Universal Transverse Mercator projection (UTM)
The Universal Transverse Mercator projection (UTM) is a projection that was created by the U.S. military; however, UTM is used by many professional civilians. The projection is based on the Mercator projection, but as the name implies, it is transverse rather than based on a Equatorial aspect. [1] UTM is a system which divides the world into 60 equal zones, each zone is 6 degrees wide. UTM "covers the earth's surface between 80 degrees South and 84 degrees North".[2]Zone 1 starts at 180 degrees west and goes to 174 degrees west. Every zone is a unique projection. All the projections are transverse Mercator, but they are secant to different central meridians. The central meridian for each zone is located in the center of the zone. For example, the central meridian for zone 1 (180 degrees west to 174 degrees west) is 177 degrees west.[3]
Because each zone is based on a different central meridian, you cannot accurately place maps of 2 different zones together. This may seem very inconvenient, and it is, but the UTM system is very accurate for within zone purposes. Positions are found using an easting and a northing. The area with a easting value of 0 and the northing value of 0 is called the point of origin. All measurements are made in relationship to the point of origin. The northing is a measurement in meters from the equator. The easting is slightly more complicated. Every zone has its own easting, which is always 500,000 meters west of each zone's central meridian.[4] UTM coordinates are easy to recognize because they consist of a zone number, a six-digit number (easting), and a 7-digit number (northing). An example would be "zone 12 450980 mE 4500540 mN."[5]
Sources
- ↑ Longley, Paul A. et al, Geographic Information Systems and Science(2005), 2nd Edition
- ↑ Campbell, John. Mapu Use & Analysis. p 55.
- ↑ Longley, Paul A. et al, Geographic Information Systems and Science(2005), 2nd Edition
- ↑ http://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system
- ↑ Longley, Paul A. et al, Geographic Information Systems and Science(2005), 2nd Edition
| Authors | Carson |
|---|---|
| Editors | Thalassa Jones |
| BoK Topics | CV2, GD5 |
| 311 Weeks | 7 |
| Tags | UTM, projections |
