Dual-based Synthetic Aperture Radar Imaging Algorithm

Bistatic Synthetic Aperture Radar (SAR) can image in flight direction or backwards with the choice of proper geometry. This ability leads the SAR technology can be used in the aircraft autonomous landing, scene matching guidance and other fields. The blind spot of traditional SAR imaging problem is solved effectively.Focusing on the imaging theories of bistatic forward-looking SAR with one fixed station and bistatic forward-looking SAR with T/R moving together, the main work of echo model, point target response function and imaging method is shown as follows:1. The geometry and echo model of bistatic forward-looking SAR are presented; The range history properties are analyzed; the point target response and two dimensional (2D) spectrum are derived. The large range migration and the strong coupling properties are revealed. And it lays a theoretical foundation for algorithm design.2. The BP algorithm has been researched. It achieved accurate SAR imaging. The advantages, disadvantages and application of BP algorithm are analyzed.3. An imaging algorithm named SIFFTA (Scaled Inverse Fast Fourier Transform Algorithm) for bistatic forward-looking SAR with one fixed station is proposed. Large range migration and strong coupling in 2D spatial varied cases are solved.4. SIFFTA for bistatic forward-looking SAR with T/R moving together is proposed. The signal model based on time domain equivalency is derived for the complexity of the 2-D spectrum. Fast imaging is realized in 1D spatial varied case.The feasibility of algorithms and imaging performances are validated by simulation.