ITRF2008: an improved solution of the international terrestrial reference frame

ITRF2008 is a refined version of the International Terrestrial Reference Frame based on reprocessed solutions of the four space geodetic techniques: VLBI, SLR, GPS and DORIS, spanning 29, 26, 12.5 and 16 years of observations, respectively. The input data used in its elaboration are time series (weekly from satellite techniques and 24-h session-wise from VLBI) of station positions and daily Earth Orientation Parameters (EOPs). The ITRF2008 origin is defined in such a way that it has zero translations and translation rates with respect to the mean Earth center of mass, averaged by the SLR time series. Its scale is defined by nullifying the scale factor and its rate with respect to the mean of VLBI and SLR long-term solutions as obtained by stacking their respective time series. The scale agreement between these two technique solutions is estimated to be 1.05 ± 0.13 ppb at epoch 2005.0 and 0.049 ± 0.010 ppb/yr. The ITRF2008 orientation (at epoch 2005.0) and its rate are aligned to the ITRF2005 using 179 stations of high geodetic quality. An estimate of the origin components from ITRF2008 to ITRF2005 (both origins are defined by SLR) indicates differences at epoch 2005.0, namely: −0.5, −0.9 and −4.7 mm along X, Y and Z-axis, respectively. The translation rate differences between the two frames are zero for Y and Z, while we observe an X-translation rate of 0.3 mm/yr. The estimated formal errors of these parameters are 0.2 mm and 0.2 mm/yr, respectively. The high level of origin agreement between ITRF2008 and ITRF2005 is an indication of an imprecise ITRF2000 origin that exhibits a Z-translation drift of 1.8 mm/yr with respect to ITRF2005. An evaluation of the ITRF2008 origin accuracy based on the level of its agreement with ITRF2005 is believed to be at the level of 1 cm over the time-span of the SLR observations. Considering the level of scale consistency between VLBI and SLR, the ITRF2008 scale accuracy is evaluated to be at the level of 1.2 ppb (8 mm at the equator) over the common time-span of the observations of both techniques. Although the performance of the ITRF2008 is demonstrated to be higher than ITRF2005, future ITRF improvement resides in improving the consistency between local ties in co-location sites and space geodesy estimates.

[1]  W. Farrell.  Deformation of the Earth by surface loads , 1972 .

[2]  Effects of adopting new precession, nutation and equinox corrections on the terrestrial reference frame , 1983 .

[3]  F. Sansò.  II Hotine-Marussi Symposium on Mathematical Geodesy , 1988 .

[4]  Jean Kovalevsky,et al.  Reference frames in astronomy and geophysics , 1989 .

[5]  J. Ray,et al.  Measurements of length of day using the Global Positioning System , 1996 .

[6]  M. K. Cheng,et al.  Geocenter variations caused by atmosphere, ocean and surface ground water , 1997 .

[7]  M. Greff-Lefftz.  Secular variation of the geocenter , 2000 .

[8]  Claude Boucher,et al.  A review of algebraic constraints in terrestrial reference frame datum definition , 2001 .

[9]  Establishing Global Reference Frames. Nonlinear, Temporal, Geophysical and Stochastic Aspects , 2001 .

[10]  Michael R Pearlman,et al.  THE INTERNATIONAL LASER RANGING SERVICE , 2007 .

[11]  R. Langley,et al.  Improved mapping functions for atmospheric refraction correction in SLR , 2002 .

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

[13]  Claude Boucher,et al.  New trends for the realization of the international terrestrial reference system , 2002 .

[14]  P. Bird.  An updated digital model of plate boundaries , 2003 .

[15]  E. C. Pavlis,et al.  High‐accuracy zenith delay prediction at optical wavelengths , 2004 .

[16]  Zuheir Altamimi,et al.  ITRF2000: From Theory to Implementation , 2004 .

[17]  Yehuda Bock,et al.  Error analysis of continuous GPS position time series , 2004 .

[18]  A. Dermanis.  The rank deficiency in estimation theory and the definition of reference systems , 2004 .

[19]  Luca Vittuari,et al.  Surveying co-located space-geodetic instruments for ITRF computation , 2004 .

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

[21]  Local ties between the reference points at the Transportable Integrated Geodetic Observatory (TIGO) in Concepcion/Chile , 2005 .

[22]  T. Klügel,et al.  Local ties between the reference points at the Fundamentalstation Wettzell , 2005 .

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

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

[25]  Jim R. Ray,et al.  New global positioning system reference station in Brazil , 2006 .

[26]  H. Schuh,et al.  Troposphere mapping functions for GPS and very long baseline interferometry from European Centre for Medium‐Range Weather Forecasts operational analysis data , 2006 .

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

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

[29]  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 .

[30]  Zuheir Altamimi,et al.  Variance Component Estimation for Combination of Terrestrial Reference Frames , 2007 .

[31]  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 .

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

[33]  V. Luceri,et al.  Attempts to separate apparent observational range bias from true geodetic signals , 2008 .

[34]  Pascal Willis,et al.  IDS contribution to ITRF2008 , 2009 .

[35]  Axel Nothnagel,et al.  Conventions on thermal expansion modelling of radio telescopes for geodetic and astrometric VLBI , 2009 .

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

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

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

[39]  E. Pavlis,et al.  The ILRS contribution to ITRF2008 , 2009 .

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

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

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

[43]  A Quasi-Optimal, Consistent Approach for Combination of UT1 and LOD , 2009 .

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

[45]  Xavier Collilieux,et al.  Global sea-level rise and its relation to the terrestrial reference frame , 2009 .

[46]  Y. Bar-Sever,et al.  Systematic biases in DORIS-derived geocenter time series related to solar radiation pressure mis-modeling , 2009 .

[47]  L. Metivier,et al.  Dynamic mantle density heterogeneities and global geodetic observables , 2010 .

[48]  Pascal Willis,et al.  The International DORIS Service (IDS): Toward maturity , 2010 .

[49]  P. Willis,et al.  DORIS: Scientific applications in geodesy and geodynamics , 2010 .

[50]  Z. Altamimi,et al.  On secular geocenter motion: The impact of climate changes , 2010 .

[51]  Z. Altamimi,et al.  Quality Assessment of the IDS Contribution to ITRF2008 , 2010 .

[52]  Xavier Collilieux,et al.  Impact of loading effects on determination of the International Terrestrial Reference Frame , 2010 .

[53]  Xavier Collilieux,et al.  Topographically induced height errors in predicted atmospheric loading effects , 2010 .

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

[55]  Claudio Abbondanza,et al.  Height bias and scale effect induced by antenna gravitational deformations in geodetic VLBI data analysis , 2011 .

[56]  A. Dermanis,et al.  The Choice of Reference System in ITRF Formulation , 2012 .