Volume 6 – Geotechnical Manual, Site Investigation and Engineering ...

Chapter 2 MAP PROJECTION
2.2 MAP PROJECTION MALAYSIA
2.2.1 Rectified Skew Orthomorphic (RSO) Projection
Rectified Skew Orthomorphic Projection has been adopted for the Topographic Maps produced by
the Department of Survey and Mapping Malaysia. The result of this projection is the RSO Grid
Coordinates. The Datum for this projection is KERTAU (Bukit Kertau Pahang). RSO projection was
selected to suit the shape of Peninsular Malaysia. The limits of the projection are mainland
Peninsular Malaysia and the close lying offshore islands. This RSO projection cannot be extended to
include islands in the South China Sea, nor the East Malaysia states of Sabah and Sarawak. The East
Malaysia states are covered by a second RSO projection. The Datum for this projection for the land
below the wind is TIMBALAI (Timbalai Labuan).
The mathematical theory on which the projection is based is found in the article “The Orthomorphic
Projection of the Spheroid” by Brigadier M. Hotine CBE, published in the “Empire Survey Review” Vols
VIII and IX Nos 62-65, particularly para 19 E.S.R. No. 64 of April 1947.
2.2.2 Cassini Soldner Projection
Figure 2.2 RSO Grid Projection on Topographic Map
This projection was used extensively in Great Britain in the 19 th Century where mapping was done by
the respective counties (Majlis Perbandaran) whose areas are small. However it is not suitable for
mapping of a nation as the projection is subjected to distortion of scales which increase progressively
for areas whose distances increase from the central meridian of the ellipsoid. Similarly, the Cassini
Soldner projection used in Peninsular Malaysia is on a state by state basis (except for the large state
of Pahang which has 4 zones) by defining a central meridian and origin of projection for each of the
states.
Computation of cadastral coordinates for land title survey in Peninsular Malaysia based on the cassini
soldner projection is very simple. It is based on the concept of selecting a fixed meridian and a point
2-2 March 2009