SEARCH · Search NASA

Results for “Mid-wave infrared”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

All sources NASA NTRS DOE OSTI

NASA NTRS2000

Observations of Leonid Meteors Using a Mid-Wave Infrared Imaging Spectrograph

We report broadband 3-5.5 micrometer detections of two Leonid meteors observed during the 1998 Leonid Multi-Instrument Aircraft Campaign. Each meteor was detected at only one position along their trajectory just prior to the point of maximum light emission. We describe the particular aspects of the Aerospace Corp. Mid-wave Infra-Red Imaging Spectrograph (MIRIS) developed for the observation of short duration transient events that impact its ability to detect Leonid meteors. This instrument had its first deployment during the 1998 Leonid MAC. We infer from our observations that the mid-infrared light curves of two Leonid meteors differed from the visible light curve. At the points of detection, the infrared emission in the MIRIS passband was 25 +/- 4 times that at optical wavelengths for both meteors. In addition, we find an upper limit of 800 K for the solid body temperature of the brighter meteor we observed, at the point in the trajectory where we made our mid-wave infrared detection.

Rossano, G. S.↗

NASA NTRS2008

Comparison of Terra and Aqua MODIS VIS Bands On-Orbit Response

The Moderate Resolution Imaging Spectroradiometer (MODIS) has 36 spectral bands with a total of 490 detectors, covering spectral regions in the visible (VIS), near-infrared (NIR), short-wave infrared (SWIR), mid-wave infrared (MWIR), and long-wave infrared (LWIR). MODIS is a cross-track scanning radiometer which collects data using a rotating scan mirror (both sides) over a wide range of scan angles. The VIS, NIR, and SWIR bands (bands 1-19 and 26) make measurements of daytime surface reflected radiances, thus are referred to as the reflective solar bands (RSB). MODIS was built with a complete set of on-board calibrators, capable of providing radiometric, spatial, and spectral calibration and characterization during its entire mission. The RSB on-orbit calibration is primarily provided using a solar diffuser (SD) and a solar diffuser stability monitor (SDSM). The SD and SDSM calibration system is operated on a regular (weekly to bi-weekly) basis. The spectro-radiometric calibration assembly (SRCA) is another on-hoard calibrator that also provides RSB radiometric calibration support. For this purpose, the SRCA is operated in a radiometric mode on a monthly basis. A complete SRCA radiometric calibration is performed using different lamp configurations, or different radiance levels, to cover the range of RSB gain. Two additional SRCA modes with slightly different configurations are designed and operated for sensor on-orbit spectral and spatial characterization. In addition to its on-hoard calibrators, each MODIS makes monthly lunar observations to monitor RSB radiometric calibration stability. The MODIS lunar observations are made through its space view (SV) port at nearly the same lunar phase angles via spacecraft roll maneuvers. The SD, SRCA, and lunar measurements are made at different scan angles and data samples are collected for all spectral bands and detectors using both sides of the scan minor. Since launch, Terra and Aqua MODIS have operated successfully for more than 8 years and 6 years, respectively. Many SD/SDSM, SRCA, and lunar observations have been made by each instrument and used to derive RSB on-orbit calibration parameters, enabling corrections for sensor response changes and changes of the response versus scan angle (RVS). In general, the RSB calibration parameters are updated regularly into the MODIS Level 1B (LIB) code in support of continuous data processing for all MODIS science data products. This paper provides a brief description of MODIS RSB calibration methodologies and approaches, and summarizes on-orbit changes of their responses (gains), particularly for the VIS spectral bands.

Xiong, Xiaoxiong↗

NASA NTRS2008

Characterization of MODIS VIS/NIR Spectral Band Detector-to-Detector Difference

MODIS has 36 spectral bands with wavelengths in the visible (VIS), near-infrared (NIR), shortwave infrared (SWTR), mid-wave infrared (MWIR), and long-wave infrared (LWIR). It makes observations at three nadir spatial resolutions: 0,25km for bands 1-2 with 40 detectors per band, 0.5km for bands 3-7 with 20 detectors per band, and 1km for bands 8-36 with 10 detectors per band. The VIS, NIR, and S\VIR spectral bands are the reflective solar bands (RSB), which are calibrated on-orbit by a solar diffuser (SD). In addition, MODIS lunar observations are used to track the RSB calibration stability. In this study, we examine detector-to-detector calibration difference for the VIStNIR spectral bands using the SD and lunar observations. The results will be compared with an independent analysis with additional information, such as polarization correction, derived from standard ocean color data products. The current MODIS RSB calibration approach only carries a band-averaged RVS (response versus scan angle) correction. The results from this study suggest that a detector-based RVS correction should be used to improve the L1B data quality, especially for several VIS bands in Terra MODIS due to large changes of the scan mirror's optical properties in recent years.

