Primarily for general aviation discussion, but other aviation topics are also welcome.
#1692323
I'm running SkyDemon (latest version) with Sky Echo 2 release WiFi 0.2.13 and ADSB 2.6.6. I see plenty of Gatwick CAT traffic plus a few helicopters and GA transmitting ADSB.
I operate out of Shoreham but have yet to see any bearingless targets in the last half a dozen flights.
I have 'Show Bearingless targets' ticked in SkyDemon.
Anyone know if this is a config issue?
#1692362
The SkyEcho 2 does not support bearingless targets as you know them from Flarm and PilotAware.

You will therefore not see any.
#1692399
Tim Dawson wrote:The SkyEcho 2 does not support bearingless targets as you know them from Flarm and PilotAware.

You will therefore not see any.


Interesting.... The SkyEcho datatsheet says "Mode C/S proximity detection and alert" but in the installation guide it is not clear whether this is implemented yet. The change list says:

REV B 8/28/18 Mode C/S Bearingless Targets, DoCCApproval

But the text in section 5 says:

Mode C/S Transponderproximity detection (Beta NOT YET ENABLED). Leveraging the 1090 MHz receiver, the SkyEcho 2 is able to produce a bearingless proximity alert indicating the presence of a nearby aircraft with a Mode C or S (but not ADS-B) transponder.

So is this a case of the function not yet there, or is it something in the GDL90 protocol that means SD does not receive a usable warning ?
#1692632
This news announcement states bearingless Mode C/S is a ‘base capability’ :
https://uavionix.com/news/uavionix-anno ... nspicuity/

“SkyEcho 2 base capabilities include:
Mode C/S transponder proximity detection for detection of aircraft not equipped with ADS-B OUT“
Implies the device can do it.


Tim Dawson wrote:The SkyEcho 2 does not support bearingless targets as you know them from Flarm and PilotAware.

You will therefore not see any.
can you help explain this in more (technical) detail please Tim?
#1692663
Bearingless targets are a feature provided by Flarm and PilotAware. Those devices pass us the aircraft id, altitude, vertical speed, estimated range (guesswork but based on signal strength; the user can learn to interpret the ring size changes over time) and even callsign.

SkyEcho doesn’t have anything like that. Its only offering is to send us the altitude of a mode C/S return as it comes in. No vertical speed, no range (estimated or otherwise), or even an aircraft id. I declined that offering.
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#1692680
I have not physically used PAW but I do struggle with the concept of coloured rings of varying size for mode A/C/S bearingless targets and it seems that others are now finding it difficult to quickly interpret what is being displayed to them using the coloured ring idea.

I still use my quite brilliant Zaon MRX which guesstimates the distance and vertical height as a proper distance number which is logical to interpret and understand.
Yes it is not a perfect estimate of distance but I know to ignore anything that is above 2miles away and if I see the distance reducing in either plane, regardless of being visual with the traffic or not, I can adjust my flightplath accordingly. It is so easy to understand!
The Zaon obviously cannot be replaced as the company no longer exists so a replacement will sooner or later will be an issue for me. PAW is the current obvious choice but I want numbered distance not coloured rings!!
What I would like to see is someone reverse engineer a Zaon MRX?...Please? I just don't know why some has not done this. I paid around £300 for it 10years ago and it is worth its weight in gold.
It is fag packet sized, sits on the glareshield and is simplicity itself and it tells me what I want to know about other bearingless transponder equipped traffic .
#1692685
Shoestring Flyer wrote:I have not physically used PAW but I do struggle with the concept of coloured rings of varying size
I largly dont pay attention to the rings - I have audio alerts. This keeps my eyes looking out!

I used to have a Zaon MRX, it eventually failed, exhibiting false aircraft alerts to that were not there (it was actually my aircraft). When it worked, it was useful, but Skydemon with PAW and audio alerts for bearingless and all the other traffic thats presented (gliders by OGN, ADSB etc) , is an order of magnitude better. :D

Tim Dawson wrote:Its only offering is to send us the altitude of a mode C/S return as it comes in. No vertical speed, no range (estimated or otherwise), or even an aircraft id. I declined that offering.
Thank you for explaning Tim, I can certainly see why you did that. The Skyecho 2 bearingless limitation certainly wasnt aparent to me - until now. :?

