Frequency Synthetesis Spectrum with filtered signals (Convolution)

[kkloo]

Hello,

I'm a new user of DIAdem and i do signal analysis.

To treat my acquisitions, I use several tools alreaydy implement in DIAdem. But I want do some convolution of several signal to make a synthesis spectrum.

Actually, I want to filter several frequency on a signal and put them in a same spectrum, I think about a convolution of each signals.

How can I do that with DIAdem?

Best regards

Pascal GRAIGNIC

[Brad_Turpin · Accepted solution]

Hi Pascal,

I'm no expert in acoustical analysis, but it seems to me that you could simply add together the resulting channels from each of the single frequency digital filter ANALYSIS function results.  The result of the digital filter calculation in DIAdem is a time series curve that contains only the desired frequency component(s) with a magnitude proportional to the relative amplitude contribution of said frequency component(s) to the original (full) time series curve.  There is a multichannel summation function in the "Basic Mathematics" ANALYSIS palette.

Brad Turpin
DIAdem Product Support Engineer
National Instruments

[kkloo]

Hi Brad,

First of all,  thank you for your help and the solution you gave.

It's so simple that it makes it a great solution 😉 I use your method and it works !

In fact, it's the definition of Fourier Transform ! A signal is a sum of sinusoide! (It seems that I must return to school...)

So I used filter analysis in different frequency which are the fundamental and its harmonic and recompose the signal. I can continue my project now. 

Thanks again.

Merry Christmas Brad

Pascal