Longitude

Longitude is the measure of the geographical distance from a point on the earth's surface to the reference or prime meridian, the Greenwich meridian, symbolized by lambda. Latitude and longitude are the two angular distances—using either degrees, minutes, and seconds, or decimal degrees—in the geographic coordinate system that precisely communicate the position of a certain location, and their measurement is fundamental for mapping representation and navigation.

Longitude is an angle formed by the meridian plane that crosses a location on the earth's surface, the center of the earth, and the Greenwich meridian plane. Longitude values range from 0 degrees and 180 degrees to the east of Greenwich, expressed as a positive angle, and from 0 degrees and 180 degrees to the west of Greenwich, expressed as ...