Overview

The magnetometer probe for unexploded ordnance (UXO) detection takes real time readings of the amplitude of the Earth’s magnetic field. Buried ferrous items result in localised distortions of the magnetic field. These local disturbances are manifested as anomalies in the data that are invaluable for locating buried metal objects such as tanks, drums, pipes or bombs.

When no ferrous items are detected, the magnetometer gives a strait line. If unexploded ordnance (or other ferrous items) is detected, the strait line alters sharply.

Total Magnetic Flux

The Total Magnetic Flux in Magnetic_Flux_Total on CPT_DATA_ENVIRONMENTAL table is calculated from

$\begin{array}{l}\displaystyle B = \sqrt{B_x^2 + B_y^2 + B_z^2}\end{array}$

$\begin{array}{l}B_x, B_y, B_z\end{array}$ are the magnetic fluxes in $\begin{array}{l}x, y, z\end{array}$ directions, respectively. The magnetic flux unit is in nT (nanotesla).

Magnetic Flux Gradient

The Magnetic Flux Gradient in Magnetic_Flux_Gradient on CPT_DATA_ENVIRONMENTAL table is calculated from

$\begin{array}{l}\displaystyle \nabla B = \frac {\Delta B}{\Delta z}\end{array}$

$\begin{array}{l}\Delta B, \Delta z\end{array}$ are calculated from two consecutive depth data.

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