In a recent article, The Atlantic takes a close look inside at the Googleplex and how Google builds Google Maps. Looking at the competitive environment between Apple and Google, the article focuses on Google and their strength – data – and how their go about indexing and organizing the vast amount of data at their disposal.
In an interesting read, the article comes at you from an insiders perspective as the author meets up with Googlers within the "secret" complex and explores Maps right from the get go when Google began with the rather crude TIGER database from the Census Bureau as a generic basemap and began cleaning, indexing, and adding value to the data. Google then enters into partnerships with other data providers, lots of them! Agencies like the USGS and many other government and commercial data providers complement Google’s database with additional layers of information. The article progresses to look at Google StreetView and how the amazing, feature rich imagery gathered by the roaming vehicles (over 5 million miles driven to date) is used for ground truthing – many people don’t actually realize this.
For a massive, detailed read and inside look at the Google Map Process I highly suggest you enjoy this article – See here on the Atlantic