in their optical spectra for nonthermal nuclear activity. It is proposed that their infrared luminosity is powered by an embedded active nucleus and a nuclear starburst both of which are fueled by the tremendous reservoir of molecular gas. Once these merger nuclei shed their obscuring dust, allowing the AGN to visually dominate the decaying starburst, they become the optically selected quasars.

  18. Infrared Thermometer

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Diatek Corporation, San Diego, CA and the Jet Propulsion Lab developed the Diatek Model 7000 aural thermometer which weighs only eight ounces, and measures temperature in less than two seconds using infrared astronomy technology to measure the amount of infrared energy emitted by the eardrum (the same way temperature of stars and planets is measured). This method avoids contact with mucous membranes, virtually eliminating the possibility of cross infection, and permits temperature measurement of newborn, critically ill, or incapacitated patients. Diatek Corporation was purchased by Welch Allyn Inc. The Diatek Model 7000 is now marketed as SureTemp.

  19. NASA's Advancements in Space-Based Spectrometry Lead to Improvements in Weather Prediction and Understanding of Climate Processes

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Iredell, Lena

    2010-01-01

    AIRS (Atmospheric Infra-Red Sounder), was launched, in conjunction with AMSU-A (Advanced Microwave Sounding Unit-A) on the NASA polar orbiting research satellite EOS (Earth Observing System) Aqua satellite in May 2002 as a next generation atmospheric sounding system. Atmospheric sounders provide information primarily about the vertical distribution of atmospheric temperature and water vapor distribution. This is achieved by measuring outgoing radiation in discrete channels (spectral intervals) which are sensitive primarily to variations of these geophysical parameters. The primary objectives of AIRS/AMSU were to utilize such information in order to improve the skill of numerical weather prediction as well as to measure climate variability and trends. AIRS is a multi-detector array grating spectrometer with 2378 channels covering the spectral range 650/cm (15 microns) to 2660/cm (3.6 microns) with a resolving power (i/a i) of roughly 1200 where a i is the spectral channel bandpass. Atmospheric temperature profile can be determined from channel observations taken within the 15 micron (the long-wave CO2 absorption band) and within the 4.2 micron (the short-wave CO2 absorption band). Radiances in these (and all other) spectral intervals in the infrared are also sensitive to the presence of clouds in the instrument?s field of view (FOV), which are present about 95% of the time. AIRS was designed so as to allow for the ability to produce accurate Quality Controlled atmospheric soundings under most cloud conditions. This was achieved by having 1) extremely low channel noise values in the shortwave portion of the spectrum and 2) a very flat spatial response function within a channel?s FOV. IASI, the high spectral resolution IR interferometer flying on the European METOP satellite, does not contain either of these important characteristics. The AIRS instrument was also designed to be extremely stabile with regard to its spectral radiometric characteristics, which is

  20. The Earth Observing System Microwave Limb Sounder (EOS MLS) on the Aura Satellite

    NASA Technical Reports Server (NTRS)

    Waters, Joe W.; Froidevaux, Lucien; Harwood, Robert S.; Jarnot, Robert F.; Pickett, Herbert M.; Read, William G.; Siegel, Peter H.; Cofield, Richard E.; Filipiak, Mark J.; Flower, Dennis A.; Holden, James R.; Lau, Gary K.; Livesey, Nathaniel J.; Manney, Gloria L; Pumphrey, Hugh C.; Santee, Michelle L.; Wu, Dong L.; Cuddy, David T.; Lay, Richard R.; Loo, Mario S.; Perun, Vincent S.; Schwartz, Michael J.; Stek, Paul C.; Thurstans, Robert P.; Boyles, Mark A.

    2006-01-01

    The Earth Observing System Microwave Limb Sounder measures several atmospheric chemical species (OH, HO2, H2O, O3, HCl, ClO, HOCl, BrO, HNO3, N2O, CO, HCN, CH3CN, volcanic SO2), cloud ice, temperature, and geopotential height to improve our understanding of stratospheric ozone chemistry, the interaction of composition and climate, and pollution in the upper troposphere. All measurements are made simultaneously and continuously, during both day and night. The instrument uses heterodyne radiometers that observe thermal emission from the atmospheric limb in broad spectral regions centered near 118, 190, 240, and 640 GHz, and 2.5 THz. It was launched July 15, 2004 on the National Aeronautics and Space Administration's Aura satellite and started full-up science operations on August 13, 2004. An atmospheric limb scan and radiometric calibration for all bands are performed routinely every 25 s. Vertical profiles are retrieved every 165 km along the suborbital track, covering 82 S to 82 N latitudes on each orbit. Instrument performance to date has been excellent; data have been made publicly available; and initial science results have been obtained.

