All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 40 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: MLAT Anomalies
PostPosted: Tue Apr 11, 2017 4:14 am 
Offline
FlightAware Member
conligwx - FlightAware user avatar

Joined: Sat Mar 18, 2017 8:00 pm
Posts: 88
Location: EGAC/EGAD
Anyone else getting MLAT Anomalies


Quote:
Anomaly report for PiAware site 40150 - ConligWX:
This feeder is not being used for multilateration because its timing information appears to be unreliable. This can be caused by the site location being incorrect, or because your Pi is running out of free CPU.


can't see anything wrong my end, but have read older post of this issue has cropped up before.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Tue Apr 11, 2017 5:32 am 
Offline
FlightAware Member
conligwx - FlightAware user avatar

Joined: Sat Mar 18, 2017 8:00 pm
Posts: 88
Location: EGAC/EGAD
Looks like its my end. dump1090-fa still running but cannot ssh or use the Send command to device feature here.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Tue Apr 11, 2017 11:08 am 
Offline
FlightAware Staff
david.baker - FlightAware user avatar

Joined: Thu Jan 23, 2014 12:34 pm
Posts: 164
PiAware defaults to SSH off. Instruction to turn on SSH is here:
https://flightaware.com/adsb/piaware/build/optional

Basically you can create a "ssh" file in the SD card's boot directory or run the "sudo raspi-config" program.

MLAT timing is usually due to your site's location not set. Go to your "My ADS-B" page through the link at the top of this webpage.
Go to the location section and check if the value is set correctly.

The other MLAT problems are usually due timing on your PiAware.
Timing problems can be hard to diagnose since it can come from delays in the USB system to delays in the CPU.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Tue Apr 11, 2017 5:47 pm 
Offline
FlightAware Member
conligwx - FlightAware user avatar

Joined: Sat Mar 18, 2017 8:00 pm
Posts: 88
Location: EGAC/EGAD
david.baker wrote:
PiAware defaults to SSH off. Instruction to turn on SSH is here:
https://flightaware.com/adsb/piaware/build/optional

Basically you can create a "ssh" file in the SD card's boot directory or run the "sudo raspi-config" program.

MLAT timing is usually due to your site's location not set. Go to your "My ADS-B" page through the link at the top of this webpage.
Go to the location section and check if the value is set correctly.

The other MLAT problems are usually due timing on your PiAware.
Timing problems can be hard to diagnose since it can come from delays in the USB system to delays in the CPU.


SSH was enabled and Location was set it - it was all working fine until today. The only thing I can think was, that I had running on PiAware that was extra was FlightRadar24, Planefinder and I added yesterday Opensky.

maybe I had overloaded the pi? I dunno, I have uninstalled Planefinder and Opensky for now. I will monitor the situation.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu Apr 20, 2017 11:51 am 
Offline
BE35G - FlightAware user avatar

Joined: Sun Feb 05, 2006 9:00 am
Posts: 16
Just wondering, from about 0800 to 1700 local time my mlat count goes down, sometimes to zero. I have looked to other systems near my location and they seem to have the same issue. I have looked at some sites near me in rankings in other parts of the country, i.e. NY, and they do not seem to have this issue.

Do I have an issue, or is this a "DFW" server issue?

[2017-04-20 11:34 CDT] mlat-client(2515): Receiver status: connected
[2017-04-20 11:34 CDT] mlat-client(2515): Server status: synchronized with 90 nearby receivers
[2017-04-20 11:34 CDT] mlat-client(2515): Receiver: 1314.6 msg/s received 434.9 msg/s processed (33%)
[2017-04-20 11:34 CDT] mlat-client(2515): Server: 0.0 kB/s from server 0.0kB/s TCP to server 5.0kB/s UDP to server
[2017-04-20 11:34 CDT] mlat-client(2515): Results: 5.2 positions/minute
[2017-04-20 11:34 CDT] mlat-client(2515): Aircraft: 96 of 172 Mode S, 28 of 88 ADS-B used

http://flightaware.com/adsb/stats/user/ ... tats-19502

Thanks,

Larry


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu Apr 20, 2017 3:59 pm 
Offline
FlightAware Member
fatherdoctor - FlightAware user avatar

Joined: Thu Aug 06, 2015 3:53 pm
Posts: 50
BE35G wrote:
Just wondering, from about 0800 to 1700 local time my mlat count goes down, sometimes to zero. I have looked to other systems near my location and they seem to have the same issue. I have looked at some sites near me in rankings in other parts of the country, i.e. NY, and they do not seem to have this issue.

