Usage:
The Apply Linear Moveout step allows you to apply a linear moveout function in either the forward or inverse direction. You specify the moveout velocity. You may also apply a constant static shift to your data. The moveout correction may be applied in a coarse or fine-grained application mode. A coarse grained static shift is applied to the nearest sample. Fine-grained static shifts are applied in the frequency domain by phase shifting your data.
Input Links:
1) Seismic data in any sort order (mandatory).
Output Links:
1) Seismic data in any sort order (mandatory).
Reference:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Constant static shift (ms) Enter a constant static shift in milliseconds.
Correction velocity Enter the constant moveout velocity.
Application Mode: Specify the statics application mode.
Coarse grain If selected, statics shifts are applied to the nearest discrete sample position.
Fine grain If selected, statics shifts are applied as a precise phase shift operator in the Fourier domain.
Do inverse linear moveout application If checked, inverse linear moveout will be applied to your data.
Usage:
The Apply Normal Moveout step allows you to apply normal moveout corrections to your pre-stack data using a single velocity or a set of velocity function cards. You choose between a linear or quadratic interpolation method for interpolating trace sample values back to even sample intervals after applying the moveout. You may also apply a stretch mute to your NMO corrected data. A constant velocity moveout may be accomplished by inputting a correction velocity in the dialog and not connecting any velocity function cards to the step. The NMO process automatically spatially interpolates the velocity over the entire range of CMPs in the line.
In the case of 3D data, the velocity functions are interpolated using a 2-D Delaunay triangulation weighting of evaluation points. Velocity function CMP locations are triangulated, then barycentric coordinates are used to compute weights between velocity functions. The interpolation is done laterally. No allowance is made for structure.
Input Links:
1) Seismic data in any sort order (mandatory).
2) Velocity Function as a card data file (optional).
3) Velocity Function as a seismic file (optional).
Output Links:
1) Seismic data in any sort order (mandatory).
References:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Velocity field definition: Specify velocity field to be used to correct for hyperbolic moveout.
Use velocity field from data file If checked, the velocity field from a card data file will be used.
Use velocity field from seismic file If checked, the velocity field from a seismic file will be used.
Use constant velocity If checked, a constant velocity will be used.
Constant velocity Enter a constant NMO velocity. This constant velocity will be used if a set of velocity function cards is NOT linked to the NMO correction step.
Scale input velocities by (%) Enter the amount by which the input velocities are scaled up or down. A value of 1.0 does not alter the velocity field.
Mute control: Specify the parameters for the stretch mute definition.
Apply mute from data file If checked, a mute will be applied to the NMO corrected data from a data file.
Apply stretch mute If checked, a stretch mute will be applied to the NMO corrected data. Stretch muting removes the stretching of the data due to the NMO correction.
Percentage Enter the stretch mute percentage. The smaller the percent the more severe the mute function.
Taper length Enter the mute taper length in samples. Longer taper lengths result in a smoother transition from the mute zone to the data zone.
Interpolation type selection: Specify the interpolation type (linear or quadratic). The moveout function causes trace data samples to be moved in time to new locations. Since these new time locations of the data sample values are not usually exactly at the sample interval of the data, the data is interpolated to be evenly sampled at the correct sample interval.
Linear Linear interpolation uses the equation of a line (y = mx + b) to interpolate data values between or beyond existing data.
Quadratic Quadratic interpolation uses the equation of a quadratic (y = ax^2 + bx + c) to interpolate data values between or beyond existing data.
Do inverse moveout application If checked, the inverse NMO correction will be applied, instead of the usual forward NMO.
Usage:
The Apply PP Non-hyperbolic Moveout step uses the travel-time equation for transversly isotropic (TI) media described by Alkhalifah and Tsvankin (1997). Non-hyperbolic P-wave moveout may become significant when source-receiver offsets are approximately equal to or greater than the depth of reflection. The resulting deviations from the hyperbolic traveltime equation may be attributed to one or more phenomena: (1) The standard hyperbolic travel-time equation is only a two-term, short-offset approximation of the full travel-time equation for P-wave reflections in layered media; (2) the earth media may be anisotropic. The resulting moveout is a function of the zero-offset time, the source-receiver offset, P-wave short-spread stacking velocity, and h (eta), where eta is an effective anisotropy parameter that measures the ratio of horizontal to vertical P-wave velocity. The Apply PP Non-hyperbolic Moveout step uses the combination of Eta functions and P-wave stacking velocities to correct for non-hyperbolic moveout.
