# Fwd: Log raw data from the usrp\_spectrum\_sense.py

**URL:** <https://www.ruby-forum.com/t/fwd-log-raw-data-from-the-usrp-spectrum-sense-py/233331>\
**Category:** GNU Radio\
**Created:** [December 4, 2014, 7:51pm UTC](https://www.ruby-forum.com/t/fwd-log-raw-data-from-the-usrp-spectrum-sense-py/233331 "2014-12-04T19:51:48Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [December 4, 2014, 7:51pm UTC](https://www.ruby-forum.com/t/fwd-log-raw-data-from-the-usrp-spectrum-sense-py/233331/1 "2014-12-04T19:51:48Z")

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Marcus

This is an explicit answer and guide to the exact tutorials _I_ needed  
to  
start capturing my particular dataset.

That said, a question on refinement (and I can put this on the list if  
you  
think there’s sufficient interest):  
Rather than capturing all the spectrum “all the time” I would like to  
create a GRC flowgraph (at least until I’m comfortable writing my own  
code)  
that will bin samples, look for a particular amplitude spike, and save  
the  
bin if the spike is detected. The specific application is to look at  
characteristic spectra of cloud-ground and cloud-cloud lighting  
impulses.

Do you have a suggestion?

Regards  
Gerry  
"  
Hi Gerry,

I think it would be cool if you forwarded this to the list 🙂 Generally,  
it’s never bad to ask one question too many, and if something  
interesting comes out of a discussion, everyone will profit.

I think with “binning samples” you might need to channelize them into  
different subbands?  
You could do that with a set of band pass filters. This will surely be  
functional, but will have a high computational load.  
If your subbands are equally shaped, you could use the Polyphase  
Channelizer to get a set of subbands, which will be much more efficient.

On each of these N subbands, you could use a squelch and only save the  
passing signal into N file sinks.

Greetings,  
Marcus  
"

Thanks, Marcus. I’ll be looking at Polyphase Channelizer as soon as I  
can  
get back to that system!

Regards  
Gerry

On Mon, Dec 1, 2014 at 10:29 AM, Marcus Müller  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> that does that, or use python, octave, matlab, C, C++, or whatever you  
> guided tutorials 1, 2 and 3, and most of your questions will be answered 🙂
> 
> > collect the a wide band signal around and save the data to the txt file,

[http://gnuradio.4.n7.nabble.com/Log-raw-data-from-the-usrp-spectrum-sense-py-tp51503p51506.html](http://gnuradio.4.n7.nabble.com/Log-raw-data-from-the-usrp-spectrum-sense-py-tp51503p51506.html)

> removed\_email\_address@domain.invalid  
> [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)

–  
Gerry Creager  
NSSL/CIMMS  
405.325.6371  
++++++++++++++++++++++  
“Big whorls have little whorls,  
That feed on their velocity;  
And little whorls have lesser whorls,  
And so on to viscosity.”  
Lewis Fry Richardson (1881-1953)

–  
Gerry Creager  
NSSL/CIMMS  
405.325.6371  
++++++++++++++++++++++  
“Big whorls have little whorls,  
That feed on their velocity;  
And little whorls have lesser whorls,  
And so on to viscosity.”  
Lewis Fry Richardson (1881-1953)