Basically, the magnetic survey techniques aimed at the detection and study of bodies and underground structures from the changes that the presence of these occurs in the Earth's magnetic field, because of differences in magnetic susceptibility and remanence different types of rocks.
A method that uses a natural Newtonian field, so you do not have to create pre and observations are to determine the value of the magnetic field in a series of points (stations) that cover a greater or lesser density, the study area .

APLICATIONS:
The applications of this technique are varied:

• Search and exploration of deposits of magnetic minerals or other associated with them,
• Tectonic studies and geological mapping,
• Study of archaeological sites (both terrestrial and submarine)
• Detection and localization of metal elements and man-made structures in the know,
• Etc.