sfspectra computes spectrum, the absolute value of the 1-D Fourier transform along the fast axis.

The following example from rsf/su/rsfkasper shows a seismic shot gather before and after high-pass filtering and the corresponding spectra computed with sfspectra.

sfspectra has only one option: all=. If all=n (the default behavior), the spectrum is computed separately for each trace. If all=y, the output is the spectrum averaged across all traces.

For a two-dimensional version, try sfspectra2. The following figures from jsg/seislet/lena show the infamous Lena image and the “seismic Lena” (after Chris Liner and David Monk)

and the corresponding 2-D spectra computed with sfspectra2

Previous programs of the month

• sfnoise
• sfgraph
• sfclip
• sfagc
• sfenvelope
• sfcontour
• sfsmooth