The GPSVEL project (see GPSVEL and overview) aims to archive GPS velocity solutions and include them in a global frame product of genuine use to the scientific community. The GPSVEL methods are designed to achieve these goals. The project requires input in the format of SINEX solutions as well as feedback on the GPSVEL solutions.

Please submit SINEX solutions to Lou Estey (louunavco.org)after first viewing the preliminary guidelines for the SINEX format and GPSVEL submissions. Any questions and feedback on the GPSVEL solutions should be directed to David Lavallee (D.A.Lavalleenewcastle.ac.uk).

The attachment method allows the GPSVEL solutions to be modular since regional solutions are not allowed to alter the global frame solution. Each GPSVEL version represents a complete global solution but is separated into various sub sections.

Each GPSVEL release will generally include:

• Global core solution (SINEX and GMT)
• Site information (Catalogue SINEX)
• Estimated Offsets information including suspected causes
• Regional solutions (SINEX and GMT)
• As much site and offset information as possible

Full site information will be included in the core solution SINEX files but will also be available in smaller "catalogue" SINEX viewable as txt. Offset information is included since it is essential for user quality assessment. An offset description file and data exclusion file have been designed to explain the need for offsets/exclusions in terms of equipment changes and seismic activity etc. Users are also encouraged to examine the SOLUTION/EPOCHS portion of the solution SINEX for the time span of data from which individual velocities were estimated. The regional solutions in their original submitted frame will be included in the UNAVCO GPS Site Motion Vector/Crustal Velocity Archive.

Please direct any feedback regarding the solutions to David Lavallee (D.A.Lavalleenewcastle.ac.uk).

GPSVEL 0.0

GPSVEL 0.1

The GPSVEL 0.1 solutions consists of a global solution with attached solutions for the AUS, EUR and SIR IGS RNAACs.

GPSVEL 0.2

The GPSVEL 0.2 velocity solution consists of a slightly improved version of GPSVEL 0.1 (0.2_core) and an attached solution for the Central Greece network Campaigns 1989-1997. The original solution [Clarke et al., 1998] is in a CG54 fixed frame and is available in the UNAVCO GPS Site Motion Vector/Crustal Velocity Archive.

There is no site overlap between the Central Greece network and the global component of GPSVEL 0.2. The solution is put into GPSVEL indirectly via ITRF 2000 (the current frame of GPSVEL). The network is translated using the ITRF 2000 velocity of the SLR site 7515 (Domes 12602M002) which is co-located with CG54. The procedure is described by Lavallee et al. [2001].

GPSVEL 1.0 - Most recent

The GPSVEL 1.0 velocity solution consists of all of GPSVEL 0.2, plus a regional solution for the Western US cordillera from Rick Bennett.

References

P. J. Clarke, R. R. Davies, P. C. England, B. Parsons, H. Billiris, D. Paradissis, G. Veis, P. A. Cross, P. H. Denys, V. Ashkenazi, R. Bingley, H.-G. Kahle, M.-V. Muller and P. Briole, Crustal strain in central Greece from repeated GPS measurements in the interval 1989-1997, Geophysical Journal International, 135, 195-214, 1998.

D. Lavallee, G. Blewitt, P. L. Clarke, K. Nurotdinov, W. E. Holt, C. Kreemer, C. M. Meertens, W. S. Shiver, S. Stein, S. Zerbini, L. Bastos, and H.-G. Kahle, GPSVEL Project: Towards a Dense Global GPS Velocity Field, Proceedings of the International Association of Geodesy Scientific Assembly, Budapest, 2-7 September 2001.    [PDF (421 kb)]

R. A. Bennett, J. L. Davis, J. E. Normandeau, and B. P. Wernicke, Space Geodetic Measurements of Plate Boundary Deformation in the Western U.S Cordillera, Plate Boundary Zones, American Geophysical Union Geophysical Monograph, 2001.

Last modified Friday, 21-Jul-2006 18:28:00 MDT

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