Geological Mapping Using Morphological Characteristic of Lithostratigraphic Units through Radar Remote Sensing

Abstract. Traditional field-based methods for geological mapping have become obsolete and are now primarily used for quality control purposes. Geological maps at various scales are currently generated using remote sensing technologies and satellite image processing. In optical remote sensing, only hyperspectral images are typically employed for geological purposes; however, due to their limited spatial resolution, fieldwork is still required to supplement morphological and lithological information. Synthetic Aperture Radar (SAR) data, as part of microwave remote sensing, provide surface geometry and allow discrimination of alteration zones based on material composition. To achieve this, backscatter modeling of radar waves according to surface material and roughness is essential. Several models, ranging from theoretical to semi-empirical, have been proposed for this purpose. This study evaluates the effectiveness of surface geometry modeling and its impact on the accuracy of alteration zone delineation in the geological structures of Khourmoj, Kuh-e Siah, and Khartang. Based on the computations, the deviation between radar-based alteration zone delineation and ground truth is estimated at less than 10% for formations with rugged lithology and around 25% for those with softer lithological compositions. Overall, this method is strongly recommended as a substitute for field surveys in the final stages of geological map production following spectral analysis.