A clutter suppression/SAR focusing algorithm for landmine detection with GPR

Abstract

In this paper we propose a new algorithm for enhancement of plastic cased antipersonel mines detection using a video-impulse GPR. The algortihm is implemented as a non-linear signal processor integrated with a SAR focusing procedure. The new algorithm constructs SAR-like image of the subsurface at each point summing the outputs of the signal processor. The signal processor searches for presence of reference waveform in raw !D GPR echo-returns and compresses in time all responses similar to it. Simultaneously, the responses with different waveforms, which presumably correspond to clutter, are suppressed. The shape of the predefined reference waveform depends on the angle at which the point being imaged is illuminated. This algorithm is integrated into an automated data processing and mine detection scheme generating a detection list. The reference waveform and other algorithm parameters are determined from training datasets acquireed in a controlled environment. The performance of the new algorithm is compared against the performance of the sequence of the signal processor without angle dependency and SAR and agianst a scheme involving a cross-correlation of the input with the same reference wavelet. The improvement achieved by the suggested algorithm is demonstrated in terms of RTOC curves.