Date post: | 19-Dec-2015 |
Category: |
Documents |
Upload: | alicia-booth |
View: | 234 times |
Download: | 4 times |
Coordinate Systems in Malaysia
History, Future and Somewhere in Between
For GMAT2700 Geodesy and Spatial Reference Frames
By Nor Yahaya
Malaysia
History of Malaysian DatumHistory of Malaysian Datum
• Starting with the geodetic datum - realized by establishing triangulation network.
Triangulation:
•Measurement of at least a baseline and angles•Basic principles:•If length of one side of a triangle is known and angles are accurately measured, the other two sides of the triangle can be measured
History of Malaysian DatumHistory of Malaysian Datum
• Old Triangulation Network for Peninsular Malaysia:
History of Malaysian Datum – Malayan Primary Triangulation
History of Malaysian Datum – Malayan Primary Triangulation
• Malayan Primary Triangulation– Primary Triangulation of Malaya (1913 – 1916)• Formed by the existing triangulation network• System was not unified through common adjustment• Resolved to one common system in 1948• Lat/ Long of the origin of Repsoid Triangulation (Kertau)
was decided to be altered.
History of Malaysian Datum – Malayan Primary Triangulation
History of Malaysian Datum – Malayan Primary Triangulation
• Malayan Revised Triangulation (MRT)• Used in Peninsular Malaysia since
1948• Consists of 77 geodetic stations, 240
primary stations, 837 secondary and 51 tertiary stations
• Adopted as a result of previous network re-computations + Primary Triangulation
• Reference ellipsoid – Modified Everest
• Origin – Kertau• Map projection – Rectified Skew
Orthomorphic (RSO)• Cadastral surveys projection –
Cassini Soldner
History of Malaysian Datum – Malayan Primary Triangulation
History of Malaysian Datum – Malayan Primary Triangulation
• Borneo Triangulation 1968 (BT68)• Geodetic network for Sabah and Sarawak• Results from the re-adjustment of the primary
control of East Malaysia• Origin – Bukit Timbalai, Labuan
Well suited for surveying of long
inter-station distances (ten kms – hundreds
kms)
Well suited for surveying of long
inter-station distances (ten kms – hundreds
kms)
Capable of 3D baseline
measurement
Capable of 3D baseline
measurement
All weather operationsAll weather operations
24/7 availability
24/7 availability
Globally applicableGlobally
applicable
Technology revolution
Needs Towards Geocentric Datum
GDM2000 – The Realization
MASS Network in Malaysia
Existing PMPGN and EMPGN
IGS Stations
GDM2000 – ImplicationsGDM2000 – Implications
GDM2000 – ImplicationsGDM2000 – Implications
• On Mapping– Change in coordinates ≈ 200m200m– Displacement:• 1:50000 4mm4mm on map• 1:10000 20mm20mm on map
– Change in gridsgrids and graticulesgraticules position– Change in coordinates of map features– Transformation process in mapping products will
be simplesimple
GDM2000 – ImplicationsGDM2000 – Implications
• On GPS Positioning– Currently is based on WGS84 coordinates– Not much difference:• GDM2000 is based on ITRF2000 epoch 00.0• WGS84 has been closely aligned to ITRF
– However will affect high precision absolute high precision absolute positioning
Coordinate System in Malaysia
References
• GDM2000 Technical Manual from Department of Surveying and Mapping Malaysia
• GMAT4900 lecture notes from C. Rizos, 2010