Phase Center Extraction of Corner Reflector Points in Single-Look Complex Image

The geometric calibration accuracy of the Synthetic Aperture Radar (SAR) system is affected by the extraction accuracy of Corner Reflector (CR) points in a Single-Look Complex (SLC) image. There are some problems in traditional artificial extraction methods for CR points, such as the difficulty of identifying CR points without prior knowledge, low efficiency, and limited extraction accuracy. An extraction method of the phase center for CR points without prior knowledge was proposed in this paper through the construction of a geometric error compensation model for SAR images and the study of high precision fitting methods of the phase center for CR points. The effectiveness of the proposed method was verified by the Gaofen-3 (GF-3) satellite image data. Experimental results demonstrated that the extraction accuracy of CR points could be better than 0.2 pixel for GF-3 images.