Title: What are grid and coordinates systems
Headings: Map Reading – What are grid and coordinates systems?
Map Reading – What are grid and coordinates systems?
Coordinate Systems
Geographic Coordinate Systems (GCS)
Universal Transverse Mercator (UTM)
A couple more points
Wrap up

Content: That means that the same coordinates, used on maps that show different GCS will result in an up to 200m error. If you think this is not relevant for you, move on, if it is, stay with me for a little longer. Datum means a single data (just for your knowledge) and in geodesy (science of mapping) it means the shape and size of earth. There are hundreds of data, as different measurements have been made to earth (starting in the 1700s), but for mapping we are only going to focus on horizontal datum (on the surface). The datum is a reference point for the GCS grid to “place” the longitude and latitude lines). The one most commonly used is the WGS84 (World Geodetic System, updated at 1984), while in the USA you can find NAD83 (North American Datum 1983) and in the UK, OSGB36 (Ordinance Survey of Great Britain 1936). All three GCSs are very similar, so not much of a problem there. The data are just a reference point to keep an eye on if you are in a less surveyed area. From all this you can see that the GCS is a very complicated system, so luckily for us, most of the mapping on the planet moved to a much simpler system, UTM: Universal Transverse Mercator (UTM)
The UTM system is based on a basic concept of meractor projection: ‘