Author Topic: Traffic Page - own aircraft not always showing  (Read 3957 times)

Gary Nelson

Traffic Page - own aircraft not always showing
« on: January 05, 2020, 10:00:07 pm »
I paste below 3 x screen shots of my PAW traffic page (as well as having PAW, I also transmit ADSB via a squitter from my Funke transponder) On one of them my aircraft (G-NILT) is shown at the top highlighted red and showing Mode CSA-- but no details of aircraft. On another it is shown at the top highlighted grey with reg "G" and showing Mode ---P--U and confirming it is a EV-97 Eurostar. On the third it is not showing at all. Any idea why the discrepancies?
« Last Edit: January 06, 2020, 05:52:18 am by Gary Nelson »

PaulSS

Re: Traffic Page - own aircraft not always showing
« Reply #1 on: January 06, 2020, 12:55:30 am »
What trigger is used by your transponder to tell it it's flying? I would suggest, with the red report, that as you're on the ground and stationary the transponder wouldn't be transmitting and, therefore, no ADSB Out through the extended squitter.

It is quite likely that I am talking complete nonsense but I've set up my EFIS (which talks to my transponder) so that above XXX its and XXX RPM it knows it's in the air and to squawk away. Your transponder may have some sort of air switch and do the same. Of course, none of that may be true and you may have had the transponder blurting out its stuff on the ground, while stationary and all the above is a waste of bandwidth  ;D

Gary Nelson

Re: Traffic Page - own aircraft not always showing
« Reply #2 on: January 06, 2020, 05:32:21 am »
As far as aware, my Funke transponder is either on or off, manually by my switching it on/off. Regardless, the red report is showing me transmit CSA i.e. ADSB out. So I think the question remains why the discrepancies. Hopefully someone will know?

Admin

Re: Traffic Page - own aircraft not always showing
« Reply #3 on: January 06, 2020, 08:02:26 am »
Hi Gary
Where was your plane located when you took these screenshots ?
Also, what firmware revision is your funke ?

Did you temporarily change the ID of your PAW to see your plane ?
If so, what was the setting you changed it to ?

Thx
Lee

Admin

Re: Traffic Page - own aircraft not always showing
« Reply #4 on: January 06, 2020, 08:37:56 am »
Hi Gary,

I have taken a look at some of our tracking data.
I can see you emit PAW, FLARM and ADS-B.
The ADS-B data seems to have gaps especially I have noticed a flight on Jan/4th your ADSB was not seen until 15:24 just East of Banbury
Your FLARM and PAW was seen From Wellesbourne on the runway at 15:16
All 3 last saw you at 15:55 just East of M25/M1 at 700ft, I presume you were too low to be tracked

I am most concerned that your ADSB was not seen until 15:24 - this indicates some issue :-(

Thx
Lee

Gary Nelson

Re: Traffic Page - own aircraft not always showing
« Reply #5 on: January 06, 2020, 02:56:52 pm »
Dear Lee

Thank you for your 2 posts.

1.     I am indeed meant to be emitting PAW; FLARM and ADSB. I have had a Flarm LX mouse for a couple of years but
        have never seen an elusive "F" in the PAW traffic screen, only gliders rebroadcast via the Uplink. I think you need to
        be only a couple of km or less and so perhaps that is why. Good to know you could see my Flarm emitting (I assume
        via the online OGN network where I have seen it as well).

2.     Re not seeing my ADSB until 15.24 on Saturday 4th Jan. I had taken-off from Wellensbourne Mountford at 15.16 and
        so that is only a gap of 8 minutes. I do normally switch it on before take-off but I think on this occasion I may have
        already been in the air, so hopefully not an issue.

3.     The last view you saw at 15.55 at 700 feet was my coming into land at Plaistows (3 miles north of Elstree) having left
        Wellensbourne Mountford at 15.16.

4.     My Funke transponder TRT800H-OLED is using version 5.3

5.     I only ever keep my PAW Flight-ID on G-NILT and HEX-ID on 406C23 and would never change either.

6.     The red traffic screen shot (showing my microlight) was taken 29th July and I was still on the ground at Plaistows for
        a short flight a few minutes later over to Bovingdon active airfield. The grey traffic screenshot (showing my
        microlight) was on 4th January at 15.46 and 30 minutes into the above referred 39 minute flight from Wellensbourne
        Mountford to Plaistows (I was about 4 miles west of Bovingdon). The third screenshot (not showing my microlight)
        was a minute earlier at 15.45

So re point 6 above, I am still perplexed why the 3 snapshots of my PAW traffic screen are different when it comes to my microlight. Any further assistance would be very much appreciated

Gary

« Last Edit: January 06, 2020, 03:04:16 pm by Gary Nelson »

Admin

Re: Traffic Page - own aircraft not always showing
« Reply #6 on: January 06, 2020, 04:54:26 pm »
Hi Gary

Were these snapshots taken on your PAW, or somebody else's PAW ?

