Suppression of multiples from complex sea-floor by a wave-equation approach
We present a new efficient wave-equation scheme for prediction and subtraction of water-layer multiples and peg-legs from an arbitrary 2D irregular sea-floor. The scheme accounts for both multiple reflections and diffractions. The method requires approximate knowledge of the sea-floor geometry. The predicted multiples are split into three terms, where each term contains multiple events which require the same amplitude correction. Therefore the method has much fewer problems with the adaptive subtraction of predicted multiples than the iterative SRME approach, especially for data from areas with a shallow sea-floor. In our scheme all source-side and receiver-side multiples of all orders are suppressed simultaneously in one consistent step (in one or a few time windows) from the Radon-transformed CMP or common shot gathers. The prediction of multiples both from receiver-side and source-side starts with data in the same domain, therefore no additional sorting or additional Radon transformations are required.