Explainer

Google’s Blind Spots

Can governments get Google Earth to obscure images of sensitive locations?

The 10 gunmen who terrorized Mumbai last week used Google Earth to plot their attacks, according to statements made by the sole captured terrorist. The attackers targeted public areas whose locations were already available on printed maps, but can a government ask Google to exclude images of more sensitive areas from Google Earth?

It can try. Google doesn’t automatically exclude photos of locations that might represent a security risk, such as nuclear facilities or the homes of political VIPs. But it has fielded requests to do so in the past—as in 2007, for example, when British troops discovered that insurgents in Basra had been printing out detailed Google Earth images of U.K. military bases. In response, Google replaced its satellite shots of Basra with an earlier set of photos, taken before the war began. A Google spokeswoman told the Explainer that this is the only image alteration the company has made due to a governmental request. (She denied reports that Google had agreed to distort images of certain Indian locations in 2007 but acknowledges that the company did have conversations with government officials.)

Sometimes, what may look like an alteration is actually the result of a lackluster data set. Google Earth—which also provides the “satellite view” images for Google Maps—gets all its imagesfrom third-party sources—primarily commercial satellite image providers like DigitalGlobe and GeoEye, but also local municipalities and governmental agencies. (A copyright line with source information can be seen at the bottom of any Google Earth image. The latest version of Google Earth also offers time stamps when available.) Google says its goal is to have the sharpest, most up-to-date photos possible, but it has to work with what its providers can offer—currently, Google Earth has high-resolution images of just 30 percent of the earth’s land surface. So a blurry image—or a blurry square in a large, composite image—might simply mean that Google doesn’t yet have a clearer shot of the area in question.

Some locations seen on Google Earth, however, do appear to have been altered: See, for example, the Naval Observatory in Washington, D.C., home of the vice president, where everything within the road encircling the Observatory is blurrier than everything surrounding it. Or Soesterberg Air Base and Huis Ten Bosch Palace in the Netherlands, which are represented by choppy pixels. Such instances occur because governments can, in certain cases, exert control over Google’s third-party image providers. Most of the very high-resolution images on Google Earth are actually aerial photos, not satellite photos; that means they’ve been taken from within a nation’s airspace and are therefore subject to that nation’s rules and regulations. For example, when the Geological Survey wanted to fly over Washington, D.C., to take photos in 2005, it had to promise the Secret Service that it would delete or edit anything that might “jeopardize national security.”

Google says that it takes a variety of factors into consideration when it decides which images to use on Google Earth—sometimes it will choose an older, low-res photo rather than a newer, doctored one; in other cases, the usefulness of a high-resolution image outweighs the fact that it has a blurry spot.

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Explainer thanks Stefan Geens of Ogle Earth, Kate Hurowitz of Google, and Frank Taylor of Google Earth Blog.