AIS not displaying CG SAR Helo

[TSB240]

We have a locally based SAR helio

I noticed today that my Onwa ais plotter did not show this on its display.

However Opencpn running on a wifi enabled tablet clearly showed the helicopter using the ais output from the Onwa.

I will report this to the UK agent as I think it is an important safety feature to have on all ais plotters.

I don't believe I have a filter on the received sentence that prevents it being displayed on the Onwa. Unless you can advise me otherwise!

Interestingly I lost the track of the SAR helio at about 80 nm range as it was approaching the Isle of Man.

 

[Refueler]

Interesting but I'm a little confused .... so bear with me ...

You say the SAR is not shown on the ONWA display ?

But you say OPENCPN display does show it ? Basically that you are using the AIS data from the ONWA fed to your OPENCPN ....

mmm interesing ... I would suspect some filtering to your ONWA display ??

Which ONWA unit are you using ?

 

[KompetentKrew]

I guess it must be ignoring this vessel type.

OpenCPN has a log file or a window you can open to view NMEA sentences, so you could check what vessel type it's been shown as or if there are any other irregular details.

 

[st599]

If it has altitude, OpenCPN is decoding message type 9, SAR aircraft, Onwa isn't. AIS Standard Search and Rescue Aircraft Position Report (Message 9) | Navigation Center

Else, does it also show AIS SART and MOB alarms? They're also a special subclass of a class A message with an additional broadcast safety message containing text data.

 

[TSB240]

Thanks for your replies and advice
FYI it is an Onwa KP 27A class b+ without WiFi.

I confirm I'm using info derived from the ONWA nmea 0183 wired output and transmitted to the tablet by an add on wifi unit. The android tablet uses the latest version of open cpn.

I might have to wait a couple of days before I get another opportunity to check all the advice given.

Clicking on the displayed helio in opencpn I get ID as SAR, mmsi, speed and direction but no altitude!

I have noticed that the Onwa shows some base stations but have not checked if Opencpn has more.

 

[Refueler]

I cannot say for certain .. but if the ONWA is using Passthru on the NMEA ... then it would be passing on the whole NMEA incl AIS to your WiFi unit ...

The ONWA unit may for its own display filter the NMEA sentences ...

I assume you contacted Alan at AVES ? I'm sure he will have or get an answer for you.

 

[PaulRainbow]

SAR and some other messages are relatively new, so perhaps a software update for the Onwa ? As said, contact Alan at Aves.