Description of the program  B P L O T

    Program BPLOT  is designed for  plotting synthetic seismogram
sections from any  file which has the same  structure as the file
LU9 generated for this purpose by programs SYNT.

Short description of the program BPLOT

    Program  BPLOT is  a modified  version of  the equally  named
program from the program package BEAM87 by V.Cerveny.
    Synthetic seismogram section is plotted  in a frame, in which
horizontal axis corresponds either to the range (if receivers are
distributed along the surface or an internal interface) or to the
depth (if  receivers are distributed  along a vertical  profile).
The vertical axis  corresponds to the travel time  or the reduced
travel  time  axis.  It  is  possible  to  use  various  forms of
amplitude scaling  along the profile, i.e.  along the x-axis. The
scaling of  amplitudes along time  axis is not  used, but may  be
simply introduced. A selection of receiver positions at which the
synthetic seismograms should be computed can be performed.

Positive polarity of impulses is to the left of vertical time axis

The components of the displacement vector into the x and y
coordinates of the model coordinate system are formally called
"radial" and "transverse" components, respectively. They are
truly radial and transverse if the profile of receivers lies
along the x-axis. By use of the angle AROT, see below, horizontal
components can be transformed into a rotated coordinate system.

Description of input and output data

    Main input data are read from the standard input by list-directed
input (free format) and consist of a single line containing following
    'LIN' 'LOU' 'LU9' 'LU4'/
    'LIN' is the name of the input data file LIN.
    'LOU' is the name of the output log file LOU.
    'LU9' is the name of the intput data file LU9,
          generated by program SYNFAN.
    'LU4' is the name of the output data file LU4.
    / is a slash recomended in batch and script files to enable future
Example of the main input data:
    'bplot.sch' /
    'bplot1.sch' 2* 'lu4x1.out' /
    'bplot2.sch' 2* 'lu4x2.out' /

    Input  data consist  partially of  the data  obtained in  the
program SYNFAN (or any other program which generates  the data in
the required form) and are stored  in the file LU9, and partially
of the  additional data  specified  by the user in the file  LIN.
Output data  describing the computations  are stored in  the file
LOU. Output data for plotting particle motion diagrams are stored
in the file LU4. The program  generates a  postscript file  with
the desired plot.

The data stored in LU9

      The data are stored in the  formatted form in the file LU9.
For details see the description of the content of the file LU9 in
program SYNT.

1) MPRINT                                FORMAT(A)
2) IPRINT                                FORMAT(A)
3) TITLE                                 FORMAT(A)
5) NDST,NT,MCOMP                         FORMAT(16I5)
6) DIST,TO,AREDUC,NT                     FORMAT(2F10.3,1E12.5,I5)
7) IS(I),I=1,NT                          FORMAT(20I4)

The additional input data in the file LIN

     These data are specified by  the user. They control plotting
of synthetic seismograms. The places, where the data from LU9 are
read in are denoted by **LU9/1, **LU9/2, etc.

1) TEXT                                          FORMAT(A)

   TEXT...    arbitrary  alphanumeric  text describing  the  data

2) Switches  which  specify the  I/O files  and which control the
   output into the file LOU.

   IPR                                           FORMAT(16I5)

    IPR...    controls the printout into the file LOU.
              IPR=0... standard print.
              IPR=1... also a table  of coordinates of receivers,
              with maximum amplitudes.
              IPR=2...  also  synthetic  seismograms,  in reduced
              For more details see the section on output tables.


3) Various switches.


    MRED...   controls the reduction of travel times.
              MRED=0... no reduction.
              MRED=1... reduction applied, see input data No.6.
    MEPIC...  controls the selection of receiver positions.
              MEPIC=0... no selection.
              MEPIC=1... selection applied, see input data No.4
    NTICX...  the  number  of  marked  intervals  along the range
              (depth)  axis  between  two  neighbouring tics with
              corresponding coordinate values.
    NTICY...  the same as NTICY, but for the travel-time axis.
    NDX,NDY...control  the  precision  of  numbers describing the
              coordinate  axes in  the plots.  NDX corresponds to
              range  axis.  NDY  corresponds  to  the travel-time
              ND.GT.0: The  number of digits to  the right of the
              decimal point.
              ND=0:  Only integer  portions of  the numbers  with
              decimal points.
              ND.LT.0:  Integers.

4) Selection of receivers positions.
   Included only when MEPIC.NE.0.

   NEPIC,(IEP(I),I=1,NEPIC)                      FORMAT(16I5)

    NEPIC...  number  of  selected  receiver  positions  at which
              synthetic seismograms are to be constructed.
    IEP(1),IEP(2)...  sequential  numbers  of  selected  receiver

    Note: Similar  selection can be  done already in  the program
    SYNT. The selection here is  made among those receivers which
    remained after the selection in program SYNT.

5) Description of axes of the plot.


    XMIN,XMAX... minimum and maximum  values along the range axis
              (in the users length units).
    XLEN...   length of the range/depth axis (in cm).
    DTICX...  the distance between two  neighbouring tics on  the
              range/depth   axis   which   are   denoted  by  the
              corresponding coordinate values (in the user length
              DTICX.GT.0.0:  Tic  marks  starting  from  XMIN and
              appearing  at  the  subsequent  points  XMIN+DTICX,
              DTICX.LT.0.0:  Tic marks  start and  continue to be
              plotted   from  the   first  integer   multiple  of
              ABS(DTICX) greater than XMIN.
    YMIN,YMAX,YLEN,DTICY...  the  same  for  the  time  axis. For
              MRED=1  (reduced  time  along  the  time axis), the
              quantities correspond to the reduced travel times.

