METHOD OF MEASURING POSITION OF SPACE FLYING OBJECT BY CAPTURING STAR AND DISCRIMINATING STAR

摘要

PURPOSE: To judge an attitude error accurately by using a star sensor that is mounted on a space flight object and by selecting at least three target starts and using a number of star positions of a coordinate system that is centered in a solar system with one of them as a guidance. CONSTITUTION: When the field of view 2 corresponding to a maximum attitude error X, Y that can be expected as compared with a sight 1 of a star sensor is prescribed and a space flight object is accurately directed to a desirable, new attitude, three target stars that are expected at known, target positions 3-5 among the field of view 2 are selected, and the star at the position 3 is selected for guidance. Then, when a new attitude is reached, positions 7-12 of a star with the maximum illuminance are determined in a first window 6 that is equivalent to an error 2x, 2y of the expected attitude. Then, a position deviation for the position 3 is corrected, the positions 17, 18, 19, 20 of the brightest star are detected among second windows 15, 16; 21, 22 around target positions 13, 14; 19, 20, its mutual position interval and an interval for positions 7; 8 are judged and are compared with positions 4, 5, and 3, and an attitude error is judged from the difference between the positions 19 and 20 and the positions 4 and 5 of the star.