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.
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.
They also started out with a fairly expensive premium app, and then jettisoned it in favor of a subscription-based service, leaving everyone who bought the app high and dry.
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.
That gets into the very tricky idea of "What is commercialization?" If you use a Creative Commons works that's BY-NC on your blog, but your blog runs ads, is it now commercial? What if it's funded by Patreon? That's why Wikipedia doesn't allow NC and the premise behind the Free Culture licenses.
Last time I looked closely it was similar in North America and Europe. Asia, Africa, and over the oceans had some pretty big gaps.
There's also no delay on the data, although I think Flightradar and Flightaware dropped the 5 minute delay they used to have. Flightradar censors a lot of corporate jets and military/law enforcement aircraft but I don't think Opensky does. In fact one of either Opensky or adsbexchange even has a special flag in their REST API for "interesting" aircraft
> Flightradar censors a lot of corporate jets and military/law enforcement aircraft
Yes, this is disappointing. In the past I had seen military planes on there. I even saw fighters practising dogfighting over the North Sea. But more recently I've seen interesting aircraft fly over, such as large four-engine planes at altitude outside of normal commercial flight paths, but they just don't appear on flightradar. It's stupid because I can see the damn thing. I need to figure out an alternative to flightradar, it seems.
Some activists were using this kind of service to track dictator's flights to track stolen money [1]. If said dictator's can block their aircraft, the misappropriated funds would be easier to sneak out of the country.
ADS-B Exchange [0] has a tag for military aircraft, right now it's showing a whole bunch of military aircraft (German, Belgium, Norway, Netherlands, UK, US) over central Europe.
Note that even the Swedish spy plane is using Ads-b while flying along the baltic International border zone taunting Russia but the migs answering the taunt is not. Also flying dangerously close to the spy plane (10 m reported once). However the US spy planes are also mostly flying with the transponder on there.
The delay was a rule from the FAA for radar data provided by them, ADS-B plots have always been real-time. I am guessing (from the lack of orange icons anymore) that the ADS-B coverage is good enough now that FR24 is not using FAA feeds any more.
"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 out backend infra to support the huge amount of incoming data and turn it into something greater than the sum of its parts costs money. What many people don't realise is the data you see on FR24 is not simply derived from ADS-B broadcasts. Data like fight numbers comes from other licensed sources; MLAT triangulation is done at FR24's end; telemetry data for areas without community ADS-B coverage comes from partnerships with radar operators, airports (and soon satellite, when Aireon is active) etc.
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.
Not sure if you mean easy to use interface for contributors or for users. I can only judge the second, and the website is "meh"... it's kind of slow and the UI and design is underwhelming.
In any case, being good at what they do definitely helps, but network effects is also a factor. They have the best data coverage, therefore new contributors will mainly chose them over a hypothetical competitor with a slightly better support and user interface.
This discourages new competitors to even try entering the market, which has the usual downsides of a monopoly market such as less innovation.
I thought it would be cool to have some kind of gateway service that collects the data and then sends if off to adsbexchange, flightradar and others but apparently it's not so easy.
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, and ADS-b Exchange uses netcat to send it to their server. You can use the ADS-B Receiver Project [2] to install everything needed.
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.
Unfortunately, there is no good solution for this. Either you rely on the time settings of the sender or on the time needed to transmit the data and on the time the data gets transmitted.
If we assume the sender is not malicious, a properly configured NTP client ("the time settings of the sender") would probably suffice. If the sender is malicious, unless you somehow make the "signal + timestamp" from the receiver non-modifiable from the receiver to the service, you've lost anyway.
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.
As noted by another comment, AIS signals are being broadcast line-of-sight from the ground so you need more receivers than you do to track airplanes. OTOH you only need the receivers on the coastlines and on major inland waterways, not over the whole earth's surface. (If you want to track a ship mid-ocean, you'll need a satellite. Those exist but cost $$.)
You are always welcome to feed more than one service. Even when you get a free receiver from the company, nothing stops you from repurposing the data and feeding elsewhere.
