Author Topic: A really weird one, PAW grabbed traffic and held it.  (Read 18705 times)

Admin

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #30 on: September 16, 2019, 10:12:09 am »
This reminds me of a similar effect  ... Could this be something similar?
it does sound similar, except as you say, it does not appear in the traffic table

thx
Lee

exfirepro

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #31 on: September 16, 2019, 11:26:17 am »
It could of course have been in the Traffic Table initially, then dropped out, but if this was the same (or similar) effect to Ian C’s then its Mode-S would still need to be being received (and visible in the Traffic Table).

Peter

PeterG

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #32 on: September 16, 2019, 12:22:52 pm »
"Hi Peter
I do not see any attachemnts. If they are too large you will need to use dropbox/googledrive or similar
Thx
Lee"

How do you do that?

PeterG

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #33 on: September 16, 2019, 12:24:48 pm »
"Peter,

This is a known phenomenon - if you replay PAW track files on PAW, it treats the track data as if it was ‘live data’ and if it is also receiving external data from it’s antennae, it will parse (combine) this and pass the combined data to the Nav Display. I don’t think this is what Geoffrey and the others are experiencing though as the initial reports are of apparently latched aircraft ‘in flight’ not during replay."

It was the same for me crossing the channel.

exfirepro

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #34 on: September 16, 2019, 01:21:30 pm »
"Hi Peter
I do not see any attachemnts. If they are too large you will need to use dropbox/googledrive or similar
Thx
Lee"

How do you do that?

Hi Peter,

Dropbox is a ‘free’ file storage and transfer utility provided you keep storage within a 2Gb limit.

You can download the Dropbox ‘App’ from your ‘App Store’ or from https://www.dropbox.com/en_GB/

Once you have done this you copy the files / photos you want to transfer to a folder inside your Dropbox, then select that folder and...

On a PC right click on the relevant Dropbox folder and select ‘Copy Dropbox Link’ then paste the link into an email or post it on here.

On iPad or Android device click on the relevant Dropbox folder, select the ‘Share’ button and share by email or create a share link then post the link on here.

Hope this helps.

Regards

Peter R

SGS66

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #35 on: September 16, 2019, 02:03:09 pm »
Lee,
Are you saying that it is a waste of time setting horizontal/vertical filters in PAW CONFIG when using SD ?
Phil

Admin

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #36 on: September 16, 2019, 02:06:44 pm »
Lee,
Are you saying that it is a waste of time setting horizontal/vertical filters in PAW CONFIG when using SD ?
Phil

All the EFB packages I have seen, have the ability to set their own filters, SD, EVFR, AirNavPro etc.
The Horiz/Vert filters were specifically added for those tools which do not have filters, I know skymap is one of those, but cannot recall the others.

It seems to cause confusion, we have had calls where users say 'I have set the SD filters to X, but not seeing traffic', and then we see that they have made adjustments in PilotAware, in effect causing a first stage of filtering before even reaching SD

I am surprised to see the posting of traffic at a distance of 0 for the other PilotAwares, this needs investigation, and I am wondering if it is somehow related to the filters being set.

thx
Lee
« Last Edit: September 16, 2019, 02:08:56 pm by Admin »

GeoffreyC

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #37 on: September 16, 2019, 08:02:20 pm »
Hi Lee

I’ve had an experience of “latched” traffic on playback.   I very rarely play previously recorded tracks but I needed to look at this one, but when I played it back, fast forwarding to the interesting bit, I found that a ground station and another plane had got “latched” to me.

Couldn’t work out how to attach the file to a pm so uploaded to box and sent you a link.

Cheers Geoffrey

Hi Geoffrey
Thanks for this, I loaded this into aircrew, and I do not see any latched traffic, are you only able to see this when you perform playback via SD ?
...
Can you indicate a time I should look at ?

Thx
Lee
Hi Lee,

Until I 'discovered' aircrew on the weekend I was using PAW to playback the traffic.   I was fast forwarding the playback up until when I was transiting through Stansted TMZ and out the other side.  I FF'd (up to 16x I think) to get to roughly the right place and ended up with latched traffic including a ground station and another plane that was a bit behind and above me.  Here's a video of the playback on PAW https://photos.app.goo.gl/JD1YQKRuhnxWV4P36

When I play back in aircrew it doesn't show any traffic that I don't expect it to.

Geoffrey
« Last Edit: September 16, 2019, 08:08:48 pm by GeoffreyC »

exfirepro

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #38 on: September 16, 2019, 08:12:53 pm »
Hi Geoffrey,

Now I’m confused, so to confirm. We’re you seeing the ‘latched traffic’ during the flight itself or just during playback via PAW onto SD?

Regards

Peter

GeoffreyC

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #39 on: September 16, 2019, 08:15:25 pm »
Does GCECL also have a transponder in addition to PilotAware ?
if so do you know the manufacturer ?

Quote
Some screen shots and traffic captures below.  Interestingly GCIJO and GCIGG are both appearing as zero km away, they were flying with me but not that closely!  GCECL who was also with us is reported as 52km away.
This is more interesting. I notice you have vertical/horizontal filters selected. This is only really intended for systems such as skymap which does not have filters available, in SD, it has its own filters. So I am wondering if something screwy is happening with filters applied.

Thx
Lee
GCECL has a transponder plus PAW,  as does GCIJO.  GCIJO is a Funke.  I *think* GCECL is a Trig but I can check if you want to know.

