Satelite AIS.

[El Pinguino]

Ben,
It seems even though I have cancelled I still get the 14 days free trial , it simply doesn't move on to a paid conscription, so shoot me the name of your parents' boat and I'll see what it comes up with.
Ping

[Snowpetrel]

Very interesting Ping, she is New zealamd maid. Also since you have the trial see if you can wayne on Ambler. He is up Tonga/fiji way.

Sent from my SM-G930F using Cruisers Sailing Forum mobile app

[El Pinguino]

No probs Ben

The third one is a US flag boat , Lady Arisha, doing an east bound passage to Panama or wherever....

[El Pinguino]

And if you really want to know what Wayne and Kathy are up to......

[JPA Cate]

Some of you guys are pretty experienced cruisers. Why do you want other people to know where you are? other than rendezvousing with friends, of course.

Ann

[El Pinguino]

Originally Posted by Ann T. Cate

Some of you guys are pretty experienced cruisers. Why do you want other people to know where you are? other than rendezvousing with friends, of course.

Ann

I don't for one... two many creditors/ex-lovers/angry husbands trying to track me down

However I am fascinated by the technology.

I don't think too many will be stumping up the $3000+ a year to go down the sat ais track however...

It would appear that if you run an AIS transponder they know where you are wherever you are.

The solution is just to run your AIS in receive mode only unless you feel the situation demands that you should be seen.

Receive only... with a good loud alarm.... would do the job for most good watch keepers .

That said ... put position reports into yotrep once a day and everyone knows what you are up to and where you have been... this is about 6 years worth of past tracks.. I really do need to get out more

[Snowpetrel]

Originally Posted by Ann T. Cate

Some of you guys are pretty experienced cruisers. Why do you want other people to know where you are? other than rendezvousing with friends, of course.

Ann

Yeah, very true, I tend to like to be pretty independant, but I have no problem with others knowing where I am. I usually arrange a radio sched once a day. For safety reasons, but if I had AIS like this it might not be needed.

It is nice for the folks back home to be able to track progress, and I am enjoying being able to snoop on where my folks are!

But like Ping I am interested in the technology and the capability of our equipment.

I am pretty impressed (and slightly concerned) with the detail so far. Seems like it is reasonably viable even with a weak 1w class B. It probably helps a lot that the southern hemisphere is pretty quite boat wise. Seems like the system has limited capacity and in heavy traffic the weak class B signal struggles to get priority. I did hear some rumors of a new S-ais protcol that excludes class B. But also some new class B tech that will boost s-ais reception. Interesting field.

I have been researching antenna types. It might be that the high gain antennas dont work so well for S-Ais due to them concentrating the signal around the horizon. Maybe a short low gain antenna might work better.

For what its worth my folks have (I think) a 1/4 wave ground dependant antenna without the ground plate. At the moment it is very inefficient giving only 5 miles of reliable range. It will be interesting to see what happens when they install the ground plane. Antenna theory is a deep rabithole! Anybody who actually knows what its all about care to comment?

[lamadriver]

There is no such thing as S-AIS. its just low orbiting sat that monitors the VHF spectrum the Class B and class A xcvr use.


Every RCC in the world has has access to this info and its nothing new ( not that it not cool). Its pretty much been around and available since the advent of AIS, but not to the consumer.

the question is as more serives provide AIS info for free will less people invest in devices like a delorme.

I have a Go and it has a been a good device for me and I use a app that my friends can tack me with .


LD

[StuM]

Originally Posted by Ann T. Cate

Some of you guys are pretty experienced cruisers. Why do you want other people to know where you are? other than rendezvousing with friends, of course.

Ann

I use my Inreach when doing deliveries and other passages so that wives/SOs/friends and other interested parties who are not on board can see how we are going and when we are likely to arrive at destinations/intermediate locations. Much better than having them left in suspense for days at a time.

[hoppy]

Is Marinetraffic web browser working for you at the moment? I see no targets at all and I've checked my filters and tried a different browser. My iPhone app is working fine.

In a couple of days I should be in an anchorage in Greece that is a internet AIS "blackspot" and it will be interesting to see if I can be found among the thousands of other vessels in the region.

BTW I just noticed this on the marinetraffic S-AIS give us lots of money page

Note that Satellite AIS tracking may be less effective for vessels equipped with Class B AIS transponders due to their lower transmission power.

[Littlechay]

Originally Posted by Ann T. Cate

Some of you guys are pretty experienced cruisers. Why do you want other people to know where you are? other than rendezvousing with friends, of course.

Ann

I don't care who knows where I am, usually. Occasionally I may take a short cut though; but that is why I have class B, I can switch it off

However friends, family, blog followers, and armchair adventurers do like to see where we are and that is what we use Yotreps for.

[Snowpetrel]

Originally Posted by El Pinguino

And if you really want to know what Wayne and Kathy are up to......

Thats pretty impressive from a tracking perspective, though it looks like a lot of the area is covered by terrestrial AIS. It sure looks lile they are having a heap of fun!

What sort of tracking interval have you noticed on the S-ais tracks? I seem to be getting anything from 1.5 hours to 10 hours or more on the folks boat, but their dodgy antenna may, or may not be helping.

Thanks for putting your cruising kitty on the line in the name of idle curiosity. I figured I would forget to cancel and get stung for the insane amount of money they want. Now I know it can be canceled right away and still used I might give it a go when they head off up the coast.

[Snowpetrel]

Originally Posted by lamadriver

There is no such thing as S-AIS. its just low orbiting sat that monitors the VHF spectrum the Class B and class A xcvr use.


Every RCC in the world has has access to this info and its nothing new ( not that it not cool). Its pretty much been around and available since the advent of AIS, but not to the consumer.

the question is as more serives provide AIS info for free will less people invest in devices like a delorme.

I have a Go and it has a been a good device for me and I use a app that my friends can tack me with .


LD

Hi LD, thats interesting that RCC's have been using this for years. I guess it really helps them coordinate assets in the area quickly.

I dont think at this point it will really effect the takeup of satelite systems like the Delorme. The Delorme offers a lot more features, and two way comms and is good value for anyone spending much time offshore. That doesn't want to invest in satphones or pactor modems.

I see this more as a incidental bonus to having AIS, and a useful backup to know about.

Do you guys have AIS on the Helecopters? If so it would be interesting to know what sort of range its getting with the extra altitude. It would make SAR pretty easy if you could find an AIS signal from 100nm out.

[El Pinguino]

If you read the link at #11 it seems that sat monitoring of Epirbs started in about 2010 when they had one sat up.... that looks pretty new at my age.

To quote a bit of it

'Each satellite continually receives AIS signals from all ships in its footprint (1000‟s of ships !)
• Signals stored in satellite memory
• Memory data is encrypted & replayed as satellite passes over next ground receiving station
• Encrypted data is fed to the Data Processing Centre where AIS signals are extracted and forwarded to authorized users
• Soon will have multiple satellites for faster coverage (3 plus 3 more)'

Mucking around with it the lag for most yachts seems to be 12 to 16 hours although it say you can set up instant tracking for, I think, a total of 15 in your 'fleet'.

Not surprised to read at #40 that 'Note that Satellite AIS tracking may be less effective for vessels equipped with Class B AIS transponders due to their lower transmission power.' considering that there is nothing in its design spec that involves stuff in space.
That explains why some tracks I am seeing have big gaps in them.

[El Pinguino]

I've just had a bit of a look at big ships in the North Pacific and North Atlantic...pretty much everything seems to be at 15 to 16 hours and some out to 19 hours so expect there is a bit of filtering going on there.