Geomatics is the science and technology of gathering, analyzing, interpreting, distributing, and using geographic (or spatially referenced) information. It encompasses a broad range of disciplines, including:

1. Surveying: The measurement and mapping of the Earth’s surface, both on land and underwater.
2. Mapping: Creating accurate representations of geographical features, such as topographic maps.
3. Remote Sensing: Collecting data from satellites, aircraft, or other sensors to study the Earth’s surface.
4. Geographic Information Systems (GIS): Software systems for managing, analyzing, and visualizing spatial data.
5. Global Positioning Systems (GPS): Satellite-based navigation systems that provide precise location information.

Source: Geomatics - GIS Wiki | The GIS Encyclopedia

ToC

GIS

UTM

3D GIS

Geospatial Indexing

(lat, lon) or [lon, lat]?

WGS & CRS’s

EPSG.io: Coordinate Systems Worldwide

Spatial Reference

WGS84: World Geodetic System 1984

The World Geodetic System (WGS) is a standard used in cartography, geodesy, and satellite navigation including GPS. The current version, WGS 84, defines an Earth-centered, Earth-fixed coordinate system and a geodetic datum, and also describes the associated Earth Gravitational Model (EGM) and World Magnetic Model (WMM). The standard is published and maintained by the United States National Geospatial-Intelligence Agency. Source: World Geodetic System | Wikipedia

WGS84 comprises of 4 things:

1. Ellipsoid: an ellipsoid that approximates the shape of the earth
2. Horizontal datum: ellipsoid + anchor point
3. Vertical datum: WGS84 ellipsoid
4. Coordinate system: horizontal datum + prime meridian + angular unit

Source: What is WGS84? | Virtual Surveyor

Geoid vs Ellipsoid

• Both geoids and ellipsoids are vertical datums.
• An ellipsoid, such as the WGS84 ellipsoid, is an ellipsoid approximation of the earth’s surface.
• The surface of a geoid represents the Mean Sea Level (MSL). The only factor that affects the MSL, i.e. geoid’s shape, is the earth’s gravity, when effects due to tides and winds are removed.

Height types

• Ellipsoid height (h) = height w.r.t. ellipsoid
• Orthometric height (H) = height w.r.t. geoid, i.e. height w.r.t. Mean Sea Level