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Re: FFT - Spectrum Analyzer
From: |
Francesco Potortì |
Subject: |
Re: FFT - Spectrum Analyzer |
Date: |
Tue, 12 Jun 2012 14:41:13 +0200 |
>For a long, non-stationary signal, you probably want to estimate the
>power spectral density of the generating stochastic process (lots of
>fancy words). This is done by the computing a "Welch periodogram".
>
>So long story short: type
>
>pwelch(input_signal,hamming(200));
>
>and play aroung with the length of Hamming window until you get the
>display you want. Octave's pwelch does not seem to plot on a dB scale,
>so you might want
>
>plot(20*log10(pwelch(input_signal,hamming(200)));
Since this is the power, 10*log10 should be the right way. Also, the
'db' argument to pwelch should produce a dB plot by itself. Have a look
at 'help pwelch' for all the options. Notice that pwelch is part of the
'signal' package, which should be installed in order to use it.
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- Re: FFT - Spectrum Analyzer, (continued)
- Re: FFT - Spectrum Analyzer, Thomas D. Dean, 2012/06/10
- Re: FFT - Spectrum Analyzer, Markus Bergholz, 2012/06/10
- RE: FFT - Spectrum Analyzer, Damian Harty, 2012/06/11
- Re: FFT - Spectrum Analyzer, Juan Pablo Carbajal, 2012/06/11
- Re: FFT - Spectrum Analyzer, Sergei Steshenko, 2012/06/11
- RE: FFT - Spectrum Analyzer, Damian Harty, 2012/06/11
- Re: FFT - Spectrum Analyzer, Francesco Potortì, 2012/06/11
- Re: FFT - Spectrum Analyzer, Robert T. Short, 2012/06/11
- Re: FFT - Spectrum Analyzer, Sergei Steshenko, 2012/06/11
Re: FFT - Spectrum Analyzer, Peter, 2012/06/11
- Re: FFT - Spectrum Analyzer,
Francesco Potortì <=