Method of improving real-time of star sensor based on predicting and tracking star catalog

To improve the efficiency of star sensor during the transition from star tracking mode to full-sky star identification mode, a novel method of synchronously predicting and tracking guidance star sub-catalog while in star tracking mode was proposed. The work mode transition was always prepared, therefore the real-time property of star sensor was improved. The overall catalog architecture which was hierarchical storage and sequentially mapping' was designed. Based on this architecture, guidance stars were homogenized, the overlapped sub-catalogs were generated, and fast searching and management of data were realized. The attitude of star sensor at next time was predicted by using the attitude data of air vehicle. The address of sub-catalog was predicted and tracked by the built index relationship between bore sight of star sensor and addresses of sub-catalogs. Once star tracking failed, full-sky star identification implemented in four redundant sub-catalogs, therefore the process of star identification was simplified, and the efficiency was improved. Experimental results show that the designed star catalog is more scientific and reasonable. The proposed method has strong robustness. The real-time property in work mode transition of star sensor at highly dynamic condition can be effectively improved.