MLAT Unreliable Timing

Very interesting, @SweetPea11. That’s the same message I see when my MLAT flag goes red. I would agree that all these different versions and systems doing it does seem to point to FlightAware for whatever is going on. Also makes me wonder if it’s more widespread but being intermittent, maybe nobody else has spotted it?

This is actually a display bug on the stats page.

2 Likes

Thanks

Good to know.

S.

1 Like

When you have a moment, could you elaborate?

Does one site have a MLAT problem and the stats page is wrongly displaying the message for two sites on that account, or is the stats page wrongly displaying MLAT problems?

Yes, exactly. (20 chars)

MLAT flag went red again and a reboot fixed it again.

@obj - are others having this same MLAT issue or is it just SweetPea11 and myself? Since you guys have the web server that reports it, are there logs that might show if this is just a few of us seeing this issue?

Might just do a full, fresh reinstall of the SD image and see if that helps, but after SweetPea11 reported seeing it too, I wonder if this is more widespread.

No it sounds like one of your sites has a legitimate MLAT issue.
But with this bug it seems hard to say which one.

Well actually you already know:

Mar 19 11:47:23 raspberrypi piaware[544]: mlat-client(24104): Server status: clock unstable

So it’s the one with this in the log.
Do you have another SDR you can try … it’s almost always something along those lines.

I don’t see any unusual behaviour out of the mlat system at the moment if that’s what you’re asking.
It is common for there to be a lot of sites with sync problems (bad locaitons, marginal hardware)

FWIW your receiver looks fine currently (and has been for the last 7000-ish seconds or so):

