AIS transceiver

[Maren]

In a number of recent threads the benefits of AIS, in addition to radar, have been discussed. The problem is that in the US, the FCC has been slow to grant approval to the Class-B standard.

Boaters in the US have been left with the option of purchasing a Class A system which has most but not all of the features of a Class B. The problem is if you are an early adopter, you could get left in the cold when/if they finally do approve the system is approved. That seems likely since the Coast Guard has asked for it, but that was well over a year ago.

Shine Micro has a workaround that you might find interesting. It’s a Class B system but is software locked to Class A until the standard is approved in the US and you activate it.

[MarkJ]

Can't you just find a method to ship it outside the USA?

[sandy daugherty]

AIS class B is a subset of Class A, which is required on Ships over 300 Tons. Class A costs something like $3500, and Class B is around $1000 to $1500. What is available today in the US is either Class A or a receive-only radio, at $190 to $1500 depending on manufacturer and specs. The most popular radio is the SR-161, which switches back and forth between to two frequencies used by AIS, or the @$400 SR-162 which monitors both frequencies simultaniously(SP?)

[speciald@ocens.]

The ACR unit was available in St Maarten last Winter and quickly sold out. I did recieve an AIS signal off a 39 foot sailboat on my way to Bemuda this spring - I called on Vhf and he confirmed it to be the ACR unit. The problem as I see it is activating these units in-shore. The number of signals could become overwhelming and would cause large ships to shut off class B reception thus negating the saftey value of the class B transmitters. I will probably install an ACR unit this Fall but limit its use to off-shore.

[sandy daugherty]

"The number of signals could become overwhelming and would cause large ships to shut off class B reception thus negating the safety value of the class B transmitters."

The FCC may be pondering some Solomonic solution to that question, but in truth it will happen exactly once. The ensuing litigation will keep every Class B AIS brightly lit on every Class A AIS screen within the US Territorial limits.

I will have an ACR the minute they become legal, and I plan to keep it mute unless conditions call for it, as on the open ocean in shipping lanes, or if some idiot self-inflicted emergency leaves me adrift with no way on.

But will the FCC agree with the Coast Guard that such decisions can be left to the whims of a recreational sailor?

[defjef]

The engineers will have to develope a silent or in the background mode which "wakes" up if there is a collision situation in the making. There is sufficient computing power to do this for vessels underway. Those moored or at dockside need to be on silent mode or turned off. If every boat over 30' had a transceiver you would be overwhelmed by the data on your screen and it would be useless.

[dacust]

Originally Posted by defjef

The engineers will have to develope a silent or in the background mode which "wakes" up if there is a collision situation in the making. There is sufficient computing power to do this for vessels underway. Those moored or at dockside need to be on silent mode or turned off. If every boat over 30' had a transceiver you would be overwhelmed by the data on your screen and it would be useless.

If I am in a harbor with hundreds pf markers showing on my screen, they don't confuse me unduly. I look at the ones closest to me. If the radar shows hundreds of returns, I'd look at the ones important to me for what purpose I am using it.

My software has a mode where I can have it show only markers that are visible from my location. Or it can show only the lighted markers.

IF, I am seeing all that information, it is also telling me something. It tells me I am in a crowed location and I should be paying attention. For radar, maybe it's warning me that there is some kind of function going on the has loads of boats milling around in a particular area.

For AIS targets it should be the same thing. If I see hundreds of targets, that tells me something valuable. I look at the ones close to me. Then the software should have filters. Only show a dot for ones that don't concern me. Only evaluate the ones for collision if they are within a certain range/speed.

I think the transmitter should ALWAYS be on while underway. Only time it should be off would be in a slip. The software and operator should be responsible for weeding out the ones that don't matter and reducing the data down to a useful volume.

[sandy daugherty]

DefJef: This is not new technology, its been in everyday use all around the world for 7 years. We can't have AIS B in the US because the FCC hasn't certified the radios. Part of the problem is that the FCC auctioned off the frequencies, won't admit they screwed that pooch, and got their noses bent out of shape in the resulting minifuror. No more engineering is required, no more rules need to be contemplated, and no one outside the FCC has any reservations about just approving it. Many manufacturers have warehoused radios, waiting for FCC approval, causing some of them financial problems. If you would like to read more about the issue, go to Panbo.com and go thru the AIS thread. It is a disgusting case of Federal Government indifference to good ideas from somewhere else. It leaves lives at stake in US waters, while they drool over the next auction, and joust with the cable companies, where no one is going to get any more than a bruised index from all the finger-pointing.

I guess I'm pretty wishy-washy about this.