Strategy Design and Sensor Scheduling for Optical Navigation of Low Earth Orbit Satellites

Space-based optical (SBO) sensor is a special kind of star sensor, which can be used in not only the space-based observation for space objects but also satellite navigation, called optical navigation in this paper. The aim of this paper is to design optical navigation strategy for low earth orbit (LEO) satellites, including the selection of beacon objects, and the sensor scheduling for improving navigation accuracy. The processing and observation geometry of space-based optical observation is illustrated first. Based on the characteristics of the space-based optical observation, the distribution of beacon geosynchronous orbit satellites is designed for optical navigation of LEO satellites. And the sensor scheduling criterion for optical navigation is deduced to analyze the characteristics of optical navigation and schedule the navigation mission. It is found that an efficient way to improve the optical navigation accuracy is to add an additional sensor to track other beacon objects, whose line of sight (LOS) should be perpendicular to the original LOS of the sensor as far as possible. Therefore, global positioning system satellites are used as the supplement of beacon objects. Finally, based on the sensor scheduling criterion, navigation for a LEO satellite with two SBO sensors is scheduled, which obtains more accurate results and converges more rapidly.