Hi
Thanks to everyone for your great efforts!
This email provides some documentation on our distribution
of GnuRadio tuned for Radio Astronomy, using Raspberry Pi 4s.
We’ve recently had a breakthrough in solving some problems with
accurately capturing short term transient events in radio signals, that
is likely useful in other research areas. The NsfDetect.. designs
are on GitHub (ie git clone http://www.github.com/WVURAIL/gr-radio_astro).
We have put together a test system using a GPS 1 PPS signal and are
now getting 100% capture rate for 10 minute long tests. We hope
to get to 1 microsecond time accuracy (based on GPS time tags).
There are some subtlety to getting to this time accuracy, as the PI seems
to have scheduling jitter at the 1 millisecond level, but by
counting samples and regularly logging the count versus time we
may be able to recover the time to 1 microsecond. The figure show
20 seconds of samples aligned by detection of the event.
The plot labels are HH MM SS _ milliseconds
The documentation is a google doc shared.
https://docs.google.com/document/d/10SegmKq_nLdu9Da8dwwof2xG5J1gole3f95JdRaEIxQ/edit?usp=sharing
The folks at SDRplay packaged Gnuradio into a very convenient Raspberry
PI OS release. We’ve further updated this and are releasing the
very specific versions as a 2.7 GB compress Pi OS.
https://drive.google.com/file/d/12QfEosneqLEIQL4mx86z0q3VjvDUbd2x/view?usp=sharing