Lunar Satellite Orbit Measurement Based on Visual/Radio Fusion

A set of new orbit Measurement method was proposed based on the integration of high-resolution lunar surface imaging and ground-based radio measurement. Through the method, the advantage of stable tracking by radio measurements and the advantage of short-range measurement by onboard camera are expect to be fully integrated. The basic idea of the method is as following. First, combined with orbit constraints of a lunar high resolution imaging satellite, relying on optical imaging information and available reference images on the lunar surface, and based on the visual related theory of multi-view geometry and photogrammetry, the accurate location information of the satellite platform in a moment was calculated. Then, the location information was fused reasonably with satellite speed, range and angle by ground radio measurements. Thereby, a more flexible lunar orbiter orbit determination method than the existing methods was established. Currently, based on real data of “Chang’E II” satellite, visual/radio fusion-based orbit determination model were studied. Transfer relationship of the position and attitude between the satellite and imaging points on lunar surface was derived. Typical aspects of information fusion-based orbit determination were analyzed. Preliminary experimental results verify the feasibility of the proposed method. After parameter calibration, the partial positioning accuracy of “Chang’E II” is better than 100 m, variance limits at 30 m.