[time-nuts] Re: A hobby application of precise time or frequency

[Geoffrey Baehr]

Our group  (K6MTU) run one of the world wide HF DX propagation beacons, which are
all synced in assigned time slots around the planet. GPS derived. But we
are talking slots in seconds, not nS sync.  Credit goes to Kevin Rowett K6TD for building
this. https://www.ncdxf.org/beacon/ I know the ARRL runs a precise
freq test on an assigned schedule too, down to some fractional Hz, which is useful for things like
FT8/JT64 et al (look up Joe Taylor).

and this lash up, we sync/split time slots within each machine, but again, mS
for DMR. https://dmr.wa6ycz.org/ you can get an idea of our sensor networks too.
We sync seismometers against USGS for example. There is a *massive* sync’d
seismology net here in Calif https://www.cisn.org/ we are trying to join that.
The ham/hobby seismology guys are https://www.seismicnet.com/  all time syncd
tightly.

As hams, we also run a NASA Deep Sky Meteor camera system for meteor
tracking. https://meteorshowers.seti.org/ all NTP syncd.

FYI  interesting work going on with
LeoLabs phased array radars, sync’d globally as to
space junk tracking. Alaska vs New Zealand vs Eu  and soon mobile. Started
in SRI’s parking lot. Interesting how a ham / research project turned
in to a multi $100M company. All based on precise timing and ranging.
. https://leolabs.space/

Another interesting one is Wayne Rosing’s Las Cumbres Observatory which
runs a global Time Domain Astronomy system, many hams. It is
officially “amateur”, but NSF is now sponsoring some research on event
timing and synchronicity.
https://lco.global/

rgds to all.

g