Airborne Geophysical Methods

Magnetic airborne survey – geophysical flight

“…Thus, each device used in a survey may require a specific calibration method. Because the magnetometer is a piece of magnetic equipment, any ferromagnetic object in the aircraft, including the engine, can directly interfere with measurements (Hood and Ward, 1969). However, the sensor layout of the aircraft should take this into consideration, as well as the materials used to build the craft, which should be nonmagnetic.…”

“…At altitudes of 3000 ft (914 m) or 4000 ft (1220 m), the incoming soil variations are typically low so that only the heading and maneuvers affect the test. The variations are stored in the system and used for automatic compensation during future data acquisition projects (Hood and Ward, 1969).…”

“…The pilot uses the radar altimeter to maintain a constant height of 91 m above the ground, reaching 150 m if towing a bird (Hood and Ward, 1969). On terrain with accentuated topographical variations, this process makes it difficult to maintain the predetermined altitude.…”

“…These peaks may be caused by railways, power lines, magnetic storms, large metallic masses, ships, buildings, and hangars. In addition, anomalies can be caused by equipment aboard the aircraft that contains chemical substances, which may be detectable by the instrument (Hood and Ward, 1969).…”

“…Discovered by Faraday, Sect. XIX, the method was initially employed by the USSR (currently Russia) in 1936 (Hood and Ward, 1969) and adapted later with better modifications by the United States in 1940 (Hood and Ward, 1969). Both countries had vested interests in military and technology, particularly for submarine applications.…”