Using GPS as a Travel Aid
A Handheld GPS Unit Can Help Scout Out the Route On the Ground
Global Positioning Satellite (GPS) and related systems can be used to navigate, to record the details of a journey, and to see in advance what the terrain will be like.
GPS stands for Global Positioning Satellites or Global Positioning Systems. The satellites up in the sky send signals down to earth and with a hand-held receiver - commonly called a GPS, or a GPS unit, anyone can record their own precise location here on the planet Earth. In conjunction with GIS, or Geographic Information Systems (what we used to called "computer-based mapping" in the olden days), GPS can be a great travel aide.
The GPS units in some new cars are an example of how the GPS technology helps in navigation. In a car, the usual situation is that you enter in the address of the place you want to get to, and the onboard computer displays a map and speaks directions to you.
With a handheld GPS unit, you carry the GPS with you. They vary in size but are generally like a telephone receiver or smaller. As long as you can receive the signals of at least three satellites, your GPS unit can track your every step. The accuracy varies, but it can be within a couple of metres.
GPS doesn't work as well in urban areas, as the tall buildings tend to block some of the satellite signals. However, it is still useful and with a little patience, a user can figure out how to make the best of an urban situation.
If you carry a GPS receiver around all day, at the end of your journey, using a cable that comes with the GPS unit, you can download the data onto your computer and display it on the computer's screen. The typical way of doing this shows up as a map view, where your track shows up either as a wiggly line on an empty screen, or (which is much more interesting) as a track mapped onto an existing detailed base map. It's as if you took a pencil and drew your exact journey onto a paper map.
Another view is the vertical one: how did the elevation change as you went along? This view shows a profile of your trip, rather than the map view.
There are a few ways in which this sort of information is useful.
First, some GPS units are pre-loaded with base maps, and some can have additional maps loaded onto them. This makes the unit ready to use as a navigational aide.
Next, if you use the GPS to track your daily travels, you end up with an excellent memory aide, trip log, and diary all in one. At the end of the day, you can make notes on the map of your journey. You can remember all the little side detours that tend to fade from one's mind when in an unfamilar place.
And, if you have someone available to scout the path for you, you can assess whether the distance and gradient are suitable. Of course, this can be done with a topographic map. However, there are so many GPS users now, and such excitement in the on-line world over the ability to use maps and geographic information, that the paper topographic map is becoming a second choice.
Imagine going to a website, posting a request for someone to walk a route for you, and having them in turn post exactly the details you need for planning? If you have mobility or other limitations, you could figure out beforehand how you would get around.
Or how about a website with routes already mapped and commented on?
We are 99.9% of the way there, thanks to GPS and the fantastic developments in GIS (Geographic Information Systems) for personal use by ordinary folk. There are a number of websites incorporating Google Earth, and many people have posted comments about places all over the world. It's the renaissance of mapping, without the need to learn how to use an astrolabe.