Really glad I have a PAW :thumright:
#1692695
Ridders wrote:
Really glad I have a PAW :thumright:


As I get more used to Rosetta I find it more and more useful. I did a candidate's Skill Test today and, being a thermally and sunny day, there were contacts aplenty. I'm starting to get more confident in the bearing less thing too.
#1692698
Shoestring Flyer wrote:I have not physically used PAW but I do struggle with the concept of coloured rings of varying size for mode A/C/S bearingless targets and it seems that others are now finding it difficult to quickly interpret what is being displayed to them using the coloured ring idea.

I still use my quite brilliant Zaon MRX which guesstimates the distance and vertical height as a proper distance number which is logical to interpret and understand.
Yes it is not a perfect estimate of distance but I know to ignore anything that is above 2miles away and if I see the distance reducing in either plane, regardless of being visual with the traffic or not, I can adjust my flightplath accordingly. It is so easy to understand!
The Zaon obviously cannot be replaced as the company no longer exists so a replacement will sooner or later will be an issue for me. PAW is the current obvious choice but I want numbered distance not coloured rings!!
What I would like to see is someone reverse engineer a Zaon MRX?...Please? I just don't know why some has not done this. I paid around £300 for it 10years ago and it is worth its weight in gold.
It is fag packet sized, sits on the glareshield and is simplicity itself and it tells me what I want to know about other bearingless transponder equipped traffic .


@Shoestring Flyer ,

I also still have a Zaon MRX, which I started using back in 2009, and which was what persuaded me to pursue the reporting of otherwise 'Bearingless' Mode S (initially), and subsequently Mode C targets with PilotAware. I am therefore also well aware of the limitations of Bearingless Target Alerts, but in view of the high number of aircraft still using Mode C or Mode S transponders, I can see no reliable alternative (at least outside the coverage area of the soon-to-be-released OGN-R Mode-S/3D).

I also fully understand Tim's reticence to act on a mere ' aircraft somewhere at xx altitude' report from SkyEcho, however the type of report provided by PilotAware (and PowerFLARM) and reported on SkyDemon as concentric coloured rings (and in other ways on other Nav Systems) is a different thing entirely.

Firstly, the coloured rings denote degree of risk (or danger) presented by the reported aircraft. The rings DO NOT in any way represent a 'safe zone' or the distance the other aircraft is away from your own. PilotAware does NOT report (or attempt to report) the distance that an incoming 'Bearingless' aircraft is from the user's PilotAware Unit. This was a deliberate decision to reflect the known inaccuracies of trying to reporting distance from signal strength from a massive variety and combination of different equipment, antennas and installations in different (or even similar) aircraft.

PilotAware does, however report the aircraft's 'Hex ID' - usually converted to its 'Reg ID' - to the Nav System, together with the Relative Altitude of the aircraft - derived directly from its transponder response to any RADAR interrogation. It also reports a 'threat level' based on a 3D measurement of the strength of that signal and compared to a predetermined database. This report takes the form of one of 3 threat levels, increasing in importance as the range between the target and host aircraft reduces.

These threat levels are then reported by each Nav system developer in different ways dependent on their preference or taking account of other factors.

In the case of PilotAware's own 'RADAR' screen and Easy VFR, the warning is presented on a coloured banner near the top of the screen, containing the Aircraft details (Reg ID where known - or 'Mode C') and Relative Altitude. The colour of the banner Green, Amber or Red denotes increasing danger and will change if the user and target aircraft continue to close range.

With SkyDemon, the same information is presented, but as a coloured ring, centred on the User's Aircraft, with the Aircraft Details (Reg ID where known - or 'Mode C') and Relative Altitude displayed at the 12 o'clock position on the ring. The colour of the ring - Green, Amber or Red - again denotes increasing danger and will again change if the aircraft continue to close range, but in Sky Demon's case the rings also get smaller as they change colour to emphasise that the range is closing.

In all of the above cases, the 'sensitivity' i.e. the 'range' at which you start to receive bearingless target warnings and at which each subsequent increase in 'Danger Level' is triggered is 'User Selectable' in PilotAware.

In all cases, the operation is both simple and effective - especially if you also have the PilotAware Audio Warnings enabled. All you need to do when you receive a warning is focus your initial lookout based on the reported relative altitude and be prepared to consider appropriate avoiding action based on the relative altitude reports if the initial threat level increases significantly .

Hope this helps.

