Spaceborne SAR imaging by exact compensation of the attitude errors

When the space-borne SAR works on the low-stability platform, the Doppler parameters (Doppler centroid and Doppler frequency rate) show variations during the azimuth illumination time, except that the variation of the Doppler parameters as a function of the range distance. That is to say, the azimuth reference function is two-dimensional variant (in range distance and azimuth), the conventional clutter lock and auto- focus for estimation of Doppler parameters are not sufficient for imaging. A model-based algorithm is proposed to exactly compensate the error introduced by the platform attitude instability, the efficiency of the algorithm is tested with computer simulation.