  1. Plasma wave observation using waveform capture in the Lunar Radar Sounder on board the SELENE spacecraft

    NASA Astrophysics Data System (ADS)

    Kasahara, Yoshiya; Goto, Yoshitaka; Hashimoto, Kozo; Imachi, Tomohiko; Kumamoto, Atsushi; Ono, Takayuki; Matsumoto, Hiroshi

    2008-04-01

    The waveform capture (WFC) instrument is one of the subsystems of the Lunar Radar Sounder (LRS) on board the SELENE spacecraft. By taking advantage of a moon orbiter, the WFC is expected to measure plasma waves and radio emissions that are generated around the moon and/or that originated from the sun and from the earth and other planets. It is a high-performance and multifunctional software receiver in which most functions are realized by the onboard software implemented in a digital signal processor (DSP). The WFC consists of a fast-sweep frequency analyzer (WFC-H) covering the frequency range from 1 kHz to 1 MHz and a waveform receiver (WFC-L) in the frequency range from 10 Hz to 100 kHz. By introducing the hybrid IC called PDC in the WFC-H, we created a spectral analyzer with a very high time and frequency resolution. In addition, new techniques such as digital filtering, automatic filter selection, and data compression are implemented for data processing of the WFC-L to extract the important data adequately under the severe restriction of total amount of telemetry data. Because of the flexibility of the instruments, various kinds of observation modes can be achieved, and we expect the WFC to generate many interesting data.

  2. Aura Microwave Limb Sounder Animation Illustrating the Interaction Between Temperatures and

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This animation created from data from the Microwave Limb Sounder instrument on NASA's Aura spacecraft depicts the complex interaction of chemicals involved in the destruction of ozone during the 2005 Arctic winter. Red is high, blue/purple is low for all chemicals, and data are taken at an altitude of about 19 kilometers (12 miles). As temperatures dip, nitric acid levels drop, indicating the presence of polar stratospheric clouds, which destroy ozone. Levels of hydrogen chloride (the primary 'safe' form of chlorine) are shown dropping, while levels of chlorine monoxide (the primary 'dangerous' form of chlorine that destroys ozone) rise, and ozone is destroyed (ozone levels generally go down after about January 20).

    The animation also illustrates how air motions change ozone levels. Prior to about January 20, ozone levels increase as ozone is transported down from higher altitudes. After that, ozone decreases gradually, and appears to move around on the surface as horizontal air motions change the shape of the polar vortex and move air into and out of it. Since the highest ozone is mostly around the edge of the vortex, this can increase the ozone inside it.

  3. An evaluation and comparison of vertical profile data from the VISSR Atmospheric Sounder (VAS)

    NASA Technical Reports Server (NTRS)

    Jedlovec, G. J.

    1985-01-01

    A statistical evaluation is used to compared vertical profiles of temperature and moisture derived from VISSR Atmospheric Sounder (VAS) with three different algorithms to that of corresponding rawinsonde measurements for a clear cold environment. To account for time and space discrepancies between the data sets, rawinsonde data were adjusted to be representative of the satellite sounding times. Both rawinsonde and satellite sounding data were objectively analyzed onto a mesoscale grid. These grid point values were compared at 50 mb pressure increments from the surface up to 100 mb. The data were analyed for horizontal and vertical structure, representatives of derived parameters, and significant departure (improvement) from the apriori (first guess) information. Results indicate some rather strong temperature and moisture biases exist in the satellite soundings. Temperature biases of 1 to 4 C and dewpoint biases of 2 to 6 C generally occur in layers where strong inversions are present and vary with time as these atmospheric features evolve. The biases also changes as a function retrieval scheme suggesting limitations and restrictions on the applications of the various techniques. Standard temperature deviations range from 1 to 2 C for each retrieval scheme with maximum values around 800 and 400 mb. Derived parameters (precipitable water and thickness) suffer from similar biases, though to a somewhat lesser extent. Gradients of basic and derived parameters are generally weaker but have good horizontal structure where magnitudes of the parameters are relatively strong. Integrated thermal (temperature) and moisture (precipitable water) parameters show mixed results.

  4. An algorithm for retrieval of precipitation using microwave humidity sounder channels around 183 GHz

    NASA Astrophysics Data System (ADS)

    Varma, A. K.; Piyush, D. N.

    2016-05-01

    An algorithm is developed to identify precipitation affected pixels and quantitatively measure the precipitation using Megha-Tropiques humidity sounder (SAPHIR) channels around water vapor absorption line at 183 GHz. Based on observed brightness temperatures at all the six channels of the SAPHIR, a probabilistic rain identification algorithm is proposed. The rain thus identified is subjected to intensive testing using SAPHIR and PR collocated dataset, that showed that false alarm and missing rain is below 0.9 mm/h. Further a radiative transfer simulations supported rain retrieval algorithm is developed that explained a correlation of 0.7 and rmse of 0.81 mm/h. When both precipitation detection and retrieval algorithms are applied the correlation marginally deteriorates but rmse reduces to 0.55 mm/h. Further comparisons are made of monthly, daily and instantaneous rain over different geographical regions from SAPHIR with corresponding rain values from GSMap, TRMM-3B42 V7 and TRMM-TMI/PR, etc. The paper provides details of algorithm development and validation results.

