Posted by ramel nortega

Latitude

Further information: Latitude

The latitude of a place on the earth's surface is the angular distance north or south of the [equator].Latitude is usually expressed in degrees (marked with °) ranging from 0° at the Equator to 90° at the North and South poles.The latitude of the North Pole is 90° N, and the latitude of the South Pole is 90° S.Historically, mariners calculated latitude in the Northern Hemisphere by sighting the North Star Polaris with a sextant and sight reduction tables to take out error for height of eye and atmospheric refraction. Generally, the height of Polaris in degrees of arc above the horizon is the latitude of the observer.

Longitude

Further information: Longitude

Similar to latitude, the longitude of a place on the earth's surface is the angular distance east or west of the prime meridian or Greenwich meridian.Longitude is usually expressed in degrees (marked with °) ranging from 0° at the Greenwich meridian to 180° east and west. Sydney, Australia, for example, has a longitude of about 151° east. New York City has a longitude of about 74° west. For most of history, mariners struggled to determine precise longitude. The problem was solved with the invention of the marine chronometer. Longitude can be calculated if the precise time of a sighting is known.