Dictionary:

latitude

  (lăt'ĭ-tūd', -tyūd')

(Click to enlarge)

latitude

(Jerry Malone)

1. 1. The angular distance north or south of the earth's equator, measured in degrees along a meridian, as on a map or globe.
   2. A region of the earth considered in relation to its distance from the equator: temperate latitudes.
2. Astronomy. The angular distance of a celestial body north or south of the ecliptic.
3. Freedom from normal restraints, limitations, or regulations. See synonyms at room.
4. A range of values or conditions, especially the range of exposures over which a photographic film yields usable images.
5. Extent; breadth.

[Middle English, geographical latitude, from Old French, width, from Latin lātitūdō, width, geographical latitude, from lātus, wide.]

The location north or south of the equator, measured in degrees from the equator, which is 0. The North Pole is plus 90 degrees, and the South Pole is minus 90 degrees. Degrees are further divided into minutes and seconds.

East/West Longitude

Longitude is the location east and west of the Greenwich prime meridian in London, measured in degrees from this reference point, which is 0. Europe is plus degrees to the east, and the Americas are minus degrees to the west.

To pinpoint a location on earth, the north/south latitude (y-axis) is combined with the east/west longitude (x-axis). For example, the Empire State Building in New York is expressed in degrees, minutes and seconds as follows:

Ability to exercise judgment within a range of authority without outside interference. For example, a supervisor has the latitude to recommend employees for promotions based upon his judgment.

noun

Suitable opportunity to accept or allow something: elbowroom, leeway, margin, play, room, scope. See place, restraint/unrestraint.

Definition: freedom, room to move; scope
Antonyms: constraint, limitation, restriction

n

Definition: parallel
Antonyms: longitude, meridian

The range between the minimum and maximum film exposures to radiation that yields images of structures of which photographic density differences are discernible under normal viewing conditions. Latitude chiefly varies directly with kilovoltage and inversely with contrast. See also contrast.

geography, astronomy Applying to a point on a spherical or similar surface (the heavens being effectively a celestial sphere surrounding Earth), the distance of the point from a datum bisecting section, usually in terms of the angle subtended at the centre of the sphere by the direct line along the spherical surface from the point to the datum plane. For a rotating sphere that plane is routinely the bisecting surface transverse to the axis of rotation (notably the equatorial plane for Earth, the ecliptic for the heavens). Points of equal latitude within one hemisphere form a ring that is the intersection with the spherical surface of a plane parallel to the datum plane, so such a ring is routinely called a parallel, accorded the definite article if qualified by a specific latitudinal angle, e.g. the 60th parallel for the ring of points subtending 60°. For everyday use, latitude is expressed in (normal geometric) degrees north else south of the datum plane (i.e. the equatorial plane for Earth), hence ranges 0° to 90° arithmetically, 90°S to 90°N geographically.

Latitude is normally paired with longitude to provide unique coordinates for a point. While expressed also in terms of a central angle, longitude differs in its method by relating to the angle subtended at the centre of the relevant parallel plane by the surface line along the parallel from the point to a datum plane transverse to the parallel plane and passing through its centre. Further, there is rarely an inherent datum position for longitude in any circumstances. The worldwide standard datum reference for locations on Earth has, since 1884, been the Greenwich meridian, i.e. the planar semicircle passing through the North and South Poles (hence including the axis) and a specific point within the national observatory at Greenwich, England (see Greenwich Mean Time for particulars and additional discussion); previously each country of significance had its own datum line. Longitude is normally expressed in degrees east else west of that meridian, and hence ranges 0° to 180°W, 0° to 180°E geographically. Points of equal longitude within one hemisphere form a semicircle that is the intersection with the spherical surface of a plane containing the axis, called a meridian for a hemisphere stretching Pole to Pole (and accorded the definite article if qualified by a specific longitudinal angle). The distance between two points of different longitude but identical latitude depends on the value of the common latitude as well as their distinct longitudes, while the distance between two points of different latitude but identical longitude depends only on their latitudes.

Because Earth is not a true sphere, the angle of latitude differs as to whether it relates to the line through the centre of Earth or the line orthogonal to the local tangent plane (i.e. the line of a plumb-line). Called respectively geocentric and geodesic latitude, the latter is the only practical one. (The two are identical at the Equator and at the Poles, otherwise the geodesic is greater. The difference increases progressively with increasing latitude until 45°, at which it is about a fifth of a degree; then it decreases progressively. An interesting consequence is that the natural nautical mile increases progressively from Equator to Poles, despite the radius decreasing.)

Terrestrial latitude and terrestrial longitude refer to the familiar latitude and longitude for Earth's surface, measured as indicated relative to the Earth's equatorial plane and the Greenwich meridian. Duly qualified and defined, latitude and longitude are applied similarly to the Sun, its other planets, and other objects in the solar system.

