Zenith

Watch live satellites overhead on your map. Zenith computes real-time satellite positions from orbital data and shows them moving across QGIS — track your current map view, or draw an area to watch. Live only; no history replay.

Zenith is one of three sibling plugins built on the same live-tracking engine — a pluggable data-source layer, a moving-point map layer, clustering and identify — covering sea, sky and space:

• Wake — marine vessels (AIS)
• Contrail — aircraft (ADS-B)
• Zenith — satellites (this one)

How it works

Satellites don't broadcast their positions the way ships and aircraft do. Instead their orbits are published as TLEs (two-line element sets) — a compact set of orbital parameters. Zenith fetches those, free and keyless, from CelesTrak, and then computes each satellite's position on your own machine using the SGP4 propagator, updating every second.

Computing locally rather than receiving a feed has real advantages:

• No rate limits — positions are worked out on your machine, so it updates smoothly.
• Complete, global coverage — every catalogued object, everywhere, with none of the receiver-coverage gaps that thin out AIS or ADS-B over the oceans.

Features

• Pick a group — space stations (ISS, Tiangong), the brightest satellites, the GPS constellation, weather satellites, Starlink, or all ~11,000 active satellites.
• Area-based — watch everything over your map view or a drawn box.
• Coloured by constellation/type, with name, NORAD id, altitude and orbital speed. Zenith also derives the launch year (from the international designator) and the orbit class (LEO / MEO / GEO). Click a satellite to open it on N2YO.
• Cluster badges for busy regions; zoom in and they fan out.
• No extra dependencies — the SGP4 propagator (pure-Python sgp4, MIT) is vendored, and everything else uses QGIS's own stack, so it installs cleanly from the plugin repository.

Screenshots

Choose a group and see it coloured by type — here the weather satellites over the Arctic, with the category legend:

Identify any satellite for its full detail — including the derived orbit class and launch year (this one's a spent rocket body in low-Earth orbit):

Install

1. Download this repository as a ZIP (or clone it).
2. In QGIS: Plugins → Manage and Install Plugins → Install from ZIP, and select the zipped zenith/ folder, or copy zenith/ into your QGIS plugins directory.
3. Enable Zenith. A Zenith panel appears on the right.

Usage

1. Choose a Source (all keyless — no configuration).
2. Choose Track the current map view or Draw an area on the map.
3. Click Start tracking. Zenith fetches the orbital elements, then satellites stream onto the map and move in real time.

Notes

• Positions are computed from TLEs, which are accurate to roughly a kilometre and refresh slowly; Zenith caches them for a couple of hours to respect CelesTrak.
• "All active satellites" is the full catalogue — zoom into a region for the clearest view.
• The Brightest satellites group is a curated set of naked-eye objects (best seen at twilight); it is not a live "visible from where I am now" filter.

Credits

Orbit propagation uses the pure-Python sgp4 library by Brandon Rhodes (MIT), vendored under zenith/vendor/. Orbital elements from CelesTrak.

License

GPL-2.0-or-later.