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
LU8 generated for this purpose by programs SYNFAN.

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  horizontal
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.

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' 'LU8' 'LU4'/
    'LIN' is the name of the input data file LIN.
    'LOU' is the name of the output log file LOU.
    'LU8' is the name of the intput data file LU8,
          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
    'bplot.ani' /
    'bplot.qi' /

    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 LU8, and partially
of the  additional input  data  read by list-directed input (free 
format), 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 

The data stored in LU8

    The data are stored in a formatted form in the file LU8. For 
details  see  the  description of the content of the file LU8 in
program SYNFAN.

1) MPRINT                                FORMAT(A)
2) IPRINT                                FORMAT(A)
3) TITLE                                 FORMAT(A)
5) NDST,NT,MCOMP,ILOC                    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 LU8 are
read in are denoted by **LU8/1, **LU8/2, etc.


   TEXT...    arbitrary  alphanumeric  text describing  the  data
              set. Default 'BPLOT'

2) Switch, which controls the output into the file LOU and optional
   name of the plot file.


    IPR...    controls the printout into the file LOU and the type
              of the name of the postscript file with a plot.
              IPR.GE.0... automatic generation of postscript file
              names:,, etc.
              IPR.LT.0... postscript file name specified by the user,
              see PSTEXT.
              IPR=0... standard print (default value).
              IABS(IPR)=1... also a table of coordinates of receivers,
              with maximum amplitudes.
              IABS(IPR)=2...  also  synthetic  seismograms,  in reduced
              For more details see the section on output tables.
    PSTEXT... the name of the postscript file specified by the user;
              it is used only if IPR.LT.0.


3) Various switches.


    MRED...   controls the reduction of travel times.
              MRED=0... no reduction (default value).
              MRED=1... reduction applied, see input data No.6.
    MEPIC...  controls the selection of receiver positions.
              MEPIC=0... no selection (default value).
              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 (default value 1).
    NTICY...  the same as NTICY, but for the travel-time axis 
              (default value 1).
    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 (default value).
              ND.LT.0:  Integers.

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


    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
    SYNFAN.  The selection here  is made  among  receivers, which
    remained after the selection in program SYNFAN.

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...   reduction velocity (in km/s) default VRED=6.0.
    AMP,B1,EPICS,EPS...  quantities   controlling  the  amplitude
              scaling. Default values 0., 1., 10. and 0., respectively.
              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.

    SC...     scaling factor, controls scaling of tics and
              alphanumeric texts. For SC=1.0, the tics are 0.15 
              cm long and coordinates and text describing the 
              plot are 0.4 and 0.45 cm high, respectively.


Example of data LIN for anisotropic model
Example of data LIN for isotropic model for QI computations

Termination of computations.

The data LU8/6 and LU8/7 are  read in NDST times (see **LU8/5 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 line No.2.
    For IPR=0, also the data LU8/1-LU8/5 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(A)
  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: component along the x-axis,
               MCOMP=2: component along the y-axis.
     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, YSOUR...  x- and y-coordinates of the source.
     DT...     time step in synthetic seismogram.
3) XMX,SMAXIM                             FORMAT(22X,F10.5,9X,F15.9)
     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,E15.8,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