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Anomalies in reported position above Central/Northern Germany

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  • Anomalies in reported position above Central/Northern Germany

    Since yesterday (26 dec) I started to see significant anomalies in position reports above Central and Northern Germany. Does not seem to be aircraft installation related (same aircraft reporting correctlty outside those areas)
    Does not seem to be ground ADS-B receiver related (same receiver sends correct reports at the same time as incorrect ones)
    Only correlation seems to be position in space (i.e. Central/Northern Germany) seemingly pointing to a relatively local upset to GPS signal in space; some aircraft did not seem to be affected, but then some do not use untreated GPS position in the ADS-B report, which could explain. Some similar anomalies also spotted a bit more North/East (area of Estonia)
    Has anyone else seen the same?
    Last edited by OFBleeker; 2011-12-27, 11:18. Reason: editorial

  • #2
    I have seen lots of these Anomalies in the past week in different parts of the world, i don't know if its our server or its the current Solar activity.

    Solar weather forecast

    Another thread about recent Anomalies
    All about Flightradar24.com web page and Flightradar24 apps. No discussions about feeding data to Flightradar24.


    Another member has also reported problems over Germany : http://forum.flightradar24.com/threa...ll=1#post12991
    This is the post translated with Google
    Failures over Northern Germany

    "Hello,
    I watched for days failures over Northern Germany. Flights to disappear ... just a few seconds later they are back again ... then back down. Could there possibly be a server problem? That did not used to. In the South and in other parts of Europe not observed this problem.
    Does anyone have any idea?

    VG. Torsten"

    ---------------------------------------------------------------------------------------

    Mike / Speedbird
    Last edited by speedbird1960; 2011-12-27, 15:45.
    AMS Daily Fight Information: http://schiphol.dutchplanespotters.nl/

    Comment


    • #3
      Thx Speedbird, Torsten--
      If it would be the server then it's difficult to explain for an anomaly to happen and seconds later no more. The server could possibly maltreat one or more bits in a word (either or not significant bits) but it is strange that it would do that on values for just one area (or in several specific) areas. And not on one precise location (i.e. one coordinate, like in discrete numerical upsets). Also we didn't see small errors, (like a few hunderd feet or 1 or more miles shift) but major errors (like 180 degrees, lat or lon and both in several cases) That points to missing values rather than maltreated values. No reason for the server to make such shifts versus other shifts.
      I checked several things and the only plausible explanation coud be the original position data from the aircraft, which it takes from the GPS receiver in many cases. There are some older installations where that is not the case and it might explain why some movements were OK in the "problem areas".
      Another option is [military] jamming or unintentional interference; that might explain one area of problems but not the others. If it would be indeed Sun-activity causing the [GPS] error of this magnitude, at relatively local spots and for such long periods of time, then it would be of very significant interest indeed.

      Comment


      • #4
        All about Flightradar24.com web page and Flightradar24 apps. No discussions about feeding data to Flightradar24.
        http://www.airliners.net/aviation-news/ http://www.newsnow.co.uk/h/?JavaScript=1&search=air
        http://www.liveatc.net/search/?icao=EKCH
        http://www.youtube.com/watch?v=xXYBh_ut-fo&feature ...düüüse Im Sauseschritt

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        • #5
          Gentlemen-- any news on the nature of these erratic position reports? Yesterday the problems over Germany ceased altogether from midday onwards, while the Estonia/Latvia problem area seemed to "move" to the south of Russia/East of Ukrain. It is quite intriqueing especially if any of the FR24 machinery does not show a relationship or explanation; brgds--OFB

          Comment


          • #6
            Hi OFB.

            Flightradar had its server disconnect from the radars @ 13:30, which meant each radar that had gone offline had to be restarted, it would be best to let everything settle down for a few days to see how things go.
            Last edited by speedbird1960; 2012-01-08, 15:34. Reason: Link removed
            AMS Daily Fight Information: http://schiphol.dutchplanespotters.nl/

            Comment


            • #7
              EDDV producing errors! Since this morning again. in the last week everything was perfect.

              Comment


              • #8
                Thx-- I saw several other erratic data as well (incl around EDDT, cannot correlate the actual data server); would it be possible to analyze the data? (verifying position offset during the outage to better understand the root cause). It is puzzling what the nature of the problem is (separate from plain outage); I think by now we can rule out signal in space anomalies

                Comment


                • #9
                  Hi.

                  Hopefully this won't last to long, here is the conversation from last nights Flightradar24 Chat.

                  "2012-01-06 17:50:47] (LSGG): ‹@speedbird1960› if you hear/see Mike somewhere, EDDV is testing again.

                  [2012-01-06 17:52:40] speedbird1960: ‹@(LSGG)› Is that the Radar that causes strange errors

                  [2012-01-06 17:54:06] (LSGG): yes, no vertical positions

                  [2012-01-06 17:55:34] (LSGG): means he is splitting the 1 horizontal position into hor/vertical. f.ex. 46.123 = 46 / 123

                  [2012-01-06 17:55:56] speedbird1960: ‹@(LSGG)› Thanks for that, if get asked on the Forum at least i know whats happening."

                  Mike / Speedbird
                  AMS Daily Fight Information: http://schiphol.dutchplanespotters.nl/

                  Comment


                  • #10
                    Can't the FR24 server side software "block" selective feeds?
                    Mike


                    www.radarspotting.com

                    Radarspotting since 2005

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                    • #11
                      We have sent message to EDDV about the problems
                      he is creating
                      http://www.airliners.net/aviation-news/ http://www.newsnow.co.uk/h/?JavaScript=1&search=air
                      http://www.liveatc.net/search/?icao=EKCH
                      http://www.youtube.com/watch?v=xXYBh_ut-fo&feature ...düüüse Im Sauseschritt

                      Comment


                      • #12
                        Seems to me that anyone wanting to wilfully damage FR24 can easily do so. Surely there should be a server side option to block errant feeds?
                        Mike


                        www.radarspotting.com

                        Radarspotting since 2005

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                        • #13
                          I closed the mode-S application once I realised mine was capturing rouge data, simply so it wouldn't continue uploading. One would hope it was as easy for everyone else, or turn of PP sharing if using that method.
                          Posts not to be taken as official support representation - Just a helpful uploader who tinkers

                          Comment


                          • #14
                            Today we have no easy tool for blocking a feed, but we are updating the feeding software to make it easier. Hopefully that will be ready within 2-3 weeks.

                            Comment


                            • #15
                              Perhaps no need to block a feed altogether but, for example, only filter to reasonableness; the anomalies typically show longitude jumping by some amount (seen between 10 and 180 deg) latitude soes not seem to jump so often (this is the strange part of it). If a deviation from the most recent location occurs (inside tbd bracket) then disregard the value and wait for one that fits (including compensation for aircraft motion of course). Plane plotter software appears to have quite bit of what it takes to do that from the looks of it. brgds--OFB

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