Review of Avenza’s PDF Maps app for iPhone and iPad

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This app gets the job done: PDF Maps introduces a strongly played set of basic features and later versions promise to add more advanced features like layer visibility and feature attribute query. Professional cartographers can use the app to deliver custom cartography maps that leverage GPS to locate the map-reading customer with the magic blue dot. It’s certainly not an ArcPad, but it works on the iPad and you’ll find it fun to use (and the app price is right).

I quite enjoy Avenza’s new free PDF Maps iOS app, free and available now on the iTunes App Store for iPhone and iPad. I’ve been testing it for several months using both the beta and  final release versions. I’ve used the app in my neighborhood, on a cross country road trip, and we’ve been using it to ground truth maps at at my day job. I’ve created my own GeoPDFs and used those from USGS and Avenza.

Besides myself, I setup two non-cartographers with an iPad (3g  with gps) and several GeoPDFs depicting neighborhood-level street maps to field check in the Washington DC metro area. They were amazed at how easy it was to locate themselves on the map and make notes by dropping markers they bring back to the office for me to review. Because these particular maps include street labels, they don’t need to switch back and forth to Apple’s provided Google Maps app as they navigate.

The inaugural version is iOS only but the company has had requests for Android, Symbian, Blackberry and even Windows 7 Mobile. Expect an Android version next. Future iterations of the app may introduce a two-tiered, free-basic feature and pay advanced feature parellel versions, which seems reasonable to me. I’m also excited to see if a white-label version becomes available (much like the Flash SWF export out of Avenza’s MaPublisher plugin for Illustrator) that cartographers can use to brand the experience and pre-bundle their maps.

PDF Maps offers the following capabilities:
  • View and load your own custom cartography maps and view them with GPS location
  • Supports both Adobe/ESRI geospatial PDF maps and TerraGo/USGS GeoPDF® files.
  • Access and interact with saved maps without the need for a live network connection
  • Standard GSP app features: Plot way-points, enter attribute data and notes, measure distances and areas
  • Standard iOS interface: Quickly view, zoom and pan maps using gestures (pinch, drag and flick, double tap)
  • HD version for iPad same app as the basic version for iPhone, slightly reworked interface
  • Does not currently support waypoint export, a key feature
  • Does not currently support import of KML and GPX files

To create a GeoPDF, you’ll need ArcGIS 9.3.1+ to export from ArcMap with preserve coordinate system checked. Or use Avenza’s MaPublisher plugin for Illustrator (version 8.2+). You can also download thousands of GeoPDFs from USGS. Even though the USGS files use the TerraGo GeoPDF format specification (versus Adobe + ESRI’s), it will open and render in PDF Avenza also offers dozens of sample GeoPDFs linked from within the app to get you started (click Maps, then +, then From Avenza PDF Maps Library and browse the list).

Adding maps is as simple as dragging them to iTunes or attaching to an email (making it easy to send map updates to your field checker). Clicking on a PDF link on the iPhone or iPad now prompts to open in the app, as seen in the first screenshot above . Once opened in the PDF Maps app, it will take a few seconds to minutes to render, second screenshot above. Once open, several tools are available, the most important of which is simply the “locate me” triangle button on the map map view.

Even though it’s all about the PDF map you’re looking at, the app makes it convenient to open the same view in to see Google’s version of reality for cross checking, especially using the satellite map tiles there. This is possible for both the current map view using the tools menu, and to open a specific waypoint marker after clicking it’s location field.

I’ve loaded PDFs with the app that are more than 10 mb of vectors and performance has been good. When the map first loads it will process and prepare several zoom levels of precached tiles. This will make panning and zooming faster during actual map use and is worth the wait.

During precache rendering, you can still use the map, but the parts that will still be loading will be fuzzy for a while. Very large maps (larger than 20 mb, or more than 2000 sq. inches) are slower to render in this version (hey, it’s a mobile phone). For larger areas, I’ve been splitting the exported map into separate files. When multiple maps loaded in, there is a Maps table of contents listing.

I found a couple continuing quirks with the app and one major missing feature. The app really needs to export the map’s waypoints as CSV, KML, and GPX as an email attachment. I wish repositioning an existing pin was easier. The hit areas on some buttons is small, making it hard to use in a moving car. Sometimes it’s nice to have multiple marker icon labels open, but sometimes that is odd. At any rate, there’s no way to close them all en mass.

Quick and dirty test GeoPDF files:
(using Natural Earth, US Census, and other draft data)

Note: Because of USGS website quirks, it is not possible to directly download a USGS GeoPDF onto your iPhone/iPad in the field. The website doesn’t render properly (something about IE and cookies), and the resulting download file is ZIP format rather than PDF. Not sure why, since the PDF should already be optimized for file size (there’s only a 1.5% file size savings between ZIP and PDF in the Washington D.C. West quad sheet).

Check out more screenshots:

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