More AIS…bad data, bad plot?
What’s wrong with this AIS target, seen off Naples, Florida, a couple of weeks ago (with the Si-Tex receiver)? How about a bogus MMSI # (only 4 digits), no name, and destination as “HOME”...
Category: AIS
Class B AIS, part 2
Today, I’m afraid, we must speak of “frequency agility.” Part of the Class A standard is that transponders must be able to change channels if ordered to by the presiding local coastal authority. The digital command is received...
Class B AIS, the devil’s in the details, part 1
Finally I have some specifics about the Class B AIS transponder standard, which is “very close” to finalization: • Like Class A, static data will be broadcast every 6 minutes on alternating channels. A...
Now it’s the Si-Tex/Nasa/Nobeltec AIS receiver
It turns out that Nobeltec has decided to market the Si-Tex (Nasa) single frequency black box “AIS100” receiver instead of the Comar SLR-100 as I had first presumed. I dare say that this move, along with adding AIS...
AIS target received, goal achieved
I felt like a spy in an old WWII movie, rigging a VHF antenna and GPS on the patio outside my hotel room late at night, then hunching over my laptop hoping for certain transmissions…but,...
Nasa/Si-Tex AIS receiver, first impressions
Well, I’m beginning to understand why the Nasa AIS receiver is so much less expensive than most others on the market (besides the single frequency business). For one thing, the wire connections to the “not waterproof”...
Adveto advanced AIS presentation, & more
The animation above shows how AIS system data can be used to predict a vessel’s future track, even “bottom sweep”—in this case 2 minutes ahead of its actual position, speed, rate of turn, etc. It’s...
Safe Pass plotting, why not?
Fred Pot showed me a really interesting new concept in target plotting that was developed at a Dutch maritime school. Currently many plotters/PCs and radars can automatically use ARPA and/or AIS info to calculate the CPA (Closest Point of...
Fred Pot, AIS man
It was an honor to be visited by Fred Pot last week. Fred is a Dutch marine engineer and consultant who’s been involved in AIS from the beginning. He currently lives on the West Coast, represents...
More AIS listener, hard & soft
There’s an interesting thread about the Chinese-built SmartRadio AIS receiver (click ENG upper left when you get there) over at rec.boats.electronics, but I would caution readers that the $200 price cited seems to be introductory wholesale. (The dual...
