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COMPUTER PROGRAMS IN SEISMOLOGY

An UpdateSeptember 26, 2007

Bob Herrmann, SLU

with assistance and inspiration ofChuck Ammon, PSU

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Outline

1. History2. Documentation and Tutorials3. Recent Uses4. Scripting5. Installation6. What's New7. Plans8. Research Needs9. User Needs

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1. History• 1975 – Spectral analysis, source

inversion, initial synthetics, punched cards

• 1985 – UNIX, minicomputers, implement synthetic seismogram algorithms, dispersion inversion

• 1996 – LINUX/UNIX – emphasis on simplified use

• 2007 -

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Platforms• LINUX

• Solaris

• CYGWIN (Windows 2K/XP) (full LINUX environment with X11 for Windows – with all tools, e.g., ImageMagick, latex, groff, compilers, python, perl etc for free!)

• MacOS-X

rdseed/evalresp/CPS all work!!!

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Why?• Need standard tools for routine

processing of large data sets

• Fewer programmers, and greater emphasis on canned techniques

• Need to quickly instill a modern skill set for student researchers

• Need to permit all researchers to work with modern digital data

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20 years of Computers

• Computers get faster

• Storage increases

• Write code that emphasizes clarity and reuse

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2. Documentation and Tutorials

• Documentation provides examples• Programs give on-line help:

– fmplot -h• Tutorials with scripts and data sets to

assist users

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• Wavenumber integration

• Surface waves• Generalized Ray• Asymptotic Ray

Theory• TI for omega-k

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• Waveform and spectral amplitude inversion

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• Procedures and computation of Green's functions

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• Dispersion measurements

• Receiver function determination

• Joint inversion

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• Complete graphics package in FORTRAN and in C

• X11/PostScript

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• Compatible with sac2000

• No SAC code• Written in C • Simple

organization• sac IO libraries

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• Processing scripts are up-to-date• Tutorials are close to up-to-date• PDF's need updating

Why? Data streams evolve as do processing techniques

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Tutorials• Determination of Receiver Functions• Inversion of Surface-Wave Dispersion and

Receiver Functions for Structure• Surface-Wave Synthetics and Group Velocity

Determination• Surface-Wave Synthetics and Phase Velocity

Determination• Phase velocity determination using a seismic

network and a real data set New SEP 25 2007!• SEED - Unpacking to SAC, Deconvolving and

Rotating• Cross-correlation of Ground Noise - Example for

southeastern Spain• Particle motion plots for focal mechanisms

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3. Recent Uses

• Source inversion• Group velocity tomography• Shallow seismic investigations

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Moment Tensor

• www.eas.slu.edu/Earthquake_Center/MomentTensor.html• North America

– Teleseisms– Korea– Europe– Middle East

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US Earthquakes: (red 2007)Focus in on non-CA earthquakes – > 200 events

Direction of maximum compressive axis and faulting style: red – normal, blue – thrust, green - strike-slip

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Scripting Inversion Review

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Tomography ComparisonSLU Colorado

Regional earthquake data Greg Benson – noise studiesPercentage deviation about 3.2671 km/sec for 8 sec Love waves (2278 rays)

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Red: CUS model; black SLU EQ tomography: red Colorado noise tomography

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Red: CUS model; black SLU EQ tomography: red Colorado noise tomography

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Red: WUS model; black SLU EQ tomography: red Colorado noise tomography

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4. Scripting

• Organization is essential, especially if operations are to be repeated often, e.g., for source inversion

• Use SHELL scripts (bash is the default on LINUX/CYGWIN/MacOS-X)

• Comment everything in great detail

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Case Study – Source Inversion

Script for regional source inversion to• get waveforms• deconvolve instrument response• QC data for inversion• invert for source parameters• document as web page with all

graphics

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DO#!/bin/sh###### valid regions# REG Region FELTID VELOCITY_MODEL# HI Hawaii hi [Not implemented June 23, 2007]# AK Alaska ak CUS (in continent from Rockies -no deep)# CA California ca WUS# PNW Pacific Northwestrn pnw WUS# IMW Intermountain west imw WUS# CUS Central US cus CUS# NE Northeastern US ne CUS# ECAN Eastern Canada ous CUS (in continent from Rockies)# WCAN Western Canada ous [Not implemented June 23, 2007]###### Command syntax:#DOCWBREG YEAR MO DY HR MN SC MSC LAT LON DEP MAG REG NEIC FELTID#####DOCWBREG 2007 09 01 18 32 02 000 41.64 -112.33 1.0 3.7 IMW UU00007689 X7535_07

