The quality of precise glonass ephemerides

Abstract

To set up a global observation network, and to get experience in modelling GLONASS satellite orbits have been identified as key issues of the International GLONASS Experiment (IGEX), proposed in the late 1997. Thus in October 1998 the official IGEX field campaign was launched as a common effort of more than 60 institutions contributing to the station network as well as offering Data- and Analysis-Center services. In the process, precise satellite orbits, consistent at the 30cm level, were (and still are) calculated by 6 analysis groups on a regular basis. These precise ephemeris are combined and evaluated in order to generate robust, reliable and complete GLONASS orbits. This paper deals with the increasing quality of the calculated GLONASS orbits, even several months after the end of the basic IGEX field campaign, and discusses differences in individual orbit solutions with respect to the orbital geometry. Finally some ideas on a possible continuation of the IGEX effort are given, even under the restriction of a currently disintegrating satellite system.