4984 Project 1. The principle of GPR consists on transmitting electromagnetic waves and receiving the reflected signals.
Reflections occur at interfaces between different materials.
Thus if the relative dielectric constant is known, the depth of the reflective interface may be found from the measured return signal time. A sequence of trigger pulses is generated in the control unit by the radar circuitry. The trigger pulses are sent through the control cable to the antenna. In the antenna, each trigger pulse is transformed into a bipolar transmit pulse. Energy is transmitted in a conical pattern into the subsurface.