Nonlinear Trajectory SAR Imaging Algorithms: Overview and Experimental Comparison

The nonlinear characteristics of the motion trajectory of the synthetic aperture radar (SAR) flight platform can lead to severe two-dimensional space-variance characteristics of the signal, greatly affecting the imaging quality, and are currently considered as one of the difficulties in the field of SAR imaging. This paper first discusses the nonlinear trajectory SAR model and its space-variance characteristics and then discusses algorithms such as scaling-based algorithms, interpolation-based algorithms, time-domain algorithms, and hybrid algorithms. The relative merits and applicability of each algorithm are analyzed. Finally, computer simulation and actual data validation are conducted.