Took me ten minutes to locate the spot, no special equipment needed. It's a knack.
I did have the advantage of knowing your city, though.
I wouldn't be hard to find, either.
I think a lot of systems nowadays are using both GPS and cell signals. The wifi navigator is still a bit creepy to me, but when I see all the neighborhood systems that show up on my laptop it's easy to see that most locations would have a definite "signature."
My own wifi is not only encrypted, I've set it to "hidden," which means it isn't supposed to show up on other computers out there unless they can type in the name. Don't know if Google has a way around that.