Input Links:
1) Seismic data in any sort order (mandatory).
2) PP Nhmo Eta Function card data file containing eta picks (optional).
3) PP Nhmo Eta Function seismic file containing eta picks (optional).
4) Velocity Function as a card data file (optional).
5) Velocity Function as a seismic file (optional).
Output Links:
1) Seismic data in any sort order (mandatory).
Reference:
Alkhalifah, Tariq, 1997, Velocity analysis using nonhyperbolic moveout in transversely isotropic media: Geophysics, 62, 1839-1854.
Alkhalifah, Tariq, and Tsvankin, Ilya, 1995, Velocity analysis for transversely isotropic media: Geophysics, 60, 1550-1566.
Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Eta field definition: Specify how the Eta field will be defined by your selections and entries to correct for non-hyperbolic moveout.
Use eta functions from data file If checked, the eta functions from a data file will be used.
Use eta field from seismic file If checked, the eta field from a seismic file will be used.
Use constant eta If checked, a constant eta will be used.
Constant eta Enter constant eta value.
Scale input eta values by (%) Enter a percentage to scale input eta values.
P-wave velocity field definition: Specify how the P-wave velocity field will be defined by your selections and entries to correct for non-hyperbolic moveout.
Use velocity functions from data file If checked, the velocity functions from a data file will be used.
Use velocity field from seismic file If checked, the velocity field from a seismic file will be used.
Use constant velocity If checked, a constant velocity will be used.
Constant velocity Enter the short-spread P-wave NMO velocity. This constant velocity will be used if a P-wave stacking velocity function is NOT selected.
Scale input velocities by (%) Enter the amount by which the input velocities are scaled up or down. A value of 1.0 does not alter the velocity field.
Mute control: Specify the parameters for the stretch mute definition.
Apply stretch mute If checked, a stretch mute will be applied to the NMO corrected data. Stretch muting removes the stretching of the data due to the NMO correction.
Percentage Enter the stretch mute percentage. The smaller the percent the more severe the mute function.
Taper length Enter the mute taper length in samples. Longer taper lengths result in a smoother transition from the mute zone to the data zone.
Interpolation type selection: Specify the the interpolation type (linear or quadratic). The moveout function causes trace data samples to be moved in time to new locations. Since these new time locations of the data sample values are not usually exactly at the sample interval of the data, the data is interpolated to be evenly sampled at the correct sample interval.
Linear Linear interpolation uses the equation of a line (y = mx + b) to interpolate data values between or beyond existing data.
Quadratic Quadratic interpolation uses the equation of a quadratic (y = ax^2 + bx + c) to interpolate data values between or beyond existing data.
Do inverse moveout application If checked, the inverse NMO correction will be applied, instead of the usual forward NMO.
Usage:
The Constant Velocity Stacks step generates a file of constant velocity stack traces. You choose the number of velocities with which to stack your data, the first velocity to apply, and the last velocity. You have the option to apply a stretch mute, if you so desire. With the series of constant velocity stack traces, you may page through these stacked panels using Display and interactively pick velocity functions that result in the most coherent stacked sections.
Input Links:
1) Seismic data pre-stack, in CMP sort order (mandatory)
Output Links:
1) Seismic data pre-stack, in CMP sort order (mandatory)
Reference:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Velocity range: Specify the first and last velocities along with the velocity increment to calculate the number of velocities to use in the analysis. A stacked section is calculated for each velocity linearly interpolated between the starting and ending input velocities. The velocity increment will be:
Vinc = (last velocity first velocity)/ (Number of velocities-1).
First velocity Enter the starting velocity for the analysis. This velocity will be used for NMO on the first output stack. {>0.0}
Last velocity Enter the ending velocity for the analysis. This velocity will be used for NMO on the last output stack. {>0.0}
Velocity increment Enter the velocity increment number. This number will be used to linearly interpolate between the first and last velocities.
Line range: Specify the first and last lines along with the line increment to calculate the number of lines to use in the analysis.
