MNF Equipment Register - Equipment Details

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Marine Magnetics SeaSPY2 Overhauser Magnetometer    - Search for deployments and/or events


This system uses an omnidirectional Overhauser sensor that requires no realignment or recalibration and has no heading error. The instrument has an absolute accuracy of 0.1 nT, sensor sensitivity of 0.01 nT and resolution of 0.001 nT.


The Marine Magnetics SeaSPY2 marine magnetometer measures the earth's total magnetic field and detects variations in the field caused by geological and/or man made (ferrous metal) influences.


Weight 12 kg on land
Deployment requirements: The magnetometer is launched with the aid of the ship's A-frame and can be deployed whilst slowly underway (~1 kn). The instrument is paid out and towed ~300 m behind the vessel (to avoid the ship's influence on the signal) and can be operated at full transit speed. The depth at which magnetometer tows is dependent on vessel speed and/or whether special weights are added to the cable (note: these need to be lead or brass and are not yet a part of the system). One can expect a towing depth of 22 m at 4  kn and 6 m at 12 kn (unweighted). The magnetometer can not be towed at the same time as any other towed system(s), such as: seismic streamer, CPR, Triaxus, towed camera or dredge. This is important to note for the planning of ship's time & activities.

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