Geodesy

Geodesy is the Earth science that measures and monitors the Earth’s geometry, gravity field, rotation, and their temporal variations. It provides the scientific and technical foundation for determining precise positions on Earth and in space, establishing reference frames, and observing dynamic processes within the Earth system.

In modern geodesy, space-geodetic techniques such as GNSS, VLBI, Satellite Laser Ranging (SLR), and DORIS are combined with terrestrial measurements to realize global reference frames, monitor sea level change, crustal deformation, mass redistribution, and Earth rotation. Geodesy underpins positioning, navigation, timing, mapping, climate research, disaster risk reduction, and sustainable development worldwide.