Research Of Star Map Simulation And Identification Algorithm Based On Star Sensor

Star sensor is a kind of device that used for astronomy navigation measurement. Due to the advantages such as the superior measurement accuracy, no accumulated error and good autonomy etc., star sensor is extensively applied to the space vehicles and becomes a much concerned subject in the field of aviation, space flight and military. As the core of star senor,star map identification is the precondition of the accuracy of the spacecraft's gesture and position. Star map identification is to compare and match the stars in the current field of vision with the navigational stars in the storage of navigational database for the purpose of achieving the identification of stars in the current field of vision. Therefore, the accuracy of star map identification technology is always important to this study. For the star map identification algorithms, star charts' generation that can imitate the star image's photo taken by star senor given the star sensor posture or optical axis is the precondition of this study. It provides base for the further Star pattern identification algorithms. This paper mainly develops the study in the star map imitation and star map identification.First, this paper introduced the structure and work process of star sensor and analysed the principle of the star pattern identification and the navigation method using star sensor. We chose the appropriate observation star catalogue and the navigation star catalogue from the basic star catalogue according to the principle of star pattern imitation and identification as well as the requirement of the topic, which made preparation for star pattern imitation and star pattern identification.Second, we used the computer simulation technology to simulate star in the ground according to star sensor's imaging principle and star's imaging model and added the corresponding white Gaussian noise. Simultaneously, we tested and verified the effectiveness of star pattern imitation through adopting the characteristics of the angular distance between star and transmission projection's principle .The simulation results indicated that the proposed star pattern imitation is accurate and reliable.Finally, we studied the star map identification technology. This paper mainly studied the grid identification algorithm due to the obvious advantages compared to others. We introduced the concept of Metric function, proposed an improved grid identification algorithm and simulated this algorithm for the traditional grid identification algorithm was unable to reflect pattern vector acquaintance degree in characteristic space. Simulation results show the developed algorithm is better than the former algorithm in both robustness and accuracy.