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Note: This module is deprecated. It is retained for compatibility with older projects. For new work, use the current MultiFocusing geometry modules.
This module computes the Multifocusing (MF) fold map for a 3D seismic survey. For each bin in the survey grid, the module counts all traces (CMP fold) that fall within a rectangular spatial aperture centred on that bin. This MF fold map expresses how many traces contribute to a multifocusing super-gather at each bin location — a key quality-control diagnostic when planning or evaluating a 3D multifocusing acquisition geometry.
The computation produces two visual outputs: a standard CMP Fold map derived directly from the bin grid, and a Multifocusing Fold map computed by summing the CMP fold values of all bins within the specified inline and crossline aperture. Both maps are displayed as 2D plan-view grids over the survey area. The inline and crossline aperture values directly control the size of the neighbourhood window and therefore the amplitude of the MF fold: larger apertures yield higher fold values at the cost of lower lateral resolution.
The 3D bin grid that defines the survey geometry for the multifocusing analysis. This grid specifies the spatial layout of all bins — their inline/crossline numbering, bin dimensions, and the CMP fold already assigned to each bin. The module reads the existing CMP fold from this grid to compute the MF fold map. The bin grid is typically prepared by an upstream geometry or binning module and must be fully populated before running this module.
This parameter group defines the spatial aperture window used when computing the Multifocusing fold. All four sub-parameters below belong to this group and together control the size and orientation of the neighbourhood from which traces are collected for each bin.
The half-width of the aperture window in the inline direction, expressed in metres. For each bin, the module accumulates CMP fold from all bins within this distance along the inline axis. The default value is 300 m. This value must be greater than zero; a value of zero or less will generate an error and halt processing. Increase this value to include more traces in the inline direction, which is useful for surveys with sparse inline sampling or where high MF fold is required. The practical limit is determined by the survey aperture and the inline bin spacing.
The half-width of the aperture window in the crossline direction, expressed in metres. For each bin, the module accumulates CMP fold from all bins within this distance along the crossline axis. The default value is 50 m. This value must be greater than zero; a value of zero or less will generate an error and halt processing. In 3D surveys with wide crossline spacing, increasing this value will yield a more uniform MF fold across the grid. Set both inline and crossline apertures to values consistent with the expected multifocusing operator size for the target depth.
The reference azimuth angle (in degrees) that defines the orientation of the inline axis of the aperture window relative to geographic north. This parameter allows the rectangular aperture to be rotated to align with the survey geometry when the survey lines are not oriented along the coordinate axes. The default value is 0 degrees. In the current implementation of this deprecated module, this parameter is defined but its effect on the fold calculation is limited — the aperture window is applied along the bin grid axes. Use the updated MultiFocusing geometry modules for full azimuth-aware fold computation.
The total angular aperture (in degrees) of the azimuth sector considered when selecting traces for the multifocusing super-gather. The default value is 90 degrees, which corresponds to a quarter-circle sector centred on the Initial Azimuth direction. A value of 360 degrees would include all azimuths. As with the Initial Azimuth, this parameter is defined in this deprecated module but the rectangular aperture algorithm does not apply azimuth-based trace selection — it uses the inline and crossline aperture distances directly. This parameter is retained for interface compatibility with newer modules.