Tuesday, April 05, 2005

Google Maps

Google purchased Keyhole last October and dropped the access price to $29.95, but as their blog reports incorporated Keyhole technology into Google Maps and Google Local. Now when you type an address into Google Maps, you can click the 'Satellite' link and see a view of the area. You can zoom, move the view by dragging, and even resize the window just like the normal 'Maps' view.

For example I did a Google Map search for my house, and got

I then clicked on Satellite

and got

As DirectionsMag reports Coverage is limited to about half of the U.S. according to Keyhole's general manage, speaking to the Associated Press. One blogger reports "the satellite images are currently only available for North American addresses but will be introduced for other regions as the year progresses."

The imagery is from DigitalGlobe and EarthSat. That leads to some interesting seams between different resolution images, and those acquired at different times of year. One area I viewed had vibrant sharp (high resolution) green fields on one side with a brown, fuzzy landscape on the other. The best resolution I found allowed the viewing of cars - so it's likely three meter data at best. Keyhole's website notes that it has high resolution imagery for certain areas, for example, down to 3" resolution in Cambridge, Massachusetts. That detail does not seem to be available via Google Maps. Further, what data are available are watermarked "© 2005 Google." While that may frustrate geospatial data users, from a commercial standpoint, Google is making the correct decisions regarding resolution choices and watermarking at this point.

No "flying" is available in this version; that requires the subscription version of Keyhole. Keyhole is noted for its "3D fly overs," which put the company on the map during the early part of the Iraq war. Still, panning and zooming with the images are as fast as with the old "map" option.

Those following the announcement expect that this move will prompt Google Maps competitors to jump into imagery. Recall that MapQuest did have free imagery, from GlobeXplorer for a brief time, but the deal ended in 2004. MapQuest's FAQ regarding imagery simply provides a link to GlobeXplorer. Other mapping portals, including National Geographic's Map Machine and ESRI's MapShop, incorporate GlobeXplorer's technology and imagery.

The other company that should be concerned, some say, is Amazon's A9 search engine which recently began offering photos of the faces of businesses. I see that as a separate set of data; seeing the front of a business is quite different from seeing roofs. Recall that most people are very familiar with looking at businesses' front doors, but are less experienced in aerial imagery interpretation.

Orin Kerr blogged This story about the service focuses on the privacy concerns, which seem relatively modest now but will become quite troubling if and when the resolution of the maps improves.

Notably, Google has blacked out or blurred some areas with national security importance. For example, this picture of the White House has the contour of the buildings blacked out. Interestingly, Congress's image is blurred while the Supreme Court's is clear: see the picture of both here.

Gordon Smith blogged This thing is addictive!

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