Active surface waves acquired with conventional and landstreamer setup along railway earthwork

For conventional setup : seismic linear arrays composed by 96 geophones spaced at intervals of 0.25 m, with a length of 23.75 m. The setup was positioned on the cess (i.e. the track side). Seismic data were acquired by vertically striking a metal plate with a sledghammer placed in-line, 0.125 m away from the first (direct shot) and last (inverse shot) geophones. Waves propagation along the setup was recorded for 2 s with a sampling interval of 0.5 ms (i.e. sampling rate of 2 kHz) and a pre-triggering delay of -0.02 s. For landstreamer stup : seismic linear arrays composed by 48 geophones spaced at intervals of 0.5 m, with a length of 23.5 m. The setup was positioned on the track and the 47 deployement covered a section 300 m long. Seismic data were acquired by weight drop placed at 9 m of the last geophone. Waves propagation along the setup was recorded for 1.5 s with a sampling interval of 0.125 ms (i.e. sampling rate of 8 kHz) and a pre-triggering delay of -0.01 s.