The Design And Realization Of Miniaturized Sar Real-time Imaging Processor

The available loads which mini-UAV platform carries have strictly limited in terms of weight, volume and power. So, the applicable miniature SAR must be designed for small flying platforms. The real-time imaging processor is an important component of SAR system. Generally speaking, a small flying platform can not directly transmit the SAR raw datas because of its narrow transmission bandwidth. Real-time imaging process must be completed on the platform, and then transmit the image datas to ground station. So, the real-time imaging processor with high performance, small size and low-power is the key of miniature SAR.Traditional SAR real-time imaging processor based on FPGA often used three chips for range compression, matrix transpose, and azimuth compression. Based on the characteristics and requirements of miniature SAR, this paper uses only one FPGA chip to achieve the three processes. The SAR imaging compressed complex 32bit datas are directly quantified to the 8bit gray-scale values by hardware, to further reduce the storage space and bandwidth of down datalink. The main contents of this thesis can be concluded as following:1. According to the RD algorithm and system parameter requirements, the amounts of data and computation for the processor have been comprehensive analysised. Combined with resource consumption and simulation of main modules, select an EP2S90 FPGA chip of Altera's Stratixâ…¡series.2. Detailed design imaging compression module. First divide this module into sub-modules, second parameterize FFT MegaCore and logic design for its input and output controls, the final analysis storage allocation and resource consumption in chip for this module.3. Detailed design gray-scale quantifying module. First some algorithms of gray-scale quantifying are analysised and simulated, and then the detailed designs of complex mold sub-module, quantifying sub-module and SDRAM soft-core controller is presented.4. Imaging compression module, gray-scale quantifying module and system debug and verify. And the results are given and analysised. VGA soft-core controller based on FPGA is also designed, then it successfully drive VGA interface of development board for real-time displaying SAR gray images.