为了提高星地光通信中捕获跟踪瞄准系统的目标探测精度,需要对面阵探测器上信标光斑位置探测的随机误差进行高精度分析评估。基于影响光斑探测的多种随机因素,建立了不依赖于目标信号点扩散函数的质心定位噪声等效角(NEA)模型,并仿真了不同因素对NEA的影响。结果显示,不同目标信号点扩散函数下的NEA的变化趋势相似: 随噪声的增大而增大,随信号强度的增大而减小,随光斑半径的增大而增大。不同目标信号点扩散函数下所计算出的NEA数值不同,最大差异小于30 %。研究结论为目标位置探测的随机误差提供了测量方法和理论分析依据,对远距离星地光通信链路的建立与保持具有重要意义。

In order to improve the target's detection accuracy of the acquisition, tracking, and pointing system used in satellite-to-ground optical communications, the analysis and evaluation with high precision are needed for the random errors influencing the position determination of the beacon spots on the flat-panel detector. Considering a variety of random factors influencing spot detection, a noise equivalent angle (NEA) model for the centroid localization which is not dependent on the point spread function of target signals is established and the influences of different factors on the NEA are simulated. The results show that the change trend of NEA value under each point spread function of target signals is similar. It increases with the increase of noise, decreases with the increase of signal intensity, and increases with the increase of spot radius. The NEA values calculated under different point spread functions of target signals are different, but the maximum difference is less than 30%. The research result provides a new measurement method and a theoretical analysis basis of random errors existing in target position detection, and is of great significance to the establishment and maintenance of long-distance satellite-to-ground optical communication links.