Evaluating the Efficiency of 6S and MODTRAN5 Radiative Transfer Codes for Absolute Atmospheric Correction of TM Multispectral Images

Due to absorption and scattering by gases and aerosols, the reflected radiance from ground surface changes when passing through the atmosphere before getting captured by the remote satellites. The absolute image atmospheric correction is the prepossessing step that reducesatmospheric effects. These corrections improve satellite image quality and increase processing performance of such images. Many absolute image atmospheric correction methods use radiative transfer code procedures. In this paper, the potential of two well-known code 6S and MODTRAN5 in absolute imageatmospheric correction of TM images was studied. Atmospheric correction results investigated via visual inspection of Top of Atmosphere (TOA) and surface reflectance values were extracted by two methods.Also the quantity of information variation in spectral images was investigated by Entropy, Range and Standard deviation criteria. The results clearly show that correction of atmospheric effects in visible spectrum and infrared spectrum appears with negative and positive signs respectively. Also the differences between utilized codes illustrated in surface reflectance were observed in infrared spectrum. Moreover, both codes (6S and MODTRAN5) improve quality of imageregarding TOA reflectance image with 12% and 23% in Mean Range and 5% and 6% in Entropy respectively.