The current realization of SIRGAS is a network of continuously operating GNSS stations with precisely known positions (referred to an specific reference epoch) and their changes with time (station velocities). This network comprises:
The SIRGAS-C network is processed by the IGS RNAAC SIRGAS (i.e. DGFI-TUM. Germany). The SIRGAS-N national networks are computed by the Latin American SIRGAS Processing Centres: CEPGE (Ecuador), IBGE (Brazil), IGAC (Colombia), IGM-Cl (Chile), IGN-Ar (Argentina), INEGI (Mexico), IGM-Uy (Uruguay) and USC (Chile). These processing centres deliver loosely constrained weekly solutions for the SIRGAS-N national networks, which are combined with the SIRGAS-C core network to get homogeneous precision for station positions and velocities. The processing strategy guarantees that each regional SIRGAS station is included in three individual solutions.
DGFI-TUM acts as a SIRGAS Combination Centre since August 2008 and provides loosely constrained weekly station positions in SINEX format to be included in the IGS polyhedron solutions and for the computation of mult-year solutions; weekly station positions; and multi-year (cumulative) solutions (positions + velocities) for practical and scientific applications requiring time depending positioning. The weekly positions are especially useful when strong earthquakes cause co-seismic displacements or strong relaxation motions at the SIRGAS stations disabling the use of previous coordinates. The multi-year solutions provide the most accurate and up-to-date SIRGAS station positions and velocities. They are used for the realization and maintenance of the SIRGAS reference frame between two releases of the ITRF. While a new ITRF release is published more or less every five years, the SIRGAS reference frame multi-year solutions are updated every one or two years.
Dr.-Ing. Laura Sanchez
Tel. +49 89 23031-1295
Fax +49 89 23031-1240