Imaging by Forward Propagating the Recorded Data - An Analysis

We study the concept of forward propagating the recorded data in prestack imaging of acoustic media by analyzing the contributions of the main components of the data, which are the direct arrivals, primaries, and multiples. In reverse time migration (RTM), this implies correlating the forward extrapolated recorded data wavefield with its reversely extrapolated version prior to applying the zero-time imaging condition. The interaction of the data components with each other in the cross correlation process will image the primaries, and the multiples, as well as introduce crosstalk artifact terms. However, some of these artifacts are present in the conventional RTM implementation and they tend to be relatively weak. Forward propagating the direct arrivals is equivalent to forward propagating a source, and they tend contribute the majority of the imaging energy. Thus, depending on how we alter the forward propagated data to, for example, extract certain components, we can control the image results. Despite the potential crosstalk terms in forward propagating the recorded data, it can provide results equivalent to the conventional approach.