Quality assessment of GPS reprocessed terrestrial reference frame

The International GNSS Service (IGS) contributes to the construction of the International Terrestrial Reference Frame (ITRF) by submitting time series of station positions and Earth Rotation Parameters (ERP). For the first time, its submission to the ITRF2008 construction is based on a combination of entirely reprocessed GPS solutions delivered by 11 Analysis Centers (ACs). We analyze the IGS submission and four of the individual AC contributions in terms of the GNSS frame origin and scale, station position repeatability and time series seasonal variations. We show here that the GPS Terrestrial Reference Frame (TRF) origin is consistent with Satellite laser Ranging (SLR) at the centimeter level with a drift lower than 1 mm/year. Although the scale drift compared to Very Long baseline Interferometry (VLBI) and SLR mean scale is smaller than 0.4 mm/year, we think that it would be premature to use that information in the ITRF scale definition due to its strong dependence on the GPS satellite and ground antenna phase center variations. The new position time series also show a better repeatability compared to past IGS combined products and their annual variations are shown to be more consistent with loading models. The comparison of GPS station positions and velocities to those of VLBI via local ties in co-located sites demonstrates that the IGS reprocessed solution submitted to the ITRF2008 is more reliable and precise than any of the past submissions. However, we show that some of the remaining inconsistencies between GPS and VLBI positioning may be caused by uncalibrated GNSS radomes.

[1]  Thomas A. Herring,et al.  Impact of a priori zenith hydrostatic delay errors on GPS estimates of station heights and zenith total delays , 2006 .

[2]  M. Bouin,et al.  Rates of sea‐level change over the past century in a geocentric reference frame , 2009 .

[3]  Zuheir Altamimi,et al.  ITRF2000: A new release of the International Terrestrial Reference Frame for earth science applications , 2002 .

[4]  F. LeMoine,et al.  A reassessment of global and regional mean sea level trends from TOPEX and Jason‐1 altimetry based on revised reference frame and orbits , 2007 .

[5]  M. Zhong,et al.  Contributions of thermal expansion of monuments and nearby bedrock to observed GPS height changes , 2009 .

[6]  J. Ray,et al.  Effect of the satellite laser ranging network distribution on geocenter motion estimation , 2009 .

[7]  R. Ferland,et al.  The IGS-combined station coordinates, earth rotation parameters and apparent geocenter , 2009 .

[8]  G. Blewitt,et al.  A New Global Mode of Earth Deformation: Seasonal Cycle Detected , 2001, Science.

[9]  Martin Schmitz,et al.  Impact of Near-Field Effects on the GNSS Position Solution , 2008 .

[10]  Peter Steigenberger,et al.  Reprocessing of a global GPS network , 2006 .

[11]  Jeffrey P. Walker,et al.  THE GLOBAL LAND DATA ASSIMILATION SYSTEM , 2004 .

[12]  J. Ray,et al.  Anomalous harmonics in the spectra of GPS position estimates , 2008 .

[13]  Paul Tregoning,et al.  Atmospheric effects and spurious signals in GPS analyses , 2009 .

[14]  Z. Altamimi,et al.  ITRF2005 : A new release of the International Terrestrial Reference Frame based on time series of station positions and Earth Orientation Parameters , 2007 .

[15]  David LaVallee,et al.  Higher‐order ionospheric effects on the GPS reference frame and velocities , 2009 .

[16]  Dirk Behrend,et al.  The International VLBI Service for Geodesy and Astrometry (IVS): current capabilities and future prospects , 2007 .

[17]  Galina Dick,et al.  Impact of GPS satellite antenna offsets on scale changes in global network solutions , 2005 .

[18]  Xavier Collilieux.  Analyse des séries temporelles de positions des stations de géodésie spatiale : application au Repère International de Référence Terrestre (ITRF) , 2008 .

[19]  Peter J. Clarke,et al.  Geocenter motions from GPS: A unified observation model , 2006 .

[20]  Peter Steigenberger,et al.  Comparison of GMF/GPT with VMF1/ECMWF and implications for atmospheric loading , 2009 .

[21]  Claudio Abbondanza,et al.  Gravity-dependent signal path variation in a large VLBI telescope modelled with a combination of surveying methods , 2009 .

[22]  Gerhard Beutler,et al.  Contribution of SLR tracking data to GNSS orbit determination , 2007 .

[23]  H. Schuh,et al.  Short Note: A global model of pressure and temperature for geodetic applications , 2007 .

[24]  T. Artz,et al.  VLBI terrestrial reference frame contributions to ITRF2008 , 2010 .

[25]  Peter Steigenberger,et al.  Realization of the Terrestrial Reference System by a reprocessed global GPS network , 2008 .

[26]  Pascal Willis,et al.  Terrestrial reference frame effects on global sea level rise determination from TOPEX/Poseidon altimetric data , 2004 .

[27]  Peter Steigenberger,et al.  Generation of a consistent absolute phase-center correction model for GPS receiver and satellite antennas , 2007 .

[28]  Michael B. Heflin,et al.  Seasonal and interannual global surface mass variations from multisatellite geodetic data , 2006 .

[29]  Chris Rizos,et al.  The International GNSS Service in a changing landscape of Global Navigation Satellite Systems , 2009 .

[30]  M. Watkins,et al.  GRACE Measurements of Mass Variability in the Earth System , 2004, Science.

[31]  Xavier Collilieux,et al.  Comparison of very long baseline interferometry, GPS, and satellite laser ranging height residuals from ITRF2005 using spectral and correlation methods , 2007 .

[32]  Gerhard Beutler,et al.  Validation of GNSS orbits using SLR observations , 2004 .

[33]  Peter Steigenberger,et al.  Annual deformation signals from homogeneously reprocessed VLBI and GPS height time series , 2009 .

[34]  H. Schuh,et al.  Global Mapping Function (GMF): A new empirical mapping function based on numerical weather model data , 2006 .

[35]  Ch. Reigber,et al.  Satellite antenna phase center offsets and scale errors in GPS solutions , 2003 .

[36]  Matt A. King,et al.  Long GPS coordinate time series: Multipath and geometry effects , 2009 .

[37]  Xavier Collilieux,et al.  IGS contribution to the ITRF , 2009 .