Description

Mute by angle range applies an angle-domain mute to pre-stack seismic gathers. For each trace and time sample, the module computes the incidence angle using the Vrms velocity model (or optionally an interval velocity model) and then zeroes traces that fall either inside or outside a specified angle range. This allows selective retention or removal of near-angle, mid-angle, or far-angle portions of a gather, which is essential for AVO analysis, noise suppression at high reflection angles, and conditioning data before pre-stack inversion.

The angle boundaries can be specified as a single pair of constant values (Simple mode) or as a time-varying table (Table mode). The module also outputs the computed angle-versus-time curves and the taper mask for QC in the Graphics panel.

Input data

Input DataItem

The standard seismic data container carrying the pre-stack CIG gathers to be muted.

Input SEG-Y data handle

SEG-Y file handle for reading trace data from disk.

Input trace headers

Trace header vector providing offset and geometry information required for angle calculation.

Input gather

Pre-stack gather (CIG or offset gather) to which the angle mute will be applied.

Input stack line

Stack line geometry for 2D surveys.

Input crooked line

Crooked line geometry for 2D surveys with non-straight acquisition.

Input bin grid

3D bin grid defining inline/crossline coordinates.

Input sorted headers

Pre-sorted trace index used to iterate gathers in the correct order.

Vrms model

Root-mean-square velocity model used to convert offset and two-way time into a reflection angle. Connect the output of a velocity analysis or NMO module. This input drives the angle computation for all formulas except Straight ray.

Parameters

V interval time model

Optional interval velocity model. When connected and the Vrms to angle formula is set to Dix-Snell, the Dix equation is applied to the interval velocity rather than the Vrms model, giving a more accurate angle estimate. Leave disconnected to use only the Vrms model.

Mute type { Inside, Outside }

Controls which part of the gather is zeroed. Default: Inside. Inside zeros traces whose incidence angle falls between From angle and To angle; Outside zeros traces outside that range (i.e., retains only the specified angle band). Use Inside to suppress a noisy angle zone; use Outside to extract a specific angle partial stack.

Surface velocity V0

Near-surface reference velocity (m/s) used in the Snell's law component of the angle calculation. Default: 1800 m/s. Set this to the velocity of the shallowest layer at the source-receiver surface.

Mute data type { Simple, Table }

Selects how the angle range is defined. Default: Simple. Simple uses constant From angle and To angle values applied uniformly across all times; Table uses the Time-angle factors table to define time-varying angle boundaries.

From angle

Minimum angle of the mute window in degrees. Default: 0°. Active when Mute data type is Simple. For example, set to 0° and To angle to 30° to apply an outer mute retaining only the near- and mid-angle range.

To angle

Maximum angle of the mute window in degrees. Default: 45°. Active when Mute data type is Simple. Traces with incidence angles above this value (outside mode) or between From/To angle (inside mode) are zeroed.

Smoothed angles curves

When enabled (default), the angle boundary curves are interpolated spatially between picked control points before applying the mute. Disable for a step-function mute that changes discontinuously from one picked location to the next.

Smoothed values between angles

When enabled (default), amplitude values within the taper zone around the angle boundary are smoothly tapered rather than step-zeroed. Disable to produce a hard edge at the angle boundary without any cosine taper.

Vrms to angle formula { Dix-Snell, Dix-Snell fast, Radius, Straight ray }

Formula used to convert the Vrms model and offset into a reflection angle. Default: Dix-Snell fast. Dix-Snell applies the full Dix inversion followed by Snell's law ray bending at each layer — most accurate but slowest. Dix-Snell fast uses a faster approximation suitable for most surveys. Radius derives angle from the CRE radius parameter. Straight ray uses a simple linear raypath assumption (sin θ = offset / (2 × Vrms × t)), which is fast but less accurate at large angles.

Time-angle factors

Table of time–angle pairs defining time-varying From angle and To angle boundaries. Active when Mute data type is Table. Add rows with the two-way time (s) and corresponding minimum and maximum angles at each control time; the module interpolates between rows.

Draw angle lines step

Angular step (degrees) between constant-angle lines drawn on the gather display in the Graphics panel. Default: 5°. Reduce for finer angular grid lines on the display; increase for a less cluttered view.

Settings

Auto-connection

When enabled, input data items are automatically connected from the nearest upstream module with matching output types.

Bad data values option { Fix, Notify, Continue }

Specifies what to do when NaN or Inf sample values are encountered. Fix replaces bad values with zero; Notify logs a warning and replaces them; Continue passes bad values through without modification.

Calculate difference

When enabled, the module also computes and outputs the difference between the input and the muted gather (i.e., the removed energy). This output is available in the Gather of difference output slot and is useful for QC of what was removed.

Execute on { CPU, GPU }

Selects the processing device. CPU is standard; GPU may accelerate processing on large 3D surveys.

Distributed execution

Configuration for distributed (cluster) execution.

Bulk size

Minimum number of gathers sent per work chunk during distributed execution.

Limit number of threads on nodes

When enabled, restricts CPU thread count per cluster node to the value in Number of threads.

Job suffix

Optional text appended to the distributed job name.

Set custom affinity

When enabled, applies the CPU affinity mask specified in Affinity.

Affinity

CPU affinity mask applied when Set custom affinity is enabled.

Number of threads

Maximum number of CPU threads used during execution.

Skip

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

Output data

Output DataItem

The angle-muted seismic data container. Pass to downstream AVO analysis, pre-stack inversion, or stack modules.

Output SEG-Y data handle

SEG-Y file handle for writing the muted output to disk.

Output trace headers

Trace headers corresponding to the muted output traces.

Output gather

The angle-muted gather for display or further processing.

Output stack line

Stack line geometry passed through from input.

Output crooked line

Crooked line geometry passed through from input.

Output bin grid

Bin grid passed through from input.

Output sorted headers

Sorted trace index passed through from input.

Gather of difference

The removed energy (input minus muted output). Available when Calculate difference is enabled. Use to QC the muted zones — ideally this gather should show only the energy that was intentionally removed and not coherent signal.

Information

Graphics

Custom actions