Recent Results from the IGS Terrestrial Frame Combinations

Abstract

Since February 2010, the Institut Géographique National (IGN) has replaced Natural Resources Canada as the terrestrial frame coordinator of the International GNSS Service (IGS). One important task of this coordination consists in weekly combinations of the solutions provided by nine IGS Analysis Centres into weekly IGS solutions which include station positions, Earth rotation parameters and coordinates of the geocenter. These combinations enable inter-comparisons of the AC solutions. We show that such comparisons reveal systematic distortions between the AC solutions and that relating them to analysis specificities can be a way to improve the quality of both the AC and combined solutions. Because the geocenter determination by GNSS still suffers from mismodeling issues, a rigorous combination of the AC geocenter estimates is not feasible yet. The comparison of recently reprocessed geocenter time series from GNSS and SLR is however encouraging. © Springer-Verlag Berlin Heidelberg 2013.