Numerical simulation of the EM scattering and Doppler spectrum of a low flying target above dynamic oceanic surface by using the FEMDDM method  

作　　者：LIU Peng JIN Yaqiu 

机构地区：[1]Key Laboratory of Wave Scattering and Remote Sensing Information Ministry of Education, Fudan University, Shanghai 200433, China Key Laboratory of Wave Scattering and Remote Sensing Information Ministry of Education, Fudan University, Shanghai 200433, China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2004年第5期597-611,共15页中国科学：物理学、力学、天文学（英文版）

基　　金：This work was supported by the China State Key Basic Research Project(Grant No.2001CB309401-05);the National Natural Science Foundation of China(Grant No.60170009).

摘　　要：To study the Doppler (DP) spectrum of a flying target above the dynamic oceanic surface, a two-level quasi-stationary algorithm (TLQSA) of the finite element method (FEM) with domain decomposition (DDM) is developed. The DP spectrum of a fast-moving target requires a small time-sampling rate. At most time steps, scattering from the flying target is solved by the FEM solution in only one sub-domain; meanwhile the interactions between the target and rough sea surface in other sub-domains are obtained by solving the global DDM coupling matrices. The slowly moving sea surface is evolved at a larger time step and the DP of oceanic clutter is obtained through all-subdomain FEM calculation. Numerical simulations of the DP spectrum from a target flying above the dynamic oceanic surface with and without a ship presence are obtained. The functional dependence of the DP spectrum in both the time and frequency domains upon the sea surface wind speed, target altitude, observation angle etc. are demon- strated and discussed.To study the Doppler (DP) spectrum of a flying target above the dynamic oceanic surface, a two-level quasi-stationary algorithm (TLQSA) of the finite element method (FEM) with domain decomposition (DDM) is developed. The DP spectrum of a fast-moving target requires a small time-sampling rate. At most time steps, scattering from the flying target is solved by the FEM solution in only one sub-domain; meanwhile the interactions between the target and rough sea surface in other sub-domains are obtained by solving the global DDM coupling matrices. The slowly moving sea surface is evolved at a larger time step and the DP of oceanic clutter is obtained through all-subdomain FEM calculation. Numerical simulations of the DP spectrum from a target flying above the dynamic oceanic surface with and without a ship presence are obtained. The functional dependence of the DP spectrum in both the time and frequency domains upon the sea surface wind speed, target altitude, observation angle etc. are demonstrated and discussed.

关 键 词：DOPPLER spectrum  ROUGH SURFACE and target  electromagnetic scattering  domain decomposition method  finite element method. 

分 类 号：N[自然科学总论]