天波雷达电离层信道建模

Sky-wave OTHR ionospheric channel modeling

以三维射线追踪和相位屏/衍射方法为基础,建立了天波雷达电离层信道模型.首先,将国际参考电离层模型和国际地磁参考场模型集成到三维射线追踪计算中.为满足天波雷达双程信道建模的需要,提出了一种新的收发射线匹配算法.利用相位屏/衍射方法直接计算信道双频、双点、双时相关函数,得到了强闪烁下的随机信道冲击响应函数,对其进行修正,使其也适用于弱闪烁情形.最后,对匹配的收发射线对应冲击响应函数进行二维卷积,并计入信道损耗,得到天波雷达双程信道模型.该信道模型可用于天波超视距雷达信号建模和后续信号处理的研究.

A new model for sky-wave over the horizon radar（OHTR） ionospheric channels based on ray tracing and phase screen/diffraction method is developed. The international reference ionosphere model and the international geomagnetic refer- ence field（IGRF）model are integrated with a classical 3D ray tracing code A new al- gorithm for matching of outbound and return ray paths is developed to meet the need of sky wave two-way channel modeling. The two-frequency, two-position, two- time mutual coherence function of ionospheric channel is calculated directly by phase screen/diffraction method, from which a stochastic pulse response function for strong scintillations is obtained. Then the stochastic pulse response function is modified to be suitable for weak scintillations. After that,the sky-wave OTHR two way channel model is calculated by convoluting the pulse response function corre- sponding to matched outbound and return ray paths in two domains, and including the channel loss. This channel model can be used for sky-wave OTHR signal model- ing and signal processing studies.