Actually a prototype for an automatic initiation of processing

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DOCWBREG (271 lines)

• Create Event Directory and sub-directories

• Populate with region processing scripts

• Get waveforms in SAC and responses in SAC pole-zero format

• then invert, and then

• create documentation page

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###### Now start all the processing#####cd ${MYPWD}/${DIR}/${DIR}CWBDOEVT###### form Z R T at the same time ensure that signal amplitudes# are absolutely bounded by 1.0e-10#####cd ${MYPWD}/${DIR}/${DIR}CWBDOROT###### Decimate the traces for surface-wave studies#####cd ${MYPWD}/${DIR}/${DIR}CWBDODEC###### for waveforms inversion select the distance range#####CWBDODIST###### QC for traces for waveform inversion#####CWBDOQC

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CWBDOEVTfor TRACE in *.SACdoKSTNM=`saclhdr -KSTNM $TRACE`KCMPNM=`saclhdr -KCMPNM $TRACE`DELTA=`saclhdr -DELTA $TRACE`FHH=`echo $DELTA | awk '{print 0.50/$1}' `FHL=`echo $DELTA | awk '{print 0.25/$1}' `DOY=`saclhdr -NZJDAY $TRACE`###### we will not rewrite the KNETWK and KHOLE in the headers with new values# we will just repeat the following steps in the script#####KNETWK=`saclhdr -KNETWK $TRACE`if [ ${KNETWK} == "-12345" ]then NET=""else NET=${KNETWK}fiKHOLE=`saclhdr -KHOLE $TRACE`if [ -z ${KHOLE} ]then LOC=""else if [ ${KHOLE} == "-12345" ] then LOC="" else LOC=${KHOLE} fifi

Note use of SHELL variables and program saclhdr

Use saclhdr to get header values

Clean up header

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###### fill in the headers with the event information# Also deconvolve to ground velocity in meters per sec# The CWB database has the gains in nanometers so# we will divide the deconvolved trace by a 1.0e+9## As a result the annotated (headers set) original trace will# be in ../GOOD as StationComponent.S# The deconvolved trace will be in ../GOOD as# StationComponent.sac######gsac << EOFr $TRACEch EVLA $LAT EVLO $LON EVDP $DEPch OCAL $YEAR $MO $DY $HR $MN $SEC $MSECch lovrok truech lcalda truewhrtr#### gsac comment###transfer from polezero subtype RESP.${KNETWK}.${KSTNM}.${LOC}.${KCMPNM} TO VEL \

FREQLIMITS 0.002 0.003 ${FHL} ${FHH}div 1.0e+9w ../${DEST}/${KSTNM}${KCMPNM}.${NET}.${LOC}.sacquitEOF

###### end deconvolve the trace#####done

Note use of calendar time instead of Julian time

The passband periods are stored in USER1

USER2

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Deconvolution with IRIS rdseed RESP files

for i in *.SACdoKSTNM=`saclhdr -KSTNM $i`KCMPNM=`saclhdr -KCMPNM $i`DELTA=`saclhdr -DELTA $i`DOY=`saclhdr -NZJDAY $i`FHH=`echo $DELTA | awk '{print 0.50/$i}' `FHL=`echo $DELTA | awk '{print 0.25/$i}' `###### we will not rewrite the KNETWK and KHOLE in the headers with new values# we will just repeat the following steps in the script#####KNETWK=`saclhdr -KNETWK $i`if [ "${KNETWK}" = "-12345" ]then NET=""else NET=${KNETWK}fiKHOLE=`saclhdr -KHOLE $i`if [ "${KHOLE}" = "-12345" ]then LOC=""else LOC=${KHOLE}fiDOY=`saclhdr -NZJDAY $i`cp RESP.${NET}.${KSTNM}.${LOC}.${KCMPNM} resp

Use sample rate to define Nyquist and deconvolution band

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Aside: Deconvolution with IRIS rdseed RESP files

evalresp ${KSTNM} ${KCMPNM} ${YEAR} ${DOY} 0.001 ${FHH} 2049 -u 'vel' -f respgsac << EOFr $ich EVLA $LAT EVLO $LON EVDP $DEPch OCAL $YEAR $MO $DY $HR $MN $SEC $MSECch lovrok truech lcalda truewhrtrtransfer from eval subtype AMP.${NET}.${KSTNM}.${LOC}.${KCMPNM} \ PHASE.${NET}.${KSTNM}.${LOC}.${KCMPNM} TO NONE FREQLIMITS 0.002 0.004 ${FHL} ${FHH}w ../${DEST}/${KSTNM}${KCMPNM}.${NET}.${LOC}.sacquitEOF

