U.S.-Italy Cooperative Research: Visibility Characteristicsof Digital Terrain Models

该奖项将使伦斯勒理工学院的George Nagy教授和位于意大利热那亚的意大利国家研究委员会的Bianca Falcidieno博士能够继续1981年开始的成功合作。在研究的前一阶段开发的一种算法用于在适当的三角地形模型上定义称为可见性地图的数据结构。这张地图显示任意两点之间是否有畅通无阻的视线。该算法与现有的隐藏面算法相关，但结合了基于问题独特特征的概念。此外，可视性模型的全局性为定义地形实体提供了一个有用的替代偏导数的方法。其他算法也被开发出来，应用得到的可见度图对最佳观测点进行排序。调查人员要考虑的问题包括：视线（电视、调频、雷达）通信和监视问题；隐藏的路径;定位和导航；从能见度图到原始地形数据的逆变换；数据压缩;以及山脊、山谷等重要地形特征的提取。美国PI将带来计算机视觉、光学扫描和模式识别、遥感、地理数据处理和计算几何的工程应用方面的合作经验。意大利方面将提供计算地理、计算机制图、计算机图形学、实体建模和图论方面的专业知识。这项研究预计将对计算几何、地形信息系统和电信作出贡献。

This award will enable Prof. George Nagy of Rensselaer Polytechnic Institute and Dr. Bianca Falcidieno of the Italian National Research Council in Genova, Italy, to continue a successful collaboration that started in 1981. An algorithm developed in the previous stage of the research is used to define a data structure, called a visibility map, on an appropriately triangulated terrain model. The map shows whether there is an unimpeded line of sight between any two points. The algorithm is related to existing hidden-surface algorithms, but incorporates concepts based on the unique characteristics of the problem. Additionally, the global nature of the visibility model provides a useful alternative to partial derivatives for defining topographic entities. Other algorithms have been developed applying the resulting visibility map to rank order the best observation points. Among the problems to be considered by the investigators are: line of sight (television, FM, radar) communications and surveillance problems; hidden paths; orientation and navigation; the inverse transform from the visibility map to the original terrain data; data compression; and the extraction of significant terrain features such as ridges and valleys. The U.S. PI will bring to the collaboration experience with computer vision, optical scanning, and engineering applications of pattern recognition, remote sensing, geographic data processing, and computational geometry. The Italian side will provide expertise in computational geography, computer cartography, computer graphics, solid modeling, and graph theory. The research is expected to contribute to computational geometry, to topographic information systems, and to telecommunications.