Easting and northing
The terms easting and northing are geographic Cartesian coordinates for a point. Easting refers to the eastward-measured distance (or the -coordinate), while northing refers to the northward-measured distance (or the -coordinate). The orthogonal coordinate pair are commonly measured in meters from a horizontal datum. This simple cartographic convention comes from a methodology for determining coordinates and areas, known as the method of latitudes and departures. Eastings are the coordinates that stretch along the bottom -axis on the map while northings stretch along the side -axis.
When using the Universal Transverse Mercator coordinate system, northing is the distance to the equator, while easting is the distance to the "false easting", which is uniquely defined in each UTM zone.
The term northing has also been used by explorers to describe a general progress toward the North Pole. Isaac Israel Hayes used this term in a 1861 address to the New-York Geographical and Statistical Society saying, "The want of steam power curtailed my northing."
Notation and conventions
Coordinates for locations are provided using two sets of numbers on a simple Cartesian coordinate system. This way, locations can be found using easting/northing (or x,y) pairs. As a convention, the pair is typically represented easting first, northing second.
For example, the peak of Mount Assiniboine (at 50°52′10″N 115°39′03″W / 50.86944°N 115.65083°W) in UTM Zone 11 is represented by
11U 594934 5636174. Other conventions can also used, such as a truncated grid reference, which would shorten the example coordinates to
The linear value added to all x-coordinates of a map projection so that none of the values in the geographic region being mapped are negative. The point of origin of each UTM zone is the intersection of the equator and the central meridian of each zone. To avoid dealing with negative numbers the central meridian of each zone is set at 500,000 meters East.
The linear value added to all y-coordinates of a map projection so that none of the values in the geographic region being mapped are negative. the northing at the equator is set at 10,000,000 meters so no point has a negative value.
- ↑ ARCTIC EXPLORATIONS.; Lecture of Dr. J.S. Hayes before the New-York Geographical and Statistical Society. DR. HAYES' REPORT. The New York Times (November 15, 1861).
- ↑ "Truncated Grid References". Bivouac.com - Canadian Mountain Encyclopedia. 2006-11-17. http://www.bivouac.com/PgxPg.asp?PgxId=155.