| 摘要: |
| 针对经典分形模型的功率谱在空间波数小于基波波数时不能满足正幂率的问题，提出
了一种统计模型和归一化带限Weierstrass分形模型相结合的一维粗糙海面模型，得到改进
分形表面功率谱，并且和PM谱进行了对比，对分形维数、频率幅度尺度因子、风速等参量对
一维海面轮廓的影响做了进一步分析。研究表明：在不同风速下表面功率谱和PM变化趋势是
一致的，证明了改进方法的正确性。海面形状具有大尺度涌浪和小尺度张力波的特性，并且
统计模型和分形模型的性质在改进模型中依然适用，验证了模型的合理性。 |
| 关键词: 海面电磁散射 分形模型 海谱 Longuet-Higgin模型 P-M谱 |
| DOI： |
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| 基金项目: |
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| A one-dimensional improved fractal model of sea surface and sea spectrum evaluation |
| CHEN Yu,HU Yun-an,ZHANG Gang,ZHANG Jing-ming |
| (Department of Control Engineering,Naval Aeronautic Engineering Institute,Yantai 264001,China;Common Subjects Teaching and Research Room,Unit 92060 of PLA, Dalian 116000,China) |
| Abstract: |
| As to the problem that the fractal spectrum can not satisfy the positive
power law when wave numbers are smaller than the fundamental wave number, an im
prove
d 1D fractal model is proposed. This proposed model is a combination of statist
ical sea model and normalization band-limited Weierstrass-Mandelbrot(WM) fract
al sea model. The improved fractal sea wave spectrum is derived, and th
e results are compared with the PM sea wave spectrum.A further study on improved
fr
actal model′s fractal dimension, the frequency and amplitude factor and wind sp
eed affecting the sea-surface is made. The analysis illustrates that improved fr
actal sea wave
spectrum shows good agreements with PM spectrum′s change trend for different w
i
nd speed, which proves the correctness of the improved method. Sea surface has c
harac
ters of large-scale turbulent waves and micro-scale capillary wave, while statis
tical model and fractal model′s characters can be still applied in improved fra
ctal model. The rationality of improved fractal model is validated. |
| Key words: sea surface EM scattering fractal model sea wave spectrum Longuet-Higgin model P-M spectrum |
