AutoPyLoT Tuning

A description of the parameters used for determining automatic picks.

Filter parameters and cut times

Parameters applied to the traces before picking algorithm starts.

Name	Description
P Start, P Stop	Define time interval relative to trace start time for CF calculation on vertical trace. Value is relative to theoretical onset time if 'Use TauPy' option is enabled in main settings of 'Tune Autopicker' dialogue.
S Start, S Stop	Define time interval relative to trace start time for CF calculation on horizontal traces. Value is relative to theoretical onset time if 'Use TauPy' option is enabled in main settings of 'Tune Autopicker' dialogue.
Bandpass Z1	Filter settings for Butterworth bandpass applied to vertical trace for calculation of initial P pick.
Bandpass Z2	Filter settings for Butterworth bandpass applied to vertical trace for calculation of precise P pick.
Bandpass H1	Filter settings for Butterworth bandpass applied to horizontal traces for calculation of initial S pick.
Bandpass H2	Filter settings for Butterworth bandpass applied to horizontal traces for calculation of precise S pick.

Parameters used for determination of initial P pick.

Name	Description
tLTA	Size of gliding LTA window in seconds used for calculation of HOS-CF.
pickwin P	Size of time window in seconds in which the minimum of the AIC-CF in front of the maximum of the HOS-CF is determined.
AICtsmooth	Average of samples in this time window will be used for smoothing of the AIC-CF.
checkwinP	Time in front of the global maximum of the HOS-CF in which to search for a second local extrema.
minfactorP	Used with checkwinP. If a second local maximum is found, it has to be at least as big as the first maximum * minfactorP.
tsignal	Time window in seconds after the initial P pick used for determining signal amplitude.
tnoise	Time window in seconds in front of initial P pick used for determining noise amplitude.
tsafetey	Time in seconds between tsignal and tnoise.
tslope	Time window in seconds after initial P pick in which the slope of the onset is calculated.

Parameters used for determination of initial S pick

Name	Description
tdet1h	Length of time window in seconds in which AR params of the waveform are determined.
tpred1h	Length of time window in seconds in which the waveform is predicted using the AR model.
AICtsmoothS	Average of samples in this time window is used for smoothing the AIC-CF.
pickwinS	Time window in which the minimum in the AIC-CF in front of the maximum in the ARH-CF is determined.
checkwinS	Time in front of the global maximum of the ARH-CF in which to search for a second local extrema.
minfactorP	Used with checkwinS. If a second local maximum is found, it has to be at least as big as the first maximum * minfactorS.
tsignal	Time window in seconds after the initial P pick used for determining signal amplitude.
tnoise	Time window in seconds in front of initial P pick used for determining noise amplitude.
tsafetey	Time in seconds between tsignal and tnoise.
tslope	Time window in seconds after initial P pick in which the slope of the onset is calculated.

Parameters used for determination of precise P pick.

Name	Description
Precalcwin	Time window in seconds for recalculation of the HOS-CF. The new CF will be two times the size of Precalcwin, since it will be calculated from the initial pick to +/- Precalcwin.
tsmoothP	Average of samples in this time window will be used for smoothing the second HOS-CF.
ausP	Controls artificial uplift of samples during precise picking. A common local minimum of the smoothed and unsmoothed HOS-CF is found when the previous sample is larger or equal to the current sample times (1+ausP).

Parameters used for determination of precise S pick.

Name	Description
tdet2h	Time window for determination of AR coefficients.
tpred2h	Time window in which the waveform is predicted using the determined AR parameters.
Srecalcwin	Time window for recalculation of ARH-CF. New CF will be calculated from initial pick +/- Srecalcwin.
tsmoothS	Average of samples in this time window will be used for smoothing the second ARH-CF.
ausS	Controls artificial uplift of samples during precise picking. A common local minimum of the smoothed and unsmoothed ARH-CF is found when the previous sample is larger or equal to the current sample times (1+ausS).
pickwinS	Time window around initial pick in which to look for a precise pick.

Parameters used for checking quality and integrity of automatic picks.

Name	Description
minAICPslope	Initial P picks with a slope lower than this value will be discared.
minAICPSNR	Initial P picks with a SNR below this value will be discarded.
minAICSslope	Initial S picks with a slope lower than this value will be discarded.
minAICSSNR	Initial S picks with a SNR below this value will be discarded.
minsiglength, noisefacor. minpercent	Parameters for checking signal length. In the time window of size minsiglength after the initial P pick minpercent of samples have to be larger than the RMS value.
zfac	To recognize misattributed S picks, the RMS amplitude of vertical and horizontal traces are compared. The RMS amplitude of the vertical traces has to be at least zfac higher than the RMS amplitude on the horizontal traces for the pick to be accepted as a valid P pick.
jackfactor	A P pick is removed if the jackknife pseudo value of the variance of his subgroup is larger than the variance of all picks multiplied with the jackfactor.
mdttolerance	Maximum allowed deviation of P onset times from the median. Value in seconds.
wdttolerance	Maximum allowed deviation of S onset times from the line during the Wadati test. Value in seconds.

Parameters for discrete quality classes.

Name	Description
timeerrorsP	Width of the time windows in seconds between earliest and latest possible pick which represent the quality classes 0, 1, 2, 3 for P onsets.
timeerrorsS	Width of the time windows in seconds between earliest and latest possible pick which represent the quality classes 0, 1, 2, 3 for S onsets.
nfacP, nfacS	For determination of latest possible onset time. The time when the signal reaches an amplitude of nfac * mean value of the RMS amplitude in the time window tnoise corresponds to the latest possible onset time.