Evaluation of analytic point target spectra for bistatic SAR

The 2-dimensional frequency domain formulation for Bistatic SAR image formation received intensive and continuous interests recently. Due to the double square roots in the range equation, additional efforts have to be taken in deriving its point target reference spectrum. Loffeld´s bistatic formula and the spectrum based on the method of series reversion are both derived for general bistatic geometries, and a few focusing algorithms have been developed by basing on them. Most recently, LBF was modified to accommodate both the motion difference of bistatic platforms and high squinted geometries. We present the numeric comparison of these two methods using the simulated bistatic data. The focusing performance of point targets and their capability of accommodating range variance are examined in this paper.