基于双通道可调F-P干涉仪的机载测风激光雷达系统的鉴频器

An airborne wind lidar system's frequency discriminator based on a dual channel tunable Fabry-Perot interferometer

利用双通道可调Fabry-Perot干涉仪作为机载测风激光雷达系统的鉴频器。该鉴频器可以克服现有测风雷达测速范围小的缺点,能够根据相对风速变化调整干涉仪的腔长,从而达到调整干涉仪透射谱中心频率的目的,从而间接实现测速范围动态可调,扩大测速范围的目的。采用此鉴频器可以实时测量飞行器与大气的相对风速。文中详述了测速原理和鉴频器结构,并给出机载雷达的系统参数,分析了系统的测量误差,结果表明：探测累积时间1s,测速范围为0～1000m/s时,探测高度可达30km,系统测量误差小于5m/s。

A dual channel tunable Fabry-Perot interferometer is used as a frequency discriminator in an airborne wind lidar system.The exiting frequency discriminator couldn＇t be used to measure so high velocity range.This new frequency discriminator based on the dual-channel tunable Fabry-Perot filter has been proposed.The approach discussed here adjusts the cavity length to change the centre frequency of the interferometer.By this way,the velocity can be detected and cut into several dynamic range.Use of this discriminator can be real-time measurement of the relative wind velocity between air and aircraft.This paper has completely summarized the detection theories and also introduced the structural design of the frequency discriminator.In the end an airborne lidar at 266nm using reasonable instrumental parameters are simulated to investigate the performance and the accuracy of the system.The simulated results show the error in the velocity dramatic range of 1000m/s is less the 5m/s up to 30km.