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Geometry of acquisition

The 3D dataset consists of 20 sail lines each with four active streamers and dual flip-flop shooting. The separation between streamers is 160 m and between receivers is 25 m. The shot interval is 37.5 m (between the flip and the flop). The minimum offset inline is 240 m and each streamer has 288 receivers for a maximum inline offset of 7175 m. Figure [*] shows the acquisition template. Figure [*] shows a map view of the subset of the shots used in this study. Although most sail lines were straight in the East-West direction, a few had significant curvature.

 
acq_sktch1
acq_sktch1
Figure 1
Sketch of the basic acquisition geometry
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shots_map
shots_map
Figure 2
Map view of the source locations.
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The strong currents present in the area caused significant feathering. Figure [*] shows an example for the sail-line at cross-line distance 11440 m. For most shots, the feathering was in the same South-North direction. Figure  [*] shows the fold of coverage that in some places depart significantly from its design value of 48. Some of the short source lines in Figure [*] we acquired as infill to avoid large coverage holes.

 
feathering
feathering
Figure 3
Map view of the receiver cables for one shot illustrating typical feathering.
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fold
fold
Figure 4
Fold map illustrating relatively uniform coverage.
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next up previous print clean
Next: Velocity model Up: Description of the data Previous: Description of the data
Stanford Exploration Project
5/6/2007