Assessing Global Geodetic Datum between International Terrestrial Reference Frame 2014 and World Geodetic System 1984 using GPS Observation
Keywords:Geodetic Datum, Reference Frame, Accuracy, Positional Discrepancy
Nowadays, the countries develop their national modern geocentric datum based on International Terrestrial Reference Frame (ITRF) by tying the Continuous Operating Reference System (CORS) stations to ITRF. At the same time, WGS84 is widely used for positioning and data processing-related applications. It has been assumed that the WGS84 new realisation coincides with ITRF at the 10-centimetre level; thus, the transformation parameters between ITRF and WGS84 are not considered. The reference epoch of WGS84 is often not mentioned in most studies, and this issue is claimed to be insignificant. Thus, this study aims to assess the global geodetic datum - International Terrestrial Reference Frame 2014 (ITRF2014) and World Geodetic System 1984 (G1762) using GPS observation in Peninsular Malaysia. Firstly, the horizontal and vertical components at collocated stations of IGS that give ITRF2014 and WGS84 (G1762) were obtained and compared. Secondly, the daily solution data was checked, followed by Root Mean Square Daily Repeatability checking. Finally, the final coordinate solution evaluated the positional difference at selected MyRTKnet station coordinates between ITRF2014 and WGS84 (G1762) in Peninsular Malaysia. The positional discrepancy for the horizontal component (northing and easting) is at -15.71 and 48.66 centimetres, respectively, while the vertical component (ellipsoidal height) is at 3.88 centimetres level. Overall, this study can provide an insight to the users about the global geodetic datum and eventually a more transparent and improved accuracy on the datum transformation module for geodetic-related applications.