Geodesy

Geodesy (, jee-OD-iss-ee) or geodetics is the science of measuring and representing the geometry, gravity, and spatial orientation of the Earth in temporally varying 3D space. It is called planetary geodesy when studying other astronomical bodies, such as planets or circumplanetary systems. Geodetic job titles include geodesist and geodetic surveyor. Through highly accurate observations, geodesy provides the scientific basis for mapping, navigation, and positioning, and supports applications such as infrastructure development (including construction), natural resource management, mineral exploration, and geophysics. Its measurements underpin modern geospatial reference frames used in transportation, satellite systems, global trade, and timekeeping. Geodynamic phenomena, including crustal motion, tides, and polar motion, are studied through global and national control networks, space geodesy and terrestrial geodetic techniques, and the use of datums and coordinate systems.