Note:• RESP used since I know units are counts/m/sec (IRIS SACPz is cts/m• File names are complete, e.g., F08ABHZ.TA..sac or F08ATABHR -

gsac << EOFr ${KSTNM}${C}?.${NET}.${LOC}.sacrotate3 to gcw ${KSTNM}${NET}${LOC}${C}R ${KSTNM}${NET}${LOC}${C}T ${KSTNM}${NET}${LOC}${C}ZquitEOF

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CWBDOROT###### high pass filter to get rid of low frequency noise#####export MODEL=${GREENDIR}/Models/AK135sph.modfor TRACE in *.sacdoGCARC=`saclhdr -GCARC $TRACE`EVDP=`saclhdr -EVDP $TRACE`DEPMAX=`saclhdr -DEPMAX $TRACE`DEPMIN=`saclhdr -DEPMIN $TRACE`A=`time96 -M ${MODEL} -P -GCARC ${GCARC} -EVDP ${EVDP}`T0=`time96 -M ${MODEL} -SH -GCARC ${GCARC} -EVDP ${EVDP}`#echo A $A T0 $T0

###### test the DEPMAX for valid amplitudes#####ANS=`echo $DEPMAX $MINAMP $MAXAMP | awk '{ if( $1 < $2) print "NO";else if($1 > $3) print "NO";else print "YES"}' `

if [ $ANS = "YES" ]then

gsac > /dev/null 2>&1 << EOFr $TRACEsynchronize ortrhp c ${FHIGH} np 2ch A ${A} T0 ${T0} T1 ${T0}whw TEMP/$TRACEquitEOF

fidone###### end of for TRACE#####

Use model to define P, S arrivals with time96

Set P S times for header

Reset reference time so can extract original time later

for documentation

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for i in *Z.*.sacdoif [ -f $i ]then echo $i

KSTNM=`saclhdr -KSTNM $i` KCMPNM=`saclhdr -KCMPNM $i` KNETWK=`saclhdr -KNETWK $i` case ${KCMPNM} in BHZ) C="BH" ;; HHZ) C="HH" ;; LHZ) C="LH" ;; esac###### safety if we do not have horizontals##### cp $i ../../${DEST}/${KSTNM}${NET}${LOC}${KCMPNM}###### now try to process the horizontals#####

gsac > /dev/null 2>&1 << EOFr ${KSTNM}${C}?.${NET}.${LOC}.sacrotate3 to gcw ${KSTNM}${NET}${LOC}${C}R ${KSTNM}${NET}${LOC}${C}T ${KSTNM}${NET}${LOC}${C}ZquitEOF

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rotate3?• Trace rotation in sac/sac2000 is a pain:

– set time marker

– synchronize

– write out

– cut

– re-read

– write out

• gsac – rotates in absolute time and outputs only the common time window

• gsac – automatically renames in terms of KSTNM, KCMPNM – do all 3 at once – no requirement for orthogonality

• gsac – one liner

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CWBDODIST

• Select stations within 500 km of the earthquake for regional source inversion. – For teleseisms, CWBDOGCARC selects

stations between 30 – 95 degrees

• Use awk and SHELL – no macros

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#!/bin/sh

###### place all traces at distances less than 500 km in the# DAT directory for waveform inversion of regional events# This assumes that the P arrival time is already set in the trace header#####DMIN=10.0DMAX=500.0###### create the DAT directory if it does not exist#####DEST=FINAL.QCif [ ! -d ${DEST} ]then mkdir ${DEST}fi

###### Go to the FINAL directory and use all data for distances <= 500 km#####

cd FINAL

for i in *[ZRT]doDIST=`saclhdr -DIST $i`ANS=`echo $DIST $DMIN $DMAX | awk '{if( $1 < $2)print "NO";else if($1 >$3)print "NO" ; else print "YES" }' `

if [ $ANS = "YES" ]thenecho $i $DIST $ANScp $i ../${DEST}fidone

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CWBDOQC

• Filter waveforms in manner used for inversion

• Quickly review all traces and click to indicate acceptability by the gsac command:– ppk q relative perplot 3– gsac sets a value in IHDR20 for wach

trace• After gsac QC, interrogate IHDR20

and move to work area:

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#!/bin/sh#set -x###### run test of bandbass filtered trace########### create the DAT.REG directory if it does not exist#####if [ ! -d ../DAT.REG ]then mkdir ../DAT.REGfi###### move to the directory for QC# then examine Z traces for P, T traces for SH and R traves for SV# Note the theoretical arrival times have already been placed into# the trace headers## we process these in the same manner as for the# waveform inversion but ONLY change the header#####cd FINAL.QC

gsac << EOF###### process all#####fileid namemarkt onxlim a -10 a 180r *sort up distrtrhp c 0.02 n 3lp c 0.10 n 3qdp 10

ppk q relative perplot 3whqEOF

Preview trace in same band used for inversion

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Mouse click sets + to indicate acceptance.IHDR20 is set positive.

