Simulation analysis and research on key technology for a full-time-running stellar refraction autonomous navigation

Abstract

Navigation based on stellar refraction refers to a method that uses large visual field star sensor to detect several stars refracted and not refracted by earth atmosphere, and then finishes autonomous navigation based on star map recognition, with merits such as simple system structure, low cost and high navigation accuracy. However, in order to achieve full-time-running high accuracy, three key technologies, namely strong background star map acquisition, refracted star extraction under strong background and atmospheric model should be solved for such method. By constructing observation policy model and detection limit model under the strong background, this paper realizes high SNR (Signal to Noise Ratio) star map acquisition under strong background through anti-blooming function of detector, and carries out theoretical analysis and outfield test; realizes recognition of dim refracted star and high-accuracy centroid positioning of refracted star under strong background via specific star pick-up algorithm, and performs outfield test on it; studies high-accuracy atmospheric model optimization method and proposes an applicable stellar refraction atmospheric model based on atmospheric refractivity change and identical with stellar refraction rule. Finally, on the basis of key technological solution study, it constructs stellar refraction navigation simulation system based on stellar refraction navigation realization approach and analyzes the influences of key error sources on navigation accuracy through simulation, so as to obtain the result that the accuracy of full-time-running navigation based on stellar refraction is superior to 1.2 km.