How to calculate Standard Deviation from Spectral Ratios

[rizhu]

Hello all Geopsy users.

I'm trying to calculate the standard deviation (with seismic analysis code, sac from iris) from spectral ratios and compare with those calculated by Geopsy.

Do you know the formula that Geopsy uses?

or

Do you know some article that explain this?

Thanks a lot.

[sbirro]

Hello,

it should be the geometric sample standard deviation.

You can read the formula in the Deliverable D08.02, pag. 8. It is one of the deliverables of the SESAME project. Since the SESAME project website seems discontinued, look for it using the Internet Wayback Machine (http://archive.org/web/web.php).

Riccardo