The cosine model for correction of the terrain influences in SAR backscatter

Synthetic Aperture Radar (SAR) imagery data has been one of the most important data sources for Earth´s observation. However, terrain undulations affect the radiometric quality of SAR images. The correction of the indispensable when quantitative image analysis is performed with respect to the derivation of geo-and biophysical parameters. In this paper, a simple cosine model was proposed for the correction of terrain influences in SAR backscatter. Effects of the cosine value of three different look incidence angles on SAR backscatter were simulated based on the Advanced Integral Equation Model (AIEM), the results show that there is a good linear relationship between the SAR backscatter coefficient and the cosine value of the local incidence angle, then the semi-empirical cosine model for the correction of terrain influences was presented, the results show that the semi-empirical model was useful for the correction of the terrain influences in SAR backscatter based on the simulated data. The semi-empirical model also validated by the Advanced Synthetic Aperture Radar (ASAR) data and digital elevation model (DEM), the study area is part of Beijing mountain area. The results show that the semi-empirical model will offer help to the application of SAR data.