给出了用发光二极管测量闪烁和流速光源远场理想特性的表达式.波前扭曲可以分解成波前倾斜和曲率改变两部分来处理.波前倾斜和离轴接收信号的情况相当,对测量结果影响不大.当波前曲率半径不等于到光源的距离时,对流速和闪烁强度测量都会带来不能忽略的误差,路径加权函数的对称特性也会改变.最后给出的流速测量的实验结果和理论计算是一致的.
The expression of ideal far field feature of LED (Light Emission Diode) source for the measurements of scintillation intensity and flow velocity was derived. Wave front destortion of LED source can be divided into incline and curvature variance of wave front. The incline of wave front is equivalent with the receivers at abaxial location,and the measurement errors of scintillation intensity and flow velocity can be ignored. But the measurement errors of scintillation intensity and flow velocity can not be ignored when the curvature radius of wave front influenced by beam twisted does not equal to the distance to the light source. At the same time,the symmetry of path weighting function would be changed. The experiment was taken and the measurement results agree with the theoretical calculation well.