Calibrating the SNSN seismometer "ONA" against the SCG:
cal-zacc10Hz-SCG
USAGE:
cal-zacc10Hz-SCG [options] [YYMMDD [HH]]
on Holt to be run
from cd /home/hgs/Seismo/gcf
with path (tcsh):
set
path = ( . /home/hgs/Seism/sac/bin /home/hgs/Seism/bin
/home/hgs/bin \
/home/hgs/perlproc /opt/absoft11.5/bin /usr/local/GMT/bin \
/usr/local/sbin /usr/local/bin /usr/sbin /usr/bin /sbin /bin )
PURPOSE:
Calibrate
the Guralp seismometer against the SCG
from three
hours of 10 Sps ("Hz") vertical acceleration data ("ZACC").
YYMMDD
and HH are the start date and hour.
(Specify
date in short and tight form!) Default is
midnight two
days before today.
More thorough
analysis compared with cal-seis
Advantageous
selection of date and time:
If there is a teleseismic event
with surface waves of
roughly the same order of
magnitude as the microseismic noise.
This will turn out a balanced
wide-band average of the scale
factor. How flat
is the Guralp's gain spectrum? Inspect the plot!
Check out
microseismics in
http://barre.oso.chalmers.se/hgs/SCG/memspectro.html ,
our short notes
from USGS
http://barre.oso.chalmers.se/hgs/SCG/ens-eqtimes-daily-upd.html ,
and daily
residuals
http://barre.oso.chalmers.se/hgs/SCG/daily-residual-plots.html
all from our SCG.
In order
to analyse once the data processing is complete,
issue
fgrep 'Norm.CHI^2' tmp/tmp?*.fit
e.g =>
find a minimum in segment 01
fgrep '(admit)' tmp/tmp-01.fit
e.g. =>
admit = 1.0653 => next time,
calc "27.504 * 1.0653" = 29.300
=>
gcf2ts-hourly -cal 29.300 would be better
Actually, the later version of the script creates a quite useful
report,
including chi2,
admit, a residual slope, and the scale factor w.r.t. to the
measurement
unit of the Guralp's ADC "counts".
Read the
report:
cat logs/cal-zacc10Hz-SCG-YYMMDD-HH-lag0.rep
and find
e.g. the highest x-correlation at lag -001
=>
rerun xcorr-zacc10Hz-SCG -lag -1 ...
And it iterates determination of a residual slope and the a-priori
error value.
You may have use
of the SCG's short-term power spectrum exhibiting the
sensors
eigenresonance (excitation due to replacing the coldhead):
splist
-n/0300 -f0 -q -pdB -Hz ~/Ttide/SCG/o/G1_b_180628-1s.memsp MEM
The ascii-file ./gcf+sg/cal-zaccf0-lagl-YYMMDD-HH.tsf
contains 10,700 lines
>
0.66666667 0.219979E+01
0.173556E+01 0.672771E+00
0.68333333 0.257224E+01
0.256459E+01 0.251502E+00
0.70000000 -0.609250E+00 -0.586430E+00
-0.805768E-01
...
Minute
Seismo-ZACC
SCG
Diff
OPTIONS:
-GO
- Don't ask - no interaction except with fatal issues.
-NEW
- Process make-gcf-like-sg
Default is to use the existing files in likeg/
-PLOT
- After processing, do a separate run for the same date and time
to only plot.
The plots that are produced (inspect the
posted png's):
1. Cross-spectrum gain and phase
http://barre.oso.chalmers.se/hgs/4me/calzacc/cal-zacc10Hz-SCG-YYMMDD-HH.png
2. Power spectrum SCG and Seismo-Z acceleration (GGP-filtered)
http://barre.oso.chalmers.se/hgs/4me/calzacc/cal-zacc10Hz-SCG-YYMMDD-HH-psp.png
3. Time series
http://barre.oso.chalmers.se/hgs/4me/calzacc/cal-zacc10Hz-SCG-YYMMDD-HH-ts.png
-P
- Processing and a concluding plot stage
-lag #l
- Apply a shift l (lag < 0, lead > 0 ) to the 10 Sps
data.
