Terrain Radiometric Correction Model and Its Validation for Space-Borne SAR Data

Topography has significant influence on the geometric and radiometric properties of synthetic aperture radar(SAR)images.The terrain radiometric correction(TRC)of SAR images is one critical pre-processing step for quantitatively extracting bio-and geophysical parameters from SAR data.A TRC model and its implementation flow for space-borne imaging SAR data were introduced.The correctness and effectiveness of the model and its flow were qualitatively and quantitatively evaluated through several experimentations.By comparing two kinds of effective backscattering unit area computing methods,we found the project angle based method is much more effective than the local incidence angle based method.The rationality of computing effective backscattering unit area using initial SAR geo-location model was also demonstrated.The computational results show that the computation of local incidence angle or projection angle is not sensitive to the errors of the initial geo-model applied.Thus it is not necessary to re-compute them using the refined geo-location model.