Magnetic MASINT Geophysical MASINT

1 magnetic masint

1.1 indicating loops detecting submarines
1.2 mad
1.3 vehicle detectors
1.4 magnetic detonators , countermeasures
1.5 detecting landmines

magnetic masint

a magnetometer scientific instrument used measure strength and/or direction of magnetic field in vicinity of instrument. measurements make can compared signatures of vehicles on land, submarines underwater, , atmospheric radio propagation conditions. come in 2 basic types:

scalar magnetometers measure total strength of magnetic field subjected, and
vector magnetometers have capability measure component of magnetic field in particular direction.

earth s magnetism varies place place , differences in earth s magnetic field (the magnetosphere) can caused 2 things:

the differing nature of rocks
the interaction between charged particles sun , magnetosphere

metal detectors use electromagnetic induction detect metal. can determine changes in existing magnetic fields caused metallic objects.

indicating loops detecting submarines

one of first means detecting submerged submarines, first installed royal navy in 1914, effect of passage on anti-submarine indicator loop on bottom of body of water. metal object passing on it, such submarine, will, if degaussed, have enough magnetic properties induce current in loop s cable. . in case, motion of metal submarine across indicating coil acts oscillator, producing electric current.

mad

a magnetic anomaly detector (mad) instrument used detect minute variations in earth s magnetic field. term refers magnetometers used either military forces detect submarines (a mass of ferromagnetic material creates detectable disturbance in magnetic field)magnetic anomaly detectors first employed detect submarines during world war ii. mad gear used both japanese , u.s. anti-submarine forces, either towed ship or mounted in aircraft detect shallow submerged enemy submarines. after war, u.s. navy continued develop mad gear parallel development sonar detection technologies.

to reduce interference electrical equipment or metal in fuselage of aircraft, mad sensor placed @ end of boom or towed aerodynamic device. so, submarine must near aircraft s position , close sea surface detection of change or anomaly. detection range related distance between sensor , submarine. size of submarine , hull composition determine detection range. mad devices mounted on aircraft

mad rear boom on p-3c



the sh-60b seahawk helicopter carries orange, towed mad array known ‘mad bird’, seen on aft fuselage.

or helicopters.

there misunderstanding of mechanism of detection of submarines in water using mad boom system. magnetic moment displacement ostensibly main disturbance, yet submarines detectable when oriented parallel earth s magnetic field, despite construction non-ferromagnetic hulls.

for example, soviet-russian alfa class submarine, constructed out of titanium. light, strong material, unique nuclear power system, allowed submarine break speed , depth records operational boats. thought nonferrous titanium defeat magnetic asw sensors, not case. give dramatic submerged performance , protection detection mad sensors, still detectable.

since titanium structures detectable, mad sensors not directly detect deviations in earth s magnetic field. instead, may described long-range electric , electromagnetic field detector arrays of great sensitivity.

an electric field set in conductors experiencing variation in physical environmental conditions, providing contiguous , possess sufficient mass. particularly in submarine hulls, there measurable temperature difference between bottom , top of hull producing related salinity difference, salinity affected temperature of water. difference in salinity creates electric potential across hull. electric current flows through hull, between laminae of sea-water separated depth , temperature. resulting dynamic electric field produces electromagnetic field of own, , titanium hull detectable on mad scope, surface ship same reason.

vehicle detectors

the remotely emplaced battlefield surveillance system (rembass) army program detecting presence, speed, , direction of ferrous object, such tank. coupled acoustic sensors recognize sound signature of tank, offer high accuracy. collects weather information.

the army s an/gsq-187 improved remote battlefield sensor system (i-rembass) includes both magnetic-only , combined passive infrared/magnetic intrusion detectors. dt-561/gsq hand emplaced mag sensor detects vehicles (tracked or wheeled) , personnel carrying ferrous metal. provides information on base count of objects passing through detection zone , reports direction of travel relative location. monitor uses 2 different (mag , ir) sensors , identification codes determine direction of travel.

magnetic detonators , countermeasures

magnetic sensors, more sophisticated inductive loops, can trigger explosion of mines or torpedoes. in world war ii, tried put magnetic torpedo exploder far beyond limits of technology of time, , had disable it, , work on also-unreliable contact fuzing, make torpedoes more blunt objects banged hulls.

since water incompressible, explosion under keel of vessel far more destructive 1 @ air-water interface. torpedo , mine designers want place explosions in vulnerable spot, , countermeasures designers want hide magnetic signature of vessel. signature relevant here, mines may made selective warships, merchant vessel unlikely hardened against underwater explosions, or submarines.

a basic countermeasure, started in world war ii, degaussing, impossible remove magnetic properties.

detecting landmines

landmines contain enough ferrous metal detectable appropriate magnetic sensors. sophisticated mines, however, may sense metal-detection oscillator, and, under preprogrammed conditions, detonate deter demining personnel.

foerster minex 2fd 4.500 metal detector used french army.

not landmines have enough metal activate magnetic detector. while, unfortunately, greatest number of unmapped minefields in parts of world cannot afford high technology, variety of masint sensors demining. these include ground-mapping radar, thermal , multispectral imaging, , perhaps synthetic aperture radar detect disturbed soil.