The unit for l is 0.1 s
If the lag is new, the -NEW option must be given.
In order to find out the lag, run this script without
the -lag option and look at the files from segmented
processing
gcf+sg/ZACC10Hz-SG-??????-s??.xcorr
and in particular at the full-stroke result
gcf+sg/ZACC10Hz-SG-??????-??-all.xcorr
Use the lag (first column) with the highest cross-
correlation (you don't need to specify the leading `+´).
The report will contain an extracted list; however,
spurious large x-corr coefficients at large lags
may occur. A majority vote can be used.
-bf #f0
- Bessel filter scaling parameter f0;
internal default
in make-gcf-like-sg with resamp.tse,LIKEG is 0.0.174533
If this option is used, the resulting files will be
marked -f0
-err #err - A priori
error [1.0]
-R {<rep>|-} - Write a
short report to file rep ,
`-´ defaults to logs/cal-zacc10Hz-SCG-YYMMDD-HH-lagl.rep
If argument ends with a `/´, write report
to rep/cal-zacc10Hz-SCG-YYMMDD-HH-lagl.rep
-r
- Test existence of files and exit
EXAMPLE:
cal-zacc10Hz-SCG -NEW -lag 1 -GO -R - 210526 21
gets the gcf-data from Elder (if it exists) and analyses
without asking.
cal-zacc10Hz-SCG -GO -P -err 1000.0 -lag 1 -R - 210521 18 |\
tee tmp/cal-zacc10Hz-SCG.log
shows that the SCG runs into over-saturation in the
surface waves from the Earthquake at Southern Qinghai, China
2021-05-21 18 04 14 7.4 us-7000e54r 34.586 N 98.255 E
AFTERMATH:
Directly after a run for YYMMDD
HH ,
extract-xcorr gcf+sg/ZACC10Hz[f0]-SG-YYMMDD-s??.xcorr
(lag and start hour are not taken into the file names from
segmenting)
can be piped into xyz2grd to visually inspect the stability
of the lag of the central maximum of cross-correlation.
The cross-spectrum can be further processed:
For gain:
splist -q -f0 -Hz -A gcf+sg/sg-zacc-1s.csp CAD ADC
>! text-file-gain
For phase:
splist -q -f0 -Hz -Pd gcf+sg/sg-zacc-1s.csp CPH APH >! text-file-phase
You can try and find additional poles and zeros to that
flattens the
Guralp's response spectrum.
FILES PRODUCED:
Example
for -lag 0 210512 00 (no -bf):
./plot/cal-zacc10Hz-SCG-210512-00-xcorr.ps
./plot/cal-zacc10Hz-SCG-210512-00-ts.ps
./plot/cal-zacc10Hz-SCG-210512-00-psp.ps
./plot/cal-zacc10Hz-SCG-210512-00.ps
./logs/cal-zacc10Hz-SCG-210512-00-lag0.rep
./gcf+sg/cal-zacc-lag0-210512-00.env
./gcf+sg/ZACC10Hz-SG-210512-s10.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s09.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s08.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s07.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s06.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s05.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s04.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s03.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s02.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s01.xcorr
./gcf+sg/ZACC10Hz-SG-210512-s00.xcorr
./gcf+sg/ZACC10Hz-SG-210512-00-all.xcorr
./gcf+sg/G1_sb_210512-3h-10Hz.mc
beside fetched gcf-data in ./3u93z2/
After plotting:
./gcf+sg/sg-zacc-1s.csp
./gcf+sg/cal-zacc-lag0-210512-00.tsf
/home/hgs/www/4me/calzacc/cal-zacc10Hz-SCG-210512-00-xcorr.png
/home/hgs/www/4me/calzacc/cal-zacc10Hz-SCG-210512-00-ts.png
/home/hgs/www/4me/calzacc/cal-zacc10Hz-SCG-210512-00-psp.png
/home/hgs/www/4me/calzacc/cal-zacc10Hz-SCG-210512-00.png
.bye