哈特曼技术在序列光斑检测中的应用  

Application of Hartmann technique in sequence spot detection

作　　者：母一宁[1] 刘泉[1] 于林韬[1] 李平[1] 

机构地区：[1]长春理工大学,吉林长春130022

出　　处：《光学精密工程》2011年第9期2197-2204,共8页Optics and Precision Engineering

基　　金：国家863高技术研究发展计划资助项目(No.2003AA712014)

摘　　要：为了提高水平链路大气无线激光通信中的对准精度,降低强湍流对激光通信的影响,对系统结构进行了改进并研究了光斑检测对准算法。首先,根据哈特曼-夏克传感器对波前畸变局部的实时探测结果,计算局部畸变的变化量,从而实时确定局部截止频率-局部判决阈值Tn。接着,采用统计序列均方误差获取序列采样信息M(Xi,Yi),并根据局部阈值判决确定信标序列采样空间(Xi,Yi)。最后,遵循最小二乘原则进行圆心拟合,使序列均方误差达到最小,并从信息论的角度出发,分析了基于序列信息圆心拟合光斑检测法的优缺点。实验结果表明,在湍流中该方法的检测精度优于4μrad,比传统质心算法的检测精度高1倍,满足了大气无线激光对准的基本要求,较好地回避了湍流引入噪声过大这一难题。The structure of the system is aimed at improving the spot detection algorithm,in order to improve the level of an atmospheric wireless laser communication link alignment accuracy by reducing the impact of turbulence on laser communication.First,we calculate the changes in the local distortion to determine the real-time local decision threshold Tn by a Hartmann-Shack wave-front sensor on the local distortion of the results of real-time detection.We then obtain the sequence of Mean Square Error（MSE） from the sampling information M（Xi,Yi） by a statistical series.At the same time,we can determine the sampling space（Xi,Yi）of the beacon based on the local threshold.Second,we use the center of a circle for fitting to make the MSE a minimum by following the method of least squares.We also analyse the advantages and disadvantages of the method with center-fitting of spot detection based on the sequence information,from the perspective of information theory.The results show that the detection accuracy is better than 4 μrad in the turbulence and more than twice the traditional centroid algorithm.The method avoids a problem with the introduction of strong turbulence noise.It basically meet the requirements of Air-Wireless-Laser alignment.

关 键 词：序列信息 圆心拟合 波前畸变 最小均方误差 哈特曼技术 

分 类 号：TN929.1[电子电信—通信与信息系统]