合成孔径雷达相干性分析  

Coherence Performance Analysis of the Synthetic Aperture Radar

作　　者：田栋轩[1] 王万林[1] 李刚[1] TIAN Dongxuan;WANG Wanlin;LI Gang(Xi’an Institute of Space Radio Technology,Xi’an,710100)

机构地区：[1]西安空间无线电技术研究所

出　　处：《火控雷达技术》2019年第3期37-41,共5页Fire Control Radar Technology

摘　　要：合成孔径雷达是一种相干雷达,相干性是保证合成孔径雷达方位向成像性能的关键核心因素之一。文章剖析了相干性的内涵,从合成孔径雷达系统的角度,分析了相干性的影响因素和保证相干性的具体措施。为了保证合成孔径雷达的相干性,在频点分配上,确保产生定时脉冲的参考时钟是产生雷达发射线性调频信号参考时钟和AD采样时钟的最大公约数,系统上变频和下变频采用相同频点的本振,应根据成像性能要求合理确定频率源的短期稳定度指标,系统中相同频点的多路信号采用无源功分的方式产生。本文建立了系统仿真分析模型,通过仿真计算和实验测试的方法验证了保证相干性措施的正确性。Synthetic Aperture Radar(SAR)is a type of coherent radar,in which coherence is one of critical characteristics to guarantee the SAR azimuth imaging performance.This paper describes the concept and connotation of the coherent in SAR,and then analyses the influencing factor of coherent in SAR and measures to ensure coherence from a systematic perspective.In system frequency distribution,to ensure the coherent of SAR,the reference frequency used for timing should be the largest common divisor of the frequency used for linear frequency modulation signal source and A/D sampling;and up and down converter of the system for should use local oscillator with same frequency.The parameters of oscillator instabilities should be set reasonable in accordance with the requirement of the SAR system.The same frequency for multi-channel application is supposed to be produced by the passive power divider.The simulation model is established and applied for the experiment.The result shows the validity of the proposed coherent assurance technique.

关 键 词：合成孔径雷达 相干性 分析 

分 类 号：TN95[电子电信—信号与信息处理]