A FAST AUTONOMOUS STAR-ACQUISITION ALGORITHM FOR SPACECRAFT

An algorithm capable of real-time autonomous star recognition from lar ge star catalogues, with minimal storage requirements, is described. T he algorithm is based on a locally optimised binary tree-search techni que that systematically divides the search space until a small set of stars is left in the identification set. Simulation results are presen ted to verify that the search algorithm can always identify the correc t star, even in the presence of bounded measurement noise, not necessa rily uniquely, but at least to within a small set of possibilities. Im plementing the algorithm in Matlab on a 486DX25 PC, a search time of l ess than 100ms for a 20074-entry star catalogue is demonstrated.