天波超视距雷达缺损信号的频谱重构

Optimal reconstruction of spectrum with partial samples in OTHR

天波超视距雷达(over-the-horizon radar,OTHR)电波通过电离层折射作下视探测,具有观察距离远、观察范围广、反隐身等特点。但由于OTHR通常采用HF频段,电波传播环境复杂,回波存在很强的瞬态干扰。对OTHR信号的瞬态干扰抑制导致信号缺损。同时,现代OTHR需要多目标海空兼容工作,也导致回波信号的非均匀连续采样。针对OTHR信号的部分缺损问题,提出了基于稀疏信号处理的完整频谱重建算法。算法中将OTHR稀缺信号的频谱重建问题转化为一个范数1优化函数的求解问题,直接获得信号的完整频谱。利用仿真和实测数据分别对干扰和非连续采样导致的缺损信号进行频谱恢复,结果验证了算法的有效性。

Over-the-horizon radar（OTHR） looks down its targets from the ionosphere.Compared with conventional radar systems,it has superiorities,such as large observing range,wide cover areas,anti-concealed capability.But signal echoes are usually contaminated by transient interference.To filter out the interference is available while it destroys the integrity of signals in time domain.What is more,a modern OTHR system is usually required to be multi-mode and is able to detect multi-target simultaneously under different backgrounds.To satisfy these requirements,an incontinuous sampling mode is usually applied resulting in parts of signal missing.A novel algorithm is proposed to reconstruct the full spectrum of OTHR with partial clear signals.The spectrum reconstruction problem is shifted into a problem of a norm l constrained optimal problem.By solving this problem with a greedy algorithm efficiently,the integrate frequency spectrum of OTHR signals is reconstructed optimally.Both simulated and real measured data are used to validate the proposal.