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-   -   uAvionix EchoUAT and Disappearing Targets (https://vansairforce.net/community/showthread.php?t=161129)

TimO 08-10-2018 04:11 PM

Wonder why they don't simply make those 2 variable user configurable. I would like to see further than 20 miles when I'm out in the middle of nowhere with no traffic. It should be easy for them to allow you to set user defined limits, and then set a "max intruders" setting that is settable from 10 to 32 or something like that.

dtw_rv6 08-10-2018 04:31 PM

Honestly I couldn't care less about the 4th or 5th farthest target from my position.

I agree that we should be able to set how many returns we want to bother with. If some people like to see the totally obscured moving map like we had at Oshkosh, then more power to them.... hockey pucks don't matter at all when I'm in the pattern with 4 or 5 airplanes.

maniago 08-21-2018 11:41 AM

Anyone have any new TECHNICAL news on this issue?


(Moderators!!!! pls dont lock this thread - its the only tech one we have on the Echo and thats still important for the community......).

Paul 5r4 08-21-2018 12:22 PM

I still see targets disappearing at times. Not nearly as bad as before their software upgrade. It's still frustrating though. I had complete faith in the
EXP Navworx box I had. It performed flawlessly the entire time I used it. You can't help but to aquire a feeling of "faith" in your equipment. I don't have that feeling with the echo UAT. I do hope they'll continue to work on this issue.
I'm not a tech guy at all and can't begin to understand how it works. It seems that programming the software to exclude any targets 20 miles out would decrease the electronic workload. But...... it seems this is some basic internal flaw in either the hardware or software. I mean other companies have software that never drops targets... so you have to conclude there is something or a lack of something in the echo causing this.
Hoping they'll come out with something soon.

Piper J3 08-21-2018 02:36 PM

I emailed Kurt on 8-15-18 at uAvionix to ask if I could participate in Beta testing. His reply below:

We got some feedback from other testers and we are making yet another tweak. It's getting there and I appreciate your willingness to help. I'll shoot you a link when the next version is ready, with instructions for updating.
We will need logging so the engineers can go over them and replay the flight as well.

Paul 5r4 08-21-2018 11:04 PM

Thanks for the update Jim! Nice to know.

rv6n6r 08-23-2018 07:35 PM

Intesting that others with Navworx have reported better filtering. I did the AMOC update on my -600B and get clean bills of health from the ADS-B reports. But I also get disappearing airplanes all the time.

I believe that much of this is just when I drop below or go outside rebroadcast range, so I'm losing direct broadcast from aircraft with 1090MHz transmitters. But it also happens where there should be good radar and rebroadcast coverage. For example, in or near PDX class C, 3000 or above, sometimes ATC will call out an airliner (like, close enough I can see which airline), and I never see it on my screen. Why wouldn't I see all of those guys from the rebroadcast?

Paul 5r4 09-07-2018 12:28 AM

I just saw Randall's post above. I flew the navworx EXP I think about 18 months before having to remove it. I never even once saw a single target disappear weather I was flying in my local area or a cross country. With the Uavionix, I see
targets disappearing, (or not ever showing up), frequently enough that's it's noticeable.
When I lose targets on the echo, I'm flying in the same areas and altitudes I did with navworx which as I mentioned never lost a target.

lr172 09-08-2018 12:58 PM

Quote:

Originally Posted by rv6n6r (Post 1283062)
Intesting that others with Navworx have reported better filtering. I did the AMOC update on my -600B and get clean bills of health from the ADS-B reports. But I also get disappearing airplanes all the time.

I believe that much of this is just when I drop below or go outside rebroadcast range, so I'm losing direct broadcast from aircraft with 1090MHz transmitters. But it also happens where there should be good radar and rebroadcast coverage. For example, in or near PDX class C, 3000 or above, sometimes ATC will call out an airliner (like, close enough I can see which airline), and I never see it on my screen. Why wouldn't I see all of those guys from the rebroadcast?

If your configuratoin tells the ground station that you receive 1090, they won't rebroadcast any 1090 traffic for you. It is assumed you get it air to air. They only rebroadcast traffic on the frequencies that you are not capable of receiving (your unit tells them this based upon your configuration). They broadcast non-adsb traffic (transponder equipped) to everyone.

rv6n6r 09-19-2018 10:16 AM

Quote:

Originally Posted by lr172 (Post 1287005)
If your configuratoin tells the ground station that you receive 1090, they won't rebroadcast any 1090 traffic for you. It is assumed you get it air to air. They only rebroadcast traffic on the frequencies that you are not capable of receiving (your unit tells them this based upon your configuration). They broadcast non-adsb traffic (transponder equipped) to everyone.

