Live data from Hacker News

Flightradar24 – how it works

habr.com

151–160 of 160 posts

Re: Flightradar24 – how it works

#151

“Every civilian airliner is equipped with a special device — the so-caller ADS-B (Automatic Dependent Surveillance-Broadcast) transponder” Not true actually: in the US, ADS-B isn’t required until January 1, 2020 [1]. Also, FR24 uses radar data in the US (probably because not all aircraft has ADS-B) [2]. There are also sites, such as ADS-B Exchange [3] that provide unfiltered flight data...very helpful for tracking mi…

Even after 2020 ADS-B out won't be required in much of the airspace in the US. Only within 30 nautical miles of a class B airport, within the lateral limits of a class C airport, within class D airspace, and above 10k feet (but not below 2500 AGL I think). Even then, its only required for aircraft originally equipped with an alternator and electrical system (except in class B). Basically, it's optional in most uncont…

What is "uncontrolled airspace"?

Re: Flightradar24 – how it works

#152

Rtl-sdrs are great, probably one of the best accidental discoveries I've seen. So many things being sent out from 0-1.5GHz that you can sniff. One that I see often are the unencrypted pagers broadcasting patient details, hotel security information etc. Then you've also got amateur radio, air traffic control, GSM, key fobs, weather stations, satellites, all within the reach of anyone with $15 to spare.

I use https://github.com/bemasher/rtlamr for tracking my electric and gas usage on a minute-by-minute basis.

Re: Flightradar24 – how it works

#153
Extra notes: 1) You can share the same data to multiple sites from dump1090, not just FR24. 2) I see no difference between the $27 and $9 version of SDR. I can recommend this one: https://www.dx.com/p/rtl2832u-r820t-mini-dvb-t-dab-fm-usb-di... Running on two different computers and switching between them give the same number of planes spotted. The $9 actually seems a hint better. 3) I can recommend saving your own data to a sqlite3-database (https://github.com/yanofsky/dump1090-stream-parser). Easy to work with and under <50MB/month. Fun to write more advanced sql's to count number of time helicopter take-off, the same plane over your house etc. that FR24 can't give you.

Re: Flightradar24 – how it works

#154

Earlier quoted context omitted.

"Data monopoly" implies FR24 have exclusive use and control over the ADS-B feeders. This simply isn't the case. There's nothing stopping you feeding your data to other sites/apps. Also (as is the case with flight aware), all users providing ADS-B data get free subscriptions to the paid for parts of FR24s service. Building an app, maintaining a website (that has something like 2 million daily users iirc) and building…

> There's nothing stopping you feeding your data to other sites/apps Except the TOS, if you're using one of their receiver kits.

Don't use one of their kits...

Re: Flightradar24 – how it works

#155
post #2

Interesting tidbit from the article—apparently flightradar24 doesn’t show business jets or military planes.

For FR24, commercial bizjets are shown (i.e. those operated for charter). It's only privately owned and operated bizjets that can be hidden if the owner requests it.

Re: Flightradar24 – how it works

#156
post #52

Earlier quoted context omitted.

In practice, anything that can be described as an "airliner" is a large commercial aircraft and flies above 10k regularly. Probably required to have ADS-B.

Oh whoops, I misread as "airplane"

AU: Another good example where it'd pay off to use the 'FQDN', transport category aircraft.

Re: Flightradar24 – how it works

#157
post #151

Earlier quoted context omitted.

Even after 2020 ADS-B out won't be required in much of the airspace in the US. Only within 30 nautical miles of a class B airport, within the lateral limits of a class C airport, within class D airspace, and above 10k feet (but not below 2500 AGL I think). Even then, its only required for aircraft originally equipped with an alternator and electrical system (except in class B). Basically, it's optional in most uncont…

What is "uncontrolled airspace"?

https://en.wikipedia.org/wiki/Uncontrolled_airspace

Re: Flightradar24 – how it works

#158
Flightradar24 has a nice interface and apps but it is CENSORED. Not all airplanes transmitting ADS-B are visible there.

Fortunately there is https://www.adsbexchange.com which offers unfiltered data. You can set up a receiver so that it runs dump1090 separately and forwards it to both using Beast protocol. You can also participate in adsbexchange M-LAT.

Re: Flightradar24 – how it works

#160

Earlier quoted context omitted.

Yes. A cheap DVB-T dongle supported by RTL-SDR along with https://github.com/MalcolmRobb/dump1090 or similar will allow this, but bear in mind that something like this should really not be used in any situation where flight safety depends on it.

That uses a google map which is nice, but I'd prefer something offline.

Should be very easy to swap the google map out for something offline. You can still use the remaining 99% of the tool which does the receiving/decoding/interpreting of the signals.
Post reply on HN