Regards

Peter
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#1692702
@exfirepro ..

Thanks for explanation.
A couple of points though:-
It isn't the accuracy of the distance that matters two hoots really . It is the PAW concept of changing coloured rings that is the issue. It wouldn't matter if the numbers were 4321 decreasing as the traffic got closer. It would make more sense to my, probably feeble, brain.
Also to me the coloured rings getting smaller as the traffic gets closer is backwards to my way of thinking! Surely, as in real life, as traffic gets closer it should be displayed larger not smaller?

@ridders
Traffic warning by audio I am afraid does not appeal to me one bit either. Somebody jabbering in my ear would certainly annoy me in a busy circuit.
#1692704
Tim Dawson wrote:Bearingless targets are a feature provided by Flarm and PilotAware...
SkyEcho doesn’t have anything like that. Its only offering is to send us the altitude of a mode C/S return as it comes in. No vertical speed, no range (estimated or otherwise), or even an aircraft id. I declined that offering.

I completely empathize with your situation Tim
We have spent the best part of 3 years learning how to best handle the plethora of data including Mode C/S/ES
Issues which need resolving are
- Filtering Mode-C returns from common emitters of Mode-S, ADS-B, PAW and Flarm
- Filtering Mode-S returns from common emitters of ADS-B, PAW and Flarm
- Coalescing iterative Mode-C altitude changes from the same aircraft
- Filtering of local Mode-C/S returns
This is not trivial, and consumes considerable compute power to be able to manage, filter and present this data in a meaningful manner

This does not even go part way to solving all the problems, for example - how to handle the aliasing of Mode-A Squawk codes versus Mode-C altitude codes, there are many times when a Mode-A squawk appears as though it is a Mode-C altitude, we have clever techniques to exclude these from consideration.

Providing the RAW Mode-C altitude data is next to useless I'm afraid, as 3 years of painful engineering have taught us.

Thx
Lee
#1692711
Shoestring Flyer wrote:@exfirepro ..
Thanks for explanation.
A couple of points though:-
It isn't the accuracy of the distance that matters two hoots really . It is the PAW concept of changing coloured rings that is the issue. It wouldn't matter if the numbers were 4321 decreasing as the traffic got closer. It would make more sense to my, probably feeble, brain.

I think the intention of the ring is to indicate an enclosing area to indicate proximity.

Also to me the coloured rings getting smaller as the traffic gets closer is backwards to my way of thinking! Surely, as in real life, as traffic gets closer it should be displayed larger not smaller?

hmm discuss ....

One last point about the Zaon, this was an inspiration to the work we did in adding bearingless targets - however it has one big drawback which is the duplication of target data
The Zaon is not able to decode emissions of ADS-B, PilotAware or Flarm
in which case if you have an aircraft fitted with a Mode C/S transponder, and also capable of emitting on or more of the following :-
- ADS-B
- Flarm
- PilotAware

It will still report the above emitters as Bearingless targets, even though the same aircraft will be plotted on your NAV device with its position. It has no way of knowing that they are one and the same aircraft - so you may spend your time searching for a bearingless target, which is already plotted on your screen.

Thx
Lee
#1692712
Shoestring Flyer wrote:It isn't the accuracy of the distance that matters two hoots really . It is the PAW concept of changing coloured rings that is the issue.


It's not the PAW concept as such, this is the Sky Demon depiction. Other mapping programs do it differently as mentioned for EasyVFR above. I like the rings as I'll explain below.

Shoestring Flyer wrote:It wouldn't matter if the numbers were 4321 decreasing as the traffic got closer. It would make more sense to my, probably feeble, brain.


I haven't seen the recent depiction of bearingless on the PAW's own radar display - it may be possible to add this in if it's not already there. However colours seem logical, for 3 being green, 2 being yellow, 1 being red.

Shoestring Flyer wrote:Also to me the coloured rings getting smaller as the traffic gets closer is backwards to my way of thinking! Surely, as in real life, as traffic gets closer it should be displayed larger not smaller?


It's supposed to depict a rough range. It's around your aeroplane on the Sky Demon map screen. With a big green ring, it means the contact could be over a wide area, not necessarily within the area depicted within the ring, but over a large area of sky. With a medium sized yellow ring it means it's getting closer. With a small red ring, it means it's within the closest band, and probably quite close, within a small area around your aeroplane.