基于多步长最大信息熵的空间目标质心定位

摘要

The centroid accuracy of star tracker is the base of other accuracies .It's the base of celestial navigation ,star map identification ,orbit positioning and so on ,which is required to reach arc second scale .This paper analyses the main fac‐tors affecting the positioning accuracy of target centroid and the method for star target centroids based on multi‐step maxi‐mum information entropy is proposed .This method uses the linear superposition to narrow the centroid area ,using the sym‐metry of the stellar energy distribution to get the difference at centroid position and obtain the centroid ,then the validation comparison of simulated star images .Experiments show that the positioning accuracy of the method up to 0 .01 pixel ,has good effect to calculate the centroid of low SNR conditions .%高精度星敏感器星点光斑的质心定位精度是星敏感器整体定位精度的基础，是天文导航、星图识别、轨道精确定位等技术的基础，常需要达到角秒级和亚像素的标准。论文分析了影响定位精度的主要因素，并研究了 CCD 观测图像亚像素的高精度质心定位方法，并分析了恒星成像时能量的分布，提出基于多步长最大信息熵的质心定位方法，该方法使用线性叠加缩小质心区域，利用恒星能量分布的对称性，求取信息熵最大时的质心位置，并采用模拟星图验证比较。实验表明，该方法定位精度可达0．01pixel ，对低信噪比条件下的质心计算具有较好的效果。