Real-time Synthetic Aperture Radar Imaging Technology To Study

Airborne SAR could gain high-quality image during aircraft flight. Due to its theoretical advantages, SAR imaging has been widely applied in both military and civilian areas. Range and azimuth compression are the two crucial steps of SAR imaging. The major challenges of real-time implementation with digital signal processing techniques lie in the algorithm complexity and high data rate of Radar.With the tremendous development of microelectronics technology, the performances of digital signal processor increase rapidly in recent years. The peak performance of the latest float point DSP -TMS320C6701, manufactured by Texas Instruments Inc., reaches 1GFLOPS. Higher-speed DSPs extend possibilities to design more reliable, functional and compact Radar signal processing systems.This thesis presents a high-speed DSP system based on TMS320C6701 DSP to real-time implement azimuth compression. Experimental simulation and field flight have proved that this system is successful.At first, the histories, present development, classification of SAR are reviewed. Then, the SAR imaging principles are studied. Some crucial issues, such as model of echo, resolution and range migration are explained and the standard RD imaging algorithm is deduced. Then the paper present two latest technologies in real-time signal processing: DSP and FPGA. Their basic structure and design methods are discussed. After that, the paper describes the structure of a real-time SAR imaging system, which was produced by Institute of Electronics, Chinese Academy of Sciences. Analysis of azimuth compression steps and processing load leads to a new azimuth processing system, which was designed based on TMS320C6701 DSP. The details of its hardware and software design are narrated.