Do I have an issue, or is this a "DFW" server issue?


Practically neighbors... Been having the problem for a long while now. That bottom line shows the issue. For some reason the server is rejecting over half of the Mode-S positions, and less than one quarter of the ADS-B positions.

[2017-04-20 15:51 CDT] mlat-client(24786): Receiver status: connected
[2017-04-20 15:51 CDT] mlat-client(24786): Server status: synchronized with 93 nearby receivers
[2017-04-20 15:51 CDT] mlat-client(24786): Receiver: 1115.9 msg/s received 418.8 msg/s processed (38%)
[2017-04-20 15:51 CDT] mlat-client(24786): Server: 0.1 kB/s from server 0.0kB/s TCP to server 4.4kB/s UDP to server
[2017-04-20 15:51 CDT] mlat-client(24786): Results: 59.9 positions/minute
[2017-04-20 15:51 CDT] mlat-client(24786): Aircraft: 81 of 164 Mode S, 23 of 107 ADS-B used


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu Apr 20, 2017 4:15 pm 
Offline
BE35G - FlightAware user avatar

Joined: Sun Feb 05, 2006 9:00 am
Posts: 16
Hey neighbor, wonder if this is system wide or just our neck of the woods. As I was putting together my system, I used your site as a bench mark to try to emulate. I'm down in a low area at the house, but I do the best I can.

Thanks,
Larry


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu Apr 20, 2017 5:23 pm 
Offline
FlightAware Staff
obj - FlightAware user avatar

Joined: Tue Sep 30, 2014 7:14 pm
Posts: 3463
fatherdoctor wrote:
For some reason the server is rejecting over half of the Mode-S positions, and less than one quarter of the ADS-B positions.

That is normal, expected behaviour; the server doesn't ask you for all traffic, only the traffic that's actually needed.

The dropouts are probably server load relaed.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu Apr 20, 2017 5:27 pm 
Offline
FlightAware Member
Skibox - FlightAware user avatar

Joined: Tue Nov 17, 2015 12:33 pm
Posts: 84
fatherdoctor wrote:
For some reason the server is rejecting over half of the Mode-S positions, and less than one quarter of the ADS-B positions.

[2017-04-20 15:51 CDT] mlat-client(24786): Aircraft: 81 of 164 Mode S, 23 of 107 ADS-B used



That is not what the message means.

/M


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu Apr 20, 2017 8:54 pm 
Offline
FlightAware Member
fatherdoctor - FlightAware user avatar

Joined: Thu Aug 06, 2015 3:53 pm
Posts: 50
BE35G wrote:
Hey neighbor, wonder if this is system wide or just our neck of the woods. As I was putting together my system, I used your site as a bench mark to try to emulate. I'm down in a low area at the house, but I do the best I can.

Thanks,
Larry


Haha, I did the same thing with the biggest site in the area when I got going. It was a proud day when I doubled him. ewhalvorsen must have some voodoo magic (or no trees and a 2 story house), because I can't tweak enough to beat him on any given day.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu Apr 20, 2017 9:35 pm 
Offline
FlightAware Member
fatherdoctor - FlightAware user avatar

Joined: Thu Aug 06, 2015 3:53 pm
Posts: 50
Skibox wrote:
fatherdoctor wrote:
For some reason the server is rejecting over half of the Mode-S positions, and less than one quarter of the ADS-B positions.

[2017-04-20 15:51 CDT] mlat-client(24786): Aircraft: 81 of 164 Mode S, 23 of 107 ADS-B used



That is not what the message means.

