FK

The FK group contains modules for frequency-wavenumber (F-K) domain analysis and noise suppression applied to 3D seismic volumes. Frequency-wavenumber processing operates by transforming seismic data from the time-space domain into the frequency-wavenumber domain, where acquisition-related noise patterns — such as footprint striping caused by regular source or receiver line spacing — appear as localized energy concentrations that can be isolated and attenuated while preserving the geologically meaningful signal.

Acquisition footprint is a systematic amplitude variation across a 3D seismic volume that reflects the geometry of the acquisition grid rather than subsurface geology. It typically appears as inline or crossline striping on time slices and can severely compromise AVO analysis, attribute extraction, and reservoir characterization. The modules in this group are designed to detect and remove such footprint patterns directly from post-stack or near-stack 3D volumes.

Modules in This Group

Foot print remove 3D — Removes acquisition footprint from a 3D seismic volume using frequency-wavenumber (F-K) domain filtering applied independently to each time slice. The algorithm transforms each time slice into the F-K domain using a 3D FFT, identifies footprint energy concentrated at specific wavenumbers associated with the acquisition grid spacing, and suppresses that energy using a wavenumber-domain mute function. Two independent sets of F-K filter parameters — one anchored at a shallow time and one at a deeper time — allow the filter shape to vary with depth, accommodating the fact that footprint character often changes with two-way travel time. An optional adaptive subtraction mode refines the footprint estimate before removal, which is useful when the footprint overlaps in wavenumber with legitimate reflector energy. An interactive slice-by-slice preview is available to tune the parameters before running the full volume.

Min Fold Foot print remove 3D — Removes acquisition footprint using an envelope-based approach rather than direct F-K muting. The algorithm first computes the instantaneous amplitude (envelope) and instantaneous phase of each trace using the Hilbert transform. The amplitude envelope is then reorganized into a 3D volume and spatially smoothed time-slice by time-slice using a 2D box filter applied independently along the inline and crossline directions. Smoothing suppresses the spatially periodic footprint pattern from the amplitude while preserving the broadband phase information. The output gather is reconstructed by multiplying the smoothed amplitude envelope by the cosine of the instantaneous phase, restoring the seismic waveform without the footprint-induced amplitude striping. This method is particularly effective when the footprint manifests primarily as a spatial amplitude modulation rather than as structured wavenumber energy.

When to Use FK Processing

Use the modules in this group when time slices through a post-stack 3D volume show regular amplitude striping aligned with the inline or crossline directions, or when fold maps reveal systematic under-sampling at certain bin positions. FK footprint removal is typically applied after stacking and before interpretation workflows such as seismic attribute extraction, acoustic impedance inversion, or AVO analysis — any workflow where spatially consistent amplitude is important. Both modules in this group process the data in the inline-crossline (spatial) domain on a time-slice basis, so the input data must be provided as a full 3D gather loaded into memory.