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9/15/2015 3:11 PM
 
David wrote:... It also seemed like I had the best traffic coverage that I've ever seen this morning (both devices,) I wonder has the FAA made any changes to their UAT logic? ...

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I read something in the reddit stream (I think it was) where the FAA had mandated a change to ADS-B that was to take place this month. I don't remember the specifics, but perhaps that's what you're noticing?

 
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9/15/2015 4:35 PM
 
David wrote:

I flew my Stratux Pi (978mhz only) this morning with excellent results on my Samsung Tab S. I had it side by side with my Original SkyRadar on my '720. The SkyRadar was connected to a belly mounted antenna, while the NooElec receiver used the supplied antenna adjusted to 7.75" placed on the panel. Below about 2500' AGL the SkyRadar had a higher data rate, but above that the NooElec Pi combo performed as well or better, with a 0 CRC error rate. SkyRadar averaged around 0.7% CRC errors.

The only interesting observation was that I had a very persistent traffic ghost on the Tab S, but none on the '720. All other traffic showed the same on both setup's. The ghost filter on both devices was on. I wonder is this ghost filter on the Android 9.3.21 working as well as 9.3.21 on the '720? It also seemed like I had the best traffic coverage that I've ever seen this morning (both devices,) I wonder has the FAA made any changes to their UAT logic?

A lot of bang for the buck here, and many thanks to the Stratux developer!!

David

One thing the Stratux is missing vs. other ADSB devices in a GPS receiver. So your Tab S, I presume, was using it's internal GPS. And that may have been off far enough for the ghost detection to not work very well.


Walter Boyd
President, Adventure Pilot
 
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9/17/2015 4:02 AM
 

Dumb question on Ghost Traffic and how ADS-B works.

First flight tonight with ADS-B in. (Stratux.) I am not ADS-B out, nor Mode S. (Old Mode C.)

Immediately after takeoff I got an alert that someone was right next to me, flying my altitude. I assumed that target was me.

So, do I show up on ADS from the FAA? (They pick up my Mode C, run it thru their computers, and spit me out on 978 MHz?)

I turned on the Ghost Filter and my target went away for a while.

Another aircraft took off behind me. I could see his target down low but for some reason I lost him when he was 3000 ft above me, circling back to the south on the Instrument Departure. (Strict warnings, unlimited altitude and distance.)

I was circling over the field at midnight.

Suddenly, I got an alert of someone at my altitude flying the opposite direction. No NAV lights nor did my Monroy ATD-300 passive PCAS pick up anything on 1090. Could that have been me with a lot of lag from the FAA? (Ghost filter was still on.) Or govt spooks flying at night with lights off?

After that target went away, I turned the Ghost filter off. My "ghost" target never came back for the rest of the flight. So I'm confused. Should I be using the Ghost filter as a non-ADS-B out aircraft? Per Walter above, I use a GPS dongle separate from the Stratux.

 
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9/17/2015 4:49 PM
 
ErgoMike wrote:

Dumb question on Ghost Traffic and how ADS-B works.

First flight tonight with ADS-B in. (Stratux.) I am not ADS-B out, nor Mode S. (Old Mode C.).



OK I'm confused. If you are not ADS-B out, (or you're not in the "donut" of a plane that is) how are you receiving traffic (TIS-B)?

I have been using a Dual XGPS170 for about a year now. I'm only used to seeing sporadic traffic. So I still use my PCAS in addition to iFLY. In fact, my main reason for having the XGPS170 is weather, not traffic. I live in thunderstorm country!

Vaughn Simon Nexus 7 with Dual XGPS170
 
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9/17/2015 6:48 PM
 

With only ADS-B in, you only see traffic that is broadcasting with ADS-B out on your specific frequency 978 or 1090. You do not receive traffic being broadcast by the ground stations unless you intercept the signal being broadcast from the ground station to a nearby airplane with ADS-B out which has activated the ground station. This is why ADS-B in is almost useless for traffic if you don't also have ADS-B out.

 
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