Originally Posted by
clearedtocross
Short messages mean data condensed to the minimum. Thus e.g a timestamp in not included as it is meaningless in real time navigation. Anything else than 3d-position, 3d-vector and aircraft id is not repeated in the standard broadcast.
Good summary of ADS-B. But just to clarify "3d-position, 3d-vector and aircraft ID" are all sent in separate broadcasts as they can't all be accommodated in a single 56-bit packet.
That's one of the reasons, of course, why FR24 data has to be treated with caution as it populates data items that aren't in any given packet with stale values from a previous transmission.