Page 150 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

the
frequency. Ratios of sidelobes to central
thus have the same defining power;
two octaves of
lowest.
three pulses are
resolution. Definition.
Improving seismic
the highest
the pulses in (a)
the
133
four times
peaks for each of the
bandwidth, because
Waveform
frequencies are
definition and
Compared to
5.35
FIGURE
Seismic
and

Bandwidth
0.1
Octave
One
0.1
0.1
a)
RR
rae mee PFE.
eR
He
an
Hz span one octave, because Pulses in (a) Hz - 80 40 20 Hz - 10 their bandwidths represent doubling of 10-70 on pulses span same. In (b) ye pulses the aise ratios higher peak-to-sidelobe have (b) in and, hence, higher definition. Resolution. pulses span one octave, (a) each of the In Vr to left resolution is higher going from higher right, however,
to define
music
Waveform Analysis ad) : 3” 2 > 0 8 o28 and, hence, the same 40 that defining power is zero. peak main is better able broadens, improving seismic definition. octaves as in frequency the times sidelobes have Increasing the pulse, mak- main Interpretation frequencies frequency of 40 the of widths bandwidth, broad Hz) (40-40 might interface encompassing resolution improves 5.35
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0.05
Ss
And ————> Hz 3s sieaseah a edsiatas 3 im Ft =— \| e@sgses ~~ Hz) (40 potential to define interfaces. a) Single, Hz pulse 0s), so the between the pulse that sense same four will octave of the 5.35b). high both central the with the bandwidth an that definition, that same. the bandwidth signal bandwidth.
Processing, 20-60 c) 2 q q ee Frequency (Hz) frequency = (at Time 0.0125 s) ~ ( troughs, so the of in one octave; one (Fig. 5.35a). amplitude the (Fig. present Bandwidth have pulse with each (compare definition, however, no the define to with poor Note Hz). remains of octaves Hz 20-80 broad
Acquisition, Definition 0.064 =| 2 0 23 the same central have the central peak time than adjacent ratio increases as bandwidth thought be by up steps only spanning main the pulse relative to interface is Broad and input the pulses, four of resolution and spike, ability no pulses of 40-80 Hz; definition but because two Note the that frequencies and
Reflection: I<VRSR Frequency (Hz) pulses to (d), improving the as Hz pulse spans the same peak has higher amplitude pulse can frequency A pulse of those to sidelobes an where Frequencies requires that shows 5.34 power same different a approaching with wave, comparison 20-40 Hz; pulse, definition, Hz). high
Seismic Increasing oR Increasing seismic definition. The increases from (a) the same amplitude (a), 30-50 a Peak-to-sidelobe amplitude seismic of a the Doubling octaves. two size in attenuates the to define of High stratigraphy Fig, with the pulses portray signal sine pure a shows (10-20 frequency better 10-40 Hz; 20-80 includes both
Chapters . Hz 40 - sR 8eeg (Hz) =~ Bandwidth have lobes in pulse the central (troughs). The 0.c,d) = bandwidth (Fig. 5.35). expands by comparable of octaves easier it Importance detail of bandwidth. broad each thus and pulses). The Hz 10-70 revealing a present. Fig. 5.35a octave one only with higher the much trates Hz; (5-20 it because
132. a) 40 —— © Frequency 5.34 of resolution. wave; side to Compared at Time are ing .
g
Ss
8 (9) ouny FIGURE pure sine b) sidelobes interface