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Shot Records

The file marmrefl.hh contains the shot data collected on the Marmousi model. The survey was an off end survey with receivers to the left of the source being pulled towards the right. Receiver as well as shot spacing is every 25 meters. Near offset is 425 meters from the source. 726 time gates were recorded with 4ms spacing for roughly 3 seconds of data collection. Madagascar correctly converts this file according to its header; however, the correct shot header values are reproduced in Table 4.

n1=726 d1= 0.004 o1=0.000 label1=Depth unit1=s  
n2=96 d2=-0.025 o2=2.575 label2=Offset unit2=km  
n3=240 d3= 0.025 o3=3.000 label3=Shot-coord unit3=km  

Table 4. Shot header information for Marmousi.

The file marmousi/shots/SConstruct gathers shot data, appends the header as necessary and produces several plots of the data. This file is reproduced here in Figure 5

from rsf.proj import *
# Fetch Files from repository

# Convert Files to RSF and update header
Flow('marmrefl','marmrefl.hh', '''dd form=native | put
    label1=Depth Z label2=Offset unit2=km unit1=sec
    label3=Position unit3=km d2=-.025 d3=.025 o2=2.575 o3=3''')

# Plotting Section
#Result('marmrefl','window j3=10 | grey')

Result('nearOffset','marmrefl','''window $SOURCE min2=.200 max2=.200 size2=1 | 
    grey color=I gainpanel=a title=Near Offset Data label1=Time label2=Position
    screenratio=1.3 labelsz=4 titlesz=6 wheretitle=t''')

Result('shot20','marmrefl','''window $SOURCE min3=3.500 max3=3.500 size3=1 | 
    grey color=I gainpanel=a title=Shot # 20 wantframenum=y label2=Offset
    label1=Time screenratio=1.3 labelsz=4 titlesz=6 wheretitle=t''')

Table 5. SConstruct script generating the Marmousi shot images

To run the script type Command 2 within the marmousishots directory.

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

Figure 2.
Shot number 20 of Marmousi synthetic survey dataset. Shot position in km is shown in the lower left hand corner.
[pdf] [png] [scons]

Figure 3.
Near offset data for Marmousi model
[pdf] [png] [scons]

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Next: Finite Difference Modeling Up: Marmousi Model Previous: Model