def get_sounding_direction(bufr_msg):
    """
    Get direction of sounding

    1: upward
    -1: downward
    """
    if str(bufr_msg) == '309052':
        return 1
    elif str(bufr_msg) == '309053':
        return -1
    elif str(bufr_msg) == '309056':
        return -1
    elif str(bufr_msg) == '309057':
        return 1
    else:
        raise NotImplementedError(
            'The bufr message format {} is not implemented'.format(bufr_msg))
