Impulse response

Figure  presents the summation surfaces [equation (1)] for an impulse response at a depth of 500 m, a P-velocity of 3000 m/s, an S-velocity of 1500 m/s, and an in-line offset of 3000 m. The left panel shows the single-mode PP summation surface, and the right panel shows the converted-mode PS summation surface. Similarly, Figure  shows the spreading surfaces; that is, the theoretical solution for depth of equation (1), Appendix A shows the calculations. The left panel presents the single-mode PP spreading surface, the center panel shows the converted-mode PS spreading surface, and the right panel compares the contour lines for both spreading surfaces.

Figure  shows the common-azimuth impulse response for a constant P-velocity of 2500 m/s, and a constant S-velocity of 1250 m/s, and an in-line offset of 200 m. The left panel exhibits the response for the single-mode PP common-azimuth migration operator, and the right panel exhibits the response for the converted-mode PS migration operator.

 

impcheops Figure 1 Summation surfaces for a constant medium with a of P-velocity of 3000 m/s, an S velocity of 1500 m/s, and an offset of 2 km. Left: PP summation surface. Right: PS summation surface.

 

imptheory
Figure 2 Spreading surfaces for an impulse at 0.320 s PP traveltime and 0.480 s PS traveltime, an offset of 200 m, and assuming constant P-velocity of 2500 m and S-velocity of 1250 m. Left: PP spreading surface. Center: PS spreading surface. Right: contour lines comparison from both spreading surfaces.

 

imp.resp Figure 3 Impulse response for a point diffractor at 0.320 s PP traveltime and 0.480 s PS traveltime, and in a constant-velocity medium with a P-velocity of 2500 m/s and S-velocity of 1250 m/s. Left: presents the single-mode PP. Right: panel presents the converted-mode PS.