Towards the Implementation of Semi-Dynamic Datum for Malaysia

Abstract

A semi-dynamic datum provides positions with respect to time while taking into account the secular and non-secular deformations, making it the best approach to adapt with the dynamic processes of the earth. Malaysia, as yet, employs a static datum, i.e., GDM2000, at epoch 2000; though Malaysia has evidently been affected by seismic activity for the past decade. Therefore, this paper seeks to propose a design for implementing a semi-dynamic datum for Malaysia. Methodologically, GPS time series analyses are carried out to investigate the seismic activity of Malaysia, which essentially contributes to the proposed design of the semi-dynamic datum for Malaysia. The implications of implementing a semi-dynamic datum for Malaysia are discussed as well. The results indicate that Malaysia undergoes a complex deformation; whereby the earthquakes – primarily the 2004 Sumatra-Andaman, 2005 Nias and 2012 Northern Sumatra earthquakes – have affected the underlying secular velocities of Malaysia. Consequently, from this information, the proposed design, particularly the secular and non-secular deformation models, is described in detail. The proposed semi-dynamic datum comprises a transformation, temporal, and spatial module, and utilizes a bilinear interpolation method. Overall, this paper aims to contribute to the feasibility of a semi-dynamic datum approach for Malaysia.

The Implementation of Modern Geocentric Datum: A Review

“…The coordinates of the geodetic stations are remained to that reference epoch (Grant and Pearse, 1995). Thus, it only accurately reflects the actual position, connecting to the ITRF on a specific reference epoch (Shariff et al, 2017).…”

“…A study is conducted by Shariff et al, (2017) towards the implementation of semi-dynamic datum in Malaysia. It is based on single reference epoch whereby coordinates of the observation epoch are propagated to the reference epoch and able to propagate to any epoch with inclusion of deformation model.…”

“…However, the implementation of semi-dynamic datum needs the revision of cadastral database as well. Practically, this is difficult to be implemented in a region that has internal problems regarding to cadastral database like Malaysia (Shariff et al, 2017).…”

“…The global adoption of a geocentric datum is a main datum followed by the regional and national geocentric datum whereby the adoption of geocentric datum is particularly consistent with the International Terrestrial Reference System (ITRS). The ITRS is accomplished through the International Terrestrial Reference System (ITRF) which demonstrates the paramount accessible global geocentric datum (Shariff et al, 2017).…”

Investigating the National Digital Cadastral Database (Ndcdb) Data Handling Within Gis Applications

“…NDCDB is projected to GDM2000 or GDM2000 conducted in epoch 2006 and not GDM2000(2009) due to different reason and discrepancy of the GDM2000-based database (Shariff et al, 2017;Shariff et al, 2014) that may implicate legal concerns. On that note, it should be recognised that different map projection parameters of the NDCDB projection is inevitably to cause spatial displacement or Arc length distance difference of at least 13km as shown in Table 3.…”