It is widely used in locating lost utilities, environmental site characterization and monitoring, agriculture, archaeological and forensic investigation, unexploded ordnance and land mine detection, groundwater, pavement and infrastructure characterization, mining, ice sounding, permafrost, void and tunnel detection, sinkholes, subsidence, karst, and a host of other applications. It may be deployed from the surface by hand or vehicle, in boreholes, between boreholes, from aircraft and from satellites. It has the highest resolution of any geophysical method for imaging the subsurface, with centimeter scale resolution sometimes possible.
Resolution is controlled by wavelength of the propagating electromagnetic wave in the ground.
Depth of investigation varies from less than one meter in mineralogical clay soils like montmorillonite to more than 5,400 meters in polar ice. Depth of investigation increases with decreasing frequency but with decreasing resolution. Detectability of objects in the ground depends upon their size, shape, and orientation relative to the antenna, contrast with the host medium, as well as radiofrequency noise and interferences. Copyright 1998-1999 by Gary R. Olhoeft. All Rights Reserved.