Rooftop geocoding introduced to Google Maps; Time for a Virtual Earth rematch?
By William M. Hartnett on May 1, 2008 in featured, geekery
Here’s an incredibly welcome development: Rooftop geocoding for 50 million U.S. addresses was just rolled out in the Google Maps API. Careful readers will recall my colleague Matt’s head-to-head comparison of geocoding accuracy in Google Maps and Virtual Earth, which I wrote about back in January. Briefly, 85 percent of Virtual Earth’s results were closer to the actual centroids of 400 random West Palm Beach residential parcels than the points returned by Google Maps.
Ah, but that was then, when Google was still using address interpolation as its main geocoding method. Maybe I can bug Matt into repeating the test. Until then, perhaps it’s worth noting that Google claims 50 million rooftops to Virtual Earth’s 44 million. Interesting. Your move, Microsoft.
Hit the jump to see an example of Google’s new and improved geocoder (with the same 3-year-old imagery, sadly).
As a reminder, here’s where Google dropped its pin back in January for the house highlighted in red:

And here’s how Google did today. The pin is directly over the driveway of the correct house:

And the Virtual Earth result, also spot-on:




















Richard | Aug 7, 2008 | Reply
Virtual Earth had rooftop geocoding for 60 million location sin the US last October. They now have over 90 million.
William M. Hartnett | Aug 7, 2008 | Reply
@Richard: Was just quoting, and linking to, the figure listed on one of the official Virtual Earth blogs in April 2008.
Alex | Nov 3, 2008 | Reply
Yes, but where are these rooftops geocodes coming from? It’s not based on a process like address geocoding, it’s based on a database of locations that happen to match the address being searched on. But who provides the data? I do not think it is that Google and MS are actually originated the data…
William M. Hartnett | Nov 3, 2008 | Reply
@Alex: Like most of the imagery and street data in both companies’ mapping products, the geocoding technology appears to usually come from outside providers.
Brian Sobel | Nov 28, 2008 | Reply
Any idea of how MSVE compares with international addresses?
William M. Hartnett | Nov 28, 2008 | Reply
@Brian: No, I don’t know much about geocoding accuracy outside of the United States.