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This module is deprecated and is no longer recommended for new projects.
PSPCI PostSDM performs post-stack depth migration of a stacked seismic section using the Phase Shift Plus Correction of Imaging (PSPCI) algorithm. It accepts a stacked gather and an interval velocity model and produces a migrated image in either the time or depth domain. The algorithm applies a phase-shift migration operator in the frequency-wavenumber domain, using the interval velocity field to account for lateral velocity variations, and optionally applies an anti-aliasing filter and elevation-based datum correction. The module supports both 2D and 3D datasets; for 3D, the number of inlines and crosslines and their spatial sampling must be configured explicitly.
The input stacked seismic gather to be migrated. The stack must have the same number of traces as the product of the configured number of inlines and crosslines for 3D datasets. For 2D data, supply the stacked section directly.
The interval velocity model used to drive the migration phase-shift operator. The velocity gather must have the same number of traces as the input stack and, when migrating in the time domain, the same sample rate. Connect this to the output of a Dix conversion, tomography, or velocity model builder.
Selects the output domain for the migrated image. The default is Time. Set to Depth to produce a depth-migrated image with the vertical axis in metres. When set to Time, the migrated output is returned in the time domain (two-way time in milliseconds).
When enabled (default: true), applies a migration mute to the output image to suppress operator artefacts and wrap-around energy in the shallow part of the section. Disable this option only if you need to examine the full, un-muted output for diagnostic purposes.
The maximum frequency (in Hz) processed by the migration operator at shallow depths (the top of the section). The default is 40 Hz. This parameter limits the frequency bandwidth of the operator at the shallowest part of the section, where higher frequencies may be aliased or noisy. It must be greater than Maximal frequency at the bottom.
The maximum frequency (in Hz) processed by the migration operator at depth (the bottom of the section). The default is 35 Hz. Deep reflectors naturally have lower dominant frequency due to attenuation; restricting the high-frequency content here avoids migrating noise at depth. If this value is set equal to or greater than Maximal frequency up shallow, it will be automatically reduced to one less than that value.
The maximum number of distinct velocity values used to construct the phase-shift operator at each depth step. The default is 5, with a range of 1 to 60. The PSPCI algorithm handles lateral velocity variations by decomposing the velocity field into a limited set of reference velocities at each depth; higher values improve the accuracy of the operator for strongly laterally varying velocity models but increase computation time.
When enabled (default: true), applies an anti-aliasing taper to the migration operator to suppress spatial aliasing artefacts in steeply dipping events. Disable this option only for testing or when processing data with very gentle dips and fine spatial sampling.
When enabled (default: true), applies an elevation datum correction to the migration, using the Replacement velocity and Datum values to account for surface topography. Disable this option for flat-datum or marine data where no elevation correction is needed.
The constant replacement velocity (in m/s) used to fill the zone between the recording datum and the floating datum during elevation correction. The default is 1500 m/s. Use a value appropriate to the near-surface lithology of the survey area — typically the velocity of the replacement fill used during static corrections.
The reference datum elevation (in metres) used for the elevation correction. Set this to the same datum elevation used during static corrections for the survey. This parameter is only relevant when Elevation is enabled.
The number of inline traces in the 3D input volume. The default is 1 (appropriate for 2D data). For 3D migration, set this to the total number of inline positions in the input stack gather. The product of Number of inlines and Number of crosslines must equal the trace count of the input stack.
The number of crossline traces in the 3D input volume. The default is 100. For 2D data, set this to the number of traces in the section and keep Number of inlines at 1.
The spatial sampling interval between adjacent inline positions in metres. The default is 25 m. This value must match the actual inline bin spacing of the survey; incorrect values will cause the migration operator to apply the wrong dip moveout correction.
The spatial sampling interval between adjacent crossline positions in metres. The default is 25 m. For 2D data this corresponds to the CMP spacing along the line. The value must be positive.