Create a UTM Map

The Universal Transverse Mercator (UTM) system divides the world into a regular, nonoverlapping grid of quadrangles called zones. Each zone is 8-by-6 degrees in extent and uses a transverse Mercator projection that is designed to limit distortion. UTM zones are identified using a grid reference in the form of a number followed by a letter, for example 31T. Each UTM zone has a false northing and a false easting. These are offsets that enable each zone to have positive coordinates in both directions. All UTM zones have a false easting of 500,000 meters. All zones in the northern hemisphere have a false northing of 0 meters, and all zones in the southern hemisphere have a false northing of 10,000,000 meters.

The UTM system is defined between 80 degrees south and 84 degrees north. Beyond these limits, use the Universal Polar Stereographic (UPS) system instead. The UPS system has two zones, north and south. Both UPS zones have a false northing and false easting of 2,000,000 m.

Create a UTM Map

You can create UTM maps with the axesm function. However, unlike other projections, the map frame is limited to an 8-by-6 degree map window (the UTM zone).

Create a UTM axesm-based map.

axesm utm

Get the properties of the axesm-based map and inspect them in the Command Window or with the Variables editor. Note that the default zone is 31N. This is selected because the map origin defaults to [0 3 0] , which is on the equator and at a longitude of 3° E. This is the center longitude of zone 31N, which has a latitude limit of [0 8], and a longitude limit of [0 6].

h = getm(gca);
h.zone

ans = 
'31N'

Change the zone to 32N, one zone to the east of the default, and inspect the other parameters again. Note that the map origin and limits are adjusted for zone 32N.

setm(gca,'zone','32n')

h = getm(gca);

Draw the map grid and label it.

setm(gca,'grid','on','meridianlabel','on','parallellabel','on')

Load and plot the coastline data set to see a close-up of the Gulf of Guinea and Bioko Island in UTM.

load coastlines
plotm(coastlat,coastlon)