A positioning and navigation algorithm based on threshold design

Accelerometer errors are unobservable in non-maneuvering flight, which will lead to low navigation accuracy. Based on the threshold determination strategy, this paper proposes an improved navigation algorithm with high accuracy. The relationship and transformation among different coordinate systems are obtained, and a position information acquisition method is proposed by merely utilizing star sensors and accelerometers. This paper also analyzes the main factors affecting navigation accuracy. Simulation results have demonstrated that the accelerometer threshold strategy is effective, and the positioning accuracy is only determined by star sensors and accelerometers while not influenced by the platform initial errors. The positioning error is within 100 meters with medium-level navigational devices, which is half of that for traditional inertial/celestial navigation algorithm.