Abstract: A loss of geometric accuracy of SAR images will occur after the along-track motion compensation. As a result, the sub-image connection and the multi-band image fusion will become difficult. In this paper, the expression of the geometric distortion after the along-track motion compensation is derived. Then a method is presented for geometric distortion correction. Firstly, the along-track motion error is compensated by applying the phase compensation function. Secondly, the position and the position shift of the target are determined according to the Doppler rate estiamted. Lastly, the SAR image is interpolated. Simulated data real multi-band data are used to validate this method.

Key words: synthetic aperture radar(SAR), motion compensation, geometric distortion correction, radar imaging