First line to analyze Enter the first CMP line number to analyze.
Last line to analyze Enter the last CMP line number to analyze.
Line increment Enter the CMP line increment between lines to analyze.
Location range: Specify the first and last locations along with the location increment to calculate the number of locations to use in the analysis. At each CMP location a range of constant velocity stacks will be generated from the first velocity to the last velocity in increments of Vinc.
First location to analyze Enter the first CMP location number to analyze.
Last location to analyze Enter the last CMP location number to analyze.
Location increment Enter the CMP location increment between groups of CMP locations to analyze.
Locations per analysis Enter the number of CMP locations in each analysis panel.
Mute control: Specify how the mute will be defined.
Apply mute from data file If checked, a mute will be applied to the NMO corrected data.
Apply stretch mute If checked, a stretch mute will be applied to the NMO corrected data. Stretch muting restricts the stretching of the data due to the NMO correction.
Percentage Enter the stretch mute percentage. The smaller the percent the more severe the mute function.
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.
Interpolation type selection Specify the interpolation type (linear or quadratic). The moveout function causes trace data samples to be moved in time to new locations. Since these new time locations of the data sample values are not exactly at the sample interval of the data, the data is interpolated to the correct sample interval.
Linear Linear interpolation uses the equation of a line (y = mx + b) to interpolate data samples between or beyond existing data.
Quadratic Quadratic interpolation uses the equation of a quadratic (y = ax^2 + bx + c) to interpolate data samples between or beyond existing data.
Trace amplitude definition Specify the trace amplitude definition for relative or true amplitude.
Use relative amplitude traces If selected, relative amplitude traces will be summed in the stacking process. Relative amplitude traces are scaled independently of one another.
Use true amplitude traces If selected, uses true amplitude scaled traces in the analysis. True amplitude traces are scaled by one common factor per record.
Exponent for normalization Enter the scaling exponent. Traces are scaled by (fold ** EXP).
Usage:
Create Velocity Field is used to create a velocity-field file from a standard velocity function card, an interval velocity card, or a layer cake model completely from scratch. The constructed model is saved as a SEGY file and can be used either for display or for ray tracing and migration processes.
Input Links:
None.
Auxiliary dataset:
1) Velocity function card data file (optional).
2) Pre-Stack seismic data for geometry (optional).
Output Links:
Seismic file where the velocity model is going to be saved (mandatory).
Reference:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Velocity parameters: Specify parameters related with input velocity
Interpolate from velocity card If checked, connects a standard (RMS) velocity card to the step.
Interpolate from Interval velocity card If checked, connects an interval velocity card to the step.
Use a layer cake velocity model If checked, adds a table allowing the user to built his own layer cake model.
Number of layers specify the number of layers to be considered.
Lateral smoothing parameter Enter a lateral smoothing parameter, or else zero (uses the Damped Least Square Filter processing step for the smoothing).
Depth smoothing parameter specify a depth smoothing parameter, or else zero (uses the damped least square filter for the smoothing).
Scale velocities by factor enter a scaling factor for the input velocities, or else 1.
Velocity model geometry: Specifies the geometry of the output velocity model.
Get geometry from an auxiliary seismic file If selected, get the geometry of the velocity model from an auxiliary seismic file.
Extend velocity field based on Src/Rec positions If checked, extends the velocity model to cover all Src/Rec locations instead of just CMP locations.
Extend extra locations Enter extra locations to extend.
Manually define model geometry If selected, defines the velocity model geometry manually.
First depth sample Enter the first depth sample of the model.
Depth interval Enter the depth interval of the model.
Number of depth samples Enter the last depth sample of the model.
First lateral sample Enter the first lateral sample of the model.
Lateral interval Enter the lateral interval of the model.
Number of lateral samples Enter the last lateral sample of the model.
Headers Updates: Specifies each headers of the output velocity model will be updated.
Use CMP line Update CMP line header word.
Use CMP location Update CMP location header word.
Usage:
The Extract Functions step extracts velocity, Eta or Gamma functions from auxiliary card data files at specific locations as user-defined along an existing seismic data file sorted by CMP.
Input Links:
1) Seismic file in CMP sort order (mandatory).
