darkmap

An ad-free dark-sky and atmosphere planning map for the work that happens above the horizon — astronomy, air quality, atmospheric optics, and satellite passes. Live at https://darkmap.phasi.space.

darkmap re-presents open public datasets on one shared map, re-weighted for four kinds of user — and it never hides a feature behind a mode you have to discover.

One map, four lenses

Pick a lens and the same map re-orders and re-emphasizes itself for your work; nothing is greyed out or removed.

• ◐ Sky — dark-sky & astrophotography planning: Bortle/SQM from VIIRS + Falchi 2016, sun/moon ephemeris, and tonight's dark window.
• ☁ Air — air quality & atmosphere: multi-pollutant NowCast AQI, an OpenAQ ground-station layer, and cloud / aerosol / water-vapor overlays.
• 📡 Links — RF / laser link planning: atmospheric transmission T(λ) computed along the actual beam, with a go / no-go link-budget margin.
• 🛰 Orbit — LEO ground-station ops: satellite passes gated by the real terrain horizon (not a flat one), with az/el track, Doppler, and keyhole notes.

Every derived value carries an honesty label — measured / modeled / predicted — and its coverage caveats; the map never fabricates a reading it doesn't have.

Built on open data and prior art

darkmap stands on the shoulders of open datasets and earlier work. The idea was inspired by lightpollutionmap.info — an inspiration and comparison point, not an affiliation or primary attribution.

• Light pollution — NASA/NOAA VIIRS Day/Night Band + Falchi et al. 2016, The new world atlas of artificial night sky brightness
• Atmosphere — NASA GIBS (clouds, aerosol optical depth, water vapor) + Open-Meteo point forecast & CAMS air quality (CC-BY 4.0)
• Ground air quality — OpenAQ v3 (CC-BY 4.0)
• Orbital elements — Celestrak TLEs (SGP4 via satellite.js)
• Spectral bands — a curated HITRAN2020 line subset
• Geocoding & elevation — OpenStreetMap via Photon + AWS Terrarium terrain tiles

See /docs for the full, canonical attribution.

Run it

The Justfile is the authoritative entrypoint for every local and CI command.

direnv allow
just setup     # pnpm install
just check     # lint + typecheck + unit tests
just build
just dev

Stack

SvelteKit (adapter-node) · Svelte 5 + TypeScript · MapLibre GL · Skeleton 4.15.2 (pinned) + Tailwind v4 · Effect.ts service layers · astronomy-engine + satellite.js. Just + Nix for local dev; Bazel/Bzlmod for the module graph and unit-test proofs.

Privacy

• No user accounts, payments, runtime database, or write APIs.
• No analytics or ad-tech.
• Upstream data APIs are proxied only to normalize responses and add caching; the one runtime secret (an OpenAQ key) lives outside the repo, never in git.

Contributing

Issues and PRs are welcome — there are a few good first issues to start with (a logo, contributor docs, a perf pass). Agents and operators should read AGENTS.md first.