This is an interactive program which prompts the user as the following
dialog illustrates. The user responses are boxed.
enter: line number (4 characters)
0003
Enter: number of shots
2
Enter: minimum offset to include
40
Enter: maximum offset to include
200
Is output for refraction or direct analysis?
0=refraction 1=direct
0
irecip 0=normal 1=reciprocal shooting
0
Enter: input file name
k010.seg
Enter: input file name
k011.seg
shot x,y= 9927. 9773.
shot x,y= 9883. 9666.
Traces Processed = 48
====> output in G0003
====> listing in brefk010.lst
In the above example, the program writes 3 files, the last 4 characters
of which are the line number as specified in the dialog.
- G0003 system matrix, G, of equation (32)
- D0003 data vector, d, of equation(32)
- E0003 elevation file (3 columns; trace#, station_name,
elevation)
In general, you will have to edit the Gxxxx and Dxxxx files. The sample
data set (ID-102.zip) includes examples of these files as created
by bref (G0003.org etc.) and as modified to produce a constrained
solution (G0003.mod etc., 15 constraints). Specific files created by bref
will be highly dependent on the first break picks in the *.seg file
trace headers. The convention is to flag picks exactly equal to zero
as being unable to be picked. If none of the *.seg files has a pick
at a particular geophone station, then the problem will be singular
(unless you manually edit the file and add some rows to constrain
the solution). Bref will make an attempt to add constraint
rows to the bottom of the Gxxxx file, but they will be incomplete,
since the user must decide what to do (don't expect this code to make
critical decisions, that is your job). To replicate samples in archive, see README
file in slopeLine directory.
pm
2018-04-08