2) One of the following card data files: Velocity card data file, Eta card data file, Gamma card data file (mandatory).
Output Links:
1) Seismic file with extracted functions (mandatory).
References:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Input seismic field file: Specify type of auxiliary data type from where functions are going to be extracted.
Velocity If selected, an auxiliary velocity card data type will be used.
Eta If selected, an auxiliary Eta card data type will be used.
Gamma If selected, an auxiliary Gamma card data type will be used.
Input velocity field type: Specify type of input velocities in the auxiliary card data file. Only available if Input seismic field file is set to Velocity.
RMS If selected, input velocities are RMS velocities.
Interval If selected, input velocities are Interval velocities.
Average If selected, input velocities are average velocities.
Output auxiliary velocity type: Specify type of output velocities that will be written in output seismic file. Only available if Input seismic field file is set to Velocity.
RMS If selected, input velocities are RMS velocities.
Interval If selected, input velocities are Interval velocities.
Average If selected, input velocities are average velocities.
Function selection: Specify how auxiliary card data files will be sampled.
Regularly spaced locations If selected, auxiliary field will be sampled at regularly spaced locations as user-defined.
All trace locations If selected, auxiliary field will be sampled for all the locations available.
Line Range: Specify the locations to be extract in the Line direction. Only available if Function selection is set to Regularly spaced locations.
First line to extract Enter the value for the first line to be extracted.
Last line to extract Enter the value for the last line to be extracted.
Line increment Enter the value for the increment of the sampling in the line direction.
Location range: Specify the locations to be extract in the Location direction. Only available if Function selection is set to Regularly spaced locations.
First location to extract Enter the value for the first location to be extracted.
Last location to extract Enter the value for the last location to be extracted.
Location increment Enter the value for the increment of the sampling in the location direction.
Vertical point selections: Specify how auxiliary fields are sampled vertically.
Interface kneepoint If selected, auxiliary fields will be sampled at the same vertical locations as the picking.
Average points per functions Enter the desired average number of points per function in the vertical direction.
Regular intervals If selected, auxiliary fields will be sampled vertically at a constant interval
Sampling interval (ms) Enter the sampling interval along the vertical direction.
Usage:
The Interpolate Filed step interpolates velocity, Eta or Gamma fields into a new user-defined geometry
Input Links:
1) Seismic file in CMP sort order (mandatory).
2) One of the following card data files: Velocity card data file, Eta card data file, Gamma card data file (mandatory).
Output Links:
1) Seismic file with extracted functions (mandatory).
References:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Input parameter: Specify type of auxiliary data type from where functions are going to be extracted.
Velocity If selected, an auxiliary velocity card data type will be used.
Eta If selected, an auxiliary Eta card data type will be used.
Gamma If selected, an auxiliary Gamma card data type will be used.
Output velocity field type: Specify type of output velocities in the auxiliary card data file. Only available if Input parameter is set to Velocity.
RMS If selected, input velocities are RMS velocities.
Interval If selected, input velocities are Interval velocities.
Average If selected, input velocities are average velocities.
Output sampling: Specify sampling rate of output seismic file with interpolated field.
As input data If selected, output seismic file will have the same sampling rate as input seismic file.
Specified If selected, output seismic file will have user-defined sampling rate.
Sampling (ms) Enter output sampling rate in milliseconds.
Maximum time (ms) Enter maximum time of output in milliseconds.
Smoohting: Specify vertical smoothing of the input field.
Apply vertical smoothing If checked applies a vertical smoothing to the input field.
Smoothing length (ms) Enter smoothing length in milliseconds.
Vertical interpolation type: Specify type of vertical interpolation of the inut field.
Linear If selected, input field is vertically linearly interpolated.
Quadratic If selected, input field is interpolated following a quadratic function.
Usage:
The Multichannel analysis of surface waves (MASW) step creates multi modal dispersion images, which shows a frequency vs. phase velocity space with pattern of energy accumulation that represents the actual dispersion curve. This implementation is designed to run in single thread or in parallel, giving it the possibility to take full advantage of multiple processors at the same time.
Input Links:
1) Multichannel seismic record.
Output Links:
1) Seismic file where the Dispersion images are going to be stored.
Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Minimum Frequency (Hz) enter minimum frequency to calculate in Hertz.
Maximum Frequency (Hz) enter maximum frequency to calculate in Hertz.
Frequency increment (Hz) enter the frequency increment.
First Velocity (m/s) enter first velocity to calculate in meters per seconds.
Last Velocity (m/s) enter last velocity to calculate in meters per seconds.
Velocity increment (m/s) enter velocity increment in meters per seconds as well.
Coherency factor enter enhanced coherency factor, choose 1 for brute image.
Normalize by amplitude spectrum if checked normalizes amplitude spectrum.
Usage:
The Offset Dependent Linear Moveout step applies a linear moveout correction dependent of the offset and a user-defined constant velocity to the input seismic data. The linear moveout may be applied within a user-defined range of offsets in multiple windows with different offsets.Within each offset window the entire length of each seismic trace is corrected accordingly with selected velocity.
Input Links:
1) Seismic data in any sort order (mandatory).
Output Links:
1) Seismic data in any sort order (mandatory).
Reference:
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Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Do inverse linear moveout If checked, applies an inverse linear moveout as defined below in the window table.
Bulk shit (ms) Enter a value in milliseconds corresponding to a vertical bulk shift of the entire data. If no bulk shift is desired use zero.
Window Sequential number of the offset window where the offset dependent linear moveout will be applied.
Start offset Enter the offset from where the linear moveout will be applied for that specific time window.
Stop offset Enter the last offset where the linear moveout will be applied for that specific time window.
Velocity Enter the velocity to be used in the offset depedent linear moveout for that specific time window.
Add window Add a new offset window.
Delete window Delete the last offset window in the table.
Usage:
Residual Moveout Analysis analyses pre-stack 2D or 3D CMP NMO-corrected gathers for errors in the moveout applied. The required residual moveout is parameterized as a CMP-varying alpha function, using either a standard or a long offset moveout assumption. This parameter is determined fully-sampled using a fast semblance analysis and output as a segy file. A velocity field is not required for the analysis. The output parameter field may then be smoothed as required, using for example, 3D Median with a 5-5-1 filter or similar.
As a final step use Residual Moveout Application with the derived or the smoothed parameter field as auxiliary input to correct the residual moveout errors.
Input Links:
1) CMP records of offset-sorted moveout-applied seismic data (mandatory).
Output Links:
1) CMP-sorted alpha parameter field (mandatory).
Reference:
Castle, R. J. 1994. A theory of normal moveout, Geophysics, Vol 59, No 6, June 1994, pp 983-999.
Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Moveout correction type: Specify if the residual moveout correction should consider standard or long-offsets.
Standard If checked, errors in the standard hyperbolic moveout will be analysed.
Long offsets If checked, errors in the long offset quartic moveout equation will be analysed.
Reference offsets specification: (Used with Long offsets Moveout correction type only)
With long offsets correction there will be an offset where the quartic and quadratic terms in offset balance, known as the Reference offset. The user may select a range of trial reference offsets. The correction parameter will be optimized for each reference offset. The reference offset with best optimization will then be adopted.
To save execution time, the analysis of the best Reference offset could be carried out using a limited number of records, and then this Reference offset used with the entire dataset.
Minimum Ref. offset Enter the smallest offset to use as a reference offset.
Maximum Ref. offset Enter the largest offset to use as a reference offset.
Number of ref. offsets Enter the number of reference offsets to try.
Shift high offsets only If checked, then only offsets greater than the Reference offset will be shifted by the residual moveout. This can be useful when it is only the high offsets that need correction.
Correction limits control: Specify the maximum offset to be used in the analysis and the maximum vertical shift allowed.
Maximum offset Enter the maximum offset to be used to determine the residual moveout to apply.
Maximum shift (ms.) Enter the maximum trace shift in milliseconds that will be allowed at the specified Maximum offset.
Advanced If selected, the semblance control parameters may be modified. This is set as an advanced option as the default parameters are usually fine to use
Scan width Enter the width of the scan for the semblance calculation.
Smoothing width (# scans) Enter the number of scans to be smoothed together.
Max % data stretch Enter the maximum percentage of data stretch allowed.
Semblance width (samps) Enter the semblance width in number of samples.
