The cross-correlation imaging condition requires that the source and receiver wavefields should be synchronously available. Opposite propagation directions of those wavefields, nevertheless, pose a challenge between computer memory and computation complexity. We present a local cross-correlation imaging condition, a transition between the excitation amplitude and the crosscorrelation imaging conditions, for reverse time migration (RTM) to relax the limitation. For one spatial node, we merely correlate the forward and backward records in a local time window, which is corresponding times of the direct wave at this node during the source wavefield simulation. This method only demands to store a complete waveform of the direct wave in each spatial node’s record, and it does not require remodeling the source wavefield. We demonstrate this method on two-layer and BP synthetics. Numerical simulations show that this method can generate high-accuracy images and reduce the storage cost significantly. It may be widely used in RTM and other adjoint-state methods.
Presentation Date: Tuesday, October 13, 2020
Session Start Time: 1:50 PM
Presentation Time: 1:50 PM
Location: Poster Station 2
Presentation Type: Poster
