Research On SAR Real-Time Parallel Imagery System

The problems related with the algorithm of the real time processing of SAR images and design, development and testing of real time SAR processor are studied in this thesis.Chirp Scaling algorithm for parallel processing of SAR raw data was designed and applied with Dawn2000-II, which is a grand parallel computer. According to the results of the simulation, the optimized number of nodes needed for computing was presented for different data volume. The real time image processing systems are also simulated with the algorithm in this thesis.For improving the SNR and the reducing transmit power of the SAR simultaneously, airborne SAR often use high PRF (Pulse Repetition Frequency). In order to decrease the band of the digital signal and restrain the energy of the overlap spectrum of the alias, the desample filter was applied to the real time image processing. The thesis not only provided the Lagrange multiplier algorithm for designing the desample filter, but also the algorithm was designed to take account the effect of the antenna pattern of the SAR used in collecting the raw data.Based on the processing data flow in the SAR real-time processor, the thesis gave the way to implement auto-focus algorithm in the system. Moreover, the application of CS algorithm in the real-time system was also analyzed in the thesis.The application of Real-time Operating System (RTOS) to the SAR real-time processor was studied by comparing RTOS with normal OS. The method of choosing RTOS for the real-time system was provided based on the analysis.In order to debug and verify the whole SAR real time processor7 the authordesign and developed a PCI card as a real-time radar signal source. With the card, the data could be transmitted from PC hard disk to the SAR real-time processor through PCI Bus. There were two parts, hardware and software, for developing the card. The Development of hardware and software was presented in the thesis.