Garmin and ATONs with AIS.

Complete AIS support is apparently not a priority for Garmin - reportedly they also used to crash on receiving an AIS SART or MOB message (now fixed in a firmware update). I guess they do some basic testing with class A and B vessel messages and ignore most of the rest of the spec (which is, to be fair, voluminous).

Pete
 
It's not only Garmin that are having problems with AIS.

I have a Furuno NN3D plotter, it will not show MOB sart - I have been discussing this issue with Furuno for more than a year.
In the spring they finally acknowledged it to be a problem, the reason the MOB sart was filtered out was that it didn't transmit values for COG/SOG of the MOB...
It will however show ATON's but it uses the same icon as a boat/ship.
I'm still waiting for a software update...

There are four different AIS target types in addition two class A and B vessels. They have got different series of MMSI numbers.

1) Search and Rescue Transponders (970yyzzzz) aka normal SART
2) Man overboard DSC and/or AIS devices (972yyzzzz) aka personal SART
3) 406 MHz EPIRBs fitted with an AIS transmitter (974yyzzzz)
4) navigational aids (AtoNs; 99MIDaxxx)

My Raymarine i70 and Open CPN seems to display AIS data correctly :)
 
knuterikt said:
There are four different AIS target types in addition two class A and B vessels. They have got different series of MMSI numbers.

1) Search and Rescue Transponders (970yyzzzz) aka normal SART
2) Man overboard DSC and/or AIS devices (972yyzzzz) aka personal SART
3) 406 MHz EPIRBs fitted with an AIS transmitter (974yyzzzz)
4) navigational aids (AtoNs; 99MIDaxxx)
Click to expand...


Don't forget SAR aircraft, and "base stations", which can also transmit their positions. Plus all the various other types of non-location message in the spec, like "DGNSS broadcast binary message", "Multiple slot binary message with Communications State", "Safety related broadcast message" and so on and so on. It's a very complicated system, and plotter manufacturers (for whom AIS is merely another feature on the list) have tended to just do the most obvious and widely-used bits. Then get caught out when real world usage expands past that.

Pete
 
david_bagshaw said:
In the ribnet posting is asked which combinations work

digital yacht class b and open CPN do.
Click to expand...

Vesper Watchmate displays handle AtoNs, AIS SARTs, and AIS MOBs, with the proper IMO symbols and all the special fields (for example, the altitude of a SAR aircraft, or whether an AtoN is the position of an actual buoy or merely a virtual marker). The SART and MOB messages are handled specially, sounding an alarm even if the device is otherwise muted, and jumping out of any menus etc to a clear "how to get back to them" display.

I would also expect it to handle any other esoteric messages that come along, because the people who make it are dedicated to AIS and have a deep understanding of it (they also make base stations used to broadcast those AtoNs) - rather than general developers for whom AIS is just another annoying feature.

Pete
 
prv said:
Don't forget SAR aircraft, and "base stations", which can also transmit their positions. Plus all the various other types of non-location message in the spec, like "DGNSS broadcast binary message", "Multiple slot binary message with Communications State", "Safety related broadcast message" and so on and so on. It's a very complicated system, and plotter manufacturers (for whom AIS is merely another feature on the list) have tended to just do the most obvious and widely-used bits. Then get caught out when real world usage expands past that.

Pete
Click to expand...
Should not be complicated to write a program that can send all types of AIS messages via NMEA to test compatibility with different AIS targets and messages :)
 
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