Technical term – GPR, Ground Penetrating Radar
GPR, Ground penetrating Radar or ground radar is an electromagnetic reflection technique to create images of what’s under the soil surface. A transmission solenoid sends out high frequency radio pulses into the ground, which are reflected by ‘di-electric contrasts’ (e.g. separation between soil layers, objects, etc.). In general practice, measurements are carried out with the GPR in motion, emitting a pulse about ten times per second. It registers the run time of the reflected pulses (and thus the depth of the reflector). Simultaneously, a GPS system registers the position of the GPR. All these data result in a radargram, which can be interpreted for the presence of layer separations, objects, conducts, etc.