6) Parameters of the time reduction and of the amplitude scaling
   along the range/depth axis.

   VRED,AMP,B1,EPICS,EPS,SC                      FORMAT(8F10.5)

    VRED...   reduction velocity (in km/s).
    AMP,B1,EPICS,EPS...  quantities   controlling  the  amplitude
              scaling. When  EPICS not specified,  EPICS=10. When
              B1 not specified, B1=1.
              The  scaling  factor  may  generally  depend on the
              receiver position.  Denote the x-coordinate  of the
              receiver  by XX,  and the  average distance between
              neighbouring receiver  positions by DDX  (i.e., the
              average distance between individual traces, in plot
              units). Then the following  five systems of scaling
              can be used:

              1) FACTOR=B1*DDX/SMAXI,     when AMP=0.
              Normalization of maximum amplitudes in all traces:
              For  B1=1,  the  maximum  amplitudes  in all traces
              equal  to the  average distance  between individual

              2) FACTOR=B1*DDX/SMAXIM,    when AMP=-1 and EPS=0.
              Real amplitudes: For B1=1, the maximum amplitude in
              the  whole  plot  equals  to  the  distance between
              individual traces.

              3) FACTOR=B1,               when AMP=1 and EPS=0.
              Real   amplitudes:  Manual   determination  of  the
              scaling factor by specifying B1.

              when AMP=-1. and EPS.GT.0.
              Power scaling of amplitudes: When EPICS corresponds
              to the  epicentral distance of  the trace with  the
              maximum  amplitude  and   B1=1,  then  the  maximum
              amplitude  of  the  trace  at  EPICS  equals to the
              average distance between individual traces.

              5) FACTOR=B1*(ABS(XX-XSOUR)/EPICS)**EPS,
              when AMP=1. and EPS.GT.0.
              Power scaling of amplitudes:  Fully manual, all the
              parameters must be specified.

              Note: The scaling systems 4 and 5 give for XX=XSOUR
              traces with zero amplitudes.


Example of data LIN

Termination of computations.

The data LU9/6 and LU9/7 are  read in NDST times (see **LU9/5 for
NDST). Afterwards, the computations terminate.

Output to the file LOU

    All  the  input  data  are  reproduced  in  the file LOU. The
storage  of other  data is  controlled by  the parameter IPR, see
input data No.2.
    For IPR=0, also the data LU9/1-LU9/5 are stored.
    For IPR=1, the same data as for IPR=0 are stored. In addition,
for each receiver position the following data are stored:
where XX is the coordinate of  the receiver, SMAXI is the maximum
amplitude  in   the  corresponding  seismogram,   FACTOR  is  the
amplitude  scaling  factor  corresponding  to  this receiver, and
SFMAX is the maximum amplitude  in the synthetic seismogram after
    For IPR=2,  also the synthetic  seismograms are stored.  Each
synthetic seismogram has the heading:
The quantities  XX,SMAXI,FACTOR,SFMAX have the  meaning as above.
TSTART is  the minimum time,  corresponding to the  first sample.
Synthetic  seismograms are  printed  in  a reduced  form, maximum
equals to unity.

Output to the file LU4

The file LU4 contains the computed ray synthetic seismograms
in the form required for plotting particle motion diagrams in
program POLAR. The zero samples in the initial and final parts of
each seismogram are not stored. The data are stored in the formatted
form to allow for an inspection of computations. To perform the
plotting of particle motion diagrams from the file LU4, the program
POLAR, included in this package, can be used. The data on LU4 are
stored in the following order:

1) MTEXT                                       FORMAT(17A4)
  Arbitrary alphanumeric text describing the computations. this
  text will appear under the plots. The text was specified in
  the program ANRAY.
     MMD...    the number of selected receiver positions.
     MRED...   MRED=0: non reduced travel times,
               MRED=0: reduced travel times.
     MCOMP...  MCOMP=0: vertical component,
               MCOMP=1: radial component,
               MCOMP=2: transverse component.
     ITPR...   ITPR=0: receivers along the earth's surface,
               ITPR=1: receivers along a vertical profile,
               ITPR.GT.100: receivers along the (itpr-100)th
     VRED...   reduction velocity.
     RSTEP...  average difference between coordinates of
               neighbouring receiver positions.
     XSOUR...  dummy parameter (xsour=0.).
     DT...     time step in synthetic seismogram.
3) XMX,SMAXIM                             FORMAT(22X,F10.5,E15.9)
     XMX...    coordinate of the receiver at which maximum
               amplitude smaxim was recorded.
     SMAXIM... the maximum amplitude from all stored synthetic
The following lines 4,5 are successively repeated for all receiver
positions. They contain information about individual seismograms.
Only parts of seismograms are stored, starting with the first
non-zero sample and ending with the last non-zero sample:
4) XX,SMAX,TM,NPS                    FORMAT(F10.5,E15.9,F10.5,I5)
     XX...     coordinate of the receiver on the profile
               (radius from the vertical line through the source
               for receivers along a surface or an interface
               profile, 'model' z coordinate for receivers along
               a vertical profile)
     SMAX...   maximum amplitude in the synthetic seismogram
     TM...     TM is the time corresponding to the first non-zero
               sample in the seismogram. if MRED.NE.0, TM
               is a reduced time.
     NPS...    number of points in synthetic seismograms.
5) Synthetic seismograms in normalized form:
   JS(I), I=1,NPS                              FORMAT(20I4)
     JS(I)..   I-th sample, JS(I)=IFIX(999.1*SEIS(I)/SMAX),
               where SEIS(I) is computed value of i-th non-zero

Note: The maximum length of the synthetic seismograms is 3001