Research On The Orbit Determination Style Of TDRS And Precision Analysis

To keep up with the development of Space-technology, powerful country are perfecting, founding or preparing their Tracking and Data Relay Satellite System(TDRSS). The system plays an important role in the development of Space-technology for its high coverage, high transmission ratio and capability of multi-object controlling. In our country, TDRSS has been on the schedule, and expert department has been constituted.The TDRSSs of different countries are presented and the relevant theories of satellite orbit determination are discussed. Based on the work above, the combined orbit determination (COD) is studied deeply, and the different COD modes are analyzed and compared by emulational calculation. At last, the ground-based orbit determination and the COD are studied for our country's idiographic situation, and some emulational results are given.The main conclusions are:1) Based on the visibility theory brings forward in the paper, the percentage of the visibility between TDRS and the low orbit satellite(LEO) is more than 60 percents for the single TDRS and single LEO system(the single-single system). In the double TDRS and single LEO system(the double-single system), that increased to more 90 percents, as well as in the single TDRS and double LEO system(the single-double system), both of which are advantageous to data acquire and orbit determination structure than the single-single system.2) Under the three modes of the COD( the single-single system, the double-single system, and the single-double system), the position precision after the orbit determination obviously improves for about two magnitudes, and the COD can improve the orbit precision of the LEO more sharply than that of the TDRS in the syetem. The orbit determination precision of the single-double system is the best.3) Compared to the single-single system, thanks to the second chain, the double-single system can not only saves the valuable TDRS's employ time but also loosen the restriction to survey noise, and at the meantime improves the precision of the new TDRS to that of the TDRS in the single-single system. The single-double system can not only improves the precision of the satellites in the single-single system, but can also improve the precision of new user spacecraft to that of the user spacecraft in the single-single system, and at the same time the sampling time is shortened.4) When it comes to our country's situation, we take the survey precision as one meter, and do some research of the emulational calculation and the precision analysis on the ground-based orbit determination and the COD. According to the paper, at the beginning of the China's single-TDRS system, three-chain mode is the best choice and also is advised. That's because although the orbit determination precision of the single-single system is better than the single chain ground-based system, it is worse than that of the three chain ground-based system.