Patent ID: 8289201

Claim:
A detection system for detecting objects having electrical non-linear characteristics located underground, the detection system comprising: a transmitter unit for transmitting into a ground a first pulsed radio frequency signal at a first frequency generated by a first transmitter and a second pulsed radio frequency signal at a second frequency generated by a second transmitter; and a receiver for monitoring for a response radio frequency signal having a third frequency equal to a difference between the first frequency and the second frequency, wherein the response radio frequency signal is generated by an object having non-linear conductive characteristics in response to receiving the first pulsed radio frequency signal at the first frequency and the second pulsed radio frequency signal at the second frequency; and a processor for controlling an operation of the transmitter unit and the receiver, wherein the processor is connected to the transmitter unit and the receiver, and wherein the object is detected when the response radio frequency signal is detected by the receiver.