Geodetic Survey

Geodetic Services

In 1993 the geodetic control network of Sri Lanka was upgraded by using precise baselines meassured using global positioning system. The transformation parameter were computed from the local datum called Everest 1830 to global datum called WGS84. Hence Global Positioning System receivers can be used to obtain the national grid system centimeter level accuracy.

Sri Lanka Continuously Operating Reference Station Network (SLCORSnet) comprises of physical GNSS reference stations at remote designated locations that transmit the collected GNSS raw data live to the Control Centre based in Colombo at the Survey Generals Office. This raw data is processed using a GNSS network processing software housed at the Control Centre which then will be transmitted to the users in the field over the internet based on their geographic location in the form of RTCM corrections. Online delivery of RINEX raw data and online post-processing services are provided as real-time web services from the SLCORSnet. Once, registered under SLCORSnet and once you have purchased these services, you are allowed to use these services freely during the subscription period.

Issue of Geodetic Information to Licensed Surveyors and Outside the Department

Following type of geodetic information will be issued from the Geodetic Survey Units at SGO, Colombo & ISM, Diyatalawa, at the rates given below.

  • Bench mark information of primary and Secondary level lines. Only the ‘C” type bench mark will be issued unless the survey is supervised by the dept.
  • All triangulation points, coordinates and route sketches.
  • GNSS Primary Control points, coordinates and sketches.
  • First Order traverse control point, coordinates and sketches.
  • GNSS data.
Type of Information Rate (Rs.) Collection possible from
BM height with the diagram 260.00 SGO/ISM
Coordinates of 1ndorder and 2nd order EDM traverse control points with diagrams 260.00 SGO/ISM
Coordinates of a GPS primary control point with diagrams 500.00 SGO/ISM
Coordinates of Trigonometrical station with observed bearings and descriptions 320.00 ISM
GNSS data from SLCORSnet 1 Day (24 Hours) 2,000.00 SGO
GNSS data from SLCORSnet 7 Days (1 week) 10,000 SGO
GNSS data from SLCORSnet 30 Days (1 Month) 30,000 SGO
GNSS data from SLCORSnet 365 Days (1 Year) 360,000.00 SGO
Base data of SLCORSnet 6.00 am – 6.00 pm per station per day 600.00 SGO

Note:- All applicable tax to be added to above rates

Certification of GNSS Tertiary level Control Points, Traverse Control Points& Level lines (BM) done by Private Sector Surveyors.

Other services are available in Geodetic Survey Unit.

  • Consultancy Services.
  • Establishing of (GPS) control points.
  • Precise Levelling.
  • Conducting Special Geodetic Survey Projects