俯视电波折射修正及其在俯视雷达信号接收中的应用

Refraction correction for downlooking radio wave and its application in the signal reception for downlooking radars

针对海洋上空大气折射环境影响下岸基俯视雷达信号的舰载机动接收有效方法进行了系统研究.根据实际需求,建立俯视雷达信号在海洋上空传播的物理模型,通过射线追踪法结合Hopfield折射率剖面模型,仿真计算获得了大气折射影响下的电波实际传播路径,并与Ray-VT射线追踪软件的计算结果进行比对,四种发射参数下的水平距离相对偏差分别为-0.002%、-0.041%、-0.029%、-0.007%,初步说明了电波传播路径仿真的准确性.经过仿真,发现海洋上空大气折射环境对岸基俯视雷达信号的舰载接收有很大影响,必须对接收位置和接收仰角加以修正.

This paper studies an effective shipboard maneuvering receiving method for shore-based down-looking radar signal influenced by atmospheric refraction environments over the ocean.According to the actual demands,a physical propagation model of down-looking radar signal over the ocean is established.Using ray tracing method and Hopfield refractive index profile model,this paper simulates the electromagnetic wave propagation path influenced by atmospheric refraction environments.Compared with the calculation results of Ray-VT ray tracing software,the relative deviations of the horizontal distance under four emission parameters are-0.002%,-0.041%,-0.029%,and-0.007%,respectively,which preliminarily illustrates the accuracy of simulated propagation paths.It is found that the atmospheric refraction environment over the ocean has a great influence on the effective ship-based reception of the shore-based down-looking radar signal.Therefore,the receiving position and pitch angle must be corrected.