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首页> 外文会议>Geoscience and Remote Sensing Symposium, 1995. IGARSS '95. 'Quantitative Remote Sensing for Science and Applications', International >Modeling techniques for curved and tapered branches at different microwave frequencies
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Modeling techniques for curved and tapered branches at different microwave frequencies

机译：不同微波频率下弯曲和锥形分支的建模技术

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摘要

The effects of modeling the curvature and tapering of branches for various microwave frequencies are examined. The forest models that are currently being used represent branches as perfect dielectric cylinders. However actual branches are composed of segments decreasing in diameter along the branch length. Adjacent branch segments also have slightly different angles causing branch curvature. In this study, each branch is represented as a collection of cylindrical segments whose sizes and positions are known. The data for the calculations are obtained from actual branch measurements of red pine and jack pine trees using the "tree vectorization" technique which has been developed at the Canada Centre for Remote Sensing. For a given frequency and incidence angle, a curved and tapered branch can be approximated by an equivalent cylindrical branch. The equivalent cylinder can be determined by choosing the size and orientation so that the radiation patterns match closely. For curved branches, the radiation pattern at typical incident angles is calculated by adding the contributions from each branch segment coherently. It is observed that at low frequencies, the parts of the branch with thinner segments do not contribute to scattering. Therefore, the resulting equivalent cylinder is represented by the thicker part of the branch which is closer to the trunk.
机译：研究了对各种微波频率的分支曲率和锥度建模的效果。当前使用的森林模型将分支表示为完美的介电圆柱体。但是，实际的分支由沿分支长度直径减小的段组成。相邻分支段的角度也略有不同，从而导致分支曲率。在这项研究中，每个分支都表示为圆柱形片段的集合，其大小和位置已知。用于计算的数据是使用加拿大遥感中心开发的“树木矢量化”技术从赤松和千斤顶松树的实际分支测量中获得的。对于给定的频率和入射角，弯曲和锥形的分支可以由等效的圆柱分支近似。等效圆柱体可以通过选择尺寸和方向来确定，以使辐射图紧密匹配。对于弯曲的分支，通过将每个分支段的贡献相干地相加，可以计算出典型入射角的辐射方向图。可以看出，在低频下，分支较细的部分对散射没有贡献。因此，所得的等效圆柱体由更靠近树干的分支的较厚部分表示。

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