共查询到20条相似文献,搜索用时 156 毫秒
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介绍了作者合作研发出的Chhzwdzx等值线绘制软件的基本功能,以及该软件在气象数据等值线绘制中的效果展示。该软件简单易学、实用性强,用户可通过改变绘图界面中等值线间隔、画笔粗细和颜色、网格密集程度、系统自带底图和注释等其他自定义条件,得到所需等值线图。该软件所绘制的图形准确、美观,为气象、测绘等领域的绘图工作提供了便捷。 相似文献
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针对机场噪声的特征及分布特点,提出了一种基于路径栅格的机场噪声等值线追踪算法。通过构造有效网格、建立具有顶点和的路径栅格,在等值线追踪过程中唯一确定下一个等值点,能够快速生成等值线图,然后根据自身特点对等值线进行光滑,最后,为了方便查看不同区域的噪声影响情况,需要对等值线用不同的颜色进行填充处理。 相似文献
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本文主要探讨和实现Delaunay三角网生成等值线在气象行业中的应用。通过自动站的经纬度(离散点)生成三角网,根据气温、降水量等实时数据绘制等值线并填色。目前生成等值线在气象行业广泛使用的方式有两种,一是程序中内嵌Sufer控件;一是采用行业软件Micaps。无论哪种方式都无法高效率的适应B/S架构的系统,从而难以在公共气象服务中广泛应用。本文将以百度地图为例,后台构建算法,通过数据接口方式输出分层的等值线经纬度数据,调用百度地图API和Canvas在Web上实时绘制等值线并填色。 相似文献
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描述了调频广播与航空导航业务之间干扰的现状、产生原因及电磁兼容分析的研究情况。以国际电联ITU-R SM.1009-1建议书为理论基础,介绍了B1类干扰的定义及产生机理,根据建议书提供的B1类干扰兼容性评估标准及通用估算方法,提出了B1类干扰最大防护距离及等值线的兼容分析方法,并给出了用该方法进行B1类干扰分析的详细步骤和流程,分析人员可根据等值线对B1类可能的干扰区域进行预测。 相似文献
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本文对自由曲面的快速反求系统进行了研究。首先将矩形光栅投影在被测表面上,利用光栅投影法测量自由曲面上每点高度信息。然后对测量的三维离散数据进行一种特殊的Hermite插值,通过重叠的矩形作用域叠加而形成一个由矩形网格表示的新曲面。最后,采用AutoCAD命令绘制三维自由曲面。 相似文献
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使用NOR-840对会议厅内的21个点测量6个倍频带的声压级。会议厅模型中的座椅采用三种方式表达,分别用Odeon软件计算得到三组数据。对实测值与计算值采用分布曲线、等值线平面图方式表达室内声场,比对它们的差异并提出评价意见供使用者参考。 相似文献
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本文描述了调频广播与航空导航业务之间干扰分析及预测的现状,以ITU-R SM.1009-1建议书为基础,根据B1类干扰产生的原理,提出了B1类干扰最大防护距离及等值线的计算方法,并给出了B1类干扰的详细计算方法和流程。分析人员可根据等值线对B1类可能的干扰区域进行了预测。 相似文献
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辐射单元矩形栅格排列是相控阵天线中最简单的排列方式,也是最常用的一种排列方式。它是把整个阵面划分成许多矩形栅格,每个辐射元占据一个自然格或栅格的交点。而本文对子阵模块间采用三角形栅格而子阵模块内采用矩形栅格的排列方式进行了分析,通过理论分析验证这种排列方式比普通矩形栅格排列有较大优势。 相似文献
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Yee K.S. Jei Shuan Chen Chang A.H. 《Antennas and Propagation, IEEE Transactions on》1992,40(9):1068-1075
It is shown how to use many overlapping conformal grids in the neighborhood of the scatterer while using a rectangular grid away from the scatterer for solving Maxwell's equations. The locally conformal grids allow better approximation of the boundary condition on the scattering object while the rectangular grid preserves the simplicity and accuracy of the regular finite-difference time-domain (FDTD) algorithm. These grids overlap typically about three zones. It is shown how to connect together the calculations done in different overlapping grids 相似文献
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Kuang-Man Huang Pamela Cosman William R. Schafer 《Journal of Signal Processing Systems》2009,55(1-3):113-126
We present a method for tracking and distinguishing multiple C. elegans in a video sequence, including when they are in physical contact with one another. The worms are modeled with an articulated model composed of rectangular blocks, arranged in a deformable configuration represented by a spring-like connection between adjacent parts. Dynamic programming is applied to reduce the computational complexity of the matching process. Our method makes it possible to identify two worms correctly before and after they touch each other, and to find the body poses for further feature extraction. All joint points in our model can be also considered to be the pseudo skeleton points of the worm body. It solves the problem that a previously presented morphological skeleton-based reversal detection algorithm fails when two worms touch each other. The algorithm has many applications in the study of physical interactions between C. elegans. 相似文献
