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Note: This module is deprecated. It is retained for compatibility with existing workflows.
The Simple Modelling by Trace Headers module generates synthetic pre-stack seismic data directly from an existing trace header geometry. For each trace in the input trace vector, the module computes hyperbolic travel times for a series of horizontal reflection layers and for diffraction points interpolated from the geometry, convolves the resulting reflectivity spike series with a configurable wavelet, and writes the output traces to a SEG-Y file. This produces a synthetic shot gather dataset that has the same acquisition geometry as the real data, which can be used for geometry QC, algorithm testing, or initial model validation.
The module assumes a homogeneous velocity model with a single constant velocity V0 for all layers. It also simulates diffraction energy from four interpolated diffractor positions derived from the geometry, allowing basic diffraction patterns to appear in the synthetic output. If an input wavelet gather is connected, that wavelet is used for convolution; otherwise the wavelet shape and frequency are controlled by the WaveParams parameters.
The trace header collection that provides the acquisition geometry for the synthetic model. The module reads the source and receiver XY coordinates, elevation values, and picket numbers from these headers for each trace. The output synthetic dataset will have one trace for each trace present in this vector, with the same geometry layout. Connect the output of a geometry loading or geometry application module here.
An optional input gather containing a seismic wavelet to be convolved with the reflectivity series. When connected, this wavelet overrides the analytical wavelet defined by the WaveParams parameters. Leave this input unconnected to use the analytically generated wavelet from the WaveParams group.
The constant P-wave velocity used to compute hyperbolic reflection travel times for all layers in the synthetic model, in m/s. All reflectors are modelled as horizontal and located at depths derived from the two-way time grid using this single velocity. Set this to the average interval velocity representative of the depth range you wish to model.
Default: 2000 m/s.
The total number of time samples in each output synthetic trace. Together with Sample ratio, this defines the total record length of each trace (Total length = Number of samples × Sample ratio). Set this so that the synthetic record length covers the maximum expected two-way travel time for the deepest reflector you wish to model.
Default: 1000.
The temporal sampling interval of the output synthetic traces, in seconds. Set this to match the sample interval of your field data so that the synthetic output is directly comparable to the real data (e.g. 0.002 s for 2 ms data).
Default: 0.004 s (4 ms).
When enabled (default), the elevation (Z coordinate) of all sources and receivers is set to zero before computing travel times, effectively assuming a flat acquisition surface. This simplifies the modelling and avoids introducing topographic time shifts into the synthetic data. Disable this option only if the acquisition elevation variation is significant and you want the synthetic data to reflect the actual surface geometry.
Default: Enabled.
The path and file name of the output SEG-Y file to which the synthetic traces will be written. Specify a full path in the project directory or use the file browser to select the destination. The module writes all synthetic traces sequentially into this single file with trace headers matching the input geometry.
This group controls the analytical wavelet used for convolution when no external wavelet gather is connected to the Input wavelet input. Three sub-parameters are available:
ImpulseType — the mathematical shape of the wavelet. Available options include Ricker1, Ricker2, AKB, Berlage, Gaussian, GaussianDeriv, MinPhase, Klauder, Ormsby, Spike, Zero, and Unit. Ricker1 (a symmetric zero-phase Ricker wavelet) is the most common choice for synthetic modelling.
Frequency — the dominant (peak) frequency of the wavelet in Hz. Set this to match the dominant frequency of the real data at the target depth to make the synthetic data directly comparable.
WaveLen — the total length of the wavelet window in seconds. This should be long enough to contain the full wavelet shape without truncation; typically 3–5 times the dominant period (1/Frequency) is sufficient.