m.data is what they use to calculate power_db (i.e. power_db = 10* math.log10(m.data[i_bin]/tb.usrp_rate) - noise_floor_db) from this code https://github.com/gnuradio/gnuradio/blob/master/gr-uhd/examples/python/usrp_spectrum_sense.py
line 303. How would I calibrate my system with an external signal? I don't understand what you mean by this. On Wed, Jun 10, 2015 at 5:01 PM, Marcus Müller <[email protected]> wrote: > Hi Ashraf, > > that's no real power -- it's the absolute magnitude of the FFT in each > bin, in dB relative to 1. > If you need numbers in real power (ie. numbers on your screen that > directly relate to a signal power in real physics), you will need to > calibrate your system with an external signal of which you know the > (physical) power of. This will only apply for a short time, for a given > configuration of frequency, sampling rate, gain. > I don't know what you mean with m.data, but I think you're on to nothing > correct. > > Best regards, > Marcus > > On 06/10/2015 09:50 PM, Ashraf Younis wrote: > > I have been running usrp_spectrum_sense.py for hours now and I cannot > figure out where it is getting its power_db from. I narrowed it down to > m.data. My end goal is to have the program scan frequencies from a desired > list that I have created and output its power. usrp_spectrum_sense.py scans > frequencies in a range and I have been successful in reading a file of > known frequencies in usrp_spectrum_sense.py. I what to be able to pass a > list of frenquencies (floats) into the program and let it scan for the > power. But the program computes power from m.data and now from its own > variable 'freq'. Can someone explain to me what these numbers (m.data) are? > > > _______________________________________________ > Discuss-gnuradio mailing > [email protected]https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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