Re: [Discuss-gnuradio] accumulate spectrum

[Marcus D. Leech]

On 05/30/2016 09:19 PM, madengr wrote:
> Try this:
>
> https://www.dropbox.com/s/7xsg4arx5h3gvah/spectrum.grc?dl=0
>
> The integrate with decimation is what you want.  Starting at 32 ksps with a
> 1024 length FFT length yields 31.25 vector/sec.  Then an integrate with
> decimation by 32 averages down to 0.98 vector/sec.
>
> However when I try reading those back from the file, I'm not getting the 1
> ksps I should be getting.  I have to set that throttle at 8000 to get the
> proper update rate.
>
> Lou
Files don't have any inherent sample-rate.  Regardless of what rate they 
were recorded at. Gnu Radio has no real "sense" of sample rate,
  and will process samples as fast as it can.  The only place where 
sample rate is "real" with respect to actual real-time is at the "edges"
  when the "edges" are controlled by actual hardware with an actual 
real-time-relative sample-rate.

If you read data from a file, Gnu Radio will vacuum it out just as fast 
as it can.


> Adellain TSIAHINA wrote
> > Dear All,
> >
> > I'm new to Gnu Radio. I looked carefully to the doc and tutorials but
> > could
> > not find any simple answer to my problem.
> > I have a radio signal from which I'm able to visualize the FFT in GNU
> > Radio
> > Companion.
> > Now I would like to save the FFT (more exactly the magnitude squared, or
> > the spectrum) accumulated over a given period of time (the average over
> > time) into a file.
> >
> > I found the following blocks in GRC that seem to be helpful:
> > - stream to vector
> > - FFT
> > - complex to mag
> > - file sink
> >
> > However I did not manage to save any accumulated spectrum...
> >
> > Any help (eg a woking example) would be very welcome!
> >
> > Thanks in advance.
> >
> > Adellain
> >
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>
>
>
> --
> View this message in context: 
> http://gnuradio.4.n7.nabble.com/accumulate-spectrum-tp60256p60265.html
> Sent from the GnuRadio mailing list archive at Nabble.com.
>
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