160918-N-OI810-129 PHILIPPINE SEA (Sept. 18, 2016) The Navy's only forward-deployed aircraft carrier, USS Ronald Reagan (CVN 76), conducts a live-fire exercise of its Phalanx Close-in Weapons System (CIWS) during Exercise Valiant Shield 2016. CIWS combines a 20mm Gatling gun with search and tracking radar to provide surface ships with terminal defense against anti-ship missiles. USS Ronald Reagan is participating in Valiant Shield, a biennial, U.S.-only, field-training exercise with a focus on integration of joint training among U.S. forces. This training enables real-world proficiency in sustaining joint forces through detecting, locating, tracking and engaging units at sea, in the air, on land and in cyberspace in response to a range of mission areas. (U.S. Navy photo by Mass Communication Specialist 3rd Class Nathan Burke/Released)