Route Survey

a survey of the earth’s surface along a particular route in the compilation and updating of topographical, geological, soil, and other maps and the correlation of selected contours and objects with geodetic reference points or landmarks during linear surveys, and also in the study of the dynamics of natural and socioeconomic phenomena in a narrow strip of terrain. In a route survey, representations of the actual course of the survey and of the plane horizontal features (including the terrain, if necessary) on both sides of it within the limits of direct visibility are plotted on a mapboard using methods of instrument surveying (plane-table, tachymetric, and aerial phototopographic surveying) or exploratory surveying.

Ground-level route surveying has been extensively used for centuries in mapping inaccessible areas. In the 20th century aerial route surveying (instrumental and, less frequently, exploratory surveying from the air, particularly during aerovisual observations) has come to be used in addition to ground-level route surveying. Route surveys made from aircraft are done principally as sets of survey jobs to supplement a comprehensive areal survey; this is done on a larger scale and under different surveying conditions (for the purpose of singling out particular objects). Aerial route surveying is also done for such specific purposes as recording the ice conditions at sea, the boundaries of river flooding, and the centers of forest fires.