Understanding time_velocity, time_position

Which properties belong to time_velocity and time_position, respectively? It is obvious for latitude, longitude and velocity. But how about altitude, on_ground, heading, vertical_rate? What are the criteria for showing on_ground? Rarely, I've seen positions being set as on_ground but with high velocity and high altitude.

time_position: latitude, longitude, altitude, on_ground
time_velocity: velocity, heading, vertical_rate, on_ground

So the case you've observed was probably deprecated velocity information while on_ground was set by the last position update.

Considering this, I don't see any aircraft on ground with speed larger than takeoff or landing speed. Thank you.