高精度星敏感器星像能量分布模型研究

Mathematical Model Research of Star Image Energy Distribution of Star Tracker

为了得到一种有效的高精度星点提取算法,直接将高斯分布作为星敏感器星像能量分布的做法已经不能满足实现甚高精度星敏感器的要求,因此必须研究实际星敏感器星像能量分布模型。使用了偏正态分布来描述高精度星敏感器星像能量分布,设计了仿真实验和测量实验来对比两种模型的拟合效果。仿真实验和测量实验结果均证明,偏正态分布更加接近星敏感器星像分布,研究成果可以应用于星敏感器精密视场校正算法的研究。

In order to obtain an accurate centroiding algorithm, it is inappropriate to directly regard star image energy distribution as the Gaussian distribution because of the upgrading demand of ultra- high precision star tracker. It is urgent to study the actual star image energy distribution. This paper studies the theory of mathematical statistics about discrete data model deviating from the normal distribution. The skew Gaussian distribution is proposed to describe star image energy distribution of high precision star tracker. Both simulation and measuring experiments prove that the actual distribution of the star image get closer to the skew Gaussian distribution. The results can be used to guide the research of the precise correction algorithm of the star tracker which can correct the coordinates of the centroid.