 PeerID Distance State    Frequency Error    LastReset Expires
 101..2  482.9km Valid      +0.7ppm   1066ns     59.5s -      
 101..6  389.5km New        -0.5ppm     90ns     20.0s   13.2s
 102..9  186.3km Valid      -0.4ppm    114ns   6836.7s -      
 102..8   79.2km Valid      +0.4ppm    249ns   2536.2s -      
 102..5  464.0km Valid      -0.0ppm    399ns     22.9s   23.2s
 102..5  492.7km Valid      +0.9ppm    171ns   4663.6s -      
 102..0   40.7km Valid      +3.0ppm    128ns   6837.5s -      
 102..2   67.3km Valid      -2.0ppm    237ns    156.0s -      
 102..5  226.1km Valid      -0.6ppm    182ns   6838.2s -      
 102..8  112.7km Valid      -0.1ppm    121ns   5650.7s -      
 102..1  462.0km Valid      +0.9ppm    161ns   6836.5s -      
 102..6  454.1km Valid      +0.0ppm    144ns   6836.5s -      
 102..1  326.8km Stepped    +1.2ppm   7072ns      0.0s -      
 102..4  467.5km Valid      +1.2ppm    172ns    638.9s -      
 102..5   66.5km Valid      -2.0ppm     94ns   6838.0s -      
 102..6   71.4km Valid      +0.0ppm    246ns   2089.3s -      
 102..8  458.5km Valid      +0.3ppm    198ns    218.5s -      
 102..2  487.0km Valid      +0.1ppm    153ns   4777.8s -      
 102..9  485.2km Stepped    -0.2ppm   1945ns     14.9s   23.2s
 102..2  459.8km New        -1.0ppm      0ns      0.0s   23.2s
 102..9  404.3km Valid      +0.0ppm    458ns     38.6s -      
 102..0  492.6km Valid      +0.2ppm    184ns   4384.0s   23.2s
 102..7  384.0km New       +49.7ppm      0ns      0.0s    3.2s
 102..1  435.0km Valid      -0.4ppm    139ns   4659.6s -      
 102..8  295.3km Stepped    -0.2ppm   5002ns      3.4s -      
 103..7  459.1km Valid      -3.1ppm    225ns   3202.7s   13.2s
 103..0  384.0km Valid      -0.6ppm    168ns   4667.6s -      
 103..2    5.0km Valid      -0.2ppm    102ns   6834.4s -      
 103..3  249.4km Valid      -0.1ppm    101ns    419.5s -      
 103..4  443.1km Valid      -0.6ppm     94ns    594.2s -      
 103..6  247.5km Valid      +1.6ppm    570ns     62.6s -      
 103..9  450.6km Valid      -0.0ppm    313ns    107.4s -      
 103..3   73.7km Valid     +80.4ppm    144ns   6838.6s -      
 103..1   42.1km Valid      -0.6ppm    575ns   5546.9s -      
 103..5  385.0km New        -0.4ppm    130ns      2.9s -      
 103..4  369.9km Valid      +1.2ppm    122ns     65.3s -      
 103..4  394.2km Valid      +0.0ppm    154ns   6837.1s -      
 103..4  462.9km Valid      -1.5ppm    102ns    540.9s -      
 103..9  344.4km Valid      +0.6ppm     97ns   6837.7s -      
 103..9   79.7km Valid      -0.7ppm    105ns   6836.9s -      
 103..5  453.7km Valid      -0.7ppm   1896ns     45.4s -      
 103..9   11.4km Valid      +0.1ppm    148ns   6832.8s -      
 103..3  205.4km Valid      +1.0ppm    138ns   6837.1s -      
 103..8  407.9km Valid      +0.1ppm    109ns   6837.0s -      
 103..3  387.8km Valid      +1.1ppm     99ns    398.6s   13.2s
 103..4   71.6km Valid      -0.4ppm    124ns   6838.2s -      
 103..6   10.0km Valid      +0.0ppm     78ns   6838.2s -      
 103..5  380.1km New       +32.4ppm      0ns      0.0s -      
 103..0  154.1km Valid      -0.2ppm    132ns   6837.4s -      
 103..6  227.2km Valid      -0.9ppm    127ns   6837.5s -      
 103..0  379.7km Valid      -0.6ppm   1214ns     42.0s -      
 103..7  463.4km Valid      +3.4ppm    181ns   1400.6s -      
 103..8  528.9km Valid      -0.4ppm    188ns    705.6s   23.2s
 103..4  477.3km Valid      -0.2ppm    176ns   4664.8s -      
 103..3  452.4km New        -0.4ppm    177ns      7.1s -      
 103..3  311.1km New        -0.5ppm    116ns      0.6s -      
 103..6   69.8km Valid      -0.6ppm    108ns   6838.2s -      
 103..3  449.8km Valid      +0.1ppm    129ns   6836.1s -      
 103..0  389.2km Valid      -0.6ppm    137ns   4664.6s -      
