Showing papers on "VNIR published in 1998"
TL;DR: ASTER will, for the first time, provide high-spatial resolution multispectral thermal infrared data from orbit and the highest spatial resolution surface spectral reflectance temperature and emissivity data of all of the EOS-AM1 instruments.
Abstract: The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a research facility instrument provided by the Ministry of International Trade and Industry (MITI), Tokyo, Japan to be launched on NASA's Earth Observing System morning (EOS-AM1) platform in 1998. ASTER has three spectral hands in the visible near-infrared (VNIR), six bands in the shortwave infrared (SWIR), and five bands in the thermal infrared (TIR) regions, with 15-, 30-, and 90-m ground resolution, respectively. The VNIR subsystem has one backward-viewing band for stereoscopic observation in the along-track direction. Because the data will have wide spectral coverage and relatively high spatial resolution, it will be possible to discriminate a variety of surface materials and reduce problems in some lower resolution data resulting from mixed pixels. ASTER will, for the first time, provide high-spatial resolution multispectral thermal infrared data from orbit and the highest spatial resolution surface spectral reflectance temperature and emissivity data of all of the EOS-AM1 instruments. The primary science objective of the ASTER mission is to improve understanding of the local- and regional-scale processes occurring on or near the Earth's surface and lower atmosphere, including surface-atmosphere interactions. Specific areas of the science investigation include the following: (1) land surface climatology; (2) vegetation and ecosystem dynamics; (3) volcano monitoring; (4) hazard monitoring; (5) aerosols and clouds; (6) carbon cycling in the marine ecosystem; (7) hydrology; (8) geology and soil; and (9) land surface and land cover change. There are three categories of ASTER data: a global map, regional monitoring data sets, and local data sets to be obtained for requests from individual investigators.
885 citations
TL;DR: The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is an advanced multispectral imager with high spatial, spectral, and radiometric resolution, built to fly on the EOS-AM1 spacecraft along with four other instruments, which will be launched in 1998.
Abstract: The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is an advanced multispectral imager with high spatial, spectral, and radiometric resolution, built to fly on the EOS-AM1 spacecraft along with four other instruments, which will be launched in 1998. The ASTER instrument covers a wide spectral region, from visible to thermal infrared with 14 spectral bands. To meet the wide spectral coverage, optical sensing units of ASTER are separated into three subsystems: visible and near-infrared (VNIR) subsystem, shortwave infrared (SWIR) subsystem, and thermal infrared (TIR) subsystem. ASTER also has an along-track stereoscopic viewing capability using one of the near-infrared bands. To acquire the stereo data, the VNIR subsystem has two telescopes, one for nadir and another for backward viewing. Several new technologies are adopted as design challenges to realize high performance. Excellent observational performances are obtained by a pushbroom VNIR radiometer with a high spatial resolution of 15 m, a pushbroom SWIR radiometer with high spectral resolution, and a whiskbroom-type TIR radiometer with high spatial, spectral, and radiometric resolutions. The preflight performance is evaluated through a protoflight model (PFM).
107 citations
TL;DR: The algorithm developed for the ASTER Level-1 data processing is described and the instrument configuration with multitelescopes requires highly refined ground processing for the generation of Level- 1 data products that are radiometrically calibrated and geometricrically corrected.
Abstract: The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is an advanced multispectral imager with high spatial, spectral, and radiometric performance built for the EOS-AM1 polar orbiting spacecraft. ASTER covers a wide spectral region from visible to thermal infrared with 14 spectral bands. To meet this wide spectral coverage, ASTER has three optical-sensing subsystems: visible and near-infrared (VNIR), shortwave infrared (SWIR), and thermal infrared (TIR). In addition, the VNIR subsystem has two telescopes (nadir and backward telescopes) for stereo data acquisition. This ASTER instrument configuration with multitelescopes requires highly refined ground processing for the generation of Level-1 data products that are radiometrically calibrated and geometrically corrected. The algorithm developed for the ASTER Level-1 data processing is described.
85 citations
21 Sep 1998
TL;DR: In this article, an optical system composed of dual spectrographs and a common fore-optic has been designed for the visible-near infrared (VNIR) and shortwave bands with 10-nm spectral resolution, providing 30m ground resolution from an altitude of 605 km.
Abstract: Recent advances in large format detector arrays and holographic diffraction gratings have made possible the development of imaging spectrographs with high sensitivity and resolution, ideally suited for space-based remote sensing of earth resources. An optical system composed of dual spectrographs and a common fore-optic has been designed for the visible-near infrared (VNIR) and shortwave bands with 10-nm spectral resolution, providing 30-meter ground resolution from an altitude of 605 km. The spectrograph designs are based on a modified Offner 1-X relay with spherical mirrors and a convex spherical holographic grating for the secondary mirror. The fore-optic is a three-mirror anastigmatic telescope with a 360-mm focal length to match the pixel pitch of the respective 1024 X 1024 visible silicon CCD and SWIR HgCdTe FPAs. The primary advantages of this design are the relatively low f-number (f/3), large flat field (18 mm), and low distortion. Preliminary performance results of a VNIR testbed grating and spectrograph are presented and compared to the design predictions.
17 citations
TL;DR: In this article, the high-resolution infrared spectrum of the linear centro-symmetric molecule 13 C 2 15 N 2 (cyanogen) has been measured in the region from 1950 to 2150 cm −1.
