Storing navigation star database method for star map recognition using character match

Of all current methods for measuring spacecraft attitude, the use of star sensors produces the most accurate measurements, and the key importance is star map recognition in star sensor. An improved method for star image recognition based on KMP (Knuth-Morris-Pratt) is proposed. At first every bit 1 refers to a navigation star while every bit 0 not in the every area of celestial sphere, so an original character string consisting of 0 and 1 is achieved. An integer and an extra 0 are then used to the number of successive character 0s, and 11 is used to a bit 1. These resulted character numbers are stored in corresponding region of navigation star database. The star map recognition is carried out by logic operation. The simulations show that the algorithm reduces the volume of navigation star database and inherits merits of original algorithm.