Effect of Atmospheric Characterization on the Reflectance-based Vicarious Method of Radiometric Calibration of Landsat 7 ETM+

摘要

The reflectance-based method of radiometric calibration has been used by the Remote Sensing Group (RSG) to radiometrically calibrate the Landsat series of earth observing satellites starting withLandsat-4 and -5 TM and leading to the current work with Landsat 7 Enhanced Thematic Mapper (ETM+). The method has been applied to almost 70 sets of ground-based reflectance and atmospheric data for large desert test sites used by RSG for the calibration of Landsat 7 ETM+. The current work examines effects of atmospheric uncertainty on the vicarious reflectance-based radiometric calibration of Landsat 7 ETM+. Historical atmospheric characterization data are usedto construct an average atmosphere attwo individualRSG test sites. The combination ofanaverage atmosphere and overpass surface reflectance values allows a band-by-band analysis of the effects of atmospheric characterization on the precision of the resulting radiometric calibration. The results using average conditions are compared to results obtained using the atmospheric characterization parameters from a specific date. Results show that atmospheric variability is not the primary cause of thy-to-thy variability at high reflectance sites. These results indicate that precise results for the radiometric calibration of earth-observing sensors over the selected test site regions can be obtained through use of an average atmosphere in the radiative transfer code as long as an accurate surface reflectance is available.