Daylight Star Observations in Antarctica

Field surveys to obtain control for topographic mapping in Antarctica are executed during the continuous daylight of the austral summer. In general, control data have been obtained by determining astronomic positions and intersecting photo-identifiable features from taped bases. Recently, theodolites and electronic distance-measuring equipment have been used to traverse from the controlling astronomic positions to the desired photoidentifiable features. Before the 1961-62 field season, almost all the astronomic positions were determined by altitude measurements on the sun. A new method of position determination has been tried successfully, in which latitude, longitude, and azimuth are deduced simultaneously from azimuth observations on three or more stars. The azimuth method is described, and the observing procedures for it are outlined. Results of the astronomic work completed during 1961-62 Antarctic field season are given.