Abstract:

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. Now OTHR has drawn attention of many countries due to its outstanding advantages, such as the capabilities of wide area surveillance, anti low flying aircraft, anti stealth,early warning, etc . In this paper, the characteristics and development history of OTHR are introduced firstly. Then the radar architecture follows. After that, the techniques on interference suppression, correction of ionospheric contamination, and target detection are reviewed in detail. At the end of this paper, the ways ahead in this field are also pointed out.

Key words: sky wave over-the-horizon radar, clutter, interference, ionospheric phase variation, target detection