A Terrestrial Reference Frame (TRF), coordinates and velocities for South American stations: contributions to Central Andes geodynamics

M V Mackern,M L Mateo,A M Robin,A V Calori

doi:10.5194/adgeo-22-181-2009

Abstract

Abstract. Satellite positioning systems allow the fixing of the location of a point on the Earth's surface with very good precision and accuracy. To do this, however, it is necessary to determine the point coordinates taking account the reference system and the movements that affect them because of tectonic plate movements. These reference systems are materialized by a significant number of continuous measurement stations in South America. In SIRGAS (Sistema de Referencia Geocéntrico para las Américas), there are four Analysis Centers that process the data collected from satellites of the Global Navigation Satellite Systems (GNSS), with the primary purpose to maintain the international terrestrial reference frame through calculation of the coordinates and velocities of the continuous GNSS stations of the SIRGAS-CON Network. In this work, we demonstrate the quality of the solutions from CIMA, one of the SIRGAS official processing centers operating in Mendoza, Argentina, in comparison with other South American processing centers. The importance of precise calculations of coordinates and velocities in a global frame is also shown. Finally, we give estimations of velocities from stations located within deformation zones in the Central Andes.

Highlights

Geodetic measurements from Satellite Laser Ranging (SLR), Very Long Baseline Interferometry (VLBI) and Global Navigation Satellite Systems (GNSS) are a valuable source of information for understanding geodynamics processes such as crustal deformation, post-glacial rebound, Earth rotation irregularities, etc. (Drewes, 2006)
We demonstrate the quality of the solutions from CIMA, one of the SIRGAS official processing centers operating in Mendoza, Argentina, in comparison with other
Good correspondence exists for the observed deformations with respect to the SOAM plate motions between the velocities estimated by CIMA and those estimated by ITRF2005 (Fig. 3)

Summary

Introduction

Geodetic measurements from Satellite Laser Ranging (SLR), Very Long Baseline Interferometry (VLBI) and Global Navigation Satellite Systems (GNSS) are a valuable source of information for understanding geodynamics processes such as crustal deformation, post-glacial rebound, Earth rotation irregularities, etc. (Drewes, 2006). A critical prerequisite to extract reliable geodynamics signals from time series of geodetic coordinates is to ensure the accuracy and the longterm stability of the Terrestrial Reference Frame (TRF) to which the geodetic coordinates are referenced (Altamimi et al, 2007; Angermann et al, 2007). Millimeter-level accuracy and stability over years are needed to ensure that coordinates changes with time are truly related to geodynamics processes rather than to TRF instabilities. TRF instabilities may propagate to the geodetic coordinates through the satellite orbits, which are determined on observations collected from terrestrial tracking stations whose precise coordinates are referenced to the same TRF. SIRGAS (Sistema de referencia Geocéntrico para las Américas) contributes to the TRF for the Caribbean, Central and South American regions, using the highest standards of modern geodesy (Sánchez and Brunini, 2009). I’ve suggested a possible caption for Fig. 3, but you must check for accuracy and make more complete

G P S week

Conclusions