SIRGAS continuously operating network

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:

  1. One core network (SIRGAS-C), primary densification of ITRF in Latin America, with a good continental coverage and stabile site locations to ensure high long-term stability of the reference frame.
  2. National reference networks (SIRGAS-N) improving the densification of the core network and providing accessibility to the reference frame at national and local levels. Both, the core network and the national networks satisfy the same characteristics and quality; and each station is processed by three analysis centres.

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

80333 München
Tel. +49 89 23031-1295
Fax +49 89 23031-1240