基于菲索干涉仪多普勒激光雷达的风速及后向散射系数反演

Inversion of Wind and Backscatter Coefficients from a Fizeau Interferometer Based Doppler Lidar

提出在基于Fizeau干涉仪的测风激光雷达的系统中,对回波信号利用非线性最小二乘法可同时反演得到风速和后向散射系数比。该方法无需确切知道实际的系统参数大小如望远镜视场角、几何重叠因子等。用Monte-Carlo方法模拟了回波信号并利用该方法进行了风速和后向散射系数比的反演,结果表明:在3km高度处,由信号的散粒噪声引起的相对测量误差小于0.2%。同时,又给出了在不同信噪比情况下,反演精度随之变化的关系图。当峰值信号光子数高于500时,风速和后向散射比误差很小。

A nonlinear least-squares inversion method is then described that permits the recovery of wind velocity and aerosol-molecular ratio without requiring system parameters such as the telescope field of view and laser beam overlap function. The signals simulated by Monte-Carlo technique are used to retrieve the wind velocity and aerosol-molecular ratio. The results show that the relative measure error is below 0.2% at altitude of 3 kilometers. Simultaneity, inversion accuracy is given under various signal-noise levels. For a peak signal level of more than about 500 counts, the measure error in the fitted parameters is reasonable.