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This module reads vibroseis seismic data recorded in SEG-D format as continuous receiver-channel recordings and converts them into conventional triggered gathers for further processing. Unlike standard triggered acquisition where each shot is recorded as a separate file, continuous (or simultaneous) acquisition records all receivers throughout the entire survey day or session. This module uses a time-break file (containing the GPS or POSIX timestamps of each shot firing) and SPS geometry files to locate each shot event within the continuous recording, extract a fixed-length time slice for each source-receiver pair, and cross-correlate the extracted slice against the reference vibroseis sweep signal. The resulting triggered receiver gathers are written to a SEG-Y output file.
This module is particularly suited for simultaneous or blended vibroseis acquisition scenarios. It supports deblending via Gabor-domain filtering to separate overlapping shot contributions from adjacent sources recorded in the same time window. Processing sub-sequences can be applied at two stages: immediately after the initial slicing (before cross-correlation) and after cross-correlation of the extracted gathers.
Custom Action — Read time breaks and SPS files: Use this action to pre-load the geometry (sources and receivers from the SPS file) and the time-break table before running the full conversion. This is useful for validating the geometry match and reviewing the warnings table before committing to a full processing run.
The reference vibroseis sweep signal used for cross-correlation. This gather must contain the pilot sweep waveform recorded during acquisition. The sweep duration and sample interval defined here are used to control the cross-correlation output length. If the sweep duration differs from the configured cross-correlation time, the module will zero-pad the sweep to match the required slice length before cross-correlating.
The list of SEG-D field recording files (.sgd, .segd, .sd, .hd) containing the continuous receiver channel data. Each file represents a recording unit (typically one receiver station or a group of receivers recording continuously). All files in the list will be processed in sequence and the resulting triggered gathers appended to the output SEG-Y file.
The path and filename for the output SEG-Y file (.sgy or .segy) where the triggered, cross-correlated gathers will be saved. If the file already exists, behaviour is controlled by the Rewrite file option — by default, data will be appended to the existing file rather than overwriting it.
The SPS geometry collection containing the source (S-file) and receiver (R-file) point definitions. This geometry is used to match each time-break entry (identified by line number and shot point number) to its corresponding source coordinates, and to assign receiver attributes to each output trace. The geometry must be loaded before processing begins; use the custom action "Read time breaks and SPS files" to validate the geometry before running.
The output record length after cross-correlation, in seconds. Default value is 5 seconds. This controls the length of the triggered gather produced after correlating the receiver slice with the sweep. Set this value to the desired listening time for the final correlated record — typically equal to the swept frequency record length required for subsurface imaging.
The length in seconds of the time window extracted from the continuous recording for each shot event, beginning at the shot firing time indicated by the time-break. Default value is 18 seconds. This should be set to at least the sweep length plus the desired record length (cross-correlation time), to ensure the full correlated response is captured. For blended acquisition, longer slice lengths help capture energy from overlapping shots.
Controls the degree of deblending correction applied when multiple overlapping shots are present in the same time slice. A value of 0 (the default) applies no deblending correction. Higher positive values increase the aggressiveness of the blended-noise suppression. Use this parameter in conjunction with the Deblending group parameters when processing simultaneous-source acquisition data.
When enabled, the output SEG-Y file is overwritten from scratch each time the module is executed. When disabled (default), the output gathers are appended to the existing file. Enable this option when re-running the conversion after parameter changes to avoid mixing results from different processing runs in the same output file.
When enabled, processing halts immediately if an error is encountered while reading or converting any SEG-D file. When disabled (default), errors are logged to the warnings table and processing continues with the remaining files in the list. For large surveys it is generally recommended to leave this option off and review the warnings table after processing completes.
When disabled (default), traces flagged as dead (trace identification code = 2) are excluded from the output SEG-Y file. When enabled, dead traces are retained in the output. Enable this option if downstream processing requires a fixed trace count per gather regardless of live/dead status.
When enabled (default), duplicate shot events that fall within the same time slice are detected and removed, keeping only the primary event. Disable this option only if you specifically need to retain all occurrences of overlapping time-break entries for diagnostic or research purposes.
This group contains all parameters used to read and parse the time-break file that records the absolute timestamps of each shot firing. The time-break file is a text table where each row corresponds to one shot event; the column positions for the shot point number, line number, FFID, and GPS/POSIX time must be specified here.
The path to the time-break text file. Each row in this file represents one shot event and must contain at minimum the shot point number, line number, FFID, and the absolute timestamp of the shot (in GPS or POSIX epoch format). Lines beginning with non-numeric characters are treated as header or comment lines and skipped automatically.
