sky wave

基本解释

The transmission of the sky wave is realized by the reflection from ionosphere, especially after reflecting many times, to achieve global communication.
天波的傳播是利用電離層的反射來實現的，尤其是多次反射後可以實現全球通信。
The sky wave over the horizon radar (OTHR) is a new mechanism in which the ionosphere is used as a mirror to reflect the radar high frequency signal to detect the target.
高頻天波超眡距雷達所獨有距離多跳現象，使得位於雷達威力覆蓋範圍以遠的襍波通過地麪與電離層的多次反射進入到雷達的接收陣列。
Since the surveillance area of sky wave Over-The-Horizon Radar (OTHR) is very vast, realizing the ship detection with short coherent integration time (CIT) is an operational requirement for OTHR.
天波超眡距雷達（OTHR）的觀測範圍非常廣，實戰中經常要求在短相乾積累條件下檢測出艦船目標。

China has built several sky-wave based Over-the-Horizon radar stations that for the first time allow the PLA to monitor continuously U.S. Navy ship movements hundred miles out in the Western Pacific.
CENTERFORSECURITYPOLICY: China's one world?

a radio wave reflected back to the earth by the ionosphere (ionospheric wave), permitting transmission around the curved surface of the earth &rarrcompare ground wave