The US Naval Security Group (NAVSECGRU) was an organization within the US Navy tasked with intelligence gathering. A large part of this was signals intelligence (SIGINT) gathering, cryptology and information assurance. NAVSECGRU was active from 1935 to 2005 when it was folded into the Naval Network Warfare Command (NETWARCOM).
SIGINT is intelligence gathering by interception of signals between people (communications intelligence, aka COMINT) or electronic signals not used for direct communcations (electronic intelligence, aka ELINT). Sensitive information is generally encrypted and this is where the cryptologists would enter into the equation.
Often times, the US would fly planes near sensitive Soviet Bloc countries to arouse suspicion and cause the Soviets to use their radar and communications systems. The ELINT specialists would then soak up as much information as they could, interpret it and send it off to Washington to give us a better understanding of the Soviets' capabilities.
NSGA Winter Harbor operated from 1935 until 2002, when it was excessed by the Department of Defense. NSGA Winter Harbor was actually a replacement for an existing radio site across Frenchman Bay on Otter Cliffs (south of Bar Harbor). The Naval Radio Station at Otter Cliffs was built in 1917 and was the Navy's best transatlantic radio site because it had an unobstructed shot across the ocean and because Mount Desert Island was so isolated that there was no other radio noise. By the 1930's the site's buildings were run down and needed replacement badly.
John D Rockefeller suggested that the site be removed and that the Navy include it with his land donation to Acadia National Park. The Navy agreed, provided that Rockefeller built a replacement site. Rockefeller agreed and had a site constructed across the bay on the tip of the Schoodic Peninsula. This site was commissioned in 1935 and grew into the NSGA Winter Harbor Site.
The mission of sites like NSGA Winter Harbor was to use their Wullenweber Antenna Array in conjunction with ELINT satellites to triangulate the location of foreign warships. Not only did this enable the US Navy to track foreign warships, but it provided ships equipped with cruise missiles with a means of over the horizon targeting.
Life-span of the satellites was approximately 7 - 8 years and, with the last batch being launched in 1995, closing the site in 2001 and turning it over to the public in 2002 made sense.
The site's Wullenweber Antenna Array was probably the feature by which it was most commonly identified. Often called an Elephant Cage because of its ring shape and tall antenna poles, the Wullenweber was a Circularly Disposed Dipole Array (CDDA) that used vertical radiator elements in a ring with vertical reflector elements installed behind them in a smaller diameter ring for high frequency direction finding (HF/DF).
Make sure to check out page 2 for more pictures.
These images were taken in April of 2010 when I was fortunate enough to be invited along on a tour of the site with some members of the US Naval Cryptologic Veterans Association. To Bob, Dave, Larry and Dick: thank you very much for including me in your group for this rare opportunity.
I also want to thank Liz and Joanne for joining us. They happened to be out enjoying nature, ran into us and decided to tag along for the opportunity to learn a little Naval history from some of the men who were stationed here and around the globe.