Class B AIS waste of money

[Paul Elliott]

Originally Posted by CarinaPDX

Good grief. I will stand with my conclusion that AIS is not fundamentally a transponder technology. The ability to respond to requests, on an exception basis, doesn't alter that.

I suspect the choice of the word "transponder" was intentionally misleading by the proponents of AIS. Partly it was using the known concept of a radar transponder to explain it, and partly it was a way to draw attention from the truth: all ships would be constantly sending out their positions (not to mention cargo and destination) in plain text for all to see. So it was a means of getting acceptance without raising uncomfortable facts - just like our politicians.

I'll use the technically more accurate description: transceiver.

Greg

I suspect that you're right about the origin of the term coming from the familiar radar transponder. And I will agree that the AIS transponder is just barely a true transponder. And I don't mind one bit if you want to call it a transceiver -- you're certainly right about it being a transceiver, and the terms aren't mutually exclusive.

But I do not like seeing someone who uses the transponder nomenclature being called ignorant for doing so. That's just not right -- for a number of very good reasons.

[El Pinguino]

Originally Posted by Paul Elliott

I suspect that you're right about the origin of the term coming from the familiar radar transponder. And I will agree that the AIS transponder is just barely a true transponder. And I don't mind one bit if you want to call it a transceiver -- you're certainly right about it being a transceiver, and the terms aren't mutually exclusive.

But I do not like seeing someone who uses the transponder nomenclature being called ignorant for doing so. That's just not right -- for a number of very good reasons.

I don't know if that many people are familiar with radar transponders.

I'm the only person I have ever met who had one on board ( a SART.... fell off the back of a ship... expired battery ) and most would not be aware that Racons are transponders.... and transponder is not used in the name of either one.

[Dockhead]

Originally Posted by SV Enough

.. .
And no, bridge crew haven't a clue about electronics much past the power button and the quick reference guide.

Blind leading the blind. This is truly scary stuff.

IF it's true, which I doubt. The training is better than that in the U.S. military, AFAIK.

Sent from my D6633 using Cruisers Sailing Forum mobile app

[Dockhead]

Originally Posted by DeepFrz

Just realize that this thread was started by someone who has a "Class A Receiver".

I noticed that too, but bit my tongue

Sent from my D6633 using Cruisers Sailing Forum mobile app

[weavis]

I remember when a Class A receiver was anything that could pick up Radio Caroline.....

[CarinaPDX]

Originally Posted by Paul Elliott

But I do not like seeing someone who uses the transponder nomenclature being called ignorant for doing so. That's just not right -- for a number of very good reasons.

I agree - and I didn't write anything like that, although others did.

Greg

[rwidman]

Originally Posted by shawndear

..........Due to your statement you obviously have had no formal training or are so arrogant that you think you can make up your own rules and then bully people and sound so confident that you know what you are talking about when in reality you know nothing about it. This is wrong as you are perpetuating ignorance among newbees and also failing to know the basic rules of the seas.

It's pretty arrogant to call someone else arrogant.

[rwidman]

There was a time when our soon to be Ex President was considering a regulation that would have required an AIS transceiver on every boat. Yes, not just commercial boats, not just boats over a certain size, but every boat. Presumably, even Uncle Bubba's duck hunting boat. Apparently, this was in the name of 'homeland security". The government would be able to track all boats at any time.

Talk about clutter and confusion.

Apparently, someone pointed out how stupid this proposal was and it was withdrawn.

[weavis]

I think we all need to have a sleep or a coffee and walk away from this discussion for a while.

A return to civility would be very welcome...

[leftbrainstuff]

Originally Posted by tanglewood

When you consider all the perceived clutter and nuisance cased by all the boats with Class B AIS, consider what the situation would be if all those same boats had Class A AIS. We would have exactly and precisely the same clutter issue that exists today. So it really has nothing to do with Class B, but only with the proliferation of AIS.

Also regarding filtering, every device I've worked with allows for filtering out targets that are moving less than some threshold speed. To me that's a sensible and useful filter if you want to remove icons from your screen. It completely nullifies any argument about moored boats still transmitting AIS.

