Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Miscellaneous
#1861268
If an aircraft is equipped with ADS-B out and Flarm what will another aircraft detect if it is equipped with SE2, SD and a Flarm subscription? Will ADS-B, or Flarm have precedence?

TIA
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By Dave W
FLYER Club Member  FLYER Club Member
#1861272
From experience with some aircraft here that have both, I think it is essentially transparent to you as the detecting aircraft. I think you are shown the aircraft regardless of the source signal, and you don't see a double return.

PS Unlike this FR24 situation where the aircraft has FLARM as well as a Mode S transponder which has been multilat'ed by FR24 ground stations. :D
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By Miscellaneous
#1861291
Dave W wrote:From experience with some aircraft here that have both, I think it is essentially transparent to you as the detecting aircraft. I think you are shown the aircraft regardless of the source signal, and you don't see a double return.

Thanks Dave. I pose the question because that is exactly what I found flying with Nick, who has both. I simply wondered whether it would be his ADS-B, or his Flarm, I was detecting. As long as the other aircraft is detected I don't suppose it matters which. I am just curious as to how it works.
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By Tim Dawson
SkyDemon developer
#1861295
Is the flarm is configured correctly they will both be outputting the same icao 24bit address, so there would be no duplication or conflict within SkyDemon.
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By Miscellaneous
#1861300
@Tim Dawson I am not questioning 2 detections. As I said I only detected one. I was curious as to which would be detected and if there is any difference on what is displayed?

From what you say I'm guessing whether Flarm or ADS-B is detected SD will display exactly the same thing (even from aircraft only fitted with one)?
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By Tim Dawson
SkyDemon developer
#1861311
It’s effectively random which you would actually see on screen, and would depend on the timings of the two transmissions. I can’t remember the frequency of Flarm emissions compared to adsb emissions.
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By Miscellaneous
#1861325
@Tim Dawson thanks. :thumright:

Not that it's relevant to what SD picks up, however I have noticed that another forumite's icon shows on FR24 as an SEP when Flarm is detected and as an airliner when ADS-B is detected. :D
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By ls8pilot
#1861329
Dave W wrote:Sounds like their ADS-B is not set up properly.

Not uncommon with Flarm systems - many Flarm displays are quite granular in their representation which can be a bit confusing - was a bit concerned the other week that a jet was following me closely, till it started thermalling with me!

What is proving useful, esp this year, is the ability to distinguish between paraglider and glider contacts.

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By Shoestring Flyer
#1861330
Tim Dawson wrote:It’s effectively random which you would actually see on screen, and would depend on the timings of the two transmissions. I can’t remember the frequency of Flarm emissions compared to adsb emissions.


Flarm/PowerFlarm is on 868Mhz and ADSB is on 1090Mhz so two different signals being emitted at two different intervals.
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By Dave W
FLYER Club Member  FLYER Club Member
#1861335
ls8pilot wrote:Not uncommon with Flarm systems - many Flarm displays are quite granular in their representation which can be a bit confusing - was a bit concerned the other week that a jet was following me closely, till it started thermalling with me!

Well, yes.

But Misc reported that particular example as showing as an airliner on ADS-B, not FLARM - which correctly showed as SEP.
By Nick
FLYER Club Member  FLYER Club Member
#1861336
@ls8pilot What display do you use for your Flarm? I have not seen those symbols before.
I use a Butterfly V3+M display which I like as it only alerts me to direct threats.
I also have one of my tablets using my PowerFlarm to supply GPS for SkyDemon and that gives me and overall warning but those symbols would be usefull.

Nick
User avatar
By Miscellaneous
#1861347
Dave W wrote:But Misc reported that particular example as showing as an airliner on ADS-B, not FLARM - which correctly showed as SEP.

Indeed, at least I'm 90% sure it was that way round. :D I won't name said forumite, however he may choose to confirm? FTAOD it's not @Nick.