plane table
Quick Summary
A plane table is a surveying instrument used for plotting observations directly onto a map in the field. It consists of a drawing board mounted on a tripod, allowing it to be rotated and fixed. Surveyors use an alidade, a ruler with sights, to direct the instrument toward observed features. Pencil rays are drawn along the alidade, and by taking readings from multiple points, the map positions of these features can be determined where the rays intersect. This method is particularly useful in open, hilly, or mountainous terrain for recording data directly from observation.12
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