What is geodesy?

Geodesy is the scientific discipline dedicated to measuring and representing Earth's geometric shape, spatial orientation, and gravity field in temporally varying three-dimensional space. It provides the essential framework for mapping, navigation, satellite systems, and precise timekeeping. Through techniques like space geodesy and global control networks, it also tracks dynamic phenomena such as crustal motion and polar motion.

What we know

• Geodesy is the science of measuring and representing the geometry, gravity, and spatial orientation of Earth in temporally varying 3D space. [1, 2]
• It provides the scientific basis for mapping, navigation, positioning, infrastructure development, natural resource management, and geophysics. [2]
• Geodetic measurements underpin modern geospatial reference frames used in transportation, satellite systems, global trade, and timekeeping. [2]
• Geodynamic phenomena including crustal motion, tides, and polar motion are studied using space geodesy and terrestrial geodetic techniques. [2]

Where to go next

• how it workedHow does space geodesy work?
• what followedHow do geospatial reference frames support global timekeeping?
• compared withWhat is planetary geodesy?
• the bigger pictureWhat is the International Association of Geodesy?
• a case in pointWhat does the Geodetic Observatory Wettzell do?
• an unexpected connectionWhy was a German mapping and geodesy agency targeted in a cyber-attack?National mapping and geodetic agencies handle sensitive spatial infrastructure data that can become targets for state-sponsored espionage.

Sources

• [1]geodesy (Wikidata Q131089) · CC0 1.0
• [2]Geodesy · CC BY-SA 4.0
• [3]International Association of Geodesy · CC BY-SA 4.0
• [4]Federal Agency for Cartography and Geodesy · CC BY-SA 4.0
• [5]Equator · CC BY-SA 4.0