直接测风激光雷达频率跟踪技术及对流层平流层大气风场观测

为了实现高精度连续探测对流层和平流层大气风场，搭建了一台直接测风激光雷达系统对对流层和平流层大气风场进行探测。该系统基于双边缘法布里-珀罗标准具的瑞利散射多普勒测风原理，使用转台式探测结构，通过频率跟踪的手段对频率漂移进行跟踪，确保测风的精度。实验结果表明，该系统对对流层和平流层大气风场探测效果良好，频率跟踪的范围为±50 MHz，可以大大减小频率漂移带来的风速误差。经过系统的稳定运行和长时间的观测，在40 km处测得的径向风速随机误差为8 m/s。径向风速合成为水平风速后，随机误差在38 km处最大为10 m/s左右。该系统白天探测高度为25 km，夜晚探测高度为38 km。与探空数据对比，风速误差均小于10 m/s，其中风速误差在±5 m/s的范围内的数据量约占75.8%，探测的风向误差与探空气球的趋势基本一致，误差范围在10°～20°之间，在15°范围内的数据量约占58.6%。将实测数据与探空数据进行统计分析，结果具有良好的一致性。该系统可以为对流层和平流层大气风场的探测提供数据支撑。

Frequency tracking technology of direct wind lidar and observation of atmospheric wind field in troposphere and stratosphere

In order to continuously detect the tropospheric and stratospheric wind field with high accuracy, a direct wind lidar system is built to detect the tropospheric and stratospheric wind field. Based on the Rayleigh scattering Doppler wind measurement principle of the double edge Fabry-Perot etalon, the system uses a rotary table detection structure, and tracks the frequency drift by means of frequency tracking to ensure the accuracy of wind measurement. The experimental results show that the system has a good detection performance on the tropospheric and stratospheric atmospheric wind field, and the frequency tracking range is ±50 MHz, which can greatly reduce the wind speed error caused by frequency drift. After the stable operation of the system and long-time observation, the random error of radial wind speed measured at 40 km is 8 m/s. After the radial wind speed is combined into horizontal wind speed, the maximum random error at 38 km is about 10 m/s. The detection altitude of the system is 25 km in the daytime and 38 km at night. Compared with the sounding data, the wind speed error is less than 10 m/s, and the data volume within the range of ±5 m/s accounts for about 75.8%. The detected wind direction error is basically consistent with the trend of the sounding balloon, the error range is of 10° to 20° and the data volume within the range of 15° accounts for about 58.6%. The measured data and sounding data are statistically analyzed, and the results have good consistency. The system can provide data support for the detection of tropospheric and stratospheric atmospheric wind fields.