Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA Full fold in-line Concept... process full-fold original and decimated-and-interpolated datasets and compare final stacks also compare and analyse at other stages (but how?)

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA Source Shot interval Source depth Source separation Group interval Cables Cable depth Cable separation Cable length Minimum offset Maximum offset Orientation dual air-gun 12.5 m flip-flop 3.55 m m 6.25 m m 37.5 m 2000 m 0 m 2000 m east-west Captain dataset

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA Full fold in-line Reduce initial data volume –drop one source –group interval 12.5 m –6 swaths, 48 CDP lines Process A Delete every 2 nd shot from 2 out of 3 swaths Interpolate missing shots Process B

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA full fold 450 m 300 m

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA Technical challenge Simple interpolation did not work as well as we would like at the highest frequencies. in-line aliasing cross-line separation At 50m shot spacing, aliased at 20 Hz for 2000 m/s

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA In-line aliasing Captain is broad band – 80 Hz plus The original data is 25 m shot - aliased at 40 Hz for 2000 m/s At 50 m shot spacing - aliased at 20 Hz 2000 m/s

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA Cross-line separation Captain is high resolution with 9.3 m cross-line CDP If it were shot triple-source, the cross-line spacing between centre, full-fold sources would be 170 m. We are trying to interpolate cross line 450 m. This corresponds a 25 m cross line CDP.

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA full fold 450 m 300 m

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA 450 m

Click to edit Master text styles –Second level Third level –Fourth level »Fifth level Click to edit Master text styles –Second level Third level –Fourth level »Fifth level ISSSA Two stage scheme low pass & run conventional scheme high-pass & run conventional scheme, but with low pass result also used as input