Author Topic: Spurious position reading from a/c origin  (Read 1327 times)

neilmurg

Spurious position reading from a/c origin
« on: September 18, 2024, 08:40:44 pm »
Hello again, 'sbin a while. This is ATOM Grid related - right place?
We had a visit today from an AW169 air ambulance. I missed it in flight and checked it via the radar360 playback (which shows helicopters as planes).
a/c was 4074BF G-KSSC. The track shows spikes back to the take off point. Can this be filtered out? Would this affect a PAw detecting the a/c or is it just a ground station artifact?
I thought it looked like the kind of thing you can get with MLAT, but it's ADSB data I think.

Hopefully I've seen something that can be filtered, is new / novel.
Still loving the Rosetta, I carry a spare in case I'm in a poorly equipped a/c...

Regards neilmurg

neilmurg

Re: Spurious position reading from a/c origin
« Reply #1 on: September 21, 2024, 12:00:49 am »
OK, not an insight?
If it's common / well known, could someone tell me what it is and I'll move on.
Otherwise, I'll move on and be slightly less informed.
Cheers guys, a great group
xx

steveu

Re: Spurious position reading from a/c origin
« Reply #2 on: September 22, 2024, 08:04:19 pm »
I looked but don't really have any concrete ideas, last time I saw something like that I was told it was an SDR fault in a ground station, but it could be an ADS-B problem with GPS jamming? Worth checking on another tracking app? It seems fine on planefinder for all flights.

However, the second and third flights on Playback have spikes. I'd be looking at the ground stations or the database...

neilmurg

Re: Spurious position reading from a/c origin
« Reply #3 on: September 22, 2024, 09:08:03 pm »
Thankyou for the reply :)
It has the feel of a database glitch, something is holding on to a value and inserting it in the wrong place. But I've an IT background so there's that bias in my thinking.
Reverting to the take-off position means/reveals something.
Even if the fault can't be traced, it should be possible to exclude the bad datapoint.
Also, could it be at the 360radar display end?
Enough from me
All the best
« Last Edit: September 22, 2024, 09:17:23 pm by neilmurg »