I have the skyview with the adsb470 module. I receive weather fine. I fly in and near a class b area. Why do i need the SV tansponder adsb out to see traffic? My buddy flying with his ipad and the garmin adsb receiver and no adsb out sees traffic all the time because there are always ga planes with adsb out nearby that are triggering the data to be sent. Is this possible with the skyview? And if not, why not? Some traffic would be better than no traffic. Is there something I'm missing? Thanks.
ADS-B Traffic
- Thread starter jhiggins
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The ground stations do not send up Mode-C or Mode-S targets unless they know about you. Without a transponder, they don't know. While you can sometimes "use" data from other planes, this data is only sent up for a circle 15NM around the plane and +/- 3,500'.
So the issue here is a false sense of security. You might see a plane on traffic behind you and think you're covered, but the ADS-B traffic circle ends behind you and below you so you don't see that airliner right ahead descending at you. In this way, "some" traffic is not better than "all" traffic.
Different companies have made different decisions here, and ours was to not show traffic unless we were sure it was a full traffic picture, and not advertise ADS-B traffic unless we knew we were selling a full solution.
However, if you really want to try it, go into traffic setup and lie to the system and say "Non-Dynon ADS-B OUT ONBOARD" and set it to YES. Just be aware that you will only see a very small portion of GA targets out there, and just because you see one target doesn't mean you can see them all.
So the issue here is a false sense of security. You might see a plane on traffic behind you and think you're covered, but the ADS-B traffic circle ends behind you and below you so you don't see that airliner right ahead descending at you. In this way, "some" traffic is not better than "all" traffic.
Different companies have made different decisions here, and ours was to not show traffic unless we were sure it was a full traffic picture, and not advertise ADS-B traffic unless we knew we were selling a full solution.
However, if you really want to try it, go into traffic setup and lie to the system and say "Non-Dynon ADS-B OUT ONBOARD" and set it to YES. Just be aware that you will only see a very small portion of GA targets out there, and just because you see one target doesn't mean you can see them all.
rfinch
New Member
Assuming the airliner has ADS-B Out, wouldn't you be getting its traffic reports, and thus be covered? Seems the danger is two aircraft without ADS-B Out and thus neither receiving accurate traffic.
Which brings up a question. Aircraft A has a mode C transponder and ADS-B Out, Aircraft B only the mode C transponder. Does Aircraft A get a traffic report of Aircraft B, accurate to whatever a mode C transponder position can do, or no report at all?
- Joined
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In order for an aircraft to get traffic targets, it needs to be ADS-B OUT and ADS-B IN. A properly installed ADS-B OUT system with no ADS-B IN tells the ground station it doesn't have IN, so the ground station doesn't uplink anything.
Almost zero airliners have ADS-B OUT much less ADS-B IN. Latest stats are about 300 airliners out of 8,000, and half of those are UPS Airplanes that fly at night.
Even if they had ADS-B IN, it might be on the 1090 frequency, and we're 978, so you wouldn't even see their targets.
If you have ADS-B OUT and ADS-B IN you see all Mode-C targets to the resolution the radar provides, so you'll see the airliners and all Mode-C equipped GA planes.
Almost zero airliners have ADS-B OUT much less ADS-B IN. Latest stats are about 300 airliners out of 8,000, and half of those are UPS Airplanes that fly at night.
Even if they had ADS-B IN, it might be on the 1090 frequency, and we're 978, so you wouldn't even see their targets.
If you have ADS-B OUT and ADS-B IN you see all Mode-C targets to the resolution the radar provides, so you'll see the airliners and all Mode-C equipped GA planes.
rfinch
New Member
Thanks, a very helpful clarification of how ADSB works.
I was under the impression that if you had full ads-b capability (I have your transponder and ads-b box) that you would receive anything that showed up on radar regardless of whether they had a transponder or not. I also assumed that radar picked up aircraft based upon their radiated signature, not their transponder or lack of. Is this not correct?
RVDan
I love flying!
In some meetings with our local ATC (Potomac approach), they indicated that they don't typically see primary targets, only transponder equipped aircraft.
swatson999
Well-Known Member
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I believe the equipment (consoles) can be configured to either display primary-only targets or not. So they may "typically" only see XPDR returns, they *can* see primaries if they want to.
