Research And Implementation On The Real-time Signal Processing Of Airborne SAR/GMTI

Airborne high resolution SAR/GMTI real-time imaging technology is a very effective remote sensing tool, and performs more and more important function in the civilian and especially military applications areas.Based on the project research, this paper studies the theory and hardware implementation of the airborne SAR/GMTI imaging system.Firstly, the basic principle and system modeling of side looking SAR are explained from views of pulse compression, synthetic aperture and Doppler resolution. And the system modeling of bistatic SAR is presented as well.Secondly, the implemented strip map SAR real-time imaging processor based on RD algorithm is presented. The basic principle, operation burden and implementation of the processor are introduced in detail. At the same time, real time implementation of CS algorithm is also discussed.Thirdly, the real time single and dual channel GMTI algorithms with continuous sub-aperture processing are derived. And the real time implementation of GMTI with high speed DSP platform is presented.Finally, the phase error and negative effect to SAR image are introduced and analyzed. Then a cascade auto-focus algorithm, which includes range direction motion compensation and azimuth motion compensation with QPGA for estimating phase error of SAR raw data and improving SAR images, is presented and derived. Then the real time implementation of the auto-focus algorithm is presented as well and the effect is evaluated.