Electromagnetic methods use the principle of induction to measure the electrical conductivity of the subsurface.
Very Low-Frequency (VLF) systems for ground surveys. The VLF survey technique is a passive electromagnetic method that uti.. more
Frequency Domain EM (FDEM) is a technique in which electric and magnetic (EM) fields are induced into the ground by applyi.. more
Time-Domain EM (TDEM) is a geophysical technique in which electric and magnetic (EM) fields are induced by transient pulse.. more