Walking and GPS
GPS systems designed for walkers, trekkers and mountaineers have really taken off in the last 10 years with colour screens, precise positioning and more and more complex tools. So what are they and how do they work?
This article is an overview of GPS technology. GPS stands for global positioning system and is a system of localisation by triangulation using satelites. A GPS system works by using a receptor which captures and interprets information provided by satelites, allowing the GPS to calculate its position on the ground. Triangulation allows the machine to provide the latitude, longitude and altitude of its position. Its precision depends on the number of satelites employed to calculate the information. Today most GPS tools have an accuracy of between 50m and 10m depending where you are, which is usually accurate enough for use by walkers on walking tours or independent walking holidays.
A GPS system is certainly a useful and fun new device with regards to navigation in the hills and mountains whether in the UK or France. However, a thorough knowledge of map reading and compass skills is essential before you can take on the extra challenges of a GPS system.
Of course on our guided walking holidays our experienced leaders will take care of finding the way so you can relax and enjoy the views. In addition, on our low altitude self-guided walking holidays (i.e. not those in mountain or remote terrain) our detailed walking notes allow you to find your way with ease, with only basic navigation and map reading skills being required. In addition the walking trails on our walking holidays follow footpaths and quiet roads the whole time.
So what are digital maps? Digital maps are simply electronic versions of the maps you can buy on paper. The 1:25,000 walking maps produced by IGN in France and the Ordnance Survey in the UK are all available in digital formats for your computer or mobile device. In order to view the maps you'll need to use software which you usually purchase from the same supplier as the maps. Using digital maps allows you to scan from one map area to another on the screen (provided you have bought both map areas) and to draw your chosen walking route on the map. When you draw a walking route on the digital map the software will inform you of the distance and amount of ascent and descent. This information can then be uploaded onto your mobile device or GPS or you can print out parts of the maps, as you'll still need a map to follow when you're out walking.
What does a GPS give you that a paper map cannot? As well as the positioning mentioned earlier, it can also tell you the time taken between points, your speed, the bearing you're walking on and altitude above sea level. It is advisable to get a GPS which works with the detailed walking maps at 1:25,000 in scale.
Once you've got a model (making sure that it works with your software on your computer and that you can upload and download routes), before you go out for a walk make sure you know the basics of the device such as drawing your route and making sure it's suitable for your abilities and plotting waymarks. It is a good idea to always have a paper map and compass with you so that you can fall back on traditional navigation if needed.
How to use your GPS? To set up your GPS for your walking route you have two basic options. The first is to manually insert the coordinates of many points of your intended route into your GPS, using the paper map to select suitable points along your walking route. It is important using this method to choose appropriate waypoints and to accurately feed in the information. Any errors in the coordinates will cause problems along your walk.
The second is to mark the route on a digital map on your computer and then download the route to your GPS. You should choose a number of waypoints on your route, for example at major changes in directions or at the start of ascents or descents. Once you are out walking your GPS will then be able to show you your position, your direction, your route and depending on your model, an onscreen map.
Most GPS systems then allow you to record your walking route as you go along, so that you can upload your walk to your digital mapping system when you get home.