Cumulative solutions for estimating the kinematics of the SIRGAS-CON network are regularly performed. The combined adjustment is done with the program ADDNEQ of the Bernese Software and it is based on the loosely constrained weekly solutions (SINEX files) submitted by the IGS-RNACC-SIR to the IGS Global Analysis Centres. The analysis includes the identification of position discontinuities due to episodic events such as co-seismic displacements or antenna configuration changes, in order to set up the appropriate parameters in the adjustment. The station coordinates (associated to a reference epoch) and velocities are estimated by constraining the IGS05 stations existing in the region to their reference values.

Given that IGS standards include absolute calibration values for the antenna phase centre corrections since GPS week 1400, the SIRGAS-CON weekly solutions from January 2000 to November 2006 computed with relative phase centre corrections and referred to former ITRF solutions were reprocessed including absolute phase centre corrections and IGS05 as reference frame.

Based on this reprocessing, the IGS-RNAAC-SIR generated a new multi year solution (SIR09P01) covering the time period from January 2, 2000 (GPS week 1043) to January 3, 2009 (GPS week 1512). Stations operating less than two years were excluded. After analysing time series for coordinates, discontinuities were identified and for the corresponding stations different time spans were set up. These time spans are properly included in the coordinate, velocity, and SINEX files.

SIR09P01 refers to the IGS05 reference frame, epoch 2005.0. Its coordinates (SIR09P01.CRD), velocities (SIR09P01.VEL), and SINEX file (SIR09P01.SNX) are also available at ftp://ftp.dgfi.badw-muenchen.de/pub/gps/SIRGAS/