On a different note: I can't believe the game is still invite only. Do people still play it? I tried to get into it, but quickly grew tired of it because everyone around me was much better than me and I couldn't sustain the interest needed to learn the ins and outs of getting good at it.
Also, Ingress is "invitation only" in the sense that they will email you an invitation code if you register on their website. <:)
edit downvote without a comment is a crime.
The parent is talking about mapping out WiFi and Cell data through a city. Mapping out it's radio spectrum spatially. Not a traditional human usable map such as a street map, road conditions, or whatever else you may be thinking.