机载激光雷达数据的地物分类方法及处理方式

机载激光雷达技术衍生于传统的工程测量中的激光测距技术,是传统雷达技术与现代激光技术结合的产物,是遥感测量领域的一门新兴技术。随着机载激光雷达数据的不断发展,其在基础测绘、城市三位建模、铁路、电力等领域有着越来越广泛的应用,然而机载激光雷达数据刚扫描完的数据全部存放到一个点云层,不利于后期数据的分析、应用。因此,本文以处理吉林省白城市激光点云数据的方式为例,介绍了机载激光雷达点云数据的处理方式及地物分类的原则。     

基于GPGPU的数学形态学LiDAR点云快速滤波方法

对机载激光雷达获取点云数据进行滤波时,因其数据量大,往往会耗费很多时间。在传统数学形态学LiDAR点云滤波方法基础上,提出利用基于GPU的并行技术,将大量密集运算分配到众多计算单元上并行执行,达到快速滤波的目的。通过相应的实验,验证了利用GPU并行计算技术实现的LiDAR点云快速滤波的正确性与可行性。     

机载激光LiDAR在密林山区测绘中的应用研究

为解决山区测绘的高程问题,本文利用机载激光雷达采集了山区点云并通过点云滤波的手段获取了山区地表点的高程数据,通过实验验证和分析可知,机载激光雷达在山区的地表点云有着很高的精度和密度,能够很好地满足山区地形测绘的要求。     

机载点云数据生产DEM的关键技术探讨

从机载航摄仪中获取的点云数据出发,提出了点云制作DEM的生产工序流程及作业中的注意事项,重点论述点云精度、点云滤波、DEM制作等关键技术,并对点云滤波算法进行优化改进,使之更好地应用于项目生产中,提高了工作效率.     

基于TerraSolid的平原地区点云数据滤波方法

Terra Solid是处理机载激光雷达数据的常用软件。本文介绍了用Terra Solid软件对点云数据进行滤波的方法,解释了滤波过程中各参数的含义,通过实验比较了不同的参数设置对平原地区滤波结果的影响,最后,提出了对平原地区点云数据进行滤波的方案。     

应用机载激光雷达数据制作DEM的方法探讨

通过对机载激光雷达数据的分析、点云处理、DEM处理,探讨应用机载激光雷达数据制作DEM的方法,并通过实例介绍应用机载激光雷达数据制作DEM的生产流程。     

浅析机载激光雷达点云数据处理与DEM制作

机载激光雷达测量技术是当代航空、航天遥感最具代表性之一的高新测绘技术,它集全球定位、惯性导航、激光测距等高新技术于一体,工作效率、数据精度高,能迅速获取地理空间物体的三维信息数据,一定程度上解决了传统航空、航天摄影测量获取地面三维信息不便的难题,机载激光雷达测量技术实际上已经代表了对地观测领域一个新的技术发展方向。本文重点探讨机载激光雷达点云数据制作DEM的关键生产技术流程,以及在生产过程中的机载激光雷达点云数据常见问题处理方法。     

基于DGNSS+INS紧组合POS的小型机载激光雷达在抽水蓄能中的应用

为解决抽水蓄能电站大高差、植被覆盖区域传统测量技术测量困难以及航摄测量精度低等问题,将飞马多旋翼无人机D2000与小型机载激光雷达D-LiDAR2000引入抽水蓄能电站测量中。本文以贵州省某抽水蓄能电站可研设计阶段测量为例,应用小型机载激光雷达D-LiDAR2000获取测区原始三维点云数据,并基于后处理DGNSS+INS紧组合解算的POS对原始点云进行了融合。经过植被透过性分析、航带误差分析、平面和高程精度检查,结果表明基于DGNSS+INS紧组合POS融合的小型机载激光雷达D-LiDAR2000的点云数据能够满足抽水蓄能电站数字高程模型、大比例尺地形图等产品的生产需求。     

一种基于移动曲面拟合的机载LIDAR点云数据滤波方法

针对机载LIDAR点云数据滤波问题,在分析张小红教授提出的移动曲面拟合法滤波的基础上,结合机载LIDAR点云数据的特点,引入虚拟格网技术,提出一种基于移动曲面拟合的机载LIDAR点云数据滤波方法,并通过实验验证了该方法的可行性和适用性。     

基于距离图像的分块曲面LiDAR点云滤波方法

机载激光雷达点云滤波是获取高精度数字高程模型的关键,也是国内外研究的热点.这里采用区块索引机制对激光雷达点云进行分块曲面滤波;利用距离图像的像素位置信息指导分块数的确定.试验结果表明,该方法可有效滤除非地面点,从而保留地面部分点云,具有一定实用价值.     