/M


It was an uneducated WAG. Consider me informed.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Fri Apr 21, 2017 4:21 pm 
Offline
mkeflyer - FlightAware user avatar

Joined: Fri Feb 10, 2006 3:00 pm
Posts: 16
BE35G wrote:
Just wondering, from about 0800 to 1700 local time my mlat count goes down, sometimes to zero. I have looked to other systems near my location and they seem to have the same issue. I have looked at some sites near me in rankings in other parts of the country, i.e. NY, and they do not seem to have this issue.

Do I have an issue, or is this a "DFW" server issue?

[2017-04-20 11:34 CDT] mlat-client(2515): Receiver status: connected
[2017-04-20 11:34 CDT] mlat-client(2515): Server status: synchronized with 90 nearby receivers
[2017-04-20 11:34 CDT] mlat-client(2515): Receiver: 1314.6 msg/s received 434.9 msg/s processed (33%)
[2017-04-20 11:34 CDT] mlat-client(2515): Server: 0.0 kB/s from server 0.0kB/s TCP to server 5.0kB/s UDP to server
[2017-04-20 11:34 CDT] mlat-client(2515): Results: 5.2 positions/minute
[2017-04-20 11:34 CDT] mlat-client(2515): Aircraft: 96 of 172 Mode S, 28 of 88 ADS-B used

http://flightaware.com/adsb/stats/user/ ... tats-19502

Thanks,

Larry


I too have been having the MLAT reception fall to very very low numbers around 6pm CST everyday for the last few days.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Sun Apr 30, 2017 1:11 pm 
Offline
sebgray - FlightAware user avatar

Joined: Mon Mar 09, 2015 3:51 am
Posts: 5
Hi, I started to get a similar issue on my Pi 2 based setup and found that after updating the Pi firmware to 4.9.x kernels I got the dreaded "This feeder is not being used for multilateration because its timing information appears to be unreliable" message on my My ADS-B page

I downgraded the firmware of the pi using this command --->

sudo rpi-update 52241088c1da59a359110d39c1875cda56496764

Which is to kernel version 4.4.50-v7+ (the last one before 4.9.x) after which everything appears to be working as advertised again...

Hope this is of use! :D


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Sun Apr 30, 2017 2:35 pm 
Offline
FlightAware Member
conligwx - FlightAware user avatar

Joined: Sat Mar 18, 2017 8:00 pm
Posts: 88
Location: EGAC/EGAD
Were you using the full piaware image or Debian Jessie lite and dump1090/mutability?

I am running one of my Pi 3's with Kernel 4.9 (ADS-B Receiver Project Setup Scripts image) and dont have this issue.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Sun Apr 30, 2017 3:01 pm 
Offline
sebgray - FlightAware user avatar

Joined: Mon Mar 09, 2015 3:51 am
Posts: 5
I'm running Rasbian Jessie with dump1090-mutability v1.15-dev so its not the FA Piaware image. I'm inclined to think its a Pi2 thing but there you go! I've got 3 other feeder running on the same Pi2. An old PC is running Virtual Radar Server (Linux/Mono) with the FA MLAT helper outputting to it over my LAN. It's a system that's normally very reliable however the Pi kernel 4.9.x upgrade definitely broke the MLAT side of things. YMMV 'natch but worth posting I felt! :)


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Sun Apr 30, 2017 4:53 pm 
Offline
FlightAware Member
conligwx - FlightAware user avatar

Joined: Sat Mar 18, 2017 8:00 pm
Posts: 88
Location: EGAC/EGAD
cheers for the info, will keep an eye on it for now, hopefully I wont need to downgrade, though if I do I may just move to the piaware image since I dont really need all the bells and whistles of mutability


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Sun Apr 30, 2017 7:41 pm 
Offline
vstuart - FlightAware user avatar

Joined: Wed Jun 23, 2010 3:00 pm
Posts: 9
I am also getting this "clock unstable" issue after the running apt-get update/upgrade a few days ago on my Pi 2. Firmware was updated to 4.9.24-v7+. I am running Raspbian Jessie, dump1090-mutability 1.15~dev and the PiAware 3.5.0 package.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Mon May 01, 2017 1:49 am 
Offline
sebgray - FlightAware user avatar

Joined: Mon Mar 09, 2015 3:51 am
Posts: 5
vstuart wrote:
I am also getting this "clock unstable" issue after the running apt-get update/upgrade a few days ago on my Pi 2. Firmware was updated to 4.9.24-v7+. I am running Raspbian Jessie, dump1090-mutability 1.15~dev and the PiAware 3.5.0 package.


