【作者】 吴明阳；

【导师】 张旭辉；

【作者基本信息】 哈尔滨理工大学 ， 测试计量技术及仪器， 2013， 硕士

【摘要】 合成孔径雷达(Synthetic Aperture Radar，SAR)是一种高分辨力的成像雷达，具有全天时、全天候、超远距离作用等工作特点。随着SAR系统向多极化、高分辨率、成像实时化的方向发展，雷达接收的回波数据量越来越大，成像时间越来越短，传统的实时成像系统解决方案已经不能满足雷达系统的实时性。本文从SAR实时成像处理技术的应用角度出发，根据某预研项目的要求，开发高性能的SAR实时成像系统。本文分析了合成孔径雷达成像的基本原理，在研究了距离多普勒算法、Chirp-Scaling算法、wk算法的基础上，选用CS算法作为系统的实时成像算法。根据系统指标要求，确定实时成像系统方案并详细论述了系统各组成部分的硬件设计。系统的硬件设计共包括包括数据采集模块、FPGA配置电路、相关接口模块三个部分。在算法实现方面，本文采用单片大容量的FPGA芯片实现CS算法。CS算法的主要步骤包括FFT、浮点复数乘法、转置存储、sinc差值等。在算法的实现过程中，FFT模块与转置存储模块是设计的难点。FFT模块采用基-4FFT算法实现，使用的大量的存储器实现流水线结构，大大提高了FFT模块的运算速度，使用Modelsim搭建仿真测试平台对FFT模块的运算结果进行精度分析。转置存储模块采用行写行读算法实现，可解决距离向压缩数据与方位向压缩数据读写速度不匹配的问题。设计完成后，选取一个场景的回波数据对整个系统进行成像测试。成像结果表明，基于FPGA的SAR实时成像系统能够对雷达的回波数据进行成像处理并具有较好的实时性。更多还原

【Abstract】 Synthetic aperture radar (SAR) is a kind of high-resolution imaging radar withthe all-day, all-weather, ultra-long-range characteristics. With the development ofSAR, the direction of which is multiplicity, high resolution and real-time imaging,the data received from the radar becomes larger and larger and the imaging timeturns to be even shorter. The traditional real-time imaging revolution cannot meet thereal-time demand of the radar system. From the application of SAR real-timeimaging processing technology, according to the requirement of a pre-researchproject, this article is aimed at developing a high-performance real-time imagingsystem of SAR.This paper analyzes the basic imaging principle of synthetic aperture radar.After researching distance Doppler Chirp Scaling algorithm, Chirp Scaling algorithmand wk algorithm, the CS algorithm is selected as the real-time imaging algorithm ofthe system. The system solution is determined according to the requirements of thesystem indicators. Discuss the hardware design of all parts of the system in detail,including data acquisition module, FPGA configuration circuit and interface modules.At the aspect of algorithm implement, this system uses a large capacity FPGA chip toimplement the CS algorithms. The main steps of CS algorithm include FFT, floating-point complex multiplication, transposition memory and Sinc difference. Thedifficulty of the algorithm module design lies in the FFT and transposition memory.The FFT module is achieved with base-4algorithm, using a lot of memory to achievepipeline structure. This structure can greatly improve the operation speed of the FFTmodule. Build a simulation test platform and use it to test the accuracy of FFTmodule. The transpose storage module adopted line write and line read algorithm toachieve, which can effective solve the match problem of range compression’s andazimuth compression’s read and write speeds. After the design, select a scene echo imaging data to do imaging test of the whole system.The actual imaging results show that the SAR real-time imaging system basedon FPGA can process the echo data from the radar and has a better real-time feature.更多还原