Dumb question du jour

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elaw
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Dumb question du jour

Postby elaw » Wed May 24, 2023 8:34 pm

Is Flightradar24 supposed to show all aircraft traffic, or only planes with transponders turned on, or only ones with ADS-B, or what?

I'm sitting here listing to LiveATC's feed of the tower at my friendly local airport (KLWM) and 75% of the aircraft I hear them talking to don't show up on FR24.
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3WE
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Re: Dumb question du jour

Postby 3WE » Thu May 25, 2023 2:28 am

Is Flightradar24 supposed to show all aircraft traffic, or only planes with transponders turned on, or only ones with ADS-B, or what?

I'm sitting here listing to LiveATC's feed of the tower at my friendly local airport (KLWM) and 75% of the aircraft I hear them talking to don't show up on FR24.
In my experience maybe 25% of light planes don’t show up on FR…

I INFER that ADS-B is not_always required/used.

I THINK FR requires ADS-B data.
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Gabriel
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Re: Dumb question du jour

Postby Gabriel » Thu May 25, 2023 1:40 pm

FR24 tracking requires ADS-B.

There is a network of ADS-B receivers installed by volunteers in their homes. The equipment is an antena that you should place as high as possible, a "box" that connects to the antenna and to the volunteer's PC, and the volunteer's PC which must have a specific software installed and running and an active internet connection to stream the data to FR24. (I know because I was asked to volunteer when I was living in Buenos Aires).

This ground receiver is passive (meaning it is just a receiver). Whenever the transponder of an ADS-B airplane is pinged by an ATC SSR (secondary radar) or by another's plane transponder/TCAS/ADS-B, it will emit the burst of data that contains location, airspeed, heading, altitude, vertical speed, etc... These FR24 ground receivers don't interrogate but just listen to the replays to other's interrogations.

The ADS-B data is also listened by a network of salletes. Unlike the ground receivers, the satellites are not under the control of FR24, but since a couple of years ago this satellite-collected data has been made public in real time. FR24 uses the ADS-B satellite-collected data to show the planes that are not in range of their ground receivers.

Yellow planes are being tracked by ground receivers. Blue planes are being tracked by satellite. That's why you typically see continents full of yellow and oceans full of blue.

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Re: Dumb question du jour

Postby elaw » Thu May 25, 2023 2:08 pm

Okay thanks! I actually know about the ADS-B part - I've actually applied to see if they'll send me a receiver (I live about 1 mile from KLWM). But for some reason I thought they tapped into the FAA's radar network also.

Is there another website where I can see that data? Meaning in an "all the planes in the sky" sense... I know of sites like Flightaware where you can track a specific flight. Basically I'm looking for something where if I see a plane fly over my house, I can find who/what it is.

I wonder... does ADS-B ever broadcast its data without being "pinged"? You'd think they'd have some mechanism like that for aircraft that are (for example) over the ocean with no ground tracking station or other aircraft nearby to trigger the transmission.
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Gabriel
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Re: Dumb question du jour

Postby Gabriel » Sat May 27, 2023 5:45 pm

But for some reason I thought they tapped into the FAA's radar network also.
Could be, this info I gave above about ground receivers is more than 10 years old.
Is there another website where I can see that data? Meaning in an "all the planes in the sky" sense... I know of sites like Flightaware where you can track a specific flight. Basically I'm looking for something where if I see a plane fly over my house, I can find who/what it is.
Flightaware has the same type of map view as FR24, where you can see all the planes in the area. If you zoom in to see a zone of some miles around your house, you would be able to see every plane flying through that zone (as long as they have ADS-B and there is a receiver from the network listening to it) and you you hover over with the mouse the airplane icon you get info of the flight and if you click on it you get more info.

This applies to both FR24 and Flightaware.
I wonder... does ADS-B ever broadcast its data without being "pinged"? You'd think they'd have some mechanism like that for aircraft that are (for example) over the ocean with no ground tracking station or other aircraft nearby to trigger the transmission.
I don't know, good question.

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Re: Dumb question du jour

Postby ocelot » Mon May 29, 2023 4:49 am

This is not_offtopic. Ironings and bannings will commence shortly.


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