ADS-B Showing me as traffic

I searched but couldn't find any info specific to my installation
Over the past 2-3 weeks I am seeing traffic directly on top of my location. I've been flying with my current equipment for the past 5+ months with no issue. This only seems to happen in my local airspace, Grand Rapids Michigan. The system also switched to TIS over the same timeframe in the same area. I've sent an email to

[email protected]. Currently waiting for feedback.

I did contact Dynon, they believe it's an issue with the local ATC.

Dynon TT22 (latest SW)
GTN 650 (GPS/WASS BOARD 5.0)

I know there is a later GTN 650 version but according to Garmin 5.0 is fine for ADS-B compliance.

Has anyone else noticed the same issue? Any info would be helpful

Thanks
Gary

Me Too!

I just had that happen with an aircraft we upgraded. All settings are confirmed correct but my "selfie" followed me around, occasionally off by -100 ft, the whole test flight. It threw traffic alerts constantly.

I'm on the west coast (KDVO) so there might have been a new software release pushed onto the FAA's network that "fixed" things.

I would guess you are seeing both ADS-b and TIS traffic when you show ghostng like that.

Ghosting

Jerry
I agree, just not sure if there is anything I can do about it.

Gary

I've had phantom traffic (me) appear on the Dynon Skyview and throw out a traffic alert warning. It usually happens shortly after I make a quick turn or change altitude. It isn't something easy to reproduce, so it must be some sort of software issue either on the ground or in the SV box. There should be a way to filter this by simply looking at the N-numbers of the targets when it happens.

Level flight

Bruce,
My ghosting happens in straight and level flight. Last Sunday I flew from Mackinaw Island to my home airport near GRR. Everything worked fine until until I entered GRR airspace. I used to have a Garmin 327 with TIS traffic so I kind of know when I used to start picking up traffic prior to ADS-B.

Just frustrating getting the warnings non stop.

GaryK said:

Jerry
I agree, just not sure if there is anything I can do about it.

Gary

Click to expand...

The only thing you can do is disable the TIS output into yor EFIS. My Trig TT31 has a feed to my EFIS I can disable, but I choose to leave it feeding and have learned to just overlook that traffic. It's amazing how litle TIS feed there seems to be. Just around large terminal areas.

Me Too

Hi Gary,

I'm over at 3GM, and while en route to 13C (Lakeview) this morning I had the same thing occur. Flying behind a newly installed G500 and G750 in my father's Arrow we repeatedly got traffic warnings at our own position. It has happened multiple times now.

If you come across any answers I'd be eager to hear what they might be.

Best,
Ethan

RV8iator said:

I would guess you are seeing both ADS-b and TIS traffic when you show ghostng like that.

Click to expand...

SkyView does not process both ADS-B and TIS-A traffic at the same time. This is not a TIS-A + ADS-B issue.

bruceh said:

I've had phantom traffic (me) appear on the Dynon Skyview and throw out a traffic alert warning. It usually happens shortly after I make a quick turn or change altitude. It isn't something easy to reproduce, so it must be some sort of software issue either on the ground or in the SV box. There should be a way to filter this by simply looking at the N-numbers of the targets when it happens.

Click to expand...

This makes the assumption that the N-Number or ICAO address are available to the system.

Not all ground radars are Mode-S. If you are in a Mode-C environment, the ground radar has no idea of your ICAO address or your tail number. This target gets sent over to the ADS-B ground station, which can see you via your ADS-B output, and does know your ICAO/N. However, in the beginning, it has no idea if two close targets, one from radar and one from ADS-B are the same plane, or two planes about to collide. Eventually, the ground station sees them do the same thing for long enough, and decides they're the same, and merges them. Before that, it can't tell your radar signature is you, so it uplinks it with no N-number and a random ICAO address, so your EFIS can't just filter it out with simple logic. Your EFIS could do the same correlation, but do you want it to wait to warn you about a traffic threat (one that can collide within 20 seconds) until it's really, really, really sure it's not you?

Even in a Mode-S environment, it's my understanding that many systems cannot transfer ICAO addresses between one another and thus the ADS-B ground stations still only get the lat/long/altitude for a target and must do the correlation that way, not via ICAO address.

The radar systems also have some logic on their tracking. They're designed for en-route planes, not aerobatic or even just a lot of maneuvers. Thus, do a loop, tight turn, stall, etc, and the system may say "I'm not sure which plane is which" for a while and go back to the dis-associated dual targets.

This is all stuff the FAA is aware of and keeps improving.

It's also possible that a ground radar is mis-calibrated. We've seen this happen in places where a ground radar is not adjusted for mag var, so the radar target and ADS-B never associate with one another since they are always on different tracks, but close to one another. So if you notice this suddenly happening in a place where it didn't before, it is worth reporting it to the FAA.

