PSN-L Email List Message

Subject: Re: FFT Waterfall display
From: Larry Conklin lconklin@............
Date: Tue, 10 Jul 2007 17:49:44 -0400


Hi Angel,

Thanks for the info.  My original intention was to add a real time FFT 
waterfall display to my home brew data logging program.  I thought it 
would be interesting to watch the spectrum of an incoming event in 
addition to the time domain signal.  I'm not as interested in an after 
the fact, "postmortem" display.

I used some public domain C code for the FFT that wasn't very well 
documented.  I'm getting some sort of data in the waterfall, but it 
clearly ain't right.  Got side tracked and didn't get back to it. 
Somebody posted a link to a site that evidently has source code for the 
FFT and much better documentation.  When I get the time I'll take a look 
at it and perhaps replace what I had with something a little better written.

Larry


Angel wrote:
> Hello Larry,
> 
> Swarm does realtime spectrogrmas of log of frequency and log of power
> displays of seismic signals.
> 
> You could go directly to from winsdr to earthworm to a waveserver and
> from the wave server to Swarm.  I know what I just said is cryptic but
> if you need more detail I would be glad to get it to you.  I can send
> you a screen shot of what the display looks like if you want.
> 
> Angel
> \
> Sunday, July 8, 2007, 7:56:30 PM, you wrote:
> 
>> A couple of years ago I experimented with adding a real-time FFT 
>> waterfall display to my home brew data logging and display program. I
>> got the waterfall working just fine but there is something wrong with 
>> the FFT calculation that I never got around to debugging.  The current
>> discussion may motivate me to take another look at it.  If I manage to
>> get something working, it wouldn't be much additional effort to adapt 
>> the code into an independent program that would take PSN files as a data
>> source.
> 
>> Larry Conklin
>> Liverpool, NY
>> lconklin@............
>> __________________________________________________________
> 
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> 
> 
> 
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