We present a new technique that mitigates the effects of unbalanced
amplitudes that vary relatively smoothly along the locations and dips
of the predicted multiples. Our approach is complementary to windowed
matched-filtering techniques (Verschuur and Berkhout, 1997), which offer limited
control over window-to-window variations amongst the estimated matched
filters. Our method also avoids relative expensive multiple
predictions required by iterative SRME. To offer better control over
these variations, errors in the single-window SRME-predicted multiples
are modeled by a zero-order pseudo-differential operator, a kind of
spatially varying dip filter, which can be well approximated by a
diagonal curvelet-domain scaling (Herrmann et al., 2007c). This
scaling is estimated from the input data and predicted multiples by a
nonlinear optimization procedure, during which smoothness amongst
neighboring curvelet coefficients is imposed. This smoothness amongst
the curvelet coefficients ensures a scaling that is well-behaved
spatially and as a function of the dip. This approach employs the
adaptability of curvelets, while the smoothness constraint prevents
overfitting of the data, which can lead to a loss of primary
energy. Although distinct, our approach is similar to recent work in
migration-amplitude recovery, where scaling methods with smoothness
constraints have been proposed (Symes, 2007; Guitton, 2004). This
letter builds explicitly on a curvelet-based approach to this problem
introduced by Herrmann et al. (2007c).