A key part of project planning is knowing exactly what lies beneath the surface at a site. This case study demonstrates a common use of GPR.

Ground Penetrating Radar (GPR) use radio waves to non-destructively locate objects and subsurface structures in materials like soil, rock, concrete, asphalt, wood and water.
Sensors & Software Inc. is a GPR manufacturer that is recognized worldwide for its commitment to technical excellence, continuous innovation and responsive customer service. You will find their products in use for numerous applications by engineers, miners, archaeologists, geologists, as well as military, security and law enforcement personnel.
A major application area for GPR is the detection and mapping of buried utilities. In the following, we address the field methodology and related GPR instrumentation characteristics.

Why Use GPR for Utility Locating?

The tools and methods of locating buried utilities are quite diverse. The most common approach is energizing metal pipes and cables with electric currents and using a magnetic-field sensor to detect the current. Provided the target can be exposed for connection or current can be induced, sufficient current flows on the target, and the detector is sufficiently sensitive to detect the magnetic field created by the current, then this technique works well and is very cost effective.
When access is difficult, electrical current does not flow (i.e. non-metallic element or broken connection), or external noise makes detection impossible, GPR provides an alternative. GPR provides its own source of energy, detects both metallic and non-metallic objects, as well as disturbed soil conditions and other buried structures.

Subsurface Reflections by Peter Annan