Study on Combined Orbit Determination of Navigation Satellites with Ground Tracking Observation and Cross-link Ranging Observation

W. Liu, Z. Li, X. Gong

Abstract:	This paper firstly discusses some critical issues of combined orbit determination (COD) of navigation satellites with ground tracking observation and cross-link ranging observation, including observation simulation method, force models, numerical integrator, and parameter estimation method. Then based on the COD analysis software package developed by us,effects of the number of ground tracking stations and their geographical distribution, as well as random error and remaining systematic errors in ranging observations on accuracy of COD are studied by means of simulation. Calculation results indicate that if taken user range error (URE) =6m as evaluation criterion, then only using tracking data of six ground stations in China would not satisfy previous demands, while using observations of 17 ground stations which are well-distributed worldwide could meet the criterion very well, although there are many difficulties to set up ground stations like that. If navigation satellites have capabilities of cross-link ranging and data transmitting, then they can not only form autonomous navigation (Autonav) system in wartime quickly, but also solve the difficulty of uniformly setting up ground stations globally by COD during peacetime. We also find that when random errors in ranging observations increase by 15 times, URE only increases by 1.2 times. That’s the reason why pseudorange observations are widely used in COD and Autonav applications. However, effect of systematic errors remained in observations on accuracy of COD is very serious, so calibration work must be treated carefully. These conclusions are very significant for Chinese compass navigation satellite system (CNSS).
Published in:	Proceedings of the 22nd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2009) September 22 - 25, 2009 Savannah International Convention Center Savannah, GA
Pages:	1561 - 1572
Cite this article:	Liu, W., Li, Z., Gong, X., "Study on Combined Orbit Determination of Navigation Satellites with Ground Tracking Observation and Cross-link Ranging Observation," Proceedings of the 22nd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2009), Savannah, GA, September 2009, pp. 1561-1572.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In