Reverse time migration (RTM) backscattering contains kinematic information that oan be used to constrain velocity models. The backscattering results from the correlation between forward and back propagated wave-fields originating at sharp interfaces, e.g. sediment-salt interfaces. The synchronization between these wave-fields depends on the sediment velocity section and on the correct interpretation of the sharp boundary. Therefore, we can use backscattering events along with reflection and diving waves to define a joint optimization problem for velocity model building. The gradient required for model optimization suffers from cross-talk, similar to the more conventional RTM images. In order to avoid the cross-talk, we use a directional filter based on Poynting vectors which preserves the components of the wavefield traveling in the same direction. Using backscattered waves for constraining the velocity in the sediment section requires defining the top of salt in advance, which implies a dynamic workflow for model building in salt environments where both sediment velocity and salt interface change iteratively during inversion.
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