StreetView Cars Collecting 3D Data on Buildings

San Francisco in Google Earth 4.3

CNET has a story "revealing" that Google has been collecting 3D data in addition to the imagery shown in the StreetView map views. This may come as a surprise to some out there, but there was a May 2007 story from the San Jose Mercury News that Google would be using technology from Stanford University to collect 3D data from the car systems This does pose the question whether the new 3D buildings added with Google Earth 4.3 for several cities used the new system. But, since Baltimore for example got the new 3D buildings, and there aren't StreetView photos for that city, I'm thinking perhaps they have yet another method of generating 3D buildings. Also, I think it would be hard to generate 3D buildings of skyscrapers using this technology. My guess is it would be better for smaller buildings - and maybe trees? - than for cities. My theory: Google will use a combination of technologies for 3D model generation - and they'll be trade secrets.