GIS & History of Mapping in Malaya (lecture notes circa 2009)
(GIS) & History of
Mapping in Malaya
Dr Azmi Mohd Tamil
Universiti Kebangsaan Malaysia
(National University of Malaysia)
Global Positioning System
What is GIS?
A computer system for capturing,
storing, checking, integrating,
manipulating, analysing and
displaying data related to
position on a surface.
AGI GIS Dictionary
GIS (Geographic Information System)
• Geographic Maps
• Information Database
• System Hardware, Software, Data,
GIS combines the intuitive visual clarity of a map together with
the information structuring, searching and analysing power of a
Layers for GIS
Other Thematic Data
Framework or Core Data
ID Name Pop_90 MMR
1 … 1897 4.5
2 … 2345 5.6
3 … 1293 1.2
4 … 560 6.7
480 000 494 500
Spatial Data Linked With Tabulated Data
GIS in Health
• Possible applications include mapping the
health of populations, identifying patterns
of disease transmission, and locating foci of
risk. Geographical methods can also be
applied in health administration and health
Early Use of GIS in Health
• In 1854 Dr. John Snow was able to pinpoint a cause of cholera outbreak In London
by the following:
“…He went to the Register of Deaths and got details of all the deaths from cholera
in the Golden Square, Berwick St and St Anne's, Soho, districts and plotted the
distribution of deaths in London on a map. He determined that an unusually high
number of deaths were taking place near a water pump on Broad Street. Snow's
findings led him to petition the local authorities to remove the pump's handle. This
was done and the number of cholera deaths was dramatically reduced…”
• The work of Doctor Snow stands out as one of the most famous and earliest cases
of geography and maps being utilized to understand the spread of a disease.
Early use of GIS in Health ;-)
• Outbreak of Cholera in London, 1854
• Spot map of the cases by John Snow
Measuring Spatial Data
GPSr – How does it work?
How accurate is it?
What is Global Positioning
System (GPS) ?
A very precise positioning system
• Developed and maintained by the
US Department of Defense (DOD)
• Satellite Based
* 24 satellites
* 20,200 km high orbit
Segments of GPS
1. Space Segment
of 24 satellites
How GPS Works ………
Uses measurements from 4+ satellites
Distance = travel time x speed of light
Determining GPS Position
• Suppose the distance from
Satellite A to our position is
• At this point we could be located
anywhere on the specified sphere
• Next, let us take another measurement
from a second satellite, Satellite BSatellite B
• Now our position is narrowed down to the
intersection of theses two sphere
Determining GPS Position
• Taking another measurement
from a 3rd satellite narrows our
position down even further, to
the two points
• So by ranging from 3 satellites we can
narrow our position to just two points in space
• These points are located where
the 3rd sphere cuts through the
the intersection of first two spheres
How do we decide which one is our
• We could make a 4th measurement
from another satellite to determine
the true point
• However, GPS receivers use a 4th satellite to precisely
locate our position
• We can eliminate one of the two
points that gives a ridiculous
• The ridiculous point may be too
far from the earth
• GPS: uses satellites to pinpoint the location
of receivers on earth. Handheld Navigation
How accurate is GPS?
Depends on some variables
• Design of receiver
• Relative positions of satellites,
technically known as PDOP (Position
dilution of precision)
• Time spent on measurement
Possible Source of Inaccuracies
• Satellite clocks (atomic)
• Atmospheric delays
• Receiver clocks (time
receiving good signal
GPS Error Sources
Receiver Clock Error
Satellite Clock Error including
Satellite Orbit Error
• When GPS signals arrive at the receiver
having traveled different paths
What is a PDOP?
• Position Dilution of Precision
Good PDOP Poor PDOP
SNR (signal-to-noise ratio)
• SNR determines the signal strength
relative to noise
• GPS position is degraded if the SNR of
one or more satellites in the
constellation falls below certain range
How Accurate is the Spatial Data?
• If we want sub-meter accuracy, then we would
have to use specialised GPSr surveying equipment
– DGPS (Differential GPS) - higher accuracy in terms of position. It
gets differential data live from a ground base station (Kuantan) and
compare them with the actual current position, using some
algorithm to get a better accuracy. Additional hardware required
and not available for Garmin GPSr.
– MyRTKnet - a nation-wide GPS network and system infrastructure
developed for GPS users to provide RTK and DGPS services with
unmatched accuracy. A wide-area satellite based service, the
broadcast My RTKnet corrections can be obtained anywhere in
Malaysia using a custom-built MyRTKnet GPS receiver.
– P-DGPS (Post-Processing Differential GPS) works the same way,
but not in real time. You would store your data elsewhere (storage
card, PPC on Notebook), then compare them with data registered
by a nearby MASS station at the same time you recorded yours.