Makes sense except as it turns out I don't get 1090 directly on the NAVWORX, only UAT. That was a mistake in my post, sorry! Should have said:
Quote:

I believe that much of this is just when I drop below or go outside rebroadcast range, so I'm losing rebroadcast from aircraft with 1090MHz transmitters

erich weaver 09-19-2018 11:37 AM

Quote:

Originally Posted by TimO (Post 1279937)
Wonder why they don't simply make those 2 variable user configurable. I would like to see further than 20 miles when I'm out in the middle of nowhere with no traffic. It should be easy for them to allow you to set user defined limits, and then set a "max intruders" setting that is settable from 10 to 32 or something like that.

The GRT SX EFIS (and other models Im sure) provides user configurable filtering of traffic based on both lateral distance and altitude difference. It works quite well with the ECHO UAT/GRT SafeFly GPS unit. There is also a "Traffic Alert Window" that will pop up on the map page when traffic is within 2 nm that really gets your attention. You can activate that feature from Set Menu, Moving Map, Traffic Alert Window.

Erich

rvator4twa 09-19-2018 06:19 PM

UAT Echo
 
I have been flying with the UAT Echo for about a week now and I would hate the thought of not having traffic and weather. I have had a few instances of disappearing and reappearing traffic as others have reported. Once I had my wiring complete, Jeff at GRT spent about an hour plus directing the set up which was way beyond my skills but he persisted until it worked on both my Horizon EX and secondary Sport EX. On a recent cross country flight, having the traffic available on her screen, got my wife a whole lot more involved and engaged than ever before, which is a real positive to me. In retrospect, I would trade the upgrade touch screens for a heads up display, as I find the buttons more than sufficient. Today on my BFR flight, my CFI was also pulling up traffic on ForeFlight using his iPad. I heartily recommend the GRT EFIS/UAT ECHO combo if you are sitting on the fence like I was.

Piper J3 10-02-2018 10:48 AM

I emailed Kurt @ uAvionix Support for an update on Disappearing Targets. Here is his response:

We have tested 3 builds so far and are getting closer. Testing continues because we have seen interesting behavior on data handling through some of the EFB and EFIS platforms. The way some of them do coasting is a bit of an issue. We have a build being tested now on a couple EFB's.

Paul 5r4 10-02-2018 11:35 AM

Thanks for the update.

Paul 5r4 10-14-2018 07:25 AM

I flew to Baton Rouge Louisiana Friday then back to my home base of Foley, Alabama Saturday afternoon. I was paying particular attention to traffic and noticed on both trips several targets performing the magic trick of disappearing. I'll be happy when there's a solution from Uavionix. I know they're suppose to be working on it.

Piper J3 10-16-2018 08:09 PM

Flew yesterday with a second plane in near-trail formation. Planes separated by ~ 1 mile. Both planes equipped with ADS-B in/out. My plane has echoUAT + SkyFYX-EXT with WiFi to mini iPad running ForeFlight. The second plane has dual Dynon HDX. We were in constant air-air comm and when I lost targets the second plane reported that I disappeared from his traffic screen. When I regained traffic on my iPad the second plane reported that I returned as traffic on his screen.

Has anyone else seen this?

I?m going to send this info to uAvionix and see what they say.

Piper J3 10-17-2018 01:44 PM

Update...

I emailed uAvionix with above disappearing target information and they got back to me right away. They asked for N# and date of flight. I supplied the flight info and attached the PAPR for the flight in question and they said they are able to get an even more detailed PAPR... maybe because they are a mfg.

So, uAvionix has our attention and is actively working to find a solution...

rocketbob 10-17-2018 05:44 PM

Quote:

Originally Posted by Piper J3 (Post 1295893)
Has anyone else seen this?

Yes I've seen this type of thing happen while flying with friends with different makes and models of ADS-B equipment.

The ADS-B protocols have no provisions for dealing with contention or congestion. Get used to it, there's no fixing this. Not a good design.

TimO 10-17-2018 09:58 PM

The issue has nothing to do with protocols and congestion. It's not something that happens with all systems. Now that I've switched to the Lynx Transponder, nothing disappears ever, and everything works exactly as one would expect it to. This being my 3rd system installed in each of 2 planes, I can say that the disappearing is unique to my 2nd system...the echo.

rocketbob 10-17-2018 10:48 PM

Quote:

Originally Posted by TimO (Post 1296100)
The issue has nothing to do with protocols and congestion.

Thats because they've implemented coasting.

The 978 protocol does not have any sort of mechanism to prevent collisions or request retransmissions if two or more nodes transmit at the same time.

