On 19.01.11 13:32, Doug Stewart wrote:
On Wed, Jan 19, 2011 at 3:19 AM, Rudolf
Widmer-Schnidrig <address@hidden>
wrote:
Dear List,
I have measured (in the time domain) input and output of a
mechanical system (a seismometer) and would like to derive a
filter model B(s)/A(S) based on this data.
I see the path via the frequency domain:
[H, F] = pwelch(input,output,.....'trans')
[B, A] = invfreqs(H,F,nA,nB)
Question: is there a way to find A and B without going first
into the Fourier domain?
many cheers - Ruedi
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Rudolf Widmer-Schnidrig
What Input did you use?
If it was an impulse then Yes
if it was a step then yes
and maybe more.
Doug
Dear Doug, I have used both a sweep and a random telegraph
signal. -Ruedi
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Rudolf Widmer-Schnidrig
Black Forest Observatory (BFO)
Heubach 206
D-77709 Wolfach, Germany
e-mail: address@hidden
phone: +49 7836 2151
fax: +49 7836 955240
48d 19' 48.24" North 8d 19' 23.13" East
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