José Duarte Correia, Roberto Teixeira Luz and Valiria Mendonça Guimarães IBGE, Brazil
The Brazil Institute of Geography and Statistics (IBGE) is the responsible for the geodetic positioning and periodic control of the tide gauges benchmarks of the Brazilian GLOSS stations, as a solicitation of the Directorate of Hydrography and Navigation (DHN), of the Brazilian Navy that coordinates the GLOSS Program in Brazil. This work may be done in two different ways: (I) high precision spirit levelling, connecting the tides gauges benchmarks to the Brazilian Primary Vertical Control Network; (II) geocentric positioning with GPS, according to the recommendations of the Permanent Service for Mean Sea Level (PSMSL).
Until October, 1993, the situation of the geodetic positioning of the Brazilian GLOSS stations was the following:
- Ponta da Madeira: spirit levelling
- Penedos de Sao Pedro e Sao Paulo: GPS
- Ilha de Fernando de Noronha: GPS
- Ilha de Itaparica: not connected
- Ilha de Trindade: GPS
- Rio de Janeiro: spirit levelling and GPS
- Cananbia: spirit levelling
- Rio Grande: not connected
The data related to the positioning of these stations in being processed
to be sent to DHN. IBGE is making efforts to conclude the positioning,
by both the ways (except in the oceanic islands), until June 1994. IBGE
would like to thanks the cooperation of DHN, the Federal University of
Paraná (UFPR), the Federal University of Pernambuco and University
of São Paulo (USP) during operations at the oceanic islands (Trindade,
Fernando de Noronha e Penedos de São Pedro e São Paulo).