[driggs]

This page actually points out a minor frustration that I frequently experience with UTM in GIS software and GPS receivers, under the "MGRS grid row designators".

These MGRS row designators are completely optional and redundant, because a UTM northing values span the entire Y dimension of a Zone.

What is not redundant is the hemisphere designator, "N" or "S".

There are 20 row designators, and the designers excluded the letters "I" and "O" to avoid confusion with the visibly-similar numbers "1" and "0". There are 26 letters in the alphabet to choose from, but they did not bother to exclude the letters "N" or "S".

It just so happens that the row which covers half of the continental United States - which is in the Northern hemisphere - is the row labeled "S".

So well-meaning GIS software and even Garmin GPS receivers often call my zone "17S", which reads as "Zone 17, Southern Hemisphere". My zone is in fact "17N", "Zone 17, Northern Hemisphere". This is especially annoying given that the row label is an artifact of MGRS and not civilian UTM.

http://www.mibsar.com/LandNav/UTM/UTM.htm#Rows

[chipsa]

You are in MGRS zone 17S. MGRS also has grid square designations after the zone, and before the easting/northing numbers. A full UTM coordinate string will only have N/S at position 2/3, while a full MGRS coordinate string will have 3 characters at that position. A MGRS string will also be 2 characters shorter than an equivalent UTM string.

Civilian UTM doesn’t handle things near the poles very well. MGRS explicitly uses the zone characters to change to a polar projection. Those other 4 characters not used for row identification actually identify polar areas (NE, NW, SE, SE semi-hemispheres).

[Waterluvian]

In undergrad we made a habit of saying and writing “North” or “South” because of this confusion.

(Also: Zone 17T represent!)