IT Professionals

Maps On The iPod Touch

Posted by on Feb 26, 2008 | 13 Comments

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!

  • Buzzby

    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.

  • http://www.justcallmatt.net/ Matt Wilkinson

    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!

  • Andrew Peterson

    But even with the database of Wifi Hotspots and their geographical location. How does the iPod Touch communicate with the Skyhook servers when you are not connected to any wifi? This features seems to still work with auto-connect disabled as well as when you are only surrounded by Encrypted networks.

  • Bj

    Skyhook knows nothing about my home wifi and gets pretty close to accurate it’s about 4 miles from my actual location it has to be something with my ip address nothing else makes sense. I’m sure in this rural area skyhook has no information about my particular location. So some one needs to explain this to me it’s driving me crazy.

  • Jacob

    There actually companies that pay people for using laptops and phones with wifi & gps to gather location data for them. I did it for short time with my gps phone. I went all over to get access points and cellular towers data.

  • Rolando

    According to Google Maps’ “current location” feature, my iPod Touch has my location down to about 50 feet away. I’m in a suburban area, and the only WiFi access point I see on the phone is the one in my house. I’m mystified. Nambu, a Twitter client, seems to think I’m in Russia (or else all of my neighbors are tweeting in Russian).

  • Malcolm

    I can actually add even MORE confusion to this story. I have a program on my Cellphone (an HTC Diamond) called Windows WIFi Router. It actually turns my cell phone into a Wireless Access Point, by enabling the cellphone WiFi, and passing it along to Sprint’s EVDO network.

    So the other day I turned on the WAP on my phone, and connected to it with my iPod touch, and it found my location WHILE I WAS DRIVING AROUND TOWN! The locaiton changed as my location changed while driving! My cell-phone based WAP is certainly unknown by any kind of ‘survey team’. I am completealy baffled! HELP!

  • Alex

    Mine doesnt work at all. It thinks i’m in oslo

  • Emilio

    Here in Mexico google maps works fine but my location don’t work. Maybe later.

  • Somedude

    Google GeoIP. That’s how it works. Really been two years and nobody thought of this?

  • Tom

    How can work on WiFi. My iPod can find my location without even being connected to WiFi

  • Jeff

    I’m baffled, as well. I was driving down a suburban neighborhood full of encrypted home networks, and it still found my current location with an almost 20 feet accuracy. Do you think it’s possible that part of the Skyhook database is stored on the ipod touch? Perhaps only the locations of wifi hotspots within a radius of 10 miles from you home?

    At Somedude, the location from your ip address wouldn’t work, because it would detect only the location of your isp. When tracking with GeoIp, it thought I was around ten miles away than where I actually was.

  • Omar

    i have stupid question ipod touch don’t have built in gps reciver ????
    so i can’t use it on high way ????