Geodetic Surveyors

Geodetic surveyors, also known as geodesists, take highly accurate and detailed measurements of the earth's surface that show land contours and elevations. They conduct surveys of areas for proposed construction projects such as highways, airstrips, and housing developments. They usually work with a field party that includes instrument assistants, known as surveying and mapping technicians, who handle surveying instruments including the theodolite, transit, level, surveyor's chain, rod, and other electronic equipment. Throughout the survey work all readings must be recorded accurately and field notes maintained so that the survey can be checked for accuracy.

Geodetic surveyors measure large masses of land, sea, and space that must take into account the curvature of Earth and its geophysical characteristics. Their work is helpful in establishing points of reference for smaller land surveys, determining national boundaries, and preparing maps. Geodetic computers calculate latitude, longitude, angles, areas, and other information needed for mapmaking. They work from field notes made by an engineering survey party and also use reference tables and a calculating machine or computer.

Geodetic surveyors may work on construction projects, such as highways, bridges, airstrips, shopping centers, and housing developments, establishing grades, lines, and other points of reference. This information is essential to the work of the many engineers and construction crews who build these projects. There are also land surveyors who specialize in geodetic work. These surveyors establish township, property, and other tract-of-land boundary lines. In addition to using satellite data, they also use maps, notes, or actual land title deeds to survey the land, checking for the accuracy of existing records. This information is used to prepare legal documents such as deeds and leases.

Other areas of work for geodetic surveyors may include mine surveying, to conduct surface and underground surveys and prepare maps of mines and mining operations; geophysical prospecting, to locate and mark sites that may contain petroleum deposits; and oil-well directional surveying, which uses sonic, electronic, and nuclear measuring instruments to gauge the presence and amount of oil- and gas-bearing reservoirs. There are also pipeline surveys to determine rights-of-way for oil construction projects, which provides information essential to the preparation for and laying of the lines.

Geodetic surveyors may also work closely with photogrammetric engineers, also known as photogrammetrists. They may help them to determine the contour of an area to show elevations and depressions and indicate such features as mountains, lakes, rivers, forests, roads, farms, buildings, and other landmarks. Aerial, land, and water photographs are taken with special equipment able to capture images of large areas, and accurate measurements of the terrain and surface features are made from the photographs. These surveys are helpful in construction projects and in preparing topographical maps, and are especially helpful in charting areas that are inaccessible or difficult to travel.

Geodetic surveyors may also specialize in cartography, preparing maps, charts, and drawings from aerial photographs and survey data. They also conduct map research, developing new mapping techniques and investigating topics such as how people use maps. Geodetic surveyors must have strong knowledge of a variety of software programs.