Seismic applications of forward interpolation

For completeness, I conclude this section with two simple examples of forward interpolation in seismic data processing. Figure  shows a 3-D impulse response of Stolt migration Stolt (1978), computed by using 2-point linear interpolation and 8-point B-spline interpolation. As noted by Ronen (1982) and Harlan (1982), inaccurate interpolation may lead to spurious artifact events in Stolt-migrated image. Indeed, we see several artifacts for the image with linear interpolation (the left plots in Figure .) The artifacts are removed by a more accurate interpolation method (the right plots in Figure .)

 

stolt
Figure 25 Stolt migration impulse response. Left: using linear interpolation. Right: using seventh-order B-spline interpolation. Migration artifacts are removed by a more accurate forward interpolation method.

Another simple example is radial trace transform Ottolini (1982) Figure  shows a land shot gather contaminated by nearly radial ground-roll. As discussed by Claerbout (1983), Henley (1999), and Brown and Claerbout (2000), one can effectively eliminate ground-roll noise by applying radial trace transform, followed by high-pass filtering and the inverse radial transform. Figure  shows the result of the forward radial transform of the shot gather in Figure  in the radial band of the ground-roll noise and the transform error after going back to the original domain. Comparing the results of using linear and third-order B-spline interpolation, we see once again that the transform artifacts are removed with a more accurate interpolation scheme.

 

radialdat Figure 26 Ground-roll-contaminated shot gather used in a radial transform test

 

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Figure 27 Radial trace transform results. Top: radial trace domain. Bottom: residual error after the inverse transform. The error should be zero in a radial band from 0 to 0.65 km/s radial velocity. Left: using linear interpolation. Right: using third-order B-spline interpolation.