f An example of walkaway processing based on spectral matrix filtering

Two walkaway seismic profiles were recorded in the vicinity of a vertical well. The first profile, oriented north-south, was composed of 103 offset VSPs. The maximum source-offset was 800 m. The average distance between two source positions was 10 m. The second profile, oriented east-west, was composed of 60 offset VSPs with a maximum offset of 500 m. The source was a vibroseismic source. The receivers in the vertical well were 15 permanent vertical sensors, clamped in the 540-680 m depth-interval. The distance between two permanent sensors was 10 m.