【英语时差8,16】鞋子里的GPS（下）

But measuring movement is actually pretty tricky¹. Any small mistake in the measured acceleration² results in position errors that grow with time. So even if you’re standing³ still and just rocking in place, a navigation computer relying solely⁴ on the IMU readings may show you wandering off in a random⁵ direction. And that’s where radar⁶ comes in. Engineers have developed a tiny radar sensor⁷ and navigation computer that attach to a shoe to keep track of the space between the shoe’s heel and the ground. Basically, the radar system helps the IMU device more accurately⁸ sense when you’re moving and when you’ve stopped, which helps reduce navigation errors. None of this technology is available in your local shoe store yet. But someday it could find its way there.

1 tricky   

adj.狡猾的，奸诈的；(工作等)棘手的，微妙的

参考例句：

• I'm in a rather tricky position.Can you help me out?我的处境很棘手，你能帮我吗？
• He avoided this tricky question and talked in generalities.他回避了这个非常微妙的问题，只做了个笼统的表述。

2 acceleration   

n.加速，加速度

参考例句：

• All spacemen must be able to bear acceleration.所有太空人都应能承受加速度。
• He has also called for an acceleration of political reforms.他同时呼吁加快政治改革的步伐。

3 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

4 solely   

adv.仅仅，唯一地

参考例句：

• Success should not be measured solely by educational achievement.成功与否不应只用学业成绩来衡量。
• The town depends almost solely on the tourist trade.这座城市几乎完全靠旅游业维持。

5 random   

adj.随机的；任意的；n.偶然的(或随便的)行动

参考例句：

• The list is arranged in a random order.名单排列不分先后。
• On random inspection the meat was found to be bad.经抽查，发现肉变质了。

6 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。

7 sensor   

n.传感器，探测设备，感觉器（官）

参考例句：

• The temperature sensor is enclosed in a protective well.温度传感器密封在保护套管中。
• He plugged the sensor into a outlet.他把传感器插进电源插座。

8 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。