The birth of electronic warfare

The German electronic air defense system was designed to detect the allied bomber raids, target and aim the German radar-guided weapons, and destroy the American and British bombers. The German air defense system had 100’s of early warning radars, and thousands of radar controlled anti-aircraft guns, and Ground Controlled Intercept radars to guide the fighters into the bombers.

By 1942 the Allied Air Command recognized they needed to reduce allied losses to fighters and flak. We needed a way to shut down the German Air Defense system. (Bear with me as this history takes you from the skies of Europe to Fred Terman.)

To shut it down we first needed to understand the German “Radar Order of Battle.” What radars did the Germans have and what were their technical characteristics? How effective they were? What weapons were they associated with? We needed to find out all this stuff and then we needed to figure out how to confuse it and make it ineffective.

The first job of the secret lab was to find and understand the German air defense system. So we invented the U.S. Signals Intelligence industry in about 12 months (with help from their British counterparts at the Telecommunications Research Establishment.) These mission of the planes called Ferrets, manned by crews called Crows, was to find and understand the German electronic air defense system.  We stripped out B-24 bombers, took out all the bomb racks, took out all the bombs and even took out all the guns.  And we filled it with racks of receivers and displays, wire and strip recorders and communications intercept equipment that could search the electromagnetic spectrum from 50 megahertz to 3 gigahertz, and this is 1943.

We flew these unarmed planes in and out of Germany alongside our bombers and basically built up the “radar order of battle.” We now understood where the German radars were, their technical details and what weapons they controlled.

(from an interesting article on the Secret History of Silicon Valley)