The Research Of Orbit Determination About CHAMP Satellite

Satellite navigation system is based on precise orbit determination and prediction. The precision of its orbit is an important capacity index for satellite navigation system. To determine the precise orbits of low-orbit satellites is one of the hotspots in satellite geodesy studies nowadays. It is a key problem that how to improve the orbit precision of the low-orbit satellites in satellite navigation technology study.The thesis first researches the basic theories about precise orbit determination systematically, including time systems and coordinate systems and perturbing force models in equations of satellite motion. Then, it investigates how perturbing force models affect the low-orbit satellites equipped GPS receivers on board and how to pre-treat the observation data of on-board GPS receivers. At last, the author realizes the orbit determination of low-orbit satellites from absolute determining, dynamic method determination and Kalman filtering by the program developed on his own. And the results reach a good precision.The thesis includes following investigations:1, Time systems and coordinate systems are worked over systematically: At practical requests of satellite orbit determination, conversions among various coordinate systems, and how to compute orbit-determination parameters with JPL ephemeris in precise orbit determination are discussed. Further more, basic block diagrams and detailed formulas are presented.2, Perturbing force models in equations of motion are introduced: Perturbing force models of satellite motion are not only the basic physical models of precise satellite orbit determination, but also the basic start to determine the orbits of satellites by dynamic method. Various perturbing force models picturing satellites motion states are introduced in detail, and formulas deduction are introduced too. Particularly, the author analyses the functions of different perturbing force models in equations of motion. Besides, how the model errors affect the equations of motion is analysed from the direction of error propagation. The different effects on orbit determination caused by different models are compared by CHAMP satellites measured data provided by GFZ. Some useful conclusions are educed.3, The problem of data quality control in on-board GPS orbit determination is analyzed systematically. Linear combinations of GPS non-differential measured...