The zero-based column index (starting from 0) in the time-break file that contains the shot point (SP) number. Default value is column 0. Adjust this to match the layout of your time-break file.
The zero-based column index in the time-break file that contains the absolute shot timestamp (as a 64-bit integer GPS or POSIX epoch value). Default value is column 1. The timestamp format (GPS or POSIX) is selected via the Time break type parameter.
The zero-based column index in the time-break file that contains the source line number. Default value is column 10. The line and SP values together uniquely identify a source point in the SPS geometry and are used to match each time-break entry to the correct source coordinates.
The zero-based column index in the time-break file that contains the Field File Identification Number (FFID) for each shot. Default value is column 11. The FFID is used to populate the corresponding trace header field in the output SEG-Y file, enabling cross-referencing with the original field recording.
This parameter group controls the optional Gabor-domain deblending filter. Deblending is used when simultaneous-source (blended) acquisition is detected — that is, when more than one shot event occurs within the slice window, causing the responses from multiple sources to overlap. The Gabor filter separates these contributions in the time-frequency domain before cross-correlation.
Enables the Gabor-domain deblending filter. When disabled (default), no deblending is applied and the raw cross-correlated slice is written to output. Enable this option only when the data was acquired in simultaneous-source mode and multiple shots overlap within a single receiver recording window.
The half-width of the Gaussian taper window used in the Gabor transform, in seconds. Default value is 0.1 s. This controls the time-frequency resolution trade-off of the Gabor decomposition: smaller values give finer time resolution but coarser frequency resolution, while larger values improve frequency resolution at the cost of temporal smearing. Typical values range from 0.05 to 0.2 s depending on the sweep frequency content.
The time step between successive Gabor analysis windows, in seconds. Default value is 0.03 s (30 ms). Smaller step values produce more overlap between adjacent windows, increasing accuracy but also computation time. This should generally be set to no more than half the GaussHalfWindow value for adequate temporal coverage.
The minimum frequency, in Hz, of the output frequency band after Gabor deblending. Default is 0 Hz (no low-cut). Set this to match the lower end of the usable sweep frequency band to suppress low-frequency noise below the sweep range.
The maximum frequency, in Hz, of the output frequency band after Gabor deblending. Default is 90 Hz. Set this to match the upper end of the sweep frequency range. Frequencies above this value are suppressed in the deblended output.
The maximum frequency of the vibroseis sweep signal, in Hz. Default is 90 Hz. This value is used within the Gabor deblending algorithm to define the usable sweep bandwidth boundary and scale the deblending filter. Set this to match the actual upper sweep frequency used during acquisition.
A time-domain amplitude weighting exponent used within the Gabor deblending filter to compensate for time-varying signal amplitude. Default value is 1.0; valid range is 0 to 2. A value of 0 applies no time-dependent weighting. Increase this value to apply stronger compensation for amplitude decay with time, which can improve deblending performance on longer records.
A reference velocity value, in m/s, used within the Gabor deblending algorithm to model the time-frequency signature of interfering shots. Default value is 15000 m/s. This parameter helps the deblending filter distinguish between the desired shot response and the blended noise from nearby simultaneous sources. Set this to a value representative of the near-surface velocity in the survey area.
This group contains advanced SEG-D parsing parameters for handling non-standard or vendor-specific file formats with extra bytes at the beginning or end of trace or file records. These parameters are typically only needed when the SEG-D files have proprietary headers or padding that must be skipped before the actual data can be read correctly.
The number of bytes to skip at the start of each SEG-D file before reading the standard header. Default is 0. Use this parameter when SEG-D files contain a proprietary leader block or non-standard prefix before the standard SEG-D header block.
The number of bytes to skip at the beginning of each trace record (Beginning of Trace). Default is 0. Some acquisition systems prepend a non-standard byte block before each trace header within the SEG-D file. Set this value to the size of that proprietary prefix block.
The number of bytes to skip at the end of each trace record (End of Trace). Default is 0. Use this when acquisition system files contain a trailing suffix block appended after each trace's sample data.
When enabled, applies a manufacturer-specific amplitude scaling factor (MP factor) embedded in the SEG-D trace headers to the output trace amplitudes. Default is disabled. Enable this option if the recording instrument encodes a per-trace gain correction in the MP field of the SEG-D header that should be applied during format conversion.
When enabled, source and receiver coordinates stored in geographic (WGS84 latitude/longitude) format in the SEG-D file are automatically converted to UTM projected coordinates in the output SEG-Y trace headers. Default is disabled. Enable this option when the field recording system writes GPS coordinates in decimal degrees and you require metric UTM coordinates for geometry QC and processing.