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A celestial positioning method based on modified triangle algorithm and star centroiding with local PSF estimation
DOI:10.1016/j.measurement.2025.117140.png)
Abstract
En 中文
Celestial positioning is a widely adopted high-precision positioning method in observation missions. Its accuracy relies fundamentally on high-precision star centroiding and an efficient star identification algorithm. (1) In star centroiding, a centroid correction using local point spread function (PSF) estimation is employed. Enhancements are also made to the coarse positioning procedure and the weighting function to improve overall precision. (2) In star identification, a modified algorithm is proposed to address the complexity of constructing a lookup table and the issue of excessive redundant results in the traditional triangle algorithm. This approach introduces four feature stars and a segmented rapid traversal algorithm for star pair catalog, significantly enhancing algorithm efficiency and applicability. A theoretical reference star scatter plot is also constructed and compared with the star image, using evaluation metrics such as the number of overlapping points and the average error. Experiments based on wide-field telescope imaging data show that this celestial positioning method achieves a 46.5% increase in matching rate, and reduces redundant matches by 98.6% compared to the previous approach during the star identification phase. The proposed method achieves an average error in star positioning results of less than 0.90 '', and the total error is significantly reduced compared to other baseline methods, with a maximum reduction of 35.0%.
Keywords:
Celestial positioning
Star identification
Modified triangle algorithm
Star centroiding
Local PSF estimation
Journal
IF:
5.6
Papers:
2.0W
Citations:
5.4W

