利用Fizeau干涉仪进行激光风速测量的原理分析

Analysis of principle of wind velocity measurement with Fizeau interferometer

导出了激光多普勒雷达基于Fizeau干涉仪及CCD探测器进行测风时,每个CCD元最终接收到信号的一般表达式。对系统的参数做了整体优化,得出一组优化参数。在0-3 km高度,得出系统风速误差小于0．16 m／s。对最终的风速反演分别运用最小二乘拟合法和重心法。分析表明最小二乘拟合法只适用于风速较小的情况。详细分析了运用重心法计算风速必然会引起的误差,并提出一种解决方法。修正后,在±30 m／s 风速范围内,该方法产生的误差小于0．25 m／s。

A generalized formulation of signal on each pixel for a wind detection lidar based on Fizeau interferometer and CCD is derived. System parameters is optimized through numerical simulation. System wind error is below 0.16 m/s at the altitude from 0 to 3 kilometers. Least square fitting method and gravity method are used to retrieve wind velocity. The analysis shows that least square fitting method can only be used when the velocity is small. Gravity method is analyzed and the method error is corrected by a new method. After correcting, the error due to the method is below 0.25 m/s at the range of wind velocity from -30 m/s to 30 m/s.