Description

This module is the first, data-analysis stage of a surface-consistent amplitude correction workflow. It scans the entire dataset, optionally applies a 4D mute to exclude unwanted energy (e.g. water-bottom multiples or noise picked on a separate horizon), and measures the RMS amplitude level of every trace. The per-trace amplitude levels are stored (in log domain, keyed by record/shot index) together with the overall average amplitude level of the survey, producing an amplitude item that the following "SC Amplitude correction" edit and apply modules use to decompose and correct amplitude variations by source, receiver and offset.

Input data

Input traces

The seismic data (SEG-Y volume and its trace selection) that the amplitude statistics are computed from. This is the full dataset over which surface-consistent amplitude behaviour will be estimated, so it should cover the area/lines you intend to correct.

4D mute picking

An optional mute picking object (as used elsewhere in 4D/time-lapse workflows) that defines a time boundary per trace. Samples excluded by this mute are left out of the amplitude analysis, which keeps the estimate focused on the signal of interest and away from muted zones such as direct arrivals, water-bottom multiples, or geometry-related gaps.

Parameters

Read Traces per chunk

Number of traces read and analyzed together as one processing chunk while scanning the survey. It does not change the analysis results, only how the work is split into batches. Larger chunks can process faster on datasets with many traces, while smaller chunks reduce the amount of data held per batch.

Default: 10000 traces. Minimum 1. Leave at the default for typical datasets; reduce it only if you need finer-grained progress reporting or are constrained on available data throughput.

Mute taper

Length of the smooth taper applied at the edge of the 4D mute before amplitude estimation. A gentle taper avoids introducing a sharp amplitude discontinuity at the mute boundary, which would otherwise bias the RMS amplitude measured near that boundary.

Default: 0.064 ms. Range 0 to 10000. Increase it if you see amplitude artifacts near the mute boundary; keep it small so it does not eat into valid signal close to the mute.

Output data

Amplitudes item

A per-record (per shot/receiver gather) log-amplitude table together with the survey's average amplitude level. This item is not seismic data by itself; it is the statistical result that downstream surface-consistent amplitude Edit and Apply modules read to derive and apply source, receiver and offset amplitude correction factors.

References

Taner, M. T. and Koehler, F., 1981, Surface consistent corrections: Geophysics, 46, 17-22.