Why use a computer and a Global Positioning System (GPS) receiver to plan, record, and share your excursions? In a nutshell: accuracy, thrift, and customization. In Using a GPS: Digital Trip Planning, Recording, and Sharing ($13, falcon.com), excerpted here, Bruce Grubbs shows you how to plot your own digital adventures with precision—then print the maps and prep your GPS.
Download a Trip
The easiest way to plan any hike (or paddling or backcountry ski trip) with GPS is to download waypoints, routes, and track data (a trail of automatically saved breadcrumbs dropped along your route) from an online trip database to your computer. You can find GPS info on several commercial sites or, better yet—shameless plug—on free sites such as backpacker.com, which has thousands of editor-approved trips. From dayhikes to long thru-hikes, from Acadia to Zion, these trips are ready for immediate navigation.
Check the File Format
Data downloaded from the Web is usually in a GPX (GPS eXchange Format) file format. Geocache data is in LOC (localizer) format, and digital maps have their own format, such as National Geographic’s TPO or DeLorme’s TPX. GPS units commonly come with software for your computer that lets you read GPX and LOC files and save them to your GPS (as well as upload files from the GPS to the computer). Need to change the format to make it compatible with your setup? Free programs, such as EasyGPS (easygps.com) and GPS Babel (gpsbabel.org), will convert between myriad GPS file formats. Tip: Use a GPS-enabled smartphone with a navigation app, like BACKPACKER GPS Trails (backpacker.com/apps), and download data directly to the phone, skipping the computer entirely.
Do a Sanity Check
Since so many sources of GPS trip data exist (some of dubious accuracy), always check on the digital map whether the route makes sense: Does it lead you over a cliff or in circles? Compare the data to other information, such as guidebook descriptions, information from rangers and hikers who’ve done the trip, and online reviews of the trip report itself.