OSG SA Convention for the Australian Height Datum (AHD) Survey Control Network - Permanent Survey Marks

OFFICE OF THE SURVEYOR-GENERAL

SA Convention for the Australian Height Datum (AHD) Survey Control Network

Since the positional uncertainty (PU) is not available for AHD height, ‘order’ remains relevant for describing the quality of the heights.

The following table indicates the vertical accuracies of the orders and the techniques used to derive the heights quoted in the survey mark reports.

Precision

Accuracy

Order

Method

12√K (mm)

+/-0.10m

3

3rd order levelling

18√K (mm)

+/-0.15m

4

4th order levelling

0.1m

+/-0.25m

5

GNSS (Static, Rapid Static & Kinematic) adjusted to the local levelling control network

0.2m

+/-0.50m

6

GNSS (CORS RTK / RTK / PPP / AUSPOS) not adjusted to the local levelling control network

0.5m

+/-1.00m

7

Doppler / Inertial / Photogrammetry / Vertical Angles / Other

NA

NA

9

Scaled from topographics map

PSM coordinates provided by industry that have a PU but no height will be assigned a height by the Office of the Surveyor-General. The height will be derived by scaling topographic maps to allow LSSA survey examination to calculate a combined scale factor and compare lodged survey plan data with PSM coordinates. These heights will be stored in the survey mark database as order 9 with the method ‘scaled’ but will not be displayed on the SAPPA or SAILIS survey mark reports. All other AHD heights (order 7 or better) will be displayed with three (3) decimal places irrespective of their derivation and accuracy.

We acknowledge and respect Aboriginal peoples as the state's first peoples and nations, and recognise them as traditional owners and occupants of land and waters in South Australia. Further, we acknowledge that the spiritual, social, cultural and economic practices of Aboriginal peoples come from their traditional lands and waters, that they maintain their cultural and heritage beliefs, languages and laws which are of ongoing importance, and that they have made and continue to make a unique and irreplaceable contribution to the state. We acknowledge that Aboriginal peoples have endured past injustice and dispossession of their traditional lands and waters.