A browser-based tool built by developer Armaan tracks every satellite that passed over your location in the last seven days and automatically pulls down any imagery those satellites captured of Earth. The project, hosted at watched.earth, runs entirely client-side using the SGP4 simplified perturbations model, meaning no data leaves your machine.
The architecture is worth examining. All orbital calculations happen locally in the browser. Self-hosting requires only a Vercel fork. The full source is on GitHub for anyone who wants to skip Vercel entirely. The automatic imagery download is the standout feature: you get the satellite pass data and the actual downlinked frames, no dish required.
The use cases extend beyond curiosity. Radio operators can use it to time contacts with satellite repeaters. ISS observers get a lightweight alternative to heavier tracking suites. Astronomers dealing with light pollution from megaconstellations now have a simple audit log of what crossed their field of view. Read the original for the self-hosting walkthrough and links to the SGP4 model documentation.
[READ ORIGINAL →]