USAF Security Service

The United States Air Force Security Service (often abbreviated USAFSS) was essentially the United States Air Force's cryptographic intelligence/Signals Intelligence (SIGINT) branch; its motto was Freedom through Vigilance. It was created in October 1948 and operated until 1979, when the branch was re-designated the Electronic Security Command. It was later re-designated Air Force Intelligence Command, Air Intelligence Agency, the Air Force Intelligence, Surveillance and Reconnaissance Agency, and is currently designated as the Twenty-Fifth Air Force (25 AF).

Composed primarily of airmen selected from the cream of the Air Force's enlisted recruits (the top 1/2 of 1 percent), the USAFSS was a secretive and tight-knit branch of Air Force cold warriors tasked with monitoring, collecting and interpreting military voice and electronic signals of countries of interest (which often were Soviet and their satellite Eastern bloc countries). USAFSS intelligence was often analyzed in the field, and the results transmitted to the National Security Agency for further analysis and distribution to other intelligence recipients.

Individual airmen—stationed at locations scattered across the globe, ranging from Northeast Cape Air Force Station, Alaska to Pacific Islands to The Far East to Mediterranean Countries to The Middle East to Western Europe to North Africa—did a variety of jobs, almost all of them related to listening to and interpreting Eastern Bloc, Communist Chinese, and North Vietnamese military communications. Some airmen were linguists who listened to voice communications. Others—known as morse intercept operators, or "ditty-boppers"—monitored Soviet and other nations' military Morse code broadcasts. Others, such as non-morse intercept operators, were engaged in monitoring other types of radio signals such as single and multi-channel radio printer signals and facsimile transmissions. All communications were reviewed and interpreted by analysts.

...
Wikipedia