This permits rapid evaluation of traces for inversion.

Note since the inversion code permits timeshifts within the window, the P time need only be approximate. So for speed, we do not manually pick the P- arrival but rather use AK135

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###### now move the selected traces to the processing area#####

for i in *[ZRT]do

IHDR20=`saclhdr -IHDR20 $i`ANS=`echo $IHDR20 | \ awk '{if( $1 < 1)print "NO";else if($1 >1)print "NO";else print "YES" }' `

if [ $ANS = "YES" ]then

echo $i $IHDR20 $ANScp $i ../../DAT.REG

fidone

Move selected traces

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Scripting

• Not tested on CYGWIN/MacOS-X– CYGWIN is Windows/MS-DOS –

commands and file system are case-insensitive. Thus no t.plt and t.Plt

– MacOS-X has similar historical artifacts

• Be careful when transferring scripts

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Frequently used programs• saccvt - convert byte order of SAC files.

NEVER mix byte orders on a platform (simpler code, FORTRAN code uses pure FORTRAN SACIO routines)

• saclhdr – list SAC header contents – used to created tables, SHELL variables

• convert (ImageMagick) – convert EPS to png for web/Word/PowerPoint

• modified rdseed

• wget

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Different Philosophy• Use modern tools

• Use the SHELL to do work rather than building into gsac

• Implement capabilities as required for effciency, e.g., ppk quality addendum to gsac

• Document and validate processing logic for implementation with other languages (rapid prototyping)

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5. Installation

http://www.eas.slu.edu/Earthquake_Center-> CPS 3.30

wget ftp://ftp.eas.slu.edu/pub/rbh/PROGRAMS.330/NP330

gunzip -c NP330.tgzcd PROGRAMS.330acroread CPSInstall.pdf

Change your PATH to point to PROGRAMS.330/bin

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rbh> cd ~/PROGRAMS.310t/PROGRAMS.330

./Setup

Checking for existence of bin and lib directories

Directory bin exists

Directory lib exists

Usage: Setup SOL WIN32 SOL-EGCS LINUX LINUX64 CYGWIN OSX

SOL SUN Solaris Compilers

SOL-GNU SUN Solaris with gcc/g77 compilers

CYGWIN CYGWIN 98/NT/2K/XP gcc/g77 Compilers

CYGWIN40 CYGWIN 98/NT/2K/XP gcc/gfortran Compilers

LINUX Linux with gcc/g77 compilers

LINUX40 Linux with gcc/gfortran compilers

LINUX64 Linux 64 bit with gcc/g77 compilers

LINUX6440 Linux 64 bit with gcc/gfortran compilers

OSX Apple with gcc/g77 compilers

OSX40 Apple with gcc/gfortran compilers

OSF DEC/Compaq ALPHA cc/f77 compilers

rbh> ./Setup LINUX

rbh> ./C

FORTRAN is clean for gfortran – 72 column, no

tabs

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rbh@shallow:~/PROGRAMS.330> ls

bin/ CPSInstall.doc DOC/ readline-5.0/ VOLII/ VOLV/ XVIG/

C* CPSInstall.pdf include/ Setup* VOLIII/ VOLVI/

CALPLOT/ CPSTEST/ IRIS/ SUBS/ VOLIV/ VOLVII/

C.proto* Csrconly* lib/ VOLI/ VOLIX/ VOLVIII/

rbh@shallow:~/PROGRAMS.330>

bin directory will have 120 programs

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6. What's New?

www.eas.slu.edu/People/RBHerrmann/CPS/cpsbug.html

Introduction

The purpose of this page is to notify users of the Computer Program in Seismology (CPS) package of repairs or extensions made to the code. Whenever this page is updated, the down loadable version of CPS is updated at the download FTP site.

