The Army has ruled out installing high-powered video cameras on a pair of blimp-like surveillance aircraft that will start hovering soon above suburban Baltimore for a three-year exercise, a military official said.

The announcement comes after news reports and pressure from privacy groups, which raised concerns about those living and traveling under the gaze of the aircraft. The Electronic Privacy Information Center sued to force the release of documents related to the aircraft after the Army failed to provide a timely reply to a Freedom of Information Act request.

The Army and Raytheon — the developer of the JLENS, short for Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System — declined to tell The Washington Post in January what video and infrared equipment the surveillance system would carry.

The Army would not rule out using a particularly powerful suite of Raytheon surveillance gear that the company tested on a JLENS in Utah a year earlier. It was capable of spotting “trucks, trains and cars from dozens of miles away,” according to a Raytheon news release in 2013. The Army also declined in January to rule out sharing video or other information feeds produced by JLENS with federal, state or local law enforcement officials.

Army documents from 2009 — released to the Electronic Privacy Information Center last month on the order of a federal district court judge — showed that the JLENS was once designed to carry video and infrared equipment capable of spotting objects from at least five kilometers (3.1 miles) away and distinguishing between vehicles and humans.

This week, however, after The Post reported that documents released to the Electronic Privacy Information Center showed a requirement for video and infrared capacity, the Army said that the requirement had subsequently been dropped. Maj. Beth R. Smith, a spokeswoman for the North American Aerospace Defense Command (NORAD), said that the JLENS due for deployment on land owned by Aberdeen Proving Ground will “absolutely, 100 percent” not include video capacity.

Smith said that the 2009 documents released to the Electronic Privacy Information Center were outdated and that documents from later years — which also will be released to the privacy group over the next several weeks — will show the changes in requirements for the JLENS.

She also said that the Army’s plans for the exercise in suburban Baltimore had grown more concrete since January, when other officials expressed uncertainty about plans for its surveillance capabilities.

“There was a lot of ambiguity back then,” Smith said. “Now the thing is on its way.”

Construction has begun for the JLENS base stations, which will be near Interstate 95, about 45 miles northeast of Washington.

Marc Rotenberg, president and executive director of the Electronic Privacy Information Center, said, “It may be the case that the Department of the Army is now backing off its original plan based on the public disclosure.”

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 340 miles. Its radar systems also can detect objects on the ground or water, including what security experts call “swarming boats,” the kind of small, agile watercraft that, when loaded with explosives, can threaten ships.

Smith said the JLENS is expected to be set aloft in December, two months later than planned. A Government Accountability Office report in March 2013 put the development costs for JLENS at $2.7 billion. There are two working JLENS systems, called orbits.

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