TimO 10-19-2018 03:11 PM

Ah, sorry Rocketbob, with your reply I understand what you are saying. On the Lynx they implement coasting. Yes, I think basically all good systems implement coasting to one degree or another, because you're right, you can receive those broadcasts any time even from 2 people at the same time. Coasting absolutely helps get rid of disappearing. It's one of the things we did in our box to fix all that mess with the Echo. Sadly, it's just one of the many things that aren't done quite right. I'm not sure what qualifies as "the biggest" problem, but certainly one important one is also the lack of sorting, so you may pick up a target 50 miles away but not pick up one that's 1 mile away. But I won't go on and on anymore about it. I pulled mine out, stuck in the L3, and couldn't be happier. If people want to build the filter box, all the info is available, and they help a lot.

rocketbob 10-19-2018 03:22 PM

From what I understand the Packet Error Rate (PER) on 978 is around 33%. So 33% of packets get stepped on, lost, whatever. The ground stations lose these packets and don't rebroadcast them, so they get dropped. Add shadowing, less than ideal antennas, etc. one can see how the system is flawed.

Coasting is the bandaid fix for these flaws.

No other countries have adopted the 978 standards, and this sort of thing tells me why.

Piper J3 10-20-2018 07:00 AM

Quote:

Originally Posted by rocketbob (Post 1296475)
From what I understand the Packet Error Rate (PER) on 978 is around 33%. So 33% of packets get stepped on, lost, whatever. The ground stations lose these packets and don't rebroadcast them, so they get dropped. Add shadowing, less than ideal antennas, etc. one can see how the system is flawed.

Coasting is the bandaid fix for these flaws.

No other countries have adopted the 978 standards, and this sort of thing tells me why.

In layman's terminology... are you saying uAvionix can't fix disappearing targets with software revision? When they say they're working on fix - you think it's technically not possible...

330drvr 10-20-2018 10:32 AM

I don't know the software ins and outs, but the Navworx install had no disappearing targets and it only received the 978 signal. Echo gets both 978 and 1090 traffic directly. I still am hopeful (maybe I am naive) that a software fix from Uavionix Echo is feasible.

rocketbob 10-20-2018 12:29 PM

Quote:

Originally Posted by Piper J3 (Post 1296570)
In layman's terminology... are you saying uAvionix can't fix disappearing targets with software revision? When they say they're working on fix - you think it's technically not possible...

Most systems "fix" the problem by caching the targets for a period of time after the target disappears. Sometimes the target reappears and you don't notice the difference. They likely just need to tweak their software to cache closer targets longer. This is an educated guess.

Also what I am saying is that the ADS-B 978 protocol is poorly designed, so 978 units have to make up for technical deficiencies of the system. This is one of the reasons why no other countries have adopted the same system.

BobTurner 10-20-2018 01:04 PM

Is this problem unique to UAT? e.g., there are more 1090 SES units out there than UATs. Do UATs run at lower speeds?

TimO 10-20-2018 08:00 PM

I don't know the RF side of things with nearly as much detail as the serial side of things, but it seems to me that both 978mhz and 1090mhz would have the same basic transmissions, and it's something like once per second that they send their information. There's less bandwidth in the 1090mhz spectrum overall, but on the 978mhz side, they also send weather/notam information too. So in some respects I can see that taking a bit of that larger bandwidth up. Still, I am doubtful that the simple fact of sticking wx+traffic on the 978mhz side should cause any worse traffic issues than on the 1090mhz side. I think really that most everybody in Avionics does some coasting. And I think that on either side, that helps a lot. I know for sure when I was still running the echos, that adding traffic sorting and then coasting did some drastic improvements to the traffic functionality of the system. If you simply strip out the non-factor traffic, that drastically too would improve the serial data flow. So getting better function out of the system should not be THAT hard. We did it ourselves. What really got me to give up was the constant ghost/shadow targets that I simply could not get rid of. With NavWorx, it was a VERY VERY occasional thing. But that box had a lot stronger transmitter. I think the very much less powerful transmitter in these micro boxes probably adds to the shadow target problem because you have radar stations picking up your transponder from far far away, but the GBT may not "see" your UAT signal at the same time. That makes it much harder for the system to merge these targets. I was getting shadows all the time when flying around MSP airspace, doing flight profiles that were never a problem before. And, even with the new Lynx, are not a problem. I really got tired of hearing "traffic" only to see it located at my own position. I think we got that all figured out too, but after spending hundreds of hours and probably nearly $1000 extra dollars on stuff along the way, I felt it was best just to move on. There are just too many things that really should be improved, and transmitter power is one that I couldn't do anything with.

Piper J3 10-21-2018 02:46 AM

TimO

Would weak echo Tx power explain disappearing target as I explain in my post #56 above?

