This article is about longitude and latitude; see also UTM coordinate system // Transverse Mercator Projection A Transverse Mercator projection A Transverse Mercator projection is an adaptation of the Mercator projection. ...

Map of Earth showing lines of latitude (horizontally) and longitude (vertically); large version (pdf)

The geographic (earth-mapping) coordinate system expresses every horizontal position on Earth by two of the three coordinates of a spherical coordinate system which is aligned with the spin axis of the Earth. It defines two angles measured from the center of the Earth: Based on a screenshot of a CIA World Factbook PDF. I cropped it, added text labels, and changed file format. ... Based on a screenshot of a CIA World Factbook PDF. I cropped it, added text labels, and changed file format. ... Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third planet outward from the Sun. ... Latitude, denoted by the Greek letter φ, gives the location of a place on Earth north or south of the Equator. ... Map of Earth showing curved lines of longitude Longitude, sometimes denoted by the Greek letter λ, describes the location of a place on Earth east or west of a north-south line called the Prime Meridian. ... This article describes some of the common coordinate systems that appear in elementary mathematics. ... Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third planet outward from the Sun. ...

• the latitude (Lat.) measures the angle between any point and the equator, measured along a meridian.
• the longitude (Long.) measures the angle east-wards along the equator from an arbitrary point on the Earth: Greenwich in London (U.K.) is the accepted zero-longitude point internationally in most modern societies.

By combining these two angles, the horizontal position of any location on Earth can be specified. For example, Baltimore, Maryland (in the USA) has a latitude of 39.3 degrees North, and a longitude of 76.6 degrees West (39.3° N 76.6° W). So, a vector drawn from the center of the Earth to a point 39.3 degrees north of the equator and 76.6 degrees west of Greenwich will pass through Baltimore. Latitude, denoted by the Greek letter φ, gives the location of a place on Earth north or south of the Equator. ... The equator is an imaginary line drawn around a planet, halfway between the poles. ... Meridian is: Meridian (astronomy): an imaginary circle perpendicular to the horizon. ... Map of Earth showing curved lines of longitude Longitude, sometimes denoted by the Greek letter λ, describes the location of a place on Earth east or west of a north-south line called the Prime Meridian. ... Greenwich (pronounced gren-itch , or by the locals) is a town, now part of the south eastern urban sprawl of London, on the south bank of the river Thames in the London Borough of Greenwich. ... St. ... The United Kingdom of Great Britain and Northern Ireland is a country in western Europe, and a member of the European Union. ... Motto: BELIEVE (formerly The City That Reads) Nickname: Charm City Location in Maryland Founded  -Incorporated 30 July 1729 1797  County Independent city Mayor Martin J. OMalley (Dem) Area  - Total  - Water 349. ...

Traditionally, degrees have been divided into minutes ( ' ) and seconds ( " ). Decimal division is now more common. They can be in any one of this three formats, appearing first in a Lat.-Long. order : A minute of arc, arcminute, or MOA is a unit of angular measurement, equal to one sixtieth (1/60) of one degree. ... A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 ≈ 7. ...

• DM Degree:Minute (49:30.0-123:30.0)
• DMS Degree:Minute:Second (49:30:00-123:30:00)
• DD Decimal Degree (49.5000-123.5000), generally with 4 decimal numbers

To change from DM or DMS to DD, Decimal degrees = whole number of degrees, plus minutes divided by 60, plus seconds divided by 3600.

The equator is obviously an important part of this coordinate system, it represents the zeropoint of the latitude angle, and the halfway point between the poles. The equator is the fundamental plane of the geographic coordinate system. All spherical coordinate systems define such a fundamental plane. The fundamental plane in a spherical coordinate system is a plane which divides the sphere into two hemispheres. ...

Lines of constant latitude are called parallels. They trace circles on the surface of the Earth, but the only parallel that is a great circle is the equator (latitude=0 degrees). Lines of constant longitude are called meridians. The meridian passing through Greenwich is the Prime Meridian (longitude=0 degrees). Unlike parallels, all meridians are great circles, and meridians are not parallel: they intersect at the north and south poles. The mesh of intersecting parallels and meridians is called a graticule. The term Parallel has a number of important meanings: Parallel (geometry) occurs in geometry. ... A great circle on a sphere A great circle is a circle on the surface of a sphere that has the same diameter as the sphere, dividing the sphere into two equal hemispheres. ... Meridian is: Meridian (astronomy): an imaginary circle perpendicular to the horizon. ... The Prime Meridian, Greenwich The Prime Meridian is the meridian (line of longitude) passing through the Royal Greenwich Observatory, Greenwich, England; it is the meridian at which longitude is 0 degrees. ...

This article originates from Jason Harris' Astroinfo which comes along with KStars, a Desktop Planetarium for Linux/KDE. See http://edu.kde.org/kstars/index.phtml Screenshot of KStars showing the night sky from Hanover. ... Tux, a cartoon penguin frequently featured sitting, is the official Linux mascot. ... KDE (Kool Desktop Environment) is a free desktop environment and development platform built with Trolltechs Qt toolkit. ...

