Brain Candy #96 - Where Are We?

by Brian Rock  8-05 -  E Central Ohio Mensa’s Braegen newsletter

One of the things I wanted to have, but didn’t, when we made our recent trip to Las Vegas, was a GPS receiver. If you’re not familiar with them, GPS stands for global positioning system - a way to use satellite signals to accurately establish one’s location. You can find out quite a bit more about the general topic from Wikipedia at en.wikipedia.org/wiki/GPS.

I’d been watching for a particular unit to come on the market, but it didn’t happen in time for the trip. When we got back, the model I was watching ontinued to be “Coming soon,” for an unreasonable period in my opinion. While I was waiting, I popped into Dick’s Sporting Goods one Saturday to see if they carried GPS receivers and found that not only did they, but they carried remanufactured units at a very good price. I walked out with one, and there the experiment began.

Its first major usage was when Catherine had a conference in Kalamazoo and I tagged along. Now we would have found Kalamazoo without it, even though I’d never been there before, but it did keep us from a wrong turn or two getting there.

In the urban environment of Kalamazoo, even with the proper mapping software, it seemed to be a mixed blessing. Once the batteries died at an inopportune time and a few times it suggested unlikely or confusing routes. It did much better when I went in search of some Michigan wineries, helping me find some in suburban and semi-rural locations. These places are often difficult to find due to the propensity of various jurisdictions to give multiple names to rural roads (eg “County Road 549” versus “Heehaw Lane”). If you’ve got the wrong name, your paper map doesn’t help much.

While I investigated how best to use my GPS, I found a lot of related cartography information that might interest you. One can use a GPS to play the games called geocaching and geodashing. Geocaching is concerned with using a GPS to find semi-hidden objects, while geodashing focuses on finding places with a GPS. I’ve not done any geocaching, but I have done a bit of geodashing. If you go to geodashing.gpsgames.org, you can find a website devoted to geodashing. Each month they run a game with a world-wide sprinkling of points to search for. For the current July 2005 game #49, there are 31,731 points scattered across the whole planet. The closest one to us in West Akron, designated “GD49-COAT”, is about 16 miles away as the crow goes, on the west side of Ravenna, Ohio. The farthest, “GD49-VUGO”, is 11,420 miles away, near Prevelly, Western Australia. It looks like there are about thirty points randomly dispersed around Ohio this month. One point, “GD49-CLAY”, near Wooster, has already been visited as I write this in early July. A geodasher nicknamed “epondo,” who I happen to know from work, has posted three pictures and a text description of the spot.

The way the game works, players score points by getting within 100 meters of a location. Since the locations are randomly chosen, some are not achievable without going onto private property. Trespassing is highly discouraged, being both rude, dangerous, and of course, illegal. It’s ok to ask for permission to access such a site, but imagine explaining what you’re about to someone unfamiliar with GPS units, internet games, etc. A geocacher or geodasher needs to be aware that to an uninformed observer, your conduct might look rather suspicious. Suspicious behavior brings rapid attention in some places these days.

Even if you don’t want to geogame, the geogames site is a great place to get acquainted with some really interesting geographic tools. Let’s use the “GD49-COAT” point for an example. You can navigate the game #49 map to find the point’s map page, but I’ll make it easy for you by giving you a direct link: geodashing.gpsgames.org/cgi-bin/ dp.pl?dp=GD49-COAT. You’ll see some info about the general location of the point, including a small map. Near the top, there’s the word “Maps” in blue - if you click on it, you’ll get a bunch of map-oriented resources that you can use to explore the location of the point in greater detail. I favor “Marky’s Terraserver Viewer” (www.yvanovich.com/terraserver/) and “LostOutdoors” (www.lostoutdoors.com) for US locations, but some of the other links offer unique tools that can be used for investigating places. Marky’s shows pretty clearly, via its topographic map of the site and an aerial photo, that it’s probably not a good candidate for a visit. It’s between some railroad tracks and near a strip mine. I would guess that it is a commercial property, perhaps with hazardous terrain - not a promising place for a visit.

If you like what you’ve seen so far, you might want to check out a new O’Reilly book called Mapping Hacks. It’s subtitled “Tips & Tools for Electronic Cartography”. The hundred hacks vary from the simple (Hack #3 - “Map the Places You’ve Visited”) to the exotic (#31 - “Plot Dymaxion Maps in Perl”) to the extreme (#62 - “Build a Car Computer”). A few I found very interesting - #14 “Make Free Maps of the United States Online” describes the US Census Bureau’s TIGER Map Server in some detail. I’ve used TIGER quite a bit, but I learned a new trick from this hack. The web address needed to see one of my experiments is too long for this article, but you can find a link to it at home.neo.rr.com/catbar/ near the top, under “What’s new?” It will load a very big image file, so it might be slow to load on dial up connections. Note the very tiny green dot in Summit County northeast of Wolf Creek - that’s Castle Rock’s location.

You can find the catalog page for Mapping Hacks at www.oreilly.com/catalog/mappinghks/. The page includes some sample hacks from the book, its table of contents and index.

If the car computer hack I mentioned above sounded interesting to you, you might want to watch for O’Reilly’s Car PC Hacks book due to be released soon. Its catalog page is at www.oreilly.com/catalog/carpchks/. It’s a bit earlier in development, so while it has some sample hacks, there is no table of contents or index yet.

I think I’ve got enough info for another article along these lines in the near future. Google just released “Google Earth,” for instance. I haven’t even had time to try it out. It’s supposed to be an awesome way to access geographic information.

Whatever you do, keep your eyes on the road!