利用TIN和高程梯度进行高程点抽稀

为了解决系列比例尺地形图缩编过程中高程点的抽稀问题,考虑到高程点分布的密度和地形起伏等因素,基于高程点构建了TIN,再结合平均高程面、高程梯度和局部高程最值点,对高程点进行了筛选抽稀。     

剩余高程异常模型工程测量高程转换算法

为了提升工程测量中的高程换算算法精度,设计一种基于棱柱积分法的剩余高程异常转换算法,对比国内地理高程数据及国际上较多测量工程中参照的RTM2006.0高程、RET2012高程、RET2014高程等高程三维模型,发现该算法可以在距离海岸基准线1 800 km之外获得±50 mm以内的高程误差,该精度足以满足国内大部分地区的高程工程测量需求。     

一种快速求场地平均高程的好方法

场地填渣平整,离不开求原始平均高程和填后平均高程.对分布均匀的高程点,一般求平均高程的方法是所有高程数据和除以所有高程点数.但是一块场地高程点少则几百个多则几千个,这些数据处理起来费力费时,且容易出错.下面我介绍一种在AutoCAD 2000中利用AutoLISP程序求平均高程的方法,程序如下:     

井下三角高程代替水准测量的可行性

通过对全站仪三角高程测量精度的分析,论证了井下三角高程测量可以作为井下高程控制的一种手段。并通过一些三角高程测量在实际矿山测量中的应用实例,验证了利用全站仪三角高程测量代替井下水准测量实施井下高程控制的可行性结论。     

GPS拟合高程代替五等水准测量精度的分析与探讨

就GPS高程转换进行研究,论述了GPS高程转换的过程及常用方法,特别对数学模型拟合法进行了讨论,最后通过对某地区GPS拟合高程与水准高程的精度对比分析,提出了利用GPS观测值加已知高程点拟合求待定点高程的方法,论述了等级网GPS拟合高程可以达到的普通几何水准测量精度。     

最实用的设定三角高程反觇测站高程的方法

高程测量的3种基本方法——水准测量、三角高程、GPS高程,其中三角高程方法灵活,施测快速,且对于地形起伏适应性强,目前数字地形图野外数据采集,大多采用全站仪三角高程。     

山区全站仪三角高程与GPS拟和高程比较精度之分析

通过在山区测量中,全站仪三角高程与GPS拟和高程的比较,可得出小面积山区航测成图项目外业像控点高程测量可用GPS拟和高程替代全站仪三角高程作业方法的结论。     

地形图高程差值批处理的方法探讨

本文介绍了地面沉降与高程异常对地形图的高程影响,并利用VBA实现了地形图高程差值的批处理,实现了高程数据的快速更新。     

一种三角高程测量改进方法的精度分析

针对传统三角高程测量相对水准测量精度较低的问题,本文将新三角高程测量方法作为研究重点,从三角高程测量原理出发,根据误差传播率,推导出了计算传统三角高程测量和新三角高程测量高差精度的数学模型。实验对比分析了新三角高程测量与水准测量、传统三角高程测量的精度情况,结果表明新三角高程测量方法简便灵活,省时省力,能提高作业效率,同时达到了三等水准测量精度要求,具有广泛适用性。     

DEM线性建模过程中的高程误差传播

在建立数字高程模型(DEM)时,基于规则格网数据和基于三角形网数据的线性建模是常用的方法。在建模过程中,结点的高程误差会随之传播。研究了DEM在基于规则格网数据和基于三角形网数据的线性建模过程中的高程误差传播问题,推导出了在结点高程误差相关情形下的高程误差传播公式,求出了在规则格网和不规则格网面上的平均高程传播误差。平均高程传播误差可以作为DEM线性插值过程中高程误差传播的度量指标。     

战场地理空间信息可视化系统设计与研究

对当前流行的3DGIS系统进行了介绍,并研究提出了采用面向对象的方法来表达3D场景中的空间数据,基于栅格金字塔模型来组织和管理地形数据,基于视点相关的地形LoD方法实现了大范围漫游,基于参数化3D建模方法和矢量地物LoD来实现地物数据的建模和可视化的方法,设计和构建西北地区战场地理空间信息可视化系统(3DMGIS)。     

新形势下摄影测量学课程教学改革探讨

随着视频卫星、无人机和计算机技术的普及与发展,摄影测量技术已经从传统地势侦察与地形测绘推广应用于智慧城市建设的各个领域,多学科的交叉融合是摄影测量发展的必经之路。为了满足传统摄影测量向智能摄影测量发展要求,本文在原有摄影测量教学的基础上,引入倾斜摄影测量与计算机视觉方面的相关知识,优化和完善摄影测量教学内容,丰富教学实践。本文教学改革探讨旨在扩展摄影测量教学前言知识,满足现代社会对创新型和实践型摄影测量人才的需求,为摄影测量学科适应新时代的发展提供了理论基础。     

设计模式和重构在土地信息系统中的应用

设计模式和重构对于解决土地信息系统需求变化问题,具有重要意义,可以实现可复用性。本文并结合土地信息系统的开发实例,详细论述如何运用重构准则实现抽象工厂、装饰等模式。旨在促进土地信息系统开发中注重设计模式和重构准则的应用,实现软件设计的复用,提高土地信息系统的质量和开发效率。     

土地调查市级数据库建设若干问题处理方法

全国第二次土地调查工作的外业调查和县级数据库建设即将结束,为实现对二调成果的集中管理,保证调查成果充分应用于国土资源管理日常业务,为土地资源宏观规划和管理决策提供快速、准确、翔实的基础数据,满足市级对县级土地调查数据管理和应用的迫切需求,市级数据汇总及数据库建设是十分重要的一项内容。笔者根据自己参加第二次土地调查的外业...     

