The Happy Camper: Understanding the Universal Transverse Mercator (UTM)
The Universal Transverse Mercator (UTM) is a grid system developed by the military during World War II to be more accurate during an artillery bombardment. It’s a much more precise system for locating areas on a map than the traditional latitude and longitude system, especially when using a GPS. The Global Positioning System shows coordinates in both, but most people will just know of the latitude and longitude.
The UTM system divides the earth into 60 zones (numbered 1-60), each zone being six degrees wide and goes from 80 degrees south latitude to 84 degrees north latitude. The lines don’t converge like longitude and latitude lines. UTM lines remain as a rectangle, which is the main reason they are far more user friendly.
Understanding the complex looking UTM numbers seems a little overwhelming at first. After a few tries at it though you’ll soon get the hang of it. The numbers along the sides of the topographical map represent the “northern” coordinates and “easting” coordinates; the northern denoting how many meters the position is from the equator and the easting denotes how many meters the position is away from the zone’s longitudinal origin. Remember, when rambling off coordinates the easting comes first and the northern comes second. “Start in the basement and then walk up the stairs” is a good way to remember this.
Watch my KCHappyCamper You Tube video on how to use the UTM system on a topographical map.
