Strapdown inertial navigation system/celestial navigation system (SINS/CNS) integrated\nnavigation is a fully autonomous and high precision method, which has been widely used to improve\nthe hitting accuracy and quick reaction capability of near-Earth flight vehicles. The installation errors\nbetween SINS and star sensors have been one of the main factors that restrict the actual accuracy of\nSINS/CNS. In this paper, an integration algorithm based on the star vector observations is derived\nconsidering the star sensor installation error. Then, the star sensor installation error is accurately\nestimated based on Kalman Filtering (KF). Meanwhile, a local observability analysis is performed on\nthe rank of observability matrix obtained via linearization observation equation, and the observable\nconditions are presented and validated. The number of star vectors should be greater than or equal\nto 2, and the times of posture adjustment also should be greater than or equal to 2. Simulations\nindicate that the star sensor installation error could be readily observable based on the maneuvering\ncondition; moreover, the attitude errors of SINS are less than 7 arc-seconds. This analysis method and\nconclusion are useful in the ballistic trajectory design of near-Earth flight vehicles.
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