  5. Dynamical and chemical contributions to variability in microwave limb sounder Arctic stratoshperic column ozone

    NASA Technical Reports Server (NTRS)

    Manney, G.; Froidevaux, L.; Sabutis, J. L.; Santee, M. L.; Livesey, N. J.; Waters, J. W.

    2002-01-01

    Analyses of column ozone above 100 hPa (Col100) derived from Upper Atmosphere Research Satellite Microwave Limb Sounder (MLS) data in February/March 1992-1998 show that about half of the interannual variability in Col100 in the Arctic polar vortex in late winter results from interannual variability in chemical loss. A majority of the remainder results from interannual variability in day-to-day dynamical motions including adiabatic warming/cooling and poleward advection of underlying upper tropospheric subtropical air on short timescales, rather than from variations in descent rates and large-scale transport over the winters. The morphology of Col100 from MLS remains very similar to that in the dynamical models even in the years with most chemical ozone loss. The amount and character of day-to-day variability in dynamical models closely follows that in MLS Col100. Although the morphology of and day-to-day variability in Arctic column ozone are controlled by dynamical processes, chemical ozone loss was a major factor in producing both the low values of and the large interannual variability in Arctic column ozone observed during the 1990s.

  6. Space-Time Variations in Water Vapor as Observed by the UARS Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Elson, Lee S.; Read, William G.; Waters, Joe W.; Mote, Philip W.; Kinnersley, Jonathan S.; Harwood, Robert S.

    1996-01-01

    Water vapor in the upper troposphere has a significant impact on the climate system. Difficulties in making accurate global measurements have led to uncertainty in understanding water vapor's coupling to the hydrologic cycle in the lower troposphere and its role in radiative energy balance. The Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite is able to retrieve water vapor concentration in the upper troposphere with good sensitivity and nearly global coverage. An analysis of these preliminary retrievals based on 3 years of observations shows the water vapor distribution to be similar to that measured by other techniques and to model results. The primary MLS water vapor measurements were made in the stratosphere, where this species acts as a conserved tracer under certain conditions. As is the case for the upper troposphere, most of the stratospheric discussion focuses on the time evolution of the zonal mean and zonally varying water vapor. Stratospheric results span a 19-month period and tropospheric results a 36-month period, both beginning in October of 1991. Comparisons with stratospheric model calculations show general agreement, with some differences in the amplitude and phase of long-term variations. At certain times and places, the evolution of water vapor distributions in the lower stratosphere suggests the presence of meridional transport.

  7. SPNDL: A concept for a small satellite Doppler lidar wind sounder

    NASA Technical Reports Server (NTRS)

    Emmitt, G. D.; Sokoloski, M. M.

    1993-01-01

    Given current resources and the technical challenges in developing a full coverage space-based Doppler lidar wind measuring system such as LAWS (Laser Atmospheric Wind Sounder), it is not likely that the science community will have data streams with which to work before the end of this decade. Currently, a 'fast track' demonstration mission is being seriously considered by several U.S. agencies. Such a mission would have as its primary objectives the demonstration of coherent Doppler lidar technology in space and the delivery of wind observations for science algorithm evaluation and development. However, for such a mission to be achieved at modest costs and within a short time frame, deviations from the full system design are required. Simulation models have been developed over the last decade to aide in the design of Doppler lidar missions and to provide simulated data for use in wind computation algorithm development. SWA has used both models to examine some options that might be cost-effective for a demonstration mission. Over the past few months, Simpson Weather Associates has been studying SPNDL (Spinning Platform with a Non-rotating telescope Doppler Lidar), a new concept for Doppler lidar wind observations from space. Science and Technology Corporation has an interest in participating in an engineering and shuttle accommodation study for SPNDL.

  8. An uncertainty model for deep ocean single beam and multibeam echo sounder data

    NASA Astrophysics Data System (ADS)

    Marks, K. M.; Smith, W. H. F.

    2008-12-01

    Comparing single beam and multibeam echo sounder data where surveys overlap we find that: 95% of multibeam measurements are repeatable to within 0.47% of depth; older single beam data can be at least as accurate as multibeam; single beam and multibeam profiles show excellent agreement at full-wavelengths longer than 4 km; archival sounding errors are not Gaussian; 95% of archival soundings in the northwest Atlantic are accurate to within 1.6% of depth; the 95th percentile error is about five times greater in pre-1969 data than in post-1968 data; many of the largest errors are located over large seafloor slopes, where small navigation errors can lead to large depth errors. Our uncertainty model has the form σ 2 = a 2 + ( bz)2 + ( cs)2, where 2 σ is approximately the 95th percentile error, z is the depth, s is the slope, and a, b, c are constants we determine separately for pre-1969 and post-1968 data.

