| Due to the advantages of low-orbit satellites in satellite navigation and communication,the application of low-orbit satellites has been developed rapidly.The current low-orbit satellite measurement and control ground station is seriously inadequate,and it is particularly urgent to optimize the scheduling of the low-orbit satellite measurement and control ground station and make full use of the existing ground station resources.According to national requirements,the National Time Service Center developed and constructed a set of low-orbit satellites telemetry and remote control systems with an antenna diameter of 5 meters.According to the requirements and constraints of the development and construction tasks,this paper studied the optimal strategy for dispatching low-orbit satellite measurement and control ground stations to meet the telemetry,remote control and data transmission tasks of the LEO constellation Research on the site selection of measurement and control ground stations for common low-orbit satellite constellations at home and abroad.Based on the characteristics of the low-orbit satellite constellation measurement and control ground station network that can observe multiple satellites at the same time,this paper proposes two scheduling strategies under different constraints,and Corresponding low-orbit satellite ground station scheduling software was developed,and simulation verification was finally carried out.On this basis,the entire system platform has been tested for joint debugging and satellite-to-ground docking tests to provide a basis for making LEO satellite measurement and control system scheduling strategies.The main research content and results of the thesis are as follows:(1)Research on site selection of LEO satellite measurement and control ground station.Analyzed the selection and layout of the ground station site,the conditions under which the ground station can observe satellites,and the composition of the loworbit satellite constellation involved in this article.A ground station location algorithm based on visible arcs is proposed,which is verified by creating a constellation and setting up a simulation environment.On this basis,the number of visible satellites in the low-orbit satellite constellation is analyzed to provide a reference for the selection of measurement and control ground stations in the subsequent scheduling strategy(2)Research on scheduling of LEO satellite Walker constellation measurement and control ground station.Analyzed the coverage characteristics,and observable arcs of the specific low-orbit satellite constellation,the polar coordinates and observation arcs of the visible seed satellites by different measurement and control ground stations as well as sub-satellite trajectory.The satellite visibility analysis is carried out for a specific low-orbit satellite constellation,two scheduling strategies with different constraints are proposed.There are two constraints: The one is to give priority to observing satellites that are in urgent need of data update;the other is to give priority to satellites with high elevation angles or satellites with long visible arcs.Finally,the two scheduling strategies are analyzed and simulated.At the same time,the advantages and disadvantages of the two schemes are compared in detail.The results show that Compared with strategy 1,strategy 2 has the characteristics of long observation satellite time,low antenna frequency of switching ground stations,and uniform observation satellites.Strategy 2 is more suitable for the actual observation task requirements studied in this paper.(3)Testing and verification of LEO satellite measurement and control ground station.According to the requirements of the scheduling software,the design constraints of the scheduling software and the operation process of the scheduling software are analyzed;the implementation of the low-orbit satellite ground station scheduling software is designed and implemented,including single-antenna measurement and control ground station and multi-antenna measurement and control ground station.Researched of the low-orbit satellite ground station hardware and software transformation plan,Introduced in detail from the transformation purpose,functional requirements,demand analysis,main functions and working methods of the integrated baseband.In accordance with the wired and wireless docking methods,a test satellite satellite-to-ground docking test was carried out.Through the docking test between the satellite and the ground measurement and control system,the correctness of coordination and matching of the on-board S/X-band transponder and the ground station measurement and control can be verified,the correctness and effectiveness of the direct and indirect commands of the remote control can be verified,and the telemetry data can be verified The correctness of the format and parameter processing to verify the main technical indicators of the S/X-band transponder.The dissertation studies and analyzes the low-orbit satellite measurement and control ground station scheduling strategies,developed low-orbit satellite ground station scheduling software and carried out satellite-to-ground docking tests.The 5m low-orbit telemetry and remote control system has been built to support the development and construction of the system. |
