Improved autonomous star identification algorithm

• Published in: Chinese physics B Vol. 24; no. 6; pp. 321 - 327
• Main Author: 罗丽燕 许录平 张华 孙景荣
• Format: Journal Article
• Language: English
• Published: 01.06.2015
• Subjects: Algorithms; Autonomous; LPT算法; Mathematical analysis; Navigation; Robustness; Stars; Vectors (mathematics); 主星; 对数极坐标变换; 旋转不变性; 特征向量; 特征数据库; 识别时间; 识别算法
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/24/6/064202

The log-polar transform （LPT） is introduced into the star identification because of its rotation invariance. An improved autonomous star identification algorithm is proposed in this paper to avoid the circular shift of the feature vector and to reduce the time consumed in the star identification algorithm using LPT. In the proposed algorithm, the star pattern of the same navigation star remains unchanged when the stellar image is rotated, which makes it able to reduce the star identification time. The logarithmic values of the plane distances between the navigation and its neighbor stars are adopted to structure the feature vector of the navigation star, which enhances the robustness of star identification. In addition, some efforts are made to make it able to find the identification result with fewer comparisons, instead of searching the whole feature database. The simulation results demonstrate that the proposed algorithm can effectively acceldrate the star identification. Moreover, the recognition rate and robustness by the proposed algorithm are better than those by the LPT algorithm and the modified grid algorithm.