FlightAware Discussions

Is MLAT useless now that ADSB is required?

What purpose does MLAT serve for FlightAware now that ADSB is required, except to capture Super Cubs without a battery?

It seems a relic of the past.

In the US it is only mandatory where Mode C was. There are plenty of locations that don’t require ADS-B.

I reread this https://www.aopa.org/go-fly/aircraft-and-ownership/ads-b/where-is-ads-b-out-required

But the percentage of planes who ONLY go there is really small.

Still useful in areas experiencing GNSS interference/denial. Mostly exercises in US airspace.

How much do the GPS notams (military exercises) affect FlightAware? The ground radius are small.

The impact at altitude can be hundreds of miles in radius, impacting many flights through it.

Also useful for:

  • the 94% of the land area of the Earth that isn’t the US where there are different ADS-B requirements
  • areas without UAT receiver coverage
  • handling aircraft with transponder faults

FlightAware has a partnership/data feed with Aerion right? That gets rid of the ground interference problem in US/Canadian airspace for airplanes with antenna diversity.

The rest of the world, I understand. But for the US, that’s lot of bandwidth and compute to be saved, assuming FlightAware agrees that WAAS has integrity.

Space-based ADS-B doesn’t help if the aircraft itself doesn’t have a good GPS position available. The interference is on the GPS band, not the ADS-B band.

You guys are the experts, but the airplanes with antenna diversity have an antenna on the ceiling that would block ground based jamming wouldn’t it?

Never mind, I just thought about it, GPS antennas are on the top of the fuselage as a requirement to talk to the satellites. If a NOTAM is required then it must be possible to overcome the fuselage blocking the ground.

We’re not all in the US rolleyes

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