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

Chapter 3 TYPES OF SURVEY
3.2.5 Basic Control (Geodetic) Surveys
Basic control survey provides positions, horizontal and or vertical, of geographic points on a terrain in
a control framework to which supplementary surveys are adjusted. Most of these basic controls are
limited to fit national mapping requirements and cannot be applied internationally. In Malaysia,
these points are contained in two control network based on two local geodetic datum namely the
Malayan Revised Triangulation (MRT) network for Peninsular Malaysia (West Malaysia) and the
Borneo Triangulation 1968 (BT68) network for Sabah and Sarawak (East Malaysia).
However, with the advent of new technologies such as the Global Positioning System (GPS) and
Unified Geographic Information System (GIS) over large areas, the existing MRT and BT68 network
have become outdated. A new Geocentric Datum of Malaysia (GDM2000) which fits into the global
geodetic framework has been introduced to eventually replace the MRT and BT68. The GDM2000
datum contains the Peninsular Malaysia Primary Geodetic Network (PMPGN) of permanent GPS
Stations established in 1998 for geodetic and scientific purposes. A similar East Malaysia Primary
Geodetic Network (EMPGN) is being established.
3.2.6 Satellite Surveys
Satellite surveys employ the use of artificial earth satellites as a means of extending geodetic control
systems. These positioning of points on the ground in a geodetic control system are being conducted
using artificial earth satellites in the Global Positioning System (GPS) for long line surveys where the
distance between stations is a few hundred kilometers apart. They are used for conducting
worldwide surveys for intercontinental, inter-datum and inter-island geodetic ties. Topographic and
basic control surveys are frequently conducted with satellite surveys. Special project instructions are
written to detail methods, techniques, equipment and procedures to be used in these surveys.
3.2.7 Hydrographic Surveys
A survey made in relation to any considerable body of water, such as a strip of part of the sea along
the coast, a bay, harbour, lake or river for the purpose of determination of channel depths for
navigation, location of rocks, sand bars, and in the case of rivers for flood mitigation control, hydroelectric
power generation, navigation of boats, water supply and water storage.
3.2.8 Land Surveys
Land surveying embraces survey operations to locate and monument the boundaries of a property to
meet the requirement of Land Laws relating to land and land tenure in the National Land Code (Act
56 of 1965). In the case where alienated land is acquired for construction works such as flood
mitigation projects land survey has to be conducted to meet the requirement of the Land Acquisition
Act. Land survey is commonly referred to as Cadastral Survey.
3.2.9 Engineering Surveys
It is executed for the purpose of obtaining information which is essential for planning an engineering
project or proposed development and estimating its cost. The survey information may, in part, be in
the form of an engineering survey map.
3-2 March 2009