◆ Mission Control · Radio

Ham Radio via Satellite

Find amateur radio satellites, look up frequencies, plan your next contact

Cross-source satellite search · Frequency directory · Doppler planner · SGP4 pass prediction

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Grid square —
AMSAT data —
SatNOGS data —
— AMSAT satellites
— Active payloads
— FM
— APRS / Packet
— FSK / Telemetry
— Linear / SSB
— Beacon
— Stale TLEs Old orbital data

Ham Satellites

Search for a satellite by name or callsign Cross-source search: AMSAT · SatNOGS · Space-Track
◈ Satellite Search Name · Callsign · NORAD · COSPAR
Type 2+ characters to search — results link to the satellite profile page when orbital data is available
△ Visible Ham Satellites
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○ Sky View — Now Above Horizon updates every 30s
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ISS Radio

ARISS · 145.825 MHz · Digipeater
○ ISS Active Frequencies
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○ Full ISS Radio Panel

The ISS Tracker page has a complete radio section with live Doppler shift, APRS digipeater info, and a radio pass score for your next ISS pass.

Live Doppler shift (145.825 MHz), pass-quality radio score, active/inactive frequency table, SatNOGS telemetry decoder info, and NORAD 25544 / XSKZ-5603-1870-9019-3066.

Open ISS Tracker → Radio Section ↗
Doppler Planner — Coming in Phase 8
Select any active satellite and frequency; live Doppler offset calculated from your location using SGP4 range-rate.
△ ISS Pass Planner See ISS Tracker for full pass table
Radio-optimised pass planner
Pass score based on elevation and duration (not sky darkness). Shows Doppler-shifted frequency at AOS, peak, and LOS for each pass.

Beginner Guide

Getting started with ham radio via satellite
■ What are ham satellites?

Amateur radio satellites (“ham-sats”) are small spacecraft built by radio amateurs and universities. Most carry transponders or digipeaters that licensed ham operators can use for voice contacts, digital messaging, or APRS packet relay.

Common modes

FM voice
Simple FM radios work fine. Tune your transceiver, account for Doppler drift, and make contacts during the 5–12 minute overhead pass.
APRS / Digipeater
The ISS at 145.825 MHz is the most accessible. Any APRS-capable radio or app can send packets through it.
Linear transponder
Inverting SSB/CW transponders. More complex to operate — your uplink frequency adjusts as the satellite moves.
Telemetry & beacons
Many CubeSats transmit FSK, GMSK, or BPSK telemetry data. SDR receivers work well for these weak signals.
■ Equipment & what’s needed

Minimum for FM/APRS

  • A licensed amateur radio operator (Technician class in the US)
  • A handheld dual-band (144/430 MHz) transceiver
  • A directional antenna (yagi) or crossed dipole — for LEO passes, manually tracking improves signal
  • Satellite pass prediction — this page, or any TLE-based tool

Doppler shift

As the satellite approaches, received frequencies sound higher. As it recedes, they sound lower. At 145 MHz this shift is roughly ±3 kHz over a pass. Many modern radios have Doppler-tracking modes.

Grid squares (Maidenhead)

Ham operators exchange grid squares (e.g. EM28) during satellite contacts. Your grid square is shown at the top of this page.

Data Health

Source ingest status, coverage gaps, NORAD link quality How fresh is the satellite data?
◇ Ingest Status
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△ Sky Dome Coming in Phase 8
Polar sky dome view
All ham satellites with passes in the next 24 hours plotted on an azimuth/elevation dome view. Click any arc to see the satellite profile and active frequencies.