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CLASSIFICATION OF MOBILE LASER SCANNING POINT CLOUDS OF URBAN SCENES EXPLOITING CYLINDRICAL NEIGHBOURHOODS
Point clouds Mobile Laser Scanning Classification Feature extraction Cylindrical Approach 3D Mapping
2018/6/5
This paper presents our work on automated classification of Mobile Laser Scanning (MLS) point clouds of urban scenes with features derived from cylinders around points of consideration. The core of ou...
PLANE-BASED REGISTRATION OF SEVERAL THOUSAND LASER SCANS ON STANDARD HARDWARE
Terrestrial laser scanning registration plane-to-plane correspondences stochastic modelling large networks
2018/6/5
The automatic registration of terrestrial laser scans appears to be a solved problem in science as well as in practice. However, this assumption is questionable especially in the context of large proj...
USAGE OF MULTIPLE LIDAR SENSORS ON A MOBILE SYSTEM FOR THE DETECTION OF PERSONS WITH IMPLICIT SHAPE MODELS
LiDAR Mobile Laser scanning MLS Person Detection Classification
2018/6/4
The focus of this paper is the processing of data from multiple LiDAR (light detection and ranging) sensors for the purpose of detecting persons in that data. Many LiDAR sensors (e.g., laser scanners)...
SPACE-BORNE LASER ALTIMETER GEOLOCATION ERROR ANALYSIS
Laser altimetry Error analysis Footprints Pointing angle Range Geolocation accuracy
2018/6/5
This paper reviews the development of space-borne laser altimetry technology over the past 40 years. Taking the ICESAT satellite as an example, a rigorous space-borne laser altimeter geolocation model...
VALIDATING A WORKFLOW FOR TREE INVENTORY UPDATING WITH 3D POINT CLOUDS OBTAINED BY MOBILE LASER SCANNING
Tree inventory Mobile Laser Scanning Point Cloud Data Tree classification
2018/6/5
Urban trees are an important component of our environment and ecosystem. Trees are able to combat climate change, clean the air and cool the streets and city. Tree inventory and monitoring are of grea...
INDIVIDUAL ROCKS SEGMENTATION IN TERRESTRIAL LASER SCANNING POINT CLOUD USING ITERATIVE DBSCAN ALGORITHM
DBSCAN rocks segmentation terrestrial laser scanning fluvial transport
2018/6/5
The fluvial transport is an important aspect of hydrological and geomorphologic studies. The knowledge about the movement parameters of different-size fractions is essential in many applications, such...
AUTOMATED CALIBRATION OF FEM MODELS USING LIDAR POINT CLOUDS
Point clouds LiDAR rasterization FEM analysis bending moment torque
2018/6/5
In present work it is pretended to estimate elastic parameters of beams through the combined use of precision geomatic techniques (laser scanning) and structural behaviour simulation tools. The study ...
半导体激光器双波长光纤耦合模块的ZEMAX设计
半导体激光器 光纤耦合 激光合束 ZEMAX
2018/3/7
为了发挥单管半导体激光器的优势，获得光纤耦合模块多波长、高功率、高亮度的光束输出，利用ZEMAX软件仿真模拟，设计了一种单管光纤耦合模块。此模块将32支输出波长分别为915 nm、975 nm，输出功率为15 W的单管半导体激光器，经过微透镜组快慢轴光束整形、空间合束、偏振合束、波长合束以及光束聚焦等一系列工艺后，耦合进芯径200 μm、数值孔径0.22的光纤。模拟结果显示，光纤输出功率467.4...
针铁矿和针铁矿—胡敏酸复合体对Se(Ⅳ)吸附机制
针铁矿 针铁矿—胡敏酸复合体 等温吸附 硒(Ⅳ) X—射线光电子能谱（XPS）
2018/4/28
研究了针铁矿和针铁矿—胡敏酸复合体对Se(Ⅳ)的吸附机制。结果表明：针铁矿和复合体对Se(Ⅳ)的最大吸附容量分别为0.202 mmol g-1和0.159 mmol g-1。针铁矿的等温吸附数据适合用Langmuir模型拟合，而Freundlich模型更适合描述复合体的等温吸附过程。针铁矿的等电点（IEP）在7.0附近，复合体的IEP<3.0；当pH=4.0时，它们的表面电位分别为46.6 mV和...
光电编码器与棱体轴线平行度对转角误差的影响
平行度 倾斜方向 测试误差 误差
2018/3/7
光电轴角编码器轴线与棱体轴线不平行会降低转角误差测试结果的置信度，为了减小光电轴角编码器转角测试误差，将由光电轴角编码器轴线与棱体轴线不平行引入的转角测试误差控制在光电轴角编码器转角误差的1/3~1/5以内，建立了由光电轴角编码器轴线和棱体轴线平行度引入的转角测试误差数学模型及Y向偏置数学模型。由仿真结果可知，光电轴角编码器转角测试误差和Y向偏置随转角的增大呈现周期性变化，周期分别为π和2π，棱体...
利用球-旋转椭球模型研究上皮组织散射特性
组织模型 光散射 穆勒矩阵 Monte Carlo
2018/3/7
组织模型在组织成像机理及光学疾病诊断技术的研究和改进中发挥着重要作用。然而上皮组织细胞中不仅包含球形散射体，往往还包含椭球形散射体。目前对包含椭球散射体的上皮组织模型的研究还鲜有报道。建立了上皮组织的球-旋转椭球散射模型，利用Monte Carlo算法仿真分析了模型参数的变化对前向散射光强分布及穆勒矩阵极分解参量的影响。结果表明，旋转椭球散射系数、体积和长短轴比的增大均会导致组织模型的去偏作用增强...
基于偏振信息反演土壤湿度的方法
土壤湿度 偏振反射模型 反演方法 定量
2018/3/7
为了实现基于偏振信息反演土壤湿度的目的，建立了土壤表面的偏振反射模型，并在可见光波段内开展了土壤湿度与反射光偏振信息的实验研究。首先，根据几何光学理论和测量数据建立了土壤表面的偏振反射模型。其次，制备了不同湿度的土壤样品，搭建了实验平台，并在多种入射观测条件下，使用高精度偏振成像探测系统获取了样品的偏振信息。然后，对实验数据进行分析来验证模型。最后，建立了模型中微面元坡度均方差、漫反射等效系数和折...
实现惯测坐标系正交同步的系统级标定技术
正交同步 抗干扰 系统级标定
2018/3/7
文中研究目的有两个方面，一是在外场条件下实现低精度测试设备标定高精度捷联惯性导航装置；二是标定过程中实现惯性测量坐标系正交同步，进而提高捷联惯导动态导航精度。据此，文章在深入分析惯性测量坐标系空间相对关系的基础上，对惯性测量坐标系进行正交化，并通过建立正交化后惯性测量坐标系之间的失准角模型，从而完成基于惯性测量坐标系非正交角及失准角的系统级标定滤波器的构建以及系统级标定方案的设计，同时，针对外场测...
提出了一种基于复合光纤滤波器的在室温下稳定输出多波长掺铒光纤激光器，该激光器由两个级联球状结构的马赫-增德尔干涉仪（MZI）和一个双折射光纤滤波器-Lyot滤波器组成。球状结构MZI是由光纤熔接机在一段单模光纤（SMF）放电设计而成的。Lyot双折射光纤滤波器是利用一段保偏光纤（PMF）和两个偏振控制器（PC）连接而成，该结构可以诱导非线性偏振旋转效应和双折射光纤效应来抑制模式竞争产生多波长。Ly...