Time needed for MLAT sync

Hi!
How much time before a ModeS plane transit over 3 receivers the receivers have to be in sync? I often see synced with 4 receivers but no positions are computed…
And furthermore has the ADSB traffic to be the same on all receivers o a receiver just need an adsb traffic to sync with?

Thanks

Each pair of synchronized receivers needs to see the same ADS-B aircraft to synchronize.
The synchronization only stays valid for approx 30 seconds.

So basically MLAT with three receivers (put A,B,C) is ready if:

1)a receiver shares a common ADSB traffic with ONE another receiver (eg: a with b and a with c) or (a with b and b with c)
2)Mode S traffic is seen by A B and C

In this situation A or B orC is synced with 3 receivers.

Right?

Thanks again

In that case, there is a group of 3 receivers available to do mlat. (That’s not enough for results - you need 4).

Each receiver reports only the directly synchronized receivers on the stats page, so in your first scenario (a with b and b with c) A will report 1 synchronized, B will report 2 synchronized, C will report 1 synchronized.

ok.
Thanks again