Time-Delay Estimation Based on an Enhanced Modified MUSIC With Co-Prime Frequency Sampling for Rough Pavement

In cases involving a rough interface, the echo frequency behavior of ultrawideband ground-penetrating radar (UWB-GPR) approximates a nonlinear Gaussian function. This characteristic leads to poor robustness and high computational complexity in existing modified MUSIC (Mod-MUSIC) methods. To address this challenge, this letter proposes an enhanced Mod-MUSIC (E-Mod-MUSIC) approach to mitigate the interference of false peaks, thus enhancing robustness. Furthermore, to reduce computational complexity while maintaining high estimation accuracy comparable to dense uniform frequency sampling (UFS) structures, a distributed co-prime frequency sampling structure (DCFSS) is used with E-Mod-MUSIC. Numerical simulations with different scenarios show the effectiveness of the proposed method.