Relative Time-Difference Measurement of Array Records of Teleseismic <i>P</i> -Wave Using Phase-Only Correlation

Abstract This study introduces the integration of phase-only correlation into the multichannel cross-correlation (MCCC) framework to enhance relative time-difference measurements for teleseismic P-wave array records. When near-receiver structural heterogeneities distort waveforms, conventional cross-correlation methods often suffer from reduced precision. Our approach exploits phase-only correlation to mitigate amplitude-related distortions while preserving phase coherence. Synthetic tests with progressively increasing complexity, from noise-contaminated signals to wavefields fully distorted by this complex near-station structure, demonstrate consistent improvement in time-difference precision compared to conventional methods. Importantly, a synthetic tomography experiment validates the method’s practical advantage over conventional methods: velocity anomalies obscured by conventional measurements are successfully resolved using our technique. These results establish phase-only correlation as a robust enhancement to MCCC processing, particularly valuable for seismic arrays operating in geologically complex regions. By improving delay-time measurement fidelity, this method advances the reliability of teleseismic imaging for subsurface characterization.