Radar signal pre-processing to suppress surface bounce and multipath

A computer-readable storage device storing computer-executable instructions for controlling a computing device to suppress effects of extraneous signals in return signals acquired by receivers from ground-penetrating radar signals emitted by transmitters operating in a multistatic mode, by a method, the method comprising:

• receiving return signals for each transmitter and receiver pair at each of a plurality of down-track locations;
• and
• for each current return signal,
• calculating an estimated background signal for the current return signal based on an estimated background signal for a prior return signal for a prior down-track location that has a similar air gap to the current return signal and an estimated gain and bias adjusted return signal for the prior return signal;
• calculating a gain and bias adjusted return signal for the current return signal;
• and
• calculating an estimated foreground signal for the current return signal based on a difference between the gain and bias adjusted return signal for the current return signal and the estimated background signal for the current return signal.

A computing device for suppressing effects of extraneous signals in a current return signal acquired by a receiver from a signal emitted by a transmitter, the signal being a ground-penetrating radar signal emitting towards the ground, the current return signal having a plurality of samples corresponding to times at which the return signal was sampled by the receiver, the current return signal collected at current down-track location, comprising:

• a component that generates an adaptation parameter based on disparity between an estimated background signal for a prior return signal for a prior down-track location that has a similar time delay between when the transmitter emits the signal and a return signal that bounces off a surface is acquired by the receiver as the current return signal and an estimated gain and bias adjusted return signal for the prior return signal;
• a component that generates an estimated background signal for the current return signal as a combination of the estimated background signal for the prior return signal and the estimated gain and bias adjusted return signal for the prior return signal, the combination being weighted by the adaptation parameter;
• a component that generates a gain and bias adjusted return signal for the current return signal;
• and
• a component that generates an estimated foreground signal for the current return signal based on a difference between the gain and bias adjusted return signal for the current return signal and the estimated background signal for the current return signal.