一种高效精确的FMCW SAR动静目标混合场景回波模拟方法

An Accurate and Efficient FMCW SAR Raw Data Simulation Method with Moving and Fixed Targets

近几年来,由于小型无人机的兴起,基于FMCW体制的合成孔径雷达(SAR)由于体积小,重量轻,成本低得到了快速发展。然而,由于传统的脉冲SAR中的"停-走"假设不再成立,FMCW SAR成像处理与传统的脉冲SAR有着很大的不同,这样使得在FMCW SAR实测数据进行处理和分析时往往缺乏理论支撑。因此,开展FMCW SAR的信号处理研究具有重要的现实意义和军事价值。目前,国内外关于FMCW SAR的研究主要集中在其成像处理方法上,在回波模拟方向研究甚少,特别是对于既包含分布式运动目标又有静止目标下的真实场景下的FMCW SAR回波快速模拟方法更是鲜有涉及。基于此,该文在FMCW SAR平台脉内连续运动的基础上推导了一种适用于动静目标的精确的FMCW SAR 2维频域模型,并基于该模型提出一种高效精确的FMCW SAR动静目标混合场景回波模拟的方法。点目标和场景目标的仿真试验验证了该模拟方法的有效性,效率分析发现该种模拟方法的效率远高于传统的仿真方法。

Because of compact size, light weight, low-cost, FMCW SAR develops rapidly in recent years with the rose of the small Unmanned Aerial Vehicle （UAV）. However, the signal processing methods are very different from that of pulsed-SAR due to the invalid suppose of ＂stop and go＂ and hence it is some confused in the real-data processing. Therefore, it is significant to make a deep research of FMCW SAR. However, much attention is paid on the aspect of data focusing while little research concentrates on the raw data simulation, especially for moving targets. In view of these, this paper firstly derived an accurate 2-D spectrum model in the consideration of the in-pulses motion of FMCW SAR, and then a highly-efficient raw data simulation method for FMCW SAR with moving targets is proposed. Point targets and real scene raw data simulation experiments are carried out to validate it and the its efficiencyis analyzed, results show its highefficiency comparing with the conventional methods.