Vertical component

During the SIRGAS meeting held at the IAG Scientific Meeting, in September 1997, in Rio de Janeiro, further development of the project was discussed, in order to include the vertical component in the reference system. As a result the Working Group III was created, with the objective of promoting the definition and establishment of a unique vertical system for the South American continent.


SIRGAS 2000 realization – Working Groups I and III.


During the first project meeting in October 1993, in Asuncion, Paraguay, the re-observation of the reference network each 5 years was recommended, in order to maintain SIRGAS as a geodetic reference system, able to satisfy current positioning precision standards. With the creation of WG III, the SIRGAS2000 campaign was designed to address the vertical component of the Project.


The vertical reference systems are classically defined through tide gauges (normally one per country) and realized by the vertical network, observed with spirit leveling. The trend for the future is that these networks will be observed by satellite techniques and directly referred to the geoid. The relationship between tide gauges and the geoid, as well as between the orthometric heights and the ellipsoidal ones observad by GPS, is the main objective of WG III. With this purpose, the second SIRGAS campaign included the occupation of all those tide gauges defining the vertical reference system in each country. In addition to that, stations nearby boundaries between countries as well as stations occupied in the 1995 campaign were observed. The observation period was from May 10 to 19, 2000. As happened with the 1995 campaign, the GPS observations will be soon available at IBGE and DGFI servers.

Preliminarily, the stations participating in the new SIRGAS realization (South America, Central and North America, and Caribbean) are: shown in the figure (302 Kb) and table (187 Kb)

SIRGAS 2000 Results coordinates accuraces estimates (23,6 Kb)