The celestial latitude of a star or such is measured relative to the ecliptic, with Earth as the centre; celestial longitude, which ranges 0 to 360°, has the First Point of Aries as its zero value, a moving reference reset each year. Compare right ascension for a form of longitude for celestial objects that uses Earth's equatorial plane as a datum, the related latitude being called declination.

The galactic latitude of a star within our galaxy (the Milky Way) is measured relative to the plane of symmetry of the galaxy (the galactic equatorial plane, conventionally accepted as being at angle 62° to the celestially extended equatorial plane), with the nearest point in the galactic plane to Earth as its centre. The centre of the Galaxy (in constellation Saggitarius, at sidereal hour angle 94.4° along the galactic Equator) is given as 0° galactic longitude, which is routinely positive.
[McGraw-Hill Dictionary of Scientific and Technical Terms, 5th edn (New York, McGraw-Hill, 1994)]

Parallels of latitude are imaginary circles drawn round the earth parallel to the equator. The parallels are numbered according to the angle formed between a line from the line of latitude to the centre of the earth and a line from the centre of the earth to the equator.

Those regions lying within the Arctic and Antarctic circles, having values of 66.5° to 90° are termed high latitudes. Low latitudes lie between 23.5° north and south of the equator, i.e. within the tropics. Mid-latitudes, also known as temperate latitudes, lie between the two.

1. The perpendicular distance in a horizontal plane of a point from an east-west axis of reference.
2. In surveying, the north-south component of a traverse course.

The measurement, in degrees, of a place's distance north or south of the equator. (Compare longitude.)

This article is about the geographical term. For other uses, see Latitude (disambiguation).

Map of Earth
Longitude (λ)
Lines of longitude appear curved and vertical in this projection, but are actually halves of great circles.
Latitude (φ)
Lines of latitude appear straight and horizontal in this projection, but are actually circular with different radii. All locations with a given latitude are collectively referred to as a circle of latitude.
The equator divides the planet into a Northern Hemisphere and a Southern Hemisphere, and has a latitude of 0°.

Latitude, usually denoted symbolically by the Greek letter phi, , gives the location of a place on Earth north or south of the equator. Lines of Latitude are the horizontal lines shown running east-to-west on maps. Technically, Latitude is an angular measurement in degrees (marked with °) ranging from 0° at the Equator (low latitude) to 90° at the poles (90° N for the North Pole or 90° S for the South Pole; high latitude). The complementary angle of a latitude is called the colatitude.

Circles of latitude

Main article: Circle of latitude

All locations of a given latitude are collectively referred to as a circle of latitude or line of latitude or parallel, because they are coplanar, and all such planes are parallel to the equator. Lines of latitude other than the Equator are approximately small circles on the surface of the Earth; they are not geodesics since the shortest route between two points at the same latitude involves moving farther away from, then towards, the equator (see great circle).

Sign in northern Vermont.

A specific latitude may then be combined with a specific longitude to give a precise position on the Earth's surface (see satellite navigation system).

Important named circles of latitude

Besides the equator, four other lines of latitude are named because of the role they play in the geometrical relationship with the Earth and the Sun:

• Arctic Circle — 66° 33′ 39″ N
• Tropic of Cancer — 23° 26′ 21″ N
• Tropic of Capricorn — 23° 26′ 21″ S
• Antarctic Circle — 66° 33′ 39″ S

Only at latitudes between the Tropics is it possible for the sun to be at the zenith. Only north of the Arctic Circle or south of the Antarctic Circle is the midnight sun possible.

The reason that these lines have the values that they do lies in the axial tilt of the Earth with respect to the sun, which is 23° 26′ 21.41″.

Note that the Arctic Circle and Tropic of Cancer and the Antarctic Circle and Tropic of Capricorn are colatitudes since the sum of their angles is 90°.

Subdivisions

As Earth is not a smooth sphere, but slightly oblate, a degree of latitude varies in length from about 111.3195 km at the equator to 110.9462 km at the poles. A degree of arc at a latitude not only varies with latitude, but also with the direction being faced. To simplify calculations where elliptical consideration is not important, the nautical mile was created, equaling exactly 111.12 km per degree of arc or, sub-dividing into minutes, 1852 metres per minute of arc. One minute of latitude can be further divided into 60 seconds. A latitude is thus specified as 13°19'43″ N (for greater precision, a decimal fraction can be added to the seconds). An alternative representation uses only degrees and minutes, where the seconds are expressed as a decimal fraction of minutes, thus the above example is expressed as 13°19.717' N. Degrees can also be expressed singularly, with both the minutes and seconds incorporated as a decimal number and rounded as desired (decimal degree notation): 13.32861° N. Sometimes, the north/south suffix is replaced by a negative sign for south (−90° for the South Pole).

