大气压力探测用激光雷达的对称性分析

为了实现世界气象组织对大气压力廓线和地表压力特别高的探测精度，需要消除湍流对距离分辨差分吸收激光雷达和路径积分差分吸收激光雷达的干扰。探测/参考双波束被转换成左旋圆偏振光和右旋圆偏振光后被同时发射出去，经大气后的回波再被1/4波片、偏振分束片以及两个F-P标准具重新分离而被检测到。差分吸收激光雷达的除法、对数和积分运算由模拟电路进行对称的实时处理，这样有利于减小由双通道差异化带来的误差。差分吸收激光雷达的探测波束脉冲与参考波束脉冲同路径传输、同时发射、同时接收，可抵消大气随机运动等因素对系统的共模干扰。模拟研究结果表明，差分吸收激光雷达采取严格的对称性安排，是一个可提高系统探测精度的十分有益的举措。

Analysis of Symmetry of Lidar for Atmospheric Pressure Detection

To realize the particularly high detection accuracy proposed by World Meteorological Organization (WMO) for atmospheric pressure profile and surface pressure, the interference of turbulence with range-resolved differential absorption lidars and integrated path differential absorption lidars should be removed. A detection beam and a reference beam are converted into a left-handed rotation polarization light beam and a right-handed rotation polarization light beam respectively. Then, both beams are emitted synchronously. The echoes transmitted by atmosphere are separated again by a 1/4 wave plate, a polarized light splitter and two F-P etalons and then are detected. To reduce the error due to the difference between two channels, the division, logarithm and integral operation are processed symmetrically by an analog circuit in real time. The same path transmission, synchronous emission and synchronous receiving of both the detection beam pulse of a differential absorption lidar and the reference beam pulse can cancel the common-mode interference of the factors such as atmospheric random motion with the system. The simulation research results show that the symmetric arrangement of a differential absorption lidar is a most beneficial measure for improving its detection accuracy.