Jeff Thanks for the pointers. I'll try these some time this week... hopefully before we see more lightning (Wed/Thurs). I do appreciate the help.
Regards Gerry On Mon, Sep 29, 2014 at 3:53 PM, Jeff Long <willco...@gmail.com> wrote: > Gerry, > > It will probably take a bunch of experimentation to find something that > works. Since you're probably interested in the very beginning of the > signal, you'll need to do power detection in parallel with a delayed > version of the signal so you trigger in time. Look up some of the following > blocks: > > - Delay > - RMS > - Burst Tagger > - Tagged File Sink > > Since you're capturing fairly short events, try recording bursts at full > capture bandwidth (e.g., 1 MHz) to files, then do post processing as a > second step. Find or make up some test signals to feed your flowgraph so > you can work on it in good weather. > > - Jeff > > > On 09/29/2014 04:20 PM, Gerry Creager - NOAA Affiliate wrote: > >> I'm trying to become familiar with gnuradio, starting with grc, but I've >> run into a couple of stumbling blocks. >> >> I'm using a USRP1 with an assortment of daughter boards, including LF-HF >> and VHF capabilities. I'd like to be able to sample the spectrum in >> relatively small segments, and capture the sample to a file, for >> particular amplitude exceedances. To be specific, I'm looking at >> lightning impulses and attempting to capture narrow segments of its >> discharge spectrum for analysis. Most of this will be below 100 khz, >> although I'm interested in systematically sampling from 10khz to 1 MHz. >> Of I can capture sufficient samples, I'll perform wavelet and FFT >> analyses against them, to see if I can identify patterns. >> >> Could someone spare a clue to a new guy, and point me either toward an >> appropriate starting point in Python, or a good place to start in a grc >> flowgraph? >> >> Regards, >> Gerry >> -- >> Gerry Creager >> N5JXS >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > 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)
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