Geodesy

Clairaut's theorem is a general mathematical law applying to spheroids of revolution.

A geodetic datum or geodetic system is a coordinate system, and a set of reference points, used to locate places on the Earth (or similar objects).

A gravity anomaly is the difference between the observed acceleration of a planet's reaction to gravity and a value predicted from a model.

An indoor positioning system (IPS) is a system to locate objects or people inside a building using radio waves, magnetic fields, acoustic signals, or other sensory information collected by mobile devices.

Real Time Kinematic (RTK) satellite navigation is a technique used to enhance the precision of position data derived from satellite-based positioning systems (global navigation satellite systems, GNSS) such as GPS, GLONASS, Galileo, and BeiDou.

A circle of latitude on the Earth is an imaginary east–west circle connecting all locations (ignoring elevation) with a given latitude.

In physics, a frame of reference (or reference frame) consists of an abstract coordinate system and the set of physical reference points that uniquely fix (locate and orient) the coordinate system and standardize measurements.

In physics, a gravitational field is a model used to explain the influence that a massive body extends into the space around itself, producing a force on another massive body.

A map is a symbolic depiction highlighting relationships between elements of some space, such as objects, regions, and themes.

Photogrammetry is the science of making measurements from photographs, especially for recovering the exact positions of surface points.

Sea level is generally used to refer to mean sea level (MSL), an average level for the surface of one or more of Earth's oceans from which heights such as elevations may be measured.

Topography is the study of the shape and features of the surface of the Earth and other observable astronomical objects including planets, moons, and asteroids.

An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea.

The geoid is the shape that the surface of the oceans would take under the influence of Earth's gravity and rotation alone, in the absence of other influences such as winds and tides.

In modern mapping, a topographic map is a type of map characterized by large-scale detail and quantitative representation of relief, usually using contour lines, but historically using a variety of methods.

Commonly, a map projection is a systematic transformation of the latitudes and longitudes of locations on the surface of a sphere or an ellipsoid into locations on a plane.

A prime meridian is a meridian (a line of longitude) in a geographical coordinate system at which longitude is defined to be 0°.

A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning.

A triangulation station, also known as a triangulation pillar, trigonometrical station, trigonometrical point, trig station, trig beacon or trig point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity.

The Helmert–Wolf blocking (HWB) is a least squares solution method for a sparse canonical block-angular (CBA) system of linear equations.

3D data acquisition and reconstruction is the generation of three-dimensional or spatiotemporal models from sensor data.

Geodetic astronomy or astro-geodesy is the application of astronomical methods into networks and technical projects of geodesy.

Clairaut's relation, named after Alexis Claude de Clairaut, is a formula in classical differential geometry.