[MSNoise] One more clarification

[Lukas Preiswerk]

Hi Ashton,

I can partly answer 1) and 3). First, corr_duration would be 30*60 in
their paper (corr_duration is in seconds). As far as I understand,
analysis_duration should almost always be 86400. Setting the
analysis_duration
smaller could be used to prevent loading a full day of data for
specific cases, like super high frequency data (8kHz or more). The
remaining processing still works on days and not multiples of
analysis_duration. For examplem if you set analysis_duration to 3600,
then you only use 1 hour of data each day…

Hope that helps!

Lukas


2016-10-11 18:57 GMT+02:00 Flinders, Ashton <aflinders at usgs.gov>:
> Hi all, I was just reading through Taka'aki and Forents new paper using
> MSNoise, and was hoping just for a wee bit more clarification on the
> MSnoise processing scheme (wasnt quite clear in the docs).
>
>
> The paper says;
> "We first removed the instrument response from 1-day-long waveform to
> obtain ground motion in displacement. Daily displacement data were
> bandpassed between 0.08 and 2.0 Hz, down-sampled into 10  Hz, and split
> into 30-min-long data. Those 30-min-long data were spectral whitened in a
> frequency range of 0.1–0.9  Hz and then one-bit normalized. With those
> one-bit normalized data, the NCFs were computed for all possible
> combinations of components. Daily NCFs were then obtained by stacking
> 30-min NCFs."
>
>
> Q1) So just in terms of implementation in msnoise admin, the 30-min-long
> duration would be controlled by "analysis_duration" correct?
>
> Q2) If you remove the instrument response, is it always removed from a 1
> day chunk, or is it removed from a chunk equal in size to
> "analysis_duration"? (the docs say 1 day, but I wasnt sure if this was just
> referencing the default "analysis_duration" time).
>
> Q3) This probably isnt the intended usage, but if you used
> "analysis_duration" longer than a day, would you expect things to behave?
>
> Thanks as always!
>
> -ashton
>
>
> p.s. paper;
> http://earth-planets-space.springeropen.com/articles/10.1186/s40623-016-0538-6
>
> --
> Ashton F. Flinders, Ph.D
> U.S. Geological Survey
> 345 Middlefield Road
> Menlo Park, CA 94025
> (650) 329-5050
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