Tuesday, July 05, 2005

Show Me Where: Mapping Hacks


I'm an avowed fan of O'Reilly's Hacks books, and familiar with the theme: software links and code-sets to help you get the most out of a particular computer application. Usually much of the excitement and imagery is mental, and you need some visualization skills to "see" what will result before you actually try a hack.

For that reason, I was totally unprepared for the sheer beauty of Mapping Hacks, which provides "tips and tools for electronic cartography." To start with, the book, written by Schuyler Erle, Rich Gibson, and Jo Walsh, is sumptuously illustrated. Hundreds of full-color photos and maps are scattered throughout the pages.

What hasn't changed is the organization; like other Hacks manuals, Mapping Hacks is a collection of mostly stand-alone explorations into cartography, the visual telling of compelling stories about the where of things. Every story has a place, the authors explain in the introduction, and cartography combined with geography is the means for effectively communicating that tale.

Then there are the hacks themselves. Even someone who has never considered a map as anything other than a nuisance to refold on a road trip will find something here to delight. We have hacks for mapping our lives, our neighborhood, our world, for mapping on the Web, with gadgets, and on your desktop. Sections also cover hacks for discovering names and places online, building the geospatial web, and mapping with other people.

You may not think you're into mapping, but consider Hack #7: "Will the Kids Barf?" This builds on a previous hack (#5, "The Road Less Traveled By in MapQuest") to calculate the queasiness factor of a curvy road. You'll know before you take off on that road trip whether to pack the Dramamine or not!

Or look at Hack #18, "Why You Can't Watch Broadcast TV." This walks you through the process of calculating the "viewshed" (the areas on a map which are not in a broadcast "shadow") for any spot in the U.S., using the U.S.G.S. digital elevations models available for free. To create viewshed maps for other areas, the authors refer us to Hacks #64 and #74, and a piece of software called GRASS, which can accept GPS input for several wonderful applications.

In "Mapping Your World," Hack #22 will amuse your kids as they begin their map explorations. Titled "Digging to China," this hack outputs PostScript images that plot the opposite point on the globe from a chosen starting point. Iif you dug through the center of the Earth from San Francisco, in the illustrated example, you'd have a hole full of water—the opposite point is in the middle of the South Pacific. This section also has marvelous hacks for playing with different map projections, plotting great-circle routes on various projections (cylindrical? think about it), and rendering topographic maps into landscape images, among others. You can even map other planets!

Not all these hacks are about about making or playing with maps. In "Mapping (On) the Web," Hack #36 shows us how to "Shorten Online Map URLs" using free Web services. Hack #38 gives step-by-step directions for adding GPS location info to your blog or RSS feed—specific hacks for Movable Type and Radioland are included.

As for playing with maps, you won't want to miss Hack #43, "Map Earthquakes in (Nearly) Real Time." This hack uses newly-available machine-readable data from U.S.G.S. RSS feeds to plot earthquakes at almost the same time as they occur. Yum!

Even more delicious are the gadget hacks. The wide availability of GPS-enabled devices provides a wealth of location data that cries out for application. From simple hacks like getting maps on your mobile phone (even if it's not GPS-capable), and accessories for your GPS device, the authors go on to cover converting GPS location formats, downloading to create trace logs using your GPS data, and (Hack #62) building a car computer for GPS navigation, a "project that will consume all your time and money, but make you the envy of your nerd friends."

Chapter 6, "Mapping on Your Desktop," gets into a truly map-obsessed terrain. Several high-power applications are discussed, all of which will allow you to produce densely-informative maps using online or GPS-derived data. (Hack #64, for example, introduces GRASS, which allows topographic data from anywhere in the world to be assessed for landforms. This allows you to evaluate broadcast shadows, among other applications.) From this point forward, the hacks address the sliver of the populace committed to creating and interpreting location plots. For example, Hack #79 tells us how to "Geocode a U.S. Street Address." Why? To enter it into your home-made car computer, of course!

Whether you're interested in maps at slightly more than a "how do I get there?" level, or professionally involved with plotting locations and geographic distributions, Mapping Hacks has something in it for you. All 100 hacks are intriguing, and several generate results that are simply stunning. This is the computer wonk's version of a coffee-table book, beautiful and built for browsing.

Please join us at BlogCritics to comment on this review.