Fig. 9

Synthetic test of slant stack, SPAC, and FJ methods. We assumed an ambient seismic wave field with a slowness of 0.3 s/km. a Station distribution. b Histogram of separation distance between station pairs. c Plot in slowness domain: slant stack, variance reduction of the SPAC method, and the FJ spectrum as a function of slowness. The noise is assumed to be 3% of the signal