共查询到20条相似文献，搜索用时 46 毫秒
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地理信息系统与地图学教育 总被引：2，自引：0，他引：2
本文在简明扼要地叙述地理信息系统（ＧＩＳ）及地理信息系统教育的发展特点,系统全面地分析ＧＩＳ与地图学、地图可视化与ＧＩＳ可视化的密切关系的基础上,就新时期的地图学教育,在师资人员培养、课程设置、教学内容选择、教学实验方法等方面进行了探讨。 相似文献
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JAVA—GIS软件开发的新工具 总被引：1，自引：0，他引：1
Ｉｎｔｅｒｎｅｔ的迅速发展和ＷＷＷ的面世给传统的ＧＩＳ软件开发提出了新的挑战,本文通过对Ｊａｖａ特点的阐述,论述了Ｊａｖａ成为ＧＩＳ软件开发的新工具的可能性和必然性,笔者认为在不久的将来,Ｊａｖａｓ必将取代Ｖｉｓｕａｌ Ｂａｓｉｃ和ＶｉｓｕａｌＣ＋＋成为ＧＩＳ软件开发的新工具。 相似文献
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计算机技术的迅速发展，使得ＧＩＳ的功能、特点也随之而发生变化，尤其是近几年计算机大容量存贮介质、多媒体技术、可视化技术等被引进ＧＩＳ中，已使传统的地图学理论发生了新的变化。 相似文献
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作者曾经利用扫描矢量化软件Ｉ／ＲＡＳＢ和Ｉ／ＧＥＯＶＥＣ在ＧＩＳ和数字地图中进行了各种各样的应用研究。本文着重介绍Ｉ／ＲＡＳＢ和Ｉ／ＧＥＯＶＥＣ等在ＧＩＳ和地图数字化中的应用方法，包括矢量文件和光栅文件。 相似文献
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我国地图学与ＧＩＳ的新发展张清浦（中国测绘科学研究院）９０年代以来，我国地图学与地理信息产业发展迅速，新图种、新系统、新技术和新方法层出不穷，呈现出蓬勃发展的喜人形势，受到国际同行专家的高度重视。我国地图学和ＧＩＳ的研究和应用已开始步人世界先进行列，... 相似文献
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自本世纪 6 0年代世界上第一台计算机制图系统诞生以来 ,数字地图制图已经走过了三十多年的历程。其理论、技术、设备和应用都发生了深刻的变化。如今它的主要领域包括 :ＭＤＢＳ研究与实用ＭＤＢＳ的建立 ;ＧＩＳ、ＧＰＳ与ＲＳ的集成 ;建立全自动化的地图生成系统 ,提高地图生产效率 ;虚拟现实技术及其应用研究等等。无论上述哪个研究领域都有一个地理信息可视化的问题。可视化 ,也称作科学计算可视化 (ＶｉｓｕａｌｉｚａｔｉｏｎｉｎＳｃｉｅｎｔｉｆｉｃａｌＣｏｍ ｐｕｔｅｒ) ,其定义为 :“可视化是一种计算方法 ,它将符号或数据转换… 相似文献
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数字地图制图向地理信息系统发的若干问题分析 总被引：9，自引：0，他引：9
一、引 言数字地图制图与地理信息系统 (ＧＩＳ)都以空间地理信息的存取、处理、分析与表达为研究对象 ,是地图学在数字信息时代的发展与延续。但相比而言 ,数字地图制图强调空间地理信息的传输和表达 ,而ＧＩＳ则以空间地理信息的处理与分析为主 ,从应用的角度看 ,ＧＩＳ无疑具有更广阔的发展空间。数字地图制图必须在现有技术发展的基础上加强空间 (地图 )分析功能 ,即在保持地图表达的模拟性、艺术性的基础上向ＧＩＳ发展转化 ,才能够一方面提高ＧＩＳ的可视化表达质量 ,另一方面深化数字地图制图的应用层次 ,拓展其应用范围。但到目前… 相似文献
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利用高级语言＋OCX数字制图控件开发中小型GIS软件 总被引：3，自引：0，他引：3
本语文交接停顿同用于数字地图应用软件开发的嵌入式ＯＣＸ控件ＭａｐＯｂｊｅｃｔｓ与微软公司（ＭｉｃｒｏＳｏｆｔ）的高级语言Ｖｉｓｕａｌ Ｒａｓｉｃ相结合,来开发满足各种不同用户需求的中小型ＧＩＳ软件,作者在南京市分层分户图形编辑与管理系统的开发中应用此方法,并获得成功。 相似文献
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Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data 总被引：5，自引：0，他引：5
C. Bhuiyan R.P. Singh F.N. Kogan 《International Journal of Applied Earth Observation and Geoinformation》2006,8(4):289-302
The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw. 相似文献
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SVG是一种基于XML的用来描述二维矢量图形和矢量/栅格混合图形的标记语言,虽然SVG不是为了面向地理空间数据发布而制定的标准,但它的许多特性都能被广泛地应用到WebGIS中,从而实现矢量WebGIS。由于SVG通过简单的文本语句描述矢量图像,所以SVG通常数据量很小,并且SVG支持GZIP压缩,所以基于SVG构建WebGIS能减轻网络传输负载,加快地图显示速度。SVG内置了对JavaScript的支持,且SVG可通过DOM解析映像成内存中的树型结构,所以客户层可通过JavaScript对DOM的操作实现对地图的缩放、漫游、查询、图层控制等交互操作。 相似文献
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本文在讨论DDE技术的基础上，对MapInfo的DDE机制的实现作了探讨和分析。根据技园区域GIS的实际开发工作，介绍了利用DDE技术在MapInfo中成功地集成Foxpro和Autocad. 相似文献
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遥感技术在土地利用动态监测中的应用 总被引：8，自引：0，他引：8
金时华 《测绘与空间地理信息》2006,29(1):98-101
主要论述遥感技术在土地监测中的应用,以某地区土地利用动态遥感监测研究项目的运作过程为例进行阐述。首先介绍了土地利用动态监测的具体内容和技术路线。其次,对数据预处理与信息采集的方法与手段进行了探讨。最后,对作业的内、外业主要过程以及应提交的成果作了介绍。 相似文献