Monitoring mangrove forests: Are we taking full advantage of technology?

Mangrove forests grow in the estuaries of 124 tropical countries around the world. Because in-situ monitoring of mangroves is difficult and time-consuming, remote sensing technologies are commonly used to monitor these ecosystems. Landsat satellites have provided regular and systematic images of mangrove ecosystems for over 30 years, yet researchers often cite budget and infrastructure constraints to justify the underuse this resource. Since 2001, over 50 studies have used Landsat or ASTER imagery for mangrove monitoring, and most focus on the spatial extent of mangroves, rarely using more than five images. Even after the Landsat archive was made free for public use, few studies used more than five images, despite the clear advantages of using more images (e.g. lower signal-to-noise ratios). The main argument of this paper is that, with freely available imagery and high performance computing facilities around the world, it is up to researchers to acquire the necessary programming skills to use these resources. Programming skills allow researchers to automate repetitive and time-consuming tasks, such as image acquisition and processing, consequently reducing up to 60% of the time dedicated to these activities. These skills also help scientists to review and re-use algorithms, hence making mangrove research more agile. This paper contributes to the debate on why scientists need to learn to program, not only to challenge prevailing approaches to mangrove research, but also to expand the temporal and spatial extents that are commonly used for mangrove research.     

基于GIS的开发区土地集约利用评价

作为城镇发展和土地利用的重点区域,开发区在促进经济高速发展中发挥了举足轻重的作用,已经成为产业升级、区域发展的推动器和科技创新基地。但在开发区土地利用中,重扩张轻挖潜、重规模轻效率、重引资轻规划等问题仍未得到有效解决。为保证经济社会可持续发展、提高土地资源持续保障能力、缓解土地供需矛盾,必须按照落实科学发展观和建立资源节约型社会的要求,着力改变开发区外延扩张、用地粗放的局面,建立集约高效的开发区用地模式。采用统计模型分析法和特尔斐法,结合ArcGIS等地理信息系统软件,对都江堰市经济技术开发区土地集约利用进行定量化评价,并试图探讨集约度的合理水平和促进土地集约利用的途径与措施。     

北京市测绘成果管理的现状与建议

测绘成果是重要的信息资源,总结了现有测绘成果管理的国家政策法规.对北京市和兄弟省市在政策法规与标准建设、机构建设、测绘成果的汇交与发布进行了对比分析.提出进一步完善测绘成果管理政策法规;成立专门的测绘成果管理机构,加强对测绘成果汇交情况的监管;建立与测绘成果汇交有关的数据标准;加大经费投入,保障测绘成果管理工作的顺利进行;集成整合规划监督测量成果,降低测绘成果生产成本;研发相关网站,促进测绘成果分发共享,大力开展测绘产品增值服务.     

基于GIS的历史自然灾害数据库设计与实现

本文提出了利用空间数据库和GIS技术整理分析方志、古籍的研究方法,结合《中国古代重大自然灾害和异常年表总集》中记载的各种自然灾害信息,采用面向对象的Geodatabase数据模型,建立了中国全区域的,多朝代的,多自然灾害要素的,带有地理特征的关系型数据库,实现了数据的统一描述与管理,并根据专题数据制作了单一灾害要素、多种灾害要素的专题地图,可视化分析了历史自然灾害的时空分异,最后将地图进行网络发布以实现数据共享。结果表明GIS有利于方志、古籍的数字化整理与分析,实现了以信息技术保护、传播和有效的利用方志资料。     

A Visual Art Interface to an Embedded Sequence of Maps

The role of art in relation to maps is being reappraised on the basis of a perceived ability to depict aspects of a place that maps alone cannot. Many as opposed to one perspective on a place communicates more fully the essence of that place (with art as a valuable source of qualitative geospatial data) and so maps and art should be presented in the same visualization package. This paper outlines the development and implementation of an interface where a scanned painting forms the mode of access to an embedded sequence of maps. The interface is used to represent the history and habitat extent of the kea (alpine parrot) in New Zealand from pre human colonization times through to their present, limited range to a speculation on their future habitat. The painting and the map (in what has been termed in the literature as an anti-map / map combination) are in their own separate layers and joined by an interactive link. The interface harnesses the ability of visual art to aggregate multiple themes, locations and times into a single cohesive image, coupled with map composition and symbology that complements the painting. The ability to contain many temporal instances is close to the comic strip frame (and instances of Renaissance art) in particular, with, in this case, an implicit time frame from left to right on the painting. The use of an artistic image minimizes use of text to depict events, due to the visual and narrative power of the painting.     

Populating digital earth: improving access to Chinese remote sensing data for terrestrial applications

Global change has a significant impact on the lives of humankind. Earth observation can help to better understand our earth and cope with global change. With the availability of more reliable environmental data sets, digital earth is becoming a popular way to monitor the Earth and provide information to researchers and decision makers on environment protection, disaster mitigation, and social benefits. Therefore, accessing data with lowering costs is essential for digital earth. Nevertheless, there are big challenges in ensuring the feasibility of access to Chinese remote sensing data. This paper outlines some of the main challenges in realizing data sharing, provides an analysis of the core reasons leading to these challenges, and proposes recommendations to overcome the challenges. Amongst the main challenges are differences in data policy to gain access to satellite data, diverse data formats, and delivery mechanisms. The major challenge for the decision makers is to define a more open policy and for the scientist the challenge is to implement these polices for the benefit of all. This paper proposes that governments should adopt policies encouraging more open distribution and access to their data, in order to generate an improved digital earth with increased benefits to human society.