145.800 · satellites
The Space Station and various amateur radio satellites cross the skies of all Brazil every day, and you can hear many of them with a handheld radio. Choose your city and see the upcoming passes, where each one enters and exits, and what frequency to listen on.
48 hours, Brasilia time.
Lendo os elementos orbitais...
Tap a band to see the pass in the sky and Doppler. Using the keyboard, Tab reaches each band and Enter selects.
Chosen pass
The center is well above your head; the edge is the horizon. North at the top.
Position every 5 seconds, orbit trail, and footprint: from within it the satellite is above the horizon.
The dark area is the side of the Earth where it is already night. The ISS is only visible to the naked eye when you are in the dark and it is still in the sun, near dusk or dawn.
FM
They work like a hilltop repeater, except at an altitude of 500 km. Someone talks on the uplink, the satellite repeats on the downlink, and you hear the conversation in standard FM. They are fast: a pass lasts about 10 minutes and contacts are brief, exchanging callsign and grid.
Linear
Instead of a single channel, they repeat an entire 50 to 100 kHz slice. Several conversations fit at the same time, in SSB and CW, each at a point in the band. To listen you need a receiver with SSB, like an SDR, and to track the Doppler with the tuning knob.
APRS and digital
Short bursts of data: position and messages from ground stations repeated by the satellite (APRS), or the satellite's own telemetry, with battery voltage and temperature. From the speaker it sounds like modem static, a decoder program turns it into text.
Anyone can listen to amateur radio satellites, record, and show what they heard: that is what they are for. Uplink frequencies are shown here for information only. Transmitting to a satellite requires an Anatel amateur radio license in the class that permits the used band.
If you want to talk through a satellite one day, the path starts with the Anatel exam. How to become an amateur radio operator.
Orbital elements are from CelesTrak, updated by the laboratory a few times a day. Passes, position, and Doppler are calculated in your browser using the SGP4 model. Frequencies and the status of each satellite were manually verified against public AMSAT and ARISS tables, and any satellite in doubt was left out. Status changes: before building an antenna, check the AMSAT dashboard.
Data: elementos.json. Sources: CelesTrak orbital elements (celestrak.org, Dr. T.S. Kelso), derived from the public catalog of the 18th Space Defense Squadron; frequencies and status checked on AMSAT and in the ARISS. Orbit calculation with satellite.js (MIT license). No affiliation or endorsement from either.