Geoposition & iPod Touch ... How's this possible?

[BeVonk!]

I loaded Google Earth on my iPod Touch and to my surprise discovered that my location is very accurately determined and plotted in Google Earth. I use WiFi to connect to my ADSL line at home ... no GPS and no GSM connection to triangulate position. How is this possible? Anyone out there with a technical explanation? How can Google Earth determine my position without GPS or GSM assistance?

 

[Synaesthesia]

It uses a database of known Wi-fi hotspots to find you. It's never worked for me though!

 

[koffiejunkie]

In the UK they use Sky Hook for this. It's really nifty, until someone moves into your neighbourhood with a wifi AP that's already on SkyHook's database. For several months I kept getting a location that's a few miles north of where I live, until GPS kicks in and overrides it.

 

[BeVonk!]

This is news to me. I see Skyhook is even active (early days) here in Cape Town. Clearly Big Brother knows everything like never before. Would never have thought that my little WiFi setup at home matters to a company in Boston.

 

[BeVonk!]

Well now ... when Google did the whole Streetview survey they also collected WiFi data ... so there's the answer I guess (considering Skyhook's methods).

 

[ScrnScrm]

Apple's Location Services use the Skyhookwireless database. The basic sequence is skyhook - > Cell triangulation - > GPS Receiver. If you have an iPhone, its a good idea to add your local Wifi MAC address to the skyhookwireless database, as it makes the location services far more effective and faster. It also saves battery life. Here is the link where you can submit : http://www.skyhookwireless.com/howitworks/submit_ap.php