Survey Reference System
SURVEY CONTROL NETWORK
SLA has established the land survey control network as the infrastructure to support survey work conducted by all Registered Surveyors. This allows all land lots in Singapore to be geographically linked to each other and to the whole of Singapore. We maintain 2 types of survey control, namely the Horizontal Control Network and Vertical Control Network.
HORIZONTAL CONTROL NETWORK
There are two categories of horizontal control: Primary and Secondary control network. As a whole, they are known as the Integrated Survey Network (ISN).
The primary control network consists of about 39 points that are strategically located in Singapore, most of which are on top of HDB flats, to cover the entire area of the island.
The secondary control network comprises of more than 5,000 points, which are mostly found on the ground along major roads for easy access.
VERTICAL CONTROL NETWORK
The vertical control network consists of physical points on the ground known as Precise Levelling Benchmarks (PLBM). There are about 400 PLBMs located at 1 km intervals along major roads. PLBM information is used to determine heights of locations in Singapore.
You can gain access to horizontal and vertical control network information here
POSITIONING WITH GLOBAL NAVIGATION SATELLITE SYSTEM (GNSS)
SiReNT is used to enable high precision and accuracy applications that include surveying and mapping, self-mobility vehicles development, construction automation, geodata capturing and asset management, amongst many others.
For more information on SiReNT, please visit the SiReNT website at www.sla.gov.sg/sirent.