Motion compensation method for Translational Variant Bistatic SAR using auto- correlation variance

Motion compensation is so important and difficult for Translational Variant Bistatic SAR. In this paper, at first the effects of motion measurement errors (MMEs) are discussed, and, through theoretical derivation we get that the parallel component of the absolute trajectory measurement error (AVME) and the parallel component of the relative trajectory measurement error (RVME) will cause the SAR image to severely defocus. Then the motion compensation can be implemented by 2-D searching in the directions of the composition vector of the angular velocity of T/R platforms (DOA), which needs a reasonable criterion to evaluate the quality of the image. The criterion of minimum autocorrelation variance of the image is analyzed and proved useful by simulation. At last, with this criterion, the MMEs was estimated easily by searching method, and compensated by BP algorithm.