Doppler Parameter Estimation for Single-Channel SAR Moving Target based on a Novel Model in Complex Image Domain

Abstract

In order to characterize the signal of moving target in complex image domain (CID) of synthetic aperture radar (SAR), this paper deduces the model of moving target based on Range-Doppler imaging algorithm and stationary phase principle (SPP). In CID, the target approximately modeled as a linear frequency modulated signal (LFM), which has a great improvement in signal-clutter ratio (SCR), and distributes as mis-located segment in the 2D image. The center and slope of the segment is determined by the Doppler center and Doppler ambiguity integer. Meanwhile, the spreading length is jointly determined by the azimuth velocity and Doppler ambiguity integer. Furthermore, this paper derives the Cramer-Rao Bound (CRB) of parameter estimation in CID. At last, numeric experiments is made to approve the conclusion.