Instituto Brasileiro de Geografia e Estatística

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Geodesy

SIRGAS - Processing Center

Results

The SIRGAS Processing Center generates files containing weekly results from the sub-network processed by IBGE in the SINEX (SNX) format. Presently, around 120 stations belonging to the SIRGAS-CON Network are included in this processing activity. They are located in Argentina, Bolivia, Brazil, French Guyana, Peru, Suriname and Uruguay.

The files here presented are loosely constrained and can be used in the adjustment of differential solutions, in the densification of any given area. These files are available three weeks after the date of the observation. The following denomination is adopted for the SINEX files:

IBGwwww7.SNX ? loosely contrained solution
(where wwww =GPS week)

The files are available on: ftp://geoftp.ibge.gov.br/informacoes_sobre_posicionamento_geodesico/sirgas/processamento/

The strategies, parameters and models adopted to generate the weekly results are:

 

Types of Observation Carrier Phase Double-Difference
Softwares used Bernese 5.0 (up to GPS week 1779) and Bernese 5.2 (since GPS week 1780)
Data collection interval 30 sec
Elevation Cut-off Angle 03º
Baseline Selection Strategy OBS-MAX (according to the quantity of observation in common)
Orbit/EOP final IGS - IGS08
"A priori" Troposphere Model

Mapping Function (Wet_VMF Vienna Mapping Functions)
http://ggosatm.hg.tuwien.ac.at/delay.html

Ambiguities QIF (Quasi Ionosphere Free) strategy; Global Ionosphere Maps produced by CODE (Center for Orbit Determination in Europe)
Ocean Tide Model FES2004
Phase Center Variation PHAS_COD.I05 (Absolute – IGS05) Period: 1199 to 1631
PHAS_COD.I08 (Absolute – IGS08) Period: 1632 to 1779
PHAS_IGS.08 (Absolute – IGS08) Period: since 1780
"A priori" Coordinates and Velocities IGS05 Period: 1199 to 1631 (1199 to 1399 – Reprocessed!)
IGS08 Period: 1632 to 1708
IGb08 Period: since 1709
Daily Solutions loosely constrained (all stations constrained to 1 meter)
Weekly Solutions IGS stations (BRAZ, CHPI, CONZ, CRO1, ISPA, LPGS, MANA, OHIG,  SANT, SCUB and  UNSA) used to constrain the weekly solution to ±0,1mm
Weekly and daily solutions formats SINEX Format (SNX files)