EGV – Essential Geodetic Variables

Essential variables are parameters that, when changed, directly affect the fundamental behavior or outcome of a system. Geodesy determines the Earth’s shape, rotation, and gravity field as functions of space and time. Accordingly, Essential Geodetic Variables (EGVs) comprise the minimum set of parameters required to observe, model, and understand these fundamental properties of the Earth. Building on established concepts such as Essential Climate Variables and Essential Ocean Variables, the EGVs developed by GGOS highlight the unique contribution of geodesy to monitoring the Earth’s geometry, gravity field, and orientation in space.

The EGV catalogue spans the full geodetic value chain, from observing infrastructure, standards, and conventions, through observations and intermediate products, to higher-level variables relevant to multidisciplinary Earth system research and Earth Observation.

Further details on the EGV concept and its implementation are provided in the GGOS White Paper, Definition of Essential Geodetic Variables (EGV): Contribution of Geodesy to Earth Observation.