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Automatic 3D extraction of building roofs from remotely sensed data is important for many applications including city modelling. This paper proposes a new method for automatic 3D roof extraction through an effective integration of LIDAR (Light Detection And Ranging) data and multispectral orthoimagery. Using the ground height from a DEM (Digital Elevation Model), the raw LIDAR points are separated into two groups. The first group contains the ground points that are exploited to constitute a ‘ground mask’. The second group contains the non-ground points which are segmented using an innovative image line guided segmentation technique to extract the roof planes. The image lines are extracted from the grey-scale version of the orthoimage and then classified into several classes such as ‘ground’, ‘tree’, ‘roof edge’ and ‘roof ridge’ using the ground mask and colour and texture information from the orthoimagery. During segmentation of the non-ground LIDAR points, the lines from the latter two classes are used as baselines to locate the nearby LIDAR points of the neighbouring planes. For each plane a robust seed region is thereby defined using the nearby non-ground LIDAR points of a baseline and this region is iteratively grown to extract the complete roof plane. Finally, a newly proposed rule-based procedure is applied to remove planes constructed on trees. Experimental results show that the proposed method can successfully remove vegetation and so offers high extraction rates. 相似文献
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遥感和GIS技术应用于伊拉克南部Basrah省土地利用/覆盖变化及城市扩张研究(英文) 总被引：2，自引：0，他引：2
In recent years, land use/cover dynamic change has become a key subject that needs to be dealt with in the study of global
environmental change. In this paper, remote sensing and geographic information systems (GIS) are integrated to monitor, map,
and quantify the land use/cover change in the southern part of Iraq (Basrah Province was taken as a case) by using a 1:250
000 mapping scale. Remote sensing and GIS software were used to classify Landsat TM in 1990 and Landsat ETM+ in 2003 imagery
into five land use and land cover (LULC) classes: vegetation, sand, urban area, unused land, and water bodies. Supervised
classification and normalized difference build-up index (NDBI) were used respectively to retrieve its urban boundary. An accuracy
assessment was performed on the 2003 LULC map to determine the reliability of the map. Finally, GIS software was used to quantify
and illustrate the various LULC conversions that took place over the 13-year span of time. Results showed that the urban area
had increased by the rate of 1.2% per year, with area expansion from 3 299.1 km2 in 1990 to 3 794.9 km2 in 2003. Large vegetation area in the north and southeast were converted into urban construction land. The land use/cover
changes of Basrah Province were mainly caused by rapid development of the urban economy and population immigration from the
countryside. In addition, the former government policy of “returning farmland to transportation and huge expansion in military
camps” was the major driving force for vegetation land change. The paper concludes that remote sensing and GIS can be used
to create LULC maps. It also notes that the maps generated can be used to delineate the changes that take place over time.