Xiong, X.↗

NASA NTRS2009

An Overview of MODIS Calibration and Characterization and Lessons Learned

The Moderate Resolution Imaging Spectroradiometer (MODIS) is a key instrument for NASA's EOS missions. Two nearly identical copies have flown on the Terra and Aqua spacecraft for more than 9 years and 6 years since their launch in December 1999 and May 2002, respectively. MODIS observations and associated data products have been widely used by the science community and users worldwide for studies of Earth's system of land, oceans, and atmosphere. MODIS was developed based on the desire of the science community to extend and enhance heritage sensors' data records. It was designed with enhancements made over its heritage sensors in terms of its spectral, spatial, and radiometric characteristics. It is a cross-track scanning radiometer, that uses a two-sided scan mirror, collecting data in 36 spectral bands covering spectral regions of visible (VIS), near-infrared (NIR), short-wave infrared (SWIR), mid-wave infrared (MWIR), and long-wave infrared (LWIR). The VIS, NIR, and SWIR bands (bands 1-19 and 26), which make measurements of daytime surface reflected radiances, are referred to as the reflective solar bands (RSB). The MWIR and LWIR bands (20-25 and 27-36), which measure both the daytime and nighttime scene emissive radiances, are thus referred to as the thermal emissive bands (TEB). In this paper, we provide an overview of MODIS instrument calibration and characterization methodologies, activities, and results from pre-launch to post launch, with emphasis on the lessons learned from its design to on-orbit operation. Currently, both instruments are operated normally and all the on-orbit calibration activities are performed on a regular basis with some at slightly reduced frequencies. The TEB responses have been extremely stable with less than 0.3% change per year. For the RSB, the changes are wavelength and scan angle dependent with the largest changes in the VIS spectral bands. As both Terra and Aqua MODIS continue to operate beyond their prime missions, constant effort is still needed to maintain instrument and calibration and data product quality. This paper shows that the lessons from Terra MODIS design, test, and operation, have greatly benefitted Aqua MODIS. Because of this, Aqua MODIS overall performance is better than Terra MODIS. It is not surprising that lessons from MODIS calibration and characterization, from methodologies to on-orbit implementation, have also provided valuable information for the design and development of future earth observing missions/sensors, such as VHRS on the NPP and NPOESS, ABI on GOES-R, OLI on LDCM, and the reflective solar sensor on CLARREO.

Xiong, Xiaxiong↗

NASA NTRS2011

Unmanned Ground Vehicle Perception Using Thermal Infrared Cameras

The ability to perform off-road autonomous navigation at any time of day or night is a requirement for some unmanned ground vehicle (UGV) programs. Because there are times when it is desirable for military UGVs to operate without emitting strong, detectable electromagnetic signals, a passive only terrain perception mode of operation is also often a requirement. Thermal infrared (TIR) cameras can be used to provide day and night passive terrain perception. TIR cameras have a detector sensitive to either mid-wave infrared (MWIR) radiation (3-5?m) or long-wave infrared (LWIR) radiation (8-12?m). With the recent emergence of high-quality uncooled LWIR cameras, TIR cameras have become viable passive perception options for some UGV programs. The Jet Propulsion Laboratory (JPL) has used a stereo pair of TIR cameras under several UGV programs to perform stereo ranging, terrain mapping, tree-trunk detection, pedestrian detection, negative obstacle detection, and water detection based on object reflections. In addition, we have evaluated stereo range data at a variety of UGV speeds, evaluated dual-band TIR classification of soil, vegetation, and rock terrain types, analyzed 24 hour water and 12 hour mud TIR imagery, and analyzed TIR imagery for hazard detection through smoke. Since TIR cameras do not currently provide the resolution available from megapixel color cameras, a UGV's daytime safe speed is often reduced when using TIR instead of color cameras. In this paper, we summarize the UGV terrain perception work JPL has performed with TIR cameras over the last decade and describe a calibration target developed by General Dynamics Robotic Systems (GDRS) for TIR cameras and other sensors.

terrain classification↗

NASA NTRS2013

Suomi NPP VIIRS Prelaunch and On-orbit Geometric Calibration and Characterization