I checked the screen shots I took of my PAW config and I have 'display all' for horizontal display range and '+/- 2000ft' for vertical range.   I probably set it to this for when I  used to use the PAW Radar screen to filter out overflying commercial jets,  and hadn't changed it since moving to Skydemon over a year ago.   No issues to take it off now.

Geoffrey

GeoffreyC

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #40 on: September 16, 2019, 08:19:35 pm »
Hi Geoffrey,

Now I’m confused, so to confirm. We’re you seeing the ‘latched traffic’ during the flight itself or just during playback via PAW onto SD?

Regards

Peter
Hi Peter,  sorry for the confusion.

I don't recall any evidence of latched traffic on the flight on 2nd August,  but when I tried to playback the track on PAW I definitely did get latched traffic.   Here's a link to the video of the playback https://photos.app.goo.gl/JD1YQKRuhnxWV4P36 and you can clearly see another plane and a ground station following along with me.

Quite separately, yesterday, I experienced multiple latched traffic, in flight.  Screen shots of skydemon and the PAW traffic screen attached yesterday.   Most of the planes stayed latched all the way through the journey but some appeared and disappeared en route.

Geoffrey

exfirepro

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #41 on: September 16, 2019, 09:49:44 pm »
Hi Geoffrey,

Thanks for that. I’m not convinced that the planes were latched*, but there is no doubt with the Ground Station, though as I said in my earlier post above, that wouldn’t be unusual if you were replaying a PAW Track file and receiving the local Ground Station ‘live’ via your PAW antenna at the same time.

* In your video, D-KLUB for example could easily have been following you on a parallel track.

Hopefully Lee can make more sense of what is going on, but he needs the track files from original flights (IIRC Track Replay creates its own files containing any combined ‘live’ traffic from during the replay).

Regards

Peter

GeoffreyC

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #42 on: September 16, 2019, 10:40:46 pm »
Hi Geoffrey,

Thanks for that. I’m not convinced that the planes were latched*, but there is no doubt with the Ground Station, though as I said in my earlier post above, that wouldn’t be unusual if you were replaying a PAW Track file and receiving the local Ground Station ‘live’ via your PAW antenna at the same time.

...
Regards

Peter
Hi Peter,

You’re right to be sceptical of course, and when I first saw the playback I too thought I was being followed, but the plane behind and the two in front all stay exactly the same distance and height displacement from me, even when I climb or turn.
Some of this was similar to what happened live on Sunday, planes exactly same position horizontally and vertically separated, and as I mentioned I believed that g-cecl was infringing airspace when it wasn’t (photo of this in the folder from yesterday).

There isn’t a ground station at Sandy when I was playing this back although there is one about 4 miles away en route.

One other thing to add, this latched traffic on replay wasn’t a one off.  It happened several times with slightly different traffic positions depending on how long I ran with fast forward.  I did try no fast forward but I think the same happened.

I’ve sent Lee the track file, and replaying on aircrew doesn’t show any of this traffic.

Geoffrey

exfirepro

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #43 on: September 17, 2019, 09:10:56 am »
Good Morning Geoffrey,

Thanks for the additional feedback. Please understand that I’m not doubting your reports in any way. I am extremely concerned by the proliferation of reports of ‘latched aircraft’ and am just trying to understand what is going on and help try to find an explanation.

During early testing as part of the initial development of PAW Replay (back when there were only 4 or 5 PAW Ground Stations in existence), we realised that when tracks are replayed on PAW with the antennas in place, any traffic being received ‘live’ by PAW during the replay combines with the track file and gets shown on the Nav System display as if it is part of the original track file. The only way to avoid this was to pull the 1090 SDR (close by ‘high power’ 1090MHz signals can still be received through the pigtail without the antenna in place) and disconnect the P3i antenna to prevent reception of any local direct (or rebroadcast) P3i. Ideally of course, to protect the transmitter, the P3i transmit side should be turned off by selecting ‘Aircraft Type’ to ‘Base Station Rx’ in ‘Configure’ before removing the P3i antenna.

This results in ‘clean’ PAW track replays. The same thing is achieved by downloading the original Track Log and running it in Aircrew Replay as there is of course then no opportunity for ‘live’ traffic to interfere.

In your case, although at the limit of range ‘on the ground’ at 4 miles, it is still ‘possible’ that the nearby ground station is the one that is following you on the replay. I can’t of course comment on the other aircraft, though I wonder if they are also in some way linked via the Ground Station. Lee is obviously much better placed than me to determine this via track analysis, (without the necessary Linux skills and equipment I can only do this by manually examining the track logs which takes an inordinate amount of time) which is why he needs original track logs from everyone experiencing this phenomenon.

Together we will get to the bottom of what is going on and Lee will be able to devise a ‘fix’.

Best Regards

Peter

PeterG

Re: A really weird one, PAW grabbed traffic and held it.
« Reply #44 on: September 17, 2019, 09:51:38 am »

"Hi Peter,

Dropbox is a ‘free’ file storage and transfer utility provided you keep storage within a 2Gb limit."

Thanks for that

Attached is the dropbox link.

As in the other cases above, when the track is run through Aircrew, these aircraft don't appear, so I would guess there is something in the interface with SD that is causing this.

https://www.dropbox.com/sh/7bxoasdpgkbulsj/AADyKTJ6SkAecyre2YoWBkofa?dl=0



Regards

Peter