  9. Thermal Stability of a 4 Meter Primary Reflector for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Cofield, Richard E.; Kasl, Eldon P.

    2011-01-01

    The Scanning Microwave Limb Sounder (SMLS) is a space-borne heterodyne radiometer which will measure pressure, temperature and atmospheric constituents from thermal emission in [180,680] GHz. SMLS, planned for the NRC Decadal Survey's Global Atmospheric Composition Mission, uses a novel toric Cassegrain antenna to perform both elevation and azimuth scanning. This provides better horizontal and temporal resolution and coverage than were possible with elevation-only scanning in the two previous MLS satellite instruments. SMLS is diffraction-limited in the vertical plane but highly astigmatic in the horizontal (beam aspect ratio approx. 1:20). Nadir symmetry ensures that beam shape is nearly invariant over plus or minus 65 deg azimuth. A low-noise receiver FOV is swept over the reflector system by a small azimuth-scanning mirror. We describe the fabrication and thermal-stability test of a composite demonstration primary reflector, having full 4m height and 1/3 the width planned for flight. Using finite-element models of reflectors and structure, we evaluate thermal deformations and optical performance for 4 orbital environments and isothermal soak. We compare deformations with photogrammetric measurements made during soak tests in a chamber. The test temperature range exceeds predicted orbital ranges by large factors, implying in-orbit thermal stability of 0.21 micron rms (root mean square)/C, which meets SMLS requirements.

  10. Observing system simulation experiments for the laser atmospheric wind sounder using global spectral model

    NASA Technical Reports Server (NTRS)

    Rohaly, Gregg; Krishnamurti, T. N.

    1991-01-01

    Fundamental to improving the understanding of the total Earth system are increased and improved observations. In the coming decade several spaceborne instrumented platforms will be constructed and implemented. These platforms will, in large, be housing the NASA Earth Observing System (EOS) instrument suite. One of the proposed instruments is a wind profiling system which is currently referred to as the Laser Atmospheric Wind Sounder (LAWS). This instrument will use a CO2 Doppler lidar wind profiler to give wind measurements with a vertical and horizontal resolution which has yet to be seen globally. The LAWS instrument is now a candidate for launch on a NASA EOS-B platform and is fundamental to increasing our understanding of Earth system science. The LAWS data sets will form an integral component of the temporally continuous data base needed for research of the coupled climate systems. This instrument's observations will aid in giving an improved description of the atmospheric circulation, including the transports of energy, momentum, moisture, trace gases, and aerosols. Also, the wind data will be assimilated and used as the initial state for many global forecast models at various operational centers. Results of system simulation experiments are discussed, and future experiments are described.

  11. Design and Implementation of a Mechanical Control System for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Bowden, William

    2011-01-01

    The Scanning Microwave Limb Sounder (SMLS) will use technological improvements in low noise mixers to provide precise data on the Earth's atmospheric composition with high spatial resolution. This project focuses on the design and implementation of a real time control system needed for airborne engineering tests of the SMLS. The system must coordinate the actuation of optical components using four motors with encoder readback, while collecting synchronized telemetric data from a GPS receiver and 3-axis gyrometric system. A graphical user interface for testing the control system was also designed using Python. Although the system could have been implemented with a FPGA-based setup, we chose to use a low cost processor development kit manufactured by XMOS. The XMOS architecture allows parallel execution of multiple tasks on separate threads-making it ideal for this application and is easily programmed using XC (a subset of C). The necessary communication interfaces were implemented in software, including Ethernet, with significant cost and time reduction compared to an FPGA-based approach. For these reasons, the XMOS technology is an attractive, cost effective, alternative to FPGA-based technologies for this design and similar rapid prototyping projects.

  12. Microwave Limb Sounder/El Nino Watch - Water Vapor Measurement, October, 1997

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image shows atmospheric water vapor in Earth's upper troposphere, about 10 kilometers (6 miles) above the surface, as measured by the Microwave Limb Sounder (MLS) instrument flying aboard the Upper Atmosphere Research Satellite. These data collected in early October 1997 indicate the presence of El Nino by showing a shift of humidity from west to east (blue and red areas) along the equatorial Pacific Ocean. El Nino is the term used when the warmest equatorial Pacific Ocean water is displaced toward the east. The areas of high atmospheric moisture correspond to areas of very warm ocean water. Warmer water evaporates at a higher rate and the resulting warm moist air then rises, forming tall cloud towers. In the tropics, the warm water and the resulting tall cloud towers typically produce large amounts of rain. The MLS instrument, developed at NASA's Jet Propulsion Laboratory, measures humidity at the top of these clouds, which are very moist. This rain is now occurring in the eastern Pacific Ocean and has left Indonesia (deep blue region) unusually dry, resulting in the current drought in that region. This image also shows moisture moving north into Mexico, an effect of several hurricanes spawned by the warm waters of El Nino.

