An Electronic Distance Measuring (EDM) Baseline, located off Antill Street Watson, is available for use for calibrating EDM equipment.
As a Verifying Authority for length, the ACT Surveyor-General re-verifies the Watson EDM Baseline annually in accordance with the provisions of the:
About the Baseline
The Watson EDM Baseline consists of 11 forced-centring pillars spread over some 1,117 metres. This facility is on a sloping site with a concave profile to ensure visibility between all pillars. There is a brass plate fitted with a 5/8-inch UNC threaded bolt on top of each pillar. A lockable cap covers the top of each pillar.
The first 4 pillars are at chainages of 0m, 5m, 7.5m and 47.3m. The unit length of the EDM under test will govern which two pillars to occupy. Temperature and pressure must be recorded with each distance measurement.
Using the Baseline
To calibrate your EDM equipment, please follow the procedure below:
- Download the EDM calibration handbook [3.1 MB] to familiarise yourself with the recommended field procedures and software requirements.
- Download and print copies of the EDM calibration booking sheet [278.4 KB]
- Email actplasurvey@act.gov.au to make your reservation at the baseline.
Combination locks are fitted to the access gate and the pillar lids. The combination code will be provided at the time of booking.
You must supply your own thermometers, barometers, and umbrellas. Field meteorological equipment can be compared to the standardised thermometers and barometers of the Office of the Surveyor-General and Land Information (OSGLI).
Calculate the results
To assist surveyors to calibrate EDM equipment against a standard baseline, EDM calibration software called Baseline (version 6.1.0.3) is available for use. Please contact OSGLI to obtain a distribution copy of this software.
A copy of the calibration report must be lodged with the OSGLI after the computation is complete. Otherwise, it needs to be lodged with a related survey plan lodgement.
To obtain a copy of the Baseline software or lodge a calibration report, email actplasurvey@act.gov.au.