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基于体素化网格下采样的点云简化算法研究 总被引:2,自引:0,他引:2
针对三维点云数据冗余量大、重建时间长、效率低等问题,提出一种基于体素化网格下采样的点云简化算法。该算法首先求出点云数据集的最小三维长方体包围盒,把点云数据划分进三维体素栅格中去;其次计算点云的k邻域,进行曲面法向量估计;然后,在三维体素栅格中选择满足要求的数据点,实现点云下采样;最后,调用Power Crust对下采样点云数据进行曲面重建,在三维可视化类库Visualization Toolkit(VTK)进行显示。实验结果表明,该算法能够加快三维点云数据的重建速度,较好地保持了点云特征,提高曲面重建的效率和鲁棒性,适合实时处理。 相似文献
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In this paper, we closely scrutinize the spatial and spectral properties of aperiodic halftoning schemes on rectangular and hexagonal sampling grids. Traditionally, hexagonal sampling grids have been shunned due to their inability to preserve the high-frequency components of blue-noise dither patterns at gray-levels near one-half, but as will be shown, only through the introduction of diagonal correlations between dots can even rectangular sampling grids preserve these frequencies. And by allowing the sampling grid to constrain the placement of dots, a particular algorithm may introduce visual artifacts just as disturbing as excess energy below the principal frequency. If, instead, the algorithm maintains radial symmetry by introducing a minimum degree of clustering, then that algorithm can maintain its grid defiance illusion fundamental to the spirit of the blue-noise model. As such, this paper shows that hexagonal grids are preferrable because they can support gray-levels near one-half with less required clustering of minority pixels and a higher principal frequency. Along with a thorough Fourier analysis of blue-noise dither patterns on both rectangular and hexagonal sampling grids, this paper also demonstrates the construction of a blue-noise dither array for hexagonal grids. 相似文献
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传统的高光谱图像混合像元分解技术包括端元提取和估计每个端元的混合比例.虽然很多模型都能得到可以接受的解混结果,但是一些未知端元的存在使得结果在包含未知端元的像素点处出现偏差.因此,提出了一种基于支持向量数据描述的高光谱图像混合像元分解算法.首先高光谱图像数据被分成类内和类外两部分,类内是完全由已知端元数据混合的像素点,而类外数据是包含未知端元的像素点.两类数据交界处被认为是已知端元和未知端元混合的数据.然后再对这些像素点进行混合像元分解,分别对仿真数据和真实高光谱图像进行实验.结果表明该算法可以有效地解决因存在未知端元对解混精度的影响,而且能给出未知端元的解混分量.该方法的解混结果几乎不受未知端元的影响,优于直接解混结果 相似文献
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提出一种新的反射面网格构造方法——网格合并方法,它在保证精度的同时,很大程度上缩短了物理光学方法的计算时间。通过与等角网格、方形网格、匹配点网格的对比,说明了网格合并方法的优点,最后给出了一个用网格合并方法分析卡塞格仑双反射面天线的实例。 相似文献
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Cheng Huang Zeyu Zhao Wei Wang Xiangang Luo 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(7):700-708
In this letter, a kind of metamaterial superstrate based on rectangular metallic grids is presented to enhance the directivity
of patch antenna at two frequency bands for two orthogonal polarizations. According to the periodic boundary condition, the
influences of its important geometry parameters are investigated in detail by simulating its unit cell. It is found that the
transmission peak frequency is intimately related to the size of rectangular metallic grid. Then, a dual band dual polarization
patch antenna with metamaterial is studied and compared with conventional patch antenna. It is demonstrated that by introducing
the proposed metamaterial superstrate, the gain of the patch antenna is improved by 9.5 dB at 14.1 GHz for x polarization and 12 dB at 15.4 GHz for y polarization, respectively. 相似文献
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为了解决目前复杂环境下电力线提取精度及鲁棒性低的问题,提出了一种基于激光点云的电力线自动提取方法。通过主成分分析确定输电线路的主方向,将长距离输电走廊划分为多个空间网格,以应对地形起伏变化时植被点云对提取算法的干扰;再通过一种自顶向下的全新滤波算法剔除每个空间网格的地物点,根据点云密度分布差异实现电力线和电塔的自动分离;另外, 提出半径搜索算法对分离后的结果进行处理,得到单条电力线的激光点云数据。结果表明,所提出的方法对电力线的提取精度高达99.69%,针对不同连接塔型和不同地形都具有很好的鲁棒性。该研究在输电通道空间结构的自动分析领域以及智能巡检领域具有良好的工程应用价值。 相似文献