HR: 09:15h
AN: G51D-06    [Abstracts]
TI: Consistent Long-Time Series of GPS Satellite Antenna Phase Center Corrections
AU: Steigenberger, P
EM: steigenberger@bv.tum.de
AF: Forschungseinrichtung Satellitengeod{\"a}sie, TU M{\"u}nchen, Arcisstra{\ss}e 21, M{\"u}nchen, 80333 Germany
AU: Schmid, R
EM: schmid@bv.tum.de
AF: Institut f{\"u}r Astronomische und Physikalische Geod{\"a}sie, TU M{\"u}nchen, Arcisstra{\ss}e 21, M{\"u}nchen, 80333 Germany
AU: * Rothacher, M
EM: rothacher@bv.tum.de
AF: Forschungseinrichtung Satellitengeod{\"a}sie, TU M{\"u}nchen, Arcisstra{\ss}e 21, M{\"u}nchen, 80333 Germany
AB: The current IGS processing strategy disregards satellite antenna phase center variations (pcvs) depending on the nadir angle and applies block-specific phase center offsets only. However, the transition from relative to absolute receiver antenna corrections presently under discussion necessitates the consideration of satellite antenna pcvs. Moreover, studies of several groups have shown that the offsets are not homogeneous within a satellite block. Manufacturer specifications seem to confirm this assumption. In order to get best possible antenna corrections, consistent ten-year time series (1994-2004) of satellite-specific pcvs and offsets were generated. This challenging effort became possible as part of the reprocessing of a global GPS network currently performed by the Technical Universities of Munich and Dresden. The data of about 160 stations since the official start of the IGS in 1994 have been reprocessed, as today's GPS time series are mostly inhomogeneous and inconsistent due to continuous improvements in the processing strategies and modeling of global GPS solutions. An analysis of the signals contained in the time series of the phase center offsets demonstrates amplitudes on the decimeter level, at least one order of magnitude worse than the desired accuracy. The periods partly arise from the GPS orbit configuration, as the orientation of the orbit planes with regard to the inertial system repeats after about 350 days due to the rotation of the ascending nodes. In addition, the rms values of the X- and Y-offsets show a high correlation with the angle between the orbit plane and the direction to the sun. The time series of the pcvs mainly point at the correlation with the global terrestrial scale. Solutions with relative and absolute phase center corrections, with block- and satellite-specific satellite antenna corrections demonstrate the effect of this parameter group on other global GPS parameters such as the terrestrial scale, station velocities, the geocenter position or the tropospheric delays. Thus, deeper insight into the so-called `Bermuda triangle' of several highly correlated parameters is given.
DE: 1229 Reference systems
DE: 1241 Satellite orbits
DE: 1247 Terrestrial reference systems
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting