It doesn’t seem likely that Google is using cell phone towers, but I could be wrong. I notice that Google Maps on my iPad picks me up better when I am in a larger city as opposed to the countryside. Although, at times, it does find my location on some country roads.
My iPad 3 wifi signal is not very strong, but it must be strong enough to pick up some kind of signal to tell the map where my location is. I think that Google is using the signals emitted from homes. But, my iPad 3 normally can’t pick up the internet very far from any kind of home.
The location signals must work on a very weak field. It’s kind of cool to quickly find out where I am to know where I need to go. As a homeless loser, this helps prevent me from accidentally wandering into any rich neighbors by mistake.
I used to borrow other peoples wifi signals to surf the internet as far back as 2008. But now, with security as high as it is, everyone has a password. But they may not be able to stop the location signals. This is assuming that Google is using home wifi networks to detect my location. I’m not sure.