Keywords: DavidsonTrig.jpg Davidson en Trig point on en Red Hill Australian Capital Territory From http //www actpla act gov au/actlic/surveycontrolmarks/ 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 http //www environment sa gov au/mapland/sicom/sicom/tp_scs html Geodetic survey in Australia - now and history Transferred from http //en wikipedia org en wikipedia; transferred to Commons by User Bidgee using http //tools wikimedia de/~magnus/commonshelper php CommonsHelper 2005-05-02 Original uploader was Matilda at http //en wikipedia org en wikipedia PD-USER-W EN WIKIPEDIA en wikipedia AYArktos original upload log page en wikipedia DavidsonTrig jpg 2005-05-02 00 25 Matilda 718×898× 60281 bytes <nowiki>Davidson Trig point on Red Hill Australian Capital Territory From http //www actpla act gov au/actlic/surveycontrolmarks/ ACT Govt info on Survey Control Marks - In the ACT trig stations consist of a ground mark with a white quadripod support</nowiki> Red Hill Australian Capital Territory Symmetry impressions Trig points in Australia |