Development of photogrammetry in the U.S. Geological Survey

Photogrammetry, the science or art of obtaining reliable measurements by means of photography, is now used extensively in topographic mapping. Precise photogrammetric plotting instruments now enable the map maker to extract from aerial photographs much.of the detailed information required for drawing the map that formerly was acquired by laborious ground surveys. Photography and photogrammetry have thus become essential components of all large mapping operations.

The Geological Survey has played a leading role in the development of photogrammetric methods of mapping over a period of half a century. This role has been well documented in numerous articles appearing in technical publications during this time. It is the purpose of this circular to present, in brief form, the highlights of Geological Survey activities and developments in the field of photogrammetry, from pioneer efforts to present-day practice.