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hasse_A · 15-12-2017, 13:20

We are on the hard in Chaguaramas, Trinidad. 300 meters away from us there is another boat on the hard in the boat yard next to ours and they have an active SART patronizing us with the alarm constantly on.
I have tried to set OpenCPN to ignore it but it does not seem to want to do that. Maybe this by design.
It's probably not a big deal as when we are launched and get a few miles away it will not be received, but it would nice if you could ignore it.

rgleason · 15-12-2017, 14:26

SART are supposed to be recognized and responded to.

At this point I am unaware of a way to disable the alert as annoying as it may be.

Perhaps there is something in here.
https://opencpn.org/wiki/dokuwiki/do...ons:ais:sart&s[]=mob#after_mmsi_crew_member_sart_is_deactivated

Perhaps filter out !AIVDM that out under Options > Connections then see the input filter.

cagney · 15-12-2017, 14:56

Hasse

Try Options->Ships->MMSI properties.
Create new entry for the offending MMSI an tick "Ignore this MMSI".
Should work - I hope.

Thomas

hasse_A · 15-12-2017, 18:43

Quote:

Originally Posted by cagney

Hasse

Try Options->Ships->MMSI properties.
Create new entry for the offending MMSI an tick "Ignore this MMSI".

Thomas

Yes, this is exactly what I had done but this is no solution. With time the SART
has created hundreds of waypoints and routes. About one every minute.

rgleason · 16-12-2017, 12:17

I guess the SART call takes precedence and is not affected by these attempts, which, quite frankly is as required.

I guess the only way to prevent it is to try to filter it out or turn off the AIS and DSC VHF!

Can't you just turn off AIS?

hasse_A · 16-12-2017, 12:28

Quote:

Originally Posted by rgleason

Can't you just turn off AIS?

Of coarse I can, or turn off OpenCPN all together but then I will not see any AIS transmitting ships.

This is obviously a false alarm and as such it is dangerous in the sense that when you ignore it you may also ignore any other alarm as well. Either by shutting things off or not realizing there is a valid alarm when the speaker is yelling all the time.
My opinion in this mater is that it is better to shut down the false instance of an alarm than all alarms.

reflectionsv37 · 17-12-2017, 03:09

I agree there should be a way to ignore a false SART alarm or one that is so far away that you can't respond.

We seem to get a lot of these in SE Asia and sometimes they go on for days. Depending on where you are they can be 40 miles away. It's really annoying having that alarm screen pop over over your chart that you have to keep clearing.

And these false alerts are dangerous. I was in a big commercial harbor a couple of years ago when one of these went off about 30 miles from the harbor. It went on for hours. I noticed that most of tankers and freighters that were at anchor started turning off their AIS units.

It would be nice if we had an easy way to turn an individual SART alarm off. Either permanently or for a certain amount time that you could specify.

**chris07732** · 17-12-2017, 05:54

Warning thread drift coming: Can you guess what triggered their SART alarm? Do all AIS transmitters have that feature? Are all SARTs picked up by AIS?

hasse_A · 17-12-2017, 06:27

Quote:

Originally Posted by chris07732

Warning thread drift coming: Can you guess what triggered their SART alarm? Do all AIS transmitters have that feature? Are all SARTs picked up by AIS?

I do not know what triggered the SART. We saw the distance and angle to the alarm and tried to pinpoint the boat but as it was on the hard with lots of boats there we gave up finding the actual boat.

The SART is not transmitted by AIS transmitter. It is a special device for transmitting emergency alert.
We have those in our life vests and these are seen by OPCN.
(They have a test mode where the target turns up green in stead of Red)
They can also be a separate device.
I have not checked if the test alarm can be turned of in OCPN but could do that if you want.

cagney · 17-12-2017, 07:41

The "Ignore MMSI" check-box should really work for AisSARTs as well, so I'll treat this as a bug.
Hopefully it can be fixed during the next beta test series, that should not be to far away.
I have entered this in the Tracker:https://opencpn.org/flyspray/index.p...s&task_id=2312
Thomas

hasse_A · 17-12-2017, 08:48

Unfortunately I did not record the SART transmission but I could activate one of my own and do a recording of that. This will of course be a test alarm but it should work as well.

Had a quick look at the code and it seems like SART an DSC alarms always gets detected. I have the latest OCPN official release set for debugging so I could test this later.

This is in the AIS_Decoder.cpp but I am not sure if the target is supposed to get filtered out in an earlier stage yet.

// SART targets always alert if "Active"
if( td->Class == AIS_SART && td->NavStatus == 14)
this_alarm = AIS_ALERT_SET;

bcn · 17-12-2017, 10:16

some test data from a SART manufacturer attached.
MMSI 972210001

rgleason · 17-12-2017, 10:25

Opencpn beta file thingie rguser rgpass. In the nmea directory has many sart recordings.

rgleason · 17-12-2017, 10:57

We have done extensive testing of MOB SART, see how to test at the bottom of this page. The methods for deactivation should work. Please test and advise if they do not. I believe Thomas is right but read the manual please.
Thanks for raising the question and please keep us advised.
https://opencpn.org/wiki/dokuwiki/do...ons:ais:sart&s[]=sart