频率源对雷达测速精度影响分析

摘要

针对高稳频率源如何影响雷达测速精度问题,构建基于频率源分析雷达测速精度的理论模型,利用同步校频和互备双锁相环(PLL)改进方案实现了高稳高可靠频率源,然后通过静态模拟试验和动目标跟踪试验,分析频率源幅度、准确度、稳定度及同步校频、锁相环等模块对多普勒和测速精度的影响.结果表明,锁相环能够提升频率源短稳,降低雷达测速随机误差,同步校频能够减小本地铷钟与外部基准的频差,减小雷达测速系统误差,通过双源和双锁相环的设计,频率源切换或锁相环路切换时,也能够保证测速雷达系统正常工作.%Focusing on the high velocity measurement accuracy of a Doppler radar,a theoretical model is constructed based on the frequency source;a highly stable and reliable frequency source is achieved using the new method of synchronous calibration and dual phase-locked loop (PLL);then through the simulation experiments and the moving target tracking experiments,the influence of the frequency source amplitude,accuracy,stability,synchronization frequency calibration and PLL on the Doppler and velocity accuracy is analysed.The results show that the PLL can improve the short stability of the frequency source,reduce the radar velocity random error;synchronous calibration can reduce the frequency difference between the local rubidium clock and the external reference,reduce the radar system error;the design of the internal and external dual sources,interlocking phase-locked loop and automatic switching can ensure that the velocity measurement radar work properly when the reference sources switch or the dual PLLs switch.