提高波前探测精度的高阶矩方法  

Method for improving wavefront detection accuracy based on high moment

作　　者：夏爱利[1,2] 马彩文[1] 

机构地区：[1]中国科学院西安光学精密机械研究所,陕西西安710119 [2]中国科学院研究生院,北京100049

出　　处：《红外与激光工程》2012年第2期472-477,共6页Infrared and Laser Engineering

基　　金：国家863计划(2008AA7080304)

摘　　要：夏克-哈特曼波前传感器测量畸变波前的探测精度主要取决于光斑质心的测量精度。提出了一种提高光斑质心探测精度的新方法,在优化的探测窗口内使用高阶矩方法计算光斑的质心。首先,在整个子孔径内,通过一阶矩方法获得光斑的近似中心,然后以这个近似中心为中心,包含整个光斑,建立一个矩形窗口,并在该窗口内通过高阶矩方法重新计算光斑的质心。通过该改进的方法,在优化的探测窗口外,噪声的影响基本被消除;在优化的探测窗口内,噪声的影响也因为光斑权值比重的增大而削弱。实验结果证明:与传统方法相比,新方法提高了光斑质心测量的精度、重复性和稳定性。The accuracy of the Shack-Hartmann wavefront sensor for measuring the distortion wavefront is mainly dependent upon the measurement accuracy of the centroid of focal spot.An improved centroid measurement approach was presented which calculated the centroid of focal spot more precisely using the higher moment centroid method in an optimized detection window.Firstly,the approximate center of the focal spot by the first moment centroid algorithm in the whole sub-aperture was obtained.Secondly,a rectangular window including the whole focal spot was established,whose center was just the obtained approximate center.Finally,the centroid of focal spot by the higher moment centroid algorithm in the optimized window was calculated again.Based on the improved method,the effects of various noises out of the optimized detection window were almost eliminated.Furthermore,the noise influences in the optimized detection window were also weakened due to the more contributions of the focal spot intensity.The experimental results demonstrate that the precision,repeatability and stability of the centroid measurement of focal spot are more prominent than the results obtained via other commonly centroid methods.

关 键 词：自适应光学 夏克-哈特曼波前传感器 质心计算 高阶矩 

分 类 号：TH703[机械工程—仪器科学与技术]