Introduction to special section: Ambient noise

摘要

Many efforts of geophysical processing have traditionally been devoted to the separation, attenuation, and elimination of noise from seismic acquisition data. However, one geophysicist's noise is another geo- physicist's signal. Aki (1957) formulated the spatial autocorrelation method, which became a widely used tool in site investigations for determining surface-wave phase velocities from microtremors. Later, Claerbout (1968) proposed to correlate passive seismic recordings to simulate seismic reflection data.