Research On Chain-built Strategy Of Satellite Navigation Network Based On Facility Links

It is an important research area of satellite navigation system to realize autonomous navigation and improve the ability of autonomous survival of satellite.The inter-satellite links technology is one of the key technologies to improve the accuracy of satellite navigation system and the ability of autonomous survival.With the inter-satellite links,satellite navigation system could keep working normally even if it lost the support of the ground station.So the inter-satellite links technology attracts more and more attention now.With the inter-satellite links,satellite navigation system can complete inter-satellite ranging and communication.As a kind of inter-satellite links,facility links have a great superiority on the inter-satellite ranging.In order to guarantee the quality of communication between satellites,it needs a further research on chain-built strategy of satellite navigation network based on facility links.The main contents of this paper are shown as follows.Firstly,we do a research on the basic theory about the problem of facility chain-built.We analyse the visibility condition between satellites with considering the constraints of the earth shelter and limited azimuth angle.We put the satellite into a constellation as a consideration and get the minimum number of visibility satellite of the constellation.We also reference some ideas about Finite State Aotomaton to deal with the topology of satellite network and divide the cycle time of the system into many pieces.It is the basic work of further research.As well,we also analys the operational principle and working process of facility links.Secondly,we make a further analysis about problem of facility chain-built.We propose the problem's optimization objective,constraint condition,input variables and output variables and express them with formal description.In order to measure the performance of the network information communication,we propose an index called cost of information transmission delay.At the same time,we come up with two methods to calculate it with reachability matrix and directed complete graph building.Then,we do a research on strategy of facility chain-built and propose two stetegies.One of it is based on simulated annealing to search the optimal solution by variation and renovation.We transfer the link assignment problem into appointment problem to generate the initial solution.As the limitation of computing resources on the satellite,we mend the renovation process and by increasing the number of initial solutions to increase the probability of getting to the optimal solution.The other strategy is based on the feature of satellite network topology.It is easy to compute and is convenient for the satellite.Finally,we do some simulation experiment and analysis.We test and verify the strategy proposed in this paper and we arrave at some valuable conclusions.It turns out to be that the two strategies we proposed have some theoretical and realistic meaning.