ADAPTIVE STAR CENTROIDING METHOD IN STAR SENSOR BASED

摘要

A method for finding centroid of an adaptive star in a star sensor is provided to improve accuracy and speed in star pattern recognition and pose decision by previously removing unusual stars in a cluster forming process. A method for finding centroid of an adaptive star in a star sensor includes the steps of: compensating dark current in a star image photographed by a CCD(Charge-Coupled Device) in a star sensor; measuring average brightness of a background image corresponding to an outer space from a selected scan window to separate the star image displayed on the CCD from the background image corresponding to the outer space; selecting the minimum effective brightness level from the average brightness of the background image of the outer space; detecting valid pixels above the minimum effective brightness level; forming a cluster with valid pixels above the minimum effective brightness level; removing stars with unusual shape in the cluster; and calculating centroid of the clustered star with a centroid method.