Go to the list of seismic processes.
Go to SIOSEIS introduction.
SIOSEIS LANGUAGE AND LANGUAGE SYNTAX
DOCUMENT DATE: January 1988, updated March 1997
SIOSEIS applies seismic processes in the order specified via the PROCS
command (see the PROCS document for the list of processes available).
The list of processes must start with an "input" process and terminate
with an "output" process. As with all SIOSEIS parameters, each process
name in the PROCS list must be separated by at least one blank and must
be terminated with the word END. The PROCS list should be the first
thing given to SIOSEIS mainly because it clearly documents what the job
is doing. e.g. procs input filter agc plot end
It is usually simplest to run SIOSEIS out of a command file or shell
script, where the first line or lines are the operating system commands
to execute the program. So, the command file might look like:
SIOSEIS << eof
procs input filter agc plot end
which would execute the program SIOSEIS and process the data in the order
specified.
SIOSEIS must be told to stop reading from the command file by terminating
the command file with the word END.
SIOSEIS << eof
procs input filter agc plot end
end
*** SIOSEIS is case insensitive, i.e. either upper or lower or both
cases may be used.
*** SIOSEIS uses a line length of 200 characters.
*** SIOSEIS uses a blank or tab as delimiters to separate variables.
*** Multiple consecutive blanks are treated the same as a single blank.
The variables or parameters for each process described in the PROCS list
must be specified before the final END. The parameters for each process
must start with the name of the process and must terminate with the word
END. For clarity, it is wise to start and end with separate lines.
e.g. SIOSEIS << eof
procs input filter agc plot end
input
end
filter
end
agc
end
plot
end
end
The order in which the process parameters appear doesn't matter, e.g.
SIOSEIS << eof
procs input filter agc plot end
input
end
plot
end
agc
end
filter
end
end
The variables for each process are given in parameter lists governing a
set of shots (or rps). Each parameter list must be terminated by the
word END. A parameter list is similar to a "FOR loop" in many other
computer languages, but SIOSEIS has preset values for the initial loop
value (SIOSEIS parameter name FNO) and the terminal loop vaule (LNO). e.g.
SIOSEIS << eof
procs input filter agc plot end
input
end
end
filter
end
end
agc
end
end
plot
end
end
end
The individual parameters are always a parameter name followed by a value,
where the value may be a number or a group of letters.
e.g fis 1 addwb yes
The parameters within each parameter list apply to all shots/rps within
a first/last set. e.g FNO 101 LNO 200 pass 10 100 end
means shot 101 through shot 200 will have that same filter passband.
SIOSEIS assumes that shot numbers are monotonically increasing.
i.e. each shot number must be larger that the previous shot number.
Multiple parameter lists may given in order to change parameter values
on different shots. Using the "FOR" loop mentioned above, SIOSEIS permits
many loops within each process's parameters (nested loops are NOT permitted).
e.g. nmo
FNO 100 vtp 2000 5 2200 6.0 2600 6.7 end
FNO 110 vtp 1950 5.1 2250 6.1 2620 6.8 end
end
describes different velocity functions for shot 100 and 110.
*** The order in which parameters within each list is not important.
e.g. fis 1 lis 5 is the same as lis 5 fis 1
*** Parameters and values must be separated by at least one blank or tab.
*** A single parameter list may be on more than one line.
*** Every parameter list must be terminated with the word END.
*** A single parameter line may not contain more than 200 characters.
*** Most parameters have default or preset values and do not have to be
given unless the value needs to be changed. A default value is
reset to the program value on each parameter list, whereas a preset
value does not change from list to list unless reset by the user.
*** SIOSEIS converts parameter values to the proper type so that decimal
points on whole numbers are irrelevant.
e.g. values 1 = 1. = 1.0 = 1.00
*** A duplicate parameter (mistakenly given twice in the same list) is
not an error; the value associated with the last one is used.
*** In line comments are useful to document the SIOSEIS job. A
parameter line is terminated by the normal carriage return or by
the characters !, {, or #. Anything after these characters will be
ignored.
e.g In order to skip a shot on tape, multiple INPUT parameter lists are used.
i.e. Use multiple "FOR" loops, with each loop terminated with END.
SIOSEIS << eof
procs input filter agc plot end
input
fis 1 lis 10 iunit 1 end
fis 12 lis 20 end
end
filter
pass 20 80 end
end
agc # this is a comment
winlen .5 end ! anything after !, {, # is ignored
end
plot
end
end
end
It is often convenient to spatially vary a parameter between shots/rps.
The shots/rps on which the user defines the parameter may be called a
"control point". Shots/rps between control points will receive
parameters that are interpolated values of the control points, based on
the number of shots/rps between the control points and the current shot.
Shots/rps outside ALL controls points will receive parameters that are
held constant from the end control points.
e.g. In order to vary the velocity function along the seismic line, the
velocity function (parameter VTP) is given at defined rps.
nmo
FNO 10 vtp 1450 4.5 2200 9.0 end
FNO 20 vtp 1400 4.0 2200 9.0 end
end
In this case, rps 1-10 will receive the vtp associated with rp 10.
Rps 11-19 receive interpolated velocity functions based on the distance
the rp is from rp 10 and rp 20. Rps 20 and larger get the velocity
defined at rp 20.
Go to the list of seismic processes.
Go to SIOSEIS introduction.