16th February 2006, 02:02 PM
Quote:quote:Originally posted by the invisible man
Way back before most of you were born, in the early 70's, there were no Total Stations, EDM's, no GIS or even Autocad. Commercial survey was basically all done by offsets. You will all have done basic survey though. The principle was exactly the same but without batteries. Stations are surveyed in by theodolite around a field and offsets taken from baselines between them in the form of a chain (yes a real one) or a 100m tape, to the boundaries (usually in a large and very prickly hedge).
The baselines were long but the offsets were short. I recall that the essential equipment list included a football.
We owe the dead nothing but the truth.
I still regularly triangulate from a baseline to avoid the inaccuracies of plain right angle off-setting. A survey point is measured from either end of the baseline. Using a pair of compasses you then intersect two arcs. Very useful if the EDM hasn't had its battery charged.