A tutorial for processing a 2D land line using Seismic UnixKarl Schleicher ABSTRACT This paper described how to process a public 2D land line data set though a very basic processing sequence using Seismic Unix. The data from the north slopes of Alaska has good signal, although it may be suitable for testing ground roll attenuation programs. The detailed steps download the data from the internet and process it are described. You should be able to follow these steps and recreate my results. I hope this will accelerate the testing and validation of programs developed in research groups. The tutorial starts with background information like data downloading, region overview, data aquisition, and previous processing. The scripts and custom programs to translate to seismic unix, load headers, qc, apply preprocessing (including velocity filtering and decon), cdp gather, velocity analysis, and stack are listed and described. Header loading is not described in other Seismic Unix documentation. One approach to header loading is described here. The velocity analysis script is better than I found in previous papers. My effort to process these data is ongoing. I have not computed and applied residual statics. I have not migrated the data. My current results are not as good as obtained when the data was originally processed by GSI in 1981. I would like to provide my most current results to anyone who wants to use publicly available software to process seismic data. This paper is the beginning of an effort to build a library of open-access seismic datasets and processing scripts using open-source geophysical software. INTRODUCTION Seismic Unix (SU) is one of the best known open software packages for seismic processing. The distribution includes some example processing scripts and there are two books that teach how to use the software, Geophysical Image Processing with Seismic Unix (?) and Seismic Processing with Seismic Un*x (Forel et al., 2005) books cover broad subjects including basic Unix commands, setting up a user environment, basic seismic processing, and more advanced scripting for seismic processing. You can follow the text and recreate some seismic processing. These books to not provide much information about creating trace headers or preprocessing. /home/karl/data/alaska/31-81/clientfiles.SPT the textfile of shotpoint. This should accelerate the testing and validation of new seismic research. I concentrate on providing example scripts and programs to process a 2D land line using the processing system. I provide the custom programs I used to load the trace headers. velocity filter. moveout velocity. S609. I describe the data acquisition and previous data processing. longitude. BACKGROUND INFORMATION ABOUT THE DATASET President Warren Harding created the Naval Petroleum Reserve Number 4 in 1923.SGY L23537. The results in the deep section are similar to the results obtained in 1981.PDF the Observer’s log 3181.TIF A higher resolution stack in tif format I downloaded these files into my directory.SGY 3181O. I selected and processed line 31-81 because it was a short line from the most recent acquisition season. latitude. The parameters for deconvolution. I was able to view the large JPG and TIF files in OpenOffice.2 This paper assumes you are familiar with Seismic Unix. The scripts for preprocessing. Figure 1 is a map of the region and Figure 2 maps the lines collected and processed between 1974 and 1981. velocity analysis. and scaling can adapted for use by other seismic processing systems.org