Airborne Bistatic Synthetic Aperture Radar System Synchronization Issues

The separate platforms and indeterminate aviation of the platforms, which result in more complex of the Airborne Bistatic Synthetic Aperture Radar (Bistatic SAR) system synchronization. The study of Synchronization technique including many sides such as system design, compensation based on hardware, compensation based on algorithm etc. The synchronization technique of time and phase is the key of this paper.The geometry, echoed signal models and the memory form of echoed data of airborne bistatic SAR in general flight configuration are introduced. The theory of SAR imaging and RD imaging algorithm of bistatic SAR are studied.Time in the SAR imaging is divided into fast time and slow time. Modeling and analyzing the effect for imaging when added different modality errors, the simulation result and errors criterions are given. This paper analyzes the two key sources of phase errors, motion errors and oscillator errors. Modeling and analyzing the effect for imaging when added different modality errors in 3 different courses, giving the simulation result and errors criterions. Modeling the oscillator errors, this divided into 3 different errors and analyzed. These offer the theoretical basis for synchronization system design.Uncorrelative two-way time transfer way counteracts part of errors of system and the transfer way, can get high precision of time synchronization, it's a well way. Contrast to it, this paper propose a phase synchronization way—two-way phase transfer way, which using the difference of phase difference to compensate phase errors. At last give a synchronization system fram that based on these two two-way transfer ways.An improved ML-PGA algorithm for bistatic SAR phase compensation is proposed, which is using contrast optimization way to choose lines of range, using average value to get widths of the window, using iterated phase estimator to get phase grads value. Using pulse chasing space synchronization for airborne bistatic SAR been suggested, and motion compensations based on GPS/INS/IMU control system is studied.