G-882 Marine Magnetometer

Magnetometer

The G-882 magnetometer emplys an optically pumped Cesium-vapor atomic resonance system that functions as the frequency control element in an oscillator circuit.  the frequency of the magnetometer's electrical oscillator is known as the Larmor frequency, this oscillation varies with the external ambient magnetic field.  We measure those variations and send them to a computer for display and recording.

Where there are materials that have iron in them (cables, pipelines, different types of rock, small artifacts like nails or big items like a steel ship) the earth's magnetic field distorts about the object and the cesium magnetometer sees this distortion as an increase or decrease in the earth's field intensity.  In the northern hemisphere, we will typically see an "anomaly" over a ferrous object which presents dipole structure with a magnetic high to the south of the object and a magnetic low to the north.

The very high sensitivity of the cesium magnetometer allows it to detect small targets at quite large distances.  For localized objects, the magnetometer can sense anomalies of 1 ton (1000kgs) or iron or steel at 100 feet (30m) or more, 250lbs (100kgs) at 50 feet (15m) and 30lbs (15kgs) at 25 feet (10m) or more depending on the background magnetic noise level of the earth