Compensation for Distortion of Basic Satellite Images Based on Rational Function Model

The rational function model (RFM) along with basic images has been offered as the basic geometric model for further geometric processing. However, it has errors, especially nonlinear distortion errors, caused by inappropriate in-orbit geometric calibration or unreasonable geometric calibration parameters. To eliminate these errors, various RFM compensation methods have been proposed, but their application is restricted by rigorous conditions such as narrow camera field and small attitude errors. This paper proposes a generic method to eliminate nonlinear distortions of the basic satellite images. This method recovers rigorous sensor model (RSM) from RFM, then uses a traditional RSM geometric calibration method to compensate for the nonlinear distortions, and generates a new RFM from the compensated RSM. Experiments using the Gaofen-1 (GF-1) wide-field view-1 (WFV-1) sensor show that the method can raise the orientation accuracy level from several pixels to 1 pixel with ground control points (GCPs), thereby almost eliminating nonlinear distortion.