Adaptive filtering with non-stationary helical filters

To handle the inherent non-stationarity of seismic data, we estimate a filter bank of non-stationary filters using helical boundary conditions (). This approach has been successfully utilized by () to attenuate surface-related multiples. We use a NLCG solver with the 1#1-norm and a standard conjugate gradient solver with the 312#312-norm. The filter coefficients vary smoothly across the output space thanks to a preconditioning of the problem (). In the following results, the non-stationary filters are 1D. We estimate the same number of coefficients per filter with the 312#312- and 1#1-norm.