OCTAVE delaytmR.m - Reciprocal shooting delay time refraction (receiver profiles)
delaytmR prompts for:
System matrix
file, Data file, Elevation file, Water Depth file (GUI Entry
Box)
Number of receivers on shore (for reverse profiles, should
be some on both banks. (GUI Entry Box)
Smoothnes Weight 0<W<1 (the larger W, the poorer the
data fit) (GUI Entry Box)
GUI Pop Up Box, Solution for refractor velocity and receiver
delay times on shore (Click OK)
Plot of shot delay times across river
Entry box for overburden velocity (GUI Entry Box)
Plot resolving delay times to structure of refractor.
Layers: water,overburden, refractor
Entry box for a constant river bottom to refractor
alternative (GUI Entry Box)
Plot resolving delay times as velocity of overburden
Entry box for number of constraint equations in system
matrix (GUI Entry Box)
Plot showing fit of first breaks for each receiver-shot
profile
Basic Seismic Utilities (BSU) program run in Octave or Matlab. This is the reciprocal of normal refraction shooting designed for profiles across rivers. Shot positions are deployed across the river, as from a bridge, and correspond to geophones on a conventional refraction profile. On the shore are receiver positions, typically fewer than the number shots. Inputs to delaytmR.m include files generated by program bref. Also required is a water depth file. It gives the depth below each shot point to the river bottom. The format is (depth, shot station number) pairs, one for each row in the file. The structure of the system matrix file is receiver columns followed by shot columns followed by the receiver-shot distance column on the far right. Within an octave session, type delaytmR and a GUI entry box will pop up with the names of 4 files to process. These include a system matrix (G001), a data vector with observed first arrivals (D001), an elevations file (E001), and a water depth file (wds.dat). Additional prompts as shown above. For conventional refraction delay time analysis see delaytm.m.
Message box of
receiver delay times on shore
Plot of shot delay times across river
Plot of refractor structure below river bottom and surface.
(delay times --> structure)
Alternative Plot of overburden velocity variation across
river. (delay times --> overburden velocity)
Plot of shot stations and observed first arrival times with
solid lines predicted by solution.
G001 system
matrix (or some other name, depends on line number entered
into bref)
First columns are receivers on shore, then shot columns,
finished by offset column
May include constraint rows at bottom.
D001 observed data (first break, shot station) pairs plus
any constraints at bottom.
E001 (shot number, shot station, elevation) triplets
wds.dat (water depth, shot station pairs)
bpic(1) bref(1) OCTAVE: segyinfo.m(7) bsegin.m(7) segpic.m(7) delaytm.m(7) direct.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>