FPGA实时多普勒中心频率估计  

FPGA Real-Time Doppler Centroid Estimation

作　　者：甘翼[1] 李向阳 GAN Yi;LI Xiang-yang(The 10th Research Institute of China Electronics Technology Group Corporation,Sichuan Chengdu 610036,China)

机构地区：[1]中国电子科技集团公司第十研究所

出　　处：《现代防御技术》2019年第5期57-64,共8页Modern Defence Technology

摘　　要：基于弹载合成孔径雷达(SAR)对成像精度、处理时间、资源使用效率和设备低功耗的更高要求,提出一种基于FPGA的多普勒中心频率估计方法,采用FPGA实现实时高精度多普勒中心频率估计。改进回波处理流程,在距离向脉冲压缩过程中,距离向脉冲压缩结束后即可完成多普勒中心频率估计,进行后续距离走动校正(RCMC),实现了SAR信号处理机的“零等待”。在算法实现过程中,提出了基于FPGA的流水线式相位解缠绕方法和基于最小二乘的参数曲线拟合算法,实现相位解缠绕的连续流水输出以及中心频率估计参数精确插值。通过试验验证,基于FPGA的多普勒中心频率估计方法,充分发挥了处理资源使用效率,使SAR信号处理机硬件相对以前减少80%以上,处理时间和频率估计精度均优于系统要求。Along with the development of missile-borne synthetic aperture radar (SAR),the imaging precision,speed for processing,efficiency of resources usage and low-power demand in SAR are required higher and higher.A method based on field-programmable gate array (FPGA) to estimate Doppler centroid is proposed,which is able to give real-time and high precision estimation. The echo processing is improved.In the range direction pulse compression process,Doppler centroid is estimated at the completion of the range direction pulse compression.By using range cell migration correction (RCMC),“no-waiting” is implemented in SAR signal processor.In the algorithm implementation processes,FPGA-based pipelined phase unwrapping method and least-square based parameter curve fitting method are proposed,implementing continuously phase unwrapping output and centroid estimation parameters approximately interpolation.It is verified by the experimental results that the estimation method is able to utilize the FPGA resources efficiently.The speed and accuracy of method satisfy the requirement with SAR signal processor hardware reduction of more than 80%.

关 键 词：多普勒中心频率估计 现场可编程阵列 合成孔径雷达 回波处理 相位解缠绕 最小二乘 

分 类 号：TJ76[兵器科学与技术—武器系统与运用工程] TN958[电子电信—信号与信息处理]