The combination of search software and a growing global database of remote sensing products is making it increasingly easy for Internet users worldwide to find highly accurate images of just about any place on Earth including some that governments around the world would prefer to keep secret.

Programs like Google Earth, MSN Virtual Earth and their competitors take imagery from a variety of sources, from local government records to high-resolution imagery provided by commercial remote sensing companies, and aggregate it into an easily navigated system accessible by personal computer.

As the popularity of these imagery products increases, however, a number of world leaders are expressing concern that it poses a security risk.

At a speech to Indian police officers Oct. 15, India’s President A.P.J. Abdul Kalam said such programs open up developing countries to potential attacks, and he urged other countries to think hard about the implications of programs like Google Earth and to consider revising their own laws governing imagery distribution.

“When you look deeper into it, you realize that the specific laws in some countries, regarding spatial observations over their territory, and UN recommendations about the display of spatial observations [are] inadequate,” Kalam said, according to a transcript of the speech posted on the president’s Web site.

Kalam joins the chorus of representatives from foreign countries including South Korea and Thailand who are continuing to speak publicly about the inherent security risks they see in the availability of imagery that shows details of sensitive facilities such as nuclear power plants that could be targeted by terrorists.

Merely aggregating available data

In the face of such criticism, U.S. commercial providers, Internet companies and government officials stress that the commercial imagery industry is heavily regulated to avoid the dissemination of material which would be potentially dangerous. For example, according to Google Earth’s Web site, most of the imagery displayed there is one to three years old and not captured in real time.

Google Earth spokeswoman Eileen Rodriguez would not respond to specific questions such as whether any specific locations are obscured by the site, but released a general statement via e-mail saying that Google welcomes dialogue with governments and takes concerns seriously.

“It is important to know that Google Earth is built from information that is already available from a wide range of both commercial and public sources, and is no different in concept from the many other Internet-based imaging and mapping services that have been available for years,” Rodriguez said.

The wide availability of the imagery from other sources was stressed by commercial remote sensing operators as well.

“The principles which govern Earth imaging technologies all favor the availability of commercial remote sensing data,” said Mark Brender, spokesman for the commercial U.S. remote sensing firm Space Imaging Inc. of Thornton, Colo. “Google is merely aggregating data that is already available commercially, not only from U.S. companies, but from other foreign companies and governments overseas.”

National Geospatial-Intelligence Agency spokesman David Burpee said the U.S. Department of Defense has taken into account the fact that locations such as military posts could be visible via satellite imagery.

“This is not necessarily from a military context a new phenomenon,” said Burpee. “Military forces for years have operated under the security assumption that someone from above was watching what they are doing from satellites. It’s always been an operational requirement to take these kind of things into account.”

In addition, Bill Schuster, chief operating officer of the Dulles, Va.-based commercial remote sensing firm Orbimage, Inc., said that it is clear the U.S. government has put a significant amount of thought into the potential consequences of satellite imagery falling into the wrong hands. While Orbimage does not provide imagery to Google Earth, it has an agreement to provide imagery for Microsoft’s Virtual Earth.

Measuring security threats

In order to determine its commercial imagery needs, government officials have done careful studies on what objects are distinguishable at particular levels of resolution, he explained. For example, Schuster said, at one resolution, an individual may be able to differentiate one type of aircraft from another, while another resolution would only be clear enough to distinguish bridges and major landmarks. By awarding Orbimage a commercial license, this demonstrates the government is comfortable with the general public having access to 1-meter imagery, with some stated exceptions, Schuster said.

“The government has thought this through, and the intelligence community has considered what is suitable for the licensing of us,” said Schuster. “The question they’ve had to ask themselves is when this gets into the hands of somebody who is not in the U.S., what threat does that pose to us?”

Chuck Herring, a spokesman for DigitalGlobe of Longmont, Colo., which supplies imagery to Google Earth, said in a statement: “The U.S. commercial satellite imagery industry as a whole is carefully regulated and DigitalGlobe, in particular, strictly adheres to all U.S. Government regulatory licenses and policies associated with the collection and distribution of our satellite imagery.” He declined to comment further, or to discuss the contractual deal it has with Google Earth, except to confirm that the program uses DigitalGlobe imagery.

Licensing restrictions

Commercial remote sensing firms are restricted by both their licensing requirements and the Land Remote Sensing Policy Act of 1992, according to the 2001 RAND Corp. study, “U.S. Commercial Remote Sensing Satellite Industry: An Analysis of Risks.”

Licensing is regulated by the National Oceanic and Atmospheric Administration, which subjects applications to interagency reviews in which the Defense, State and Interior departments, as well as intelligence agencies, all can participate. Congress has imposed additional restrictions, such as the Kyl-Bingaman Amendment to the National Defense Authorization Act of 1997, which states that imagery of Israel with better than 2-meter resolution cannot be sold commercially.

Joanne Gabrynowicz, a remote sensing expert and editor of the Journal of Space Law, pointed out that Google Earth’s high-resolution offerings are largely of major U.S. cities.

“I’ve explored Google Earth just like everyone else, and you can see the policy at work in what’s available,” Gabrynowicz said. “You will get the best imagery in areas where there has been active scientific and political interest in the applications of remote sensing, and you won’t, for example, get good imagery over Israel because there is a restriction on that. If you know the rules of the regulations and the licensing provisions, it’s very visible that Google doesn’t do anything contrary to the regulations.”

Weighing the risks

U.S. industry and government leaders agree that the benefits of the increased availability of imagery that these programs provide outweigh the risks.

“It’s a balancing act, and the judgment from our overseers and from ourselves has been that the advantages to be gained in terms of land use, urban planning and similar kinds of things, as well as preparing for terrorist attacks, outweigh the disadvantage of the potential use by folks who would do you harm,” Burpee said.

And the alternative gets to questionable restrictions on both commercial activity and the flow of information, experts agreed.

“With the philosophy of an open information society, you really have to weigh what you’re afraid of against the closing down of an information society,” said Gabrynowicz. “While we do need to be aware of difficulties and do need to be made aware that the world is a dangerous place, you don’t just shoot down information because of that.”

Schuster believes the recent voices who have spoken out against the programs and availability of imagery likely will not have a dramatic effect on U.S. policy or business practices.

“A far more damaging thing would be if, in fact, there was ever a case where somebody actually used the imagery for some nefarious purpose,” Shuster said.

But he stressed that commercial firms think about these issues and revisit them, saying that Orbimage sometimes even goes beyond policy restrictions when deciding how to handle sensitive data.

“Ultimately, all you can do is work to make sure people operate in a responsible fashion,” Schuster said. “It’s not obvious to me that with all the new things which come out that can affect a society, regulation is the answer to everything.”