Aircraft is not transmitting its callsign

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EGPE3
Posts: 8
Joined: Sat Jul 01, 2017 9:26 am

Aircraft is not transmitting its callsign

Post by EGPE3 » Tue Apr 10, 2018 2:11 pm

Several aircraft appear in list view with no call sign, and show text "Aircraft is not transmitting its callsign" in the detail area when clicked on. These are usually aircraft whcih are not tranmitting position data and hence don't appear on the map. But interrogating the feed directly shows that they ARE transmitting callsign data. So why does it not appear in the list? Is there a decoding setting somewhere I need to change?

I found this old thread reporting what may well be the same problem - callsigns appear in report but not in the list view, but there were no replies:
viewtopic.php?t=548

kiwikieran
Posts: 36
Joined: Sat Jan 20, 2018 8:50 pm

Re: Aircraft is not transmitting its callsign

Post by kiwikieran » Thu Apr 12, 2018 4:46 am

I am presuming you have checked the JSON to see the Callsign?

EGPE3
Posts: 8
Joined: Sat Jul 01, 2017 9:26 am

Re: Aircraft is not transmitting its callsign

Post by EGPE3 » Thu Apr 12, 2018 12:36 pm

I don't know what a json is, sorry, but I have checked my own raw feed reports (I'm also using FR24 software).

At the moment, for example, VR list view is showing:

Reg. Callsign Route FL V.Speed A/P Alt. Speed Hdg. A/P Hdg. Type Operator ICAO Squawk
G-JEDW DH8D Flybe 400B04
G-MAJL JS41 Eastern Airways 40098E

And the FR24 tracked aircraft feed is showing:

ModeS: 40098E Callsign: EZE52Y
Lat: N/A
Long: N/A
Alt: 9325ft
SQW: 7774

ModeS: 400B04 Callsign: BEE8HC
Lat: N/A
Long: N/A
Alt: 24000ft
SQW: 7663

So the VR display is not picking up callsign, altitude or squawk, all of which are on the FR24 listing. VR is given the same RAW data feed as the FR24 software.

kiwikieran
Posts: 36
Joined: Sat Jan 20, 2018 8:50 pm

Re: Aircraft is not transmitting its callsign

Post by kiwikieran » Thu Apr 12, 2018 9:50 pm

Is the aircraft showing on the map in VRS or the side panel? FR24 is showing the postilion as missing which would suggest MLAT.

kiwikieran
Posts: 36
Joined: Sat Jan 20, 2018 8:50 pm

Re: Aircraft is not transmitting its callsign

Post by kiwikieran » Fri Apr 13, 2018 1:17 am

Please ignore last reply, have you unchecked ignore position less flights and if merged feed ticked the MLAT box in VRS?

EGPE3
Posts: 8
Joined: Sat Jul 01, 2017 9:26 am

Re: Aircraft is not transmitting its callsign

Post by EGPE3 » Fri Apr 13, 2018 11:03 am

Yes, these will be aircraft that don't send out position data.

It is a merged feed, and the "ignore positionless flights" box was already unticked. I've now ticked the MLAT box for each of the three feeds making up the merge, but it's not made any difference.

I've noticed that the list also frequently fails to display the squawk, even for aircraft transmitting position and call sign data. I'd wondered if there is something wrong in the decoding stage, but apart from staring blankly at the raw feed decoding page, I haven't a clue what to do - I just use the recommended settings.

EGPE3
Posts: 8
Joined: Sat Jul 01, 2017 9:26 am

Re: Aircraft is not transmitting its callsign

Post by EGPE3 » Fri Apr 13, 2018 5:50 pm

I may have solved the problem.

I've reconfigured VR to accept a "base station" feed rather than a "raw" data feed from the receivers, and call signs, altitudes and squawks now appear. This presumably means there is something going wrong in the Virtual Radar treatment of the "raw" data feed in that it's not able to extract the same information that the receiver can extract and provide in the "base station" feed. It would be nice to know why this is, rather than just sweeping the problem under the carpet, but the technicalities are beyond me!

kiwikieran
Posts: 36
Joined: Sat Jan 20, 2018 8:50 pm

Re: Aircraft is not transmitting its callsign

Post by kiwikieran » Fri Apr 13, 2018 7:37 pm

Glad to hear you have possibly resolved this issue.
The rebroadcast feed on ADS-B Exchange also has the same issue.

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