Run, don’t walk, to one of the best articles yet written about how Google Earth does its magic:
It is written by Avi Bar-Ze’ev, who was one of the developers on early versions of Google Earth, when it was still Keyhole Viewer. He starts off his series by looking at how Google Earth renders a 3D virtual globe, and he does this by explaining the various concepts underlying Google’s patent applications, some of which have been made public only recently.
(BTW, Avi also got a long response from NY State Assemblyman Michael Gianaris regarding his desire to censor imagery of infrastructure in Google Earth.
I think he still doesn’t get it — his argument is just wish-thinking: Google isn’t obligated to buy from (potentially censored) US imagery providers; the company could just as well buy it from foreign providers. And if Google and other US companies were compelled to censor their imagery or prohibited from using foreign providers, then there are plenty of map and globe competitors abroad that will and can provide the imagery.
Removing such imagery from Google Earth means that only those who are the most motivated get access (e.g. terrorists, who can use a number of alternate sources and who often have rogue government support) while concerned citizen loses a resource. Want to check if the local power plant is obeying zoning laws? Not if Google Earth has blurred it. Google Earth and other mapping services like it provide checks and balances for the public on their government. If that is taken away, then the terrorists have already won, to overuse that phrase.)