GPR operates on the principle of transmission, reflection, and detection of short duration electromagnetic pulses from a transducer that is moved across the surface.

The energy travels through the concrete and is reflected back to the receiving antenna from any subsurface discontinuities, such as voids, metallic and non-metallic structures, geological strata, etc.

The time the electromagnetic pulse takes to travel from the transmitting antenna to the target and back to the receiving antenna is continuously recorded. The collected data are displayed in real-time on a computer.

The data can be interpreted on-site or digitally processed to produce plan-view maps, cross-sectional images, and three-dimensional models.