Another AIS Class B glitch, & a parser in a pear tree
When Class B AIS finally gets going, there’ll be yet another issue to deal with: not all existing AIS plotting systems are going to fully understand the Class B messages. Apparently separate messages were anticipated in the original Class A standard but the slotting and details were changed in the final B standard that went official just this spring. I understand that the dynamic data—position, speed, etc.—will likely show, but the static stuff—boat name, etc.—may not until the plotter, ECDIS, radar, or whatever is updated.
A good place to see exactly how AIS messages are structured is Brian Lane’s AISparser.com. Among other resources is a neat demo that let’s you turn your own raw AIS strings into targets plotted in Google Earth. Brian is even running a sort of Christmas sale on his AISparser SDK, which I’d guess to be quite good. (Imagine the look on her face!)
And here’s some more good/bad B news: An AIS expert at the U.S. Coast Guard told me that two of the Class B transponders now awaiting USCG approval will “retail for under $900”. But he could not say whose, or when approvals may be issued. Neither could the FCC.
AIS Class B, messages & data fields
March 30, 2007
AIS SART plotting, & NMEA 2000 AIS problems
May 10, 2011
Simrad A150 Class B AIS, color yet
March 16, 2007
Class B AIS on sale, but not to Yanks!
April 10, 2008