Geodesy is the science which provides the methods and models required to determine the shape, gravity field and rotation of the Earth. It is thus the theoretical basis of surveying (the practice of positioning) and it is closely related to Geophysics, Oceanography, Astronomy, Geology, Atmospheric Science and Space Science.
Engineering Geodesy is the geodetic branch related to the determination of the shape, position, orientation, movement and deformation of objects with sizes ranging from a few centimeters to several kilometers. The methods and systems provided by engineering geodesy allow for instance
- tunnels to be built simultaneously from opposite ends
- dams to be operated safely
- railway tracks to be laid out and kept in a condition such as to allow a smooth and comfortable ride
- large airplanes to be assembled perfectly
- manufacturing robots to be calibrated for precise motion control
Engineering surveyors thus closely cooperate with civil engineers, geotechnical engineers, mechanical engineers and others. They typically have to provide results of utmost accuracy and reliability. Often the admissible errors must not exceed a few millimeters and the temporal resolution must be on the order of a few seconds. Engineering surveyors know how to use total stations, GNSS devices, levels, tilt meters and other sensors, how to provide a sufficiently stable reference frame, how to reduce the respective inherent systematic deviations, how to cope with physical limitations e.g. posed by the atmosphere, and how to control their equipment, measurements and results in order to meet such stringent requirements.