Alternative magnitude implementation: amplitude ratio between template and detected event

[damb]

Discussed in https://github.com/damb/scdetect/discussions/55

^{Originally posted by **mmesim** November 4, 2021} Ideas for magnitude calculation based on what is already available and used in the literature (etc). - **Amplitude ratio between template and detected event** e.g https://www.nature.com/articles/ngeo697 [...]

Details:

• use the approach as an alternative to compute a station magnitude
• consider only those streams which are used for detection
• the time window length is equal to the length of the template waveform
• Processing:
  • the linear trend is removed
  • the mean is removed
  • a filter is applied
  • finally the waveform is trimmed.

• The process is to find the maximum amplitude for each template and the corresponding detection for each station and channel. Then compute the ratio for all these pairs, and take the median.

[damb]

Both the amplitude and magnitude are going to be named MRelative.

[damb]

@mmesim, for clarification: if a detector configuration includes a vertical instrument component, MRelative is going to be computed under consideration of that vertical component, too. Though, in any case the reference station magnitudes are MLhc/MLh. Do you agree with this?

[mmesim]

Yes.