I cannot understand how your PAW is displaying yourself, this should be filtered when the address matches, which is ICAO=406C23

I had not realized snapshot 1 was July last year - are you running the same software release today as you were Jul/29 ?

Actually, thinking on this - FLARM is displayed but is 'greyed out' meaning, it is not sent to a NAV device.

I think what you are ultimately asking, is "can I see the ADSB out of my funke", is this correct ?
If so, you need to temporarily change the HEX-ID in your PilotAware, lets say 406C23 to F06C23
Now have a look to see if you see your own transponder, if so - all is good, set the HEX-ID back to 406C23

PilotAware may need to be some distance from your transponder (30ft)  as the transponder RF is so powerful it can swamp/overload the PilotAware receiver

Thx
Lee

Gary Nelson

Re: Traffic Page - own aircraft not always showing
« Reply #7 on: January 07, 2020, 12:40:50 am »
Hi Lee

I confirm the 3 snapshots  were all my PAW.

To clarify, I am not asking about ADSB. I want to know why the 3 PAW traffic screenshots I posted are all different in that (1) the one from July (likely pre PAW software upgrade)  shows my microlight at the top highlighted red (2) the one at 15.46 a few days ago on 4th Jan showing my microlight at the top greyed out and (3) the one at 15.45 same day (4th Jan) but a minute earlier, not even showing my microlight i.e. they are all different??

Hope you can help.

Gary

exfirepro

Re: Traffic Page - own aircraft not always showing
« Reply #8 on: January 07, 2020, 09:29:01 am »
Hi Gary,

I have been following this thread, but haven’t commented previously as I didn’t want to interrupt what Lee was trying to explain. I hope he won’t mind me commenting now.

The ‘short’ answer is that the traffic screen is merely  a ‘snapshot’ of what is going on inside PAW at any particular point in time, viz for example the ‘Mode-C’ processing you will regularly see constantly changing at the bottom of the table (if you have Mode CS enabled) where the unit is working out whether a received signal is a Mode-C ‘altitude’ transmitted as part of a Mode-S or Mode-S/ES packet, or a transmission from a separate ‘Pure Mode-C’ transponder). What the Traffic screen is showing is whatever it is processing at that point in time. It was never meant to be ‘used’ by pilots as a ‘traffic list’ - especially not in flight.

It used to be the case that ‘Ownship’ always appeared at the top of the Traffic Table - especially if running Mode-S or Mode-S/ES - and was then filtered (by Hex ID) and not passed to the Nav System for display.

As the software developed, however, and it was decided to add detection for Mode-C, as well as integration of directly received FLARM (from an external FLARM device), then later uplinked FLARM Traffic from the OGN-R network and more recently uplinked Positional ‘Mode-S/3D’  - the additional processing required appears to have removed the option for the software to display ‘Ownship’ at the top of the screen as before. See comments in this earlier recent thread...

http://forum.pilotaware.com/index.php/topic,1771.0.html

I hope this helps clarify the situation.

Regards

Peter

Admin

Re: Traffic Page - own aircraft not always showing
« Reply #9 on: January 07, 2020, 09:40:43 am »
Hi Gary

OK, there are 3 scenarios here lets handle individually
I just tested the latest release and it still shows your own Aircraft ADSB (greyed out) I faked this, by setting my ICAO to a passing airliner

your microlight listed as --P-U was a re-broadcast, in which case when it disappeared one of the following was true
1. your FLARM was not detected by a groundstation
2. your PilotAware was out of range of a groundstation.

Regarding your missing ADSB (which you are not concerned about) - this is definitely saturation, and sometimes you are lucky you may see your own ADSB, but in general, you need some distance between the transponder and the receiver

Hope that helps
Thx
Lee

« Last Edit: January 07, 2020, 09:42:52 am by Admin »

Gary Nelson

Re: Traffic Page - own aircraft not always showing
« Reply #10 on: January 07, 2020, 11:24:04 am »
Dear Lee and Peter

1.    I think you are saying due to saturation (caused by the proximity of the avionics on my microlight to each
       other) it will be rather lucky if and when "ownership" ever shows on my PAW Traffic screen in the Mode column as a
       CSA---- i.e. ADSB but that when near a ground station I should at least likely see ownership in the Mode column as
       ---P--U or even ----F-U.

2.    Just to confuse things, I have a traffic screenshot (as pasted below) dated 1st June 2019 at 8.56am when I was
       about 2,000 feet and 3 miles south east of Booker, en-route to the coast. You can see I am highlighted red and the
       Mode column showing CSAP---. So I am still a bit confused as to the "ownership" variations I am seeing







« Last Edit: January 07, 2020, 11:35:16 am by Gary Nelson »

Admin

Re: Traffic Page - own aircraft not always showing
« Reply #11 on: January 07, 2020, 11:36:58 am »
Hi Gary
Quote
1.    I think you are saying due to saturation (caused by the proximity of the avionics on my microlight to each
       other) it will be rather lucky if and when "ownership" ever shows on my PAW Traffic screen in the Mode column as a
       CSA---- i.e. ADSB but that when near a ground station I should at least likely see ownership in the Mode column as
       ---P--U or even ----F-U.

