Time-delay Estimation of Coherent GPR Signal by Using Sparse Frequency Sampling and IMUSIC Method

Time-delay estimation (TDE) using the ground penetrating radar (GPR) signal contains important information about the stratified media structure. TDE trend to be challenging in the scenarios of coherent, overlapping signals and limited bandwidth of GPR. This paper proposes a decoherence method based on improved multiple signal classification (IMUSIC) with a specified symmetric sparse sampling structure for TDE in the thin pavement and limited bandwidth GPR scenarios. Compared with uniform sampling, this method is sensitive to overlapping and weak multiple echoes, with fewer sampling points and lower computational complexity. Simulation results demonstrate the advantages of the proposed method over various existing methods including the interpolation method and Orthogonal matching pursuit (OMP) when dealing with overlapping and coherent signals.