Ground Penetrating Radar

Ground penetrating radar (GPR) uses radar pulses to image the subsurface. GPR has a variety applications; it’s use in utility locating is to detect traditionally non-locatable subsurface features, including:

  • Non-metallic pipes, including PVC and asbestos cement
  • Concrete storm and sewer systems
  • Utilities where installed tracer wiring has failed
  • Underground storage tanks and drainage tiles
  • Septic system components
  • Non-utility structures such as vaults, foundation walls and concrete pads


Electromagnetic works by transmitting an electromagnetic frequency through the conductive material of an underground utility. This utility locating method can be highly effective for known utilities that are metallic or have been installed with a tracer wire. Depending on the site and the utility to be located we can apply a signal through various methods:

  • Direct Connection; a signal lead cable from the transmitter is attached to a piece of utility hardware that is connected to the target line. A ground lead attached to a grounding stake allows the signal to return to the transmitter, thus setting up an electric circuit;
  • Induction clamp; the clamp is placed around conduits or exposed cables (generally used for tracing electrical or telecom cabling). Coils of wire in the clamp are energized by the transmitter and produce a magnetic field that is transferred onto the cable;
  • Straight Induction; no direct connection to utility, the transmitter is placed over the position of the suspected utility and the signal is induced onto the target line by.

Island Underground Surveys can give you the best information possible to get your job done. Contact us today for more information or to schedule a locate.