摘要
因受电离层调制影响,传统的高频海杂波模型难以全面描述天波超视距雷达海杂波的空域非均匀性和时域非平稳性。该文首先基于传统的Walsh高频海杂波模型分析了洋流的影响,提出电离层子反射面模型的概念,揭示了相干处理间隔内电离层对高频信号频谱的调制机理;然后通过建立电离层等效反射面,并将其分解为多个子反射面的方式,给出可以综合反映不同海态、不同电离层状态的天波超视距雷达海杂波修正模型。最后结合数学描述,利用该文修正模型反演分析了由电离层的空域非均匀、时域非平稳引起的典型高频海杂波多普勒偏移、展宽、分裂和多径复杂现象的实测数据多普勒谱,仿真与实测数据多普勒谱验证了所提修正模型的准确性与鲁棒性。
As modulated by the ionosphere, the classical High-Frequency （HF） model of ocean clutter can not describe the HF scatterings from sea surface approvingly in view of skywave Over-The-Horizon Radar （OTHR）. In this paper, ocean current is taken into consideration based on the Walsh HF sea clutter model. An equivalent ionospheric reflecting screen model is established which can be resolved into several sub screens, based on which the ionospheric modulation on frequency is discussed. Incorporating with Walsh model, a normalized sea clutter model for skywave OTHR is presented. Using the presented model, the spectrums in different cases involving Doppler shift, spectrum broadening, splitting and multipath propagation are simulated, and comparing with the measured data, the model＇s validity and robustness are verified.
出处
《电子与信息学报》
EI
CSCD
北大核心
2017年第12期2881-2888,共8页
Journal of Electronics & Information Technology
基金
国家自然科学基金(61471391
61072132)~~
关键词
天波超视距雷达
海杂波模型
电离层子反射面模型:电离层等效反射面
Skywave Over-The-Horizon Radar （OTHR）
Sea clutter model
Ionospheric sub reflecting screen
Equivalent ionospheric reflecting screen
