DORIS and GPS monitoring of the Gavdos calibration site in Crete

Abstract Due to its specific geographical location as well as its geodetic equipment (DORIS, GNSS, microwave transponder and tide gauges), the Gavdos station in Crete, Greece is one of the very few sites around the world used for satellite altimetry calibration. To investigate the quality of the Gavdos geodetic coordinates and velocities, we analyzed and compared here DORIS and GPS-derived results obtained during several years of observations. The DORIS solution is the latest ignwd11 solution at IGN, expressed in ITRF2008, while the GPS solution was obtained using the GAMIT software package. Current results show that 1–2 mm/yr agreement can be obtained for 3-D velocity, showing a good agreement with current geophysical models. In particular, the agreement obtained for the vertical velocity is around 0.3–0.4 mm/yr, depending on the terrestrial reference frame. As a by-product of these geodetic GPS and DORIS results, Zenith Tropospheric Delays (ZTDs) estimations were also compared in 2010 between these two techniques, and compared to ECMWF values, showing a 6.6 mm agreement in dispersion without any significant difference between GPS and DORIS (with a 97.6% correlation), but with a 13–14 mm agreement in dispersion when comparing to ECMWF model (with only about 90% correlation for both techniques). These tropospheric delay estimations could also provide an external calibration of the tropospheric correction used for the geophysical data of satellite altimetry missions.

[1]  Demitris Paradissis,et al.  Global Positioning System constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus , 2000 .

[2]  Erricos C. Pavlis,et al.  The GAVDOS Mean Sea Level and Altimeter Calibration Facility: Results for Jason-1 , 2004 .

[3]  M. Meindl,et al.  GNSS processing at CODE: status report , 2009 .

[4]  S. Owen,et al.  The angular velocities of the plates and the velocity of Earth's centre from space geodesy , 2010 .

[5]  Z. Altamimi,et al.  ITRF2008: an improved solution of the international terrestrial reference frame , 2011 .

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

[7]  T. Dixon,et al.  Noise in GPS coordinate time series , 1999 .

[8]  C. Demets,et al.  Geologically current motion of 56 plates relative to the no‐net‐rotation reference frame , 2011 .

[9]  John C. Ries,et al.  Current status of the doris pilot experiment and the future international doris service , 2002 .

[10]  P. Bonnefond,et al.  Absolute Calibration of Jason-1 and Jason-2 Altimeters in Corsica during the Formation Flight Phase , 2010 .

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

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

[13]  W. Thatcher,et al.  New constraints on the active tectonic deformation of the Aegean , 2004 .

[14]  M. Seitz,et al.  Analysis of the DORIS contributions to ITRF2008 , 2010 .

[15]  E. J. Christensen,et al.  TOPEX/POSEIDON mission overview , 1994 .

[16]  Urs Hugentobler,et al.  DORIS data analysis at Geodetic Observatory Pecný using single-satellite and multi-satellite geodetic solutions , 2010 .

[17]  Bruce J. Haines,et al.  The Harvest Experiment: Calibration of the Climate Data Record from TOPEX/Poseidon, Jason-1 and the Ocean Surface Topography Mission , 2010 .

[18]  Carine Bruyninx,et al.  Regional densification of the IGS in europe using the EUREF permanent GPS network (EPN) , 2001 .

[19]  Peter Steigenberger,et al.  Multi-technique comparison of troposphere zenith delays and gradients during CONT08 , 2011 .

[20]  Carey E. Noll,et al.  The crustal dynamics data information system: A resource to support scientific analysis using space geodesy , 2010 .

[21]  Pascal Willis,et al.  Isostatic stability of the East Antarctic station Dumont d’Urville from long-term geodetic observations and geophysical models , 2009 .

[22]  Pascal Willis,et al.  Error Analysis of Weekly Station Coordinates in the DORIS Network , 2006 .

[23]  Paul Tregoning,et al.  Absolute Calibration in Bass Strait, Australia: TOPEX, Jason-1 and OSTM/Jason-2 , 2011 .

[24]  J. Nocquet,et al.  Plate kinematics of Nubia–Somalia using a combined DORIS and GPS solution , 2006 .

[25]  Demitris Paradissis,et al.  GPS constraints on continental deformation in the Africa‐Arabia‐Eurasia continental collision zone and implications for the dynamics of plate interactions , 2005 .

[26]  Pascal Willis,et al.  Improving DORIS geocenter time series using an empirical rescaling of solar radiation pressure models , 2009 .

[27]  Y. Bar-Sever,et al.  Estimating horizontal gradients of tropospheric path delay with a single GPS receiver , 1998 .

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

[29]  Panagiotis Partsinevelos,et al.  Ascending and Descending Passes for the Determination of the Altimeter Bias of Jason Satellites using the Gavdos Facility , 2011 .

[30]  B. Pettersen,et al.  The kinematics of Ny-Ålesund from space geodetic data , 2009 .

[31]  F. Molteni,et al.  The ECMWF Ensemble Prediction System: Methodology and validation , 1996 .

[32]  Pascal Willis,et al.  External validation of the GRACE GGM01C gravity field using GPS and DORIS positioning results , 2004 .

[33]  Pascal Willis,et al.  An inter-comparison of zenith tropospheric delays derived from DORIS and GPS data , 2010 .

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

[35]  K. Palamartchouk,et al.  A new velocity field for Greece: Implications for the kinematics and dynamics of the Aegean , 2010 .

[36]  Pascal Willis,et al.  Contributions of the French Institut Géographique National (IGN) to the International DORIS Service , 2010 .

[37]  J. Barriot,et al.  Evidence for a slow subsidence of the Tahiti Island from GPS, DORIS, and combined satellite altimetry and tide gauge sea level records , 2010 .

[38]  Pascal Willis.  Analysis of a Possible Future Degradation in the DORIS Geodetic Results Related to Changes in the Satellite Constellation , 2007 .

[39]  Pascal Willis,et al.  Refining DORIS atmospheric drag estimation in preparation of ITRF2008 , 2010 .

[40]  Robert W. King,et al.  Estimating regional deformation from a combination of space and terrestrial geodetic data , 1998 .

[41]  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 .