Proposed atmospheric correction for the solar-reflective bands of the Advanced Spaceborne Thermal emission and Reflection Radiometer

The reflectance-based method of absolute radiometric calibration has been used successfully in the solar reflective portion of the spectrum. This method corrects for atmospheric effects by using a plane-parallel radiative transfer code. This code is intended to be modified for use in the atmospheric correction of data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) due to be launched on the Earth Observing System´s AM1 platform. The radiative transfer code numerically integrates the radiative transfer equation for a plane-parallel, horizontally-homogeneous atmosphere using Gauss-Seidel iteration. This code will be used to generate a look-up table of top-of-the-atmosphere (TOA) and surface radiance for several values of surface reflectance using given atmospheric optical depths. The atmospheric correction relies on the fact that surface reflectance and TOA radiance are linearly related for limited ranges of surface reflectance. Then surface reflectance and radiance are determined by linearly interpolating the TOA radiances measured by ASTER from the look-up-table results. Planned tests of this method are presented as well as anticipated accuracies