This recalculation would give you a below 1 meter accuracy.
• Instead we will use a medium cost GPSr with
SIRFstar III chip which give us an accuracy of
within 3 meters or less (USD540)
• It has a horizontal position accuracy of less than
2.5m. Supports multiple reference frequencies.
Also supports SiRFDRive dead reckoning
technology for enhanced positioning accuracy and
How Accurate is the Spatial Data?
To reduce inaccuracy, the spatial measurement should be;
• Taken with a SIRFstarIII GPSr such as Garmin
• GPSr properly configured – i.e. Map Datum = WGS84
for own map, or Kertau 48 if using JUPEM maps.
• For mapping;
– Using an external antenna
– Tracking interval on GPSr set to every 1 second
– done using active log tracks only (ie. not using the tracks that
are saved to the GPSr)
History of Mapping
• The first attempt at triangulation survey was made in Penang in 1832
by Lieutenant Woore of the Royal Navy.
• In 1885, H.G. Deanne, a contract surveyor from Ceylon, was
appointed by the Public Works Department, Perak, to carry out the
Trigonometrical survey of Perak. He measured the 4.6 mile Larut
baseline and carried out astronomical determinations for latitude and
azimuth near Taiping.
• This Trigonometrical Survey in Perak together with the Penang and
Province Wellesley triangulations and Malacca Triangulation (1886-
1888), laid the foundation of the existing control framework. These
foundations were still primitive, progress was frequently sporadic and
much of the work was found to be substandard. However, by the end
of 1901, the Major Triangulation of Perak and Selangor had been
completed and work had been in progress in Negeri Sembilan since
1899. This period also witnessed the commencement of
trigonometrical surveys in various parts of the country.
MRT48 & MRT68
• However, the quality of the early works were so
inconsistent that it was decided to re-observe the principal
triangles of the general triangulation with the object of
bringing the work up to modern standards.
• This triangulation scheme in Peninsular Malaysia was
known as the Primary or Repsold Triangulation which was
completed in 1916.
• In 1948, it was replaced by a new system known as the
Malayan Revised Triangulation (MRT). This was followed
by a lengthy process of additional measurements and
recomputation until 1968.
• As a result, this system is then referred to as MRT68. On
the other hand, the geodetic network used in Borneo is
called the Borneo Triangulation (BT68).
American Mapping Service
• In 1965, the American Mapping Service
(AMS) carried out an internal re-adjustment
of the MRT in order to connect it to the
South East Asia Datum (SEA Datum). In
1965, AMS re-adjusted the MRT data in the
South East Asia Datum using three
triangulation points in Thailand held fixed.
World Geodetic System 1972
• In 1978, the British Army Survey carried out a
Doppler campaign in Peninsular Malaysia, Sabah
and Sarawak in order to connect the local network
to the World Geodetic System 1972 (WGS 72).
The network consists of 5 points of the MRT and
5 points of BT68. The given accuracy is of the
order of three metres. However, the observations
were never used for any re-adjustment of the MRT
• In November 1993, a group from the Squadron of Technical Royal Engineers
(STRE) of the United Kingdom observed with TRIMBLE GPS L1/L2
receivers on 5 existing Doppler points and 9 new GPS stations in Peninsular
• In addition to that, 7 existing Doppler points and 4 old trigonometric stations
were also observed in Sabah and Sarawak.
• The aim is to establish better transformation parameters from Doppler to
WGS84 for the region and to connect Peninsular Malaysia to Sabah and
• In Dec, 1993, the GPS observations were successfully completed and
computations and analysis were subsequently conducted based on the WGS84
• Results of STRE adjustments show that the absolute accuracy of WGS84
coordinates is at the 1m level for the X,Y and Z axes respectively.
• This project which was initiated in 1994 and was completed in 1997, was to
study the plate motion and crust deformation in the region of the South and
South East Asia.
• GPS campaigns were carried out in December 1994 and April 1996 to study
such motions. This is followed by a GEODYSSEA Symposium in April 1997
in which results of the campaign were tabled and discussed.
• Even though the GEODYSSEA project was officially terminated in 1997, the
studies in the geodynamics of the region were still pursued with a GPS
campaign carried out in October 1998. The purpose of the endeavour was to
further gauge and confirm the plate movements in the region as initiated by the
• With the availability of such data, a time series dynamics of the region could
be collected and studied. From the two GPS campaigns of 1994 and 1997, a
zero order network had also been able to be set-up in Malaysia with
coordinates referring to ITRF94 and ITRF96 and with an absolute accuracy of
better than ± 3cm.