 103..7  308.3km Valid      -1.0ppm    126ns     60.3s -      
 103..4  386.3km Valid     +41.6ppm    197ns   4664.8s -      
 103..4   11.0km Valid      -1.4ppm     81ns   6837.9s -      
 103..2  390.5km New        -0.5ppm    647ns     43.1s -      
 103..1   70.5km Valid      -0.4ppm    132ns   6837.8s -      
 103..4  457.0km Valid      +0.1ppm    146ns   6836.5s -      
 103..1  307.3km New        +0.8ppm   2159ns     26.4s   13.2s
 103..3  503.1km New        +0.7ppm    480ns      7.1s -      
 103..1   72.9km Valid     +33.5ppm    126ns   6838.2s -      
 103..8  210.5km Valid      +1.5ppm    105ns   6838.0s -      
 103..8  471.9km Valid      -0.0ppm    142ns   4745.0s -      
 103..2  442.0km Valid      -0.9ppm    242ns    184.1s -      
 103..8  462.1km New        -1.1ppm     32ns      7.1s -      
 103..3  244.1km Valid      -0.1ppm     79ns   6837.8s -      
 103..2  300.9km Valid      -0.1ppm    120ns   1312.4s -      
 103..1  448.7km New        -0.5ppm    139ns      1.1s -      
 103..9  446.1km New        -1.1ppm      0ns      0.0s -      
 103..5   40.0km Valid      -0.1ppm    144ns   6833.0s -      
 103..3  438.7km Valid      -0.5ppm    845ns     27.9s -      
 103..4    8.9km Valid      +0.0ppm     87ns   6837.9s -      
 103..9  442.7km Valid     +76.9ppm     91ns    578.6s -      
 103..9  233.5km Valid      +1.9ppm    666ns   6837.9s -      
 103..4  450.4km Valid      -0.3ppm    141ns   6834.5s -      
 103..8  242.2km Valid      -0.4ppm    113ns   6837.8s -      
 103..0  201.6km Valid      -1.8ppm    106ns   6838.2s -      
 103..4  449.3km Valid      +0.2ppm    105ns   1311.5s -      
 103..2  103.8km Valid      +0.6ppm     86ns   6838.2s -      
 103..6  362.7km Valid      -0.2ppm    313ns     78.4s   23.2s
 103..7  366.1km Valid      +0.0ppm    150ns    740.0s    3.2s
 103..3  285.1km Valid      -2.4ppm    147ns   6838.1s -      
 103..8  326.3km New        -0.0ppm    180ns     44.1s -      
 103..7  497.1km Valid      -0.2ppm    185ns   4756.5s -      
 103..0  329.4km Valid      -0.3ppm     89ns   6837.2s -      
 103..4  317.1km Valid      -1.0ppm    150ns   6837.9s -      
 103..4   74.3km Valid      -1.2ppm    143ns   6837.9s -      
 103..3  487.2km Valid      -0.6ppm    191ns    545.7s   23.2s
 103..4  456.7km Valid      +0.5ppm    118ns    159.2s -      
 103..1  396.0km Valid      -1.1ppm    123ns   4667.8s -      
 103..6  387.3km Valid      +1.1ppm    235ns     30.7s -      
 103..5  420.2km New        -0.2ppm    303ns     20.8s   23.2s
 103..4  386.1km New        -2.8ppm     14ns      1.0s -      
 103..0  368.9km Valid      +0.2ppm    104ns   6837.5s -      
 103..6   74.5km Valid     +70.0ppm   1530ns     57.8s -      
 103..7  241.8km Valid      -0.2ppm    129ns   6837.8s -      
 103..1  230.0km Valid      +0.3ppm    136ns   6838.1s -      
 103..5  509.6km New        +0.0ppm   1289ns     32.8s   13.2s
 103..6  459.3km Valid      -0.8ppm    132ns     71.8s   23.2s
 103..0  202.1km Valid      -0.2ppm    117ns   6837.4s -      
 103..4  208.5km Valid      +0.1ppm    114ns   6837.5s -      
 103..2  511.6km Valid      -0.4ppm    258ns    566.6s -      
 103..9  282.9km Valid      -0.4ppm    122ns   6838.2s -      
 103..1    5.7km Valid      -0.1ppm     83ns   6148.1s -      
 103..0  384.8km Valid      +0.2ppm    167ns   4189.3s -      
 103..7  434.9km Valid      -1.6ppm    122ns   3105.5s -      
 103..0  112.3km Valid      +0.1ppm    495ns   2819.5s -      
 103..9  388.9km New        +0.2ppm      0ns      0.0s   13.2s
 103..1  375.4km Valid      +0.1ppm    116ns   1370.6s   23.2s
 103..0  475.5km New        -0.5ppm      0ns      0.0s    3.2s
 103..2  391.1km Valid      +0.4ppm    154ns    254.7s -      
Pairings: 118  Usable: 96  Unstable: 3
Inhibit: NONE  Instability: 0

