When single sensor magnetic surveys are not enough

The Science: Collecting more detail in aeromagnetic surveys

Aeromagnetic surveys are commonly flown with a single magnetic sensor, but there are circumstances where additional magnetic sensors can be beneficial. Multiple sensors taking simultaneous measurements in fixed relative positions allows the magnetic gradient to be measured rather than calculated.

The Tool: Gradient Magnetic Surveys

When an aeromagnetic survey is flown with two or more magnetic sensors with a known separation, the magnetic gradient can be directly measured as the difference in magnetic field between the sensors divided by the distance. This has significant advantages in certain situations, especially when the magnetic targets are shallow.

Gradient magnetic surveys can be flown by fixed wing or helicopter. Precision’s helicopters and fixed wing survey aircraft can be equipped with three magnetic sensors in a fully certified triple boom configuration providing a large amount of separation in the x and y axes. Our GoMag, slung, aerodynamically stable, four-sensor magnetometer system provides gradient measurements in the x, y, and z axes for the ultimate in low-noise triaxial resolution and versatility using local helicopters.

Compensation and 3D positioning of individual magnetic sensors reduce aircraft noise and improve sensitivity. By applying intelligent gridding algorithms to 2-axis or 3-axis gradient data, a significant improvement in the spatial positioning of small magnetic bodies can be achieved. Laterally continuous horizons, especially if they are parallel with the flight line direction, will be more apparent.