  13. Estimation of ice sheet attenuation by using radar sounder and ice core data

    NASA Astrophysics Data System (ADS)

    Ilisei, Ana-Maria; Li, Jilu; Gogineni, Sivaprasad; Bruzzone, Lorenzo

    2016-10-01

    Due to their great impact on the environment and society, the study of the ice sheets has become a major concern of the scientific community. In particular, the estimation of the ice attenuation is crucial since it enables a more precise characterization of the ice and basal conditions. Although such problem has been often addressed in the literature, the assessment of the ice attenuation is subject to several hypotheses and uncertainties, resulting in a wide range of possible interpretations of the properties of the ice. In this paper, we propose a method for constraining the ice attenuation profiles in the vicinity of an ice core by jointly using coincident radar sounder (RS) data (radargrams) and dielectric profile (DEP) data. Radargrams contain measurements of radar reflected power from ice subsurface dielectric discontinuities (layers) on wide areas. DEP data contain ice dielectric permittivity measurements collected at an ice core. The method relies on the detection of ice layers in the radargrams, the estimation of their depth and reflectivity from the DEP data, and the use of the radar equation for the estimation of ice attenuation through the whole ice column and locally at each layer position. The method has been applied to RS and DEP data acquired at the NEEM core site in Greenland. Experimental results confirm the effectiveness of the proposed method.

  14. EOS Microwave Limb Sounder Observations of 'Frozen-in' Anticyclonic Air in Arctic Summer

    NASA Technical Reports Server (NTRS)

    Manney, G. L.; Livesey, N. J.; Jimenez, C. J.; Pumphrey, H. C.; Santee, M. L.; MacKenzie, I. A.; Waters, J. W.

    2006-01-01

    A previously unreported phenomenon, a 'frozen-in' anticyclone (FrIAC) after the 2005 Arctic spring vortex breakup, was discovered in Earth Observing System (EOS) Microwave Limb Sounder (MLS) long-lived trace gas data. A tongue of low-latitude (high-N2O, low-H2O) air was drawn into high latitudes and confined in a tight anticyclone, then advected intact in the summer easterlies through late August. A similar feature in O3 disappeared by early April as a result of chemical processes. The FrIAC was initially advected upright at nearly the same speed at all levels from approx.660 to 1300 K (approx.25-45 km); increasing vertical wind shear after early June tilted the FrIAC and weakened it at higher levels. The associated feature in PV disappeared by early June; transport calculations fail to reproduce the remarkable persistence of the FrIAC, suggesting deficiencies in summer high-latitude winds. The historical PV record suggests that this phenomenon may have occurred several times before. The lack of a persistent signature in O3 or PV, along with its small size and rapid motion, make it unlikely that a FrIAC could have been reliably identified without hemispheric daily longlived trace gas profiles such as those from EOS MLS.

  15. Low-level water vapor fields from the VISSR Atmospheric Sounder (VAS) 'split window' channels

    NASA Technical Reports Server (NTRS)

    Chesters, D.; Uccellini, L. W.; Robinson, W. D.

    1983-01-01

    A simple physical algorithm is presented which calculates the water vapor content of the lower troposphere from the 11 and 12 micron (split window) channels on the VISSR Atmospheric Sounder (VAS) on the Geostationary Operational Environmental Satellites. The algorithm is used to analyze a time series of VAS split window radiances observed at 15 km horizontal resolution over eastern North America during a 12 hr period on 13 July 1981. Results of the color coded images of the derived precipitable water fields are found to show vivid water vapor features whose broad structure and evolution are verified by the radiosonde and surface networks. The satellite moisture fields also show significant mesoscale features and rapid developments which are not resolved by the conventional networks. The VAS split window is determined to clearly differentiate those areas in which water vapor extends over a deep layer and is more able to support convective cells from those areas in which water vapor is confined to a shallow layer and is therefore less able to support convection. It is concluded that the VAS split windows can be used operationally to monitor mesoscale developments in the low-level moisture fields over relatively cloud-free areas of the United States.

