In-flight Absolute Radiometric Calibration of the Thematic Mapper

Ground spectral reflectance and atmospheric spectral optical depth measurements made at White Sands, New Mexico were used with an atmospheric radiative transfer program to determine the spectral radiance at the entrance pupil of the LANDSAT-4 TM. Comparison with the output digital counts of the TM, when imaging the measured ground area, provided an absolute calibration for five detectors in TM bands 2, 3, and 4. By reference to an adjacent, larger uniform area, the calibration was extended to all 16 detectors in each of three bands. Preflight calibration results agreed with these inflight measurements to 6.6%, 2.4%, and 12.9% in bands 2,3, and 4, respectively.