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

Chapter 4 REFERENCES ON GEOMATICS AND LAND SURVEY SERVICES
a. Connection to Survey Department Horizontal Datum which provides scale, position and
azimuth control for establishing boundary marks shown on land title survey or cadastral
survey plans to meet issue document of titles to land based on the Cassini Soldner
projection.
b. And then the proposed or existing routes or alignment, identified by the Department of
Drainage and Irrigation. Issue to be considered here are land with various category of titles
and ownership which have to be obtained from the Cadastral Division Department of Survey
and Mapping, the Land Office and sometimes direct objection from the affected land owner
himself.
4.4 HEIGHT (VERTICAL) CONTROL AND CONNECTION (JADUAL 2001 ITEM 1.6).
Height controls and connection to determine the spot level of a feature includes:
a. Connection to Survey and Mapping Department Bench Marks (BM) based on the Land Survey
Datum (LSD) and now known as the National Vertical Geodetic Datum (NGVD) which is
located at a tide gauge station sited in Port Klang, Selangor
b. Connection to the CHART DATUM which is traditionally referred to as the Admirably Chart
Datum. These datums are located at Tidal Stations, mainly jetties or ports along the coast.
Appendix 3A-1 attached contains a list of the existing Tidal Stations.
c. Occasionally connection to both the LSD and the Admirably Chart Datum has to be related
for marine navigation structures such as a fishing jetty or port. An example of this is
depicted in the diagram below which shows the Chart Datum is 1.7m below the Land Survey
Datum.
d. And then along the proposed or existing routes or alignment identified by the Drainage and
Irrigation Department
4-2 March 2009