Decodes a Mode A/C reply, as carried by a Beast type-1 frame. Beast
represents the reply as the raw big-endian 16-bit value dump1090-fa
calls "ModeA" internally: each of the four squawk digits occupies one
nibble (masking with 0x7777 isolates them), with the Ident pulse and a
couple of spare bits interspersed.
Mode A/C carries no ICAO address, so a decoded reply cannot be
associated with a specific aircraft the way a Mode-S message can - it is
decode-only in this package, not wired into any aircraft-tracking state.
Parameters
bytes: Uint8Array
The 2-byte Mode A/C payload from a Beast type-1 frame.
Decodes a Mode A/C reply, as carried by a Beast type-1 frame. Beast represents the reply as the raw big-endian 16-bit value dump1090-fa calls "ModeA" internally: each of the four squawk digits occupies one nibble (masking with
0x7777isolates them), with the Ident pulse and a couple of spare bits interspersed.Mode A/C carries no ICAO address, so a decoded reply cannot be associated with a specific aircraft the way a Mode-S message can - it is decode-only in this package, not wired into any aircraft-tracking state.