瑞利激光雷达反演中层大气温度算法

瑞利激光雷达是探测中层大气温度的重要设备，具有高时空分辨率且不存在探测盲区的优点.为充分利用激光雷达探测到的原始数据，改进了传统的Chanin-Haunchecorne方法，采用由均匀搜索生成温度初值的方式反演大气温度.位于北京延庆（40.3°N，116.2°E）的瑞利激光雷达具有589nm和532nm两个通道，将589nm通道用于计算，532nm通道作为参考.在150~250K区间等间隔选取多个温度初值，利用589nm通道反演60~70km高度范围内的大气温度廓线和大气密度廓线，利用参考密度廓线选取准确的温度初值，反演得到准确的大气温度廓线.将589nm通道和532nm通道反演的温度廓线相比较，发现二者具有较高的一致性.改进后的方法有效利用了信噪比较差的光信号，使589nm通道的温度探测上限从60km提高到70km. 

Retrieval Algorithm of Middle Atmospheric Temperature Using Rayleigh Lidar

Rayleigh lidar is an important equipment to measure temperature of the mesosphere. It has the capacity for continuous detection with high spatial and temporal resolution. To take full advantage of the original data obtained by Rayleigh lidar, the conventional Chanin-Haunchecorne method is improved. The initial temperatures adopted by the improved algorithm are obtained by uniform search, and then the atmospheric temperature can be inversed. The Rayleigh lidar located in Yanqing, Beijing (40.3°N, 116.2°E) consists of a 589 nm channel and a 532 nm channel. The 589 nm channel is used for calculating atmospheric temperature, and the 532 nm channel is taken as the reference of the former. The initial temperatures are chosen at regular intervals from 150 to 250°K, and the temperature profiles and its corresponding density profiles from 60 km to 70 km altitude is retrieved with the 589 nm channel. The accurate temperature and the corresponding temperature profile can be obtained according to the reference density profile. This reversed temperature profile is compared with that of 532 nm channel. The results show that they have good agreement with each other. This improved algorithm takes full advantage of optical signals with poor signal-to-noise ratio, and improves the upper detection limit of atmospheric temperature with 589 nm channel from 60 km to 70 km. The method is reliable.