Celestial navigation by observing the sun is a hot issue in recent years, and how to improve the positioning precision is a concerned problem to researchers in the world. The positioning principal by observing the height of the sun is adopted in this paper, and the gray centroid algorithm to extracting the sun's center is introduced. Processing the practical data, the CCD observing precision of the sun is analyzed. By simulative calculation, impact of the sun's position, observing precision, tracking time and CCD observing period on positioning precision is analyzed quantitatively. Then, the best observing scheme is put forward, which means that the best observing time is in transit around, and the tracking time should be as long as possible, and CCD sampling rate should be as high as possible. Practical observing data shows that positioning precision can be improved from 15" to 5" when tracking time extends from 30 to 90 min.
展开▼