draw (other programs . and programs can be modified to allow you to validate your own ideas about seismic processing. This paper provides detailed steps that describe how to download the data from the internet and process it using seismic unix.SGY segy of the 1981 final stack 3181S. S609. The scripts. Currently I have not applied residual statics or migration. data. mute.PDF the surveyor’s log 3181.JPG A 1981 final stack in jpeg format. The files I found for line 31-81 are: L23535. You should be able to follow these steps and recreate my results. and stacking are provided and explained.SGY unprocessed seismic data in segy format L23536. Alaska (NPRA) in 1976. It was renamed the National Petroleum Reserve. The shallow section is not as good as previously obtained. These scripts provide the detailed parameters used by the Seismic Unix programs. 3 had problems).5 db/s. Common depth point stack 12. Time variant scaling DATA LOADING AND INITIAL DATA QC I found little documentation about loading data and creating trace headers in precious publications. 12 fold with a dynamite source. spherical divergence and exponentiation (alpha . Time-variant scaling (unity) 6. Velocity filtering dip range -12 to 4 ms/trace 4. The shotpoint interval is 440 ft and the receiver interval is 110 ft. The average shot depth is 75 ft. The processing applied by GSI in 1981 was: 1.4. Time Variant filtering 16-50 Hz at 700 ms 14-45 Hz at 1400 ms 12-40 Hz at 2000 ms 8-40 Hz at 400 ms 13. Designature deconvolution 5. The elevation plot on the section header shows the elevation is about 200 ft and there is little variation. Edit and true amplitude recovery 2.TIF to look at the side label that describes the acquisition and processing parameters. First Break Suppression 100 ms at 55 ft 380 ms at 2970 ft 700 ms at 5225 ft 11. . Normal moveout correction 9. final time . Apply datum statics 7. The data was acquired 96 trace. Automatic Residual Statics application 10. I zoomed the display of S609.5 s) 3. initial time . This section provides a detailed description.4. Velocity estimation 8.0 s. job. /home/karl/jobs/alaska/31-81/load/view1. view3. The final command in the view1. I wrote a custom java program to load the trace headers. The observers log. This plot allowed me to see that traces 1-96 were the data channels and 97-101 were the auxiliary traces. The surveyor log.3030) tracr 1 3030 (1 . The movie loops continuously and can be stopped by pressing s. The code is not elegant.000000) The print indicates there is little information in the input headers.job file is the sugethw. Once stopped.000000 (0.PDF defines the shotpoint elevations. This prints the fldr and tracf header keys. you can move forward or backward using the f and b.0.PDF describes the relationship between the su header keys ffid and ep (these are called REC. The segyread command translates data to SU format. This program require files to define the shotpoint elevation and the FFID/EP relationship. An example screen is shown in Figure 5. There are 31 shot records (fldr 101 . downloaded as: /home/karl/data/alaska/31-81/clientfiles/3181O.4 I created a script file to load the first segy file. and SHOTPOINT by in the observers log). downloaded as: /home/karl/data/alaska/3181/clientfiles/3181O. These auxiliary traces can be seen o nfigures 4 and 5.000000 0. This information was typed into two files listed in appendices 3 and 4. This file is listed in Appendix 1. hdrload2.job. The surange command prints: 3030 traces: tracl 1 3030 (1 . The parameter n2 is set