星载激光多普勒测风雷达鉴频系统仿真(Ⅱ):基于Fabry-Perot标准具的Rayleigh通道大气风速反演研究

Simulation of frequency discrimination for spaceborne Doppler wind lidar(Ⅱ):Study on the retrieval of atmospheric wind speed for Rayleigh channel based on Fabry-Perot interferometer

基于星载激光多普勒测风雷达工作原理,构建了基于连续双通道Fabry-Perot(F-P)标准具的鉴频仿真系统,仿真研究了Rayleigh通道大气风速反演算法,系统分析了Rayleigh-Brillouin效应和Mie干扰信号对Rayleigh通道反演大气视线(LOS)风速的影响,并利用无线电探空数据集仿真结果统计分析了Rayleigh通道大气水平视线(HLOS)风速反演误差.结果表明,基于连续双通道F-P标准具的Rayleigh通道可反演中高层大气风速;Rayleigh-Brillouin效应和Mie干扰信号影响Rayleigh通道LOS风速反演精度;Rayleigh通道风速反演对温度精度要求最高,在晴空条件下可忽略Mie干扰信号的影响;不考虑Brillouin效应时,高度2 km以下Rayleigh通道无法反演HLOS风速,高度2 km以上Rayleigh通道反演的HLOS风速误差小于0.4 m·s-1,风速标准差在1—4 m·s-1之间;同Mie通道一样,气溶胶和云的分布影响Rayleigh通道HLOS风速反演误差.研究结果对发展星载激光雷达测风技术具有重要参考意义.

Based on the principle of spaceborne Doppler wind lidar, a simulation system of frequency discrimination is built based on the double sequential Fabry-Perot（F-P） interferometer. The wind retrieval algorithm of Rayleigh channel is simulated and studied. The influence on the retrieved atmospheric line-of-sight（LOS） wind speed in Rayleigh channel by the Rayleigh-Brillouin effect and Mie contamination is systematically analyzed. The horizontal line-of-sight（HLOS）wind error is analysed using the simulated result of the radiosonde dataset. The results show that the wind speeds of the middle and upper atmosphere can be retrieved in Rayleigh channel based on the double sequential F-P interferometer; the Rayleigh-Brillouin effect and Mie contamination influence the accuracy of LOS wind speed retrieval in Rayleigh channel;the Rayleigh channel requires more accurate temperature; Mie contamination can be ignored in clear atmosphere; when Brillouin effect is not considered, below 2 km, the HLOS wind speed cannot be retrieved in Rayleigh channel, and above2 km, the HLOS wind speed error in Rayleigh channel is less than 0.4 m·s-1and its standard deviation is 1–4 m·s-1.Just as the Mie channel, distributions of aerosol and cloud have an influence on wind error for spaceborne Doppler wind lidar in Rayleigh channel. The research results have an important reference value for the development of spaceborne lidar wind technology.