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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.
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This paper provides an overview of the Tropospheric Emission Spectrometer (TES) and its mission, as a part of NASA's Earth Observing System (EOS).
Two independent tunable diode laser spectrometers are resident aboard the Mars Polar Lander as part of the Mars Volatile and Climate Surveyor payload.
We validate 1997 Airborne Visible-Infrared Imaging Spectrometer (AVIRIS) reflectance spectra covering 0.4 meu - 2.4 meu from a stable, flat mineralogically characterized man-made target at Ray Mine, AZ, the site for an EPA/NASA assessment of the utility of remote sensing for monitoring acid drainage from an active open pit mine.
Several designs that are based on the Offner concentric spectrometer form, with the grating formed on the convex secondary mirror.
Mass and power for the next generation of NASA's heterodyne spectrometers must be greatly reduced to satisfy the constraints of future small-spacecraft missions. Here we present a new receiver concept for remote sensing in the Solar System, with greatly reduced mass, power, and size compared to instruments implemented in current missions.
Mass and power for the next generation of NASA's heterodyne spectrometers must be greatly resuced to satisfy the constraints of future small-spacecraft missions.
Earth-looking imaging spectrometers operating in the solar reflected spectrum, measure spectra of the total upwelling radiance for each spatial element in an image. These measurements are used to derive physical parameters of the Earth's surface and atmosphere based on the energy, molecular absorption, and constituent scattering characteristics expressed in the spectra over the region of the image.
Liquid crystal tunable filters are useful in building compact multi-spectral instruments. The system is portable and adaptable for use in a variety of fields of study in the visible and near-infrared regions of the spectrum.We will present data from calibration targets and some applications, results of the spectral calibration of a spectrometer system, and results of environmental (vibration, radiation, shock, and thermal) testing. Data acquisition and system design are also discussed.
A minature quadrupole mass-spectrometer array consisting of 16 rods in a 4X4 array is reported.
The mass and power of a heterodyne spectrometer must be greatly reduced to satisfy small space mission constraints. We report on a 220 GHz receiver, requiring less than 4.8 W, with a mass of 1.25 kg. The mass and power savings are achieved through reducing components to a minimum, while providing performance for a Martian atmospheric sounder.
High resolution studies of the isotopic composition of heavy elements in the galactic cosmic radiation have been performed using satellites. The performance of the Tracking Heavy Isotope Spectrometer Telescopes for Low Energies (THISTLE) is investigated using data from a balloon flight carried out in 1993. The instrument design is discussed; and data, and additional analysis, is shown.
A laboratory calibration of the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) allowed experimentation with several innovative calibration techniques that would improve calibration accuracy, provide independent checks for systematic errors, and reduce the time required to collect a calibration data set.
The conceptual design for miniaturization of two versatile types of mass spectrometers will be discussed: the quadrupole and the ion trap.
The Airborne Visible/Infrared Imaging Spectrometer measures spatial images of the total upwelling spectral radiance from 400 to 2500 nm through 10 nm spectral channels. Quantitative research and application objectives for surface investigations require conversion of the measured radiance to surface reflectance or surface leaving radiance. To calculate apparent surface reflectance an estimation of atmospheric water vapor abundance, cirrus cloud effects, surface pressure elevation and aerosol optical depth is also required. Algorithms for the estimation of these parameters from the AVIRIS data themselves are described. Based upon these determined atmospheric parameters we show an example of the calculation of apparent surface reflectance from the AVIRIS-measured radiance using a radiative transfer code.
The properties of convex gratings fabricated by electron-beam lithography are investigated. Three grating types are shown. These gratings allow the optical designer to fully realize the considerable advantages of concentric spectrometer forms.
Designing an imaging spectrometer using and AOTF can be a difficult task since there is no software that can simulate the bulk diffraction that takes place in the AOTF material.
We describe a pushbroom imaging spectrometer having a number of attractive features for remote sensing applications, including compact and simple form, good image quality, high effciency, and very low levels of distortion.
Several improvements have been made to the Airborne Visible/Infrared Imaging Spectrometer (AVRIS) since 1994--new focal plane arrays, a new analog and digital chain and an onboard calibration lamp controlled by radiance feedback. These changes increased the signal-to- noise ratio by 2 to 3 times, eliminated noise spikes and the need for spectral sampling, and greatly reduced dark-current noise.