Angle Stacks

Description Create one or more angle stacks from gathers using a velocity volume.
Module(s) Explorationist, Gather Attributes
Requirements Gathers, Velocity Model
Related Mute Gathers, Stacking
Works with Gathers

The Angle Stacks process creates angle stacks from a gather volume using a velocity model. Different muting and stacking options are available.

Create Angle Stacks process

Create angle stacks process
  1. In the Control Panel, open the Process tab.
  2. Click the blue + icon and select New Process.
  3. Search and double-click Angle Stacks.
  4. Type a name for the process and click OK.

Define settings for Angle Stacks

Define settings for angle stacks
  1. Select the Gather and Velocity Volume.
    • If you provide offset gathers, a velocity model is required to calculate the paths of the angle mutes.
  2. At Velocity Type, select the type of velocity used in the process.
  3. Select the Velocity Units.
  4. At Velocity smoothing length (ms), additional smoothing can be applied to the velocities before use (for more information regarding this parameter, see Creating an Angle Mute).
  5. Surface horizon: Specify a horizon from which the mute can begin. This option is currently only supported for interval velocities in depth. For application in the depth domain, the angle mute will start at the horizon depth, using only the velocities below the surface horizon. If applied in the time domain, the surface horizon will be treated as time = 0.
  6. (Optional) specify a Inner Angle Protection and/or Outer Angle Protection to apply offset-domain mutes.
    • Inner Angle Protection: Offsets above this value will not be muted by the inner angle mute
    • Outer Angle Protection: Offsets below this value will not be muted by the outer angle mute
  7. Set the mute Ramp Distance to taper the mute.
  8. Stacking options: choose a stacking mode and define the positive and negative offset ranges (see Stacking for more information).
    • Standard: (Σ x) / n
    • Root N: (Σ x) / √ n
    • Square of sum of square roots: Σ (√ x)2 / n      
    • Offset: (Σ (x * offset(x))      
    • Blackman: Same as offset, with the input values being weighted by a Blackman window rather than the offset, such that the near and far offset values are damped relative to the mid-offsets.      
    • Hamming: As for Blackman mode, with a Hamming windowing function used in place of the Blackman windowing function.
    • Median/mean: Returns the mean of the values within 'percent to keep' of the median where, for example, 70% will eliminate the lowest 15% and highest 15% percentiles from the mean calculation.
  9. For each angle stack to generate:
    • Click the blue "+" button
    • Name the stack: e.g. Near, Mid and Far.
    • Enter the Inner stacking angle  (between 0 and 90 degrees)
    • Enter the Outer stacking angle (between 0 and 90 degrees)
    • Click the red X to remove a stack
    • One angle stack is created in the Volume tab for each row