to the number of traces in each shot record. which was based on the tracf range printed in surange (1 . The Observer Log indicates the first shotpoint is field file identifier (ffid) 110. There are also 5 auxiliary traces in each shot record.130) and each record has 101 traces (tracf 1 .job.101). These tests records are the unuisual traces in the left third of Figure 1.000000 .130) tracf 1 101 (1 101) trid 1 ns 3000 dt 2000 f1 0. These are the keys I used to map the data to the shotpoint and receiver locations. but it is straightforward to write and it works. The other two segy files were loaded by scripts view2.job This file is listed in appendix 5. The suxmovie command allows all the shots record on the line to be displayed. The first 10 records in the file are test records. It is listed in Appendix 2. The suximage produces Figure 1 and the zoom plot Figure 2. The program to load the headers was run by the script: /home/karl/jobs/alaska/3181/load/hdrload1. .job.101).3030) fldr 101 130 (101 . The way I developed this script is by pasting a command or two into a terminal window and picking information from the print of displays to write the next few commands. 5 0 1000 2000 3000 1 2 3 4 5 Figure 1: First 300 traces on the first tape. . 5 1. There are 101 traces in each shotpoint. 5 auxiliary traces and 96 data traces.First look at the data.6 1000 0 1050 1100 1150 1200 1250 0. . Notice the ground roll and good signal.0 1.0 Figure 2: Zoom of figure 1.5 2.5 3.0 2. 3 and velanQC.sh section 7. This script is listed in Appendix 9. These parameters are loosely based on the 1981 processing that used (-12. The script also includes suxmovie of the velocity filtered data. AND CDP SORT There is a bad shotpoint I removed. The semblance plots and CVS plot have the velocity function overplotted. Figure 7 is an example shot record after velocity filtering. Figure 9 is an example velocity analysis plot. SHOT RECORD VELOCITY FILTER I applied Velocity filtering (sudipfilt) to remove the groundroll. There are four components of the plot. Sudipfilter was intended for post stack processing. The stack file from the previous process was translated to SU format and displayed using the viewqcstack. semblance plot. These scripts differ from the previous scripts only by the names of the input and output file. This is a straight forward execution of segyread and suximage.7 and hdrload3. This allowed an asymmetrical dip filter to be applied (-15. VELOCITY INTERPRETATION I used a long script that combined several su program for velocity interpretation. constant velocity stack (CVS) plot. cmp gather without NMO and cmp gather after NMO. The velocities I picked are listed on Appendix 10. The script is more practical.5 ms/trace).job in the same directory. so a loop is required in the script to divide the data into individual shotrecords and seperate the positive and negative offsets. The script is listed in Appendix 8. Figure 8 is a display of two cdp gathers. The script hos more capabilities. It is listed in appendix 7. I also applied a mute and sorted the data to CDP order in the same script.2. Display of the checkstack is in Figure 6. The receivers leading the shotpoint were processed separately from the trailing receivers. /home/karl/jobs/alaska/31-81/load. 2005 (iva. MUTE. al.6.7. I combined the scripts from Forel et.sh section 8. . but it is tidier and a little shorter than Forel’s script.4).job script listed in appendix 6.2.2). because you can start from no velocity function. SHOT RECORD EDIT. or review and update and existing velocity field. This source signature removal applies the same operator to all traces in a shotrecord. 