Radar signal analysis applications require highly specialized test equipment to model and test transmitted or received signals. Secondary surveillance radar (SSR) is a type of radar that is often used for air traffic control (ATC) applications as well as identify friend or foe (IFF) military applications.
For these applications custom RF test racks are assembled for the specialty testing performed on this equipment. Unlike the interrogators and transponders, or the product used in the field, the test racks themselves are not limited by size or military specifications, but by accessibility and modularity.