Algorithm for the Restoration of Clipped GPR Amplitudes

It is common in Ground Penetrating Radar (GPR) imagery to have missing or corrupted traces. This can be either due to obstacles, noise, technical problems or economic considerations. Antenna-ground coupling is another reason for clipped amplitudes in GPR data. Most commercially available software use the famous "rubber band interpolation", which uses the spline polynomial to undo the clippings. This method is a simple polynomial based interpolation which performs declipping without considering any prior knowledge about the signal. In this paper, a modified Projection on convex set (POCS) method hybird with Non uniform fast Fourier transform (NFFT) is adopted for reconstruction of clipped amplitudes. Restoration of bandlimited GPR data which has undergone amplitude clipping is studied. This algorithm is tested on synthetic and then real clipped GPR data. To study the effectiveness of the technique, results obtained are compared with industry standard spline interpolation.