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-Mandelbrot(WM)分形模型相结合的一维粗糙海面模型,确定了功率谱的闭式解,并且和Pierson-Moscowitz(PM)谱进行了比较,两者吻合较好。在双尺度法下推导了改进模型电磁散射系数的闭合解,对Longuet-Higgins模型、经典分形模型和改进模型的电磁散射系数的角分布进行了比较,发现3种模型散射系数之间的差距主要是由于大尺度波浪的不同造成的,证明了改进模型的有效性,并通过实测数据进行了验证。
Aiming at the problem that the omnidirectional sea-wave spectrum of fractal sea-wave model cannot satisfy the positive power law when the spatial wave number is smaller than the fundamental wave number, one-dimensional （1D） sea-wave model is proposed by combining statistical sea model and normalized band-limited Weierstrass- Mandelbrot （WM） fractal sea model. With the proposed method, the closed form expression of the omnidirectional sea-wave spectrum is calculated, and the obtained omnidirectional sea-wave spectrum is in good agreement with the commonly used Pierson-Moscowitz （PM） spectrum. The electromagnetic scattering coefficient of the improved model based on two-scale method is derived. The angular distributions of the scattering coefficient of Longuet-Higgins model, classical fractal model and improved model are analyzed. Simulation shows that the difference among the three model＇s scattering coefficients is caused by the large scale of sea-wave, which proves the validity of the model. The results are also validated by real data.
出处
《激光与光电子学进展》
CSCD
北大核心
2012年第12期29-34,共6页
Laser & Optoelectronics Progress
基金
军队科研基金(61004002)资助课题