This looks like a good opportunity to test this kernel issue! Have you reverted to the older kernel version as per my earlier post? It'll be interesting to see if it resolves the problem... :wink:


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Mon May 01, 2017 2:48 am 
Offline
FlightAware Member
f1jek - FlightAware user avatar

Joined: Mon Sep 30, 2013 2:11 am
Posts: 131
Try removing --forward-mlat from your configuration. :wink:

See post206504.html#p206504

J-Luc F1JEK


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Mon May 01, 2017 6:35 am 
Offline
vstuart - FlightAware user avatar

Joined: Wed Jun 23, 2010 3:00 pm
Posts: 9
f1jek wrote:
Try removing --forward-mlat from your configuration. :wink:

See post206504.html#p206504

J-Luc F1JEK

That's an unrelated issue.

I'll try reverting to kernel 4.4.50 and see if that fixes things.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Mon May 01, 2017 2:05 pm 
Offline
FlightAware Member
f1jek - FlightAware user avatar

Joined: Mon Sep 30, 2013 2:11 am
Posts: 131
K, Excuse me, I saw a time-related and M-LAT issue, but obviously it was not the same.

Hope you will find it.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Wed May 03, 2017 9:06 am 
Offline
bramjacobse - FlightAware user avatar

Joined: Wed Jan 21, 2015 12:27 pm
Posts: 8
I have reverted back to

sudo rpi-update 52241088c1da59a359110d39c1875cda56496764

uname -a
Linux adsb 4.4.50-v7+ #970 SMP Mon Feb 20 19:18:29 GMT 2017 armv7l GNU/Linux

It fixes my Mlat problems... 8)


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Wed May 03, 2017 2:32 pm 
Offline
sebgray - FlightAware user avatar

Joined: Mon Mar 09, 2015 3:51 am
Posts: 5
bramjacobse wrote:
I have reverted back to

sudo rpi-update 52241088c1da59a359110d39c1875cda56496764

uname -a
Linux adsb 4.4.50-v7+ #970 SMP Mon Feb 20 19:18:29 GMT 2017 armv7l GNU/Linux

It fixes my Mlat problems... 8)


Great news! Are you running a Pi 2 as well or a Pi 3? Like I posted earlier I'm sure this is a Pi 2 problem... :)


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu May 04, 2017 7:56 am 
Offline
vstuart - FlightAware user avatar

Joined: Wed Jun 23, 2010 3:00 pm
Posts: 9
Downgrading my Pi 2 kernel to 4.4.50 does appear to have resolved this issue - thanks for the suggestion sebgray. I wonder what the root cause is.


Top
 Profile  
 
 Post subject: Re: MLAT Anomalies
PostPosted: Thu May 04, 2017 8:38 am 
Offline
bramjacobse - FlightAware user avatar

Joined: Wed Jan 21, 2015 12:27 pm
Posts: 8
sebgray wrote:
bramjacobse wrote:
I have reverted back to

sudo rpi-update 52241088c1da59a359110d39c1875cda56496764

uname -a
Linux adsb 4.4.50-v7+ #970 SMP Mon Feb 20 19:18:29 GMT 2017 armv7l GNU/Linux

It fixes my Mlat problems... 8)


Great news! Are you running a Pi 2 as well or a Pi 3? Like I posted earlier I'm sure this is a Pi 2 problem... :)



Pi 2 Model B v1.1 "Revision a01041"


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 40 posts ]  Go to page 1, 2  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: k6rtm and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: