Geometry

We set out our 60 geophones in a $8\times8$ array with 4 empty locations. Geophone spacing was 20 cm in both X and Y directions. We then recorded shots at 23 locations spaced 40 cm apart, keeping the receiver geometry fixed. Shots consisted of 7 pings with a small hand-held hammer on a metal plate. Figure 2 shows a photograph of the study area, and the receiver array. Source and receiver geometry is shown in the left panel of Figure 3.

 

monterey
Figure 2 Photograph of study area and very high-resolution 3-D receiver array.

This acquisition geometry led to a CMP spacing of 10 cm, as shown on the right panel in Figure 3. The fold map (Figure 4) is somewhat irregular as may be expected given the low number of shots; however, the fold ranges from about 6 to 13 in the main diagonal swath, which is 0.8 m wide and 1.2 m long.

 

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Figure 3 The left panel shows shot (*) and receivers ($\circ$) locations. The right panel shows CMP locations.

 

fold Figure 4 Fold chart with 0.1 cm bins.