The recently adopted ITRF05 (GPS week 1400) Frame should improve Spatial Geodetic Positioning, especial/y GPS Vector Processing. As is wel/ known, GPS frames must be scaled in order to be consistent with other Spatial Techniques, mainly VLBJ, being IGbOO a very significant example. A new IGS recommendation is the usage of Absolute Antenna Phase Center Variations, which should diminish the influence of the elevation Angle of the Satellites. The new Absolute PCVs are used also from GPS week 1400 to compute Satel/ite Orbits in the derived 1GS05 Frame. These two improvements must be ve/y carefully analyzed: on the one hand we have ITRF05, which is aligned to the 1TRFOOframe, and, on the other hand we have IGS05, which is not consistent with the lTRF05 Frame due to the newly adopted Absolute PCVs. Currently, no precise IGS05 Coordinates are known and afew years should pass to get accurate Coordinates and Velocities, but lo get accurate ETRS89 Coordinates we do need lo transform from lGS05 to the ITRF= frame to get the final ETRS89 Coordinales. 1n this paper, time series of two GPS Networks are analyzed. the RGAPA (Red Geodésica Activa del Principado de Asturias) and the RGG (Red GPS de Gipuzkoa) have been used /0 check (he suitability of (he proposed IGS05-> 1TRF05 transforma/ion (lGSMAIL-5447) as wel/ as to check the injluence of such Transformation in the final ETRS89 Coordinates (Altamimi et al., 2007).

ZURUTUZA, J. "Análisis de las transformaciones IGS05ITRF05ETRS89". En: 6ª Asamblea Hispano Portuguesa de Geodesia e Geofísica, (Tomar, 11-14 de febrero de 2008)

Peer reviewed