magnetic method

Multichannel magnetic gradiometry uses several closely spaced sensors mounted on a non-magnetic carrier to record magnetic-field gradients simultaneously, enabling rapid, high-resolution mapping of shallow subsurface features. On land the system is commonly mounted on wheeled carts, with sensors separated by about 0.5 m and positioned using GNSS. In shallow water, the same principle is applied using either submerged or floating configurations. Motorized survey modes mount or tow the sensor array using all-terrain vehicles or powered boats, increasing coverage speed while requiring careful control of vibration, survey velocity, positioning accuracy, and sensor height.

Fluxgate gradiometry

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