Surface reflectance mapping using interferometric spectral imagery from a remotely piloted aircraft

During October 1997, NASA's Environmental Research Aircraft and Sensor Technology (ERAST) Program conducted flight tests of the Pathfinder Remotely Piloted Aircraft (RPA) out of the Pacific Missile Range Facility (PMRF), Kauai (Hawaii). The Pathfinder was a light-weight (=500 lb), solar-powered RPA with an extremely limited (=35 lb) sensor payload capacity. One of the ERAST objectives was to evaluate the feasibility of using such RPA platforms to collect remotely sensed data in support of Earth systems science. A key aspect of this objective was to make simultaneous spectral measurements of a common target using an airborne spectral imager and a ground-based spectrometer. Intercomparison of these results, together with modeling of atmospheric radiative effects, enable the establishment of ground-truth and the verification of the spectral imager's radiometric calibration. The outcome of this calibration exercise is a procedure for deriving the surface albedo for a variety of different regions of the overall scene containing the ground-truth target. A Digital Array Scanned Interferometer (DASI) hyperspectral imager jointly developed by NASA Ames Research Center and and Washington University was selected as the imaging spectrometer payload. Compactness, light weight, low power draw, rugged design and simplicity of operation made the DASI an ideal candidate for this mission.