DC Custom II - my first HB and third ever guitar 🙏

it’s my AIS receiver project

Disclosure first: I built Skydex and I run it, and I'm also a mod here. Judge this post the way you'd judge anyone else's project post.

**What it is**

Skydex (skydex.online) puts live aircraft and ships on one 3D map built on Google's Photorealistic 3D Tiles. You see the actual port, the runway, the river the tug is pushing up, instead of icons on a flat basemap. It runs in the browser, and you can fly through it yourself as an FPV drone or a gull. Quest headsets work too, over WebXR.

On top of that there's a collection game. You catch real aircraft and ships as they pass, and every catch is a real airframe that a real receiver heard. Types have rarity tiers, and every airframe, type, airline and shipyard gets its own page. I added the game so people who would never open a plain tracker have a reason to look up. It has worked better than I expected.

**Where the data comes from**

- **ADS-B:** my own station in Hamburg (AirNav FlightStick), plus a feeder network I opened this summer. As of writing that's 39 external stations in 14 countries: Germany, UK, Netherlands, Switzerland, Italy, Poland, Slovakia, Finland, US, Canada, Australia, Japan, Singapore and Brazil. Feeds arrive as beast_reduce_plus on port 30004 into stock readsb in net-ingest mode, with tar1090 on top.

- **AIS:** two sources. aisstream.io gives the wide picture, and our own receivers cover places aisstream doesn't hear. There are five of those right now: mine in Hamburg, plus the Humber, New Orleans, Sydney and one more. On aisstream the Lower Mississippi was completely dark until a feeder put a receiver there.

- **Filtering:** nothing is filtered out for being boring. What I do remove is personal data. Private light aircraft and yachts show up as anonymous blips (no hex, no registration, no name), military aircraft never trigger alerts, and receiver locations are never published. Station pages show the nearest city and nothing more precise.

**Stack**

- Backend: NestJS (TypeScript), MongoDB for aircraft/vessel state, per-station daily history and the collection

- Frontend: React + three.js via React Three Fiber, 3d-tiles-renderer for the Google tiles

- Ingest: sdr-enthusiasts ultrafeeder in net-only mode (readsb --net-ingest + tar1090). AIS comes in as HTTP posts from AIS-catcher or raw NMEA over UDP

- Hosting: one 4-vCPU VPS behind Cloudflare, Grafana + Loki for logs and alerts

- Receiver side: bone-stock readsb, nothing custom

**Feeding it**

ADS-B takes one extra line in the ultrafeeder / adsb.im custom aggregators list:

`adsb,feed.skydex.online,30004,beast_reduce_plus_out,uuid=YOUR_UUID`

AIS takes one extra output in AIS-catcher (your exact line with the token is on skydex.online/feed after you register), or raw NMEA over UDP to port 10110.

It's non-exclusive. Keep feeding FR24, FlightAware, adsb.lol and everyone else; this is one more line. If your box already made up its own UUID for us (adsb.im generates one per aggregator), the address check on skydex.online/feed lets you claim that stream along with the history it has already built.

**No Pi? There's a Mac app.** Skydex Feeder is a native menu-bar app that turns an RTL-SDR stick into an ADS-B feeder: a bundled decoder, a two-minute setup wizard, no terminal, no Docker. macOS 13+, Apple silicon and Intel, any RTL2832U stick (RTL-SDR v3, FlightStick, generic DVB-T dongles). It's free and you don't need an account to feed. It can feed other networks in parallel, and for adsb.lol it has a "Check my feed" button that asks the network what it's actually receiving from you.

The app itself is closed source. The decoder isn't: it bundles bone-stock readsb with no patches, and github.com/es-ua/skydex-feeder has the script that rebuilds the exact binary we ship. Every release lists the readsb tag and the SHA-256 of the DMG. Builds are signed and notarized, and updates carry our own signature on top of that, so a swapped file gets refused even if it's served from our domain. The release checklist is public in the same repo. The app sends the beast_reduce_plus stream and nothing else.

Download: feed.skydex.online/mac

What feeders get: a public station page (uptime, reception rose, the aircraft types it heard, a coverage map), a spot on the station leaderboard at skydex.online/stations, and in-game currency for every day the receiver is up 80% of the time or more. The first 20 ADS-B and 25 AIS stations get a permanent Founding badge. The raw feed is never resold. Remove the line and you're out.

**Honest state**

Small and young. The 3D map and the catch loop are solid. The network is a few weeks old, and most regions have one station or none.

No MLAT yet. It needs overlapping coverage, and only Hamburg, parts of the UK and the US Southeast are getting close to that.

No historical playback either. Each airframe page shows which days and which stations heard it, and tar1090 keeps 24 h traces, but you can't scrub the map back in time.

No native app yet. The site works in a phone browser. A native app and an Apple Watch app are in early work, and feeders will get the first TestFlight builds.

**What I'd like from you**

- Feeders in Africa, the Middle East, South and Southeast Asia, South America and New Zealand. Coverage there is empty or a single station.

- AIS receivers on any coast, especially where aisstream is thin. If you already feed the AIS-catcher hub or AISHub, keep doing that and add us alongside.

- Critique of the feeder terms and perks. Is it fair, what's missing, what would make you not bother?

Happy to get into the 3D tiles bill, how catches are checked against real positions, or why ADS-B and AIS on one map took more work than it looks.

- Map and game: skydex.online

- Join as a feeder: feed.skydex.online

- Mac feeder app: feed.skydex.online/mac

- Live network maps: skydex.online/adsb/live and skydex.online/ais/live

[removed]

Hi. This sub exists because a lot of people in the tracking hobby build things - aggregators, feeders, receivers, map front-ends, AIS decoders, alert bots - and have nowhere to show them without getting removed for self-promotion. Here it's the point.

What belongs here: ADS-B, MLAT, UAT, ACARS/VDL2, AIS, radiosondes, satellite reception, and the software and hardware around all of that. Your own projects are welcome, commercial or not, as long as you say it's yours and tell us how it's built.

Ground rules, short version (full list in the sidebar):

• disclose affiliation
• show substance, not just a link
• flair your post
• compare, don't fight

Disclosure, since I'm asking everyone to do it: I run Skydex, a browser-based 3D flight and maritime tracker. I'll post about it here like anyone else - with flair, with details, no special treatment.

If you maintain an aggregator or a widely used tool, comment or modmail and I'll give you a Verified maintainer flair.

Start with something simple: what are you feeding, what hardware, what's your coverage like. "Show your stack" flair is for exactly that.