Parameter estimation for SAR moving target in complex image domain

Based on the proposed parametric model of SAR ground moving target in the complex image domain, this paper derives the Cramer-Rao bounds (CRB) for the unknown model parameters estimation and obtains the inherent limitations for the moving target motion estimation in the SAR complex image domain. Firstly, the relationships are analyzed among the estimation performance and the target's scattering intensity, Doppler parameters, motion parameters, as well as the power spectra of the target and the clutter. Furthermore, the parameter estimation performance is compared in the signal domain and the complex image domain (CID) to draw some useful conclusions. Besides, the reduction resolution processing is proposed to improve the parameter estimation, and its performance improvement is also presented with analytic expressions. For the homogeneous background, it is shown that the accurate parameter estimation and azimuth location may be realized for SAR ground moving target in the complex image domain. Finally, some numerical experiments are provided to demonstrate the effectiveness of the proposed methods.