Analytic estimation performance bounds of downward-looking linear array 3-D SAR imaging based on compressive sensing

For downward-looking linear array three-dimensional SAR, the resolution in cross-track direction is a curial problem. Hence, compressive sensing algorithm has been used to acquire the superresolution performance in cross-track direction. The limits of the proposed algorithm are investigated in this paper. How accurately can the scattering intensity of the scatterers be estimated? What is the closest separable distance of two scatterers at different levels of SNR? What is the influence of the acquisitions N on the resolution? For all of these questions, the theoretical analysis is given by Cramér-Rao Bound and numerical simulations are proven. The results can be considered as a fundamental bound on parameter estimates.