Reference ellipsoid
(Redirected from Geodetic coordinates)
Reference Ellipsoid[edit | edit source]
A reference ellipsoid is a mathematically defined surface that approximates the geoid, which is the true physical shape of the Earth. It is an ellipsoid of revolution, meaning it is formed by rotating an ellipse about its minor axis. Reference ellipsoids are used in geodesy, cartography, and astronomy to provide a simple model of the Earth's shape for various calculations and measurements.
Coordinates[edit | edit source]
The coordinates on a reference ellipsoid are typically given in terms of latitude, longitude, and ellipsoidal height. These coordinates are essential for accurately mapping and navigating the Earth's surface.
Latitude[edit | edit source]
Latitude is the angle between a point on the Earth's surface and the equatorial plane. It is measured in degrees, with positive values indicating locations north of the equator and negative values indicating locations south of the equator.
Longitude[edit | edit source]
Longitude is the angle between a point on the Earth's surface and the prime meridian, which passes through Greenwich, England. It is also measured in degrees, with positive values indicating locations east of the prime meridian and negative values indicating locations west of the prime meridian.
Ellipsoidal Height[edit | edit source]
Ellipsoidal height (or geodetic height) is the distance from a point on the Earth's surface to the reference ellipsoid, measured along the normal to the ellipsoid. It is different from orthometric height, which is measured from the geoid.
Applications[edit | edit source]
Reference ellipsoids are used in various fields:
- In geodesy, they provide a basis for defining geodetic datums, which are coordinate systems used to map the Earth's surface.
- In cartography, they help in creating accurate maps and charts.
- In astronomy, they assist in calculating the positions of celestial objects relative to the Earth.
Common Reference Ellipsoids[edit | edit source]
Several reference ellipsoids have been defined for different purposes:
- The WGS 84 (World Geodetic System 1984) is widely used for GPS and other global applications.
- The GRS 80 (Geodetic Reference System 1980) is used for geodetic measurements and mapping.
- The Clarke 1866 ellipsoid was historically used in North America.
See Also[edit | edit source]
Related Pages[edit | edit source]
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
WikiMD's Wellness Encyclopedia |
Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Translate this page: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
தமிழ்,
తెలుగు,
Urdu,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
বাংলা
European
español,
Deutsch,
français,
Greek,
português do Brasil,
polski,
română,
русский,
Nederlands,
norsk,
svenska,
suomi,
Italian
Middle Eastern & African
عربى,
Turkish,
Persian,
Hebrew,
Afrikaans,
isiZulu,
Kiswahili,
Other
Bulgarian,
Hungarian,
Czech,
Swedish,
മലയാളം,
मराठी,
ਪੰਜਾਬੀ,
ગુજરાતી,
Portuguese,
Ukrainian
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD