Get speed and ground track (or heading) from the velocity message
    (handles both airborne or surface message)

    Args:
        msg (string): 28 bytes hexadecimal message string

    Returns:
        (int, float): speed (kt), ground track or heading (degree)

def speed_heading(msg):
    """Get speed and ground track (or heading) from the velocity message
    (handles both airborne or surface message)

    Args:
        msg (string): 28 bytes hexadecimal message string

    Returns:
        (int, float): speed (kt), ground track or heading (degree)
    """
    spd, trk_or_hdg, rocd, tag = velocity(msg)
    return spd, trk_or_hdg