Combining forward-scattered and back-scattered wavefields in velocity analysis |
wemva30tv,wemva30bp
Figure 6. The true slowness model with a cosine perturbation (a) and the inversion results using low-frequency back-scattered FWI (b). |
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Figure 7(a) shows the results of correlation-based WEMVA. As shown earlier, the gradient has low vertical resolution. Also, the anomaly has negative side-lobes. However, the amplitude of the anomaly is much stronger than with back-scattered FWI, and the kinematics of the reflector below converges much faster. Figure 7(b) shows the results of the combined gradient. The amplitude of the anomaly is even stronger and is closer to the true anomaly than is the WEMVA inversion. Furthermore, the side-lobes are much weaker, and the model has much better vertical resolution. Notice that figures 6(b), 7(a) and 7(b) have different color scales.
wemva30fp,wemva30fbp
Figure 7. Slowness inversion results using (a) correlation-based WEMVA inversion and (b) the combined gradient. |
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Combining forward-scattered and back-scattered wavefields in velocity analysis |