I would need to check but actually, ----F-U I think indicates it is FLARM Uplink, and ---P-U indicates an MLAT uplink
either way - they are uplink data from a groundstation

Quote
2.    Just to confuse things, I have a traffic screenshot (as pasted below) dated 1st June 2019 at 8.56am when I was
       about 2,000 feet and 3 miles south east of Booker, en-route to the coast. You can see I am highlighted red and the
       Mode screen showing CSAP---. So I am still a bit confused as to the "ownership" variations I am seeing

OK, I think this is actually CSAP- this is the previous release, there was no distinction of uplink
So this is the rebroadcast of your FLARM, and ModeS/3D was still under trial and not available to all.

Thx
Lee

exfirepro

Re: Traffic Page - own aircraft not always showing
« Reply #12 on: January 07, 2020, 03:36:35 pm »
Gary,

Your reply is along the right lines, but my interpretation of Lee's comments is more specific than that. I think Lee is saying is that your 'Ownship' - i.e. a report of your own aircraft - should NEVER appear in the traffic table on your own Pilotaware except where your FLARM is received and rebroadcast by a Ground Station.


Lee,

As you know, I don't often disagree with your comments, but Gary's last screengrab from 1st June 2019 (when he would still have been running version 20180520) clearly shows his 'Ownship' at the top of the table, with the Mode reporting as 'CSAP- ', i.e. Mode-S/ES plus PilotAware - as has always been the style of report for this type of installation. I see nothing here that would indicate a rebroadcast. I am a bit confused by the Reg showing as G - though I'd be hard pressed to explain this as a 'Ground Uplink' as the Mode reporting is totally incorrect for a ground uplink (even at that time).

Gary's screenshot is almost the same as mine from June 2018, when I was running Pi3B+ Engineering software version 20180515 (which I posted over in the other thread and have re-posted below) - and is the last screenshot I have showing 'Ownship' on my Traffic Table, despite the hundreds of screenshots I have taken since - hence my assertion that something changed in the software between versions 20180520 and 20190621 which now prevents 'Ownship' being displayed in the Traffic Table (except perhaps due to a 'hiccup' via a rebroadcast).

Sorry to question your advice, but something clearly isn't as it is being reported.

Best Regards

Peter


Gary Nelson

Re: Traffic Page - own aircraft not always showing
« Reply #13 on: January 12, 2020, 10:15:28 am »
I would be interested if Lee responds to Peter's last post.

To possibly confuse further, on 11th Jan, myself and another plane (G-IMPS) flew together. The owner having just fitted Pilotaware. You can see from below that the screenshot of my own Traffic screen at 3.46pm shows both myself G-NILT in grey and G-IMPS in red but his screenshot at 3.47pm only shows me G-NILT in red but not him at all !
« Last Edit: January 12, 2020, 10:17:39 am by Gary Nelson »

Admin

Re: Traffic Page - own aircraft not always showing
« Reply #14 on: January 12, 2020, 10:43:16 am »
I would be interested if Lee responds to Peter's last post.

To possibly confuse further, on 11th Jan, myself and another plane (G-IMPS) flew together. The owner having just fitted Pilotaware. You can see from below that the screenshot of my own Traffic screen at 3.46pm shows both myself G-NILT in grey and G-IMPS in red but his screenshot at 3.47pm only shows me G-NILT in red but not him at all !

Hi Gary,
I think this is consistent with what I said previously
If the transponder is close to the receiver, it is likely to saturate and not get detected.
This is not black and white, it is a grey area, so depending upon whether the receiver is overloaded or not will result in the detection of your own transponder

I think the reason you are seeing your own aircraft is because you are emitting FLARM, this is being rebroadcast to you, which is why you see
406C23 G ---P-U (PilotAware via Uplink)
your own transponder is not reported, otherwise you would see CSAP--U, which incidentally is exactly what is seen from G-IMPS, so the other PilotAware is seeing Your transponder (CSA), your PilotAware (P), and also your Flarm (---P-U)

Regarding the Grey out, this means it is filtered and not sent to the navigation device - which is correct behavior, as this is your own aircraft

Hopefully makes sense ?

BTW, you are getting great coverage, you are picking up 2 Ground stations FA52F7 and F41F21, so getting good rebroadcast of Mode-S/3D and Flarm/OGN trackers, G-IMPS appears to have 1 G/STN do the antenna installations differ very much ?

Thx
Lee