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Geometrical Modeling by NURBS Surface and RCS Computing by Visualization for Complex Targets
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作者 Zhou, Yong Liu, Tiejun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1997年第1期13-21,共9页
A novel approach to compute the high frequency radar cross-section (RCS) of complex targets is described in this paper.From the three views or the sectional views of the target, target is geometrically modeled by non-... A novel approach to compute the high frequency radar cross-section (RCS) of complex targets is described in this paper.From the three views or the sectional views of the target, target is geometrically modeled by non-uniform rational B-spline (NURBS) parametric surfaces using the software CNFEOV developed by oneself which constructs NURBS representation of complex target from engineering orthographic views. RCS is obtained through PO, PTD, MEC and IBC techniques. When calculating RCS of the target, it is necessary to get the unit normal vector to surface illumi- nated by radar and the value Z which is the distance from the point on the surface to radar. ln this novel approach, the unit normal vector to the surface can be obtained either by the Phong rendering model, in which the color components (RGB) of every pixel on the image are equal to the coordinate components of the normal, or by the NURBS expressions. The value Z can be achieved by software or hardware Z-buffer. The effects of the size of image on the RCS of target are discussed and the correct method is recommended. The RCS of the perfect conducting sphere, cylinder and dihedral as well as the coated cylinder, as some examples, are computed. The accuracy of the method is verified by comparing the numerical results with those obtained by using other methods. 展开更多
关键词 rcs visualization computation geometrical modeling.
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玉米雌穗几何造型研究 被引量:8
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作者 肖伯祥 郭新宇 +1 位作者 郑文刚 王丹虹 《工程图学学报》 CSCD 北大核心 2007年第2期64-67,共4页
通过对玉米雌穗形态结构的观测分析,提出了基于形态结构特征参数的玉米雌穗三维形态数学模型和可视化实现方法。根据玉米雌穗结构特征,雌穗建模过程包括雌穗轴线设计、果穗柄造型、穗轴造型、苞叶造型和籽粒造型5个阶段。对于不同玉米品... 通过对玉米雌穗形态结构的观测分析,提出了基于形态结构特征参数的玉米雌穗三维形态数学模型和可视化实现方法。根据玉米雌穗结构特征,雌穗建模过程包括雌穗轴线设计、果穗柄造型、穗轴造型、苞叶造型和籽粒造型5个阶段。对于不同玉米品种,通过设置模型参数,即可在计算机上实现雌穗的三维显示,具有较强的真实感效果。该模型可控性强,易于操作,可满足玉米雌穗数字化设计的需要。 展开更多
关键词 计算机应用 玉米雌穗 数字化设计 几何造型 三维可视化
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