An Information Security Community
I am not sure if this is worth a blog post but it's definitely too long for a tweet.
Today I was totally blown away by the precision of Apple's location service - on the iPod Touch!
It is well known for a long time that all iOS devices use Apple's location database which is comprised of cell-tower locations as well as the locations of Wifi hotspots and access points. Of course there is also a knowledge base article on that topic on Apple's website.
Whenever an iOS device with active GPS, Wifi and/or GSM/3G sees a cell-tower and/or Wifi hotspot/access point, it stores the current GPS coordinates along with the signal strength and a unique ID of the cell-tower or AP (SSID?, cell-tower-id?).
This is why you have a consolidated.db on your iPhone which came as a surprise for many people when the "news" hit the public.
So it is this data that enables me as an iPod Touch user to have my position localized even though I don't have a GPS built into my device.
And the precision of this feature is something that really blows me away.
I have tested it in various locations. The diameter of the circle around the pin in the Maps or Google Earth Apps indicates how precisely the device can localize you. The larger the diameter, the less precise the location can be pinpointed.
But to my surprise the pin in the center is always spot on - at least where I live and work and enjoy my spare time.
My apartment is about 56 square meters and the point indicates with almost perfect precision if I currently am at the east window or at the western wall inside my apartment.
I don't know if I like that or not but it is quite impressive. I am now wondering if Apple really can achieve this precision by only measuring field strength of the Wifi APs around me. I can hardly believe that.
Can it possibly be, that Apple is using an RF-chip that can also receive and measure GSM - at least rudimentarily?
Of course this is just wild speculation.
At least since this is working so great - can I haz a GPS location tracker app for my iPod Touch? :)