At present greco is regarded as one of the most valuable methods of radar cross section ( rcs ) computation in the high - frequency region . depending on these conditions , several researches have been completed in this paper : firstly , calculating rcs of complex conducting targets has been accomplished by greco method . the high - frequency rcs of targets are obtained through physical optics ( po ) and incremental length diffraction coefficients ( ildc ) respectively 本论文做了以下研究工作：首先，实现了运用greco方法计算了高频区理想导体复杂目标的雷达散射截面( rcs ) ，分别应用了物理光学法( po )和增量长度绕射系数法( ildc )计算了目标的面元和棱边的电磁散射，最后综合面元与棱边的散射效应得到目标的总rcs 。
In addition combining opengl technology , we can translate the source shape data of targets displayed on the computer screen to the data for rcs computing . " graphical electromagnetic computing ( greco ) " was presented in these conditions , which has many merits such as detecting shadowed regions automatically , computing in real time and accurately and so on 图形电磁计算( graphicalelectromagneticcomputing ， greco )方法就是在这样的环境下产生的，它具有诸如自动实现消隐，计算速度快，精度高等优点，目前被认为是求解高频区复杂目标的最有效的方法之一。
On the aspect of the design of the rcs integrative software , the following had been completed : based the technology of the opengl , it completed a interface program with the display , modification and transform of the models ; it gave the concept of the shelter of the complex target and completed module that can handle the shelter of the target modeled with nurbs surface ; it completed the computation module include stationary phase method and gauss method based the research of the rcs computation method 在软件设计方面做了以下研究：在opengl的基础上完成了对nurbs模型能够进行显示、修改、变换的界面程序；给出了复杂目标的遮挡处理概念，并完成了能处理nurbs模型遮挡的模块；在算法的基础上完成了包括驻相法和gauss积分法的计算模块。
Research on electromagnetic scattering of complex targets has been received much attention for a long time , the fast inhomogeneous plane wave algorithm ( fipwa ) in this paper performs well in this purpose , and the computation complexity of its multilevel version ( mlfipwa ) is of the same order as the multilevel fast multipole algorithm ( mlfma ) 复杂目标电磁散射研究长期以来广受关注,本文研究的快速非均匀平面波算法,可以快速精确的求解任意复杂目标的电磁散射问题,其多层形式的计算复杂度与多层快速多极子相当。
This paper mainly discusses the realization of the large complex targets electromagnetic scattering computation . high frequency scattering predication can accelerate electromagnetic simulation computation . this paper discusses electromagnetic scattering predication using physical optical ( po ) , geometrical optical ( go ) and physical theory of diffraction ( ptd ) 大电尺寸复杂目标的电磁计算存在数据存储量及计算量巨大的情况，使用高频估算方法可以明显提高电磁散射的仿真计算速度，本文主要研究物理光学高频电磁散射估算方法的实现。
The radar target identification based on artificial neural network is the protagonist of the chapter 4 . bp network and wavelet network are used to classified the emulational radar targets . with the powerful capability of non - linnear identification of bp neural network , its ’ born limitations such as local extremum , slow convergence etc . can be reformed by the wavelet network , which is a network with a wavelet function embedded into the node of a bp network 研究了基于人工神经网络模型的雷达目标hrrp识别方法。 bp人工神经网络强大的非线性处理能力,在解决复杂目标分类识别时有优势;小波神经网络针对bp网络的不足,将bp网络和小波变换相结合,在网络收敛、网络初始化方面弥补了bp网络的部分缺陷,其识别性能和抗噪性能与bp网络相比有所提高。
The backward scattering field of extended target is approximated as the synthesis of many strong scatter centers on target , and geometric optical method is used in establishing deterministic model of a aircraft in the paper , the model is used to evaluate the performance of frequency diversity in suppressing glint at last 本文将复杂目标后向散射回波近似为目标上若干强散射中心回波的合成，结合几何光学法得到了某种飞机目标的确定性模型，并用该模型评定频率分集对角闪烁抑制的改善性能。
Based on the concept of the rcs and the theory of the basic electromagnetic scattering , this dissertation discussed the application of the physical optics ( po ) to the rcs of bodies modeled with nurbs surfaces , and completed an integrate software with the display , transfer , shelter handling and modification of the models 本文围绕复杂目标雷达截面( rcs ) rcs的概念及基本电磁散射理论，讨论了基于nurbs曲面模型的物理光学法的应用，同时完成了集模型显示、修改、变换、消隐及rcs计算于一体的综合软件开发。
The main works and results are as follows : 1 . by use of one order multiple scattering theory , light scattering and reflection by a single coating layer is analyzed . the variance of radiation intensity , bidirectional reflection distribution function ( brdf ) and laser radar scattering cross section with coating layer parameters is given , with the effect of rough contrast on bidirectional reflection distribution function 本文主要研究了单层和多层涂层结构介质的光散射特性，以及近场条件下复杂目标对激光波束的散射，其主要工作如下： 1 、采用一阶多重散射近似理论分析单层涂层对光波的散射和反射，计算并讨论了辐射强度、双向反射分布函数和单位面积激光雷达散射截面随涂层结构参数的变化规律，数值分析了粗糙基底对双向反射分布函数的影响。
An attention - based image recognition model is proposed . when analyze complex visual field or pattern , visual attention mechanism is used to detect saliency features in the image and drive the fixation point to scan the saliency features sequentially . during each fixation , the local pattern at the fixation point is memorized or matched . there are two parts in the memory of a complex pattern , the memory of local patterns that constitute the complex pattern and the memory of space relations between local patterns . corresponding to memory process , the recognition process also contains two parts , the matching of local patterns and the matching of space relations between local patterns . an object is recognized only when there are enough numbers of local patterns is matched and the space relations between these local patterns are correct 在扫描到每一个关键特征区时，将对该区域附近的局部模式进行记忆或匹配。对一个复杂目标的记忆将包括2部分，一部分是对局部模式的记忆，即组成该目标的各“部件”的模式另一部分是对各局部模式之间的空间关系的记忆，即组成该目标的各“部件”之间的结构关系。与记忆过程对应，识别过程也包括2部分，一部分是对局部模式的匹配，另一部分是对各局部模式之间结构关系的匹配。
