A comparison of seismic trace summing techniques
Geophysics, 45 (6):
1017--1041 (Jun 1, 1980)DOI: 10.1190/1.1441104
Abstract
The results of an analysis and comparison of mantissa only, sign bit,
true amplitude, automatic volume control, and diversity stack signal
trace summations are presented. The results show that under conditions
frequently encountered for low-level sources, all these summation
methods preserve the fidelity of input signals to within a time variant
scale factor. The value of the signal-to-noise (S/N) average power
ratio of the true amplitude summer is shown to be much more sensitive
to intertrace noise variance differences than the other summing techniques.
Excessive signal distortion may occur for mantissa only or sign bit
summers when instantaneous input signal magnitude is large in comparison
with the input noise standard deviations of the summed data. There
will be no significant differences in the performance of mantissa
only and sign bit summers under conditions frequently encountered
for low-level sources. The effects of signal summation methods are
not directly dependent upon any instantaneous gain ranging characteristics
of the amplifier used to create the input data.