21.5 PLOTSPEC

The program PLOTSPEC is plotting of spectra generated by AUTOMAG.

The command AM in EEV automatically generates the spectra for the corresponding event and read the maximum WA amplitudes. The automatic obtained parameters, within the error limits defined in AUTOMAG, are then saved in the S-file. In some cases, both the automatic spectral analysis and the automatic amplitude can fail. The spectra most often fail because the automatically determined frequency interval has been wrongly selected. The automatic amplitude can fail if the signal to noise ratio is high so amplitudes are determine in the noise. Manual analysis of course spot these problems at once but for the automatic analysis it is hard to judge if a deviating magnitude is real or caused by wrong analysis. PLOTSPEC can therefore plot all the accepted results for the automatic analysis for one event and it is easy to judge the results (see Figure 21.2). Determinations considered in error can then be deleted on the plot and will, when finishing the program, also be deleted in the S-file. The command in EEV to plot is PS.

Program operation

AUTOMAG generates a series of output files intended for plotting with names like BKS.BH_Z.noise, BKS.BH_Z.obs, BKS.BH_Z.synth. The station and component information for all accepted determinations are stored in the file AUTOMAG.list, see example below showing entries for the first 5 channels in Figure 21.2:

1996  625 0337 31.1 L  61.687   3.283 15.0  TES 31 2.0 3.3LTES 3.0CTES 3.2LNAO
FOO  S  Z
Ml=3.4 A=  1425 T=0.24
f= 0.09-20.00
Mw=3.5
 1996  625 0337 31.1 L  61.687   3.283 15.0  TES 31 2.0 3.3LTES 3.0CTES 3.2LNAO
SUE  S  Z
Ml=3.4 A=  1094 T=0.20
f= 0.49-20.00
Mw=3.3
 1996  625 0337 31.1 L  61.687   3.283 15.0  TES 31 2.0 3.3LTES 3.0CTES 3.2LNAO
OSG  S  Z
Ml=3.5 A=   941 T=3.58


 1996  625 0337 31.1 L  61.687   3.283 15.0  TES 31 2.0 3.3LTES 3.0CTES 3.2LNAO
HYA  S  Z
Ml=3.8 A=  1146 T=0.32
f= 0.09-20.00
Mw=3.6

f= 1.82-20.00
Mw=3.2

The first line is the header line from the S-file so it does not reflect the magnitudes calculated automatically until an update has been made. Second line is the station and component. Third line is local magnitude and corresponding amplitude (nm) and period(s). Fourth line the frequency interval used for the spectral fitting and the fifth line the moment magnitude. Values that could not be determined are left blank.

The plot has room for 15 pairs of spectra/WA traces. The fitted spectrum is plotted in red and for the WA trace, the trace between the two extremes used for the amplitude observation, is plotted in red. If either the spectrum or the WA-trace is not used for a particular component, the corresponding part of the plot is left blank. If there are more then 15 component plots, several pages can be plotted.

To delete a value, put the cursor in the corresponding plot square and press d. A diagonal line will appear in plot to indicate that a value is to be deleted. When terminating the program, the user will have to confirm the delete of all. There is no undelete option for single channels.

NOTE. Both spectral information and WA amplitudes can be deleted from the s-file with command DELS.

Figure 21.2: Plot using program PLOTSEC. The WA amplitude for OSG and spectral estimate for LOF have been deleted. The automatic fits are plotted in red. This event is found in the TEST_ database.

PLOTSPEC is intended to be used from EEV but it will also work outside EEV by giving command PLOTSPEC. The program will then look for the latest AUTOMAG.list in working directory and plot spectra for the FIRST event ONLY. If AUTOMAG has been used with many events, some of the results for the first event might have been overwritten if the same STAT-COMP is used in several events and will not be plotted. PLOTSPEC has one optional argument which is the S-file to use.