It's all about precision
Tech Sgt. Jennifer Greer uses surveying equipment to calculate the height of a water tower during a field exercise May 26, 2011, at Tyndall Air Force Base, Fla. Sergeant Greer, a reservist, is an engineering craftsman assigned to the 446th Civil Engineer Squadron at Joint Base Lewis-McChord, Wash. (U.S. Air Force photo by Staff Sgt. Grant Saylor)