Researches On Assignment Of Inter-Satellite Links For Navigation Satellites

A trend of Global Navigation Satellite System (GNSS) is developing inter-satellite links (ISLs), because that navigation constellation can improve performance by the network which consists of inter-satellite links. Besides, the network of ISLs can make up for a lack of observations which results from the limit of ground station outside China. ISLs assignment is a prerequisite to the communication of the ISLs network. At present most researches of ISLs assignment are about satellite with wide beam antenna, while there is few researches about satellite with spot beam antenna. Therefore, this paper aiming at Chinese BeiDou navigation constellation, study the ISLs assignment under the conditions of satellite while spot beam antenna. The main results achieved in this dissertation are summarized as follows.1) The analysis of working patterns and topology of navigation constellation. The paper analyses the frequency and type of satellite antenna, discusses the multiple access of the GNSS, and provides a method of dealing with navigation constellation topology.2) The study of performance and constraint conditions of ISLs network. Under the requirement of ISLs network, this paper comes up with standards of performance of ISLs network, analyses the constraint conditions about building ISLs, and calculates the visibility of navigation constellation.3) The study of ISLs assignment. Considering the working patterns and visibility of ISLs network, this paper comes up with a ISLs assignment, which takes account of both measures and communication of ISLs network. Furthermore, in order to verify the rationality and feasibility of the ISLs assignment, a simulation experiment was carried out.The simulation results indicate that, the ISLs assignment guarantees that the PDOP is less than 3; while the time delay from satellites inside China to the others is less than 6 seconds. Therefore, It is reasonable and feasible, satisfies the needs of the experiment project and has certain practical value and application prospect.