Reference Work Entry

Encyclopedia of Solid Earth Geophysics

Part of the series Encyclopedia of Earth Sciences Series pp 316-323

Date:

Geodesy, Ground Positioning and Leveling

  • Stelios P. MertikasAffiliated withLaboratory of Geodesy and Geomatics Engineering, Exploration and Positioning Division, Department of Mineral Resources Engineering, Technical University of Crete Email author 

Synonyms

Height determination; Terrestrial positioning

Definition

Geodesy. Science for the determination and representation of the figure, shape, size of the Earth and of other celestial bodies along with their external gravity field as a function of time.

Positioning. Determination of coordinates for points on earth, sea, or space with respect to a reference system.

Ground positioning. Determination of terrestrial coordinates.

Leveling. The determination of heights of points with respect to a reference surface.

Introduction

Geodesy, along with Astronomy, is considered the oldest earth science, and dates back to the Sumerians of 5,000 years ago. The word “geodesy” is composite and is derived from the Greek noun «Γη = earth» and the verb «δαίω = divide». It is, literally, the science used to “divide, distribute, and measure the Earth.” The roots of geodesy can be found in ancient Egypt and Babylon where “the geometry of the Earth” was used for the recovery of the l ...

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