Staff Sgt. Jeremiah Johnson, a Combat Shield team member assigned to the 16th Electronic Warfare Squadron, Eglin Air Force Base, Florida, supports a USM-642 “Raven” signal generator cable during Combat Shield, Oct. 20, 2015, at Seymour Johnson Air Force Base, North Carolina. Combat Shield originated in the early 1990s with the purpose of assessing the electronic warfare readiness of the entire fighter fleet. (U.S. Air Force photo/Senior Airman Aaron J. Jenne)