The Visible Infrared Imager Radiometer Suite (VIIRS) sensor was launched 28 October 2011 on the Suomi National Polarorbiting Partnership (SNPP) satellite. VIIRS has 22 spectral bands covering the spectrum between 0.412 m and 12.01 m, including 16 moderate resolution bands (M-bands) with a spatial resolution of 750 m at nadir, 5 imaging resolution bands (I-bands) with a spatial resolution of 375 m at nadir, and 1 day-night band (DNB) with a near-constant 750 m spatial resolution throughout the scan. These bands are located in a visible and near infrared (VisNIR) focal plane assembly (FPA), a short- and mid-wave infrared (SWMWIR) FPA and a long-wave infrared (LWIR) FPA. All bands, except the DNB, are co-registered for proper environmental data records (EDRs) retrievals. Observations from VIIRS instrument provide long-term measurements of biogeophysical variables for climate research and polar satellite data stream for the operational communitys use in weather forecasting and disaster relief and other applications. Well Earth-located (geolocated) instrument data is important to retrieving accurate biogeophysical variables. This paper describes prelaunch pointing and alignment measurements, and the two sets of on-orbit correction of geolocation errors, the first of which corrected error from 1,300 m to within 75 m (20 I-band pixel size), and the second of which fine tuned scan angle dependent errors, bringing VIIRS geolocation products to high maturity in one and a half years of the SNPP VIIRS on-orbit operations. Prelaunch calibration and the on-orbit characterization of sensor spatial impulse responses and band-to-band co-registration (BBR) are also described.

Geolocation↗

NASA NTRS2003

Detecting water hazards for autonomous off-road navigation

Detecting water hazards for autonomous, off-road navigation of unmanned ground vehicles is a largely unexplored problem. In this paper, we catalog environmental variables that affect the difficulty of this problem, including day vs. night operation, whether the water reflects sky or other terrain features, the size of the water body, and other factors. We briefly survey sensors that are applicable to detecting water hazards in each of these conditions. We then present analyses and results for water detection for four specific sensor cases: 1) using color image classification to recognize sky reflections in water during the day, 2) using ladar to detect the presence of water bodies and to measure their depth, 3) using short-wave infrared (SWIR) imagery to detect water bodies, as well as snow and ice, and 4) using mid-wave infrared (MWIR) imagery to recognize water bodies at night. For color imagery, we demonstrate solid results with a classifier that runs at nearly video rate on a 433 MHz processor. For ladar, we present a detailed propagation analysis that shows the limits of water body detection and depth estimation as a function of look ahead distance, water depth, and ladar wavelength. For SWIR and MWIR, we present sample imagery from a variety of data collections that illustrate the potential of these sensors. These results demonstrate significant progress on this problem.

McHenry, Mike↗

NASA NTRS1996

Balancing Science Objectives and Operational Constraints: A Mission Planner's Challenge

The Air Force minute sensor technology integration (MSTI-3) satellite's primary mission is to characterize Earth's atmospheric background clutter. MSTI-3 will use three cameras for data collection, a mid-wave infrared imager, a short wave infrared imager, and a visible imaging spectrometer. Mission science objectives call for the collection of over 2 million images within the one year mission life. In addition, operational constraints limit camera usage to four operations of twenty minutes per day, with no more than 10,000 data and calibrating images collected per day. To balance the operational constraints and science objectives, the mission planning team has designed a planning process to e event schedules and sensor operation timelines. Each set of constraints, including spacecraft performance capabilities, the camera filters, the geographical regions, and the spacecraft-Sun-Earth geometries of interest, and remote tracking station deconflictions has been accounted for in this methodology. To aid in this process, the mission planning team is building a series of tools from commercial off-the-shelf software. These include the mission manifest which builds a daily schedule of events, and the MSTI Scene Simulator which helps build geometrically correct scans. These tools provide an efficient, responsive, and highly flexible architecture that maximizes data collection while minimizing mission planning time.

Weldy, Michelle↗

NASA NTRS1996

Vibration Isolation, Suppression, Steering, and Pointing (VISSP)

The design of a six degree of freedom flight vibration isolation suppression and steering (VISS) subsystem for a mid-wave infrared camera on the top of a spacecraft is presented. The development of a long stroke piezoelectric, redundant, compact, low stiffness and power efficient actuator is summarized. A subsystem that could be built and validated for flight within 15 months was investigated. The goals of the VISS are 20 dB vibration isolation above 2 Hz, 15 dB vibration suppression of disturbances at about 60 Hz and 120 Hz, and +/- 0.3 deg steering at 2 Hz and 4 Hz.

