My (very general, handwavey) understanding of the way FlightAware handles MLAT is that the system groups various feeders in an geographical area into a single group and uses data from those feeders to compute MLAT positions. However, data from feeders in different groups – even if they’re physically relatively close and have overlapping coverage areas – don’t get used. Is this correct?
My location, #11261, gets good coverage over nearly all of Switzerland, eastern France, southern and south-western Germany, Luxembourg, and a little bit of western Austria. Maximum range is around 300mi. However, it looks like certain flights (usually NATO military flights in Germany or France) are in different MLAT groups from my feeder and although I can see the Mode-S data (call sign, ICAO hex ID, and altitude) those planes show up in the dump1090 web interface with only a white background, not the blue indicating my feeder contributed to an MLAT location.
I occasionally see other NATO and Swiss Air Force flights show up with MLAT positions, so it’s not due to military flights being blacklisted from MLAT processing.
Is there a map of MLAT zones in Europe? Is it possible to have my feeder be a part of several zones to help contribute to more locations?