How Do GPS Satellites Know Where You Are?
GPS卫星如何知道你的位置？
课文音频
Listen to the full story · 完整逐句/整段音频可在解锁后使用。
您仍可先看下方课文摘要；在阅读器可查看该书试读与权益说明。
课文
从第 4 课起，导读页仅展示部分正文，便于您了解难度与风格。
-
The Global Positioning System uses at least 24 satellites orbiting Earth at about 20,200 km, each broadcasting precise time signals.
-
Your phone or GPS device calculates its distance from each satellite by measuring how long the signal takes to arrive.
Unlock full vocabulary & bilingual guide · 完整课文、逐句音频与全部译文请在解锁学习权益后于阅读器中查看。
Improve faster解锁本课完整体验