摘要
分析了利用Shack-Hartmann波前传感器子孔径对之间光强信号的时间延迟交叉相关函数,进行光传播路径上横向平均风速测最的基本原理,给出了横向平均风速的计算公式,并进行了水平1 km湍流大气实验测量。实验结果如下:不同子孔径对同时测量的横向风速相关系数达0.988;将多对子孔径对测量的结果取平均,与接收端附近布置的风速计测量的横向风进行了对比,发现两系统的测量结果在随时间的变化趋势上具有较好的一致性,两次实验拟合的相关系数分别为0.848和0.820,标准偏差分别为0.372和0.376。以上结果表明,将Shack-Hartmann波前传感器用于横向平均风速的测量是可行的,拓展了该传感器的使用功能。
By measuring time lagged cross correlation function with a pair of sub-apertures of Shack-Hartmann wavefront sensor, the path-averaged transverse wind speed and wind direction can be found directly from the slope of this function with no time delay. Experiential formula to calculate the path-averaged wind speed is deduced. And the experiment on it in 1000 m horizontal propagating path was carried out for the first time by use of a Shack - Hartmann wave-front sensor. Some results were found. Firstly, the correlation coefficients of wind speed reach 0.988 from different pairs of sub-apertures; secondly, the results from different pairs of sub-apertures were averaged, and the variation trend was in accord with gained from an anemometer placed in the 15-m tower. The correlation coefficients of two typical experiments are 0. 848 and 0. 820 respectively. All the experimental results indicate that measuring path-averaged transverse wind speed by Shack-Hartmann wave-front sensor is feasible, which extends the function of this sensor.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2009年第2期303-307,共5页
Acta Optica Sinica
基金
中国科学院创新基金(CXJJ-249)资助课题
