ADS-B Traffic target problem

Any DA40 related topics

Moderators: Rick, Lance Murray

User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

ADS-B Traffic target problem

Post by smoss »

I recently upgraded to the GTX 345r transponder, with all the ADS-B in out/TAS600 integration, etc. (report to follow in install experience thread), and am having an issue with some of the TIS-B targets (non-ADS-B equipped in radar area) showing a blank identifier field with it. Usually, these TIS-B targets show with only target symbol and relative elevation, and no identifier field attached, but sometimes, I get a whole mess of them showing with a dashed out identifier field. Attached pic shows one (+11 in middle of screen). Sometimes I see none, yesterday, had 10-15 on my screen at once. Is this behavior others have seen? Also, it does not appear that the other ADS-B equipped planes are showing up to me in "ground mode" (brown symbols). I was sitting in run-up area next to another plane that showed up as ADS-B target with identifier as soon as airborne, but did not show up on the ground. Any thoughts?
Attachments
IMG_1116_edited-1.jpg
Last edited by smoss on Mon Oct 01, 2018 9:47 pm, edited 1 time in total.
Steve
DA40 XL
User avatar
DaveS1900
3 Diamonds Member
3 Diamonds Member
Posts: 65
Joined: Sun May 06, 2018 1:09 am
First Name: Dave
Aircraft Type: DA40
Aircraft Registration: N521DD
Airports: I74 Urbana Ohio
Has thanked: 5 times
Been thanked: 28 times

Re: ADS-B Traffic target problem

Post by DaveS1900 »

Steve,
We have the GTX 345r also in our DA40. On occasion a target with no details is shown (TAS600) and a target with direction and altitude (ADSB) is shown. The no-details target jumps around a bit and after a couple of minutes merges into the ADSB target. I take it to be that the TAS600 is trying to work out if its target is the same as the ADSB target. Eventually it figures out that the targets are the same airplane and merges them. It may be that your TAS600 is having a hard time determining distance and direction which leads to the "extra" targets.
Dave
User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

Re: ADS-B Traffic target problem

Post by smoss »

Nope, the targets are real. They are TIS-B targets that will show up on iPad via Scout/foreflight and show as TIS-B if tapped on. Sorry, forgot to attach pic to first post--added it.
Steve
DA40 XL
User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

Re: ADS-B Traffic target problem

Post by smoss »

Dave, do you ever see the identifier field with all dashes like in my pic?
Steve
DA40 XL
User avatar
CFIDave
5 Diamonds Member
5 Diamonds Member
Posts: 2678
Joined: Wed Nov 07, 2012 3:40 pm
First Name: Dave
Aircraft Type: OTHER
Aircraft Registration: N333GX
Airports: KJYO Leesburg VA
Has thanked: 231 times
Been thanked: 1473 times

Re: ADS-B Traffic target problem

Post by CFIDave »

smoss wrote:Dave, do you ever see the identifier field with all dashes like in my pic?
No, I've never seen that before. (However lately I've spent more time flying DA40 NG models with G1000 NXi and GTX345R, rather than Legacy G1000 DA40s retrofitted with the GTX345R.)

I'm wondering if the target aircraft displayed with dashes is using a UAT ADS-B transponder that the owner switched to "Anonymous Mode" for privacy -- something that's unavailable with our ADS-B 1090ES transponders.
Last edited by CFIDave on Tue Oct 02, 2018 1:25 pm, edited 1 time in total.
Epic Aircraft E1000 GX
Former DA40XLS, DA42-VI, and DA62 owner
ATP, CFI, CFI-I, MEI
User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

Re: ADS-B Traffic target problem

Post by smoss »

Dave, they are not ADS-B out aircraft, they are all Mode C/S targets that are being rebroadcast by TIS-B (as shown using Scout ADS-B in and ForeFlight)
Steve
DA40 XL
User avatar
DaveS1900
3 Diamonds Member
3 Diamonds Member
Posts: 65
Joined: Sun May 06, 2018 1:09 am
First Name: Dave
Aircraft Type: DA40
Aircraft Registration: N521DD
Airports: I74 Urbana Ohio
Has thanked: 5 times
Been thanked: 28 times

Re: ADS-B Traffic target problem

Post by DaveS1900 »

Steve,
I'll bet those are standard radar targets that are VFR. The radar knows the alt but not the call sign. The radar data gets sent over to the ADSB transmitter which sends the data to you. But no call sign since ATC isn't talking to them.
Dave S.
User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

Re: ADS-B Traffic target problem

Post by smoss »

Agreed, that's what they are, but shouldn't they just display the symbol and altitude, without the extraneous empty field?
Steve
DA40 XL
User avatar
Rick
5 Diamonds Member
5 Diamonds Member
Posts: 1575
Joined: Tue Jul 06, 2010 10:09 pm
First Name: Rick
Aircraft Type: DA40
Aircraft Registration: NONE
Airports: KROA
Has thanked: 107 times
Been thanked: 297 times

Re: ADS-B Traffic target problem

Post by Rick »

smoss wrote:Agreed, that's what they are, but shouldn't they just display the symbol and altitude, without the extraneous empty field?
You would hope so, right? Maybe this particular radar site explicitly sends dashes for the callsign when it's unknown, instead of just leaving it blank, so that's what the G1000 displays?
Roanoke, VA (KROA)
User avatar
smoss
5 Diamonds Member
5 Diamonds Member
Posts: 742
Joined: Sun Dec 12, 2010 12:18 am
First Name: Steve
Aircraft Type: DA40
Airports: KVGT
Has thanked: 57 times
Been thanked: 134 times

Re: ADS-B Traffic target problem

Post by smoss »

That may be. Particularly in Las Vegas I see a ton of them, whereas between Los Angeles and here, don't recall seeing any.
Steve
DA40 XL
Post Reply