A new star pattern identification algorithm is proposed based on the fact that any triangle is determined by its two sides and circumcircle radius which can partially describe the structural feature of the triangle.Navigation star database is constructed using this algorithm

the capacity of the navigation star database is reduced by using characteristic triangles as the matching template.The characteristic raduis is used for indexing and carried on a ascending rank to improve the searching efficiency in the process of star pattern identification

the matching scope of the argument is narrowed and the matching rate of argument is improved by the matching of the characteristics raduis

and the identification rate is effectively improved by the combination of multi-triangles.The verification process is introduced to confirm the identification results.Simulation results show that the proposed algorithm has better robustness for position error

when the Gauss noise of position error is two pixels

the identification rate is larger than 97.42 % and the average identification time is 31.41 ms.