Their movement can be followed with the help of Global Positioning System (GPS) equipment.

他们的运动轨迹可以在全球定位系统的帮助下进行追踪。

They say the government's Global Positioning System (GPS) also transmits time signals.

他们说政府的全球定位系统 (GPS) 也传送时间信号。

Using the Global Positioning System (gps) to track them—a first—he found that they knew exactly where the boundaries of protected areas were.

他第一次使用全球定位系统 (gps) 跟踪它们，发现它们确切地知道保护区的边界在哪里。