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ASSESSMENT OF A DEVELOPED COMBINED POINT/LINE–BASED PROJECTIVE EQUATIONS
Mapping Development Comparison
2015/6/1
This paper presents the results of the assessment of the developed techniques for line-based and combined point/line-based eight
parameters projective equations. The developed equations were impleme...
USING STEREO IMAGES TO DENSIFY LIDAR DATA POINTS AT WHERE NEEDED
Image Building Application Algorithm
2015/6/1
For many applications, dense Lidar data is often needed. For instance, for telecommunication antenna network design, 1 meter
spacing Lidar data would be needed for downtown area of a big city. Howev...
FROM SINGLE-PULSE TO FULL-WAVEFORM AIRBORNE LASER SCANNERS: POTENTIAL AND PRACTICAL CHALLENGES
Laser scanning Digitisation Retrieval Vegetation
2015/6/1
Airborne laser scanning, often referred to as lidar or laser altimetry, is a remote sensing technique which measures the round-trip
time of emitted laser pulses to determine the topography of the Ea...
APPLICATION OF LIDAR DATA AND 3D-CITY MODELS IN VISUAL IMPACT SIMULATIONS OF TALL BUILDINGS
Tall Buildings 3D Isovists Visual Impact
2015/5/7
The paper examines possibilities and limitations of application of Lidar data and digital 3D-city models to provide specialist urban analyses of tall buildings. The location and height of tall build...
A BOX-COUNTING METHOD TO CHARACTERIZE DEGREES OF FOLIAGE CLUMPING USING AIRBORNE AND SIMULATED LIDAR DATA
LiDAR leaf area index foliage clumping
2015/5/7
Monitoring forest productivity and health is key to sustainable ecosystem management and informed decision making. A key parameter used in monitoring forest resources is the leaf area index (LAI), w...
LASER SCANNING AND PHOTOGRAMMETRY: 21ST CENTURY METROLOGY
laser scanning photogrammetry integration
2015/3/6
New technologies often turn heads the first time they appear. Laser scanning is one such new technique, which has
impressed many users by the ability of point clouds to provide an understanding of c...
THE POTENTIAL OF NON-CONTACT CLOSE RANGE LASER SCANNERS FOR CULTURAL HERITAGE RECORDING
Laser scanners close range cultural heritage recording
2015/3/6
The use of laser scanning methods for the close range measurement of fixed objects has recently
become popular in the design and manufacture of automobiles, and in body scanning. Laser scanning
inst...
激光跟踪仪测角误差补偿
角度测量 误差补偿 谐波分析
2014/10/15
由于激光跟踪仪的角度测量精度直接影响仪器的测量精度，本文提出了用自准直仪结合多面棱体对跟踪仪金属圆光栅测角误差进行离散标定的方法。研究了基于谐波分析的误差补偿方法，取金属柱面圆光栅测角误差中幅值较大且相位基本不变的谐波分量建立了补偿模型，避免了最小二乘法不收敛的问题。分析了标定测角误差的不确定度，结果显示：水平测角精度补偿前后分别为1.60"和0.90"，俯仰测角精度补偿前后分别为4.89"和0....
冷轧生产线硅钢激光辅助切割有限元模拟
激光辅助切割 硅钢 高速切割 有限元模拟
2014/6/10
研究了激光加热辅助圆盘剪高速切割技术，以解决现有冷轧生产线硅钢切边技术存在的微裂纹、应力、毛刺和边浪等问题。建立了激光加热温度场有限元分析模型，根据生产线上圆盘剪加工的实际过程，探讨了数值模拟中热源的加载形式，研究了激光对板材进行辅助加热时各个工艺参数如激光功率、光斑尺寸以及激光入射角度对切割工艺的影响，并通过实验对工艺参数进行了优化。最后，进了验证实验。实验结果显示：当激光加热点运动至圆盘剪刃口...
针对现有激光雷达目标姿态估计算法对遮挡较为敏感的问题,提出了一种新的三维姿态估计算法。分析了现有算法的内在本质和地面装甲目标固有的表面结构特性,提出了投影点云密度熵(PDE)特征,研究了PDE特征与目标姿态的内在关系,给出了对目标点云迭代地进行旋转投影并寻找PDE最小值以实现三维姿态估计的方法。采用25类地面装甲目标的激光雷达点云数据进行仿真实验,分析了自遮挡、遮挡以及噪声下的估计性能,讨论了参数...
利用点扩散函数(PSF)研究了入射激光的偏振态和光束的束腰直径对激光扫描共聚焦显微镜(LSCM)分辨率的影响。根据Wolf和Richards的矢量衍射积分, 建立了LSCM N-1层界面下的照明PSF模型, 对零层和两层界面下的PSF进行了计算分析。结果显示:在零层界面下, 圆偏振光入射的PSF在xy平面内关于焦点旋转对称, 半峰全宽为0.43 μm, x向线偏振光入射时PSF在x、y方向的半峰全...
为了研究非傍轴部分相干厄米-余弦-高斯光束传输特性，运用Wigner分布函数法，从空间域和频率域对非傍轴部分相干厄米-余弦-高斯光束传输特性进行了理论分析，得出了该光束1阶情况下在空间、频率域系统的解析传输公式及光强分布表达式，分析了这些表达式中3个主要参量f，fσ和g对厄米-余弦-高斯光束在自由空间传输的影响。结果表明，在调制参量g不变时，束腰参量f和相干参量fσ对非傍轴部分相干厄米-余弦-高斯...
在衍射分布的离散计算中，当衍射距离增大时，满足抽样定理的抽样点数会随之增加，为了解决补零算法带来的计算量大、计算机内存溢出等问题，提出了一种频移插值法，在不改变抽样点数的情况下，获得更为丰富的频谱成分，计算每次插值后的光场分布，然后进行线性叠加，从而得到完整的衍射分布。结果表明，该算法可以避开衍射距离增大必须增加抽样点数这一离散计算限制条件，和传统补零算法相比，计算量极大地减小，并降低了对计算机内...
激光等离子体X射线特征谱轮廓诊断
激光等离子体诊断 电子密度 X射线谱仪
2014/8/18
开展了利用X射线特征谱轮廓诊断激光等离子体状态参数的研究。在“神光II”激光装置上，将 0.35 μm频谱激光束聚焦于真空室内固体氯（Cl）元素靶上产生激光氯等离子体，利用高分辨X射线椭圆弯晶谱仪获取高能谱分辨激光氯等离子体辐射的X射线精细结构能谱。用类氢（1s-3p）和类氦（1s2-1s3p）氯离子能级跃迁光谱线的光强度比率计算了激光等离子体的电子温度；然后在假定光性为薄的情况下，利用X射线谱线...