Tutorial for the installation, running and visulaisation of the sample location problem.
Overview - Installing the sample location - Running the sample location tutorial - [NonLinLoc Home]
The following steps will lead you through the installation of files, the creation of a model grid and calculation of travel time grids, and the location and visualisation of the sample location.
Before doing the sample location, you must download and install the NonLinLoc software, and, for visualisation, the Seismogram Viewer software (see the NonLinLoc Home page). For postscript plotting, you need to have the the GMT plotting package available on your system. (Note that the sample location tar include a hidden ".gmtdefaults" file that will be installed in your sample location working directory. You may want to modify this file, but for proper functioning of Grid2GMT leave the units as "MEASURE_UNIT = cm")
Copies of some the output files you should obtain will be in the original_output/
sub-directory of the directory where you install the sample location
files.
mkdir $HOME/NLLoc
Copy the samples tar file to this directory, i.e.:
cp $HOME/download/NLLVersion_samples.tar.gz
$HOME/NLLoc
where: Version is the NNloc version you
are using (i.e. NLLoc1.30_samples.tar.gz).
Go to the working directory, i.e.:
cd $HOME/NLLoc
Unzip and unpack the files:
gunzip NLLVersion_samples.tar.gz
tar -xvf NLLVersion_samples.tar
This will create the directory nlloc_sample/
with sub-directories:
data_geog/ loc/ obs/
run/ viewer/
gmt/ model/ original_output/
time/
and a hidden .gmtdefaults file.
Examine the NonLinLoc Control file: run/nlloc_sample.in,
this file contains the statements used by each of the NonLinLoc
programs when the sample is run.
cd
$HOME/NLLoc/nlloc_sample
Generate and view the model grid
Create the model grid:
Vel2Grid
run/nlloc_sample.in
Create a GMT script and postscript image of the model:
Grid2GMT
run/nlloc_sample.in model/layer.P.mod gmt/ V G 1 0 1 301
Look at the postscript with your favorite viewer, i.e.:
gs
gmt/layer.P.mod.VG.ps
Generate and view the travel-time and take-off angle grids
Create the travel-time and take-off angle grids:
Grid2Time
run/nlloc_sample.in
Create a GMT script and postscript image of a travel-time grid:
Grid2GMT
run/nlloc_sample.in time/layer.P.AURF.time gmt/ V G 0 0 0 301
Look at the postscript with your favorite viewer, i.e.:
gs
gmt/layer.P.AURF.time.VG.ps
Create a GMT script and postscript image of a take-off angle grid:
Grid2GMT
run/nlloc_sample.in time/layer.P.AURF.angle gmt/ V G 0 0 0 301
Look at the postscript with your favorite viewer, i.e.:
gs
gmt/layer.P.AURF.angle.VG.ps
Generate some synthetic arrival times
Create the synthetic times:
Time2EQ
run/nlloc_sample.in
Look at the synthetic times:
more obs/synth.obs
Do the event Location
Locate the event using the Oct-Tree search:
NLLoc
run/nlloc_sample.in
Look at the NonLinLoc Hypocenter-Phase location file:
more
loc/vinti.19950421.080259.grid0.loc.hyp
Plot the first event location with GMT
Create a GMT script and postscript image of the location PDF:
Grid2GMT
run/nlloc_sample.in loc/vinti.19950421.080259.grid0.loc gmt/ L S
Look at the postscript with your favorite viewer, i.e.:
gs
gmt/vinti.19950421.080259.grid0.loc.LS.ps
Combine all event locations with LocSum
Combine the Hypocenter-Phase and scatter files into a location summary file:
LocSum ./run/vinti 1
loc/vinti "loc/vinti.*.*.grid0.loc"
Plot the combined locations with GMT
Create a GMT script and postscript image of the location Expectations and Ellipsoids:
Grid2GMT
run/nlloc_sample.in loc/vinti gmt/ L E101
Look at the postscript with your favorite viewer, i.e.:
gs
gmt/vinti.LE_101.ps
Visualise the location with Seismicity Viewer (you must have installed Seismicity Viewer, see Seismicity Viewer software guide)
Go to the viewer directory, i.e.:
cd
$HOME/NLLoc/nlloc_sample/viewer
Run Seismicity Viewer and visualise interactively the combined locations:
java
seismicity.Seismicity ../loc/vinti.hyp
Back to the NonLinLoc site Home page.
Anthony Lomax