  16. Seasonal variation of Martian middle atmosphere tides observed by the Mars Climate Sounder

    NASA Astrophysics Data System (ADS)

    Wu, Zhaopeng; Li, Tao; Dou, Xiankang

    2015-12-01

    The increased local time coverage retrieved from the Mars Climate Sounder on board the Mars Reconnaissance Orbiter enables the direct extraction of thermal tides in the Mars middle atmosphere. Using temperature profiles from Mars years 30 to 32, we studied the latitudinal and seasonal variations in the tides and stationary planetary waves with zonal wave numbers s = 1-3. The amplitude of the migrating diurnal tide exhibits strong semiannual variations in both the equatorial region and the middle latitudes of Southern Hemisphere. The migrating semidiurnal tide (SW2) shows clear semiannual variations in the equatorial region and the middle latitudes of Northern Hemisphere but an annual variation in the Southern Hemisphere. The spatial and temporal correlations between the SW2 amplitude and the density-scaled opacity of both the water ice and dust in the equatorial region may provide a possible explanation for the tidal forcing of SW2. Three Kelvin modes with zonal wave numbers 1-3 (DE1-DE3) have significant seasonal variations in the equatorial region. DE1 appears to have a semiannual variation, whereas DE2 and DE3 have clear annual variations. Herein, for the first time, we have extracted the westward propagating diurnal tide with s = 2 and 3 and semidiurnal tide with s = 1 in the Mars middle atmosphere using observational data. All three waves have asymmetric latitudinal distributions, which should correspond to their possible excitation source, i.e., nonlinear interactions between stationary planetary waves and migrating tides.

  17. The 4-Day Wave as Observed from the Upper Atmosphere Research Satellite Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Allen, D. R.; Stanford, J. L.; Elson, L. S.; Fishbein, E. F.; Froidevaux, L.; Waters, J. W.

    1997-01-01

    The "4-day wave" is an eastward moving quasi-nondispersive feature with period near 4 days occurring near the winter polar stratopause. This paper presents evidence of the 4-day feature in Microwave Limb Sounder (MLS) temperature, geopotential height, and ozone data from the late southern winters of 1992 and 1993. Space-time spectral analyses reveal a double-peaked temperature structure consisting of one peak near the stratopause and another in the lower mesosphere, with an out-of-phase relationship between the two peaks. This double- peaked structure is reminiscent of recent three-dimensional barotropic/baroclinic instability model predictions and is observed here for the first time. The height variation of the 4-day ozone signal is shown to compare well with a linear advective-photochemical tracer model. Negative regions of quasigeostrophic potential vorticity (PV) gradient and positive Eliassen-Palm flux divergence are shown to occur, consistent with instability dynamics playing a role in wave forcing. Spectral analyses of PV derived from MLS geopotential height fields reveal a 4-day signal peaking near the polar stratopause. The three-dimensional structure of the 4-day wave resembles the potential vorticity "charge" concept, wherein a PV anomaly in the atmosphere (analogous to an electrical charge in a dielectric material) induces a geopotential field, a vertically oriented temperature dipole, and circulation about the vertical axis.

  18. A species classifier of sea creatures compiled on the basis of their echo sounder signals.

    PubMed

    Giryn, A

    1982-06-01

    Species recognition of sea creatures is very important and is still a difficult task in the assessment of oceanic biological resources by hydroacoustic methods and in optimum selective industrial fishing. Trials have shown that recognition by means of the subjective estimation of echo sounder records and sample hauls is not yet fully satisfactory [1]. In this correspondence a classifier of sea creature species is described. The essential efforts have been made to find efficient procedure of distinguishing features selection. As a result the classifier operates on the basis of an observation vector whose components have been developed in a special way. These components are the central moments of consecutive samples of a few realizations of echo signal envelopes. From the point of view of the observation vector, the classifier is based on simple linear theory. In practice the described classifier can be realized with the aid of the rather uncomplicated microprocessor-based circuits. The chosen distinguishing features concem to exceptional complicated nature of the biological targets. Obtained results indicate that the classifier may also be very useful in the recognition of objects belonging to many nonbiological classes.

  19. Riverbed sediment classification using multi-beam echo-sounder backscatter data.

    PubMed

    Amiri-Simkooei, AliReza; Snellen, Mirjam; Simons, Dick G

    2009-10-01

    A method has recently been developed that employs multi-beam echo-sounder backscatter data to both obtain the number of sediment classes and discriminate between them by applying the Bayes decision rule to multiple hypotheses [Simons and Snellen, Appl. Acoust. 70, 1258-1268 (2009)]. In deep water, the number of scatter pixels within the beam footprint is large enough to ensure Gaussian distributions for the backscatter strengths and to increase the discriminative power between acoustic classes. In very shallow water (<10 m), however, this number is too small. This paper presents an extension of this high-frequency methodology for these environments, together with a demonstration of its performance using backscatter data from the river Waal, The Netherlands. The objective of this work is threefold. (i) Increasing the discriminating power of the classification method: high-resolution bathymetry data allow precise bottom slope corrections for obtaining the true incident angle, and the high-resolution backscatter data reduce the statistical fluctuations via an averaging procedure. (ii) Performing a correlation analysis: the dependence of acoustic backscatter classification on sediment physical properties is verified by observing a significant correlation of 0.75 (and a disattenuated correlation of 0.90) between the classification results and sediment mean grain size. (iii) Enhancing the statistical description of the backscatter intensities: angular evolution of the K-distribution shape parameter indicates that the riverbed is a rough surface, in agreement with the results of the core analysis.

