Multimedia Gallery
The hand-held GPS receiver was used for tasks such as land surveying and providing accurate time.
Navigation cadets of the 477th Bombardment Group.
Gee receivers like this one were used extensively in the Allied bombing campaigns over Europe during World War II.
Joseph Guenther used a Defense Advanced GPS Receiver (DAGR) to direct artillery fire.
The U.S. Naval Observatory Alternate Master Clock at Schriever Air Force Base.
Used to provide radio time signals to ships and aircraft.
Aviator Ruth Elder and her co-pilot/instructor George Haldeman disappeared over the Atlantic creating a desperate scramble to determine their whereabouts.
She served as an instructor at the U.S. Naval Reserve Air Auxiliary Station at Camp Kearney, California.
This station was one of the first to make radio time signals available.
