SEGJ Technical Conference

Phase velocity estimation by multichannel analysis of surface waves with continuous wavelet transform

Abstract To improve the stability of phase velocity estimation using multichannel analysis of surface waves (MASW) in laterally heterogeneous structures, we propose an approach introducing continuous wavelet transform (CWT) into MASW. In our approach, we first construct CMP cross-correlation (CMPCC) gathers from multichannel and multishot data. We then estimate group velocity dispersion curves using CWT for each CMPCC gather. Phase velocity dispersion curves are finally obtained by using phase information at the arrival times of group waves to reduce the influence of noise due to lateral heterogeneity. Our numerical and field examples demonstrated that our proposed approach works well to improve the stability of phase velocity estimation near the lateral heterogeneity. Therefore, our approach would contribute to improving the applicability of MASW in heterogeneous structures such as geothermal fields.