| At present, more and more people focus on the research of Synthetic Aperture Radar (SAR) echo signal simulator, which is an important instrument for the design, research and test of SAR system. But the high real-time requirements and extremely large computation restricts its development. The realized SAR echo signal simulator based on point target and simple distributed target now, however, its application scopes is very limited, and requires further study and more research.According to the generation algorithms of SAR echo signal and the development of DSP parallel processing technique, algorithm research and DSP module realization are done in this thesis. The system is based on four ADSP-TS203S; the main works includes the following areas:1. The theory of SAR echo signal simulator and algorithms of RTPC (Range Time Domain Pulse Coherence) and RFPC (Range Frequency Domain Pulse Coherence) are focused on, the principle and characteristic of those algorithms are analyzed.2. The parallel processing and cooperative processing technique of multi-DSP (include synchronization, communications between DSPs etc.) are researched. The moulds such as initialization, pointer modification, table, processing, communications, Host, FPGA etc. are realized. The internal memory of DSPs is schemed and the tasks and flow of the multi-DSP system are designed. The software of all moulds is achieved in assemble language based on the environment of VisualDSP++ 4.5.3. The computation time of key modules (such as table, processing etc.) is quantitative tested. The system as well as the software of all modules is debugged, the parallel processing ability is analyzed and the imaging result is validated in Matlab.Due to the high processing ability and parallel technique of DSPs, the problem of large computation and non-real time are solved. The result illustrates that: this system we realized not only meets the requirement of project, but also is more powerful in the parallel processing ability. |
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