Primarily for general aviation discussion, but other aviation topics are also welcome.
By thegasguy
#1855394
I didn't see ( visually ) that aircraft after the Solent, but I'm pretty sure it didn't loop back as it's usually home for tea and biscuits - as you know.
So, it looks as if the positions on screen are not reliable- that really isn't helpful at all.
#1855396
Regularly see the Spitfires from Goodwood / Biggin / Headcorn en-route and over Seven Sisters / Beachy Head ( and once or twice the Hurricane ) .

Appreciate that instrument panel space in these iconic aircraft is at a premium , but as these aircraft are operated as a commercial operation I feel they should be adopting the concept of EC and be as visible as possible, after all the camoflage paint schemes do a pretty good job of hiding them to the naked eye.

Imagine the amount of public outcry if there was ever to be a incident with any of these aircraft and any other GA within the Class G , especially if it gets revealed that many , private flyers in GA aircraft are enthusiastically adopting lowcost EC devices ........
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By Dave W
FLYER Club Member  FLYER Club Member
#1855397
What you see on FR24, due to their use of multilateralisation ("MLAT") cannot, I think, be taken as any indication at all of SE2 direct reception performance.

Something strange seems to be going on here, but I think using FR24 data to investigate runs the risk of only muddying the waters further.
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By MichaelP
FLYER Club Member  FLYER Club Member
#1855445
Used to have the occasional ghost show up on the screen when flying in a valley, especially a mountain valley.
Could be ground reflections if you’re low enough?
By rdfb
#1855803
The aircraft you think you were receiving bad data from - was this a PilotAware, and someone you know? I'm unclear, but if this is the case, you can probably retrieve the PilotAware's view of its position from its track log, and cross-reference that against your own flightradar24 trace, or alternatively that PilotAware device's log of what it received about your own position.
#1855831
rdfb wrote:The aircraft you think you were receiving bad data from - was this a PilotAware, and someone you know? I'm unclear, but if this is the case, you can probably retrieve the PilotAware's view of its position from its track log, and cross-reference that against your own flightradar24 trace, or alternatively that PilotAware device's log of what it received about your own position.


Hi
The screenshot I posted above was the ground station reception of the broadcast ADSB/DF17
There were are no glitches or jumps in the track, it is smooth and consistent.
This would lead to the conclusion that it is a receiver/display issue I would have thought ?

Do we know if there is any traffic data logging at the SkyEcho2 receiver (or SD) to be able to post-process ?

Thx
Lee
By rdfb
#1855849
leemoore1966 wrote:There were are no glitches or jumps in the track, it is smooth and consistent.
This would lead to the conclusion that it is a receiver/display issue I would have thought ?


I'm no expert but I've seen my phone give me a bad GPS track that appeared smooth and consistent. It was just off by a mile. So I was wondering about the source and if the source logged what it had transmitted.

What I don't follow is the actual setup here - what the sources and receivers were exactly in terms of device and protocol. Depending on the details, my suggestion might not make sense.
#1855862
Flyin'Dutch' wrote:Anything relying on ground stations and re-broadcasts is, per definition, going to be more accurate than a product with a certified chipset which uses direct line of sight transmissions and receipt.

Always.


Why? I genuinely cannot understand why this can be the case.

Surely the device in the aircraft calculates its position from the satellite signals and broadcasts that. The ground stations receive that and retransmit it allowing it to be received by others over a larger area.
Where can the greater accuracy come from?
highfive liked this
#1855985
lobstaboy wrote:
Flyin'Dutch' wrote:Anything relying on ground stations and re-broadcasts is, per definition, going to be more accurate than a product with a certified chipset which uses direct line of sight transmissions and receipt.

Always.


Why? I genuinely cannot understand why this can be the case.

Surely the device in the aircraft calculates its position from the satellite signals and broadcasts that. The ground stations receive that and retransmit it allowing it to be received by others over a larger area.
Where can the greater accuracy come from?


I think there was a note of sarcasm in @Flyin'Dutch' post
**update**
Or was it a mistake now corrected, from more to less

FD you miss the point entirely, this is about the ADSB/DF17 position reports, and whether they are interpreted as correct or not
The ATOM ground station network displays a smooth and contiguous set of position reports for the aircraft in question
The OP reported position jumps of 15 miles when viewed from his SkyEcho/SD Combination

Both airborne and ground based systems would have received identical DF17 position reports

Thx
Lee
Last edited by leemoore1966 on Thu Jul 01, 2021 7:21 am, edited 1 time in total.
By riverrock
FLYER Club Member  FLYER Club Member
#1856005
He was recieving on a SkyEcho 2, so that means direct ADS-B receipt or direct FLARM receipt. As far as I know there aren't any FIS-B over UAT traffic trials going on.

So that means one of:
-failure of 4 mk1 eyeballs
-failure within a recieving / display device
-failure within a transmitting device
-someone is intentionally spoofing transmissions

Let's rule out 1 and 4.
So what we are missing is the registration / details of the ghost aircraft and precise timings so they can be checked back from ground based / other receivers. That will determine if issue is 2 or 3.
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By PaulSS
#1856024
FD you miss the point entirely, this is about the ADSB/DF17 position reports, and whether they are interpreted as correct or not
The ATOM ground station network displays a smooth and contiguous set of position reports for the aircraft in question
The OP reported position jumps of 15 miles when viewed from his SkyEcho/SD Combination

Both airborne and ground based systems would have received identical DF17 position reports


To be honest, Lee, I don't know why you expend so much time and effort trying to help when all you get is snide and unhelpful comments such as FD's.

It's a SkyEcho problem, so let Uavionix sort out. I'm sure they have an excellent track log and diagnosis system and don't need the likes of ATOM stations, Vector and Aircrew getting in the way.

Take it away Ramsey; it will be interesting to see the results of the SE investigation.