Latitude-longitude preserved quasi-uniform spherical partitioning for efficient star catalog retrieval

Aiming at the deficiencies of traditional latitude/longitude-based methods and uniform spherical subdivision methods, this paper constructs a quasi-uniform guide star catalog division method related to latitude and longitude information. This method first divides the triangular grid on the two-dimensional latitude and longitude grid, and then maps the division result to the three-dimensional surface of the celestial sphere. The method takes into account the uniformity of the star catalog and the correlation of the latitude and longitude of the star map data. The analysis shows that after adopting the quasi-uniform guide star catalog division, combined with the longitude and latitude-related coding methods in this paper, the query and application efficiency of the navigation star catalog has been improved. Tests based on Gaia DR3 catalog data show that among 60,000 navigation stars with magnitudes <6.0, the average retrieval latency of the 512-subblock database constructed by this method is 1.2 ms (a 53% reduction compared to the latitude-longitude partitioning method).