Google maps preliminary locatrion source?

[MikeInPoulsbo]

Google maps displays a preliminary location before the GPS gets a lockon. I understand its based on the tower the phone is using but the location displayed is not actually at the physical location of any tower.
How is this information derived and from where? My phone reception has been extremely spotty due to AT&T tower problems in my area and I'd like to know if I can use the Google maps information to determine what tower I am currently using.

 

[jgreetham]

I don't know for sure but my guess is that it's triangulating from several towers. The initial position is too close to where I actually am, not a single tower location.

 

[MikeInPoulsbo]

I don't know for sure but my guess is that it's triangulating from several towers. The initial position is too close to where I actually am, not a single tower location.

The locations shown are very consistent, down to the tree nearly! I suspect there is a lat/long database somewhere that stores the information.