Kertau 48 & WGS84
• A geodetic datum is a reference model of the Earth,
designed to fit all or part of the geoid
• Datums provide the surface to which ground control
measurements are referred, and are used as reference
systems for navigation, surveying and mapping
• A datum is defined by a
specific ellipsoid and a unique
point of origin
Name Ellipsoid Origin
WGS 84 WGS 84 Earth’s centre of mass
NAD 27 Clarke
Meades Ranch, KS
NAD 83 GRS 80 Earth’s center of mass
North American Datum
South American Datum
International Arc Datum
Most widely used local Datum/Ellipsoid pairs
So WGS 84 is no longer a
How about Kertau 48?
History of M’sian Map Datum
• In the past, before the advent of GPSr and the
GPS satellites, mappers determined the
coordinates of an origin as best as they could,
then they measured the distances and the
bearings of other places, using the origin as the
Even with the best possible method that they
have, the coordinates of the origin may be
• For example the origin
for our national map
datum used to be
• Why Bukit Kertau?
Although it is not the
highest point (only
269.3m), it is centrally
located in Peninsular
Kertau 1948 or MRT
77 positions of Repsold
orientation at Kertau,
scale very few.
Origin at Kertau (ξ=0, η=0, N=0)
Kertau Measurement Disparity
N 3o 27'
E 102o 37'
1948 N 3o 27'
E 102o 37'
MRT68 1965 N 3° 27 '
E 102o 37'
WGS 84 STRE
ITRF 94 GEOD
E 102o 37'
• 1 longitudinal degree is roughly 111.324
km. Since 1913, Kertau has "moved"
• Peninsular maps using MRT48 has to be
"moved" (corrected) almost 200m to the
North-West to correct the coordinates to
conform with WGS84.
10 coordinate systems in Malaysia
1. Old Cassini-Soldner for Peninsular Malaysia (E, N)
2. Old Rectified Skew Orthomorphic for Peninsular Malaysia (E, N)
3. Old Rectified Skew Orthomorphic for East Malaysia (E, N)
4. Malayan Revised Triangulation (f, l, h)
5. Peninsular Malaysia Primary GPS Network (f, l, h and X, Y, Z)
6. East Malaysia Primary GPS Network (f, l, h and X, Y, Z)
7. Geocentric Datum of Malaysia (f, l, h and X, Y, Z)
8. New Cassini-Soldner for Peninsular Malaysia (E, N)
9. New Rectified Skew Orthomorphic for Peninsular Malaysia (E, N)
10. New Rectified Skew Orthomorphic for East Malaysia (E, N)
Most Maps Are MRT68
• From MRT68, map
projections were done
using Rectified Skew
• For cadastres, Cassini
Soldner were used.
• The existing Cassini
used for cadastral
application in the
Peninsular is based on
local MRT datum.
9 Peninsular State Cassini-coordinate systems
• The latitude and longitude of the origins
are not referred to a single triangulation
system but 9!
Gunung Perak for Perlis & Kedah
Fort Cornwallis for Penang & Province
Hijau Larut for Perak
Bukit Asa for Selangor/Kuala Lumpur
Gun Hill for Melaka & N. Sembilan
Gunung Belumut for Johor
Gunung Sinyum for Pahang (not
Gajah Trom for Terengganu
Bukit Panau for Kelantan
• That is why we have to ask what is the
datum of the map being used (i.e.
MRT48/MRT68) since the conversion
of the coordinates of the GPSr differ
according to the datum.
• Since then, we have progressed to PMGGN
(WGS84) in 1989. Now in 2003, JUPEM
have adopted GDM2000 (GRS80).
• The introduction of GDM2000 will have a
significant effect on the topographical
mapping products : the coordinates (shift)
of points by up to approximately 200 meters
in northeasterly and northwesterly
directions for Peninsular and East Malaysia,
• With the adoption of GDM2000, the
existing Cassini projection system used for
cadastral application will be converted to
Geocentric Cassini Coordinate System.
• For topographical mapping application in
Malaysia, conversion will be done from
RSO & Borneo RSO into Geocentric RSO
9 New Origins
• To assist in the process, nine new origins (9 primary GPS
stations) are selected in the vicinity of the old origins with
their coordinates accurately defined in the GDM2000.
The new origins are;
GP58 Institut Haiwan,Kluang
GP12 Lubuk China, Melaka
GP31 Kuala Mai, Jerantut
MASS Station Wisma Tanah, Jalan Semarak, Kuala Lumpur
P253 Kg. Matang, Hulu Terenganu
P314 TLDM Georgetown
TG35 Gunung Perak, Kuala Muda
TG26 Gunung Larut Hiijau, Taiping
P222 Ulu Kelantan
• Ask what is the datum of the map being
used (i.e. MRT48/MRT68) since the
conversion of the coordinates of the GPSr
differ according to the datum.
• Otherwise we may end up 193 meter away
from the correct position.