基于中频采样的星载合成孔径雷达的数据处理

Space-borne SAR data processing based on intermediate frequency sampling

研究了基于中频采样的星载合成孔径雷达(synthetic aperture RADAR,SAR)数据处理技术及其FPGA实现.常规星载SAR系统对模拟解调后的视频数据进行采样,然后对数据进行压缩和格式化处理并下传.采用中频采样技术实现星载SAR数据的正交解调和处理,对数字正交解调算法和合成孔径雷达BAQ压缩算法进行分析,完成FPGA的硬件设计和仿真.结果表明,基于FPGA实现星载SAR中频采样的数据处理方法可行.与传统模拟方法相比,中频采样系统性能和可靠性都有提高,是未来星载SAR数据处理的发展趋势.

We studied the scheme of space-borne synthetic aperture RADAR （SAR） data processing based on intermediate frequency sampling and the implementation method on FPGA. For a traditional space-borne SAR system, the video signal is first demodulated usually by analog method, and then sampled and compressed. This paper employs the intermediate frequency sampling technique to realize the quadrature demodulation and processing of space-borne SAR data. We analyzed the digital quadrature demodulation and the block adaptive quantization algorithms, and accomplished the FPGA design and simulation. The results show that the design scheme is feasible. Compared with the analog method, the employment of intermediate frequency sampling has improved the reliability and performance of the system, and it presents the trend of SAR data processing.