【作者】 陈鹏；

【导师】 吴玲达；

【作者基本信息】 国防科学技术大学 ， 控制科学与工程， 2007， 博士

【摘要】 在现代战争中,对战场电磁环境的描述一直是制约电子对抗指挥员实施准确、高效指挥的关键环节;能否取得电磁控制权,不仅依赖于投入装备的性能,很大程度上也取决于电子对抗指挥员对电磁情势的准确判断以及对电子对抗作战力量的合理部署及调配。雷达是影响战场电磁环境的主要元素之一,如何将它的作用,尤其是受复杂环境影响后的作用以形象的方式展现给指挥员和训练员,以期从非技术层面上把握优势和暴露问题,使其对瞬息万变的战场环境产生更深刻的理解和领悟,从而能从更高层次掌握战场态势,把握战争全局,是未来数字化战场环境不可回避的问题。传统的雷达作用范围表现形式主要是二维的,不够灵活和直观。本文根据不同的应用需求,分别基于雷达方程和雷达波损失两种途径研究了三维雷达作用范围模型的构造问题,设计并实现了模型构造、模型简化与绘制的相关算法,以提高表现的效率和逼真度。在理论研究和算法实践过程中,根据所研究的内容以及所要解决的问题,有针对性地提出了一些新思路和新算法。具体来说,论文的创新点和贡献主要体现在以下几个方面:●借鉴三维空间数据场可视化领域中的数据生成、数据精炼与处理、可视化映射、绘制以及显示等五个步骤,按照数据场建立、数据预处理、三维模型生成和集成表现四个步骤提出了一个虚拟战场环境中三维雷达作用范围表现框架。●提出了一种基于雷达方程的三维雷达作用范围可视化算法。利用虚拟战场环境提供的数字地形数据,基于雷达方程估算出雷达的最大作用距离,以自由空间中雷达作用范围的三维表现为基础,研究了单峰对雷达作用范围的影响,进而得到连续地形影响下的三维雷达作用范围模型,主要适用于大规模虚拟战场表现中精度要求相对较低的情况。●从雷达波传播的角度出发,在基于高级传播模型计算平面内网格点传播损失的基础上,提出了一种虚拟三维策略,即联合多个平面数据构造三维传播损失数据场,从数据场可视化的角度提出了基于轮廓线构造雷达最大作用范围模型的算法,为表现雷达作用范围中的内部细节,提出了利用等值面提取构造雷达作用范围三维网格模型的算法。●从简单的四面体情况出发,推演得到基于六面体网格等值面提取的硬件加速算法,从而将等值面提取过程转移到图形处理单元上去执行。在研究数据场数据预处理、输入输出数据到纹理的映射以及等值面提取算法移植等关键问题的基础上,提出了一种三维雷达作用范围模型的硬件加速生成算法。●设计了一种视点相关且支持拓扑结构改变的网格模型动态简化算法。为得到高逼真度的“剧烈”简化,采用一般顶点对收缩作为简化的基本操作,使得在简化需要时能合并空间上不相连的对象。利用自适应距离阈值选择来控制候选顶点对的数目,并通过综合了几何和属性信息的误差权重来确定简化操作的顺序和精度。在此基础上,通过对简化后的数据进行再组织,使其形成一种视点相关的多分辨率结构,从而能够根据视点参数的变化动态地生成适当细节的简化模型,或者在不同细节模型之间进行快速转换。●设计并实现了一个虚拟战场环境中三维雷达作用范围表现的原型系统——3DRCRepresent,对虚拟战场环境中三维雷达作用范围表现框架及其相关技术进行了应用和验证,并在相关的项目中得到了应用。更多还原

【Abstract】 In modern war, the description of electromagnetic environment is a key factor which restricts the electronic counterwork commander to command well, truly and efficiently. Whether to get predominance in electromagnetic control not only depends on performance of the equipments, but also on nice judgment of electromagnetic situation and reasonably deployment of electronic counterwork power. Radar is one of the most primary elements which affect the electronic environment in battlefield. How to represent the Radar effect vividly to commander and drillmaster, especially the effect under complex environment, so can they hold advantages and discover problems, then generate more profound comprehension and apperception, accordingly hold entire warfare from higher level and hold the battlefield situation in time, becomes a crucial problem in the future Digital Virtual Battlefield Environment.Traditional manners of representing Radar coverage are mostly in 2D, which are not intuitive or agile. For different application requirements, this thesis researched two methods to construct 3D Radar coverage model separately based on Radar equation and electromagnetic wave propagation. Furthermore algorithms related to model constructing, model simplifying and rendering were designed and implemented for higher efficiency and fidelity.In the process of theory researching and algorithm practicing, based on contents to be researched and problems to be resolved, some creative algorithms and methods have been proposed. In detail, the highlighted ideas and main contributions of this thesis are described as follows:For reference, five steps of data filed visualization in 3D space such as datum generation, datum refinement and process, visualization mapping, rendering and displaying were used. A framework of 3D Radar coverage representation in virtual battlefield environment was put forward according to following four steps: data field building, data preprocess, 3D model generation and integrated representation.The advantage of digital terrain data provided by virtual battlefield environment was taken to estimate the maximum range Radar can detect based on Radar equation. Based on the 3D representation of Radar coverage in free space, according to geometric optic method, the influence of a single peak was investigated, and then an algorithm was proposed to represent the 3D Radar coverage affected by single peak. Then 3D coverage influenced by continuous peaks was get. This algorithm is best applicable for cosmically virtual battlefield environment which requires relatively low precision.Started from electromagnetic wave propagation, propagation loss on grid nodes in plane was calculated based on APM. Then a virtual 3D strategy was designed to combine multi in-plane loss value to construct a 3D data field. From the data field visualization point of view, an algorithm of construct maximum detection coverage model was proposed based on 2D contours. For representation of details in the coverage, another model construction algorithm was put forward based on isosurface extraction.For relieving the burden of CPU, started from the simple tetrahedron case, hardware accelerated isosurface extraction algorithm of hexahedron case was deduced. Then the process of isosurface extraction was moved from CPU to GPU. After a series of key problems such as datum preprocess, in/output mapping to texture and isosurface extraction algorithm, etc were resolved, hardware accelerated 3D Radar coverage model construction was implemented.A view-dependent mesh dynamic multiresolution data structure was designed which can support topological structure modification. In order to produce high fidelity and drastic simplifications of complex models, the algorithm needed to combine disjoint parts of the models. So the general vertex pair contraction operation was used which could collapse vertex pairs that were not connected by an edge. The number of candidate vertex pairs was limited by adaptively selecting the distance threshold and defining a unified error metric that combines both geometric and attribute error to control the order of simplification. Based on the sequence of vertex pair contraction operations, by reorganizing the simplified data a view dependent multiresolution data structure was built, so could the proper detailed simplified model be generated or the rapid transformation between different LOD models be implemented according to the view point parameters.A prototype system of 3D Radar coverage representation in virtual battlefield environment named 3DRCRepresent was designed and implemented, which gave a sound support to our 3D Radar coverage representation framework in virtual battlefield environment and related techniques. And some parts of this system were applied in related projects.更多还原