4. Considering all these differences. In general. PLANS Some of the ideas I have to continue this work include: 1. The script also applied AGC. especially below 400 ms.8 STACK The script that stacks the data is in Appendix 11. I think residual statics account for most of the differences. especially residual statics and migration. There are many differences in the application of AGC. The original processing includes residual statics. I think the results are surprisingly similar. The 1981 processing used GSI’s designature process. 3. 2. This was accomplished by removing the sign from the offset header and computing a time static from the offset. but it falls short of the commercial packages I have used. I wanted to start the decon design gate start time to increase with offset so the shallow data near the mute was not included. Many of my input errors were not trapped by the code. SU is a useful prototyping environment. I was disappointed that the processing applied 30 years ago produced better results than I obtained using SU. Sudipfilter was not intended for shotrecord velocity filtering. The filter is designed differently from conventional deconvolution and the two types of deconvolution will not produce data with the same wavelet. . Adding more processes. The shallow result on the SU processing is worse than the 1981 processing. I found the SU software hard to use. GSI used diversity stack to control the high amplitude noise bursts. so a collection of program were required. For example the GSI used to apply AGC before velocity filtering inverse AGC after velocity filter. The only way I knew how to do this us SU was to apply linear moveout to move the design gate start time to a constant time. COMPARISON OF THE SU AND THE 1981 RESULTS Figures 10 and 11 are the results created using SU and the results obtained in 1981. Some of the differences in the processing sequences are: 1. I compared the stack created in SU to the original processing results created in 1981 (figures 10 and 11). This script also applied decon using the command supef. Supef was bracketed with sustatic to apply and remove the offset dependent static. velocity analysis 6.sh in Appendix 9) improves the scripts in Forel’s book. Improve open source . Working on different datasets (marine. Make scripts and intermediate results available on the internet. The task of loading trace headers is no addressed in other publications.9 2.). The custom java program included in this paper is one way to complete this processing stage. My processing results can be recreated by others since the processing scripts are included in appendixes of this paper and the data can be downloaded from the internet. 3D. 3.. cdp gather 5. CONCLUSIONS I have provided a set of scripts the process a land line using SU.. Improve open source software. trace header creation 3. 3. Working on more data (Marine.. 3D. Adding more processes. . data load 2.) 4. 5. I was able to pick the velocities on this line using the script. stack Although this sequence omits important processes like residual statics and migration. The velocity analysis script (iva. especially residual statics and migration 2. it illustrates processing stages not presented by Forel or Stockwell. These scripts include the processing stages: 1.. Make scripts and intermediate results available on the internet 5. . velocity filtering 4. Process using other software (Open source of proprietary. 