File:DavidsonTrig.jpg
From ACT Govt info on Survey Control Marks - In the ACT trig stations consist of a ground mark with a white quadripod supporting a black disc above the ground mark. Most of these Trig Stations are part of the ACT Precision Zone: a national geodetic survey and adjustment carried out in the early 1970s. The ACT Precision Zone and its associated marks have been the primary control for all new development in the ACT since the early 1970s. The accuracy of ACT Precision Zone marks is 1 in 250,000.
Further information on Geodetic survey in Australia - now and history.
(Reusing this file)