Geodetic coordinates
geographic coordinate system
Geodetic coordinates are a type of curvilinear orthogonal coordinate system used in geodesy based on a reference ellipsoid.
They include geodetic latitude (north/south) ϕ, longitude (east/west) λ, and ellipsoidal height h (also known as geodetic height).
The triad is also known as Earth ellipsoidal coordinates (not to be confused with ellipsoidal-harmonic coordinates).
Definitions
Longitude measures the rotational angle between the zero meridian and the measured point. By convention for the Earth, Moon and Sun, it is expressed in degrees ranging from −180° to +180°. For other bodies a range of 0° to 360° is used.
For this purpose, it is necessary to identify a zero meridian, which for Earth is usually the Prime Meridian. For other bodies a fixed surface feature is usually referenced, which for Mars is the meridian passing through the crater Airy-0. It is possible for many different coordinate systems to be defined upon the same reference ellipsoid.
Geodetic latitude measures how close to the poles or equator a point is along a meridian, and is represented as an angle from −90° to +90°, where 0° is the equator.
This brief starts where responsible research should: with the source description of “Geodetic coordinates” as geographic coordinate system. Everything that follows is an evidence route, not borrowed authority.
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The subject matters to the places & architecture register because the source frames it as geographic coordinate system. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Maps, plans, fabric surveys and administrative records can establish how the site’s name, extent and function changed over time. The source revision retrieved here is dated Jul 28, 2026. The linked authority identifier is Q109252968. None of the 0 selected statements returned an explicit reference.
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This entry incorporates text from “Geodetic coordinates” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.