  20. Infrared Thermometers

    ERIC Educational Resources Information Center

    Schaefers, John

    2006-01-01

    An infrared (IR) thermometer lab offers the opportunity to give science students a chance to measure surface temperatures, utilizing off-the-shelf technology. Potential areas of study include astronomy (exoplanets), electromagnetic spectrum, chemistry, evaporation rates, anatomy, crystal formation, and water or liquids. This article presents one…

  1. Infrared telescope

    NASA Technical Reports Server (NTRS)

    Karr, G. R.; Hendricks, J. B.

    1985-01-01

    The development of the Infrared Telescope for Spacelab 2 is discussed. The design, development, and testing required to interface a stationary superfluid helium dewar with a scanning cryostate capable of operating in the zero-g environment in the space shuttle bay is described.

  2. Littrow spectrographs for moderate resolution infrared applications

    NASA Astrophysics Data System (ADS)

    Warren, David W.; Lampen, Sara

    2016-09-01

    The Littrow form of spectrograph has a long and storied history in astronomical spectroscopy since its presentation in 1862 by Otto von Littrow. Light from an input slit traverses the same optical elements in reaching the dispersing element (prism or grating) and returning to a focused, dispersed image at the focal plane. This 1:1 symmetry helps cancel aberrations in the reimaging optics while presenting the dispersing element with the geometry most favorable to dispersion, efficiency and anamorphic scale change. Historically, Littrow spectrographs have not been pushed to high throughputs (fast f/ratios). However in the short- and mid-wave infrared particularly, high index, low dispersion materials like silicon and germanium can be combined effectively into compact, high throughput (sounders. We present some high throughput Littrow spectrograph concepts designed for infrared atmospheric sounding missions and incorporating both plane and immersion gratings.

  3. TIME-DEPENDENT INFRARED STUDIES.

    DTIC Science & Technology

    INFRARED RESEARCH, TIME , INFRARED PHENOMENA, INFRARED RADIATION, INFRARED SPECTROSCOPY, HIGH ALTITUDE, SOLAR ATMOSPHERE, TRANSMISSIONS(MECHANICAL), VIBRATION, QUANTUM THEORY, CALIBRATION, INFRARED SCANNING.

  4. Inter-Satellite Calibration Linkages for the Visible and Near-Infrared Channels of the Advanced Very High Resolution Radiometer on the NOAA-7, -9, and -11 Spacecraft. Revised

    NASA Technical Reports Server (NTRS)

    NagarajaRao, C. R.; Chen, J.

    1996-01-01

    The post-launch degradation of the visible (channel 1: 0.58- 068 microns) and near-infrared (channel 2: approx. 0.72 - l.l microns) channels of the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-7, -9, and -11 Polar-orbiting Operational Environmental Satellites (POES) was estimated using the south-eastern part of the Libyan Desert as a radiometrically stable calibration target. The relative annual degradation rates, in per cent, for the two channels are, respectively: 3.6 and 4.3 (NOAA-7); 5.9 and 3.5 (NOAA-9); and 1.2 and 2.0 (NOAA-11). Using the relative degradation rates thus determined, in conjunction with absolute calibrations based on congruent path aircraft/satellite radiance measurements over White Sands, New Mexico (USA), the variation in time of the absolute gain or slope of the AVHRR on NOAA-9 was evaluated. Inter-satellite calibration linkages were established, using the AVHRR on NOAA-9 as a normalization standard. Formulae for the calculation of calibrated radiances and albedos (AVHRR usage), based on these interlinkages, are given for the three AVHRRs.

  5. Infrared floodlight

    DOEpatents

    Levin, Robert E.; English, George J.

    1986-08-05

    An infrared floodlight assembly designed particularly for security purposes and including a heat-conducting housing, a lens secured to the housing to provide a closure therefor, and a floodlight located within (and surrounded by) the housing. The floodlight combines the use of a tungsten halogen light source and dichroic hot and cold mirrors for directing substantially only infrared radiation toward the assembly's forward lens. Visible radiation is absorbed by the housing's interior wall(s) and, optionally, by a filter located between the floodlight and lens. An optional means may be used within the floodlight to reflect all forward radiation back toward the paraboloidal hot mirror or, alternatively, to reflect only visible radiation in this direction. The dichroic hot and cold mirrors preferably each comprise a glass substrate having multiple layers of titanium dioxide and silicon dioxide thereon.

  6. The Radiative Impact of Water Ice Clouds from a Reanalysis of Mars Climate Sounder Data

    NASA Astrophysics Data System (ADS)

    Steele, L.; Lewis, S.; Patel, M.

