高频地波雷达多干扰的极化抑制

天波电台干扰是高频地波雷达所面临的主要干扰,虽然采用频率捷变技术可以躲避干扰,但是当短波电台十分密集时很难找到合适工作频段的,而且当存在与雷达回波同方向入射的干扰时,空间滤波技术也无能为力。利用极化技术可以较好地解决以下问题,但目前高频地波雷达中的极化滤波还只限于对单干扰的抑制,为了进一步拓宽雷达的工作频段,本文研究了多干扰的极化抑制问题,给出了一种在频域同时提取多干扰极化特征的方法,并根据这一方法构造了一种频域极化滤波器,使得频带互不重叠的多个干扰可以被有效滤除,而不受极化度的限制,从而克服了以往极化滤波器只能处理极化度较高的干扰的特点。理论和仿真实验证明了算法的有效性。

Polarization Suppression of Multidisturbance in HF Ground Wave Radar

Sky-wave disturbances are the main interference to HF ground wave radar. Though frequency agility is used to evade the interference, it is not effective when radio disturbances are too much congested. When the incident disturbance and the backscattering radar signal have same incoming direction, space-filtering technique is not effective too. Polarization technique can be used to solve these problems. But the studies of polarization filter in HF ground wave radar are only limited to the field of single disturbance suppression up to now. In order to expand radar?s working frequency band, multidisturbance suppressing is studied with a new polarization 131ter called frequency spectrum polarization filter, which is based on a new polarization extracting technique. With this techque, the polarizations of different disturbances with their frequency bands not overlapping can be extracted simultaneously in frequency band and all the disturbances can be effectively suppressed regardless of the polarization degree of their mixed signal. This gets rid of the restriction that common polarization filter can only cope with single disturbance with high polarization degree. Effectiveness of the algorithm has been proved by theory and simulation experiment.