[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] Passive radar using my hacked dual coherent chann
From: |
Marcus D. Leech |
Subject: |
Re: [Discuss-gnuradio] Passive radar using my hacked dual coherent channel rtl_sdr dongle |
Date: |
Fri, 27 Sep 2013 14:16:05 -0400 |
User-agent: |
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.24) Gecko/20111108 Fedora/3.1.16-1.fc14 Thunderbird/3.1.16 |
On 09/26/2013 11:27 PM, Jared Clements wrote:
Since they're clocked together I would assume that your alignment
would consist of interpolation on the primary FM signal, what do you
do to remove it later? If your code is too messy to release can you
share a block diagram?
Thanks,
Jared
I just re-did my tests with a pair of synched dongles, and instead of
inject RF externally, I just tuned it close to the 2nd harmonic of the
clock.
That produced quite stable, near-perfect, correlation, once I adjusted
the phase to peak up the correlator output. This puzzles me greatly.
This implies that both dongles are properly phase-locked to the master
clock, and that the leakage is being coherently downconverted, and
that no samples are being dropped.
So, my phase-coherence issues are with my external RF injection. Which
I just plain don't understand....
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org