Piper J3 11-12-2018 12:47 PM

I emailed Kurt at uAvionix again to ask if any progress on echoUAT disappearing targets. Ryan at uAvionix Support replied and sent a software “build” for me to try and report back.

Problem is I fly off of a grass field and this fall it is a total swamp with all the rain in the northeast. I may not fly again until spring.

I asked uAvionix if others could try and evaluate this new software. Ryan asks that each person wanting to try the software to contact him so he can control the release.

Email…. support@uavionix.zohodesk.com
Attn: Ryan

You can find the file update process here: http://uavionix.com/support/update-echouat-software/

Keep me in the loop... :D

Jim

Piper J3 11-23-2018 03:02 PM

I went out to the plane today and installed the new uAvionix software "build" for disappearing targets. Updating the echoUAT is easy even without internet connectivity at the hanger. Thought I might be able to fly - ended up walking the runway and determined its still too wet for ops. Probably now have to wait until runway freezes hard.

revenson 11-23-2018 03:26 PM

Tried the latest firmware build the other day. Went on a 30 minute flight out, then back again after a lunch break. Was in a radar service area the whole flight. Set the ADS-B 'hockey puck' in my GRT EFIS to 15 nm and +/- 3500 feet. Watched carefully the whole flight. The airspace wasn't real busy, but did NOT see any disappearing targets. Happy so far.

gmcjetpilot 11-23-2018 08:30 PM

People are "heads down" focused on their glass, can lose the art of scanning for traffic and situational awareness. ADS-B "IN" is a wonderful thing, but sole over reliance on it for traffic avoidance might not be wise. There's no guarantee all traffic will show up after 2020. There's a lot of non ADS-B airspace below 10,000 feet (or 2,500 feet agl), outside Class B & C, plus no-electrical system aircraft. TCAS in airliners uses a totally separate system from ADS-B, but still relies on at least traffic with Mode C transponders. You still have to look. I have seen traffic that was not on the TCAS, and it was close.

This is a pretty good source of traffic scanning and collision avoidance.

https://www.cfinotebook.net/notebook...sion-avoidance

Piper J3 11-24-2018 04:17 AM

Quote:

Originally Posted by revenson (Post 1304537)
Tried the latest firmware build the other day. Went on a 30 minute flight out, then back again after a lunch break. Was in a radar service area the whole flight. Set the ADS-B 'hockey puck' in my GRT EFIS to 15 nm and +/- 3500 feet. Watched carefully the whole flight. The airspace wasn't real busy, but did NOT see any disappearing targets. Happy so far.

Good news... Please keep us updated with future flights.

Also, uAvionix has asked that you report your observations back to them. Perhaps they will change this software from "build" to a permanent revision.

Piper J3 11-24-2018 04:33 AM

Quote:

Originally Posted by gmcjetpilot (Post 1304598)
People are "heads down" focused on their glass, can lose the art of scanning for traffic and situational awareness.

Your point is well taken, but in my case, I come from flying a J3-Cub for 23 years so I'm pretty astute at scanning for traffic and situational awareness. I use ADS-B to look ahead to start getting "picture" of traffic at destination. In my opinion this helps with situational awareness and improves resource management.

Lars 11-24-2018 10:49 AM

Quote:

Originally Posted by revenson (Post 1304537)
Tried the latest firmware build the other day. Went on a 30 minute flight out, then back again after a lunch break. Was in a radar service area the whole flight. Set the ADS-B 'hockey puck' in my GRT EFIS to 15 nm and +/- 3500 feet. Watched carefully the whole flight. The airspace wasn't real busy, but did NOT see any disappearing targets. Happy so far.

I'm not seeing any newer system software on uAvionix's website than release 3.26, dated 3/13/18. Am I missing something?

revenson 11-24-2018 11:06 AM

The version I tried is still in test mode. It is not on the website.

Piper J3 11-25-2018 03:53 AM

Quote:

Originally Posted by Lars (Post 1304667)
I'm not seeing any newer system software on uAvionix's website than release 3.26, dated 3/13/18. Am I missing something?

See.... http://www.vansairforce.com/communit...4&postcount=69

Paul 5r4 11-25-2018 08:13 AM

So glad to see this latest report. My wing tank is off for repairs. Soon as it's back on, I'm going to get this software installed.

Lars 11-25-2018 10:58 AM

Quote:

Originally Posted by Piper J3 (Post 1304746)

Ah. Thanks. My eyes saw that but somehow my brain didn't respond...

Dan92 12-23-2018 01:27 PM

I got the new test firmware from Ryan and no disappearing traffic so far.

Dan


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