Recent developments in ATCOR for atmospheric compensation and radiometric processing of imaging spectroscopy data

Recent developments in atmospheric compensation are summarized in this paper with emphasis on algorithms implemented in the ATCOR model. First, achievements and current limitations in haze and aerosol detection and correction as well as in BRDF correction are outlined. Secondly, correction approaches for high resolution spectral variations in the reflectance outputs are described. The inherent problem of high resolution imaging spectroscopy is that smallest spectral variations of the instrument response during data acquisition, radiative transfer model errors in atmospheric gas absorption, and errors in the employed solar irradiance spectrum lead to significant spectral variations after atmospheric compensation. Applying spectral recalibration and using air pressure dependent processing is shown to improve the comparability of the radiometrically corrected reflectance data to the ground measurements and to modelled spectra. Remaining open issues are the aerosol scattering compensation below 420 nm wavelength, the model-based BRDF correction in rugged terrain, and the correct consideration of spectral band width during processing.