Surface-Wave Imaging with Nonrandom Traffic Noise Sources

Abstract

We analyze the influence of nonrandom traffic noise sources on surface wave imaging. With nonrandom traffic noise sources in time (correlated sources), spurious signals are produced in the crosscorrelation functions. With nonrandom traffic noise sources in space (directional sources), phase velocities are overestimated from the retrieved surface waves. The retrieval of surface waves can be improved by stationary-phase segment selection, cross-coherence and stacking of the results from multiple traffic noise sources. Synthetic results demonstrate that cross-coherence and stacking of multiple traffic noise sources makes the source tend to be random distribution in time and suppresses the spurious signals in the crosscorrelation functions. Enhancing the stationary-phase contribution makes more accurate estimation of surface wave phase velocities.