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.
Description of input and output data
Input data consist partially of the data obtained in the
program SYNT (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. Specification of the files LIN, LOU and LU9 can be made
through the routine SERV, which is part of this program package.
If the routine SERV is not used (put 'C' in front of 'CALL SERV'
in the beginning of the main program), the files LIN and LOU are
automatically specified LIN=5, LOU=6, the file with plot has
number 7 and the number LU9 is read from the file LIN, see below.
Program BPLOT generates a plot of a synthetic seismogram section.
It uses the CALCOMP routines PLOTS, PLOT, SYMBOL and NUMBER.
These routines are not included in the package, but must be
linked with BPLOT.
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)
4) XSOUR,YSOUR,ZSOUR,TSOUR,RSTEP,DT,DF FORMAT(5F10.5,2E15.7)
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
set.
2) Switches which specify the I/O files and which control the
output into the file LOU.
LU9,LU10,IPR FORMAT(16I5)
LU9... the number of the file in which ray synthetic
seismograms are stored. It has no meaning if
routine SERV is used.
LU10... the number of the file in which data are stored for
further use in the program POLAR for plotting
particle motion diagrams. It has no meaning if
routine SERV is used.
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
form.
For more details see the section on output tables.
**LU9/1
**LU9/2
**LU9/3
**LU9/4
**LU9/5
3) Various switches.
MRED,MEPIC,NTICX,NTICY,NDX,NDY FORMAT(16I5)
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
axis.
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
positions.
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,XLEN,DTICX,YMIN,YMAX,YLEN,DTICY FORMAT(8F10.5)
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
units).
DTICX.GT.0.0: Tic marks starting from XMIN and
appearing at the subsequent points XMIN+DTICX,
XMIN+2.0*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
traces.
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.
4) FACTOR=B1*DDX*((ABS(XX-XSOUR)/EPICS)**EPS)/SMAXIM
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.
**LU9/6
**LU9/7
The data LU9/6 and LU9/7 are read in NDST times (see **LU9/5 for
NDST).
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:
XX,SMAXI,FACTOR,SFMAX,
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
scaling.
For IPR=2, also the synthetic seismograms are stored. Each
synthetic seismogram has the heading:
XX,TSTART,SMAXI,FACTOR,SFMAX.
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.