Overhead

Live ISS tracker + visible-pass predictions for a fixed observer (default: Tulsa, OK). Public at https://bunko.me/overhead.

• Live position — the browser propagates the ISS from a Celestrak TLE with satellite.js for smooth per-frame motion.
• Visible passes — the backend computes upcoming passes with skyfield, counting a pass as visible only when the ISS is sunlit and the observer is in darkness.
• Look — "Apollo mission control": back-lit plot-board map, glowing ground track, day/night terminator, footprint circle, and a segmented AOS/LOS countdown.

Stack

FastAPI + skyfield (server) · vanilla JS + satellite.js (client) · Docker, behind the shared Caddy proxy on the web network. The DE421 ephemeris is baked into the image at build time so pass/visibility math works offline.

Config (environment)

var	default	meaning
BASE_PATH	/overhead	URL prefix the proxy strips
OBSERVER_LAT / OBSERVER_LON	36.1540 / -95.9928	observer location
OBSERVER_ELEV_M	210	observer elevation (m)
OBSERVER_NAME	Tulsa, OK	label shown in the UI
NORAD_ID	25544	satellite to track (default: ISS)

Endpoints

• GET / — the tracker page
• GET /api/tle — current cached TLE (for client-side propagation)
• GET /api/position — current sub-point, altitude, velocity, sunlit flag
• GET /api/passes — next visible passes for the observer
• GET /health

Develop

docker compose up -d --build