Paul,

I have received AIS data in the Seattle VTS zone repeated from bouys. I
think the SF area has it as well. Enough AIS for me tonight. I have to
get cracking on my handheld sail racing software

Cheers,
-Mark


Paul wrote:
wrote in message
oups.com...
Paul, this is very impressive. Is there a chance noaa is repeating
traffic from a bouy in your area?

-Mark


Paul wrote:
I just received a SR162 dual-channel AIS receiver, which I will be using
on
my sailboat -- the old single-channel SR161 will end up at home. I've
been
testing at my house it these last couple of days, and have been amazed at
the range I have been getting. I've seen many ships 100 to 200 nautical
miles from my position, and last night saw one at 492 miles, and another
at
673 miles" (this one was "Ikarugu", a freighter heading to Long Beach,
CA)

Of course, I also moved my whip antenna from the deck railing to the
roof,
which has to help a tiny bit. I am at about 1000ft elevation, 4 miles
from
the coast, and 40 miles north of the Golden Gate Bridge. Still, this is
so
far beyond line-of-sight that it has to be tropospheric ducting.
Occasionally, VHF signals make the trip from Hawaii to California (about
2000 miles), and an interesting by-product of widescale AIS deployment is
that there are now all these AIS "beacons" spread out all over the
oceans,
running continuously.

AIS DXing - who holds the record?

-Paul

Mark,

The "AIS repeater" thought did occur to me, and I haven't researched it, but
I am not aware of any AIS repeaters in the area. The DX signals do seem to
be most prevalent when the local "marine layer" (fog) comes in in the
evening, and I am assuming that the ducting, if that is what's really going
on, is occuring when there is stratification in the lower atmosphere. Also,
my best DX was from the "Ikaragu", at lat 30.57N lon 132.56W, which is about
630 NM out from the nearest coastline. I would be very surprised if there
were repeaters within LOS of that point, and if so how would they send the
signal back to the mainland? They could use satellite, but that seems
unlikely. Further speculation on my part would be silly...

Does anyone know if there are any AIS repeaters currently operational? This
technology is so cool, but I have to remind myself occasionally that it
isn't infallible -- see my recent posting about AIS position errors.

-Paul