Research on the Uplink Task Scheduling Strategy of Satellite Navigation System

摘要

In order to keep the service availability, continuity, and accuracy of satellite navigation system, the navigation data of the navigation constellation should be updated periodically. The navigation data are generated in the ground master control station, and are uploaded to the satellites by ground uplink facilities. Generally, in full operational phase, there will be about 30 satellites in space and several uplink facilities on ground. In order upload the navigation data timely to the satellites, ground facilities should be assigned to contact with the satellites. Due to the number of satellites and facilities, and the complex constraints in the uplink process, how to arrange the contact process is a complex problem. A mix-integer model is devised in this paper considering technological constraints in uplink process and different objective functions. Due to the complexity of the model, a two-phase algorithm based on rules is devised to solve the model. A set of scenarios for computational experience are devised consulting COMPASS of China, GPS and Galileo Satellite Navigation Systems. Our method is proved effective to the uplink task schedule process. Several factors that influence the completion of the uplink tasks are analyzed through the computational experience. The methods of this paper will be useful to the operations management of the Chinese COMPASS Satellite and forthcoming European GALILEO Navigation Systems.