World Geodetic System (WGS): global reference for coordinates and heights
The World Geodetic System is the international standard datum and coordinate framework used for mapping, navigation and geodesy; WGS 84 is the current reference model.
The World Geodetic System (WGS) is a suite of standards that defines how positions and heights are referenced on and above the Earth. It is widely used in cartography, geodesy and satellite-based navigation, most notably the Global Positioning System (GPS). WGS provides a common mathematical framework so different maps, sensors and instruments can interoperate and share location data accurately.
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Core components
WGS combines several related concepts into a single system. The principal elements are:
- Reference coordinate system: an Earth-centered, Earth-fixed three-dimensional Cartesian system used to express latitude, longitude and ellipsoidal height; see coordinate system.
- Reference ellipsoid: a smooth mathematical surface approximating the Earth's shape, used for computing positions relative to the center of mass of the Earth.
- Vertical datum and geoid model: a model of mean sea level used to convert ellipsoidal heights to conventional heights; raw altitude values are standardized in WGS and the geoid is part of that definition (altitude, geoid).
History and development
WGS evolved in the 20th century to meet the needs of global mapping and navigation. Early versions addressed inconsistencies between national geodetic datums. The most recent major release, WGS 84, was developed for satellite navigation and has been updated periodically to account for improved measurements, tectonic motion and changes in the Earth’s mass distribution.
Uses and importance
WGS is the de facto reference for GPS receivers, international charts, and many GIS datasets. Typical applications include maritime and aviation navigation, land surveying, remote sensing, emergency response, and location-based services. Using a common datum minimizes errors when combining datasets from different sources.
Notable distinctions
WGS is a global, Earth-centered datum, unlike many local datums that were optimized for a single region. Its ellipsoid is chosen to fit the planet as a whole rather than any single country, which makes it highly suitable for global systems but sometimes less accurate locally without regional adjustments.
Because the Earth's surface and gravity field change slowly, WGS remains a living standard: agencies publish refinements and transformations to map between WGS and other datums. For detailed specifications and conversion procedures consult official geodetic authorities and technical documentation.
Questions and answers
Q: What is the World Geodetic System (WGS)?
A: The World Geodetic System (WGS) is a standard used in cartography, geodesy, and navigation including GPS.
Q: What does the WGS include?
A: The WGS includes a standard coordinate system for the Earth, a standard for raw altitude data, and a geoid that defines the nominal sea level.
Q: What is the latest revision of the WGS?
A: The latest revision of the WGS is WGS 84.
Q: What is the purpose of the WGS coordinate system?
A: The purpose of the WGS coordinate system is to provide a standard reference frame for coordinates on the Earth's surface.
Q: Why is the WGS important for navigation?
A: The WGS is important for navigation because it provides a coordinate system that can be used with GPS to determine a location on the Earth's surface.
Q: What is the geoid in the WGS?
A: The geoid in the WGS is a surface that represents the Earth's mean sea level according to gravity.
Q: What is the benefit of using the WGS in cartography?
A: The benefit of using the WGS in cartography is that it provides a uniform coordinate system that can be used by mapmakers around the world to create accurate and consistent maps.
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AlegsaOnline.com World Geodetic System (WGS): global reference for coordinates and heights Leandro Alegsa
URL: https://en.alegsaonline.com/art/109087