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NEWS | Oct. 1, 2015

Cold War-era collection ‘goniometer’ unveiled

A “goniometer” sounds like something from a science fiction movie. For the hundreds of intelligence analysts who relied on its life-saving results, it was a very real and tremendous advance in technology for its time.


Its time is passing, but will never be forgotten, thanks to the latest historical display unveiled Thursday at 25th Air Force Headquarters here.


Maj. Gen. Bradford Shwedo, 25th Air Force commander, pulled down the black covering before a large group crowded into an entry hall, unveiling the largest and heaviest display ever created for the 25th headquarters.


The goniometer was a part of the high frequency circular disposed antenna array, or AN/FLR-9, affectionately known as an “elephant cage” because each antenna array covered 36 acres. Each goniometer weighed 300 pounds, stood about 5-feet tall, and measured 31 inches in diameter at its widest point.


As he revealed the goniometer display, Shwedo said the timing couldn’t have been better.


“I’m really excited to be a part of this because this kicks off our activities for our alumni week ... and we’ll have the ability to talk to a lot of people who ran this system,” Shwedo said as he mentioned the annual anniversary events through Sept. 26, honoring the 67-year legacy of 25th Air Force.


He congratulated and thanked the 25th AF History Office for its hard work to acquire the goniometer and create the elaborate display detailing its significance.


Shwedo told the crowd that one of the 25th’s predecessor organizations, U.S. Air Force Security Service or USAFSS, used the “elephant cage” arrays to collect signals during the Cold War, and the arrays remained operational for more than half a century. Only one remains operational, at Elemendorf Air Force Base, Alaska.


According to Gabriel Marshall, one of the historians at 25th Air Force, the goniometer was “a radio receiver and antenna used as a system for determining the angular direction of incoming radio signals.” They were housed in small buildings at the center of each elephant cage, and massive, heavy-gauge cabling for each of the three frequency spectrums captured by the array ran through waterproof or water resistant tunnels from the array to the operations building, sometimes located more than a mile away.


The six elephant cage arrays were located at Royal Air Force Chicksands, England; San Vito Air Station, Italy; Karamursel, Turkey; Clark Air Base, the Philippines; Misawa Air Base, Japan, and at Elmendorf. The arrays enabled a very accurate high frequency direction finding capability as well as a significantly enhanced ability to collect radio communications. They were also used as a navigation aid and provided direction finding assistance to search and rescue.


“The goniometer display was a huge team effort and could not have been done without the help and support of several organizations,” Marshall said. “Marc Putney, from 25th AF Logistics, Installations and Mission Support directorate located the goniometer at the Cryptologic Support Depot. The depot loaded and transported the heavy equipment from their warehouse to storage space on JBSA-Lackland, and the public affairs office designed the display graphics.”


Marshall pulled together the unclassified historical information about the goniometer and the array to include in the display.


“Just as Patton called the M-1 Garand rifle the single greatest battle implement of World War II, the goniometer and AN/FLR-9 emerged as a major intelligence achievement in the Cold War,” Marshall wrote for the display.