OnAirDecode ASTERIX with an SDR
ASTERIX: radar and ADS-B surveillance data from UDP or a file.
- Group
- Aviation
- In the mode list
- CAT 021, 048, 062 over UDP or from a file
What ASTERIX is
ASTERIX surveillance data from a network or a file (no radio): CAT 021 ADS-B target reports, CAT 048 monoradar target reports and CAT 062 system tracks as UDP datagrams (unicast or multicast) or a recording (raw blocks or a pcap capture), shown as a track table and a map. A radar's own pulses cannot be received by a software radio; this reads the data a radar or ground station sends. Receive….
Frequencies and settings
OnAir takes any frequency you type; the numbers above are the mode's starting point and the range its table describes. In the app the shortcut label is CAT 021, 048, 062 over UDP or from a file.
What OnAir shows
ASTERIX surveillance data from a network or a file (no radio): CAT 021 ADS-B target reports, CAT 048 monoradar target reports and CAT 062 system tracks as UDP datagrams (unicast or multicast) or a recording (raw blocks or a pcap capture), shown as a track table and a map. A radar's own pulses cannot be received by a software radio; this reads the data a radar or ground station sends. Receive only, the port is closed until you start listening.
Limits and what it was checked with
Checked with generated signals and impairments; recordings of real signals welcome.
Which radio you need
Any radio that tunes this range works. An RTL-SDR covers roughly 24 MHz to 1.7 GHz, and every other radio in the radio guide reaches it too. Antenna height and a clear view of the transmitter matter most.
Receiving and the law
Questions about ASTERIX
Can I decode ASTERIX with an RTL-SDR?
Usually yes for narrowband signals, as an RTL-SDR tunes roughly 24 MHz to 1.7 GHz at up to about 2.4 Msps. Wide signals such as TV channels need a faster radio, and OnAir says next to the source what the selected radio can do.
Is it legal to receive ASTERIX?
Receiving aircraft broadcasts is legal in many countries, but some restrict listening to or using what you hear. OnAir is a receiver. Check the rules where you live.
Can I try ASTERIX in OnAir without a radio?
Yes. Most modes include a built-in synthetic test signal, so you can open the screen and try the controls before you own a radio.