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Note: This module is deprecated. It is retained for backward compatibility with existing workflows. For new projects, use the current residual statics modules available in the Statics group.
CalculateStaticShifts computes per-trace residual static shifts for a prestack gather using an iterative cross-correlation method. For each gather, a model (pilot) trace is formed by stacking all traces together. Each individual trace is then cross-correlated against this model trace to determine the time shift that maximizes the correlation. The computed shifts are applied to align the traces, after which a new model trace is formed from the aligned gather and the process is repeated for three iterations. The final per-trace static shifts are stored in a Static Correction output item and the corrected gather is passed downstream.
This module is suitable for computing trim (residual) statics on common-midpoint or other prestack gathers where trace-to-trace time misalignments need to be corrected after normal moveout. The resulting static corrections can be applied separately using the Apply Static Shifts module.
The prestack seismic gather on which residual static shifts are to be calculated. Traces should already have NMO correction applied so that the residual misalignments to be corrected are small (typically a few milliseconds). The gather is processed trace by trace: each trace is cross-correlated against a pilot trace derived from the stack of all gather traces.
When enabled, the amplitude envelope (analytic signal via Hilbert transform) of each trace is computed before the cross-correlation is performed. Using the envelope removes sensitivity to polarity reversals and phase variations between traces, which can improve the stability of the static shift estimates on data with mixed polarities or strong phase distortion. Default: enabled. Disable this option if the data has consistent polarity and you prefer to cross-correlate the raw waveforms directly.
The maximum allowable residual static shift, in milliseconds. The cross-correlation search for the time shift that maximizes alignment is restricted to the range from negative MaxShift to positive MaxShift. This prevents unrealistically large shifts caused by noise or cycle-skipping. Setting this value to 0 disables the constraint and allows the search to span the full trace length. Default: 0 (disabled). Valid range: 0 to 1000 ms. For typical trim static applications, set this to a value slightly larger than the expected maximum residual (e.g., 20–50 ms) to prevent cycle-skipping artifacts.
Controls the interpolation method used when applying the computed fractional-sample static shifts to the traces. When enabled, a faster but less accurate interpolation algorithm is used, which reduces computation time at the cost of slightly lower precision in the applied correction. When disabled, a higher-quality interpolation is applied. Default: disabled. Enable this option for large datasets where processing speed is a priority and sub-sample accuracy is not critical.
A data item containing the computed per-trace residual static shift values for all processed gathers. These values are accumulated across all input gathers and can be passed to a downstream Apply Static Shifts module to apply the corrections independently, or used for quality control and analysis of the computed statics field.
The input gather with the computed residual static shifts applied. Traces in this output gather are time-shifted by the amounts determined during the cross-correlation iterations, resulting in improved trace-to-trace alignment. This corrected gather is suitable for stacking or further processing.