OCTAVE direct.m - Determination of overburden velocity by direct arrivals
direct prompts for:
System matrix
file, Data file, Elevation file (GUI Entry Box)
Number of shots (GUI Entry Box)
Basic Seismic Utilities (BSU) program run in Octave or Matlab. Within an octave session, type direct and a GUI entry box will pop up with the names of 3 files to process. These include a system matrix (G001), a data vector with observed first arrivals (D001), an elevations file (E001). You may need to change these file names depending on line number used in bref. Next a GUI entry box will ask for the number of shot profiles. It is assumed that the bref run selected a range of near offsets where direct waves are likely to arrive before refracted arrivals. More than one shot gather can be processed simultaneously to obtain a best fit to the overburden velocity. Run direct.m before delaytm.m so that an estimate of overburden velocity is available when doing the refraction problem.
Plot of direct
arrivals and the solution. Title of the plot has overbureden
velocity with 95%
confidence limits.
G001 system
matrix (or some other name, depends on line number entered
into bref)
First columns are shots, followed by receiver columns.
D001 observed data (first break, receiver station) pairs
plus any constraints at bottom.
E001 (receiver number, receiver station, elevation)
triplets
bpic(1) bref(1) OCTAVE: segyinfo.m(7) bsegin.m(7) segpic.m(7) delaytmR.m(7) delaytm.m(7)
No known bugs.
Copyright © 2017 by Paul Michaels
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
P. Michaels, PE. <pm@cgiss.boisestate.edu>