Towards a Semi-Kinematic Datum for Egypt


Since 1990, positioning technology has undergone a dramatic improvement in terms of accuracy and accessibility. Prior to 1990, national geodetic datums were considered to be static with fixed coordinates assigned to the datum origin by convention. Datum coordinates were dynamic only as a consequence of re-observation and re-adjustment, or localized disturbance. This strategy has been suitable for terrestrial surveys within stable continental areas. The accessibility of Precise Point Positioning “PPP” is now widespread with the provision of free online processing facilities by various geodetic agencies. Such ready accessibility to a global datum has serious implication for this technology with static geocentric datums. The Geocentric Datum of Egypt (ITRF1994 Epoch 1996 based on GPS Observation Campaign 1996), for example, is now offset by -42.0 to +32.0cm from the ITRF2008 Epoch 2015 due to the inexorable tectonic movements of the Nubian plate since the datum realization in 1996. Unless the local geocentric datums are kept in step with global terrestrial reference frames, discrepancies between the two will increase in magnitude over time and will become discernable, even using PPP. The PPP users nowadays are unaware of this datum offset and incorrectly assume that a coordinated datum monument is in error if there is found to be a disagreement greater than the level of accuracy of the positioning technique. In this study, to avoid the discrepancies between the applied datum and On-Line GNSS Services, a semi-kinematic datum and related deformation mode are proposed for Egypt. The result also confirmed that the PMM model was giving good performance for the other parts out of Egypt. The evaluation study shows the best performances for the Egyptian deformation model over the ITRF2008 PMM.

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Rabah, M. , Shaker, A. and Farhan, M. (2015) Towards a Semi-Kinematic Datum for Egypt. Positioning, 6, 49-60. doi: 10.4236/pos.2015.63006.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Scott, M. (1997) Results of Final Adjustment of New National Geodetic Network. Geodetic Advisor for the Egyptian Survey Authority.
[2] Boucher, C. and Altamimi, Z. (2001) ITRS, PZ-90 and WGS 84: Current Realizations and the Related Transformation Parameters. Journal of Geodesy, 75, 613-619.
[3] Altamimi, Z. (2002) Discussion on How to Express a Regional GPS Solution in the ITRF. Institute Geographique National (IGN), Ecole Nationale des Sciences Geographiques, Marne la Value Cedex.
[4] Dawson, J., and Woods, A. (2010) ITRF to GDA94 Coordinate Transformations. Journal of Applied Geodesy, 4, 189- 199.
[5] Altamimi, Z., Collilieux, X. and Metivier, L. (2011) ITRF2008: An Improved Solution of the International Terrestrial Reference Frame. Journal of Geodesy, 85, 457-473.
[6] Stanaway, R., Roberts, C. and Blick, G. (2012) Realization of a Semi-Kinematic Geodetic Datum Using an Absolute Deformation Model (ADM). School of Surveying and Spatial Information Systems, University of New South Wales, Sydney.
[7] Pearson, C., McCaffrey, R., Elliott, J. and Snay, R. (2010) HTDP 3.0: Software for Coping with the Coordinate Changes Associated with Crustal Motion. Journal of Surveying Engineering, 136, 80-90.
[8] Altamimi, Z., Métivier, L. and Collilieux, X. (2012) ITRF2008 Plate Motion Model. Journal of Geophysical Research, 117, B07402.
[9] Saleh, M. and Becker, M. (2013) A New Velocity Field from the Analysis of the Egyptian Permanent GPS Network (EPGN). Arabian Journal of Geosciences, 7, 4665-4682.
[10] Dow, J.M., Neilan, R.E. and Rizos, C. (2009) The International GNSS Service in a Changing Landscape of Global Navigation Satellite Systems. Journal of Geodesy, 83, 191-198.
[11] Stanaway, R. and Roberts, C. (2009) A Simplified Parameter Transformation Model from ITRF2005 to Any Static Geocentric Datum (e.g. GDA94). Proceedings from International Global Navigation Satellite Systems Society IGNSS Symposium 2009, Surfers Paradise, 1-3 December 2009.

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