What is GPR?
Ground Penetrating Radar or GPR for short is based on a principal called Electromagnetic Reflection (EMR). This is an impressive term but the theory of GPR is not complicated.
The GPR equipment sends very small pulses of energy into the survey area, such as concrete. This energy wave reflects off targets and is sent back to the GPR receiver. The images are then recorded on the GPR monitor for displayed. This principal is similar to an echo off a canyon wall.