Effect of latitude

A region's latitude has a great effect on its climate and weather (see Effect of sun angle on climate). Latitude more loosely determines tendencies in polar auroras, prevailing winds, and other physical characteristics of geographic locations.

Researchers at Harvard's Center for International Development (CID) found in 2001 that only three tropical economies — Hong Kong, Singapore, and part of Taiwan — were classified as high-income by the World Bank, while all countries within regions zoned as temperate had either middle- or high-income economies.^[1]

Types of latitude

Because the Earth is slightly flattened by its rotation, cartographers refer to a variety of auxiliary latitudes to precisely adapt spherical projections according to their purpose.
More generally, for other planets such as Mars, geographic and geocentric latitude are called "planetographic" and "planetocentric" latitude, respectively. Most maps of Mars since 2002 use planetocentric coordinates.

Common "latitude"

• In common usage, "latitude" refers to geodetic or geographic latitude and is the angle between the equatorial plane and a line that is normal to the reference spheroid, which approximates the shape of the Earth to account for flattening of the poles and bulging of the equator.

The expressions following assume elliptical polar sections with the angular eccentricity, (which equals , where and are the equatorial and polar radii), and that all sections parallel to the equatorial plane are circular. Geographic latitude (with longitude) then provides a Gauss map. Utilized in some of these conversions is a common elliptic integrand:

Reduced latitude

• Reduced or parametric latitude, , is the latitude of the same radius on the sphere with the same equator.

Authalic latitude

• Authalic latitude, , gives an area-preserving transform to the sphere.

Failed to parse (unknown function\begin): \begin{align}\xi&=\arcsin\!\left(\frac{\widehat{S}(\phi)^2}{\widehat{S}(90^\circ)^2}\right),\\ &=\arcsin\!\left(\frac{\sin(\phi)\sin(o\!\varepsilon)n'(\phi)^2+\ln\Big(n'(\phi)\big(1+\sin(\phi)\sin(o\!\varepsilon)\big)\Big)}{\sin(o\!\varepsilon)\sec(o\!\varepsilon)^2+\ln\Big(\sec(o\!\varepsilon)\big(1+\sin(o\!\varepsilon)\big)\Big)}\right);\end{align}\,\!

Rectifying latitude

• Rectifying latitude, , is the surface distance from the equator, scaled so the pole is 90°. Unfortunately, it involves elliptic integration:

 

Conformal latitude

• Conformal latitude, , gives an angle-preserving (conformal) transform to the sphere.

Failed to parse (unknown function\color): \chi=2\cdot\arctan\left(\sqrt{\frac{1+\sin(\phi)}{1-\sin(\phi)}\cdot\left(\frac{1-\sin(\phi)\sin(o\!\varepsilon)}{1+\sin(\phi)\sin(o\!\varepsilon)}\right)^{\!\!\sin(o\!\varepsilon)}}^{\color{white}|}\;\right)-\frac{\pi}{2};\;\!

Geocentric latitude

• The geocentric latitude, , is the angle between the equatorial plane and a line from the center of the Earth.

Comparison of latitudes

The following plot shows the differences between the types of latitude. The data used is found in the table following the plot. Please note that the values in the table are in minutes, not degrees, and the plot reflects this as well. Also note that the conformal symbols are hidden behind the geocentric due to being very close in value.

Approximate difference from geographic latitude ("Lat")
Lat	Reduced	Authalic	Rectifying	Conformal	Geocentric
0°	0.00′	0.00′	0.00′	0.00′	0.00′
5°	1.01′	1.35′	1.52′	2.02′	2.02′
10°	1.99′	2.66′	2.99′	3.98′	3.98′
15°	2.91′	3.89′	4.37′	5.82′	5.82′
20°	3.75′	5.00′	5.62′	7.48′	7.48′
25°	4.47′	5.96′	6.70′	8.92′	8.92′
30°	5.05′	6.73′	7.57′	10.09′	10.09′
35°	5.48′	7.31′	8.22′	10.95′	10.96′
40°	5.75′	7.66′	8.62′	11.48′	11.49′
45°	5.84′	7.78′	8.76′	11.67′	11.67′
50°	5.75′	7.67′	8.63′	11.50′	11.50′
55°	5.49′	7.32′	8.23′	10.97′	10.98′
60°	5.06′	6.75′	7.59′	10.12′	10.13′
65°	4.48′	5.97′	6.72′	8.95′	8.96′
70°	3.76′	5.01′	5.64′	7.52′	7.52′
75°	2.92′	3.90′	4.39′	5.85′	5.85′
80°	2.00′	2.67′	3.00′	4.00′	4.01′
85°	1.02′	1.35′	1.52′	2.03′	2.03′
90°	0.00′	0.00′	0.00′	0.00′	0.00′

Astronomical latitude

A more obscure measure of latitude is the astronomical latitude, which is the angle between the equatorial plane and the normal to the geoid (ie a plumb line). It originated as the angle between horizon and pole star.