Enhancements to Version 3.30 code

August 30, 2007

* gsac - implemented two new commands in prs (plotrecordsection): ScaleRelative (SR) and ScaleAbsolute power (SA Power) to control the amplitude of the traces in the record section. ScaleRelative is the old behavior which just scales each trace to the same maximum amplitude (AMP value), except that the scaling now applies only to the actual trace window and not the whole trace. ScaleAbsolute 0.0 adjusts all traces to plot true amplitude. If the non-time axis is distance, then ScaleAbsolute 1.0 adjusts for geometrical spreading by multiplying all traces by distpower . For a true refracted arrival (e.g., with no velocity gradients), power=1.5 would show the refractions at the same level. The current gsac version is now[V1.1.21 30 AUG 2007]

* wvfgrd96 is not modified so that the output traces, e.g., TRACE.obs and TRACE.pre have the time shift applied. This means that if pltsac is used with the flag -USER9 the time shift will be displayed even though the traces align. The objective here is to present the observed and predicted in such a way to focus on amplitude and phase differences and not time shifts.

August 19, 2007

* gsac - modified the write command to support 'append suffix' and 'prepend prefix'. To illustrate the differences between sac2000, we will work in a subdirectory with the files located in the level above:

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rdseed

• Modification of error output• Modification of SAC pole-zero output• Name:

SAC_PZs_NM_SLM_BHZ__1997,037,14:00:00.0000SAC_PZs_NM_SLM_BHZ__1999,160,20:40:00.0000SAC_PZs_NM_SLM_HHZ__1997,037,14:00:00.0000SAC_PZs_NM_SLM_HHZ__1999,160,20:40:00.0000SAC_PZs_NM_SLM_LHZ__1997,037,14:00:00.0000SAC_PZs_NM_SLM_LHZ__1999,160,20:40:00.0000

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Pole-zero AnnotationSAC_PZs_NM_SLM_BHZ__1999,160,20:40:00.0000

* ***** STATION (KSTNM ): SLM* COMPONENT (KCMPNM): BHZ* LOCATION (KHOLE ):* NETWORK (KNETWK): NM* START : 1999,160,20:40:00.0000* END : No Ending Time* INPUT : METERS* OUTPUT : COUNTS* ****ZEROS 3POLES 5-0.0356 -0.0369-0.0356 0.0369-251.3300 0.0000-131.0400 -467.2900-131.0400 467.2900CONSTANT 3.638452e+16

Comment permitted:* space *UnitsFile name to track response history

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7. Plans

• TI for surface-wave synthetics and inversion

• Shallow seismic processing

Work in Progress• waveform inversion, e.g., wvfmtd96,

wvfmt96

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gsac• Written from scratch (1255 .f .c in sac/

97 .c in gsac - simpler)• Modular design for commands (94, even

outcsv for excel). One source file has two parts – parse typed command line– execute command

Because of this separation the execution parameters can be trivially created by a GUI, e.g.,

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GSAC - Computer Programs in Seismology [V1.1.21 30 AUG 2007]

GSAC> r SH/115[246]/*GSAC> refr

or refr Ex or refr Reg or Refr Tel

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• Joint inversion of dispersion and first arrival times for shallow exploration?

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Obviously, there is a prs (plot record section that is not a subprocess – too inconvenient). Other trivia:

• gsac keeps trace and FFT in memory, e.g., read trace fft plotsp plot plotsp is not possible in SAC

• All system commands permitted, except those with gsac command names

•GNU readline permits command line edit, as in bash SHELL

• GNU history (without line numbers for cut/paste/repeat)

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SUMMARY: BandPass filter traces

BandPass [options]

where options is one or more of the following:

[Butter | BEssel ] [ Corner fl fh] [ Npoles npoles ] [ Passes npass]

INPUT: Butter : Butterworth filter (default) BEssel : Bessel filter Corner : Corner frequencies (R) range 0 - Nyquist Npoles : Number of poles (I) range 1 - 10 Passes : Number of passes (I) range 1 - 2

DESCRIPTION: Highpass filter using a BI-LINEAR Z-transformation implementation of a highpass filter. A bi-linear method is chosen since this is easily implemented algebraically. Passes = 1 gives a causal filter while Passes = 2 gives a zero-phase filter with a 6db point at the corner frequency.

Note: shortcuts indicated by Upper case, e.g., BP, BE – documented command short-cuts

Indented

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8. Research Needs

• Practical Earth flattening• Stable free oscillation code to 1Hz• Documented code and tutorials for

other contributions• Improve current programs through

other algorithms• Redefinition of SAC header, e.g., A, T0

are currently offsets in REAL*4 – fails for long time series

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9. User Needs

• Help– Email: rbh @ eas.slu.edu– Tutorials

• Understandable codes

• Questions?

• This presentationftp://ftp.eas.slu.edu/pub/rbh/PROGRAMS.330/cpssep2007.ppt

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Thanks

• Users asking questions

• Jim Lewkowicz and Jessie Bonner of Weston Geophysical for supporting this presentation.

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• Questions• Complaints• Needs