Refraction traveltime tomography GUI interface for Matlab 5
By Min Zhou, University of Utah.
Installation
DSI Data format
Online documentation
Feedback
Process the refraction data in the same interface, from data loading, preprocing, and first arrival picking, to
inverting. It makes use of the convenience of matrix operation and graphic functions of MATLAB. We use the public released DSIoft package for data converting, picking, filtering and displaying.
Installation
First, please download the files:
The codes can run in Unix/Linux/PC with Matlab 5.0 or higher version. All the Matlab files and Fortran codes are stored in directory 'openfile' (you can change the directory name), since the Matlab 'startup.m' can only set path for Matlab M files, all executable Fortran codes and their input data files should be put into current work directory.
There are several subdirctories in 'openfile':
| aspec: |
Matlab files for display spectrum (DSI software), |
| demos: |
DSI demos(DSI software), |
| display: |
Matlab functions for displaying DSI format data(DSI software), |
| fkfilter: |
Matlab functions for f-k filter(DSI software), |
| fortran: |
Fortran source codes |
| inverse: |
Matlab function for forward modeling and inversion |
| m: |
My current work directory |
| main: |
Matlab functions from DSI(DSI software), |
| picker: |
Matlab functions for picking(DSI software), |
| plotheaders: |
Matlab functions for displaying header information(DSI software), |
| qc: |
Matlab functions for quality controll |
During installation, after you have copied all the files into your computer,
Three things must be done before you can start the work:
- Go to 'openfile', edit the file 'startup.m', set search path for this directory in second line which shows 'workdir=...'.
- Go to subdirectory 'fortran', find the batch file 'forrun', change the Fortran compile command which is for your computer. If you can not run 'forrun',
compile all the fortran codes and copy the executable codes to the work directory, i.e. subdirectory 'm'.
- Go to subdirctory 'main', find Matlab file 'segy2dsi.m', edit the line:
[dataout]=segy2mat(fopen,'crosswire.crs','b');
The last parameter 'b' indicates the endian of the input SEG-Y file, you should edit it according to your SEG-Y file format, though SEG-Y files from the field tape are usually in big endian, you should make sure of it because it might have been changed.
| 'b' for big endian (SUN unix files) |
| 'l' for little endian (PC linux files) |
- There is a fortran code which converts fortran unformatted data format to the Matlab .MAT format in order to display data/results in Matlab. In your work directory 'm', you can find two executable files:
't4_sun' and 't4_pc'.
Copy one of them to your work directory with the name 't4':
| t4_sun | ----> t4 | for big endian machines (SUN) |
| t4_pc | ----> t4 | for little endian machines (PC) |
|
We have fortran source code for 't4_pc', while only have executable code for 't4_sun'. They are both in the directory 'fortran'.
DSI Data format
In order to proceed with software development, a variable protocol first had to be decided on. MATLAB works most efficiently on matrices, which are required to be rectangular, but it also supports cell arrays and structured variables, which have no symmetry requirements and can contain other matrices, cell arrays or structured variables within themselves. The DSI variable format is a mixture of the three variable types mentioned above. It is a structured variable with a .fh extension for the file header, a .th extension for the trace headers, and a .dat extension for the seismic traces. Please refer to DSIoft package for the detailed list of header word numbers and meanings.
Online documentation
1. Interfaces and files
The Interface consists of nine main parts(buttons):
A. Load Data
B. Display Data
C. Preprocess Data
D. Pick data
E. QC Data
F. Invert Data
G. Forward Modeling
H. Documentation
I . Quit GUI
2. Interactive modules
| aspec |
shows plots of amplitude and phase vs. frequency (screenshot) |
| dispseis |
display module for looking at seismic traces (screenshot) |
| fkpoly |
plots the {f--k} spectrum of seismic traces and allows interactive
picking of a polygon to be used for f-k filtering with options to
look at filtered results of passing or rejecting contents of polygon (screenshot) |
| pick1comp |
interactive first break picking on one component with options to tune,
kill traces, and flatten according to pick times (screenshot) |
| pickfb |
interactive first break picking simultaneously on 3 components with
options to tune according to component with most energy, kill traces, flatten
according to pick times, and rotate components on the fly (screenshot) |
| plothd |
plots contents of trace headers in 2 or 3 dimensions as selected from
a menu that identifies the significance of each trace header word (screenshot) |
Feedback
We would like to hear from you, please send us emails: mzhou@mines.utah.edu
