Application of RPC Model in Orthorectification of Spaceborne SAR Imagery

Abstract

AbstractIt has been widely accepted that the rational polynomial coefficient (RPC) model can be used as an alternative to rigorous sensor models of high resolution optical satellites for photogrammetric processing. In the application of the RPC model to synthetic aperture radar (SAR) image processing, it has been confirmed that the range‐Doppler model can be replaced by the RPC model. Until now, however, orthorectification with the RPC model in SAR image processing has not been considered. This paper investigates how to perform orthorectification in SAR image processing with the RPC model. Following a brief introduction about the RPC model for spaceborne SAR imagery, an optimisation model is established and a method of conducting simulations with the RPC model is proposed. Finally, a series of experiments are performed in order to verify the correctness of the theory using TerraSAR‐X, COSMO‐SkyMed, ERS‐2 and Envisat ASAR images as test data. By comparing the actual accuracy and the theoretical accuracy of the orthorectified imagery, the theory and methodology proposed in this paper are confirmed.