MLAT - how can i see where Altitude numbers come from


i’m still wondering if/how/where i can see where the altitude data came from those three possible:

  • from aircraft transmitted
  • from aircraft transmitted and corrected by mlat computing
  • only based on mlat computing

in aircraft.json i find different behavior in field mlat:

  • lat lon altitude track speed vert_rate
  • lat lon track speed vert_rate

is this the right place and if so single place where one can find the answer of my question?
what exactly do the two behaviors stand for?



You could look at the raw beast messages to distinguish these cases. Mlat messages are easily recognized by their timestamps.


yes - thanks for the reminder i again forgot about the mlat-timestamps! but it were nice if you could explain me why and when you set those parameters (lat lon altitude track speed vert_rate ) into mlat-field and what that means. when i have to do this and in addition dive through the code behind it would probably cost me hours :slight_smile:


The code is the definitive reference here, I think you’ll just have to spend the time to understand it.


ok - when i have to - i will :slight_smile: but one thing is sure - if there were a user ranking for dump1090/mlat-client/piaware code diving i’d be the number one at least if parameter were the time spent …