GPS Contour Maps for Ireland



By Brian Kelly (Original article 2006)


GPS Overview

GPS technology means that it's possible for anybody with a GPS unit to obtain an extremely accurate (often within ±10m) reading of their position. Overlay that position on a detailed map, build in a compass and altimeter, add some functionality to record tracks, mark waypoints etc. and you've got a device that should be an invaluable aid to the hillwalker.

The key to its usefulness is the quality of the map.

A map with little or no detail means that the GPS unit by itself is close to useless when navigating (other than when tracking back along a trail already walked). In order to navigate the user will have to regularly take a grid reference from the GPS unit and locate that position on a paper map.

On the other hand, a sufficiently detailed map on the GPS unit should in most circumstances eliminate the need to refer to a paper map (although you should always have one with you for backup (see safety warnings)). In such a situation navigating becomes a whole lot easier. In simplistic terms navigation consists of figuring out

  1. Where you are
  2. Where you're going to
  3. How you're going to get there
A GPS unit with a sufficiently detailed map automatically performs the first task for you, and gives a lot of help with the second and third.