An autonomous star pattern recognition algorithm using bit match

A novel star pattern recognition algorithm using bit match for star sensor is presented in the paper. At first the entire celestial sphere is divided into n un-overlapped square sub-areas. The number of navigation stars in the sub-area data is saved in the first part of the sub-area data. Every bit 1 refers to a navigation star while every bit 0 not. An 18-bit binary code and an extra 0 are used to the number of successive bit 0s, and 11 are used to a bit 1. These resulted bit numbers are stored in corresponding position in the sub-area data. Let all sub-area data rearrange with the number of navigation stars in ascending order and be stored as the navigation star database. The logical AND operation is used for star pattern recognition. The simulations show that the less time for star pattern recognition and uses less memory for storing navigation star database are used with the algorithm in this paper than those with KMP (Knuth-Morris-Pratt) algorithm.