|
<< Click to Display Table of Contents >> Navigation: Analysis > Energy calculator |
The Energy Calculator module computes the local seismic energy distribution across a gather by calculating the mean squared amplitude within a 2D sliding window. For every sample in the gather, the output value represents the average of the squared amplitudes of all non-zero samples that fall within the specified window around that sample in both the trace and time directions. This provides a smooth, spatially-averaged energy map that reveals how signal energy varies with offset (or trace number) and time simultaneously.
Use this module to diagnose amplitude anomalies, evaluate gain recovery effectiveness, identify muted or dead zones, and QC the energy balance across a CMP or shot gather. Muted (zero-amplitude) samples are automatically excluded from the window average, so energy estimates remain unbiased near mute boundaries. After processing, a per-trace RMS amplitude chart is displayed as an overlay, allowing quick identification of outlier traces or offset-dependent energy trends.
The algorithm uses a 2D summed-area table (integral image) internally, which makes the computation time independent of window size — large windows run just as fast as small ones. The output gather has the same dimensions as the input gather.
The seismic gather on which energy analysis is performed. This is typically a CMP gather, shot gather, or any pre-stack or post-stack section. The input may be in the time domain or the depth domain. Muted samples (zero amplitude) are treated as absent and do not contribute to the energy average.
Controls the lateral extent of the energy averaging window in the trace direction. The value specifies the half-width: a setting of N means the window spans N traces on each side of the current trace, giving a total window width of up to 2N + 1 traces. The window is automatically clipped at the gather edges, so no padding or wrap-around is applied.
Default: 10 traces. Increase this value to obtain a smoother, more spatially averaged energy map; decrease it to resolve finer lateral energy variations. For narrow gathers with few traces, a value of 3 to 5 is usually sufficient.
Controls the vertical extent of the energy averaging window in the sample (time or depth) direction. Like Window X, this is a half-width: a setting of N means the window spans N samples above and below the current sample, giving a total window height of up to 2N + 1 samples. The window is clipped at the top and bottom of the trace.
Default: 10 samples. Larger values produce a smoother energy envelope along the time axis, useful for detecting broad amplitude trends. Smaller values preserve sharp time-localized energy changes such as those associated with reflectors or noise bursts. For a typical 2 ms sample interval, 10 samples corresponds to a 20 ms half-window (40 ms total).
The energy gather. Each sample contains the mean squared amplitude computed over the 2D sliding window centred at that sample position. The output gather has the same number of traces and samples as the input. Samples that fall in regions where all contributing input samples were zero (i.e., fully muted zones) will have an output value of zero. The output can be connected to downstream visualisation or attribute extraction modules.
A per-trace RMS amplitude chart is automatically computed and displayed as a vista overlay after each execution. For each output trace, the module calculates the root-mean-square of all non-zero energy values along that trace (i.e., the square root of the mean of the windowed energy samples), then plots it against trace number. This chart provides a quick summary of the lateral amplitude balance across the gather, making it easy to spot traces with anomalously high or low energy.