Sigsbee2 Models

Sigsbee 2B Models

The Sigsbee 2B model contains the same general geometry as the 2A model except for a more realistic water to floor boundary which results in multiple generation when shots are modeled on it. However, dealing with the files is basically identical the headers should also be calibrated as shown in Table 2.

Table 4 shows the contents of the sigsbee/model2b/SConstruct script. This file is quite similar to the one found in the Sigsbee 2A section and contains a list of rules that fetch the datasets and plot them.

from rsf.proj import *

 #######################################  
 # Sigsbee 2B velocity model construct #
 #######################################

PRFX = 'sigsbee2b_'
SUFX = '.segy' 

for c in ('migration_velocity','stratigraphy','reflection_coefficients'):

    if(c=='migration_velocity'):
        v='vmig2B'
        o=3.055
        d=.0143
        s=.0003048
        l='Migration Velocity'
        a='y'
        u='kms'
    if(c=='stratigraphy'):
        v='vstr2B'
        o=3.048
        d=.00762
        s=.0003048
        l='Stratigraphic Velocity'
        a='y'
        u='kms'
    if(c=='reflection_coefficients'):
        v='reflectionCoefficients2B'
        o=3.048
        d=.00762
        s=1
        l='Reflection Coefficients'
        a='n'
        u=''
    h = c + 'head'
    t = PRFX + c + SUFX
    Fetch(t,'sigsbee')

    Flow([v,h],t,
         '''
         segyread tape=$SOURCE tfile=${TARGETS[1]} |
         put
         o1=0  d1=.00762   label1=Depth    unit1=km
         o2=%f d2=%f       label2=Distance unit2=km
         | scale rscale=%f
         ''' %(o,d,s) ,stdin=0)

    Result(v,v,'''grey color=i scalebar=y allpos=%s screenratio=.375 screenht=3
                  wheretitle=t title=%s labelsz=4 titlesz=6 barlabel=%s''' % (a,l,u))

End()

Table 4. Contents of model2B/SConstruct script.

Typing Command 2 within the sigsbee/model2B directory runs the script.

$$\texttt{bash-3.1\$\ scons\ view}$$ (2)

A plot of the migrated velocity model is shown below Figure 2b while the stratigraphic model can be seen in Figure 2a. A plot of the reflection coefficients are shown in Figure 2c.

vstr2B,vmig2B,reflectionCoefficients2B
Figure 2. Sigsbee 2B contains two velocity models, a stratigraphic model (a) and a migrated model(b). The resulting reflection coefficients are shown in (c).

Sigsbee2 Models