6 citations
03 Oct 1998
TL;DR: The Optical Assembly (OA) for the Multispectral Thermal Imager (MTI) program has been fabricated, assembled, and successfully tested for its performance as mentioned in this paper, which represents a major milestone achieved towards completion of this earth observing E-O imaging sensor that is to be operated in low earth orbit.
Abstract: The Optical Assembly (OA) for the Multispectral Thermal Imager (MTI) program has been fabricated, assembled, and successfully tested for its performance. It represents a major milestone achieved towards completion of this earth observing E-O imaging sensor that is to be operated in low earth orbit. Along with its wide-field-of-view (WFOV), 1.82{degree} along-track and 1.38{degree} cross-track, and comprehensive on-board calibration system, the pushbroom imaging sensor employs a single mechanically cooled focal plane with 15 spectral bands covering a wavelength range from 0.45 to 10.7 {micro}m. The OA has an off-axis three-mirror anastigmatic (TMA) telescope with a 36-cm unobscured clear aperture. The two key performance criteria, 80% enpixeled energy in the visible and radiometric stability of 1% 1{sigma} in the visible/near-infrared (VNIR) and short wavelength infrared (SWIR), of 1.45% 1{sigma} in the medium wavelength infrared (MWIR), and of 0.53% 1{sigma} long wavelength infrared (LWIR), as well as its low weight (less than 49 kg) and volume constraint (89 cm x 44 cm x 127 cm) drive the overall design configuration of the OA and fabrication requirements.
5 citations
TL;DR: In this paper, the capabilities, performances, and technical solutions of the Visible and Near InfraRed (VNIR) imaging spectrometer designed for remote sensing of planetary surfaces from a satellite platform are summarized.
2 citations
Patent•
10 Jun 1998
TL;DR: In this article, the authors proposed the utility model for spectral coverage of visible near-infrared spectrum and short-wave infrared spectrum with high quality, which is composed of a front telescope, a VNIR incidence slit, a knife-edge reflecting mirror, an SWIR prism, a press sheet, a slit seat, a bottom plate, a baffle block, a screw, an upper slide seat, an lower slide seat and a bottom seat.
Abstract: The utility model belongs to the technical field of the optics, relating to a separating device for separating the field of spectral waveband in a space remote sensing instrument. The utility model adopts a knife-edge method to carry out the separation for spectral coverage, composed of a front telescope, a VNIR incidence slit, a knife-edge reflecting mirror, an SWIR incidence slit, a press sheet, a slit seat, a bottom plate, a baffle block, a screw, an upper slide seat, a lower slide seat, a bottom seat and a spring sheet. In the wide spectral range of 0.4-25 mum, the transmitting rate of the utility model is higher than 95 percents, the spectral shake is not more than 22 percents, the spectral overlapping rate reaches 0.5 mum, and the utility model realizes the separation for the spectral coverage of visible near-infrared spectrum and short wave infrared spectrum with high quality.
1 citations
TL;DR: In this article, a nighttime OLS visible-near infrared (VNIR) channel image was overlaid on the simultaneously corrected OLS thermal infrared (TIR) image for the area around Japan.
Abstract: The OLS (Operational Linescan System) sensor on board the DMSP (Defense Meteorological Satellite Program) can observe the lights in the night. A nighttime OLS visible-near infrared (VNIR) channel image was overlaid on the simultaneously corrected OLS thermal infrared (TIR) channel image for the area around Japan. The OLS composite image showed a clear relationship between the location of fishing fleet lights detected by the VNIR channel and the sea surface temperature (SST) distribution observed by the TIR channel. Many fishing fleets were located at the cold side of boundary area of warm current and cold current. Since some types of fishes are likely to gather in certain sea temperature zones, the OLS composite image may provide useful information for the fishing fleets monitoring as well as for the marine resources management.
TL;DR: A prototype Level-1 processing software system is developed to satisfy the requirements of ASTER, a multispectral imager which covers wide spectral region from visible to thermal infrared with 14 spectral bands, and will fly on EOS-AM1 in 1999.
Abstract: ASTER is a multispectral imager which covers wide spectral region from visible to thermal infrared with 14 spectral bands, and will fly on EOS-AM1 in 1999. To meet this wide spectral coverage, ASTER has three optical sensing subsystems (multi-telescope system), VNIR, SWIR and TIR. This multi- telescope configuration requires highly refined ground processing for the generation of Level-1 data products that are radiometrically calibrated and geometrically corrected. A prototype Level-1 processing software system is developed to satisfy these requirements. System design concept adopted includes; (1) 'Automatic Processing,' (2)'ALL-IN-ONE-CONCEPT' in which the processing is carried out using information included in Level-0 data product only, (3) 'MODULE INDEPENDENCE' in which only process control module independently control other modules to change any operational conditions. (4) 'FLEXIBILITY' in which important operation parameters are set from an external component to make the processing condition change easier. The adaptability and the performance of the developed software system are evaluated using simulation data.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this article, the authors studied the distribution of the methane in the visible and infrared wavelengths since it is the main absorber in the atmosphere of Jupiter and Saturn in this wavelength range and studied the ratio between the CH 4 equivalent width and the integral of the absorption coefficient of methane at different wavelengths.