法布里-珀罗环转线系统的测风激光雷达技术与数值仿真

Numerical simulation of wind lidar based on Fabry-Perot circle-to-line interferometer optical system

设计了基于法布里-珀罗(F-P)条纹技术的非相干多普勒测风激光雷达系统,采用环转线干涉仪光学系统(CLIO)将F-P形成的环状条纹转换成线性条纹成像到具有高量子效率的CCD探测器上进行检测,克服了环状条纹与传统阵列式探测器不匹配的缺点并改善了探测系统的信噪比。采用光学设计软件ZEMAX对该系统进行了光学设计和数值仿真,得到了用于反演风速的不同波长干涉条纹图样,并对重心法和Voigt函数拟合法两种主要的风速反演方法进行了对比讨论。结果表明:用Voigt函数拟合法反演风速误差较小,获得风速在20 m/s时的误差小于0.5 m/s,验证了该系统的设计及数据反演算法的可行性,为测风激光雷达的进一步研制提供了理论依据。

Incoherent Doppler wind lidar system was designed based on Fabry-Perot （F-P） fringe technique. The circular output from a F-P interferometer was transformed to a linear pattern by using a circle-to-line interferometer optical （CLIO） system and then detected by CCD with high quantum efficiency, which corrected the mismatch between circular fringes and conventional array detectors and improved the signal-to-noise ratio of the system. Using ZEMAX software, the CLIO system was designed and simulated numerically, and the fringe patterns at two different wavelengths were obtained and discussed by two different wind velocity retrieval methods, corresponding to Gravity method and Voigt function fitting method. The results show that the wind velocity error is smaller by Voigt function fitting method. It is less than 0.5 m/s at the wind velocity of 20 m/s, which validates the feasibility of the system and data retrieval method. It supplies numerical foundation for wind lidar system.