星载多普勒测风激光雷达小型化光学接收机

Small scale optical receiver of spaceborne Doppler wind lidar

星载测风激光雷达可以提供全球范围高实时性、高精度、高分辨率的大气风场信息,已经被认为是解决全球化风场观测的最佳手段。我国也在积极开展星载多普勒测风激光雷达相关研究工作。针对400 km高度的卫星轨道,设计并研制了一套多普勒直接测风激光雷达光学接收机,结合双边缘检测原理和星载平台相关技术参数,对Fabry-Perot标准具的主要参数进行设计。为了满足星载平台对稳定性和小型化的需求,接收机中主要光学元件之间采用分子粘接方式紧密连接。整个光学接收机集成在450 mm×300 mm×80 mm密闭箱体中,内部光学元件采用倒插方式沉入接收机壳体的凹槽内,整体结构稳定可靠,集成度高。通过改变激光波长的方式扫描Fabry-Perot标准具的透过率曲线,对所研制的接收机进行了性能测试。并由透过率曲线的实测参数对接收机的测风性能进行仿真,仿真结果显示在30 km处的最大风速误差为2.94 m/s。并进一步分析了接收机带宽增宽对测风精度的影响,分析结果显示带宽偏差为0.43 pm时,会引起1 m/s的风速误差增量。

Spaceborne wind lidar is considered to be the best means of wind field observation due to its realtime, high-precision and high resolution. Researches on spaceborne Doppler wind lidar have been actively carried out in China. The direct detection receiver of Doppler wind lidar developed for the satellite orbit with an altitude of 400 km is introduced. The receiver employs the dual Fabry-Perot etalons as the discriminating frequency unit and its parameters are specially designed for the spaceborne application. The main optical elements of the receiver are connected by molecular force and reversely inserted into the fillister of the receiver shell. The structure of the receiver is stable, reliable and highly integrated with the size of 450 mm×300 mm×80 mm, adapting to the spaceborne requirements of stability and small scale. The Fabry-Perot etalon transmission curves are obtained by tuning the wavelength of laser and the parameters of transmission curves are tested and analyzed. The wind measurement performance of the optical receiver is simulated according to the actual measured parameters. The simulation results show that the maximum wind velocity error is 2.94 m/s at the height of 30 km. Then the influence of the receiver bandwidth on measurement accuracy is further analyzed. The analysis results show that when the bandwidth deviation is 0.43 pm, the measurement error increment of 1m/s is caused.