Development of a Meteorological Lidar for the Analysis of Atmospheric Dynamical Behavior

本研究的目的是研制一种实用的气象激光雷达或激光雷达系统，用于遥测对流层的风、温度和湿度等主要气象参数。该系统可用于分析大气环境问题的基本动力学性质。研制了一种小型、轻量的激光雷达，并进行了实际应用的大气遥感系统测试。(1)人眼安全多功能测风、温、湿激光雷达系统的研制。使用平均功率为0.6 W的355 nm紫外单频激光器，配备直径为20 cm的望远镜和光子计数探测器。对于测风，在直接探测多普勒激光雷达方案中采用了高分辨率的法布里-珀罗标准具滤波器。温度传感基于使用双通道光栅滤波器的旋转拉曼散射方案，并且湿度传感基于使用单个光栅滤波器的振动拉曼散射方案。可以同时测量这些主要气象参数的空间分布。最终测试的风速测量精度为1.5米/秒，在3公里范围内，温度精度为1 K，在1.5公里范围内，湿度为10%，在2公里范围内。(2)LD泵浦单频调Q Nd：YAG激光器小型多普勒激光雷达的研制。研制了一台LD泵浦的紧凑型调Q固体Nd：YAG激光器。采用注入种子和行波腔技术实现单频振荡。采用稳频技术，在10 kHz脉冲重复频率下，平均功率为3 W时，脉冲频率稳定度为0.23MHz。在532 nm处的第二谐波光束用于使用扫描20 cm直径望远镜的风测量。在3 km范围内测风，精度可达0.6m/s。

The purpose of this research is to develop a practical meteorological lidar or laser radar system for remotely measuring major meteorological parameters of wind, temperature and humidity in the troposphere. The system is useful for analyzing fundamental dynamical properties of the atmospheric environmental issues. A compact and light-weight lidar has been developed and tested for practical application as the remote atmospheric sensing system.(1) Development of eye-safe multi-function lidar system for wind, temperature and humidity sensing. The UV single frequency laser at 355 nm with 0.6 W average power was used with a 20-cm diameter telescope and a photon counting detectors. For the wind measurement, a high-resolution filter of the Fabry-Perot etalon was employed in the direct detection Doppler lidar scheme. The temperature sensing is based on the rotational Raman scattering scheme using two-channel grating filters and the humidity is on the vibrational Raman scattering scheme using a single grating filter. The spatial profiles of these major meteorological parameters could be measured simultaneously. The accuracy of the wind measurements was finally tested to be 1.5 m/s at 3 km range, temperature accuracy was 1K at 1.5 km range and humidity was 10% at 2 km range.(2) Development of a compact Doppler lidar with a LD-pumped single-frequency, Q-switched Nd : YAG laser. A LD-pumped compact Q-switched solid-state Nd : YAG laser has been developed. The injection seeding and the traveling wave cavity technique was employed for the single frequency oscillation. Frequency stabilization technique was applied and the pulse frequency stability was 0.23 MHz for 3W average power at 10-kHz pulse repetition frequency. The second harmonic beam at 532 nm was used for the wind measurement using a scanning 20 cm diameter telescope. The wind measurement was possible at the range of 3 km with theaccuracy of 0.6 m/s.