Range-Doppler Approach for Calibration and Location of Air-borne SAR Image

This paper investigates calibration and location of air-borne Synthetic Aperture Radar (SAR) image without Ground Control Points (GCPs). The position of each pixel in the image lie on the geometric relationship between antenna and each scatter cell. In order to reduce the reliability on the stability of flying attitude of the airplane and improve the real-time performance of imaging algorithm, time-domain sub-aperture imaging algorithm is often used in air-borne SAR in practice when the range and azimuth resolutions are not too high. It can obtain the Doppler frequency of each pixel in the image and lay the foundation for the range-Doppler location approach, which obtains coordinates of each pixel in SAR image by means of slant range and Doppler equations. The effectivity of the location approach is validated by simulation experiment and flying trial.