ABSTRACT
This chapter provides a brief overview of the tools commonly used for magnetic measurements. The chapter considers the estimation of magnetic target depth, evaluation of spatial sampling criteria, and the merits of magnetic gradient measurements. It introduces magnetic measurements and these are interpreted in conjunction with the previously considered gravity measurements. For the application of magnetic measurements in near-surface geophysics, any magnetic fields that are not associated with near-surface magnetic sources can be considered external. Magnetometry is only capable of detecting buried magnets and while this might appear to be quite limiting, it does have many uses. Many man-made objects are magnets and, although these can be quite weak, they frequently can be detected with sensitive tools of magnetometry. The actual field in the vicinity of the buried magnet will be a superposition of the magnet's field and the Earth's field.
