Various techniques can be grouped under the heading radiometric correction, which aims to correct for various factors that cause degradation of raw RS data. Radiometrically correcting data should make them more suitable for information extraction. Techniques for modifying recorded DNs serve any of the three main purposes below:
Enhancing images so that they are better suited for visual interpretation;
Correcting data for imperfections of the sensor;
Correcting data for scene peculiarities and atmospheric disturbances;