纯转动拉曼激光雷达具有准直性好、时空分辨率高等特点被广泛用于大气温度垂直廓线探测.本文基于干涉滤光片设计分光光路,定量分析了滤光片中心波长和带宽造成的温度测量不确定度.使用比值法简化计算了滤光片对弹性散射信号抑制不足造成的泄露误差.通过不同带宽滤光片标定了系统参数,并分析了系统参数对反演温度时拟合误差的影响.针对滤光片固定时的角度误差,评估了其引入的随机误差.结果表明,系统实际选择的滤光片中心波长和0.5 nm/0.3 nm带宽产生的误差小于1.2 K,抑制比大于6为宜,使用低阶函数产生的拟合误差可以忽略,滤光片固定角度误差应小于0.5°.并基于纯转动拉曼激光雷达方程模拟仿真回波信号并反演温度廓线,分析了温度测量的误差分布,总误差小于1.2 K.
Error analysis of Raman Lidar based on interference filter
Pure rotational Raman Lidar is widely used for detecting vertical atmospheric temperature profiles due to its good collimation and high spatiotemporal resolution.In this paper,the uncertainty of temperature measurement caused by the central wavelength and bandwidth of the interference filter by designing a spectral path based on the interfer-ence filter.The ratio method is used to simplify the calculation of leakage errors caused by insufficient suppression of elastic scattering signals by filters.The system parameters are calibrated by means of different bandwidths,and the im-pact of system parameters on fitting errors during temperature inversion was analyzed.The random error introduced by the fixed angle error when inverting the temperature is analyzed.The results indicate that the error generated by the center wavelength of the filter and the bandwidth of 0.5nm/0.3nm actually selected by the system is less than 1.2K,and a suppression ratio greater than 6 is appropriate.The fitting error generated by the use of lower order functions can be ignored,and the fixed angle error of the filter should be less than 0.5°.And based on the pure rotational Raman Li-dar equation,the simulated echo signal is simulated and the temperature profile is inverted.The error distribution of temperature measurement is analyzed,and the total error is less than 1.2 K.
pure rotational Raman Lidarinterference filtertemperature detectionerror analysis
万方数据
维普