Filtering based on Class B vs A is arbitrary. You might as well filter out boats with blue hulls, or boats with Rocna anchors.

The issue of clutter is not a fault of AIS. The whole goal is to ultimately have all vessels transmitting and receiving AIS data.

Two options are available to deal with clutter:

1) zoom in or filter out sectors
2) categorize by threat or proximity or both

Both the above have been part of military threat detection systems for decades. AIS has yet to evolve. Humans are having to be the threat detection discriminator. As a species we're easily overwhelmed by too much data.

Ultimately our onboard systems will use AIS, radar, mesh networking to automate the tracking and alerting of threats.

AIS has not matured enough for this evolution to begin. Let's not class AIS as useless.

As for transponder versus transceiver. Those are just semantics with different meanings in different contexts. AIS is both a sensor and effector. So is radar, vhf, etc.

[SV DestinyAscen]

Argue over the proper noun that doesn't change the underlying issue being discussed re whether sensory overload and predicted human response is a problem.


I don't trust the casual boaters to diligently switch AIS to receive mode/anchor/off - class B should be programmed to switch to a "stationary" mode automatically that still broadcasts AIS position but not underway so all receivers can plot it as stationary if it is in say... Within 60 degrees of the large vessels heading. Class A shouldn't be able to completely filter out class B, but be able to filter out class B within certain parameters like astern, no chance of collision due to speed and heading and distance rings.

[Paul Elliott]

Originally Posted by SV DestinyAscen

Argue over the proper noun that doesn't change the underlying issue being discussed re whether sensory overload and predicted human response is a problem.


I don't trust the casual boaters to diligently switch AIS to receive mode/anchor/off - class B should be programmed to switch to a "stationary" mode automatically that still broadcasts AIS position but not underway so all receivers can plot it as stationary if it is in say... Within 60 degrees of the large vessels heading. Class A shouldn't be able to completely filter out class B, but be able to filter out class B within certain parameters like astern, no chance of collision due to speed and heading and distance rings.

If I understand you, all these features currently exist. Class-B broadcasts include speed data. Most collision alarm systems calculate threat using course/speed vectors (not just range). I believe the main problem is that ships at sea set the alarms to go off when another vessel gets (or will get) within a couple of miles.

These settings are obviously totally inappropriate for use in a harbor situation. When the only other AIS vessels are also large ships, these are few enough that the alarms can be muted ship-by-ship as they occur. When there dozens or hundreds of smaller boats with AIS, it is virtually impossible to mute the alarms as they trigger. Thus the complaints. And thus the reason for better alarm processing.

[SV DestinyAscen]

I don't think class B currently switched to not underway even if you're making 0 knots?

I'm thinking basically an automstically enforced anchor mode.

I've been through Singapore before AIS and I can only imagine what it must be like. Human factors design and engineering has never been a strong nautical focus. Really need to improve signal processing to avoid sensory overload.

[Paul Elliott]

Originally Posted by SV DestinyAscen

I don't think class B currently switched to not underway even if you're making 0 knots?

I'm thinking basically an automstically enforced anchor mode.

I've been through Singapore before AIS and I can only imagine what it must be like. Human factors design and engineering has never been a strong nautical focus. Really need to improve signal processing to avoid sensory overload.

Unlike Class-A, Class-B doesn't send "navigational status" ("under way", "at anchor", etc.) In any case, I would be reluctant to have the software put much faith in this data, since it is human-entered and I've seen way too many cases where a ship "at anchor" is actually underway at 18 kts. This data isn't reliable. Position, course, speed, and rate of turn (not available with Class-B) are what we want for collision avoidance alarms. Fortunately, these are all automatically provided.

I totally agree that this is a human factors problem. Over time things will improve.

[Sea Q]

West coast BC Canada
A full AIS A & B was the best investment I have done in the last 10 years
Great for entering the busy Vancouver Harbor
Great for navigating between all the islands and ferry routes
It a must for our 90 foot pleasure craft and greatly takes the guess work and many surprises away from navigation.
Only once I was surprised in the Sydney area coming around a corner only to find a frigate in mid channel with its AIS turned off which got my heart a pumping.
Great tool in these waters