To be merged:

Latitude and longitude are arbitrary measurements used to describe any point on the Earth, or similar globe. Borrowing from theories of ancient Babylonians, later expanded by the famous Greek thinker and geographer Ptolemy, a full circle is assigned 360 degrees. Latitude is the term for the distance from the middle of the circle, or, in the case of the Earth, the equator. The equator is designated 0 degrees, with each pole being 90 degrees. Longitude is the horizontal measurement--current convention places the zero degree point at Greenwich, England (also known as the Prime Meridian), with 180 degrees being on the opposite point on the globe. Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third planet outward from the Sun. ... Babylonia was an ancient state in Iraq), combining the territories of Sumer and Akkad. ... Claudius Ptolemaeus, given contemporary German styling, in a 16th century engraved book frontispiece Claudius Ptolemaeus (Greek: Κλαύδιος Πτολεμαῖος; c. ... Latitude, denoted by the Greek letter φ, gives the location of a place on Earth north or south of the Equator. ... The equator is an imaginary line drawn around a planet, halfway between the poles. ... Map of Earth showing curved lines of longitude Longitude, sometimes denoted by the Greek letter λ, describes the location of a place on Earth east or west of a north-south line called the Prime Meridian. ... Greenwich (pronounced gren-itch , or by the locals) is a town, now part of the south eastern urban sprawl of London, on the south bank of the river Thames in the London Borough of Greenwich. ... Royal motto: Dieu et mon droit (French: God and my right) Englands location within the UK Official language English de facto Capital London de facto Largest city London Area  - Total Ranked 1st UK 130,395 km² Population  - Total (2001)  - Density Ranked 1st UK 49,138,831 377/km² Ethnicity... The Prime Meridian, Greenwich The Prime Meridian is the meridian (line of longitude) passing through the Royal Greenwich Observatory, Greenwich, England; it is the meridian at which longitude is 0 degrees. ...

Lines of longitude are all of the same length whereas those of latitude vary in length.

Third dimension : altitude

To completely specify a location on, in, or above the Earth, one has to specify also the elevation / height position. This can e.g. be expressed relative to a datum such as mean sea level (above mean sea level) or the geoid. The distance to the Earth's center is a practical coordinate both for very deep positions and for positions in space. It has been suggested that this article or section be merged with Geodetic system. ... For considerations of sea level change, in particular rise associated with possible global warming, see sea level rise. ... The term above mean sea level (AMSL) refers to the elevation (on the ground) or altitude (in the air) of any object, relative to the average sea level. ... The GOCE project will measure high-accuracy gravity gradients and provide an accurate geoid model based on the Earths gravity field. ...

The elevation specifies the vertical position of the Earth surface.

Various elevation / height coordinates either with respect to the surface or some other datum are altitude, height, and depth. Altitude is the elevation of an object from a known level or datum, called zero level. ... Height is a measurement of the distance from the bottom to the top of something which is upright. ... Look up depth in Wiktionary, the free dictionary In classical physics, depth is a distance measured vertically from top to bottom (height) or horizontally from outside to inside (thickness). ...

Geostationary coordinates =

Geostationary satellites (i.e. television satellites ) are over the Equator. So, their possition related to the earth is expressed longitude degrees (latitude is zero in the Equator). A geostationary orbit (abbreviated GEO) is a circular orbit in the Earths equatorial plane, any point on which revolves about the Earth in the same direction and with the same period as the Earths rotation. ...

See also

• GIS
• GPS
• Geographic coordinates (obtaining)
• Geographic coordinate conversion
• geocodes
• Tropic of Cancer
• Tropic of Capricorn
• Great circle distance explains how to find that quantity if one knows the two latitudes and longitudes.
• Map projection

A geographic information system (GIS) is a system for managing data that has a spatial specialized form of an information system. ... Over fifty GPS satellites such as this NAVSTAR have been launched since 1978. ... Methods to obtain geographic coordinates of a place include: Category:Lists of coordinates Manually: Looking at a printed map or atlas, either those you own or at a library Using a GPS satellite navigator On the web: Multimap provides geographic coordinates of a location selected from a map. ... Geographic coordinates consist of latitude and longitude. ... A geocode is a geographical code to identify a point or area at the surface of the earth. ... The Tropic of Cancer (cancer (♋) is Latin for crab) is one of the five major circles of latitude that mark maps of the Earth. ... The Tropic of Capricorn is one of the five major circles of latitude that mark maps of the Earth. ... Great circle distance is the shortest distance between any two points on the surface of the Earth measured along a path on the surface of the Earth (as opposed to going through the Earths interior). ... The Mercator projection shows courses of constant bearing as straight lines. ...

External links

• Mathematics Topics-Coordinate System
• How to find your latitude and longitude
• Geographic coordinates of countries (CIA World Factbook)
• Coordinates systems.
• Degrees, Minutes, Seconds to Decimal Degrees calculator.