FlightAware Discussions

Maximum Report of Aircraft to ADS B

At a time maximum how many Aircrafts can report to a single ADS B Feeder?
What’s d maximum capacity of a single ADS B Feeder?

That’s not really how it works.

There is a practical limit of the number of messages per second received.
That depends on the hardware, on a normal rtl-sdr stick in Europe with 200 nmi + range in all directions it’s probalby 1600 to 1800 messages per second.
The ModeS Beast or the airspy probably peak out at around 2400 messages per second or more.

Now the 1090 MHz frequency is also congested due to Mode AC messages which are not part of the message count.

ModeS message rates for the same number of aircraft are considerably lower outside of Europe.
Something to do with interrogating radars.

Now would you say 1 position every 30 seconds does still count as the receiver receiving the airplane?

By that metric @keithma with his receivers in the UK in prime spots tops out at around 250 planes with position.

But you could increase that if you were to make 2 or more directional antennas and used individual receiver on them.
That way you avoid overlapping messages from different directions in the sky (antennas cover a sector of the sky).

Anyway if the amount of messages per plane per 10 seconds becomes too low, then you don’t get good positions anymore and while you may still say that you “receive” that airplane in all practical terms you are not receiving it.

In the US with the secondar radars interrogating at lower frequency you get lower message rates but more of the messages are actual ADS-B messages (with position).
So in a good spot you can probably receive 400 or even 500 aircraft at the same time.

The limit for most feeders are terrain and the number of aircraft in direct line of sight.

The most aircraft I’ve ever seen at one time is 467 but I didn’t get a capture of that. Here’s a shot of 451 aircraft but I’m only actively receiving positions from 251 of those.

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Immense THANX for d reply.