So if we take some outbound path -- perhaps we park and we wander off -- we know because our own movements, which we can integrate over this path roughly what the heading direction is to go back.
因此当我们外出时—— 或许是我们停车后下来随便走走—— 我们可以给自己定位，因为我们 可以粗略地将自己的运动路线 与大体的返回方向进行整合。