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New MLAT Regions in Europe?

Discussion in 'Feeding' started by EDMG-1, Nov 13, 2018.

  1. EDMG-1

    EDMG-1 New Member

    Looks like we have a new arrangement for the MLAT regions (4 and 5) in Europe.
    Cutting Germany into 2 pieces, will result in losing most of the low flying MLAT traffic in Germany.
    Sad news :(
     
  2. MDA

    MDA Administrator Staff Member

    Germany is in one piece. New region boundary is Polish border (now we bolong to Asia :D).
    Probably now James is playing with boundaries to test server load.
    MFG
    Marcin
     
  3. MDA

    MDA Administrator Staff Member

    I've seen it. James is configuring new server so I hope it is temporary only.
     
  4. EDMG-1

    EDMG-1 New Member

  5. James

    James Administrator Staff Member

    You won't lose most of low flying aircraft in Germany. In fact, it should improve the MLAT by splitting up the load between server instances. Feeders only MLAT aircraft they have in range anyway.
     
  6. EDMG-1

    EDMG-1 New Member

    Yes, you are right. At least if there is anyone else in your area which is able to join the MLAT calculation.

    At the moment below 10.000ft I can only look to the east now. Mostly, because I can not communicate with the other feeders which are 20 or 50 km to the west. FA MLAT results have overtaken Adsbex for the first time since 2015. :eek: And I am pretty sure that's the same situation for anyone which is located along that border.

    Are you calculating MLAT between the regions as well? I know it is difficult to define the borders. It is always a compromise.

    Regards
    Stefan
     
  7. MDA

    MDA Administrator Staff Member

    James, did you look into region 6? There are some feeders which now doesn't belong to any region (probebly between 1 and 2 degrees East).
     
  8. James

    James Administrator Staff Member

    So the issue is not only does the MLAT server have a limit to the connected clients, but it has a limit to the number of messages it can process.

    Moving the borders around will help, you are only going to get MLAT data for aircraft your feeder can see. So at low altitude it shouldn't matter a great deal if you are on a border.

    FlightAware groups feeders into clusters locally, in a round robin, so they aren't actually processing all feeders and all data. Since FA employs Oliver the developer of the original MLAT server, client , and the dump1090 mutability fork - they have got him to stop development on the software that isn't FlightAware.

    FlightAware wants to shut everyone down, they believe they own ADS-B data around the globe and all the rights to sell it.

    It is what it is, if anyone wants to fork and pick up improving where he left off - code is on github.

    Until that time, or until ADSBx can afford to pay a developer with the skills to develop better MLAT. We do what we can and try to get around FlightAware road blocks.
     
  9. James

    James Administrator Staff Member

    This issue has to do with how the MLAT client connects. We look that connection string, but it doesn't send the string in the same order. We look for 'lon' and route accordingly - sometimes it doesn't send it and feeders end in MLAT 6 as the 'catch all'. Some feeders like ED, who get consistently put in there, you can probably put that issue on the feeder and having an Internet connection that might be losing packets, etc. So we never get the 'lon' and it just gets put in 6.

    My idea to improve is to have new feeder images check the configured feeder lat/lon .. then use the appropriate port when connecting to MLAT for thier region.

    For guys like Ed that have problems, we can login and change the MLAT client port to point to the port for his zone. But getting some people to put ZT on it so I can edit and monitor is an issue - for others it is not.

    Makes sense?
     
  10. MDA

    MDA Administrator Staff Member

    In this case I think there is a gap between region boundaries. Freqman is feeding for a long time without any issues and now landed in region 6.
     
  11. MDA

    MDA Administrator Staff Member

    All of them are on map so positions were received.
    upload_2018-11-14_17-46-27.png
     
  12. James

    James Administrator Staff Member

    I can look today.. Possibly ... I keep not seeing feeders on Western Coastal Ireland which is odd too
     
  13. James

    James Administrator Staff Member

    See if that changes anything. I haven't moved one of the regions to the new server yet, just been too busy.
     
  14. James

    James Administrator Staff Member

  15. MDA

    MDA Administrator Staff Member

    But not for MLAT aircrafts :).
    This position is "estimated". It could cause some problems with tracking of some ADSB aircrafts (it can explain why once I've seen one over Norway and after few minutes over Germany).
     
  16. James

    James Administrator Staff Member

    I think doing some slicing like this will work nicely. We are getting nice overlap on the borders.

    Screenshot_2018-11-14_12-45-09.png

    Screenshot_2018-11-14_12-45-34.png
     
  17. Freqman

    Freqman Member

    @James
    Compliments!
    The matrix of Sync4 is now much faster accessible and after a reboot of my Rpi it is accepted a lot earlier.

    A lot of people have to be happy about that!
     
  18. James

    James Administrator Staff Member

    Coverage-3 over UK still getting smashed. I'll see if I can get that on a 5GHZ alone before too long.
     
  19. EDMG-1

    EDMG-1 New Member

    Yes, the sync matrix is now working much faster.
    But the overlap around the borders is only working for aircraft at high altitude. Below 10.000ft there is nearly no overlap.
    As you can see on the 2 attached pictures (comparision), currently no MLAT possible below 5000ft in south-west Germany (west of the border).
    Some weeks ago, we could see landing aircraft at Stuttgart (MLAT) till 900ft.

    Regards Stefan
     

    Attached Files:

  20. James

    James Administrator Staff Member

    Not much I can do. Get more feeders on each side of the wall ..

    Looking at the map .. that shouldn't be an issue ... maybe someone's feed in that area is down.
     
    Last edited: Dec 5, 2018