Geodesy is the scientific study of three essential characteristics of the Earth’s geometry, orientation in space, and gravity field, as well as how these characteristics change through time. Geodesists can track a site’s movement around the clock, every day of the week, using GPS.
It is possible to determine and describe the shape of the Earth and its gravity field using applied mathematics and satellite observations, as well as to follow changes in geodynamic processes over time, including polar motion, Earth tides, and tectonic motion. Along with the variation of the gravity field and the precise geometrical characteristics of their temporal variations, geodesy is also concerned with accurately determining geographic places on Earth.
There are different coordinate systems and data related to the measurement of terrestrial distances used as baselines in surveying and mapping, as well as the calculation of the Earth’s ellipsoid and the geoid’s form. Key terms that characterize the kinematics and dynamics of the Earth as a deformable body are also defined by geodetic observations. The range of observable Earth parameters has been widened and the precision of geodynamic measurements as functions of time has risen in recent years due to the availability of satellite-produced geodetic data.
To map the U.S. shoreline, identify land boundaries, and increase the safety of navigation and transportation, many organizations use geodesy. Geodesists assign coordinates—which are akin to individual addresses—to sites all over the globe in order to measure them on the Earth’s surface. In the past, geodesists used Earth-based surveying equipment to measure the distances between places in order to calculate the coordinates of those points. Today, geodesists measure points on the surface of the Earth using space-based instruments like the Global Positioning System (GPS).