Maps On The iPod Touch
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Although I didn’t agree with Apple charging for its major software update to the iPod touch — I went ahead and did it anyway. It included features and enhancements that I thought would be handy to have. The upgrade itself was super easy — iTunes pretty much handled it all.
One of the nice new features included Google Maps. But there was one part of how Google Maps functioned on the iPod touch that just mystified me. And I am calling upon all Gnomies for somebody to explain how it works.
Using local Wi-Fi access points, it is able to roughly approximate your location. Whoa. How is that possible? I know the basics of how GPS works (my BlackBerry 8310 has on-board GPS), I also know that the newer iPhone software allows for “faux-GPS” using cell phone tower triangulation. But how does the iPod touch determine approximate location using Wi-Fi access points? I’m guessing something involving IP addresses and ISPs. But how the heck would that even work (and work so quickly)? I know that law enforcement can track somebody’s computer by back-tracing their workstation’s (or router’s) public IP address through the ISP. But I imagine that being a far from instant process.
Somebody enlighten me, please!
2 Comments
Buzzby
February 27th, 2008
at 6:35am
The system is from Skyhook Wireless http://www.skyhookwireless.com/howitworks/
To Quote:
“The WPS (WiFi Positioning System) location client identifies all of these existing Wi-Fi signals and calculates your current location using groundbreaking positioning algorithms developed by Skyhook Wireless. WPS requires knowledge of the specific geographic location of individual access points in order to deliver highly accurate results. This information is obtained by deploying hundreds of data specialists who scan and locate access points using proprietary scanning vehicles designed to build and maintain the reference database. The system also takes into account movement by individual access points and helps to automatically heal the network by updating and improving the reference data in real-time.”
So this is something that will work best in urban areas with a high density of access points and poorly/not at all in areas where there are few WiFi access points or areas that haven’t been surveyed.
Matt Wilkinson
February 28th, 2008
at 7:53am
Buzzby — wow, that’s exactly what I was looking for. So Skyhook sent out a fleet of surveyors, creating a database of access points. Kind of cool, yet kind of scary.
Thanks!