GPS has come a long way since I first saw someone use a unit in 1992 on the crater rim of the Mt. Bromo volcano in Java, Indonesia. By 1995, we had a Garmin 45 while exploring a previously unvisited alpine valley near Koropun, New Guinea. At the time, the average error was still 30-100m, and the unit took a long time to lock onto 8 satellites simultaneously. But it worked, and showed us exactly how far we were from a friend’s house with cold beer.
I recently retired my trusted Garmin 12, which took me on an epic drive through the southeastern Gobi desert of Mongolia. It was a great unit, but lacked built-in maps. As a result I always knew where I was, but it was hard to pinpoint the location on a map. For the Gobi trip, I hooked up the unit to a laptop running scanned 1:100,000 Russian maps on OziExplorer. That worked very well, and allowed us to navigate through one of the most deserted parts of the Gobi without trouble (other than many flat tires!). The unit worked well, except in the forest. Not exactly a problem in the Gobi, but certainly an issue when trying to map hiking trails in the dense forests of Bhutan.
I now have a Garmin eTrex Vista HCx, which has mapping abilities. It allows you to upload any vector-based maps. The Garmin Mapsource 1:50,000 maps for Canada work well, but don’t have everything one wants on them. Bring in CGPSMapper, software that allows users to create their own Garmin maps from any vector-based data. It includes a map database, where users have uploaded their maps. Cool.
I find that even with a mapping GPS you need paper maps to get an overview, but you should have a map (and a compass!) with you anytime anyway in case the GPS dies on you.
One huge advantage of the new crop of GPSs is that they are much more sensitive, so they even pick up signals inside a house, or better yet, in the forest.
I don’t see detailed maps of Mongolia yet, though, so next time I drive through the Gobi (I’d love to visit the far southwest next time!), I’ll go the laptop route again. Still unbeatable compared to anything else out there.