U.S. Army 2nd Lt. Chang Ahn and Maj. David McCulley update perimeter maps. U.S. Army 2nd Lt. Chang Ahn, leader of 2nd Platoon, 5th Battalion, 82nd Field Artillery Regiment, and Maj. David McCulley, battalion operations officer with the 5th Battalion, 82nd Field Artillery Regiment, update perimeter maps to increase base security at Joint Base Balad, Iraq, on Sept. 11, 2008. The operation is a joint patrol designed to introduce Security Forces airmen to the base's outer perimeter prior to the airmen taking responsibility of the area from the Army unit. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 717174-Y-JSZ16-126.jpg Photo Gallery