4. Some of the ideas I have to continue this work include: 1. Process using other software (Open source of proprietary. APPENDIX A SCONSTRUCT FILE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 from r s f . Benz. top= ’ n e r s l /NPRA/SEISMIC/1981/31 8 1 ’ . su L23536 .. s e r v e r= ’ http : / / certmapper . p r o j # need t o add t h e v e l o c i t y a n a l y s i s s c r i p t # need t o add m i g r a t i o n # need t o t r y s u d i v s t a c k ## # # # # # # # # ########## # Fetch t h e d a t a s e t and c o n v e r t t o m u l t i p l e r s f f i l e s ## # # # # # # # # ########## segyread = ’ ’ ’ s e g y r e a d b f i l e=${TARGETS[ 1 ] } h f i l e=${TARGETS[ 2 ] } t a p e=$SOURCE endian=%d ’ ’ ’ % (1− l i t t l e e n d i a n ( ) ) rawsegy =[ ’ L23535 ’ . and W.10 REFERENCES Forel. p r o j . Pennington. s e r v e r= ’ http : / / certmapper . D. u s g s . f i l e + ’ . ’ L23536 ’ . s t d i n =0) . su L23537 . ’ c a t L23535 . ’ L23537 ’ ] for f i l e in rawsegy : r s f . Seismic data processing with seismic un*x: Society of Exploration Geophysicists. 2005. s t d i n =0) r s f . a s c ’ ] .SGY ’ .SGY ’ . Fetch ( ’ 31 81 PR . D. gov ’ . rawsegy . T. bi n ’ . top= ’ n e r s l /NPRA/SEISMIC/1981/31 8 1 ’ . p r o j . d i r= ’DMUX’ ) Flow ( [ f i l e . f i l e + ’ . u s g s . Fetch ( f i l e + ’ . d i r= ’PROCESSED ’ ) # concatinate the input f i l e s Flow ( ’ l i n e ’ . gov ’ . c r . s e g y r e a d . f i l e + ’ .SGY ’ . c r . s u p r o j import ∗ import r s f . su ’ . ’ InterpText . ’ l i n e ’ . ’’’ . ’’’ java InterpText ’ ’ ’ . t x t ’ . ’ InterpText . ’ l i n e ’ . ’’’ suwind key=t r a c l min=1000 max=1250 tmin=0 tmax=3 | suximage p e r c =90 ’ ’ ’) #R e s u l t ( ’ f i r s t m o v i e ’ . ’’’ suwind key=t r a c l min=2324 max=2424 tmin=0 tmax=6 | suximage p e r c =90 ’ ’ ’) Flow ( ’ h d r f i l e . ’ suwind count =3000 | suximage p e r c =90 ’ ) Result ( ’ zoomfirst ’ . ’ h d r f i l e 1 . java ’ . s t d i n =0) Flow ( ’ h d r f i l e 1 . ’ sugethw output=geom key=t r a c l . t x t ’ . c l a s s ’ . ’’’ j a v a c ${SOURCE} ’ ’ ’ . t x t ’ .11 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 # d i s p l a y t h e f i r s t 3000 t r a c e s Result ( ’ f i r s t ’ . py ’ ] . py ’ ’ ’ . ’ l i n e ’ . ’ l i n e ’ . ’ I n t e r p T e x t . / I n t e r p T e x t . s t d i n =0) ( ’ h d r f i l e 1 .[ ’ h d r f i l e . t r a c f ’ ) #Flow # # # #Flow # # # ( ’ InterpText . f l d r . ’ l i n e ’ . t x t ’ . # ’’’ # suxmovie n2=101 l o o p=1 f f r a m e=1 dframe=1 # t i t l e =”r e c o r d %g ” p e r c =20 # ’ ’ ’) Result ( ’ f i r s t r e c 2 4 ’ . t x t ’ . s t d i n =0) Flow ( ’ b i n a r y h d r f i l e 1 . [ ’ h d r f i l e . ’’’ a2b n1=13 ’ ’ ’) . t x t ’ . class ’] . dat ’ . ’ b i n a r y h d r f i l e 1 . gelev . sy .12 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 keys= ’ ep . gx . c r . # ’’’ # suxmovie n2=96 l o o p=1 f f r a m e=1 dframe=1 # t i t l e =” a l l s h o t s r e c o r d %g ” p e r c =20 # ’ ’ ’) # d i s p l a y t r a c e s 1010−1250 f i r s t 3100 ms ( or 1550 s a m p l e s ) #R e s u l t ( ’ second ’ . # d i r =’PROCESSED ’ ) . # t o p =’ n e r s l /NPRA/SEISMIC/1981/31 8 1 ’ . cdp . ’ l i n e ’ . t r a c f . gov ’ .SGY ’ . ’’’ sushw i n f i l e =b i n a r y h d r f i l e 1 . t s t a t ’ Flow ( ’ a l l s h o t s ’ . u s g s . ’ \ ’ selev . [ ’ l i n e ’ . # s e r v e r =’ h t t p : / / certmapper . sstat . o f f s e t . gy . sx . # ’’’ # window f 2 =1010 n2=240 n1=1550 | # agc r e c t 1 =250 r e c t 2 =100 | # g r e y t i t l e =” F i r s t 3000 t r a c e s ” p c l i p =70 # ’ ’ ’) #Fetch ( ’ 3 1 81 PR . gstat . dat key=%s | sushw key=f 1 a=0 | suwind key=cdp min=−999998 max=999999 | suwind key=ep min=−999998 max=999999 | suwind key=ep r e j e c t =149 ’ ’ ’ % keys ) #R e s u l t ( ’ t e s t ’ . ’ a l l s h o t s ’ . dat ’ ] . 