Sigsbee2 Models

Sigsbee 2A Models

The Sigsbee2A velocity and reflection coefficient models are easily viewed using Madagascar. There are 2 velocity models, a smooth migrated model and a true stratigraphic model. The SCons script sigsbee/model2A/SConstruct contains a set of rules that tell Madagascar to fetch the data append the headers and make several plots. This script is reproduced in Table 3.

from rsf.proj import *

 ####################################### 
 # Sigsbee 2A velocity model construct # 
 #######################################

PRFX = 'sigsbee2a_'
SUFX = '.sgy' 

for c in ('migration_velocity','stratigraphy','reflection_coefficients'):
    if(c=='migration_velocity'):
        v='vmig2A'
        o=3.055
        d=.01143
        s=.0003048
        l='Migration Velocity'
        a='y'
        u='km/s'
    if(c=='stratigraphy'):
        v='vstr2A'
        o=3.048
        d=.00762
        s=.0003048
        l='Stratigraphic Velocity'
        a='y'
        u='km/s'
    if(c=='reflection_coefficients'):
        v='reflectionCoefficients'
        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 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))

    Result(v,v,'''window f1=1 | grey color=i scalebar=y allpos=%s screenratio=.375 screenht=3 barreverse=y
    wheretitle=t title=%s labelsz=4 titlesz=6 barlabel=Velocity barunit=%s''' % (a,l,u))

End()

Table 3. Contents of model2A/SConstruct script.

Typing Command 1 within the sigsbee/model2A directory runs the script.

$$\texttt{bash-3.1\$\ scons\ view}$$ (1)

The Sigsbee2A migrated and stratigraphic velocity models are shown in Figures 1a and 1b respectively. A plot of the reflection coefficients are shown in Figure 1c.

vmig2A,vstr2A,reflectionCoefficients
Figure 1. Sigsbee 2A contains a stratigraphic velocity model (a) a migrated smoothed model (b) and a reflection coefficient model (c).

Sigsbee2 Models