 PeerID Distance State    Frequency Error    LastReset Expires
 263206  196.6km Valid      -1.2ppm    126ns   6912.5s -      
 267870  473.4km Valid      -0.7ppm    181ns    845.4s -      
 269267  186.3km Valid      -0.4ppm    162ns   6914.0s -      
 269611   79.2km Valid      +0.4ppm    267ns   2742.8s -      
 269623   74.1km Outliers  +97.6ppm   1033ns    148.0s -      
 269852  114.2km Valid      +0.5ppm    599ns   6914.3s -      
 269888  204.7km Valid      +2.1ppm    133ns   6914.3s -      
 270326   70.1km Valid      -0.2ppm    129ns   6913.8s -      
 270340   75.3km Valid      -0.9ppm    115ns   6914.3s -      
 270430  434.0km Valid      -0.4ppm    159ns    104.8s -      
 270541   40.7km Valid      +3.1ppm    186ns   6913.4s -      
 270572   67.3km Valid      -2.0ppm    224ns    234.2s -      
 270865  112.7km Valid      -0.1ppm    161ns   5726.9s -      
 271280   70.1km Valid      -0.6ppm    203ns   3176.9s -      
 271386   66.5km Valid      -2.0ppm    124ns   6914.6s -      
 271389   68.7km Valid      -1.4ppm     98ns   6914.6s -      
 271392   71.4km Valid      +0.0ppm    329ns   2161.6s -      
 271492   54.9km Valid      +0.2ppm    101ns   6914.3s -      
 271538  418.2km Valid      -1.3ppm    777ns     78.9s   12.8s
 271539  418.2km Valid     +72.8ppm    136ns   2263.0s -      
 271693   77.6km Valid      +0.7ppm    702ns   2403.4s -      
 271749    5.0km Valid      -0.2ppm    141ns   6913.6s -      
 271760  389.0km New        -2.0ppm      0ns      0.0s   22.8s
 271765   64.6km Valid      -0.4ppm    103ns   6914.6s -      
 271779   69.8km Valid      +0.6ppm    148ns   6913.9s -      
 271821   73.7km Valid     +80.3ppm    143ns   6914.3s -      
 271822   81.7km Valid      +0.6ppm    680ns   5745.9s -      
 271837   68.1km Valid      +0.8ppm    162ns   6912.4s -      
 271851   42.1km Valid      -0.7ppm    506ns   5622.9s -      
 271925   72.1km Valid      -0.0ppm    205ns    376.1s -      
 271938   67.7km Valid      -2.3ppm    152ns   6914.6s -      
 271978  393.0km Valid      +0.5ppm    134ns    849.8s -      
 272096   79.7km Valid      -0.7ppm    108ns   6913.7s -      
 272098   11.4km Valid      +0.0ppm    118ns   6908.9s -      
 272103   75.6km Valid      +0.3ppm     96ns   6914.0s -      
 272110  383.0km Valid      +1.1ppm    411ns    310.8s -      
 272112  192.3km Valid      +3.0ppm    399ns     41.1s   22.8s
 272125   71.6km Valid      -0.3ppm    116ns   6914.6s -      
 272126   10.0km Valid      +0.1ppm    106ns   6914.6s -      
 272171  154.1km Valid      -0.2ppm    166ns   6913.4s -      
 272227   76.8km Valid      +0.3ppm    145ns   6914.5s -      
 272252   64.0km Valid      +1.3ppm    252ns   6914.3s -      
 272309  362.5km Valid      +0.9ppm    134ns   6157.2s -      
 272323   69.8km Valid      -0.6ppm    127ns   6914.6s -      
 272351   79.2km Valid      -0.4ppm   1400ns   6914.1s -      
 272358   11.0km Valid      -1.3ppm    126ns   6914.6s -      
 272380   70.5km Valid      -0.4ppm    141ns   6914.4s -      
 272390  107.4km Valid      +5.9ppm    143ns   6913.8s -      
 272399  375.1km Valid      +0.1ppm    226ns   2802.0s -      
 272406   72.9km Valid     +33.6ppm    133ns   6914.4s -      
 272415   81.8km Valid      -0.4ppm    469ns   5726.8s -      
 272465  443.6km New       +45.8ppm     51ns      1.0s -      
 272478   76.5km Valid      +2.2ppm    173ns   6906.4s -      
 272489  111.9km Valid      +0.3ppm    122ns   6914.3s -      
 272495  234.8km Valid      +1.5ppm     87ns   6812.3s -      
 272503  425.9km Valid      +1.2ppm    129ns    889.0s -      
 272505   70.4km Valid      +0.7ppm    134ns   6914.5s -      
 272506   40.0km Valid      -0.2ppm    110ns   6913.4s -      
 272516    8.9km Valid      -0.0ppm     82ns   6914.3s -      
 272529  373.7km Valid     -26.0ppm    151ns    646.8s -      
 272541  103.8km Valid      +0.6ppm     98ns   6914.6s -      
 272543   66.4km Valid      -0.6ppm    109ns   6914.6s -      
 272548  336.4km Valid      -0.1ppm    149ns   6914.0s -      
 272564  525.1km Valid      -0.3ppm   1259ns    119.5s -      
 272579  275.8km Valid      -0.4ppm    128ns   6914.0s -      
 272583  188.7km Valid      +1.1ppm    114ns   6914.4s -      
 272596  413.0km Valid      -0.6ppm     86ns   2432.5s -      
 272603  461.7km Valid      -0.8ppm    119ns    855.9s -      
 272608   74.3km Valid      -1.2ppm    114ns   6914.5s -      
 272639   70.1km Valid      -0.0ppm    112ns   6914.0s -      
 272688   72.1km Valid      -0.9ppm    123ns   6914.2s -      
 272728   17.6km Valid      -0.3ppm     88ns   6914.6s -      
 272735   66.4km Valid      -0.5ppm    227ns   3179.7s -      
 272739   67.8km Valid      +0.7ppm    117ns   6914.1s -      
 272750  544.6km Valid      +1.4ppm    149ns    137.9s -      
 272753   81.8km Valid      -1.1ppm    115ns   6914.4s -      
 272760  287.6km Valid      -0.5ppm    138ns   6914.0s -      
 272767   60.4km Valid      -0.4ppm    104ns   6914.3s -      
 272788  377.7km Valid      -3.4ppm    219ns   1720.3s -      
 272799    5.7km Valid      -0.1ppm    105ns   6224.1s -      
 272803   71.9km Valid      -0.2ppm    128ns   5953.6s -      
 272815  112.3km Valid      +0.1ppm    551ns   2895.7s -      
 272826   61.5km Valid      -0.5ppm    158ns     40.2s -      
Pairings: 83  Usable: 80  Unstable: 0
Inhibit: NONE  Instability: 0

Ok, will start swapping hardware then. When Sweetpea11 said his sites were seeing it too, across different hardware and software versions, even if it was only one of the stations, it seemed that there might be an external cause. Intermittent problems are the worst.

Thanks guys!

As MLAT is not enabled on this site I am unclear how it can have

S.

Did you read the thing about the anomalies being duplicated (display bug?) You should read the thing about the anomalies being duplicated.

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