geopsy.org

Hello all.

I'm trying to calculate the standard deviation (with seismic analysis code, sac) 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.

The curves computed for each time window are averaged on a log scale (geometrical mean). Geometrical standard deviations are thus computed.