FlightAware Discussions

Is it normal to lose MLAT overnight?

It seems that every night I lose MLAT, the button on flightaware.com turns red, and then it comes back on by itself. Usually around 2AM the clock becomes unstable, with the occasional recovery. By 5:30 or so all is back to normal. Below a graph of aircraft seen with MLAT in black. Occasional MLAT planes overnight but largely quiet. The bump in activity between 4 and 430 is common.

No big deal that it disappears and reappears. Is this MLAT behavior normal? Anyone else see this?

dump1090-localhost-aircraft-6h

I have a similar number of aircrafts over night like you do and my graph looks pretty the same.

As i am normally sleeping, i do not see if the button turns red or green :slight_smile:

It helps that I travel across multiple timezones regularly.

You need enough aircraft and receivers for MLAT to work. At night the aircraft numbers get too low for MLAT to work.

Receivers can lose their location accuracy because of the lack of aircraft. The lack of receiver accuracy can then effect the ability of MLAT to work out aircraft locations.

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Are those ADS-B planes all on the ground?

With a couple of airborne ADS-B aircraft, MLAT should continue to work.

good question. I am not sure… let me monitor that.