http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
effects of digitization on the dynamic range of Vibroseis signals
(i.e., many signals must be averaged) is required to control
1/0 relation approximated a straight line provided that the
4, 2, and 1 bit on: 1) the dynamic range, 2) the S/N ratio,
acceptable results compared with the 16-bit digitization.
also showed that they acted like noise for each other which
amplitudes of -54 dB relative to the primary signals were
and 3) the input/output relationship were investigated. The
bits increased. In the presence of gaussian noise however,
bits than required to achieve the desired dynamic range. The
by the numbers of bits used in the digitization. However, for
delectability. However, these two properties were reduced as
digitization of Vibroseis signals showed comparable and
drastically reduced the digitization distortion of both
effects of digitization of Vibroseis signals using 16, 8, 6,
function of the sweep duration (number of samples), the
generating the fmal seismic section. Therefore, it is not
Hence, the recording instruments need not utilize more binary
improved. The input/output (I/O) relation changed from a
increased the dynamic range and the small-signal
individual samples of a redundant signal are combined in
instruments to measure a small signal accurately in the
it is shown that, for sign-bit and 2-bit digitizations, the
nature of degradation of the digitized Vibroseis signals
necessary to have the full dynamic range and precision in the
noise standard deviation is larger than the signal (i.e.,
non-redundant signals, the dynamic range is directly affected
number of (fixed) source repetitions, and the number of
presence of a large signal or in the presence of noise. For
raw data to achieve the desired quality of the final section.
recovered in the presence of another strong signal (primary)
redundunt signals such as Vibroseis, the dynamic range is a
requires sufficient dynamic range in the recording
S/N<I.O) because noise provided a background that randomized
signals which occurs in the absence of noise. The 8-bit
stair-step like (nonlinear) to a sight line as the number of
the amount of noise present. Overlapping Vibroseis signals
The detection of geologic reflectors in seismic signals
the digitization distortion. However, sufficient redundancy
the number of bits was decreased. The S/N ratio was also
traces in a common-depth point (CDP) stacking because the
varied with the number of bits used. The Vibroseis method
With an 8-bit digitizes, small Vibroseis signals with