高等学校道路勘测设计实习改革探索与实践

根据现行的测量和道路测设作业方式,充分利用GNSS-RTK技术,研究设计适合道桥专业特点的实习方式,提出基于GPS-RTK和全站仪一体化的实习模式,提高学生的动手和思考能力,使实习操作与工程实践实现完美衔接。     

Spectra and vegetation index variations in moss soil crust in different seasons,and in wet and dry conditions

Similar to vascular plants, non-vascular plant mosses have different periods of seasonal growth. There has been little research on the spectral variations of moss soil crust (MSC) over different growth periods. Few studies have paid attention to the difference in spectral characteristics between wet MSC that is photosynthesizing and dry MSC in suspended metabolism. The dissimilarity of MSC spectra in wet and dry conditions during different seasons needs further investigation. In this study, the spectral reflectance of wet MSC, dry MSC and the dominant vascular plant (Artemisia) were characterized in situ during the summer (July) and autumn (September). The variations in the normalized difference vegetation index (NDVI), biological soil crust index (BSCI) and CI (crust index) in different seasons and under different soil moisture conditions were also analyzed. It was found that (1) the spectral characteristics of both wet and dry MSCs varied seasonally; (2) the spectral features of wet MSC appear similar to those of the vascular plant, Artemisia, whether in summer or autumn; (3) both in summer and in autumn, much higher NDVI values were acquired for wet than for dry MSC (0.6 ∼ 0.7 vs. 0.3 ∼ 0.4 units), which may lead to misinterpretation of vegetation dynamics in the presence of MSC and with the variations in rainfall occurring in arid and semi-arid zones; and (4) the BSCI and CI values of wet MSC were close to that of Artemisia in both summer and autumn, indicating that BSCI and CI could barely differentiate between the wet MSC and Artemisia.     

2013年国土资源科技成果统计分析

本文对2013年在国土资源部科技成果管理办公室登记的科技成果进行了系统总结,从成果来源、类别、评价方式、评价水平、完成单位、完成人员、经费投入和成果应用情况8个方面介绍了国土资源科技成果基本情况,并针对目前国土资源科技成果登记、推广应用和共享方面存在的问题,提出了对策建议。     

哈尔滨CORS建设及其在测量中应用

介绍哈尔滨市GPS连续运行参考站系统的建设情况,详述系统原理和各组成部分的功能,以及在测量中的应用。     

数据库知识发现技术及其在测绘中的应用

详细介绍了数据挖掘与数据库中的知识发现(KDD)技术,给出了KDD的定义以及KDD具体实现的3种处理模型,并从GIS和遥感影像分析两个方面论述了KDD技术在测绘中的应用.     

数据库知识发现技术及其在测绘中的应用

详细介绍了数据挖掘与数据库中的知识发现 (KDD)技术 ,给出了KDD的定义以及KDD具体实现的3种处理模型 ,并从GIS和遥感影像分析两个方面论述了KDD技术在测绘中的应用     

Evaluating Topological Queries in Linked Data Using DBpedia and GeoNames in Switzerland and Scotland

This article explores the practicability and assesses the quality of searches for Wikipedia pages of topologically related administrative divisions in Switzerland and Scotland via Linked Data. To this end, the quality of searches in the English and German versions of DBpedia is compared, as is that of searches in GeoNames and DBpedia using DBpedia's links to GeoNames or a manually created list of links. In addition, the effects of updates to Swiss municipality borders in the English version of DBpedia on standard quality metrics are studied. It turns out that live searches are practicable with acceptable performance, but that the quality of searches in terms of recall and precision is acceptable only if DBpedia is queried via GeoNames and DBpedia's links to GeoNames are replaced by manually created links. Searches for Scottish unitary authority wards perform poorly for all approaches investigated. Recall and precision are strongly influenced by changes in municipality borders, with a relatively long latency suggesting that, at least in some cases, administrative changes propagate slowly into DBpedia. These results have important implications for those seeking to use location as a means to link data.     

Rough集理论及其在GIS属性分析和知识发现中的应用

介绍了Rough集理论的概念与方法,并将其全面引入GIS领域,归纳整理出Rough集理论用于GIS中属性分析和知识发现的一整套方法,为GIS的属性分析和知识发现开辟了一条新途径。     

Malaria incidence in Nairobi,Kenya and dekadal trends in NDVI and climatic variables

The primary objective of this research was to determine if the remotely-sensed metric, Normalised Difference Vegetation Index (NDVI) and ground-collected dekadal climatological variables were useful predictors of future malaria outbreaks in an epidemic-prone area of Nairobi, Kenya. Data collected consisted of 36 dekadal (10-day) periods for the variables rainfall, temperature and NDVI along with yearly documented malaria admissions in 2003 for Nairobi, Kenya. Linear regression models were built for malaria cases reported in Nairobi, Kenya, as the dependent variable and various time-based groupings of temperature, rainfall and NDVI data from the dekads in both the current and the previous month as the independent variables. Data from 2003 show that malaria incidence in any given month is best predicted (R²  = 0.881, p < 0.001) by the average NDVI for the 30 days including the final two dekads of the previous month and first dekad of the current month, and by the average rainfall for the 30 days including the three dekads of rainfall data from the prior month. Forecasting an outbreak in an epidemic zone would allow public health entities to plan for and disseminate resources to the general public such as antimalarials and insecticide impregnated bed nets. In addition, vector control measures could be implemented to slow the rate of transmission in the impacted population.