AIS through satellites.

[El Pinguino]

So they are using LEO's?

[GILow]

Originally Posted by El Pinguino

So they are using LEO's?

I think they are mostly Sagittarius.

[El Pinguino]

No bull?

Well that explains everything then....

Lunch? A four'n'twenty... not even a floater... could have put on a black and white beany and eaten it outside in the cold with a bit of tom sauce while watching a vid of Collingwood winning a premiership.. sadly the only vids I could find of the magpies winning a premiership were in black and white ... on tape.... sigh

[StuM]

Originally Posted by El Pinguino

So they are using LEO's?

Yep. Here's a "For Dummies" book which is actually advertising for exactEarth, but it gives a good description of how satellite AIS works.


http://cdn2.hubspot.net/hub/183611/f...ies_E-book.pdf

[Nicholson58]

Originally Posted by SVHarmonie

Sorry... wrong... All you have to do is look at Marinetraffic.com, and you’ll know that AIS broadcasts are pick up by satellite.

There most certainly are satellites that can pick up AIS signals from space. There are several commercial services that sell the resulting data to ship owners. Like this one: https://insights.spire.com/maritime-...api-from-space

AIS signals are line of sight, and satellites most certainly are in your line of sight, and not all that far away. Class A transmitters are easy for the “eyes in the sky”, Class b with lower power transmitters, a bit more difficult.

Oh, Class A transmitters ar 12.5 W and Class B are 2W

The satellite AIS system is wholly separate and quite new. Here is everything you might care to know. (link) SAIS was instituted to track commercial, A class, vessels. It uses a growing number of new satellites to mine the data from boat transceivers. This is a commercial operation selling services to shore based interests such as tracking ones fleet and property. Class B is a more recent addition as the capability to manage the massive data improves. Unless you have onboard capabilities for access to the marine services such as satellite internet this is invisible to the boater.

https://en.wikipedia.org/wiki/Automa...ication_system

Note that the data processed By SAIS from our ship board transmitters is subject to priority and a host of issues. There are places with little or no coverage. This is especially true of shorter range class B signals.

[GILow]

Originally Posted by El Pinguino

...
Lunch? A four'n'twenty... not even a floater...

Are you out of pea soup as well?! I had no idea the situation was so dire in Victoria. Perhaps I shall share some of my hoard in the keel, I think I have around 400 cans... or was that rolls...?

[El Pinguino]

OK....someone has to ask the question....

..
..
..
Is your AIS turned on?

Nothing showing terrestial or celestial this morning..

[GILow]

Originally Posted by El Pinguino

OK....someone has to ask the question....

..
..
..
Is your AIS turned on?

Nothing showing terrestial or celestial this morning..

Bugger!

I think we may have sunk during the night. NOTHING is working this morning. Bl—dy HF is on the fritz, now it seems AIS has gone toes up as well.

Actually, this is weird. I can see the Caspian Harmony here on the plotter, so reception is fine. By why the heck is the Caspian Harmony anchored just past Backstairs Passage?

Voltages are all good, so I’m assuming it’s something to do with satellite angles and your theory about the headland to the north of us.

[El Pinguino]

Originally Posted by GILow

Bugger!

I think we may have sunk during the night. NOTHING is working this morning. Bl—dy HF is on the fritz, now it seems AIS has gone toes up as well.

Actually, this is weird. I can see the Caspian Harmony here on the plotter, so reception is fine. By why the heck is the Caspian Harmony anchored just past Backstairs Passage?

Voltages are all good, so I’m assuming it’s something to do with satellite angles and your theory about the headland to the north of us.

To get the occasional 12 hour break is not unknown... the consistency of your problem is a worry...
Getting back to the Rio Valdivia ( which I dearly wish I could ) ... the two yachts mentioned yesterday... one is now 6 hours.. the other 23 minutes... why is it so when they are only metres apart..... dunno...

Caspian Harmony.. Mejillones to Kwinana.... now that is a seriously long passage... engine trouble? Going north of KI to avoid the weather that is coming along?... again... dunno....

I see MT is offering me free stuff... must check that out later....

[GILow]

Ah yes, there’s some stinking weather coming through, now that you mention it.

I had checked their port of origin... what a forlorn place. And yes, what a long passage.

Not much I can do about the satellite AIS issue until I find somewhere else to park the boat out of terrestrial receiver range.

I am a little hopeful that there’s something odd about American River when it comes to AIS cover. I do seem to remember observing similar behaviour from other boats, and I even telephoned one couple when I lost them on marine traffic, only to have them say they were still in American river after a couple of weeks. I didn’t think much of it at the time, AIS was still very new to me.

[El Pinguino]

You're back!
10 hour old position...
'passenger vessel' ( possibly James Cowell?) showing over at Buick Point 6 hours old........

[GILow]

Originally Posted by El Pinguino

You're back!
10 hour old position...
'passenger vessel' ( possibly James Cowell?) showing over at Buick Point 6 hours old........

Yes, your guess is correct, and Mr Cromwell caused a few grey hairs this morning because I had forgotten to turn off my AIS proximity and TCPA alarms.

I thought we’d broken free of the mooring because I use the AIS unit as a mooring alarm.

Anyway, I am a little frustrated that he turned his AIS off as soon as he got back. I cannot compare our cover over time. But is suspect his is better when it comes to satellites, and may well be Class A given he is a commercial ferry.

[El Pinguino]

Nope, she is Class B... see below

So Mr Cromwell has turned off the AIS so we no longer have a comparison...

Oh well...

I hate to ask the question.... what AIS brand do you have?

On a brighter note... does your ant have a good view of the sky?... no davits or dinghies or stuff in the way? The mast does not count...

[GILow]

I have the Matsutec, which is a bit of an unknown.

But I do know it outperforms a number of boats I know first hand, including boats with the highly regarded Vesper 800. I have a simple comparison, the Adelaide to Port Vincent run, which always has a small gap on cover right in the middle. I’ve compared the gap with a number of other boats and I’m right up there in the top ten percent when it comes to a small gap on the middle.

The antenna is well clear of anything obstructive. It sits to one side of my starboard solar panel on the stern arch, about ten feet above the water.

I suspect that American River is particularly problematic when it comes to height. Cromwell is a tall cat, and I’d say his antenna is at twice the height of mine, if it is the one I think it is.

I do want to put my antenna at the top of the mast, but that’s ANOTHER job.

[El Pinguino]

Bit of thread drift....
Don't knock Mejillones.... I'll give you the drum....I'd far rather be in Mejillones just now than under the lee of Ballast Head .... and I'll wager a gallon of pisco sour to a pie floater you would be as well...
Yes that's my boat in one shot...
Water is normally 'crystal'... was an algea bloom...

PS I wouldn't stress the top of the mast thing...