激光大气传输特性及其回波信号仿真研究

基于Rayleigh散射和Mie散射理论,利用已有的中光谱分辨率大气辐射传输模式(MODTRAN)数据及参考模式大气(RMA)数据资料,对355nm、2μm、10μm激光信号的散射、消光、透射等大气传输特性进行了仿真和比较。同时利用高斯函数分析了355nm波长处的Rayleigh和Mie回波信号光谱分布,并模拟了不同高度处的大气回波信号光谱。结果表明:与2μm、10μm相比,355nm波长的激光信号的散射特性较好;其在大气中传输时,衰减严重,适用于晴空大气;该波段的多普勒测风激光雷达接收到的回波信号在底层以Mie信号为主,高层以Rayleigh信号为主;综合考虑各种因素,选用355nm作为星载多普勒测风激光雷达的工作波长。

Simulation research on the atmospheric transmission characteristics and the return signal for laser

Based on the theory of Rayleigh scattering and Mie scattering,the scattering,extinction,transmission and other laser atmospheric transmission characteristics at 355 nm,2 μm,10 μm are simulated and compared by using the existing moderate spectral resolution atmospheric transmittance model(MODTRAN) and reference model atmosphere(RMA) data.At the same time,the return signals of spectral distribution for Rayleigh and Mie at 355 nm are analyzed,and its spectrum at different heights is simulated by using Gaussian function.The results show that compared to 2 μm,10 μm,the atmospheric scattering characteristics of 355 nm is the best,and the 355 nm laser reduces severely when transmitting in the atmosphere,so it applies to the clear sky,and the low layer is mainly Mie signal,and the high layer is mainly Rayleigh signal for the Doppler wind lidar at that wavelength,and considering various factors,355 nm is chosen as the operating wavelength of the spaceborne Doppler wind lidar.