经济学人下载:高科技橄榄球(2)

The sensors are attached to transmitters that communicate with receivers at the edges of the playing field.
传感器安装在发射器上，发射器与赛场边缘的接收器进行通信。

By monitoring the time it takes for signals to arrive at different receivers, and applying a little mathematics,
通过检测信号到达不同接收器所需的时间，再应用一些数学知识，

it is possible to work out where a player is on the pitch at any given moment, and how quickly he got there.
我们可以知道在某个特定时刻，一名运动员所处的位子以及他移动到这里的速度。

Such data, says Mr Macdonald, are attractive to teams looking for an edge over the competition.
Macdonald表示，对于那些希望在竞争中寻找优势的团队来说，这些数据颇具吸引力。

Previous efforts have relied on the Global Positioning System of satellites, which offers much lower accuracy.
之前的努力依靠的是全球卫星定位系统，其精度要低得多。

The firm has tested its technology with several professional clubs, including Saracens, the reigning champions in the English Premiership.
该公司已经与几家专业俱乐部进行了技术测试，其中包括英格兰超级联赛的卫冕冠军，萨拉森人。

Where the fun starts, though, is when similar sensors are put into the ball.
有趣的是，类似的传感器也会被放进橄榄球里。

It can then, metaphorically, squawk if passed forward (which is illegal in rugby),
打个比方，如果球向前传（这在橄榄球比赛中是违法的），它就会发出响而粗的叫声

and there will be no doubt, by comparing the positions of ball and player, when a player is offside.
毫无疑问，当一个球员越位时，通过比较球员和球的位置可以看出。

A smart ball will be able to monitor other rules, too.
一只聪明的橄榄球也能监控其他规则。

It was, for instance, tested successfully in a five-a-side version of the game called Rugby X,
例如，在一场被称为Rugby X的五人版比赛中，曾对它进行过一次成功的测试，

in which you are not allowed to kick the ball higher than ten metres.
在该场比赛中，是不允许把球踢到10米以上的。

Since few referees are equipped with theodolites, enforcing this rule has been hard. Now it is easy.
由于很少有裁判配备了经纬仪，因此执行这一规则很困难。现在就很简单了。