二维改进的分形模型在海面电磁散射中的应用  

Application of improved fractal model for electromagnetic scattering from sea surface

作　　者：陈瑜 胡云安[2] 林涛[2] 王宏伟[2] 

机构地区：[1]91213部队 [2]海军航空工程学院控制工程系

出　　处：《南京理工大学学报》2014年第1期140-146,共7页Journal of Nanjing University of Science and Technology

基　　金：军队科研基金资助项目

摘　　要：针对分形海面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分形模型相结合的二维海面模型,确定了方向海谱的闭式解。在满足基尔霍夫近似的条件下推导了改进海面模型的散射系数和散射强度系数的闭式解。从仿真结果可知:所得功率谱与PM谱和南海的实测数据都拟合的很好,验证了该模型的正确性,并且海面的分形特性也能在散射信号中得到很好的表现。Aiming at the problem that the ominidirectional sea-wave spectrum of fractal sea-wave model can not satisfy the positive power law when spatial wave numbers are smaller than the fundamental wave number,a 2-D sea surface model is proposed by combining statistical sea surface model and normalization band-limited Weierstrass-Mandelbrot（ WM） fractal sea surface model. With the proposed method,the closed form expression of the directional sea-wave spectrum is calculated. Scattering coefficients and scattering intensity coefficients of the improved sea surface model based on the Kirchhoff approximation are derived. Simulation results show that omnidirectional sea-wave spectrum is in good agreement with the common spectrum of Pierson-Moskowitz （ PM ） and the real data of the South China Sea. This proves the validity of the improved model, and the fractal characteristics of sea surface is also well represented in the scattering signal.

关 键 词：分形模型 Longuet-Higgin模型 电磁散射 Kirchhoff近似 

分 类 号：O451[理学—无线电物理]