Showing papers on "VNIR published in 1993"

Compact airborne spectrographic imager (CASI): a progress review

Abstract: The compact airborne spectrographic imager (casi) is a pushbroom imaging spectrograph intended for acquisition of VNIR multispectral imagery from light aircraft. An ongoing development program has resulted in improvements to the radiometric calibration procedures, and the capability for roll correction and geocorrection of imagery acquired with casi. A variety of monitoring and research missions have been undertaken for aquatic and terrestrial applications and development of remote sensing methodologies.

Radiometric Calibration of the EOS ASTER Instrument

Abstract: Pre-flight and in-flight radiometric calibration plans are described for a multispectral optical imager of high spatial resolution for remote sensing of land surfaces and clouds from orbit, which will be launched in 1998 on NASA's EOS-AM1 spacecraft. The instrument named ASTER consists of three radiometers for three separate spectral regions, the visible and near-infrared radiometer (VNIR), the shortwave infrared radiometer (SWIR), and the thermal infrared radiometer (TIR). Absolute radiometric accuracy to better than 4% is required for the VNIR and SWIR radiance measurements, and from 1 K to 3 K, depending on the temperature region, from 200 K to 370 K for the TIR temperature measurements. The basic approach to in-flight calibration is to introduce a reference beam at the front end of the radiometer to calibrate the whole system in orbit. Thus the ASTER instrument is installed with internal on-board calibration units which include, as reference sources, incandescent lamps for the VNIR and SWIR and a black-body radiator for the TIR. Calibration reliability of the VNIR and SWIR is enhanced by a dual system of on-board calibration units and high stability halogen lamps. A ground calibration system of spectral radiances traceable to fixed-point black bodies is used for the pre-flight VNIR and SWIR calibrations.

Design challenges of ASTER in shortwave infrared spectral region

Abstract: The advanced spaceborne thermal emission and reflection radiometer (ASTER) to be mounted on the U.S.'s EOS-AM1 polar orbiting platform, scheduled for launch in 1998 by NASA, will be part of a remote sensing equipment complex whose purpose is to locate mineral resources and monitor the earth's environment. The ASTER, a Japanese mission, consists of three optical sensors -- the visible and near-infrared radiometer (VNIR), the short wavelength infrared radiometer (SWIR), and the thermal infrared radiometer (TIR), which has 5 spectral bands in the thermal infrared region (8 - 12 micrometers ). The TIR, which is the focus of this paper, is expected to provide high temperature and ground resolution in its acquisition of surface temperature information from the ground, oceans, and clouds. Such information will be useful in monitoring volcano activity, desertification, forestation and flora distribution, and the global climate as a whole. The TIR will also acquire information on the thermal radiation spectrum that will be useful in classifying rock formations and composition.

ASTER instrument calibration plan

Abstract: ASTER is composed of three radiometers for separate wavelength regions: visible and near infrared radiometer (VNIR) and short wavelength infrared radiometer (SWIR) both in the solar reflection region, and thermal infrared radiometer (TIR) in the thermal emission region. Each radiometer will be calibrated before launch on the ground, and after launch in orbit. This paper describes the calibration plan of ASTER radiometer.

Design challenges of ASTER in visible and near-infrared spectral region

Abstract: This paper presents the preliminary design results of the visible and near-infrared radiometer (VNIR) of the ASTER instrument for the EOS-AM1 program. The VNIR is a spaceborne radiometer employing push broom scanning with 5,000 element CCD sensors. The VNIR provides image data with high spatial resolution of 15 X 15 m, and has the pointing capability of +/- 24 deg in the cross-track direction to obtain a wide swath. The VNIR also provides stereoscopic image data in band 3 (0.76 - 0.86 micrometers ) with nadir- and backward- looking telescopes for topographical studies and mapping of the earth.

Digital terrain model of JERS-1 data for ASTER VNIR stereo application

Abstract: Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) has an along track stereo capability for the generation of a digital terrain model with 0.6 base to height ratio (B/H). JERS-1 data has a similar stereo mapping capability, and its stereo data was used to estimate the accuracy of the extracted terrain data with the outer orientation method and satellite orbit parameter method. The relative error for the height was 57 m, and it was found that a 1:200000 scale map could be possible with ASTER data which has a spatial resolution 15 m. >

Lunar Scout Infrared Detector (LSIRD): simple low-cost imaging spectrometer

Abstract: A novel design for a compact, light weight, imaging spectrometer has been proposed for an orbiting Lunar mapping mission. Simple in design, its dual arm optical system employs a transmission grating and a dichroic mirror to provide continuous two-octave spectral response. The grating's first order wavelengths are reflected into the SWIR arm, while the second order wavelengths are transmitted to the VNIR arm. The instrument design is that of a push broom camera. It uses one of the detector(s) dimensions for spectral selection, the other detector(s) dimension for cross-track spatial selection, and the forward motion of the platform (in this case, a spacecraft) for down-track spatial coverage.

An imaging spectrometer for planetary studies

Abstract: VNIR, a Visible Near-Infrared Mapping Spectrometer, was developed at IFSI-CNR and it is the visible channel of an experiment, named OMEGA, to be flown on the Russian Mars 94 mission, that will provide detailed mineralogical and chemical maps of the Mars surface. We have tested and calibrated the instrument in our laboratory, using it to take images and spectra of meteorites and terrestrial rocks. In the present work a description of the camera with some preliminary results of this activity are given.

The results of performance test of JERS-1 OPS data

Abstract: Japanese Earth Resources Satellite-1 (JERS-1) was launched in Feb. 1992. It carries two sensors: Optical Sensor (OPS) and Synthetic Aperture Radar (SAR) and is now gathering data. The performance of the OPS data is investigated in the study. A performance test is carried out using the following items: image quality, spatial resolution, band registration accuracy, geographic position accuracy of tick marks information, noise level and computation accuracy of 3 dimensional coordinates by OPS stereo data. The images of the VNIR hands are generally good, but images of the SWIR bands are not so clear compared with VNIR. The results of the performance test of the other items are also described. >