Report On The Sirgas-Con Combined Solution, By Ibge Analysis Center

Since the last SIRGAS meeting in May, 2008, IBGE has been playing a role as Processing and Combination Center of SIRGAS-CON network, in order to provide support to the SIRGAS reference frame. The SIRGAS-CON densification network is composed now by 150 continuously operating GNSS permanent stations and this number is increasing continuously. In the same SIRGAS meeting some aspects related to the network coordination were discussed in order to correct several factors that were affecting the quality of solutions, e. g. equipment changes, which may cause a discontinuity in the coordinate time series.One of the tasks of the IBGE Analysis Center is the combination of weekly solutions computed by each SIRGAS-CON Processing Center and to generate a cumulative solution aligned to the IGS05 reference frame. In this paper four combination strategies were explored using the minimum constraints approach, preserving the original characteristics of the weekly solutions and providing the alignment to the IGS05 reference frame. The procedures adopted for the combination and statistical analysis of results are presented in this paper.