And carrying GPS receivers to reveal their secret journeys.

并戴着 GPS 接收器揭示他们的秘密旅程。

When one reaches a GPS receiver, it compares its local time to the time that message was sent.

当某条信息到达 GPS 接收器时，它会比较本地时间与消息发送的时间。

GPS relies on real-time satellite data that streams down to GPS receivers.

GPS 依赖于传输至 GPS 接收器的实时卫星数据。