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<< Click to Display Table of Contents >> Navigation: Diffraction > Imaging - Diffraction imaging 2D/3D |
The Imaging - Diffraction imaging 2D/3D module is an interactive visualization and analysis tool for diffraction-based imaging results. It reads pre-computed diffraction semblance stacks produced by the Engine - Diffraction imaging 2D/3D module and displays them as inline and crossline seismic sections. Users can navigate the bin grid interactively, cycle through azimuth panels, and inspect the azimuth-semblance diagram to identify the dominant diffraction direction at any location.
The module is designed for QC and interpretation of diffraction imaging results. It does not reprocess the data; all computation is done by the Engine module, which writes its output to a storage file (.kdb). This Imaging module reads that storage file and provides a fully interactive map-based interface: click any bin on the map to instantly update the inline and crossline images for that location. Scroll the mouse wheel to step through azimuth panels while viewing the semblance images. When satisfied with the results, use the Export full cube custom action to write all azimuth stacks to disk as individual .gsd volume files for further interpretation.
The path to the diffraction imaging storage database (.kdb file) produced by the Engine - Diffraction imaging 2D/3D module. This file contains the full multi-azimuth semblance stack computed over the survey grid. Specify whether the survey is 2D or 3D using the Storage type selector above this field. The module will read bin geometry, azimuth count, sample rate, and all computed stacks from this file. Bins that have not yet been computed by the Engine module are shown as uncalculated on the map and will appear blank in the displays.
An optional trace header collection defining an arbitrary line path through the grid. When supplied, the module displays the diffraction semblance image along that irregular line instead of along a standard inline or crossline. This is useful for QC along crooked 2D lines or for extracting images along user-defined interpretation paths. If no arbitrary line is connected, the module operates in standard inline/crossline mode.
Selects which azimuth panel to display in the inline and crossline seismic image windows. Azimuth panels are numbered starting from 0, with the total number of panels defined when the Engine module computed the stacks. For example, if the Engine was run with 6 azimuths (0°, 30°, 60°, 90°, 120°, 150°), valid indices are 0 through 5. Changing this value immediately refreshes the seismic displays to show the selected azimuth. You can also step through azimuths interactively by scrolling the mouse wheel while the seismic display is active.
Controls the trace ordering used when writing the full cube export files. When enabled, output volumes are written in crossline-major order (traces sorted by crossline, then by inline). When disabled (default), traces are written in inline-major order. Choose the order that matches the expected input format of your downstream interpretation software. Default: disabled (inline order).
This parameter group controls how the diffraction semblance images are displayed. The group contains the following sub-parameters:
Defines the half-length of the time window (in seconds) used when computing the local maximum semblance for the azimuth diagram after clicking a point on the seismic display. When you click a location on the inline or crossline semblance image, the module searches within a window of ±this value in time around the clicked time sample to find the peak semblance and determine the dominant azimuth. Smaller windows focus on a narrower time range around the picked event; larger windows average over a broader zone. Default: 0.020 s (20 ms).
Defines the half-width of the trace search window (in number of traces) used when computing the local maximum semblance for the azimuth diagram after clicking on the seismic display. The module searches ±this many traces laterally around the clicked trace position to find the peak semblance. Increase this value on sparse or noisy data where the diffraction peak may be laterally offset from the expected bin. Default: 10 traces.
When enabled, applies a time shift to the displayed semblance images to correct for topographic elevation differences, referencing the display to the datum elevation specified in the Datum parameter below. Enable this when the survey has significant surface topography and you want to correlate diffraction events with a flat reference level. Requires both the Datum elevation and the Velocity to be set correctly. Default: disabled.
The reference elevation (in meters) to which diffraction images are shifted when ShiftToDatum is enabled. Set this to the project datum elevation — typically the mean surface elevation or a project-specific flat reference level. This parameter has no effect when ShiftToDatum is disabled.
The near-surface seismic velocity (in m/s) used to convert the elevation difference between the surface topography and the datum into a two-way time shift. This value is used only when ShiftToDatum is enabled. Set this to the average weathering-layer or near-surface replacement velocity appropriate for the survey area. Default: 2000 m/s.
This parameter group defines the currently selected bin by its inline and crossline number. Changing these values programmatically navigates the display to that bin, equivalent to clicking on that location on the map. The group contains the following sub-parameters:
The inline number of the currently selected bin. Setting this value (together with the Crossline parameter) moves the display to the specified bin location, updating the inline and crossline semblance images and the azimuth diagram for that position. This is useful for navigating to a specific known location without clicking on the map.
The crossline number of the currently selected bin. Works together with the Inline parameter to navigate to a specific bin by its grid coordinates. Setting this value triggers an immediate update of all displayed images for the new location.
This parameter group enables additional display panels alongside the primary semblance images. When enabled, the corresponding data panels appear in the inline and crossline display windows, allowing side-by-side QC of the diffraction semblance against the raw stacked data and the fold distribution. The group contains the following sub-parameters:
When enabled, loads and displays the stacked field amplitude data alongside the semblance image for each azimuth. This allows you to compare the raw stacked energy (field gather image) with the diffraction semblance to verify that high-semblance regions correspond to genuine diffraction energy rather than coherent noise. Default: disabled.
When enabled, loads and displays the trace fold count alongside the semblance image for each azimuth. The fold image shows how many traces contributed to each sample position in the stack. Use this to identify low-fold areas where the semblance values may be unreliable due to insufficient coverage. Default: disabled.
This parameter group controls the full-volume export of all azimuth diffraction stacks to disk. When the Export full cube custom action is triggered, one set of three files is written per azimuth: a semblance stack file, a field stack file, and a fold file. The files are named automatically using the base name specified below, with suffixes indicating the azimuth index and data type. The group contains the following sub-parameters:
The base file path and name for the exported volume files (.gsd format). The module appends azimuth index and data-type suffixes automatically. For example, if you enter D:\results\diffr, the output will include files such as diffr_0.gsd (semblance, azimuth 0), diffr_Field_0.gsd (field stack, azimuth 0), diffr_Fold_0.gsd (fold, azimuth 0), and so on for each azimuth. Ensure the target directory exists and has sufficient disk space before triggering the export.
Controls how bins that were not computed by the Engine module are handled in the exported cube. When enabled, uncalculated bins are written as zero-filled traces, preserving the full regular grid geometry in the output file. When disabled (default), uncalculated bins are skipped, resulting in a sparse output file. Enable this option if your interpretation software requires a complete regular grid without missing traces. Default: disabled.