Atmospheric correction of AVIRIS imagery in Central Switzerland. Sensitivity analysis regarding correction methods, radiation transfer models and atmospheric profiles

The retrieval of the true ground reflectance from airborne imaging spectrometer data demands the correction of the measured radiance for atmospheric absorption and scattering. In this work, these corrections were applied to data acquired during the AVIRISwiss´91 project performed in Central Switzerland. Two methods were used to correct the data, the procedure developed by Woodham and a new approach assuming a linear correlation between radiance and surface reflectance. The relevant parameters were calculated with the radiation transfer codes LOWTRAN7, MODTRAN2 and 5S. Two atmospheric profiles (the midlatitude summer profile and a profile based on actual soundings) and three horizontal visibilities characterizing the aerosol optical thickness were defined. Sensitivity analyses revealed that the crucial parameter for atmospheric correction is the visibility whereas the selection of the correction method, the radiation transfer codes and the atmospheric profile are of minor importance