Geoscience Reference
In-Depth Information
The Geocentric Datum of Malaysia:
Preliminary Assessment and Implications
Noor Suryati Mohd Shariff, Tajul Ariffin Musa, Kamaludin Omar
and Rusli Othman
Abstract The reliability of the national geocentric datum must be assessed
regularly to maintain high geospatial accuracy in terms of consistency with respect
to the global datum, i.e. International Terrestrial Reference Frame (ITRF). This
can be accomplished by considering the spatial and temporal variations caused by
plate tectonic movements. This study aims to assess the reliability of Geocentric
Datum of Malaysia (GDM2000) by analysing the datum shifts via the displace-
ments of the Malaysian Real Time Kinematic Network (MyRTKnet) stations
caused by tectonic movements as well as the displacements induced by reference
frame effects. A significant land displacement up to 17 and 30 cm in north and east
components were found respectively, due to local active fault and the cumulative
plate tectonic motion. The implications of a non-geocentric datum are also
discussed.
Keywords Geocentric datum
Reference frame
Plate tectonic
1 Introduction
The geocentric datum represents a best-fit ellipsoid where its origin and orientation
is with respect to the Earth-centred Earth-fixed (ECEF) coordinate system.
Therefore, the geocentric datum has the following descriptions; (1) its origin
coincides with the Earth's centre of mass, (2) the orientation of the X-axis is
pointing towards the mean Greenwich meridian, (3) the Z-axis is parallel to the
rotation axis of the earth, (4) the Y-axis completes the right-handed system, and
