Survey sample
Airman Chase Weltmer and Airman Jalen Jones, engineering assistants assigned to the Air Force Reserve 931st Civil Engineer Squadron, demonstrate the operation of a "Total Optical Station" at McConnell Air Force Base, Kan., April 23, 2013. The Total Optical Station is used by civil engineers to ensure correct elevations and angles for structures. (U.S. Air Force photo by Capt. Zach Anderson)