天气雷达接收机匹配滤波损耗测量方法研究

Research on Measurement Method for Matched Filter Loss of Weather Radar Receiver

天气雷达接收机匹配滤波损耗是雷达气象方程中的重要适配参数,与回波强度的测量精度密切相关。介绍了天气雷达接收机的匹配滤波原理和匹配滤波损耗的计算方法,提出了接收机数字中频匹配滤波损耗的测量方法,解释了其物理意义;并以新一代天气雷达(CINRAD/SA)为例,实测了接收机数字中频匹配滤波器的频率响应特性曲线,得到了宽、窄脉冲下的匹配滤波器带宽和匹配滤波损耗。测试结果表明:1.57μs窄脉冲对应的匹配滤波损耗为-0.93 dB,4.50μs宽脉冲对应的匹配滤波损耗为-1.01 dB。

Matched filter loss in weather radar receiver is an important adaptation parameter in weather radar equation and is closely related with measurement accuracy for returned echo. First of all,the principle for matched filtering and calculation method for matched filter loss in the receiver are introduced. Then the measurement method for matched filter loss in digital receiver is put forward and its physical meaning is explained. In addition,as an example,frequency response characteristics of matched filter in digital receiver for China New Generation Radar（ CINRAD/SA） are measured. As a result,matched filter bandwidths and losses for short and long pulses are obtained. Test results show that matched filter loss for 1. 57 μs pulse and 4. 50 μs pulse are- 0. 93 d B and- 1. 01 d B respectively.