--Ian Jordan
Dynon Avionics

Ghosting

Great thread. "Ghosting" began last week as a regular thing with my Dynon ADSB Out/In while flying in the MLI area after years of being a rare happening. I have been meaning to check the archives here and at Dynon. Thanks Dynon for the update and info on how the system operates.

Ghosting

Ian,
Thank you for the detailed response. Since I'm only having it happen in my local area I'm thinking it's a local ATC issue. Not sure who I would contact to give them the heads up.

I'm hoping to get a response from the avionics check email address to confirm my system is working properly.

Thanks
Gary

Hey Gary, just for a data point, I get it a lot in the GR area and not so much away.

I've had the same thing happen with my G3X system while flying around Columbus, OH a couple weeks ago. Happened several times while maneuvering in the area. Vocal warnings and on the screen, same altitude.

Same thing on my Highlander

Flew my Highlander tonight and had the same issue with ghosting.

SportSX GRT GPS
Trigg T22
Sky Radar

Must be a local GRR issue

I did hear back from the FAA on my RV10, the ADS-B report indicated everything is OK.

Gary

Ghosting

I fly out of KPIA and have has this ghost issue over the last 2 weeks as well on my Skyview panel.

To follow up with this, we talked to the FAA and our collective data did help them identify an issue in the WI/MI area. They are working on resolving it. It is on the FAA side, not the airborne equipment side.

If you are seeing this consistently outside the WI/MI area, please do let us or the FAA know.

--Ian @ Dynon

Thanks Ian,

Had it again Last Wednesday about 20 miles south of Grand Rapids (GRR) and Last Friday about 15miles NE of Grand Rapids.

Ghosting

I've had me as traffic several times about three weeks ago, in the northern Illinois area, out of KDPA. Talked to Garmin and they also indicated it as an FAA issue, noted particularly in the mid-west. Shortly after talking to them, it has not happened again on about 10 flights since them - breaking in a new I/O-390X, so flying a lot. So, maybe they have fixed it.

Incidentally, for those not aware of it who have ADS-B out already, the FAA has a neat service where they will send you a very comprehensive report on how well your ADS-B out is performing. A little disconcerting though when you see the detail records they are keeping on your flights....

FAA did respond

The ghosting problem I had disappeared a couple of weeks ago. Just received this email from the FAA, glad to hear they are working through the bugs.




Mr. Kremers,

Thanks for contacting the FAA. We investigated and found the ground system was incorrectly sending TIS-B data to ADS-B equipped aircraft. The issue was fixed. Let us know if you're still experiencing the issue.

Surveillance and Broadcast Services (SBS)

Problem Report
Date: 10/22/15 10:15PM
Tail Number: N100JV
Name: Gary Kremers
Aircraft: Vans RV-10
Avionics: Trig TT22 with Garmin GTN 650
Location: Grand Rapids ATC
Description: Local time (6:15PM). Ghosting of myself showing up as traffic directly over my position. The problem seems to be only in the GRR ATC airspace. I have been getting the ghosting for the past 2 - 3 weeks. I also noticed it again Sunday morning 10/25/2015 around 10:00 - 10:30 am in the same aircraft and within the GRR airspace

Ghosting on ADSB

Another FAA response on this one. As Dynon suggested - I sent problem report to FAA back in Oct. Got a reply today. Evidently they are addressing these. The note I received this AM:

"Mr. Williams,

"Thanks for contacting the FAA. We investigated and found the ground system was incorrectly sending TIS-B data to ADS-B equipped aircraft. The issue was fixed. Let us know if you're still experiencing the issue.

Surveillance and Broadcast Services (SBS)

Problem Report
Date: 10/22/15 2:15PM
Tail Number: N533E
Name: Keith Williams
Aircraft: Vans RV-12
Avionics: Dynon ADSB In. Dynon ADSB Out (Mode S, ES) GPS position source Dynon GPS250.
Location: Near KMLI
Description: Traffic warning showing traffic superimposed on my aircraft (at location and altitude of my aircraft)."

Happened to me for 300NM

Did a flight 12/12 from SBA in southern CA to CXP and my "traffic alert" followed me for the entire flight. I tried resetting each Skyview in flight, independently of course. Reset the ADSB and transponder with no luck. The target was consistently on top of me, and had several audio warnings. Very annoying. The traffic alert finally went away when I switched from an assigned code to 1200. Have flown that route a few times, and this is the first time I've seen that.

Called Dynon and was referred to this thread.

Who should be contacted at the FAA or ADSB system to look into this?

Edit: found an online form on FAA site, and filled it out.