# Homework Help: Averaging in tthe frequency domain

1. Sep 7, 2011

### Sklar Hast

Hi...
I have several Power Spectrua that I want to average into a single representative power spectrum. Then, I have to analize the amplitude spectrum of the average (i.e. sqrt(power spectrum))
Doing that doesn't give the same result as averaging the amplitude spectrums.

Supose I have tho spectrums that I want to average, each having one datapoint , whose power are A and B, respectively. a and b are the square roots of A and B, so

a^2=A
b^2=B

Method 1:
sqrt{ (A+B)/2 }= sqrt{ (a^2+b^2)/2 }

Method 2:
(a+b)/2

I suspect that I'm coliding with Schwarz innequality (or triangular inequality)

What do you recommend me to progress in my ferequency domain analisis???

Thanks