I was tinkering with my web interface modifications and tried to get rid of MLAT positions for aircraft on ground because those mess up the ground tracks of aircraft as they lack the precision for airport display.
Sadly it seemed i couldn’t filter out all of the MLAT positions while the aircraft was on ground.
Started up a separate dump1090-fa that only received the non-MLAT data for comparison.
The ADS-B positions can indeed be intermittent.
How long before the decode logic would use a MLAT position after doing a valid relative CPR?
124 F(cpr_odd, 60, 70); // ADS-B only
125 F(cpr_even, 60, 70); // ADS-B only
I’d assume 60 seconds before MLAT CPR would be accepted after an ADS-B CPR is received?
I think i’m seeing MLAT positions sooner than that.
So that could happen if one were to receive only odd ADS-B CPRs and the even ADS-B CPR were to be older than 60 seconds, a relative CPR would be done on an even MLAT CPR?
Hmm i got sidetracked, that isn’t really the problem.
The problem is the MLAT derived position isn’t marked as MLAT in the json data.
Otherwise my webinterface would discard it (for ground positions, but i’ve also tried discarding all json positions marked with mlat, the MLAT positions still get through)