Performance Analysis And Autonomous Navigation Technology For Ad-hoc Microsatellite Constellation

With the rapid development of aerospace science and technology,one single satellite already can’t meet the demand of space missions,and the study of satellite constellations arises.In traditional satellite constellations,different satellites complete their default task collectively with a certain constellation configuration.The cost of traditional constellation constitution is very high,but ad-hoc constellation can solve this problem,and the research of which is getting more and more attention of domestic and foreign scholars.This paper mainly studied the performance of ad-hoc onboard microsat constellations.This kind of constellation has the advantages of more satellite launch opportunities and low constitution cost.However,the other satellites in the constellation need to adapt to the orbit of the main satellite,which causes the irregularity of constellation configuration,and limit the development of ad-hoc satellite constellations.Based on the characteristics of ad-hoc microsat constellations,the main research contents of this paper are as follows:Firstly,the ad-hoc microsat constellation was designed,satellite constellation theory and ad-hoc microsat constellation configuration were introduced.Constellation orbit was analyzed from the respect of orbit parameters and orbit type of its consisting satellites.Typical satellite constellation configuration was analyzed.Then secondary launch and launch opportunity of microsats were analyzed.Secondly,ad-hoc microsatellite constellation characteristic indices are proposed,including the coverage characteristics,aggregation degrees for constellation configuration and health stability,in order to analyze the feasibility of ad hoc microsat constellations.Then,several characteristic indices of ad hoc microsat constellations are compared with those of the traditional constellation,‘‘Walker.’’ Its long-term performance attenuation of ad-hoc microsatellite constellation was also analyzed.Then the autonomous navigation features of ad-hoc microsat constellation is researched.Two traditional autonomous navigation methods for Leo small satellites were introduced,known as magnetic navigation and position information navigation.On the basis of the analysis of their advantages and disadvantages,a new adaptive magnetic navigation method based on position information orbit determination was proposed,and its navigation precision and characteristics were researched.At last,according to the research content in this paper,a ground demonstration platform was set up and then the characteristics and navigation method of ad-hoc microsat constellation were verified.