SIRGAS was initially realized by two GPS campaigns, one in 1995 (SIRGAS95) with 58 stations, and one in 2000 (SIRGAS2000) with 184 stations. Today, SIRGAS is realized by 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 SIRGAS Continuously Operating Network (SIRGAS-CON) is currently composed by more than 200 permanently operating GNSS sites, 48 of them belonging to the global IGS network. The operational performance of SIRGAS-CON is based on the contribution of more than 50 Latin American organizations, which install and operate the permanent stations and voluntarily provide the tracking data for the weekly processing of the network. Since more and more Latin American countries are qualifying their national reference frames by installing GNSS continuously operating stations and these stations shall be consistently integrated into the continental reference frame, the SIRGAS-CON network comprises two hierarchy levels:

1. One core network (SIRGAS-CON-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. Several densification sub-networks (SIRGAS-CON-D) providing accesibility to the reference frame at local levels. These densification subnetworks correspond to the national reference frames realized by continuously operating stations. At the moment, there are three SIRGAS-CON-D sub-networks (a northern, a middle, and a southern one), but in the future, there shall be given so many SIRGAS-CON-D sub-networks as countries in the region.

The SIRGAS-CON-C network is processed by the IGS-RNAAC-SIR (i.e. DGFI, Germany). The SIRGAS-CON-D sub-networks are computed by the SIRGAS Local Processing Centres: CIMA (Argentina), IBGE (Brazil), IGAC (Colombia),  IGM-Ec (Ecuador), SGM-Uy (Uruguay), and LFGS-LUZ (Venezuela). These processing centres deliver loosely constrained weekly solutions for the densification SIRGAS-CON-D sub-networks, which are combined with the SIRGAS-CON-C core network to get homogeneous precision for station positions and velocities in a continental level. The processing strategy guarantees that each regional SIRGAS-CON station is included in three individual solutions. The SIRGAS Combination Centres are DGFI and IBGE.

The final SIRGAS station position and velocities are provided by the IGS-RNAAC-SIR. The main products are: loosely constrained weekly station coordinates in SINEX format for the IGS polyhedron solutions; weekly coordinates aligned to the ITRF for applications in Latin America; and multi-annual (cumulative) solutions (coordinates + velocities) for practical and scientific applications requiring time depending positioning.