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The Signal-noise ratio module estimates the signal-to-noise ratio (S/N) for every trace in a seismic gather. For each trace, the module builds a coherent model trace by selecting a window of neighboring traces, aligning them to the current trace via cross-correlation, and stacking them. The S/N value is then computed as the ratio of the maximum residual amplitude (the difference between the current trace and the model trace) to the maximum amplitude of the current trace itself. A low S/N value indicates that the trace is well-predicted by its neighbors and therefore contains predominantly coherent signal, while a high value indicates a noisy or incoherent trace.
Use this module as a quality control tool to identify noisy traces before further processing, or to assess the overall data quality of a shot gather, CMP gather, or any other gather type. The results are displayed both as a per-trace graph (S/N ratio versus trace number) and as a table that can be exported for further analysis.
The seismic gather to be analyzed. This can be any gather type: shot gather, CMP gather, receiver gather, or offset gather. All traces in the gather are processed sequentially, and a noise ratio value is computed for each one. The gather is not modified — this module is a read-only analysis tool.
The start time (in seconds) of the analysis window. The S/N calculation is performed only within the portion of each trace between Time start and Time end. Set this to the top of the zone of interest to exclude surface noise or shallow high-amplitude events that could skew the result. The default value of -0.001 s is a sentinel value meaning the analysis starts from the very beginning of the trace record.
The end time (in seconds) of the analysis window. Only the portion of each trace up to this time is used for the S/N computation. Set this to the base of the target zone to avoid including deep low-energy reflections that may artificially inflate the noise estimate. The default value of -0.001 s is a sentinel value meaning the analysis extends to the end of the trace record. Both Time start and Time end markers are displayed as horizontal lines overlaid on the input gather in the interactive view, so you can visually verify the selected window before running the analysis.
The number of neighboring traces (centered on the current trace) used to construct the coherent model trace for each S/N estimate. A larger window includes more traces in the local stack, which produces a more stable model but may blend signal from geologically different areas if the gather contains lateral variation. A smaller window is more sensitive to local trace-by-trace differences but may yield a noisier S/N estimate. The default value is 11 traces, which is a practical starting point for most CMP and shot gathers. For very sparse or laterally variable gathers, try reducing this value to 5 or 7 traces.
The maximum time shift (in seconds) allowed when cross-correlating neighboring traces before stacking them into the model trace. This parameter compensates for moveout and other time delays between adjacent traces, ensuring that coherent reflections are properly aligned before the model stack is formed. If the shift is too small, the model trace may be poorly aligned with actual reflections and the S/N estimate will be unreliable. If too large, unrelated events from different traces may be incorrectly aligned. The default value is 0.020 s (20 ms), which is appropriate for gathers with moderate residual moveout. Increase this value for gathers with large offsets or uncorrected moveout, and decrease it for near-offset or well-corrected gathers.