Geometric Correction of Spaceborne SAR Image Based on DEM and ICESat Database

The accuracy of geolocation is crucial in the application of remote sensing images. However, the presence of inevitable measurement errors consisting of antenna phase center error, slant range error, and reference height error of ground target, will result in degraded the geolocation accuracy of imaged ground targets. To improve the accuracy of geolocation, the approach of geometric correction for spaceborne SAR image is investigated in this paper. The well-known database contained digital elevation model(DEM) and ICESat data are adopted to estimate and calibrate the aforementioned errors for improving the geolocation accuracy. Validation of the proposed method is demonstrated with GF3 SAR data and high-precision GPS device.