Geodetic survey mark information

The geodetic network (datum) is the foundation of all spatial data in Western Australia. Landgate maintains this network and provides access to the geodetic mark information to meet our state’s economic, social, and environmental needs. The online geodetic database stores the details of approximately 64 000 geodetic survey marks and includes the Christmas and Cocos (Keeling) islands. Geodetic mark report is available for all standard survey marks (SSMs), bench marks (BMs) and continuously operating reference stations (CORS).

Geodetic mark report can be accessed by any of the following five options

  1. Map Viewer Plus - geodetic marks can be accessed via Map Viewer Plus by selecting Geodetic from the layer list. (Map Viewer Plus will eventually replace Locate below). Map Viewer Plus works on most popular devices including mobile devices and has search options available to enable the location of marks. Select Search then Geodetic Marks from the drop down menu. For details download this Map Viewer Plus - How to guide [PDF 1.0MB] or watch this how to video. You can contribute to keeping the geodetic database up to date by providing geodetic mark status report. See below for more details.
  2. Locate - the geodetic layer in Locate provides full information about geodetic survey marks via a popup and links to the Geodetic On Line Access (GOLA) report and station access diagram. (Locate - How to guide) [PDF 0.7MB].  Further information about Locate can be found here.
  3. - the open data website provides the geodetic data in the form of a downloadable Shapefile or WMS access to the Landgate geodetic layer.
  4. My Landgate / Survey Channel / Map Viewer - use my Landgate Map viewer to interactively select and retrieve the GOLA report and station access diagram. (How to guide) [PDF 0.5MB]
  5. Download a Google Earth KML file [KML 4KB] containing a link to Western Australia’s geodetic marks. Download the file and open the link. The current KML file will be downloaded to Google Earth. Be patient while it loads the file. Zoom to your area of interest and view geodetic marks near that location. Selecting a geodetic mark symbol opens a popup with mark attributes including coordinates, height, accuracy and status. The popup also contains a link to a more detailed GOLA station report. Additional links in the GOLA report can be used to download information including a graphic summary. For details watch this how to video.

Geodetic mark report information

  • Horizontal datum - geographic coordinates in GDA2020 and GDA94, UTM projected coordinates in MGA2020 and MGA94 and project grids where available.  Other historic datums are available on request.
    • Note - Currently GDA2020 is the primary horizontal datum and the only datum being maintained and GDA94 is now considered as a historic datum.
    • GDA2020 is a static datum.
    • GDA2020 Technical Manual [PDF 3.08MB].
    • GDA94 Technical Manual [PDF 2.18].
  • Vertical datum - heights in AHD71, Christmas and Cocos (Keeling) height datums.
    • For additional information about AHD71 modification around Perth please refer to this document [PDF 0.9MB] (Metro and Buffer Zones can be downloaded here [KML 0.5MB]).
    • GDA2020 ellipsoidal heights provided on GNSS surveyed marks.
  • Geoid (N) values for AUSGeoid2020 and AUSGeoid09.
  • Positional uncertainty (horizontal and vertical), relative horizontal accuracy, and error ellipses.
  • Survey method.
  • Reference mark information.
  • Physical status and date of the mark (and reference mark).
  • Cadastral connection, field books, and notes.
  • A station summary access diagram

Geodetic mark status report

When a geodetic mark is used (for any reason other than a cadastral survey which requires a field book to be lodged) Map Viewer Plus should be used to report feedback about the condition of the mark. This information is used to keep the geodetic database up to date for the benefit of all geodetic mark users. As an added incentive all geodetic mark status updates and impending works notifications automatically go into a monthly prize draw of a $100 voucher to major retailers. You can also report provide mark feedback via geodetic mark status report form [PDF 0.6MB] or alternatively you can contact a member of the survey services team at or phone +61 (0)8 9273 7111.

Geodetic mark impending works notification

Where any geodetic mark is at risk of being damaged or destroyed, Landgate must be notified immediately to enable appropriate remedial action.The Geodetic mark impending works notification form [PDF 0.5MB] should be used in these circumstances or alternatively you can contact a member of the survey services team at or phone +61 (0)8 9273 7111.

Asbestos in geodetic mark hatch cover surrounds

A number of Landgate's early geodetic mark hatch cover surrounds were moulded using asbestos cement. Please read this asbestos notification before using geodetic marks [PDF 0.3MB].

Geodetic news

Subscribe to this quarterly Geodetic Newsletter to stay up to date with the latest information from Landgate's Survey Services department.

Need help?

For more information contact a member of the Survey Services team on +61 (0)8 9273 7111 or email

This page was last updated on: 21 Jun 2019