Abstract: In order to further improve star positioning precision of star sensor, the pixel error source and formation mechanism are analyzed.Based on multiframe correlation filtering, a correction method of nonuniformity pixel error applied to star sensor is proposed. Star centroiding field and local correction field are determined according to the position of star. The information of currentframe star map and formerframe local correction filed are utilized to predict the currentframe local correction field. Corrected star centroiding filed can be obtained by difference method. Experimental results show that nonuniformity noise can be predicted and positioning accuracy is improved better by proposed method, which is also with good robustness.

Key words: star sensor, nonuniformity error, multiframe filtering, star positioning