Smoothing length (samps) Enter the vertical smoothing length in number of samples.
Max initial peaks Enter the maximum initial peaks values.
Output report file If checked, a text report file will be generated giving a few statistics on residual moveout analysis of the specified offset.
Report file: Specify parameters regarding the report file.
Report Offset Enter the offset for which statistics will be generated in the report file.
File Browse Click to specify a Report file location.
Append to existing file If checked, the statistics for the specified offset will be tagged on to the end of any text already in the specified file. Otherwise, the contents of the file specified, if already existing, will be overwritten by the current text output.
Usage:
Residual Moveout Application applies residual moveout to normal moveout-corrected gathers to correct for moveout errors due to use of incorrect velocities or the use of standard hyperbolic moveout when long offset moveout would have been better used.
To perform residual moveout, the Residual Moveout Functions file generated by Residual Moveout Analysis is required as auxiliary input. This fully-sampled parameter file with one time trace per CMP should be inspected and smoothed if necessary before used as auxiliary file to Residual Moveout Application.
Input Links:
1) CMP records of offset-sorted moveout-applied seismic data (mandatory).
2) Auxiliary Residual Moveout Functions file as generated by Residual Moveout Analysis (mandatory).
Output Links:
1) CMP-sorted alpha parameter field (mandatory).
Reference:
Castle, R. J. 1994. A theory of normal moveout, Geophysics, Vol 59, No 6, June 1994, pp 983-999.
Example Flowchart:
Residual Moveout Correction:
Residual Moveout Correction and Stack:
Step Parameter Dialog:
Parameter Description:
No parameters All parameterization is specified in the prior analysis step Residual Moveout Analysis.
Usage:
The Velocity Semblance step creates velocity semblance displays for the input CMP records. Stacking velocities may be picked interactively from this semblance display in SeisViewer. For semblance display generation, you designate the velocity range for semblance calculation by choosing the number of velocities, the starting velocity for this range, and the velocity increment. You may generate only one CMP semblance display for each input CMP gather. You may also control the time gate length around hyperbolic velocity paths for CMP summing in the semblance calculation using the Semblance length input parameter. Finally, the output semblance display may be windowed, and a stretch mute may be applied if so desired.
Input Links:
1) Seismic data in CMP sort order (mandatory).
Output Links:
1) Seismic File (mandatory).
Reference:
Taner, M. and Kohler, 1969, Velocity spectra digital computer derivation and applications of velocity functions, Geophysics, v. 34, no. 6, p. 859ff.
Example Flowchart:
Step Parameter Dialog:
Parameter Description:
Velocity range: Specify the velocity range where the semblance will be computed.
First velocity Enter the first velocity to scan.
Last velocity Enter the first velocity to scan.
Velocity increment Enter the value by which the velocity is incremented.
Semblance window: Specify the smoothing length of the semblance window.
Semblance length (ms) Enter the length of the semblance calculation window in milliseconds.
Interpolation type selection: Specify the interpolation type (linear or quadratic). The moveout function causes trace data samples to be moved in time to new locations. Since these new time locations of the data sample values are not exactly at the sample interval of the data, the data is interpolated to even sampling at the correct interval.
Linear Linear interpolation uses the equation of a line (y = mx + b) to interpolate data values between or beyond existing data.
Quadratic Quadratic interpolation uses the equation of a quadratic (y = ax^2 + bx + c) to interpolate data values between or beyond existing data.
Mute Control: Specify the stretch mute control parameters.
Apply mute from data file If checked, a stretch mute card data will be added to the flow and applied to the NMO corrected data
Apply stretch mute If checked ,apply strectch mute as defined below.
Percentage Enter the percent stretch mute. The smaller the percent the more severe the mute function.
Taper length Enter the mute tape length in samples. Longer taper lengths result in a smoother transition from the mute zone to the data zone.
Trace Amplitude Definition: Specify amplitude summing selection.
Use relative amplitude traces Selects the use of relative amplitude scaled traces in the analysis. Relative amplitude traces are scaled independently of one another.
Use true amplitude traces Absolute amplitude traces will be summed in the stacking process. True amplitude traces are scaled by one common factor per record.
Use RMS balanced traces Amplitude traces will be balanced using RMS.