武汉VHF相干散射雷达及初始观测结果

摘要

Wuhan VHF(very high frequency)Radar is the first coherent scattering radar used to observe the real⁃time evo⁃lution character of the midlatitude ionosphere field⁃aligned irregularities,which locates in Wuhan University(30.5°N,114.4°E) and works at 48.2 MHz. The design of the radar system is introduced in detail,including its antenna array system,power ampli⁃fying system,receiving system,beam steering system and data processing system. The background noise fitting method is used to eliminate the RF interference,and enhance the readability of the RTI(range time intensity)figure and definition of the effec⁃tive radar echo structure. The observation results of E region field⁃aligned irregularities of the Wuhan VHF Radar show that the occurrence of the midlatitude E region quasi⁃periodic echo is caused by the K⁃H instability inspired by the wind shear.%武汉VHF雷达坐落于武汉大学（30.5°N，114.4°E），工作频率为48.2 MHz，是我国首部用于观测中纬度电离层场向不均匀体实时演变特征的相干散射雷达。首先详细介绍该雷达系统设计，主要包括天线阵系统、功放系统、接收系统、波束控制系统以及数据处理系统；然后利用噪声基底拟合方式去除射频干扰，增强RTI图的可读性和雷达有效回波结构的清晰度。武汉VHF雷达E层不均匀体的观测结果表明，中纬E层准周期回波的发生是风剪切激发K⁃H不稳定性所致。