天文导航中星点的定位精度至关重要,会影响天文导航的精度。传统的基于线性插值的星图分辨率提高方法是直接利用线性关系来计算插入的灰度值,但忽略了原函数自身的变化特征。针对星点的成像特征,提出了一种基于改进线性插值的星点定位方法。首先建立星点的成像模型并推导出一维模型,求取二阶导数以获得凹凸分界点,然后给出改进线性插值的权值因子的计算方法,进而完成星点的定位。仿真结果表明,与传统方法相比,所提方法的平均偏离误差降低了15.4%,能够有效地提取星点中心。

The positioning accuracy of star points is essential in astronomical navigation, which affects the accuracy of astronomical navigation. The traditional method for improving the resolution of a star map based on linear interpolation directly uses the linear relationship to calculate the gray value of insertion, however it ignores the own change characteristics of original functions. In view of the imaging characteristics of star points, a method of star location is proposed based on improved linear interpolation. First, we establish the imaging model of star points, deduce the one-dimensional model, and obtain the concave convex boundary point by calculating the second-order derivative. Then we give the method for calculating the weighting factor of improved linear interpolation, and finally the location of star points is realized. The simulation results show that, compared with the traditional method, the proposed method has an average deviation error reduced by 15.4%, and it can effectively extract the center of star points.