The
dialogue that appears on activating the program asks about the following
parameters. Enter appropriate values according to the instructions written in
red.
Data directory name
[demo/synth_SN100_18mGamR0.8RV0.1N6] >
Enter the
name of the folder where the data files are stored. Separate the folder path
with slashes (/).
* Execution parameters
Do spectral analysis
[e.g., Calculate phase velocities and other properties of surface waves]?
(y/n=1/0) [1] Set this option to 1 to execute spectral analysis and
phase velocity analysis.
Preprocess the data? [This
includes elimination of the trend (including subtraction of the mean as a
special case), application of tapers, bandpass
filtering, decimation and correction for differences in instrumental response]
(y/n=1/0) [0] Set this
option to 1 to execute the data preprocessing.
Automatically select data
portions to be used? (y/n=1/0)[1] Setting this
option to 1 means that data portions to be used in the estimation of spectra
are selected automatically from the waveform data (click here for the algorithm of automatic selection) and that a
segment file is generated (click
here for the segment file names and their format). Create a
segment file on your own and set this option to 0 if you wish to make your own
selection of the portions of the waveform to be used in the analysis.
Delete temporary data
files? (y/n=1/0)[0] Setting this option to 1 ensures that all
intermediary data, generated on the way, are deleted when the data processing
is over, except for the final analysis results and a small number of input
files and log files. Setting this to 0 allows all intermediary data to be
preserved.
Plot analysis results?
(y/n=1/0)[1] Set this option to 1 to plot the analysis
results.
* Basic parameters
Take a look at Estimating Spectral Densities and A Knack for Setting
Parameters before proceeding to enter
the following parameters.
Duration of data segments
for the evaluation of spectra [s] [10.24] The segment duration [seconds] used in
the estimation of spectra (segment averaging method). When the number of data
points, calculated by (segment duration) / (sampling time interval), is not
equal to a power of two, it is automatically zero-padded to a power of two
during FFT (for the sake of efficiency, it is recommendable to adjust values to
produce a power of two).
Number of data segments
over which averages are taken. Enter 0 or a very large number if you wish to
use all segments simultaneously [10]
The number of segments (integer) used in the
estimation of spectra (segment averaging method). Entering a large integer,
which exceeds the total number of segments catalogued in the segment file, or
zero means "segment averaging using a single segment (virtually no segment
averaging)."
Band width of the Parzen spectral window [Hz] [0.3] The width of the spectral (Parzen) window [Hz] used in the estimation of spectra
(smoothing method). Entering zero means "a zero window width (virtually no
use of a spectral window)."
* Data file and array
geometry
A preexisting seismfile demo/synth_SN100_18mGamR0.8RV0.1/seism.d (for the data file names and the array geometry)
has been detected. Prescribe the array geometry, waveform
components and the sampling time interval in \(data folder)\seism.d.
When no file is found under this name, interactive questions generate one
automatically.
----------------citation
begins here-------------------
#COMP 3 (1 ud / 2 ns
& ew / 3 three components) Enter the waveform components (type 1, 2
or 3 following a space or a tab after #COMP).
#DT 0.01 Enter the time interval of waveform
sampling (type a figure following a space or a tab after #DT).
0.000000 0.000000 S01.d 1 From left to right, the x coordinate
[km], y coordinate [km], data file name, and integer 1 or 0 (1 if center).
0.000001 0.018000 S02.d 0
0.017119 0.005562 S03.d 0
0.010581 -0.014562 S04.d 0
-0.010579 -0.014563 S05.d 0
-0.017119 0.005564 S06.d 0
Notes
(*1) Appending "#"
at the head of a line comments that line out (except for #COMP and #DT). There
is no rule on the order of arrangement of these data. There is no special
format for the numbers.
(*2) When only two sensors constitute
the array, think of either one of them as being at the center and the other as
lying around the circle, and accordingly assign them integers of 1 and 0 to the
right of the data file names.
(*3) When there is only one
sensor constituting the array, the integer to the right of the data file name
can be either 0 or 1 (the H/V spectrum alone is calculated, and there will be
no array processing).
(*4) When the records have
three components (#COMP 3), the H/V spectrum is calculated using the file indicated
in the top data line.