![]() The Easting value of a UTM coordinate is expressed relative to the Central Meridian in the same way that the Northing is expressed relative to the Equator. All UTM Zones are subdivided down the middle by a Central Meridian assigned an Easting of 500,000 meters. This line is called the Central Meridian and is arbitrarily assigned an Easting of 500,000 meters. The East/West component of a UTM Coordinate, or the Easting, is expressed relative to an imaginary line that runs down the middle of each of the UTM Zones. So, if you were expressing a coordinate in the Southern Hemisphere that was 60,000 meters south of the Equator, that coordinate would have a Northing of 940,000 meters. But when giving a coordinate’s position south of the Equator, still refered to as the Northing, the Equator is assumed a value of 1,000,000 meters and the Northing for the coordinate is expressed as a positive value relative to the 1,000,000 meter Equator. It may sound strange but when specifying a coordinate’s position North of the Equator, or Northing, the Equator is assigned a value of 0 meters. The north/south component of the coordinate, or Northing, is expressed in meters relative to the Equator. Bands “I” and “O” are skipped to avoid confusion with the numbers 1 and 0 respectively.Ĭoordinates are given in Easting and Northing values expressed in meters. The system is further divided into 20 horizonal (East/West) bands that start at -80 degrees south latitude with band labeled “C” and ends north to +84 degrees latitude with band “X”. ![]() Thus, UTM Zone 1 begins at 180 Degrees West and extends east to 174 Degrees West. The Universal Transverse Mercator Coordinate System consists of 60 vertical (North/South) UTM Zones that start at the 180 degree longitude meridian and wrap around the Earth towards the East and are numbered 1 through 60. So I developed CGCUTMCoordinateCtrl and derived it from my new Multi-Field Edit Control class, CGCMultiFieldEdit, to provide a single control for entering and displaying UTM Coordinates.įirst, I’ll hit the high-points of the UTM Coordinate System. ![]() That, along with the increasing need to integrate GPS units (which typically provide UTM coordinates) with applications, made me think that a control for entering and displaying UTM Coordinates would be useful to keep around. There are many applications today that utilize some form of mapping capability. Many maps come with both a Latitude/Longitude grid for a given datum/ellipsoid as well as a Universal Transverse Mercator (UTM) grid to determine coordinates. This article was contributed by George Chastain.
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