PSN-L Email List Message

Subject: Re: Re[2]: FFT Waterfall display
From: "Michael Kimzey" mckimzey@...........
Date: Sat, 14 Jul 2007 08:09:29 -0400

Hi all.

>The power needed for a realtime FFT display
>of any value just does not exist for a typical
>home computer. You would need a special
>card like these high speed video cards.
>I have seen the machines that do real time fft
>and back in the 1970s they were like 1000X faster
>than your home computer and would do 500 points
>and be only a few milli seconds behind real time.
I'm don't completely understand all this FFT stuff, but a search of google 
revealed that you can get several programs for FFT and waterfall display.
Spectrogram 5.1  <- provides a discussion 
of FFT and source code.
Digipan - this is a amature radio program for communicating digitally using 
audio output from your sound card and has a very nice waterfall display.
Spectran 2.0

Maybe these are not doing something "FFT-wise", but Spectrograph and 
Spectran both allow you to set the FFT size and both have the moving 
graphical display...and are working on signals with sample rates of 44,000 
per second.  I think that any seismological waterfall display would move 
-very- samples-per-second are only 10 and should be able to 
perform some type of FFT.  Even Win-Quake does FFT.  Maybe I'm missing 

- Mike


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