Latitude vs. Longitude

Main Difference

The main difference between Latitude and Longitude is that the Latitude is a the angle between zenith and a plane parallel to the equator and Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth’s surface

• Latitude

  In geography, latitude is a geographic coordinate that specifies the north–south position of a point on the Earth’s surface. Latitude is an angle (defined below) which ranges from 0° at the Equator to 90° (North or South) at the poles. Lines of constant latitude, or parallels, run east–west as circles parallel to the equator. Latitude is used together with longitude to specify the precise location of features on the surface of the Earth. On its own, the term latitude should be taken to be the geodetic latitude as defined below. Briefly, geodetic latitude at a point is the angle formed by the vector perpendicular (or normal) to the ellipsoidal surface from that point, and the equatorial plane. Also defined are six auxiliary latitudes which are used in special applications.

• Longitude

  Longitude (, AU and UK also ), is a geographic coordinate that specifies the east–west position of a point on the Earth’s surface, or the surface of a celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians (lines running from pole to pole) connect points with the same longitude. By convention, one of these, the Prime Meridian, which passes through the Royal Observatory, Greenwich, England, was allocated the position of 0° longitude. The longitude of other places is measured as the angle east or west from the Prime Meridian, ranging from 0° at the Prime Meridian to +180° eastward and −180° westward. Specifically, it is the angle between a plane through the Prime Meridian and a plane through both poles and the location in question. (This forms a right-handed coordinate system with the z-axis (right hand thumb) pointing from the Earth’s center toward the North Pole and the x-axis (right hand index finger) extending from the Earth’s center through the Equator at the Prime Meridian.)

  A location’s north–south position along a meridian is given by its latitude, which is approximately the angle between the local vertical and the equatorial plane.

  If the Earth were perfectly spherical and radially homogeneous, then the longitude at a point would be equal to the angle between a vertical north–south plane through that point and the plane of the Greenwich meridian. Everywhere on Earth the vertical north–south plane would contain the Earth’s axis. But the Earth is not radially homogeneous and has rugged terrain, which affect gravity and so can shift the vertical plane away from the Earth’s axis. The vertical north–south plane still intersects the plane of the Greenwich meridian at some angle; that angle is the astronomical longitude, calculated from star observations. The longitude shown on maps and GPS devices is the angle between the Greenwich plane and a not-quite-vertical plane through the point; the not-quite-vertical plane is perpendicular to the surface of the spheroid chosen to approximate the Earth’s sea-level surface, rather than perpendicular to the sea-level surface itself.

• Latitude (noun)

  the angular distance of a place north or south of the earth’s equator, or of the equator of a celestial object, usually expressed in degrees and minutes

  “lines of latitude”

  “at a latitude of 51° N”

• Latitude (noun)

  regions, especially with reference to their temperature and distance from the equator

  “temperate latitudes”

  “northern latitudes”

• Latitude (noun)

  scope for freedom of action or thought

  “journalists have considerable latitude in criticizing public figures”

• Latitude (noun)

  the range of exposures for which an emulsion or printing paper will give acceptable contrast

  “a film with a latitude which is outstanding”