Trim statics - Apply

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Trim statics - Apply

 

Description

Trim statics – Apply applies a set of pre-computed trace time shifts (trim statics) to a seismic gather to improve event alignment at the CMP level. Trim statics are small residual time corrections (typically ±5–25 ms) that remove trace-to-trace timing variations caused by near-surface velocity heterogeneity, inaccurate first-break picks, or residual moveout after NMO correction. The corrections are applied via high-quality 8-point or linear sinc interpolation to shift each trace by the required amount without introducing aliasing artefacts.

The time-shift values can be supplied either as a Trim data gather (a gather in which each trace stores its own shift value, typically computed by the Trim statics – Calculate module) or as a Trim file (a previously saved GSD file of shift values). When taking parameters from additional headers, the processing window limits (From time, To time, Window) are read automatically from the trace headers stored in the trim gather; otherwise they are set manually.

Input data

Input DataItem

The primary data connection carrying the seismic dataset. Transports the SEG-Y file handle, trace headers, and geometry objects through to the output.

Input SEG-Y data handle

Reference to the SEG-Y file object. Passed through to the output.

Input trace headers

Trace headers for the seismic dataset. Used to match each input trace to its corresponding trim static entry. Passed through unchanged.

Input gather

The NMO-corrected CMP gather to which the trim statics will be applied. Each trace is shifted by its corresponding time correction from the trim data source.

Input stack line

Stack line geometry item, passed through to the output.

Input crooked line

Crooked line geometry item, passed through to the output.

Input bin grid

Bin grid geometry item, passed through to the output.

Input sorted headers

Sorted trace header index, passed through to the output.

Input trim data type { Gather, Trim file }

Selects how the trim static shifts are provided. Gather (default) reads the time shifts from a connected Trim data gather item, typically the output of the Trim statics – Calculate module. Trim file reads the shifts from a previously saved GSD file. Use Trim file when reprocessing data using statics computed in a previous session.

Trim data gather

The output gather from the Trim statics – Calculate module containing the per-trace time-shift values in its trace samples. Connect the Output gather of the Trim statics – Calculate module directly here. Active only when Input trim data type is set to Gather.

Trim file name

Path to a GSD file containing the trim static shifts previously saved to disk. Active only when Input trim data type is set to Trim file.

Parameters

Take params from additional headers

When enabled (default), the From time, To time, and Time window parameters are read from the additional trace headers stored in the trim data gather (written there by Trim statics – Calculate). Disable this option to override those values manually when the headers are not available or when applying a different time window than was used during calculation.

From time

Start time of the application window over which the trim shift is applied, in seconds. Default: 0.1 s. Only editable when Take params from additional headers is disabled.

To time

End time of the application window, in seconds. Default: 3.0 s. Only editable when Take params from additional headers is disabled.

Time window

Length of the cross-correlation window used when reading shift parameters, in seconds. Default: 3.0 s. Only editable when Take params from additional headers is disabled.

Interpolation type { 8-points, Linear }

Algorithm used to resample traces when applying the sub-sample time shifts. Default: 8-points. 8-points sinc interpolation is more accurate and better preserves the frequency content of the shifted traces. Linear interpolation is faster but can introduce mild high-frequency distortion. Use 8-points for final production processing.

Settings

Auto-connection

When enabled, the module automatically connects to adjacent modules in the processing flow.

Bad data values option { Fix, Notify, Continue }

Controls how corrupted (NaN) samples are handled. Fix replaces bad values. Notify stops and reports. Continue proceeds without correction.

Execute on { CPU, GPU }

Selects whether the processing is performed on the CPU or a compatible GPU.

Distributed execution

Options for distributing the computation across multiple nodes in a cluster environment.

Bulk size

Minimum number of gathers in each distributed computation chunk.

Limit number of threads on nodes

Maximum number of CPU threads per distributed node.

Job suffix

Optional text suffix appended to the distributed job name.

Set custom affinity

When enabled, allows specifying a custom CPU core affinity mask for the processing threads.

Affinity

CPU affinity mask. Only active when Set custom affinity is enabled.

Number of threads

Number of CPU threads used for parallel application of trim statics. Set to the number of available physical cores.

Skip

When enabled, this module is bypassed and the input data passes through unchanged.

Output data

Output DataItem

The output data connection carrying the trim-static-corrected dataset.

Output SEG-Y data handle

The SEG-Y file handle passed through from the input.

Output trace headers

The trace headers passed through from the input.

Output gather

The gather with trim statics applied. Each trace has been time-shifted by its corresponding correction value using the selected interpolation method. Connect this to the next step in the processing flow (e.g., stack or further noise attenuation).

Output stack line

Stack line geometry item passed through from the input.

Output crooked line

Crooked line geometry item passed through from the input.

Output bin grid

Bin grid geometry item passed through from the input.

Output sorted headers

Sorted trace header index passed through from the input.

Information

Graphics

Custom actions