Abstract: In this presentation we describe flight results for anairborne IR hyperspectral imager used as a test bed forLEISA, a compact spaceborne wedged filter spectrometer.The moderate spectral resolution Linear Etalon ImagingSpectral Array (LEISA) is a low-mass, low-power,low-cost infrared spectral imager for spacecraftapplications. LEISA uses a state-of-the- art wedgedinfrared filter (a linear variable etalon, LVE) inconjunction with a detector array to obtainhyperspectral image cubes. The LEISA concept has beendescribed previously in Reuter et al., 1997, SPIE Vol.2957, pp 154 - 161, 'EUROPTO Conference on: Advancedand Next-Generation Satellites II.,' 23 - 26 September,1996, Taormina, Italy. A LEISA type instrument, theAtmospheric Corrector (LAC), will fly on NASA's EO-1spacecraft to be launched in Dec. 1999. The airborneversion of LEISA covers the spectral region from 1.0 to2.5 microns at a constant resolving power($lambda@/$Delta$lambda@) of approximately 250 (i.e. 4nm @ 1.0 microns and 10 nm @ 2.5 microns). The singlepixel spatial resolution is 2 milliradians. Thiscorresponds to 2 meters @ 1 km altitude and 20 meters @10 km. The instrument has been operated throughout thisaltitude range. The instrument has a swath width ofapproximately 29 degrees. A 256 $MUL 256 element NICMOS(Near Infrared Camera Multi-Object Spectrometer) HgCdTedetector array is used as the focal plane. The focalplane is enclosed in a small cryogenic dewar at liquidNitrogen temperature. Results will be presented forthree series of airplane flights: Lubbock Texas (USA)June -September 1997, Lubbock Texas (USA) July -September 1998, Bethlehem Orange Free State (SouthAfrica) March 1999. Issues to be discussed includepre-, and post-flight calibration, image registrationand spectral image reconstruction. The relationship ofthese measurements to future spaceborne hyperspectralimagers will also be discussed. !6
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