Geodesy

Geodesy (pronunciation: /dʒiːˈɒdᵻsi/), — also known as geodetics, geodetic engineering or geodetics engineering — a branch of applied mathematics and earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth (or any planet), including its gravitational field, in a three-dimensional time-varying space. Geodesists also study geodynamical phenomena such as crustal motion, tides, and polar motion. For this they design global and national control networks, using space and terrestrial techniques while relying on datums and coordinate systems.

Geodesy — from the Ancient Greek word γεωδαισία geodaisia (literally, "division of the Earth") — is primarily concerned with positioning within the temporally varying gravity field. Geodesy in the German-speaking world is divided into "higher geodesy" ("Erdmessung" or "höhere Geodäsie"), which is concerned with measuring the Earth on the global scale, and "practical geodesy" or "engineering geodesy" ("Ingenieurgeodäsie"), which is concerned with measuring specific parts or regions of the Earth, and which includes surveying. Such "geodetic" operations are also applied to other astronomical bodies in the solar system. It is also the science of measuring and understanding the earth's geometric shape, orientation in space and gravity field.

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