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Flightradar24 – how it works

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Re: Flightradar24 – how it works

#101

Not a big fan of "data monopolies" like Flightradar24. It's as if OpenStreetMaps was a private company that capitalizes on being first into the space and having a community of contributors willing to supply data to a private company for free. I hope an open data project such as https://www.adsbexchange.com/ wins in the long-term.

Note that the OpenStreetMap Foundation is a private company (it's not a for profit company, but it's organized as a company under UK law), probably is the first (at least large scale general purpose) crowd sourced map, and supplies data for free to anyone that meets the terms of the ODBL.

Re: Flightradar24 – how it works

#102
I always thought it would be interesting to package all of this up and sell it to small operators. For example, a flight school could deploy a small scale RTL-SDR based ADS-B/MLAT system for tracking of their aircraft. The geographic area required to cover would be relatively small. Perhaps a 50 nm radius around the base. Of course they could also just fill in the gaps of something like Flightradar or ADS-B exchange but sometimes it’s nice to own your infrastructure.

Re: Flightradar24 – how it works

#103

Not a big fan of "data monopolies" like Flightradar24. It's as if OpenStreetMaps was a private company that capitalizes on being first into the space and having a community of contributors willing to supply data to a private company for free. I hope an open data project such as https://www.adsbexchange.com/ wins in the long-term.

Completely agree. FR24, along with FlightAware, Radarbox24 and Plane Finder has built a business of monetizing free, crowdsourced data. For FR24 there's been multiple requests by the community to for an API, some willing to pay, but they've refused every time. I don't understand why people are eager to feed into those closed network.

ADSB Exchange on the other hand is built with an open premise, runs off donations, and encourages third-party app and value add to build off their API.

Re: Flightradar24 – how it works

#104
post #103

Not a big fan of "data monopolies" like Flightradar24. It's as if OpenStreetMaps was a private company that capitalizes on being first into the space and having a community of contributors willing to supply data to a private company for free. I hope an open data project such as https://www.adsbexchange.com/ wins in the long-term.

Completely agree. FR24, along with FlightAware, Radarbox24 and Plane Finder has built a business of monetizing free, crowdsourced data. For FR24 there's been multiple requests by the community to for an API, some willing to pay, but they've refused every time. I don't understand why people are eager to feed into those closed network. ADSB Exchange on the other hand is built with an open premise, runs off donations, a…

Well, we can do both. FlightAware has nice tutorials and client software for setting up an ADSB feeder on a Raspberry Pi, but I feed to ADSB Exchange as well with minimal extra effort.

Re: Flightradar24 – how it works

#106
In North America ADS-B is pretty rare except on the coasts where international flights pass through more frequently. If you are not on the coast and look at the logs of your flightradar24 receiver you will see that 99% of the traffic are MLAT rf direction finding logs from mode-S transmissions with no GPS data used. But it's still easier to call it an "ADS-B" receiver because no one knows that MLAT is.

Re: Flightradar24 – how it works

#107
post #103

Not a big fan of "data monopolies" like Flightradar24. It's as if OpenStreetMaps was a private company that capitalizes on being first into the space and having a community of contributors willing to supply data to a private company for free. I hope an open data project such as https://www.adsbexchange.com/ wins in the long-term.

Completely agree. FR24, along with FlightAware, Radarbox24 and Plane Finder has built a business of monetizing free, crowdsourced data. For FR24 there's been multiple requests by the community to for an API, some willing to pay, but they've refused every time. I don't understand why people are eager to feed into those closed network. ADSB Exchange on the other hand is built with an open premise, runs off donations, a…

There's probably not much stopping FR24 from feeding off of ADSB Exchange. This happens in the weather world, where data from community-managed CWOP weather stations ends up in the hands of commercial weather data services, who normalize the feeds and incorporate them into their forecasting products.

Re: Flightradar24 – how it works

#108
post #56

In Germany receiving ADS-B used to be illegal (I don't think it has changed, but I did not verify.) In Finland receiving as such is not illegal, but forwarding the information is. In both cases the reasoning is that this information is not directed to the public. Whether anybody has ever been prosecuted I have no idea.

It looks like it was legalized a while ago: https://lawfactory.de/PDF/Funkamateur_2010_03.pdf (in German)

Re: Flightradar24 – how it works

#109
post #51

Earlier quoted context omitted.

Do you mean collect data from multiple receivers and send it off to various services from one computer? That messes with MLAT [0] calculations and shouldn't be done. If you want to send data to multiple services from one receiver all you need is to install the feeder for each service. Most uses dump1090 [1], but Flightradar24 uses their own. Dump1090 sends data in different formats to various local ports by default,…

Do you have more detail on how collection messes with MLAT calculations? It seems like for triangulation purposes, each device should produce some precise timestamp that is not affected by store-and-forward transmission.

I don't think the programs are made to handle that use case. At present you register your receiver's location with the server once and send packets as they arrive, that server doesn't know that your packets are from multiple receivers at multiple locations.

https://discussions.flightaware.com/t/aggregation-of-dump109...

https://github.com/mutability/mlat-client

Re: Flightradar24 – how it works

#110

Earlier quoted context omitted.

Do you mean collect data from multiple receivers and send it off to various services from one computer? That messes with MLAT [0] calculations and shouldn't be done. If you want to send data to multiple services from one receiver all you need is to install the feeder for each service. Most uses dump1090 [1], but Flightradar24 uses their own. Dump1090 sends data in different formats to various local ports by default,…

If you aren't trying to send MLAT data to more than one server, it isn't an issue. You can do MLAT to, say, adsbexchange, and non-MLAT to flightradar24.

You'd still need to send the mlat messages from each receiver though, you can't aggregate them from one computer since there's no position included in the sent messages. And I don't know why it would be a problem to feed from each receiver, they need connectivity any way.
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