基于点云重建复杂城市建筑环境的电磁计算

李玉峰; 周晨; 张富彬; 夏国臻; 朱建桦

doi:10.12265/j.cjors.2021198

基于点云重建复杂城市建筑环境的电磁计算

doi: 10.12265/j.cjors.2021198

武汉大学电子信息学院, 武汉 430072

详细信息

作者简介:
李玉峰：（1997—），男，安徽人，武汉大学电子信息学院硕士研究生，研究方向为电波传播与城市电磁环境建模

周晨：（1983—），男，湖北人，武汉大学电子信息学院教授，主要研究方向为空间环境探测技术和电波传播应用

张富彬：（1998—），男，河南人，武汉大学电子信息学院博士研究生，主要研究方向为电离层物理、电磁兼容技术

通讯作者:
周晨 E-mail: chenzhou@whu.edu.cn

中图分类号: 中图分类号文献标志码 A
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出版历程
- 收稿日期: 2021-07-28
- 网络出版日期: 2021-10-25

Electromagnetic calculation of complex urban architectual environment based on point cloud reconstruction

School of Electronic Information, Wuhan University, Wuhan 430072, China

摘要

摘要: 在现代城市环境中，地形地貌地物复杂，精确评估电波传播效应十分困难. 针对传统城市建筑环境电磁计算物理建模不够精确的问题，提出利用多视角立体视觉的方法对城市复杂建筑环境进行基于点云的三维重建，获取精确的三角网格模型，并通过机器学习图像分割的方法获取城市环境边界电磁属性;在此基础上进行基于一致性绕射理论的射线追踪电磁计算，从而获取区域范围内的电磁态势分布. 通过在不同分辨率网格模型上计算，并与COST231-Hata模型和实际测量结果对比，高分辨率网格模型的均方根误差为6.065 5 dB，证明了本文建模及计算方法的有效性.
- 复杂环境 /
- 点云 /
- 表面重建 /
- 射线追踪 /
- 一致性绕射理论 /
- 电磁态势
Abstract: In a complex city environment, it is very difficult to accurately evaluate the effect of radio wave propagation due to the complex terrain, landforms and features. In order to solve the problem that the traditional physical modeling of electromagnetic computing in urban architectual environment is not accurate enough, this paper proposes a multi-view stereo method to reconstruct the complex urban architectual environment based on point cloud, obtain the accurate triangular mesh model, and obtain the electromagnetic attributes of urban environment boundary by machine learning image segmentation method. On this basis, the ray tracing electromagnetic calculation based on uniform theory of diffraction is carried out to obtain the electromagnetic situation distribution in the region. By calculating on different resolution grid models, and comparing with the COST231-Hata model and actual measurement results, the root mean square error of the high-resolution grid model is 6.0655dB, which proves the effectiveness of the modeling and calculation methods in this paper.
- complex environment /
- point cloud /
- surface reconstruction /
- ray tracing /
- uniform theory of diffraction /
- electromagnetic situation

HTML全文

图 1 点云重建流程图

Fig. 1 Point cloud reconstruction process

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图 2 电磁介质语义分割

Fig. 2 Semantic segmentation of electromagnetic media

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图 3 区域密集点云

Fig. 3 Regional dense point cloud

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图 4 单栋建筑密集点云

Fig. 4 Dense point cloud of a building

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图 5 简单几何模型

Fig. 5 Simple geometric model

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图 6 表面重建获取网格模型及简化

Fig. 6 Surface reconstruction to obtain mesh model and simplification

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图 7 反射绕射传播示意图

Fig. 7 Schematic diagram of reflection and diffraction

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图 8 点对点多径传播

Fig. 8 Point-to-point multipath propagation

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图 9 图8局部图

Fig. 9 Partial view of Fig.8

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图 10 区域卫星图

Fig. 10 Regional satellite image

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图 11 355 MHz电磁态势图

Fig. 11 355 MHz Electromagnetic situation

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图 12 1800 MHz电磁态势图

Fig. 12 1800 MHz Electromagnetic situation

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图 13 COST231-Hata模型电磁态势图

Fig. 13 Electromagnetic situation of COST231-Hata model

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图 14 实测示意图

Fig. 14 Schematic diagram of actual measurement

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图 15 仿真与实测结果对比

Fig. 15 Comparison between simulation and actual measurement

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图 16 接收点1结果分析

Fig. 16 Result analysis of Rx1

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图 17 接收点6结果分析

Fig. 17 Result analysis of Rx6

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图 18 三种模型边长统计

Fig. 18 Statistics of the model's edge length

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图 19 各接收点误差

Fig. 19 Error of each receiver

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表 1 仿真参数表

Tab. 1 Simulation parameters table

仿真参数	取值
建筑数量	66
基站高度/m	30
发射功率/W	0.1
载波频率/MHz	355/1 800
虚拟接收机数量	5 551
天线模式	全向天线
带宽/MHz	1
波形	正弦波
极化方式	垂直极化

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表 2 实验参数表

Tab. 2 Experimental parameters table

实验参数	取值
实验区域	1.8 km×1.2 km
接收机数量	6
输出功率/W	20
发射天线频率/MHz	355
天线带宽	15
发射机采样点	8
发射机高度/m	2
天线模式	全向天线
天线增益/dBi	3.5
波形	正弦波
极化方式	垂直极化

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表 3 三种模型结果对比

Tab. 3 Comparison of 3 model results

模型	面元数	边数	均方根误差/dB	计算时间/s
模型1	17 470	40 246	6.065 5	82
模型2	8 734	20 111	7.922 9	48
模型3	4 384	6 576	8.805 2	21

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