This section documents the processing steps available in the Mutes category.
The types of mutes currently available are:
Usage:
The Apply Early Mute step allows you to apply mute definitions to your data from different sources. You may choose to interpolate mute functions for the records between the picked mute records or to just mute the records associated with the picked mutes. Mute function may be defined by auxiliary mute card data file or using a constant velocity linearly versus offset. You have a choice of applying a Hanning, Hamming, or Blackman type of mute taper, or none at all. You may also specify in samples the length of the mute taper and scale the input offsets by a value. Early mutes may be interactively defined using first the Display menu to select the file, then the Picking menu to select the type of mute.
Input Links:
1) Seismic data in any sort order (mandatory).
2) Early Mute Function card (optional).
Output Links:
1) Seismic data in any sort order (mandatory).
Reference:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Mute definition: Specify the parameterization for the mute function.
Velocity — If selected, the mute function is defined linearly with the offset using a constant velocity.
Velocity — Enter the constant velocity value to be used to define the mute functions.
Early mute file — If selected, an auxiliary Early Mute auxiliary card data file is used to define the mute definition.
First arrivals files — If selected, an auxiliary First Break Times auxiliary card data file is used to define the mute function.
VSP first arrivals files — If selected, an auxiliary VSP First Arrival Time Picks auxiliary card data file is used to define the mute function.
Samples shift at zero offset — Enter the number of samples to be shifted at the zero-offset when applying the mute.
Samples shift at maximum offset — Enter the number of samples to be shifted at the maximum offset when applying the mute.
Apply value from header — If selected, the mute function is defined by values stored in a specific trace header locations.
Mute header — Select the location of the trace header with the mute value.
Mute Taper Type: Specify the type of taper to use when applying the mute function.
Hanning — Is selected, a Hanning taper is specified by the equation: x(n) = 0.5 - 0.5 * cos (2*pi*n/N).
Hamming — Is selected, a Hamming taper is specified by the equation: x(n) = 0.54 - 0.46 * cos (2*pi*n/N).
Blackman — Is selected, a Blackman taper is specified by the equation: x(n) = 0.42 - 0.5 * cos (2*pi*n/N)+ 0.08 * cos (4*pi*n/N).
No taper — Is selected, no taper will be applied to the mute. This may result in problems in later processing steps due to Gibbs effect.
Mute taper length (samples) — Enter the mute taper length in samples. Longer taper lengths result in a smoother transition from the mute zone to the data zone.
Mute record interpolation: Speciy interpolation parameters of the mute function.
Mute interpolation between input records — If checked, the early mutes will be interpolated between the control points where picks were made.
Field File order — If selected, interpolation between input records is done in the field file order.
Receiver order — If selected, interpolation between input records is done in the receiver order.
Source order — If selected, interpolation between input records is done in the source order.
CMP order — If selected, interpolation between input records is done in the CMP order.
Scale input offsets by — Enter a value to scale the input offsets.
Usage:
The Apply Surgical Mute step allows you to apply mute definitions to your data from the attached Surgical Mute Function auxiliary card data file. You may choose to interpolate mute functions for the records between the picked mute records or to just mute the records associated with the picked mutes. You have a choice of applying a Hanning, Hamming, or Blackman type of mute taper, or none at all. You may also specify in samples the length of the mute taper and scale the input offsets by a value. Surgical mutes may be interactively defined using first the Display menu to select the file, then the Picking menu to select the type of mute.
Input Links:
1) Seismic data in any sort order (mandatory).
2) Surgical Mute Function card (mandatory).
Output Links:
1) Seismic data in any sort order (mandatory).
Reference:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Mute taper type: Specify the type of taper to use when applying the mute function.
Hanning — A Hanning taper is specified by the equation : x(n) = 0.5 - 0.5 * cos (2*pi*n/N).
Hamming — A Hamming taper is specified by the equation : x(n) = 0.54 - 0.46 * cos (2*pi*n/N).
Blackman — A Blackman taper is specified by the equation : x(n) = 0.42 - 0.5 * cos (2*pi*n/N)+ 0.08 * cos (4*pi*n/N).
No taper — No taper will be applied to the mute. This may result in problems in later processing steps due to Gibbs effect.
Mute taper length (samples) — Enter the mute taper length in samples. Longer taper lengths result in a smoother transition from the mute zone to the data zone.
Scale input offsets by — Enter a value to scale the input offsets.
Mute Interpolation — If checked, the surgical mutes will be interpolated between the control points where picks were made.
Usage:
The Apply Tail Mute step allows you to apply mute definitions to your data from the attached Tail Mute Function auxiliary card data file or using a linear function of constant velocity versus offset. You may choose to interpolate mute functions for the records between the picked mute records or to just mute the records associated with the picked mutes. You have a choice of applying a Hanning, Hamming, or Blackman type of mute taper, or none at all. You may also specify in samples the length of the mute taper and scale the input offsets by a value. Tail mutes may be interactively defined using first the Display menu to select the file, then the Picking menu to select the type of mute.
Input Links:
1) Seismic data in any sort order (mandatory).
2) Surgical Mute Function card (optional).
Output Links:
1) Seismic data in any sort order (mandatory).
Reference:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Mute taper type: Specify the type of taper to use when applying the mute function.
Hanning — A Hanning taper is specified by the equation : x(n) = 0.5 - 0.5 * cos (2*pi*n/N).
Hamming — A Hamming taper is specified by the equation : x(n) = 0.54 - 0.46 * cos (2*pi*n/N).
Blackman — A Blackman taper is specified by the equation : x(n) = 0.42 - 0.5 * cos (2*pi*n/N)+ 0.08 * cos (4*pi*n/N).
No taper — No taper will be applied to the mute. This may result in problems in later processing steps due to Gibbs effect.
Mute taper length (samples) — Enter the mute taper length in samples. Longer taper lengths result in a smoother transition from the mute zone to the data zone.
Scale input offsets by — Enter a value to scale the input offsets.
Mute Interpolation — If checked, the surgical mutes will be interpolated between the control points where picks were made.
Velocity — If selected, the mute function is defined linearly with the offset using a constant velocity.
Velocity — Enter the constant velocity value to be used to define the mute functions.
Usage: The Build Mask Model step allows you to build an output seismic file with zeros and ones that can be used to set to null specific samples or as auxiliary file for the Simultaneous Iterative Refraction Tomography (SIRT) analysis. The geometry of the output file may be defined manually of by an auxiliary seismic file. The masked region may be defined using a surgical mute card file.
Input Links:
1) Seismic data in any sort order (mandatory).
2) Seismic data in any sort order to define geometry (optional).
3) Surgical Mute Function card (optional).
Output Links:
1) Seismic data in any sort order (mandatory).
Reference:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Define geometry: Specify parameters related with the geometry of the output seismic file.
Define geometry manually — If selected, the output seismic file with the mask has a geometry as defined manually with the parameters below.
Number of lines — Enter the number of line.
Number of locations — Enter the number of locations.