Description

Organizes trace headers into cross-spreads — the group of all traces sharing the same source line and receiver line — and adds the header fields needed to display and process data in the cross-spread domain (a common QC and noise-attenuation domain in 3D land and OBN surveys). For each cross-spread it computes a center position and assigns source and receiver index numbers, and it can optionally fill in placeholder traces for source/receiver station positions that exist in the acquisition grid but have no live trace, producing a complete, regular cross-spread matrix for display and analysis.

Input data

Input trace headers

The trace header set to organize into cross-spreads. Each trace must already carry valid source and receiver line/SP geometry.

Bin grid

The project bin grid, used to look up ground elevation for synthesized placeholder traces. Only needed (and only shown) when Create missing traces is enabled.

Grid items

The regular source and receiver line/SP acquisition grid definitions (typically produced by a geometry QC module such as SP correction). Used to identify which source and receiver station positions are missing from the live data when synthesizing placeholder traces.

Parameters

Create missing traces

When enabled, the module fills in the cross-spread matrix by synthesizing empty placeholder traces for every source/receiver station combination defined in the acquisition grid that has no corresponding live trace, positioned at the midpoint between the missing source and receiver stations. This gives every cross-spread a complete, regular source-by-receiver matrix, which is useful for display, QC and algorithms that expect a fully populated grid. When disabled, only the traces actually present in the input are output. Enabling this option requires the Bin grid and Grid items inputs.

Default: Off.

Output data

Output trace headers

The trace headers grouped and enriched for the cross-spread domain. New header fields are added recording the cross-spread number, the cross-spread center X/Y position, the source and receiver index within the cross-spread, and the receiver/source station ("picket") positions, so the data can be sorted and displayed by cross-spread. If Create missing traces is enabled, additional zero-fold placeholder traces are included to complete the source-by-receiver matrix.

References

Vermeer, G. J. O., 2002, 3-D Seismic Survey Design: Society of Exploration Geophysicists.