光盘扫描高斯光束的研究

讨论了扫描光束对高斯参数扫描光点强度分布的影响；给出了高斯参数与中心峰值强度及光点直径的定量关系；展示出焦平面上的三维光强分布图；提出了光盘存贮中高斯参数的选择依据；有效利用无能，获得高性能扫描光点。

小F数衍射微透镜阵列光学性能研究

本文基于小光点扫描 ,在国内首次提出了一种测试小 F数衍射微透镜阵列光学性能的方法 .利用光通信用半导体激光器和探测器建立了一套测试系统 ,并对所研制的大阵列 ,小单元尺寸的多相位菲涅耳衍射微透镜阵列的衍射效率和点扩散函数进行了测试 .结果表明 ,衍射微透镜实际衍射光斑比理论衍射受限光斑扩展不大 ,8相位和 1 6相位石英微透镜的衍射效率分别高达 80 .2 %和 87.5 % ,说明本实验室对多相位的设计理论和制作工艺已基本掌握 。

光存储及恢复技术

光盘存储系统中扫描光束的优化设计=Optimiza—tion of scanning beam in optical disk storagesystem[刊,中]/罗勇,王华,杨华军,高振平,陈宏猷(电子科技大学光电中心。四川,成都(610054))∥激光技术。—1998.22(3)。—191—195利用衍射分析方法,优化扫描光束参数,获得高强度、高质量扫描光点。该理论分析及结论广泛适用于CD,CD—ROM,WORM,MOD及其光盘存储系统。图4表2参5(赵桂云)

A new optimal approach to segmentation of 2D range scans to line sections

In order to obtain a compact and exact representation of 2D range scans,UKF(unscented Kalman filter) and CDKF(central difference Kalman filter) were proposed for extracting the breakpoint of the laser data. Line extraction was performed in every continuous breakpoint region by detecting the optimal angle and the optimal distance in polar coordinates,and every breakpoint area was constructed with two points. As a proof to the method,an experiment was performed by a mobile robot equipped with one SICK laser rangefinder,and the results of UKF/CDKF in breakpoint detection and line extraction were compared with those of the EKF(extended Kalman filter) . The results show that the exact geometry of the raw laser data of the environments can be obtained by segmented raw measurements(combining the proposed breakpoint detection approach with the line extraction method) ,and method UKF is the best one compared with CDKF and EKF.

Pattern Detection in Airborne LiDAR Data Using Laplacian of Gaussian Filter

Methods for feature detection in laser scanning data have been studied for decades ever since the emergence of the technology.However,it is still one of the unsolved problems in LiDAR data processing due to difficulty of texture and structure information extraction in unevenly sampled points.The paper analyzes the characteristics of Laplacian of Gaussian(LoG) Filter and its potential use for structure detection in LiDAR data.A feature detection method based on LoG filtering is presented and ex-perimented on the unstructured points.The method filters the elevation value(namely,z coordinate value) of each point by convo-lution using LoG kernel within its local area and derives patterns suggesting the existence of certain types of ground ob-jects/features.The experiments are carried on a point cloud dataset acquired from a neighborhood area.The results demonstrate patterns detected at different scales and the relationship between standard deviation that defines LoG kernel and neighborhood size,which specifies the local area that is analyzed.

FasFast Triangulation and Local Optimization for Scan Data of Laser Radar

In order to study the triangulation for the point cloud data collected by three-dimensional laser radar,in accordance with the line-by-line characteristics of laser radar scanning,an improved Delaunay triangulation method is proposed to mesh the point cloud data as a triangulation irregular network.Based on the geometric topology location information among radar point cloud data,focusing on the position relationship between adjacent scanning line of the point data,a preliminary match network is obtained according to their geometric relationship.A reasonable triangulation network for the object surface is acquired after the use of local optimization on initial mesh by Delaunay rule.Meanwhile,a new judging rule is proposed to contrast the triangulation before and after the optimization on the network.The result shows that triangulation for point cloud with full use of its own characteristics can improve the speed of the algorithm obviously,and the rule for judging the triangulation can evaluate the quality of network.