Bistatic Sar Imaging Algorithm With The Measured Data Processing

Bistatic Synthetic Aperture Radar uses separated transmitter and receiver flying on different platforms, which has several advantages like ability to obtain rich information, long operating distance, high security, capability of anti-jam, et al. Based on the first pair of domestic Bistatic SAR experiment, the paper's main contents are as follow:Imaging mechanism is investigated. The general geometry and signal models of Bistatic SAR are built firstly. Based on the general geometry model, range history and Doppler properties are disgussed in detail. the spatial resolutions of bistatic SAR have been derived from the ambiguity function.Imaging algorithms of bistatic SAR are investigated. In the case of Translationally invariant bistatic SAR geometry, bistatic RD algorithm, bistaticωk algorithm and bistatic BP algorithm are researched. For the bistatic RD algorithm, bistatic SAR echoed signal is modeled in the double range variables domain. A range-dependent Doppler algorithm for the translationally invariant configuration is derived, by mapping the signal model to the single range variable domain. Also, the principle and flow chart of the bistatic BP and bistaticωk algorithm are given. The effectiveness of the algorithms is proved by processing simulation and real data. the imaging algorithms for computing performance and computation were compared.Because Doppler parameters estimation is a essential step in bistatic SAR imaging algorithm. This paper studies the greatest contrast algorithm, and minimum entropy based on the discrete Fourier FM Doppler parameter estimation algorithm, through the real data processing in the translationally invariant configuration prove the validity of two algorithms, and two Doppler parameter estimation algorithms are compared. At the same time, a new bistatic SAR T/R relative speed estimation method using nadir echo is present. The algorithm uses the Doppler of nadir echo and the relationship between the relative velocity platform, through time-frequency analysis tool to estimate the relative velocity platform, and the relative speed of the platform is used for bistatic BP in the image motion compensation. Finally, bistatic SAR imaging algorithm of translationally variant geometry is researched: 2 - D ISFFT imaging algorithm. The algorithm is based on the LBF model, through inverse scaled Fast Fourier Transformation to realize the translationally variant bistatic SAR imaging. The effectiveness of the algorithms is proved by processing both cases translationally variant geometry simulation. Finally degradation of the algorithm for Translationally invariant geometry, applied to the real data processing.