Wada, Ben K.↗

NASA NTRS2007

Multiyear On-orbit Calibration and Performance of Terra MODIS Thermal Emissive Bands

Since launch in December 1999, Terra MODIS has been making continuous Earth observations for more than seven years. It has produced a broad range of land, ocean, and atmospheric science data products for improvements in studies of global climate and environmental change. Among its 36 spectral bands, there are 20 reflective solar bands (RSB) and 16 thermal emissive bands (TEB). MODIS thermal emissive bands cover the mid-wave infrared (MWIR) and long-wave infrared (LWIR) spectral regions with wavelengths from 3.7 to 14.4pm. They are calibrated on-orbit using an on-board blackbody (BB) with its temperature measured by a set of thermistors on a scan-by-scan basis. This paper will provide a brief overview of MODIS TEB calibration and characterization methodologies and illustrate on-board BB functions and TEB performance over more than seven years of on-orbit operation and calibration. Discussions will be focused on TEB detector short-term stability and noise characterization, and changes in long-term response (or system gain). Results show that Terra MODIS BB operation has been extremely stable since launch. When operated at its nominal controlled temperature of 290K, the BB temperature variation is typically less than +0.30mK on a scan-by-scan basis and there has been no time-dependent temperature drift. In addition to excellent short-term stability, most TEB detectors continue to meet or exceed their specified noise characterization requirements, thus enabling calibration accuracy and science data product quality to be maintained. Excluding the noisy detectors identified pre-launch and those that occurred post-launch, the changes in TEB responses have been less than 0.7% on an annual basis. The optical leak corrections applied to bands 32-36 have been effective and stable over the entire mission

Xiong, Xiaoxiong↗

NASA NTRS2012

Recent Progress in Entry Radiation Measurements in the NASA Ames Electric ARC Shock Tube Facility

The Electric Arc Shock Tube (EAST) at NASA Ames Research Center is NASA's only working shock tube capable of obtaining conditions representative of entry in a multitude of planetary atmospheres. The facility is capable of mapping spectroscopic signatures of a wide range of planetary entries from the Vacuum Ultraviolet through Mid-Wave Infrared (120-5500 nm). This paper summarizes the tests performed in EAST for Earth, Mars and Venus entries since 2008, then focuses on a specific test case for CO2/N2 mixtures. In particular, the paper will focus on providing information for the proper interpretation of the EAST data.

Cruden, Brett A.↗

NASA NTRS2009

Large Format Multicolor QWIP Focal Plane Arrays

Mid-wave infrared (MWIR) and long-wave infrared (LWIR) multicolor focal plane array (FPA) cameras are essential for many DoD and NASA applications including Earth and planetary remote sensing. In this paper we summarize our recent development of large format multicolor QWIP FPA that cover MWIR and LWIR bands.

infrared detectors↗

NASA NTRS2015

Radiative Heating on the After-Body of Martian Entry Vehicles

This paper presents simulations of the radiative heat flux imparted on the after-body of vehicles entering the Martian atmosphere. The radiation is dominated by CO2 bands emitting in the mid-wave infrared spectral region. This mechanism has traditionally not been considered in the design of past Mars entry vehicles. However, with recent analysis showing that the CO2 radiation can be greater than convective heating in the wake, and with several upcoming and proposed missions to Mars potentially affected, an investigation of the impact of this radiation is warranted. The focus of this paper is to provide a better understanding of the impact to aerothermal heating predictions and to provide comparisons between NASA's two main radiation codes, NEQAIR and HARA. The tangent slab approximation is shown to be overly conservative, by as much as 58 percent, for most back- shell body point locations compared to using a full angular integration method. However, due to the complexity of the wake flow, it is also shown that tangent slab does not always represent an upper limit for radiative heating. Furthermore, analysis in this paper shows that it is not possible to provide a general knock-down factor from the tangent slab results to those obtained using the more rigorous full integration method. When the radiative heating is accounted for on the after-body, the unmargined total heat flux can be as high as 14 watts per square centimeter.

After-body↗

NASA NTRSDate not supplied

Updates to the NEQAIR Radiation Solver

The NEQAIR code is one of the original heritage solvers for radiative heating prediction in aerothermal environments, and is still used today for mission design purposes. This paper discusses the implementation of the first major revision to the NEQAIR code in the last five years, NEQAIR v14.0. The most notable features of NEQAIR v14.0 are the parallelization of the radiation computation, reducing runtimes by about 30×, and the inclusion of mid-wave CO2 infrared radiation.

