SIA Job description

Seismic processing flows are described in ASCII files formatted as  spreadsheets. 10 parameters per line (including key words, module and list names) are allowed. The parameters are separated by tabs, but equivalent number of spaces (usually 8) can be used, although not recommended.  Formats of the parameters and their semantics can be obtained from the on-line documentation.

All module parameters are arranged in "lists". The "global" list immediately follows the name of the module; other lists have names appearing in the first field of the corresponding line of the job description file. Each list may be followed by an arbitrary number of "repeat" groups of parameters.

All key words begin with an asterisk '*'. The key words defined at present are:

**,#
Commentary line.
'**' must be put at the beginning of the line; '#' begins a commentary at an arbitrary position in the line.
*call, *run Includes a module into the processing flow.
*define, *undef Preprocessor directives: symbolic substitutions.
*info Calls module info displaying the self-documentation of the job.
*incl Directive to include another file into the job description.
*job In the present version, does nothing.  In future, will load the appropriate suite of databases (project, area, line, user) associated with the current task
*flush Tempoararyly forces EOF phase causing flushing of all the traces that have been accumulated up to this point
*end Consumes all the traces.  This allows to string several trace processing flows in one job (for example, in order to utilize joint modifications of the database tables)
*info Prints a message during execution (optionally including time or curent values of parameters)
*loop, *back Arrange a loop in the processing flow (that is, actually send the traces along a loop!)
*repeat, *endrep Repeat a group of traces or ensembles
*if, *elseif, *endif Conditional trace handling
*start, *close Perform UNIX operations before  Process Phase and after EOF Phase, respectively
*nocall, *comm Deactivates the module. Module used with a *nocall key word is not called neither in Edit, nor in Process phase, but its parameters may be still present on the job.
Note! At present, the parser is not able to distinguish parameter list from a text line in a REPEAT group, if the line begins with the name of the list. Occasionally, this may lead to a confusion. The solution is to avoid list names in first positions of such text lines.

An example of a processing flow description used in our polarization filtering of 1992 Kola VSP records is presented below.

*info
	This job reads syncronously two files with X,Z components 
	and performs P/SV wave separation
	##########################################################

# first define plot file names and some constants
#################################################
*define psfile  FIGURES/VSP/psv.ps	# output PostScript file 
*define	lastdp  6000            	# last depth level to read in and process 
*define	lfz     4700            	# end of the first window 

*call	dskrd           	# synchronous input of data from two files 
range	depth   lastdp /transient3/morozov/k2-rotated-1.sia 
synchro	depth   normal  chan    normal

*call	dskrd   range   depth   lastdp  /transient3/morozov/k2-rotated-2.sia
synchro	depth  normal  chan    normal

*call	filter                  # trapezoidal band-pass filter
polygon	general 10      0       20      1       50      1       70      0

*call	hdrmath 		# assign the velocities within the depth windows 
set	vp	float   6.6
condset	depth   lfz     vp      float   5.9
set	vs      float   .57735 vp

*call	psvfilt 201     depth   chan    1       2       # P/SV polarization filter 
scheme	direct  vsp     .15
break	depth   lfz     pad     20      vel     vp      vs
output	11      12      # P and SV components are stored as chan 11 and 12 

*if            # write two of the filtered gathers into two files and plot
list	chan    11      12 

*call	write                    # module write can write traces selectively 
select	chan    1       1       /transient3/morozov/k2-psvfilt-11.sia
VSP 2, P-wave component (chan 11)      # ASCII file header

select	chan    12      12      /transient3/morozov/k2-psvfilt-12.sia
VSP 2, SV-wave component (chan 12)     # ASCII file header

*call	sort            	# sort before plotting
major chan 
minor depth 

*incl	plot-xyz-2.inc 		# include file containing plotting commands
				# (not shown here) 

*endif				# end of *if statement 

Copyright (c) 1995-1999, I. B. Morozov, Rice University and University of Wyoming
This document updated Sept, 28 1999.