I've been playing with my SR-162 AIS receiver, and the ShipModul Miniplex
42BT, and have been watching this strange vessel that has been parked about
50 to 100 NM offshore of San Francisco for the last several days. The name
is SBX-1, and I couldn't locate the name, the call, or the MMSI in any of
the regular databases. There has been a tug named "Dove" running in and out
of S.F. Bay then holding station a few hundred feet from SBX-1. I had been
suspecting that I was watching a drug transfer or something (but with the
AIS transponders turned on???), until I finally did some google searching.

It turns out that SBX-1 is Sea-Based X-Band Radar -- a floating,
self-propelled, mobile radar station designed to operate in high winds and
heavy seas. It is part of the United States Government's Ballistic Missile
Defense System. (from the Wikipedia entry:
http://en.wikipedia.org/wiki/Sea-based_X-band_Radar ). The Dove is the
SBX-1 support vessel. The SBX-1 semi-submersible hull was built in Russia's
Vyborg shipyard. The superstructure and radars were installed in Texas, and
SBX-1 was then sent through the Straits of Magellan to Pearl Harbor. It is
to be based in Adak Island in the Aleutian Islands, but it is obviously
mobile, and for some reason is now near San Francisco.

Here is another link about SBX-1:
http://eyeball-series.org/sbx1-birdseye.htm

My location is about 40 miles north of San Francisco, and is a few miles
from the coast at an elevation of 1000 ft. I regularly see AIS signals out
to 100 miles, and if the tropo ducting is active, I can receive from much
further out. My record so far is about 1000 NM, around the tip of Baja
California (Mexico).

There is some pretty strange stuff out there!

-Paul