Radiation↗

NASA NTRS2001

Infrared Sensing Aeroheating Flight Experiement: STS-96 Flight Results

Major elements of an experiment called the Infrared Sensing Aeroheating Flight Experiment are discussed. The primary experiment goal is to provide reentry global temperature images from infrared measurements to define the characteristics of hypersonic boundary-layer transition during flight. Specifically, the experiment is to identify, monitor, and quantify hypersonic boundary layer windward surface transition of the X-33 vehicle during flight. In addition, the flight data will serve as a calibration and validation of current boundary layer transition prediction techniques, provide benchmark laminar, transitional, and fully turbulent global aeroheating data in order to validate existing wind tunnel and computational results, and to advance aeroheating technology. Shuttle Orbiter data from STS-96 used to validate the data acquisition and data reduction to global temperatures, in order to mitigate the experiment risks prior to the maiden flight of the X-33, is discussed. STS-96 reentry mid-wave (3-5 Pm) infrared data were collected at the Ballistic Missile Defense Organization/Innovative Sciences and Technology Experimentation Facility site at NASA-Kennedy Space Center and subsequently mapped into global temperature contours using ground calibrations only. A series of image mapping techniques have been developed in order to compare each frame of infrared data with thermocouple data collected during the flight. Comparisons of the ground calibrated global temperature images with the corresponding thermocouple data are discussed. The differences are shown to be generally less than about 5%, which is comparable to the expected accuracy of both types of aeroheating measurements.

Blanchard, Robert C.↗

NASA NTRS2015

Principle Component Analysis of AIRS and CrIS Data

Synthetic Eigen Vectors (EV) used for the statistical analysis of the PC reconstruction residual of large ensembles of data are a novel tool for the analysis of data from hyperspectral infrared sounders like the Atmospheric Infrared Sounder (AIRS) on the EOS Aqua and the Cross-track Infrared Sounder (CrIS) on the SUOMI polar orbiting satellites. Unlike empirical EV, which are derived from the observed spectra, the synthetic EV are derived from a large ensemble of spectra which are calculated assuming that, given a state of the atmosphere, the spectra created by the instrument can be accurately calculated. The synthetic EV are then used to reconstruct the observed spectra. The analysis of the differences between the observed spectra and the reconstructed spectra for Simultaneous Nadir Overpasses of tropical oceans reveals unexpected differences at the more than 200 mK level under relatively clear conditions, particularly in the mid-wave water vapor channels of CrIS. The repeatability of these differences using independently trained SEV and results from different years appears to rule out inconsistencies in the radiative transfer algorithm or the data simulation. The reasons for these discrepancies are under evaluation.

infrared↗

NASA NTRS1993

Evolution of miniature detectors and focal plane arrays for infrared sensors

Sensors that are sensitive in the infrared spectral region have been under continuous development since the WW2 era. A quest for the military advantage of 'seeing in the dark' has pushed thermal imaging technology toward high spatial and temporal resolution for night vision equipment, fire control, search track, and seeker 'homing' guidance sensing devices. Similarly, scientific applications have pushed spectral resolution for chemical analysis, remote sensing of earth resources, and astronomical exploration applications. As a result of these developments, focal plane arrays (FPA) are now available with sufficient sensitivity for both high spatial and narrow bandwidth spectral resolution imaging over large fields of view. Such devices combined with emerging opto-electronic developments in integrated FPA data processing techniques can yield miniature sensors capable of imaging reflected sunlight in the near IR and emitted thermal energy in the Mid-wave (MWIR) and longwave (LWIR) IR spectral regions. Robotic space sensors equipped with advanced versions of these FPA's will provide high resolution 'pictures' of their surroundings, perform remote analysis of solid, liquid, and gas matter, or selectively look for 'signatures' of specific objects. Evolutionary trends and projections of future low power micro detector FPA developments for day/night operation or use in adverse viewing conditions are presented in the following test.

Watts, Louis A.↗

NASA NTRS2014

Minority Carrier Lifetime Studies of Narrow Bandgap Antimonide Superlattices

In this study optical modulation response and photoluminescence spectroscopy were used to study mid-wave Ga-free InAs/InAsSb superlattices. The minority carrier lifetimes in the different samples varied from 480 ns to 4700 ns, partly due to different background doping concentrations. It was shown that the photoluminescence intensity can be used as a fast non-destructive tool to predict the material quality. It was also demonstrated that it is crucial to use a low excitation power in the photoluminescence measurements in order to get a good correlation between the photoluminescence intensity and the minority carrier lifetime.

minority carrier lifetime↗