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QC 2D MF Geometry is a quality-control module that analyses and displays the geometry of a 2D Multi-Focusing (MF) acquisition layout. It computes fold and coverage statistics for each CMP bin along the line and produces a set of interactive graphs that allow you to verify whether the survey geometry is suitable for Multi-Focusing processing before committing to a full run.
The module operates in two modes. In standard mode (no Virtual Geometry trace headers connected), it computes the MF fold, average source fold, average receiver fold, average CMP deviation from the line, bin azimuth angles, and bin topography for every bin along the 2D line. In Virtual Geometry mode (when a Virtual Geometry trace-header collection is connected), the module evaluates how well each virtual source-receiver pair would be covered by the available real traces under the MF aperture, and displays the resulting fold versus offset as a scatter plot.
Run this module after loading and applying geometry but before running the Multi-Focusing engine. Use the output graphs to detect gaps in coverage, asymmetric source/receiver fold, or excessive CMP deviation that could degrade MF image quality.
The 2D stack-line bin-point collection that defines the CMP positions along the seismic line. This is the reference geometry against which fold and deviation statistics are computed. Connect the bin-point vector produced by the geometry application or binning step.
The sorted trace-header index that provides the source, receiver, offset, and CMP information for all input seismic traces. This index is used to look up which traces fall within the Multi-Focusing aperture of each bin. Connect the gather-index vector produced by the header-sorting or geometry-application step.
The Multi-Focusing table parametrization object that defines the inline aperture, crossline aperture, and maximum offset to be used when gathering traces into each MF super-gather. These parameters determine how large the neighbourhood around each CMP is, and therefore how many traces contribute to the fold count. Connect the same MF Table Parametrization object that will be used in the Multi-Focusing processing flow so that the QC results reflect realistic processing conditions.
This optional parameter group enables Virtual Geometry mode. When the Trace headers sub-item is connected and the Aperture value is set, the module switches from standard geometry analysis to virtual-geometry fold evaluation. Leave this group unconnected to use the standard mode that produces bin-by-bin fold and deviation graphs.
A trace-header collection representing the virtual (synthetic) source-receiver pairs whose coverage is to be evaluated. When connected, the module calculates, for each virtual trace, how many real input traces fall within the MF aperture around that virtual midpoint. This is useful for evaluating the feasibility of a planned virtual-geometry acquisition or regularisation scheme. If this item is not connected, the module runs in standard mode.
The reference aperture radius (in metres) used in Virtual Geometry mode to search for real traces that match each virtual source or receiver position. A real trace is considered a match if both its source and receiver positions lie within this distance of the corresponding virtual positions. The default value is 300 m. Increase this value if the real geometry is sparse relative to the virtual geometry; decrease it to apply a stricter matching criterion. This parameter has no effect when Trace headers is not connected.