Supported by the Al-Basrah University, Iraq, the Geo-information Science and Technology Program (No. IRT 0438)China). 相似文献
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地理数据库的关系模型及其实现 总被引：1，自引：0，他引：1
本文从以图论观点分析地理实体入手,系统阐述了地理数据库关系模型的设计法和过程。作者于1984年4～9月间在微型机上设计建立了关系型地理数据库的实方验系统(RGDB)。该系统采用了本文提出的关系模型,采用了可动态扩库的子库组合结构,这种结构具有灵活性和提高空间利用率的优点。RGDB含有多种功能的数据操作命令,除了具有一般检索功能外,还能进行“开窗”选取和十分“自由”的映象选取。本文对RGDB系统的主要性能和实现途径作了扼要介绍。 相似文献
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随着城市面貌日新月异,地下管网的建设也在持续推进,作为城市的地下“神经网络”,全天24 h保障城市的正常运转和发展。本文以实现城市管网管理系统的高可用、无插件、智能化为目标,采用“地上地下一体”“二三维一体”的设计理念,研究基于WebGL的三维智慧管网系统的关键技术,实现了管线设施管理的信息数字化、空间化与图形化。 相似文献
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We aim a better understanding of the effect of spring-time snow melt on the remotely sensed scene reflectance by using an extensive amount of optical spectral data obtained from an airborne hyperspectral campaign in Northern Finland. We investigate the behaviour of thin snow reflectance for different land cover types, such as open areas, boreal forests and treeless fells. Our results not only confirm the generally known fact that the reflectance of a melting thin snow layer is considerably lower than that of a thick snow layer, but we also present analyses of the reflectance variation over different land covers and in boreal forests as a function of canopy coverage. According to common knowledge, the highly variating reflectance spectra of partially transparent, most likely also contaminated thin snow pack weakens the performance of snow detection algorithms, in particular in the mapping of Fractional Snow Cover (FSC) during the end of the melting period. The obtained results directly support further development of the SCAmod algorithm for FSC retrieval, and can be likewise applied to develop other algorithms for optical satellite data (e.g. spectral unmixing methods), and to perform accuracy assessments for snow detection algorithms.A useful part of this work is the investigation of the competence of Normalized Difference Snow Index (NDSI) in snow detection in late spring, since it is widely used in snow mapping. We conclude, based on the spectral data analysis, that the NDSI -based snow mapping is more accurate in open areas than in forests. However, at the very end of the snow melting period the behavior of the NDSI becomes more unstable and unpredictable in non-forests with shallow snow, increasing the inaccuracy also in non-forested areas. For instance in peatbogs covered by melting snow layer (snow depth < 30 cm) the mean NDSI -0.6 was observed, having coefficient of variation as high as 70%, whereas for deeper snow packs the mean NDSI shows positive values. 相似文献