[Discuss-gnuradio] determining rms of AM carrier

[ematlis]

Hello-

I am interested in determining the rms strength of the carrier of an AM 
modulated waveform, and displaying it in realtime, perhaps as a windowed 
average value.  I am using the LFRX boards on the USRP.  This question probably 
comes up a lot in the SNR and RSSI related posts, but perhaps not specifically 
for my application.  Are there currently tools available in the gnuradio libs 
for this?  If not, I would appreciate a run-down of what technique is needed to 
do this, and if there are any related codes that can be used as a guide.  In 
principle it would seem to me that just measuring the rms of the I or Q stream 
would be sufficient if the modulation index is low (which it is).  If not, then 
perhaps dividing the I or Q stream with the modulation (obtained with 
gr.complex_to_mag())?

Thanks,
eric