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Stereo tomography multiline (test) jointly updates depth-domain velocity models for multiple 2D seismic lines using stereo tomographic inversion. All input lines share a common inversion framework so that velocity updates are laterally consistent at line crossings. This module differs from Stereo tomography 3D in that it works with a set of 2D lines rather than a true 3D volume, and it provides additional options to enforce or suppress the multiline constraint, substitute the constrained area back to the original model, and include or exclude lateral side constraints. This module is marked as a test version.
Multi-line tomo dataset assembled by Set multi line tomo item. Contains tomo parameters for all lines to be jointly inverted.
Optional horizon picks used as hard geological constraints to bound the velocity update zone within a specific stratigraphic interval.
Container grouping horizon-based layer constraint settings.
Top horizon of the constrained velocity update zone.
Bottom horizon of the constrained velocity update zone.
When enabled, restricts velocity updates to the zone between Layer from and Layer to. Default: off.
When enabled, disables the multiline intersection constraint so each line is inverted independently using the legacy single-line algorithm. Default: off. Enable for backward compatibility with older workflows or to diagnose multiline constraint artefacts.
When enabled, applies lateral side constraints to regularise velocity updates at the edges of the inversion grid. Default: off. Useful for preventing edge artefacts in areas with sparse data coverage.
When enabled (default), the velocity values in the constrained horizon zone are replaced with the values from the original input model after each iteration, preventing the inversion from updating velocities inside already-resolved intervals. Disable to allow the inversion to modify velocity in all zones including those bounded by horizons.
Multi-line weighting factor controlling the strength of inter-line consistency constraint relative to single-line data fit. Default: 1.
Processing datum elevation (m) read from the input data (not editable).
Velocity (m/s) used to fill the datum-to-topography interval in the output model. Default: 0 m/s (do not fill).
Number of outer tomographic update cycles. Default: 3.
Ray tracing time step (s). Default: 0.01 s.
Number of localisation sub-iterations per global iteration. Default: 10.
Number of LSQR iterations per global iteration. Default: 5.
Weight of the spatial smoothness regularisation in the inversion. Default: 100. Higher values produce smoother models.
Standard deviation multiplier for outlier classification. Default: 3.
Global iteration from which outlier rejection is applied. Default: 1.
Maximum depth (m) of the output model. Default: 4000 m.
Minimum (surface) velocity (m/s) of the initial gradient starting model. Default: 1500 m/s.
Maximum (base) velocity (m/s) of the initial gradient starting model. Default: 5000 m/s.
Initial inversion grid cell size in the X direction (m). Default: 500 m.
Initial inversion grid cell size in the Y direction (m). Default: 500 m.
Extra boundary margin (m) added to the inversion grid around the survey footprint. Default: 2500 m. Prevents edge effects in the velocity model near the survey boundary.
Depth sampling interval (m) of the output velocity model. Default: 15 m.
When enabled, computes an alternative cost diagnostic alongside the main inversion misfit. Default: off.
Grid refinement factor applied between global iterations. Default: 0.5 (halves the grid cell size each iteration). Range: 0.1–5.
Spatial smoothing factor applied to each velocity update. Default: 1.
Container grouping LSQR solver convergence parameters.
Maximum condition number limit for the LSQR solver. Default: 10000.
Percentage of maximum iterations used as an early stopping check. Default: 70.
LSQR atol convergence tolerance. Default: 0.000001.
LSQR btol convergence tolerance. Default: 0.000001.
Container grouping parameters that filter tomo data points before inversion.
Maximum tomo data points per line. Default: 5000. Reduce if memory errors occur.
Minimum event incidence angle (degrees) to include. Events below this angle are rejected.
Maximum event incidence angle (degrees) to include. Default: 90 degrees.
Controls whether events in the Min/Max angle range are kept or removed. Default: None.
Decimation factor for tomo data points. Default: 1 (no decimation).
Selects whether the inversion runs on CPU or GPU.
Configuration for distributed (cluster) execution.
Minimum gathers per chunk during distributed execution.
When enabled, restricts CPU threads per node to the Number of threads value.
Optional text appended to the distributed job name.
When enabled, applies the Affinity mask for CPU core assignment.
CPU affinity mask used when Set custom affinity is enabled.
Maximum CPU threads used during execution.
When enabled, this module is bypassed and data passes through unchanged.
Intermediate per-iteration depth velocity model gathers for convergence monitoring.
Final updated depth velocity model at the common processing datum. Save via Save seismic by gather for use in the next migration iteration.
Final updated velocity model in the topography datum reference frame.
The multi-line tomo item updated with the new velocity model, ready for use as input to the next iteration of Set multi line tomo item and stereo tomography.
Depth velocity model for the currently active line, available for interactive display during processing.
Number of tomo data points used after filtering and decimation.