Surveying in Antarctica during the International Geophysical Year

The Antarctic International Geophysical Year (IGY) scientists discovered that the existing maps contained many errors, particularly where the original exploration was by aircraft. An expedition of two DC-3 aircraft was taken to the Ellsworth Station on the Weddell Sea. A test network of 10 control points was established 200 miles south of the Ellsworth Station on the Filchner Ice Shelf in the vicinity of the Pensacola Mountains. The Positions of these points were determined by solar altitude measurements made every hour for 24 hours. U.S. Geological Survey topographic engineers were to survey any mountain ranges by establishing positions by solar altitude measurement and elevations by barometric altimetry. Aerial photographs over major mountain ranges using P-2V aircraft equipped with trimetrogon cameras was combined with the control established by the surveyors at the U.S. Geological Survey, to produce 1:250,000-scale topographic maps. The first maps produced covered the Thurston Peninsula, Sentinel Mountains, Horlick Mountains, Executive Committee Range, and McMurdo Sound.