PhosphorBeam

PhosphorBeam is a real-time amateur radio satellite tracker built for operators who work the birds. Track passes, compute Doppler corrections, and plan contacts — all through a retro phosphor terminal interface.

REAL-TIME 3D GLOBE
A rotating 3D globe displays your favourited satellites with radio footprint coverage circles. Drag to rotate, pinch to zoom, double-tap to snap back to your ground station. Fly to any tracked satellite with the GOTO control. Geostationary birds like QO-100 are shown with distinct footprints.

PASS PREDICTION
Accurate SGP4 orbital propagation predicts upcoming passes for all your favourited satellites. Configure the prediction window (12, 24, or 48 hours), set minimum elevation thresholds, and optionally include NOAA APT weather satellites. Each pass shows AOS/LOS times, maximum elevation, azimuth sweep, duration, and a quality rating so you can prioritise the best contacts.

DOPPLER CORRECTION
Tap any predicted pass for a detailed view with sky track polar plot and Doppler frequency curves. Separate RX and TX plots are auto-scaled to show the kHz shift clearly. The AOS-to-LOS corrected frequency range is displayed above each plot so you know exactly where to tune before the satellite rises. During active passes, real-time corrected frequencies, range, azimuth, and elevation update every second.

COMPREHENSIVE SATELLITE DATABASE
Ships with a curated database of popular amateur satellites including FM repeaters (SO-50, ISS, TEVEL constellation), linear transponders (RS-44, AO-73, FO-29, AO-7), digital repeaters, and geostationary transponders. The database automatically expands by fetching active transponder data from AMSAT and orbital elements from CelesTrak. Browse, search, and filter by transponder type — FM, SSB, digital, or receive-only.

DETAILED ORBITAL DATA
Every satellite with orbital elements displays comprehensive information: altitude, orbital velocity, apogee, perigee, inclination, period, passes per day, revolution count, eccentricity, BSTAR drag coefficient, and TLE epoch. International designator and NORAD catalogue number identify each bird.

OFFLINE FIRST
Bundled orbital elements for key satellites mean the globe and pass predictions work immediately on first launch, even without network connectivity. Once online, TLEs refresh automatically from CelesTrak every 12 hours and transponder data from AMSAT every 24