A decoded Mode-S message. Discriminated by kind. DF24 (Comm-D) is
recognized at the envelope level but not decoded by this package -
decodeModeSMessage returns undefined for it, the same as a
genuinely unsupported or invalid message. DF19 (military extended
squitter) and DF22 (military use) are reserved formats with no publicly
documented payload and are not decoded, for the same reason.
A decoded Mode-S message. Discriminated by
kind. DF24 (Comm-D) is recognized at the envelope level but not decoded by this package - decodeModeSMessage returns undefined for it, the same as a genuinely unsupported or invalid message. DF19 (military extended squitter) and DF22 (military use) are reserved formats with no publicly documented payload and are not decoded, for the same reason.