GPS Smartphone navigation just got easier using Geospatial PDF, an extension to Adobe’s Portable Document Format that let’s you encode GPS features with PDF documents. Imagine being able to download a PDF map to your phone for a state park or ski resort and having the ability to find your location or map a track on it using your phone’s built-in GPS capability. This is easier to do today than you probably realize.
Below, I show you have you can use Caltopo (a web-based navigation planning tool) to self-publish a Geospatial PDF map and the free trial version of Avenza Maps, a Smartphone app available for the iPhone and Android, to plot your GPS position. You can transfer the PDF map to Avenza by attaching it to an email message and opening it directly into Avenza on your phone. It’s really easy, as I illustrate below. Caltopo and Avenza are not the only mapping and GPS tools that support Geospatial PDF, but the versions I use in the example below are FREE, so you can try them out.
Who else publishes GeoPDF maps? All current and historic USGS quads (the entire USA) are available for free. Your tax dollars at work!
Step 1: Create a Geospatial PDF Map with Caltopo.com
Open Caltopo.com and find an area near you using the search function. You don’t have to plot a route or anything. Print a map of the area, selecting the “Geospatial PDF” format in the upper left hand corner. This adds some geo-reference information to the PDF document. Position the red focus window over the area you want to turn into a PDF and click on the button on the bottom of the Caltopo.com screen that says “Generate PDF.” Caltopo will generate a PDF document that will open in another browser window. Save this document on your computer.
Step 2: Open the Geospatial PDF map attached to an email message in Avenza Maps.
Step 3: Open the map in Avenza and plot your current GPS position.
To plot your current position in Avenza, click on the leftmost icon on the bottom of the screen, which will display a blue dot (above) showing your current position. It’s as simple as that! The position function also works offline, even when your phone is not connected to a cell phone or data network.
Avenza has some other nice features that you can use with your PDF map, including the ability to record a GPS track on your PDF map. Check out the middle and right photo at the top of this post: they show the track of the route I took on a ski tour in the area of the map generated for this example.
Geospatial PDF and the Future of Map Publishing
Geospatial PDF has the ability to completely transform the map publishing landscape that we know today, making it possible to publish ‘smart maps’ that can determine your location when displayed on a smartphone. The fact that geo-data is encoded in the PDF file makes it truly portable between devices, unlike the maps published by Garmin, for instance, which will only work on their proprietary GPS units and in their proprietary planning and publication tools.
The availability of free map publishing tools like Caltopo that can generate Geospatial PDF means that individuals can begin to self-publish smartphone-enabled maps for sale or to share with friends. The possibilities are really endless and should herald a new era of smartphone-enabled map publishing.
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