高频地波雷达电离层距离方程建模及仿真

Modeling and simulation of ionospheric range equation for high frequency surface radar

针对电离层的空间分布特征,构建了体目标和面目标的雷达距离方程.根据不规则体对高频电波的相干散射原理,估算了电离层RCS的散射系数,进而给出基于电离层物理机制的广义高频地波雷达方程,从而量化了电离层特征参数对高频雷达系统的影响.通过仿真发现,对于面散射情形,斜向散射电离层杂波符合波束限制模型,垂直向的电离层杂波符合脉冲限制模型;对于体散射,影响电离层杂波强度最主要的因素是不规则体波动幅度.

The distributed radar range equations of volume target and surface target are established,according to the unique distribution characteristics of ionosphere,and the scattering coefficient of the ionospheric RCS is estimated based on the principle of high frequency coherent scattering for irregularities.Thus,the generalized radar formula based on the physical mechanism of the ionosphere is derived,quantizing the impact of ionospheric characteristic parameters on HF radar system.Simulation results show that the near-vertical ionospheric echo conforms to the pulse-limited model,and the oblique ionospheric echo conforms to the beam-limited model,for the case of surface scattering with wide beam in HF surface wave radar.For volume scattering,the most important factor affecting the ionospheric clutter intensity is the amplitude of irregularities fluctuation.