09721 . s t d i n =0) Result ( ’ checkstack ’ . a s c ’ ] . tnmo ) ) #vnmo = ’ . ’ . . 3 3 9 . 8 1 2 4 . j o i n (map( s t r . 9 7 2 1 . 7 0 7 .859 . 0 9 1 . sh ’ . j o i n (map( s t r . ’ 31 81 PR . / ${SOURCES[ 1 ] } 100 155 ’ ) #R e s u l t ( ’ m o v i e v e l f i l t ’ . . 6 0 7 .2. 6 5 2 . 1 2 5 .SGY ’ .000] #vnmo = [ 7 75 2 . s e g y r e a d + ’ ’ ’ | sushw key=n t r a=534 | sushw key=d1 a=0 ’’’. 6 0 7 .358 . 3 3 9 .12518 . # 08931 . 7 9 6 4 . 7 0 7 . ’’’ suwind key=t r a c l min=2324 max=2424 tmin=0 tmax=6 | suximage p e r c =90 ’ ’ ’) # s e r g e y d i d t h i s . 1 . 8 9 3 1 . 0 0 0 ’ vnmo= ’ 7 7 5 2 . .2. 8 7 5 4 . 3 5 8 .6. 8 5 9 .10742 . . 1 . ’ suximage t i t l e =”c h e c k s t a c k ” p e r c =90 ’ ) R e s u l t ( ’ zoomcheckstack ’ . 1 .1. f i l e + ’ . 1 0 4 2 5 . 1 2 5 .13 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 # c o n v e r t s t a c k and view i t : f i l e=’ checkstack ’ Flow ( [ f i l e . . 1 . # ’’’ # suxmovie n2=96 l o o p=1 f f r a m e=1 dframe=1 # t i t l e =”r e c o r d %g ” p e r c =20 # ’ ’ ’) Result ( ’ v e l f i l t r e c 2 4 ’ . I j u s t used a s t r i n g #tnmo = [ 0 0 0 0 . ’ checkstack ’ . 6 .652 . ’ a l l s h o t s a l a s k a v e l f i l t . . ’’’ s u s o r t cdp | . 1 6 5 5 2 ’ Flow ( ’ v e l f i l t c d p s m u t e ’ . ’ . 8 7 2 . 8 1 2 4 . 3 4 9 . 1 0 7 4 2 . ’ a l l v e l f i l t s h o t ’ . ’ c h e c k s t a c k ’ . b u t i t d i d not work . # 1. 8 0 7 4 .2. ’ . 1 2 5 1 8 . ’’’ suwind tmin=0 tmax=3 | suximage t i t l e =”zoom c h e c k s t a c k ” p e r c =90 ’ ’ ’) Flow ( ’ a l l v e l f i l t s h o t ’ . 2 . 7 9 6 4 .091 .10425 . 7 7 8 1 . 8 7 2 . 2 . . 7 7 8 1 . 2 . vnmo ) ) tnmo= ’ 0 0 0 0 .16552] # #tnmo = ’ .349 . ’ a l l v e l f i l t s h o t ’ . 0 8 75 4 . . bi n ’ . f i l e + ’ . ’ a l l v e l f i l t s h o t ’ . 8 0 7 4 . 2970 . t x t ’ ] . . ’ v e l f i l t c d p s m u t e ’ . # ’’’ # suxmovie n2=96 l o o p=1 f f r a m e=1 dframe=1 # t i t l e =”r e c o r d %g ” p e r c =20 # ’ ’ ’) R e s u l t ( ’ cdp250 −251 ’ .2 p n o i s e =.55 . 1 0 0 .5225 \ tmute = . 7 0 0 .01 mincor =. −55 . ’’’ suchw key1=t s t a t key2=o f f s e t a=−200 b=.0861 | sustatic hdrs=1 s i g n =1 | supef maxlag =. 2 8 0 . . 1 0 0 . 2 8 0 .14 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 sunmo tnmo=%s vnmo=%s | sumute \ xmute = −5225 . .25 maxcor=5 | sustatic hdrs=1 s i g n=−1 | sunmo . ’ v e l f i l t c d p s m u t e ’ . 7 0 0 \ mode=0 \ key=o f f s e t | sunmo tnmo=%s vnmo=%s i n v e r t =1 ’ ’ ’ % ( tnmo . ’ v p i c k . vnmo ) ) #R e s u l t ( ’ m o v i e c d p s ’ . ’’’ suwind key=cdp min=250 max=251 tmin=0 tmax=3 | suwigb p e r c =90 ’ ’ ’) Flow ( ’ v e l f i l t c d p s n m o ’ . −2970 . vnmo . tnmo . [ ’ v e l f i l t c d p s m u t e ’ . . . 2970 . 1 0 0 . 7 0 0 mode=0 key=o f f s e t ’ ’ ’) #R e s u l t ( ’ m o v i e v e l f i l t c d p s n m o ’ . ’’’ suwind tmin=0 tmax=3.0 tmax=3. compare # velanalysis after residual statics . # ’’’ # suxmovie n2=96 l o o p=1 f f r a m e=1 dframe=1 # t i t l e =” v e l f i l t c d p s n m o r e c o r d %g ” p e r c =20 # ’ ’ ’) Flow ( ’ b r u t e s t a c k ’ . . .0 | suximage t i t l e =”b r u t e s t a c k ” p e r c =90 ’ ’ ’) # do i n v e r s e nmo .5225 tmute = .15 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 par=v p i c k . t x t | sugain agc=1 wagc =. ’’’ sustack key=cdp normpow=1 ’ ’ ’) Result ( ’ brutestack ’ . ’’’ suximage t i t l e =”b r u t e s t a c k ” p e r c =90 ’ ’ ’) R e s u l t ( ’ zoomb rutestack ’ . 