This post was updated at 4:45 p.m. Thursday afternoon to reflect comment from the U.S. Army.

Military surveillance aircraft slated to be set aloft over suburban Baltimore this year were originally designed to carry video cameras capable of distinguishing between humans and wheeled vehicles from a distance of at least five kilometers, according to documents the Army has newly released to a privacy group.

But the documents, dated from 2009, contain such heavy redactions that it is unclear how precise the resolution was supposed to be for the video systems on the blimp-like aircraft, nor is it clear how often video capabilities have been deployed on them in other locations. The Army's North American Aerospace Defense Command (NORAD), which will oversee the surveillance system's three-year exercise in Maryland, said Thursday that it will not carry any video cameras during that time.

Uncertainty over the capabilities of the Army aircraft has caused concern among privacy advocates. The Electronic Privacy Information Center, based in Washington, said that the blimp-like aircraft could potentially be outfitted with powerful cameras and even with facial recognition systems capable of identifying individual people.

“There is a lot of potential for privacy abuse if a surveillance device can identify a human at five kilometers away,” said Julia Horwitz, the consumer protection counsel for the privacy group, which is fighting a legal battle for information about the surveillance aircraft. Five kilometers is about 3.1 miles.

The Army last year announced that it was bringing its JLENS system, short for Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System, to be tethered on land owned by the Aberdeen Proving Ground. The exercise was scheduled to start in October, but is more likely now to begin in December, said Maj. Beth R. Smith, a spokeswoman for NORAD.

Army officials have previously said that the surveillance system is intended to spot missiles and other threats to national security, not monitor the activities of people living or traveling below along the busy I-95 corridor.

The JLENS system – which includes a pair of white, 243-foot-long balloons tethered to the ground -- can stay in the air continuously for up to 30 days and is designed to spot missiles from a distance of 340 miles. Its radar systems also can detect what security experts call “swarming boats,” the kind of small, agile watercraft that, when loaded with explosives, can threaten ships.

Yet the JLENS aircraft have raised privacy concerns, in part because Raytheon, which developed the program for the Army, has tested the surveillance system’s ability to use powerful, high-altitude cameras capable of seeing people and vehicles from many miles away. Those tests took place at a military facility in Utah.

The Army and Raytheon had previously declined requests from The Washington Post to reveal the video, infrared and other capabilities of JLENS. For a story in January, the Army told the Post that it has “no current plans” to mount the surveillance cameras tested by Raytheon on the JLENS deployment at Aberdeen Proving Ground, but the Army also declined to rule out using such systems or possibly sharing the resulting footage and other information with federal, state or local law enforcement officials.

Calls to the public information officer at Aberdeen Proving Ground were not returned Wednesday afternoon, when the Electronic Privacy Information Center first released information about the 2009 documents. But Thursday afternoon, after an initial version of this article was published, Smith said that plans for the JLENS system had changed since the publication of the 2009 documents furnished to the privacy group.

She said that "absolutely, 100 percent" that JLENS will not have video cameras during its time at Aberdeen Proving Ground. She said the plans for the system have grown firmer since the Army's comments in January. "There was a lot of ambiguity back then. Now the thing is on its way."

Smith also said that initial plans for the JLENS, as described in the 2009 documents, were changed because of concerns that video and infrared surveillance systems were deemed too heavy and unnecessary.

She criticized the Electronic Privacy Information Center, a fixture of the privacy community founded in 1994 by Georgetown University law professor Marc Rotenberg. "I don't really consider them the most reputable source of information," Smith said. "They do sensationalize things quite a bit."

The Electronic Privacy Information Center filed a Freedom of Information Act request in November for information revealing the capabilities of JLENS and followed with a lawsuit in May, after the Army failed to produce any documents. A federal district court judge in Washington on Aug. 20 ordered the Army to release documents. The privacy group has received a first batch, from 2009. The Army must produce others before Oct. 10 under the ruling, and a legal fight likely will continue over the extent of the Army’s redactions.

Rotenberg, president and executive director of the Electronic Privacy Information Center, said the group had merely acquired and publicized documents produced by the Army itself. "It may be the case that the Department of the Army is now backing off its original plan based on the public disclosure."

Horwitz said that the first batch of documents included extensive information on the weapons systems that the JLENS were supposed to have the ability to carry, including Hellfire missiles, but paragraphs related to surveillance capabilities were the most heavily redacted.

Smith said, however, the JLENS as ultimately built was not capable of carrying Hellfire missiles.

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