A Vector Airborne Magnetometer measures the three components of the earth's magnetic field, but orients them so as to null out two of them, thus putting the third component in the direction of the magnetic field. This type of instrument served for 25 years as the heart of Project MAGNET, an airborne magnetic survey of ocean areas that began operation in April 1953 under the command of the Naval Hydrographic Office. Project MAGNET continues to this day, though with other sorts of detectors. This example is marked "U.S. NAVY HYDROGRAPHIC OFFICE VAM-2A3." The Naval Oceanographic Office transferred it to the Smithsonian in 1979.
Eric Schonstedt and Henry Irons developed the design while working at the Naval Ordnance Laboratory. It is a refinement of the Magnetic Airborne Detector that the Naval Ordnance Laboratory and Bell Telephone Laboratories developed during World War II, in order to locate submerged submarines.
Ref: E. O. Schonstedt and H. R. Irons, "Airborne Magnetometer for Measuring the Earth's Magnetic Vector,"Science 110 (1949): 377-378; E. O. Schonstedt and H. R. Irons, "Airborne Magnetometer for Determining All Magnetic Components," Transactions of the American Geophysical Union 34 (1953): 363-378; E. O. Schonstedt and H. R. Irons, "NOL Vector Airborne Magnetometer Type 2A," Transactions of the American Geophysical Union 36 (1955): 25-41; Magnetic Airborne Detector Programs. Summary Technical Report. Division 6, National Research and Development Committee, vol. 6 (1946); William Anspacher, et. al., The Legacy of the White Oak Laboratory (Dahlgren, Va., 2000), chapter 10.
- Object Name
- airborne magnetometer
- Physical Description
- metal (overall material)
- ID Number
- accession number
- Science & Scientific Instruments
- Data Source
- National Museum of American History, Kenneth E. Behring Center