Non-Dimensional Star Identification for Un-Calibrated Star Cameras
Additional Document Info
Star identification is the most critical and important process for any star sensor. The main purpose of the Star-ID is to identify the observed/measured stars with the corresponding cataloged stars. The precision of the observed star directions highly depend on the accuracy of the star camera parameters, mainly the focal length f, and the optical axis offsets (x 0, y 0). When these parameters are not accurate or when the camera is not well calibrated, the proposed Non-Dimensional Star-ID method becomes very suitable, because it does not require accurate knowledge of these parameters. The Non-Dimensional Star-ID method represent a unique tool to identify the stars of un-calibrated or inaccurate parameters cameras. The basic idea derives the identification process from some observed parameters (the focal plane angles) which are, at first order, independent from both the focal length and the optical axis offsets. The adoption of the k-vector range search technique, makes this method very fast. Moreover, it is easy to implement, accurate, and, for typical star tracker design parameters, it shows star-ID failing probability less than 10 -11.