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  #1  
Old 06-19-2019, 03:37 PM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
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Default uAvionix echoUAT Weather

I have an echoUAT displaying traffic and weather on a mini iPad3 running ForeFlight. The weather is depicted in very large block pixels. A friend has dual Dynon HDX and his in-flight weather is smooth contours with no pixilation.

I contacted ForeFlight and they tell me that weather from the ADS-B is normally the large pixelated version of radar. The nice high definition radar takes a lot of data to render and the ADS-B system needs efficiency.

See cell phone photo below of my in-flight weather. Is this what everyone’s ADS-B weather looks like?

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Jim Stricker
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  #2  
Old 06-19-2019, 05:31 PM
SPX SPX is online now
 
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The closer that you are to the radar image, the greater definition you should get. In other words, what you showed us here is what I'd expect to see when you're several hundred miles from the location displayed.

How far were you from Pittsburgh when this picture was taken?
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  #3  
Old 06-19-2019, 05:55 PM
BobTurner BobTurner is offline
 
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The radar data is binary: if looking within 250 nm of your position, you should get higher definition. If more than 250 nm, you get the larger pixels.
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  #4  
Old 06-19-2019, 08:55 PM
Paul 5r4 Paul 5r4 is offline
 
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I flew just a couple days ago and was ranging from 5-30 miles from some heavy rain in my area. The entire flight the ifly 740 display fed from uavionix echo UAT looked exactly like yours.
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  #5  
Old 06-19-2019, 09:16 PM
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GalinHdz GalinHdz is offline
 
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Quote:
Originally Posted by BobTurner View Post
The radar data is binary: if looking within 250 nm of your position, you should get higher definition. If more than 250 nm, you get the larger pixels.
EXACTLY. Most people on this forum don't understand the RADAR data being transmitted to them and how it is displayed.
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Last edited by GalinHdz : 06-20-2019 at 08:22 AM.
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  #6  
Old 06-19-2019, 10:06 PM
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All EFIS systems receive the same NEXRAD data streams. Some vendors believe that it should be displayed as is. In this case you will see a pixelated edge. Other vendors will use algorithms to operate on the data stream to smooth the contours.
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  #7  
Old 06-19-2019, 11:59 PM
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Piper J3 Piper J3 is offline
 
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Originally Posted by BobTurner View Post
The radar data is binary: if looking within 250 nm of your position, you should get higher definition. If more than 250 nm, you get the larger pixels.

Quote:
Originally Posted by SPX View Post
The closer that you are to the radar image, the greater definition you should get. In other words, what you showed us here is what I'd expect to see when you're several hundred miles from the location displayed.

How far were you from Pittsburgh when this picture was taken?
About 90 miles away. This image is typically what I see even when receiving multiple ADS-B towers and weather is close.

My guess is ForeFlight chooses to display pixilated radar and Dynon, with their fancy HDX, chooses to smooth and contour the edges - each using same data stream from the ground ADS-B towers.

I wonder if ForeFlight couldn’t massage the data internally in the EFIS (in my case mini iPad3) and display a smoother image? I understand bandwidth and efficiency of ADS-B being sent up from the towers, but once the data is received maybe ForeFlight can pretty it up? Maybe some EFIS don’t have internal capability to manipulate data but an iPad is ideal for doing that. Perhaps FF, if running on an iPad, could do special radar rendering? User might need to stipulate what type of EFIS is being used just like user now chooses 4-color radar, etc.
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Jim Stricker
Hinckley, Ohio (1OA2)
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
RV-12 E-LSA #120058 AWC July 2012 N633CM
RV-12 Bought Flying Oct 2015 with 48TT - Hobbs now 488

LSRM-A Certificate 2016
Special Thanks... EJ Trucks - Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - 1st Lt. Captain B-17H

Last edited by Piper J3 : 06-20-2019 at 01:08 AM.
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  #8  
Old 06-20-2019, 10:28 AM
YellowJacket RV9 YellowJacket RV9 is offline
 
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I think the pixelation is a good reminder of how inaccurate the picture can be. Artificially smoothing it out could give a false sense of detail and encourage somebody to shoot a gap that doesn’t exist.

Another question is, are you sure your buddy’s data is from adsb and not XM? My GRT displays radar the same as FF, for the record.

Chris
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  #9  
Old 06-20-2019, 02:54 PM
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Piper J3 Piper J3 is offline
 
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Quote:
Originally Posted by YellowJacket RV9 View Post
I think the pixelation is a good reminder of how inaccurate the picture can be. Artificially smoothing it out could give a false sense of detail and encourage somebody to shoot a gap that doesn’t exist.

Another question is, are you sure your buddy’s data is from adsb and not XM? My GRT displays radar the same as FF, for the record.

Chris
Good point on the pixelation. Probably some liability concerns on FF's part.

My friend doesn't have XM so the radar image depicted on the HDX is from ground ADS-B. I'll snap photo next time we fly...
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Jim Stricker
Hinckley, Ohio (1OA2)
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
RV-12 E-LSA #120058 AWC July 2012 N633CM
RV-12 Bought Flying Oct 2015 with 48TT - Hobbs now 488

LSRM-A Certificate 2016
Special Thanks... EJ Trucks - Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - 1st Lt. Captain B-17H
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  #10  
Old 07-15-2019, 10:02 AM
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Piper J3 Piper J3 is offline
 
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Default uAvionix echoUAT - Weather Display Problem...

It’s a nice day in northern Ohio today so I took an hour flight. I have uAvionix echoUAT with iPad running ForeFlight. I show targets on the iPad even sitting on the ground because I’m locating in “B” airspace. Once in cruise flight I zoomed out to check for weather and saw none even with tropical storm Barry moving up from the gulf coast. Weather finally showed up about twenty minutes into the flight. FF showed ADS-B as good and ground towers and traffic appeared right away but weather was much delayed to populate the screen. I have seen this in the past so today I paid closer attention and it seems to be as I describe above.

Anybody else see this?
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Jim Stricker
Hinckley, Ohio (1OA2)
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
RV-12 E-LSA #120058 AWC July 2012 N633CM
RV-12 Bought Flying Oct 2015 with 48TT - Hobbs now 488

LSRM-A Certificate 2016
Special Thanks... EJ Trucks - Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - 1st Lt. Captain B-17H
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