Got an ADS-B receiver in Ireland? Help map the sky over your town

Why the map is quieter outside Dublin

Point Skylark at a plane over Dublin and it will tell you what it is, where it is going and how high it is. Try the same over Cork, Galway or Sligo and, too often, the sky looks quieter than it really is.

That is not the planes. It is the receivers. Skylark only knows about an aircraft when a receiver on the ground hears it, and in Ireland most of the receivers feeding Skylark are around Dublin. If you already run one somewhere else on the island, you can change what everyone near you sees this evening.

What a receiver does

Most airliners broadcast their own position, height and speed on 1090 MHz. That broadcast is ADS-B Out, and anything that listens to it is ADS-B In [1]. A small aerial and a USB radio plugged into a Raspberry Pi can listen, and a decoder such as readsb turns the signal into aircraft with positions [2].

Thousands of hobbyists do exactly this and share what they hear with networks like Flightradar24, FlightAware, adsb.lol and ADS-B Exchange [3]. Skylark works the same way: every plane on the live map was heard by a receiver someone set up. New to it? Start with what ADS-B is and your first receiver in the field guide.

Already feeding someone else? Keep doing it

Skylark is built to sit beside what your Pi already runs, not to replace it [4].

• One command. Run curl -fsSL https://skylark.watch/feed/install.sh | sudo bash. It prints a code like KXQ7-M4TB; type it at skylark.watch/pair and you are done. No keys to copy and paste.
• It leaves your setup alone. It only reads your decoder’s aircraft.json. It never opens the radio, installs a decoder or touches another feeder’s config, and it runs as its own locked-down user [4].
• It finds your decoder. readsb and dump1090-fa, including the usual paths for PiAware, ultrafeeder and adsb.im [4].
• It tells you what is wrong. sudo skylark-feeder doctor checks the decoder, the clock, the connection and your station, and names the fix for the first thing that fails.
• It comes back out cleanly. sudo skylark-feeder uninstall removes the forwarder, its key and its user.

Read the script before you run it if you like. It is published next to its checksum, and the feeder toolkit is MIT-licensed [4].

What you get back

• Your own station workspace: what your receiver hears right now, coverage by altitude over 1, 7 and 30 days, range in every direction, a ten-minute replay, and the reason behind every rejected position [4].
• Your planes on the map: once your station is approved, your positions fill gaps on skylark.watch and in the Skylark iPhone app for everyone in Ireland.
• Your local sky, remembered: approaches, go-arounds and estimated noise for where you live, built from the network you are part of.
• Open data if you want it: you can opt in to publish your daily observations under the ODbL licence [4].

Your location stays private

Your antenna’s exact position is never published. Skylark takes direct 1090 MHz ADS-B positions only; MLAT, TIS-B and database details stay on your receiver [4]. Every new station is reviewed before its data goes public, and you can pause at any time.

Where a receiver helps most

Right now: Cork, Galway, Limerick, Belfast, Derry, Sligo, Waterford, Kerry and the midlands. A receiver on a hill, a high roof or in an attic in any of those places makes a visible difference to what everyone around you sees. Open the live map to see how thin the sky is where you live.

No receiver yet, but you want Skylark where you live? Add your area to the list and we will tell you when it is covered.

What it needs

Linux with systemd and Python 3.9 or later: Raspberry Pi OS, Debian, Ubuntu or DietPi. Your decoder must label direct positions ("type": "adsb_icao"), which readsb and dump1090-fa 4 and later do. The old dump1090-mutability inside some Flightradar24 images does not, so install readsb beside it [4]. On a Pi that already runs a decoder, it takes a few minutes.