Status and sources
This page says plainly what the live view shows as real, what it estimates, where each piece of data comes from, and what it must not be used for. TowerScope is an independent demo. It is advisory only and not an FAA system.
Feed health right now
| Airport | Feed | Aircraft | Last update | Polls ok | Polls failed | Recorded on disk |
|---|---|---|---|---|---|---|
| Loading | ||||||
Real
- Aircraft positions, altitude, ground speed, track, vertical rate, callsign and type as broadcast by the aircraft (ADS-B) and received by volunteer ground stations. Each position fix shown as a dot on the charts is one of these.
- The time of each fix. It is the time we polled the network minus the age of the position the network reported.
- Runway positions and lengths from OurAirports (public domain).
- Terrain from AWS Terrain Tiles. Buildings and roads from OpenStreetMap.
- Recorded history: every poll of the three airport areas is written to disk and kept for 72 hours. Failed polls are recorded too, which is how gaps are shown.
Estimated
- Smooth motion between fixes. Fixes arrive every 8 to 15 seconds in our recording, so the path between them is a curve we compute. The live view runs about 10 seconds behind real time so it can interpolate instead of guess ahead.
- Flight deck pitch (climb angle plus a typical 3 degree angle of attack) and bank (from turn rate). Neither is recorded aircraft attitude.
- Surface, arrival, departure and overflight labels. They come from altitude, climb rate and heading, not from flight plans.
- Tower cab eye height. Kept as an estimate; the source for each cab position is shown in the cab view and below.
- Altitude reference. Barometric altitude is drawn as if it were height above sea level. It can be off by about 100 feet.
Not available
- Ground vehicles, and any aircraft without an ADS-B transmitter or outside receiver coverage. Low altitude and surface coverage has gaps.
- Radar, ASDE-X, SWIM or any FAA operational data. No flight plans, no clearances, no voice.
- Surveyed tower cab geometry. The cab positions are public map data, not a survey.
- Aircraft flagged by the network as blocked for privacy (PIA or LADD). We drop them. Registration numbers are not stored or shown.
Limits of use
- Demo and advisory only. Not for separation, sequencing, navigation, emergency response or any operational decision.
- Not an FAA system. Not equivalent to the FAA Surface Awareness Initiative, ASDE-X or any vendor product, and not eligible for any federal funding program.
- A replay is a reconstructed estimate from community receivers. It is not an investigation record.
Sources and licenses
| Data | Source | License and how we comply |
|---|---|---|
| Live and recorded aircraft | adsb.lol public API, polled from our server | ODbL 1.0. We attribute on every screen. Exports are a derived database; if you share one, share it under ODbL 1.0 with the same attribution. Our polling is slow on purpose (one request every 8 to 15 seconds per airport). |
| Map, buildings, roads | OpenStreetMap via a Protomaps extract (build 2026-10-10) | ODbL 1.0. Attribution on screen. Served from our own server as a small tile file. |
| Terrain | AWS Terrain Tiles | Open data with attribution. Loaded directly by your browser. |
| Runways, airport reference points | OurAirports | Public domain. |
| Tower cab positions | OpenStreetMap: KIAH way 639097416 (control tower, height 102.4 m), KDWH way 958053124 (aircraft control tower, height tag 71 with no unit). KCXO has no tower in OpenStreetMap, so its cab is a nominal point. | ODbL 1.0. Eye heights are our estimates (KIAH 94 m, KDWH 18 m, KCXO 16 m). The KDWH height tag is ambiguous, so we assume feet. |
| Software | MapLibre GL JS (BSD-3), three.js (MIT), PMTiles (BSD-3) | Kept with their notices. |
| Not used | Google Photorealistic 3D Tiles, Cesium ion, OpenSky Network, Flightradar24, ADS-B Exchange | Their terms bar or restrict aviation, operational or commercial use without a written license. We do not use them. |
How the pieces work
- Live view. Our server polls adsb.lol for each airport area and serves the latest picture. Your browser asks for it every two seconds and draws it.
- Flight deck. Pick an aircraft, then Fly with it. The camera sits on the aircraft and looks along its track. The speed tape, altitude tape, heading tape and vertical speed are the broadcast values.
- Tower cab. The camera sits at the tower position at the estimated eye height. Drag to look around. Track selected points the view at the aircraft you chose.
- Replay. Pick a recorded window. The map, the charts and the timeline use one clock. Amber hatched bands mean nothing was recorded then. Export gives you the data behind the window with the attribution above.