    2014-12-01

    We use a data assimilation scheme coupled to a global climate model (GCM) to investigate the radiative impact of water ice clouds in the atmosphere of Mars. Temperature profiles from Mars Climate Sounder (MCS) are assimilated directly into the GCM. The water ice opacity profiles are used to build a four-dimensional time-space map of water ice clouds, which is then used by the GCM to produce the radiative forcing associated with clouds. This procedure allows clouds to be inserted into the model at the correct time and location, producing the most realistic state from which to analyse cloud radiative effects. The resulting data set allows a detailed study of the atmospheric state that is not possible using observations or models alone. The results show that tropical clouds have a greater impact on the local atmosphere than polar hood clouds, increasing diurnally-averaged temperatures at the 10 Pa level by around 10-15 K. The small radiative impact of the polar hood clouds may be caused by limitations of the MCS retrieval algorithm, meaning optically thick near-surface clouds are not retrieved. Tropical clouds also strengthen the meridional overturning circulation, leading to increased temperatures in the polar warmings by around 6-8 K, and increased temperatures in the tropics by around 2 K due to increased dust loading. The positions and wind speeds of the tropical and high-latitude jets are also modified through changes to the meridional temperature gradients. Work is ongoing to couple the assimilation of ice opacities to a model including an active water cycle.

  7. Phase Change Material for Temperature Control of Imager or Sounder on GOES Type Satellites in GEO

    NASA Technical Reports Server (NTRS)

    Choi, Michael

    2013-01-01

    An imager or sounder on satellites, such as the Geostationary Operational Environmental Satellite (GOES), in geostationary orbit (GEO) has a scan mirror and motor in the scan cavity. The GEO orbit is 24 hours long. During part of the orbit, direct sunlight enters the scan aperture and adds heat to components in the scan cavity. Solar heating also increases the scan motor temperature. Overheating of the scan motor could reduce its reliability. For GOES-N to P, a radiator with a thermal louver rejects the solar heat absorbed to keep the scan cavity cool. A sunshield shields the radiator/louver from the Sun. This innovation uses phase change material (PCM) in the scan cavity to maintain the temperature stability of the scan mirror and motor. When sunlight enters the scan aperture, solar heating causes the PCM to melt. When sunlight stops entering the scan aperture, the PCM releases the thermal energy stored to keep the components in the scan cavity warm. It reduces the heater power required to make up the heat lost by radiation to space through the aperture. This is a major advantage when compared to a radiator/ louver. PCM is compact because it has a high solid-to-liquid enthalpy. Also, it could be spread out in the scan cavity. This is another advantage. Paraffin wax is a good PCM candidate, with high solid-to-liquid enthalpy, which is about 225 kJ/kg. For GOES-N to P, a radiator with a louver rejects the solar heat that enters the aperture to keep the scan cavity cool. For the remainder of the orbit, sunlight does not enter the scan aperture. However, the radiator/louver continues radiating heat to space because the louver effective emittance is about 0.12, even if the louver is fully closed. This requires makeup heater power to maintain the temperature within the stability range.

  8. Definition and preliminary design of the Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 2

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The steps and engineering trades and analyses used in establishing the initial requirements and in developing a concept and configuration for the laser atmospheric wind sounder (LAWS) instrument. A summary of the performance anticipated from the baseline configuration, and a bibliography are presented. LAWS, which is a facility instrument of the Earth observing system (EOS), is the culmination of over 20 years of effort in the field of laser Doppler wind sensing and will be the first instrument to fly in space capable of providing global-scale tropospheric wind profiles at high spatial resolutions. Global-scale wind profiles are necessary for: (1) more accurate diagnosis of large-scale circulation and climate dynamics; (2) improved numerical weather prediction; (3) improved understanding of mesoscale systems; and (4) improved understanding of global biogeochemical and hydrologic cycles. The objective of phase 1 was to define and perform a preliminary design for the LAWS instrument. The definition phase consisted of identifying realistic concepts for LAWS and analyzing them in sufficient detail to be able to choose the most promising one for the LAWS instrument. Systems and subsystems configurations were then developed for the chosen concept. The concept and subsequent configuration were to be compatible with two prospective platforms: the Japanese polar orbiting platform (JPOP) and as an attached payload on the Space Station Freedom. After a thorough and objective concept selection process, a heterodyne detection Doppler lidar using a CO2 laser transmitter operating a 9.1 micron over a 2.1 micron solid state system was chosen. A configuration for LAWS that meets the performance requirements was designed at the conclusion of phase 1.

  9. Thermal Stability of a 4 Meter Primary Reflector for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Cofield, Richard; Kasl, Eldon P.

    2010-01-01

    We describe the fabrication and thermal-stability analysis and test of a composite de