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Min offset reg (Minimum Offset Regularisation) fills gaps in the near-offset coverage of a 3D survey by borrowing traces from spatially adjacent CMP bins. For each selected bin that lacks traces at offsets below the user-defined Minimum offset threshold, the module searches neighbouring bins within the specified Aperture, finds a donor bin that contains traces at the missing offsets, and clones those traces into the target bin with corrected source and receiver coordinates. The output is a new seismic file containing the regularised near-offset traces.
The module is intended as a pre-processing step to reduce acquisition footprint caused by uneven near-offset distribution, particularly in areas affected by obstacles or sparse receiver coverage. Use the interactive map to select only those bins that genuinely require regularisation, avoiding unnecessary modification of well-sampled areas.
Handle to the SEG-Y file containing the full seismic dataset. The module reads trace amplitudes from this file for all selected donor and target bins.
Trace header table for the full dataset. The module uses the bin assignments, offset values, and source/receiver coordinates from these headers to build the geometry map and to locate donor traces for each target bin.
3D bin-grid definition providing the inline/crossline layout of the survey. The fold map, minimum-offset map, and maximum-offset map stored in the bin grid are displayed in the QC views and used to identify bins that require regularisation.
Path and filename (GSD format) for the output regularised dataset. The regularised near-offset traces are written to this file. If Save all data is enabled, the full original dataset is also appended to this file.
Maximum search radius (in metres) within which donor bins are sought for each target bin. Default: 1000 m. The module searches all bins within a square of ±Aperture around the target in both the inline and crossline directions, then sorts them by distance to find the closest suitable donor. Increase this value in surveys with sparse geometry; decrease it to limit the spatial borrowing distance and preserve local near-offset character.
Target minimum offset, in metres. Default: 0 m. Only bins whose actual minimum offset exceeds this threshold are candidates for regularisation. Set this to the desired minimum offset that all bins should achieve after regularisation. Bins that already have traces at or below this offset are skipped.
Offset step used to divide the missing near-offset range into sub-intervals for individual trace borrowing, in metres. Default: 200 m. For each step interval [offset, offset + StepOffset] within the missing range, the module independently searches for a donor trace. Smaller step values produce a more densely sampled near-offset range but increase computation time and the number of synthetic traces added.
When enabled (default: on), all original traces from the input dataset are appended to the output file after the regularised near-offset traces have been written. When disabled, only the newly inserted near-offset traces are written. Enable this option to produce a complete output dataset ready for further processing without a separate merge step.
When enabled (default: on), cloned traces are only written if both the translated source and receiver positions fall within the survey fold boundary (i.e., areas with at least one real trace). This prevents regularised traces from being placed outside the acquired area, which could introduce edge effects. Disable this option only if you need to extend coverage beyond the original survey boundary.