2 8 0 . ’ v e l f i l t c d p s n m o ’ . ’ b r u t e s t a c k ’ .1 | sumute xmute =55 . Flow ( ’ s t a t i c s i n ’ . ’ brutestack ’ . 1 f u n c t i o n nmo and compare r e s i d u a l s t a t i c s .0 | suresamp r f =2 ’ ’ ’) 252 253 254 255 256 257 258 259 . ’ v e l f i l t c d p s n m o ’ . ’’’ suwind tmin =1. ’ v e l f i l t c d p s n m o ’ . . ’ statics in ’ . s t d o u t =0) R e s u l t ( ’ s o u r c e s t a t i c ’ . dat r s o l=r e c s t a t i c . dat ’ . dat ’ . ’’’ sushw key=t s t a t a=0 | sushw key=s s t a t a=0 | sushw key=g s t a t a=0 | sustatic hdrs=3 s o u f i l e=${SOURCES[ 1 ] } r e c f i l e =${SOURCES[ 2 ] } ns =167 nr =668 no=96 | sustack key=cdp normpow=1 ’ ’ ’) Result ( ’ rstack ’ . ’ r s t a c k ’ . ’ suximage t i t l e =” r s t a c k ” p e r c =90 ’ ) R e s u l t ( ’ zoomrstack ’ . dat r e c s t a t i c . dat n i t e r =5 n t r a c e s =5280 n t p i c k =100 samples nshot =167 nr =668 nc=636 s f o l d =96 r f o l d =96 c f o l d =48 v e r b o s e=1 ’ ’ ’ . ’ rstack ’ . ’ s o u r c e s t a t i c . dat r e c s t a t i c . dat ’ . ’’’ suresstat \ s s o l=s o u r c e s t a t i c . dat ’ . ’ r e c s t a t i c .16 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 Flow ( ’ s o u r c e s t a t i c . ’ v e l f i l t c d p s n m o s o u r c e s t a t i c . ’ xwigb n1=668 t i t l e =” r e c e i v e r s t a t i c ” ’ ) Flow ( ’ r s t a c k ’ . ’ xwigb n1=167 t i t l e =”s o u r c e s t a t i c ” ’ ) R e s u l t ( ’ r e c s t a t i c ’ . ’ mig ’ . [ ’ r s t a c k ’ . ’ premig ’ . ’ 010 V e l o c i t y I n t e r p I V A . / 0 1 0 V e l o c i t y I n t e r p I V A . i n t p 2 . i n t p 2 . / mig . sh ’ . ’’’ ximage n1=3000 d1 =. ’ s t k v e l 1 . ’ mig ’ . ’ premigstack ’ .002 f 2 =101 d2=1 cmap=rdb11 ’ ’ ’) Flow ( ’ mig ’ .0 | suximage t i t l e =” r s t a c k ” p e r c =90 ’ ’ ’) Flow ( ’ s t k v e l 1 . ’ .5 s i g n =1 | suktmig2d v f i l e =s t k v e l 1 . sh ’ ’ ’) R e s u l t ( ’ v f i l e ’ . sh ’ ) Flow ( ’ p r e m i g s t a c k ’ . i n t p 2 .17 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 ’’’ suwind tmin=0 tmax=3. ’ s t k v e l 1 . ’’’ s u f r a c power =. ’’’ susort | sustack key=cdp normpow=1 ’ ’ ’) Result ( ’ premigstack ’ .0 | suximage t i t l e =”mig” p e r c =90 ’ ’ ’) # i t l o o k s l i k e one o f f s e t i s used f o r t h e whole o f f s e t g a t h e r # documentation s a y s use s u f r a c b e f o r e m i g r a t i o n Flow ( ’ premig ’ . ’’’ . ’ s t k v e l 1 . ’’’ suximage t i t l e =”mig” p e r c =90 ’ ’ ’) R e s u l t ( ’ zoommig ’ . b in dx=55 h o f f s e t =0 ’ ’ ’) R e s u l t ( ’ mig ’ . bi n ’ . [ ’ v e l f i l t c d p s n m o ’ . i n t p 2 . ’’’ suwind tmin=0 tmax=3. bi n ’ ] . t x t ’ . i n t p 2 . bi n ’ . b i n ’ ] . . ’ v p i c k . 200 . ’ p r e m i g s t a c k ’ .8 .18 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 ’’’ s u f i l t e r f =4 .8 .240 | suwind tmin=0 tmax=3. ’’’ suxmovie n2=536 l o o p=1 f f r a m e=1 dframe=1 t i t l e =”r e c o r d %g” p e r c =20 ’ ’ ’) End ( ) .240 | suximage t i t l e =”p r e m i g s t a c k ” p e r c =90 ’ ’ ’) R e s u l t ( ’ zoompremigstack ’ . ’ premig ’ . ’’’ s u f i l t e r f =4 .200 .0 | suximage t i t l e =”p r e m i g s t a c k ” p e r c =90 ’ ’ ’) P l o t ( ’ premigmovie ’ .
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