The LEISA/Atmospheric Corrector (LAC) on EO-1

The LEISA (Linear Etalon Imaging Spectral Array) Atmospheric Corrector (LAC or AC) on EO-1 is a hyperspectral imager providing 256 channel continuous spectra in the wavelength range from 0.93 to 1.58 microns. It has a single pixel spatial resolution of 250 meters, a 185 km swath-width and a spectral resolving power (/spl lambda///spl Delta//spl lambda/) of 200 or greater (<10 nm) throughout its spectral range. The imager employs a wedged filter, a sophisticated 2-dimensional filter whose transmission wavelength varies along one of the dimensions, to provide its spectral resolution. The use of the wedged filter greatly. simplifies the optical/mechanical design, so that the instrument is adaptable to a wide variety of platforms (i.e. it is a "bolt on" imager). In this paper we shall present an overview of the camera highlighting its unique features from both a design and data standpoint. We shall discuss the pre-launch instrument characterization process and on-orbit performance. This shall include the use of solar and lunar calibration techniques to obtain absolute radiometric calibration. The application of the data to the problem of atmospheric correction of high-spatial resolution multi-spectral satellite images (e.g. Landsat-type) shall be discussed.