光源线宽对相干激光测风雷达探测性能的影响分析

使用窄线宽激光源是相干激光测风雷达的特点之一，为研究不同线宽光源对激光测风雷达探测性能的影响，从理论分析了在相干长度内、外时光电流的频谱特性，并使用了三种不同线宽的激光光源进行实际的测风试验。试验表明，当探测距离在相干长度外时，100 kHz光源信号幅度较1 kHz与10 kHz两种光源下降约30%，且部分频段噪声幅度较大。因此，在设计中近程激光测风雷达，可考虑选用百kHz量级线宽光源，而探测距离数千米甚至更远的中远程激光测风雷达，可考虑选取几十千赫级线宽光源。

Influence of light source linewidth on detection performance of coherent wind lidar

One of the characteristics of coherent wind lidar is using narrow linewidth laser source. In order to study the influence of different line width light sources on the detection performance of lidar, the spectrum characteristics of the time current in and out of the coherent length were analyzed theoretically. Experiments show that when the detection distance was outside the coherent length, the signal amplitude of 100 kHz light source was about 30% lower than that of 1 kHz and 10 kHz light source, and the noise amplitude of some frequency bands was larger than that of the other two light sources. Therefore, in the design of short-range wind lidar, hundreds of kHz light source could be considered, while in the medium and long-range lidar with detection distance of several kilometers or more, tens of kHz light source could be considered.