1. A method comprising: processing seismic data indicative of samples of at least one measured seismic signal in a processor-based machine to, in an iterative process, determine basis functions which represent a constructed seismic signal; and in each iteration of the iterative process, selecting another basis function of the plurality of basis functions, the selecting comprising: based at least in part on the samples and a current version of the constructed seismic signal, determining a cost function; and interpreting the cost function based at least in part on a predicted energy distribution of the constructed seismic signal to select said another basis function.