The analysers.noise_analyser
module¶
- class grond.analysers.noise_analyser.analyser.NoiseAnalyser(nwindows, pre_event_noise_duration, check_events, phase_def, statistic, mode, cutoff, cutoff_exception_on_high_snr)[source]¶
From the pre-event station noise variance-based trace weights are formed.
By default, the trace weights are the inverse of the noise variance. The correlation of the noise is neglected. Optionally, using a the gCMT global earthquake catalogue, the station data are checked for theoretical phase arrivals of M>5 earthquakes. In case of a very probable contamination the trace weights are set to zero. In case global earthquake phase arrivals are within a 30 min time window before the start of the set pre-event noise window, only a warning is thrown.
It is further possible to disregard data with a noise level exceeding the median by a given
cutoff
factor. These weights are set to 0. This can be done exclusively (mode='weeding'
) such that noise weights are either 1 or 0, or in combination with weighting below the median-times-cutoff noise level (mode='weighting'
).
- class grond.analysers.noise_analyser.analyser.NoiseAnalyserConfig(**kwargs)[source]¶
Configuration parameters for the pre-event noise analysis.
- ♦ nwindows¶
int
, default:1
number of windows for trace splitting
- ♦ pre_event_noise_duration¶
float
, default:0.0
Total length of noise trace in the analysis
- ♦ phase_def¶
str
, default:'P'
Onset of phase_def used for upper limit of window
- ♦ check_events¶
bool
, default:False
check the GlobalCMT for M>5 earthquakes that produce phase arrivals contaminating and affecting the noise analysis
- ♦ statistic¶
str
(pyrocko.guts.StringChoice
), default:'var'
Set weight to inverse of noise variance (var) or standard deviation (std).
- ♦ mode¶
str
(pyrocko.guts.StringChoice
), default:'weighting'
Generate weights based on inverse of noise measure (weighting), or discrete on/off style in combination with cutoff value (weeding).
- ♦ cutoff¶
float
, optionalSet weight to zero, when noise level exceeds median by the given cutoff factor.
- ♦ cutoff_exception_on_high_snr¶
float
, optionalExclude from cutoff when max amplitude exceeds standard deviation times this factor.