Application of terrain radiometric correction in polarimetric SAR imagery classification

Primitive SAR imagery exists serious geometric and radiometric distortions,e.g.foreshortening,layover and shadow,due to the effect of SAR imaging geometry and the topographic relief.Among them,layover regions usually reflect strong backscattering return.This phenomenon easily leads to the misclassification between forestland and habitation so that it decreases the classification accuracy for polarimetric SAR imagery classification.This paper presented a terrain radiometric correction method to solve this problem,which uses the projection angle to compute theγ0backscattering coefficient.Then one scene of Quad-polarization Radarsat-2imagery was used to verify the validity of the method,and a complex Wishart supervised classification method was applied to classify the polarimetric SAR images prior to and after terrain radiometric correction,respectively.The classification results showed that the classification accuracy of polarimetric SAR images would be improved and increased from 87%to 92%after processing with the proposed method.