Astronomical latitude is not to be confused with declination, the coordinate astronomers use to describe the locations of stars north/south of the celestial equator (see equatorial coordinates), nor with ecliptic latitude, the coordinate that astronomers use to describe the locations of stars north/south of the ecliptic (see ecliptic coordinates).

Palæolatitude

Continents move over time, due to continental drift, taking whatever fossils and other features of interest they may have with them. Particularly when discussing fossils, it's often more useful to know where the fossil was when it was laid down, than where it is when it was dug up: this is called the palæolatitude of the fossil. The Palæolatitude can be constrained by palæomagnetic data. If tiny magnetisable grains are present when the rock is being formed, these will align themselves with the Earth's magnetic field like compass needles. A magnetometer can deduce the orientation of these grains by subjecting a sample to a magnetic field, and the declination of the grains can be used to infer the latitude of deposition.

Further reading

• John P. Snyder Map Projections: a working manual excerpts

See also

• American Practical Navigator
• Cardinal direction
• Geographic coordinate system
• Geodetic system
• Geodesy
• Geotagging
• Great-circle distance
• Horse latitudes
• List of cities by latitude
• List of cities by longitude
• Longitude
• Navigation
• World Geodetic System

Footnotes

1. ^ Location, Location, Location. The relationship of climate to, and the effect of disease and agricultural productivity on, the economic success of a city or region.

References

• Beals, K. L., Smith, C. L. & Dodd, S. M. (1984). "Brain size, cranial morphology, climate, and time machines". Current Anthropology 25: 301–330. 
• Lynn, R. (1991). "The evolution of racial differences in intelligence". Mankind Quarterly 32: 99–173. 

External links

• libproj4: A Comprehensive Library of Cartographic Projection Functions (Preliminary Draft)PDF (1.88 MiB)
• Free GeoCoder
• GEONets Names Server, access to the National Geospatial-Intelligence Agency's (NGA) database of foreign geographic feature names.
• Look-up Latitude and Longitude
• Resources for determining your latitude and longitude
• Convert decimal degrees into degrees, minutes, seconds - Info about decimal to sexagesimal conversion
• Convert decimal degrees into degrees, minutes, seconds
• Latitude and longitude converter – Convert latitude and longitude from degree, decimal form to degree, minutes, seconds form and vice versa. Also included a farthest point and a distance calculator.
• Worldwide Index - Tageo.com – contains 2,700,000 coordinates of places including US towns
  • for each city it gives the satellite map location, country, province, coordinates (dd,dms), variant names and nearby places.
• Distance calculation based on latitude and longitude - JavaScript version
• Zoomable version of the mapPDF (3.42 MiB)nds-nl:Breedtegraodvls:Brêedtegroad

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - frihed, handlefrihed, spillerum, bevægelsesfrihed, råderum, bredde

Nederlands (Dutch)
speelruimte, vrijheid van handelen, ruimdenkendheid, geografische breedte, hemelstreek, astronomische breedte, omvang

Français (French)
n. - (Géog) latitude, marge, latitude

Deutsch (German)
n. - Spielraum, Freiheit, Breite

Ελληνική (Greek)
n. - γεωγραφικό πλάτος, πλάτος, εύρος, ελευθερία, ξεγνοιασιά, περιθώριο (κινήσεων), ευρυχωρία

Italiano (Italian)
margine

Português (Portuguese)
n. - latitude (f) (Geog.)

Русский (Russian)
широта, свобода суждений

Español (Spanish)
n. - latitud, amplitud, libertad

Svenska (Swedish)
n. - latitud, bredd, breddgrad, handlingsfrihet, rörelsefrihet, spelrum, utrymme, omfång, omfattning

中文（简体） (Chinese (Simplified))
纬度, 回旋余地, 自由, 纬度地区, 曝光宽容度

中文（繁體） (Chinese (Traditional))
n. - 緯度, 迴旋餘地, 自由, 緯度地區, 曝光寬容度

한국어 (Korean)
n. - 위도, 지방, 범위

日本語 (Japanese)
n. - 緯度, 地方, 黄緯, 範囲, 自由, 許容範囲, 寛容度

العربيه (Arabic)
‏(الاسم) خط العرض, منطقه, مدى, نطاق, حريه العمل أو الإختيار‏

עברית (Hebrew)
n. - ‮קו-רוחב, רוחב גיאוגרפי, חופש פעולה, מרחב, חירות ההבעה‬

If you are unable to view some languages clearly, click here.

To select your translation preferences click here.