Monitoring human rights? Get a satellite.

Satellites can monitor volcanoes, map deforestation, and help sell real estate. But can they document human-rights violations?

Yes, activists say.

Already, high-altitude images of Zimbabwe's destruction of a settlement has increased pressure on the government to curb its abuses. Now, human-rights groups are focusing on Darfur, Chad, and Burma. In eastern Burma, for example, the government is accused of aggressively attacking an ethnic minority.

Burma "is a black hole," says Jeremy Woodrum of the US Campaign for Burma. "Media and aid agencies can go into Darfur in Sudan, but they can't get into eastern Burma; it's totally off limits."

Even in such closed countries, satellites can detect military destruction, the movement of refugees, even their living conditions. They may be able to show the scale of government rebuilding and whether some groups are benefiting more than others.

The idea of using satellites has intrigued activists for several years, notes Ariela Blätter, director of conflict prevention and response for Amnesty International USA. Some organizations have used commercial satellite images on rare occasions, she adds. "But this new, unimpeachable technology has such a huge price tag" that the community has been slow to adopt it.

A foundation grant and technical help from the American Association for the Advancement of Science in Washington could speed its use. The effort has been under way since this past December, when the MacArthur Foundation handed the AAAS a $110,000 check to help human rights groups use commercial satellite images to document abuses.

The first results appeared May 31, when the AAAS and Amnesty International released before-and-after photos of Porta Farm, a settlement the Zimbabwean government destroyed last June.

The 16-year-old settlement had boasted schools, a children's center, and a mosque, according to Amnesty International's Kolawole Olaniyan. It was home to between 6,000 and 10,000 mostly poor Zimbabweans. The new photos showed the entire settlement destroyed and abandoned. United Nations monitors noted that during the demolition several people, including two children, were killed. The government reportedly is trying to build new homes for the more than 700,000 displaced nationwide by last June's operation, but aid workers say the number of new houses is extremely small compared with the large number of displaced Zimbabweans waiting for shelter, land, and jobs.

The satellite images, taken in June 2002 and again this past April, offered key graphic evidence of what had happened. They "epitomize the apex of a man-made disaster, and they can be of a phenomenal impact in redressing such absurdities, now and in the future," noted Zimbabwe human-rights attorney Otto Saki in a statement May 31. He and colleagues with the Zimbabwe Lawyers for Human Rights in Harare say the images could be valuable in a case they are bringing against government officials accused of masterminding and carrying out the operation.

In Burma (also called Myanmar), satellite images could also help clinch the case that human rights groups have been building based on refugee accounts, says Mr. Woodrum. His group hopes to present its images to representatives of several countries that have relations with Burma. "They have no idea" how serious the situation is, he says.

Last week, the satellite effort drew special mention in the government-run Burmese press. It charged that the cofounder of Woodrum's group, Burmese expatriate and former government prisoner Aung Din, is a "terrorist" in his efforts to "fabricate [an] ethnic cleansing issue against [the] Myanmar government."

So far, much of the AAAS's efforts have focused on documenting past abuses, using archived images that a pair of companies are making available for free, says Lars Bromley, with the science organization's office of international initiatives. The ultimate goal is to develop an early-warning capability that allows groups to focus the public eye on relatively small-scale abuses before they become large-scale crises, he adds.

In one case, groups in India have asked him to track the construction of healthcare facilities there, he says. Statistical tests applied to the data, Mr. Bromley says, can indicate the likelihood that government officials are giving preference to certain classes or certain economic or ethnic groups when they site new clinics.

Such efforts aren't cheap, he notes. Setting up the lab to process the images costs around $10,000, putting it out of reach of many human rights groups. [Editor's note: The original version mistakenly attributed the cost to each workstation rather than the overall lab.]

Still, several human-rights activists are enthusiastic about the prospects for adding eyes on orbit to their expanding arsenal of high-tech and low-tech tools.

Amid the newest "targets" for gathering orbital evidence: eastern Chad. Amnesty International released a major report Tuesday on human rights abuses in the conflict there and is collecting satellite photos to bolster its case.