The Application Of Satellite Orbit Theory In Maintaining The Space Object Catalog

It has been over50years since the beginning of the space object cataloging (SOC) when it only served for military purpose. As the development of space science, nowadays the SOC serves for many peacetime uses. As the increase of the number of space debris, the application of the SOC has become critical to avoid the collision of space debris in order to guarantee the success of space mission and mitigate the increase of the number of space debris.The article is about the application of satellite orbit theory in maintaining the space object catalogue, which covers main aspects of cataloging, including orbit propagation, precise orbit determination (POD), correlation and the cataloging of new objects.The first part of the article is an introduction of the cataloging system, in order to show the flow of data process and the main methods of the SOC. The main area of the research in maintaining the space object catalogue is also introduced in this part of the article.Chapter1is an in-depth research on the SGP4/SDP4model which is used for the propagation of TLE data. It is important to analyze the propagation accuracy of TLE since it is the largest and most widely used space object catalog in the world. The details of formulating the analytical propagation model are described in this chapter. The method of von Zeipel is introduced to formulate the conservative part of SGP4model which is used for the propagation of LEO objects. Some modification is also introduced in order to formulate the non-conservative part of the model caused by atmosphere perturbation. For the SDP4model which is usually used for the propagation of MEO and GEO objects, the formulation of the third body gravitation and the resonance effect caused tesseral harmonic part of the Earth gravity is also analyzed in this chapter.Chapter2is about the theory and application of POD. In the first part, the POD theory is introduced, including the linearization of the nonlinear system, the formulation of computing the observation and state transition matrix, and the method of optima estimation. In the second part, two methods of ephemeris computation are introduced, including the numerical integration and analytical method. The method of quasi-analytical average is introduced to formulate the analytical model. In order to show the effect of compensation terms induced by the approximation of integrated functions when using the quasi-analytical average method, the propagation model of GEO objects is formulated under the influence of J2and J22 terms. The last part of this chapter is about the application of POD theory based on the observations of Shenzhou-6. Both numerical and analytical methods are applied in the POD and GPS data is introduced to show the accuracy of the results.Chapter3is about the research of new object cataloging. New object cataloging can be considered as the main approach to increase the number of catalog object. The new object cataloging can be realized by processing the uncorrelated observation data, which includes3parts. The first part is about the initial orbit determination (IOD) using method Laplace. The second part is about orbit correlation. The height of perigee, inclination and right ascension of ascending node (RAAN) are chosen as characteristic quantity in the orbit correlation considering the character of the error of IOD process. The third part is about the POD process. In order to enlarge the convergence area and to modify the initial value of the orbit elements, two strategies of reducing the number of estimation parameters is investigated. The last part of this chapter is about the application of new object cataloging which shows the effectiveness of the method of uncorrelated data process.