Levenberg-Marquardt算法在测风激光雷达中的应用

分析了直接探测测风激光雷达中的Fabry-Perot标准具透过率的非线性理论模型。根据实验测量数据，利用Levenberg-Marquardt算法对理论模型进行参数优化估值，获得测量数据的最佳拟合曲线。数值计算表明，pseudo-Voigt函数能快速且很好地近似计算Voigt线形。对于Fabry-Perot标准具的宽带光透过率频谱响应曲线，可以采用Voigt函数拟合,也可以采用pseudo-Voigt函数拟合；当透过率频谱响应曲线用于风速反演时，若采用pseudo-Voigt函数拟合会造成低于1 m/s的测速偏差，因此必须采用Voigt函数拟合。

Application of Levenberg-Marquardt algorithm in the wind lidar

Nonlinear theoretical models of the Fabry-Perot etalon′s transmittance in the direct detection wind lidar are analyzed. With experimental datum, the models parameters are optimized with Levenberg-Marquardt algorithm, and for the best fitting curve of Fabry-Perot etalon transmittance. By numerical calculation, it is indicated that pseudo-Voigt function can approach approximated the Voigt profile well and quickly. Both Voigt function and pseudo-Voigt function can be used for fitting the responsive curve of Fabry-Perot etalon transmittance with pulsed laser. But Voigt function should be employed for fitting the Fabry-Perot etalon transmittance curve for the recovery wind velocity, if pseudo-Voigt function is employed, there will be a velocity error which is less than 1 m/s.