矢量电子地图的线目标在线简化

为了适应实时ＧＩＳ的变化比例尺显示与网络ＧＩＳ的快速矢量数据传输，提出了数字地图的在线综合概念，讨论了对线目标的在线简化算法。提出的两个在线简化算法都是对ＤＰ简化算法进行改造，使算法对时间的复杂度从θ（ｎ）￣θ（ｎ＾２）的乘法运算改进为θ（１）￣θ（ｎ）的赋值算，并讨论了减少算法所涉及的空间复杂度的可能性。     

ＧＩＳ中平面三角化的优化算法

ＧＩＳ中平面三角化的优化算法黄杏元，马劲松（南京大学大地海洋科学系）地理信息系统（ＧＩＳ）输出的产品中，等值线图是一种重要的表现形式。对具有一组离散点数据的平面进行三角剖分是绘制等值线囹等的关键步骤。此前，用计算机部训成平面三角网的算法在时空特性方面...     

面向对象的GIS结构设计

本文提出了一种以地理实体为中心加空间数据结构模型－面向对象的ＧＩＳ结构模型。在此基础上，讨论了利用规范关系存贮ＧＩＳ中的各种基本数据，以及用ＮＦ２（Ｎｏｎ－ＦｉｒｓｔＮｏｒｍａｌ－Ｆｏｒｍ）的嵌套结构描述和构造面向对象的几何数据，从而实现了面向对象的ＧＩＳ结构设计与管理，提高了ＧＩＳ系统的生命力，简化了系统的开发进程。     

数学形态学在GIS空间分析中的应用

讨论了数学形态学在基于栅格数据结构的地理信息系统（ＧＩＳ）空间分析中的广泛应用。提出了基于形态变换的ＧＩＳ空间操作（图层叠置、缓冲区建立、邻城分析和图元量算）方法，网络最短路径的形态学算法，应用灰度级形态学解求通视图的新思路。     

遥感图像处理与地理信息系统

本文简要介绍了遥感图像处理技术与ＧＩＳ的关系，概述了遥感图像处理技术的发展状况及其在ＧＩＳ中的应用，讨论了遥感（ＲＳ）与ＧＩＳ结合的现状及前景。     

质数长度序列的FFT算法

本文导出了质数长度序列的Ｗｉｎｏｇｒａｄ ＦＦＴ算法，对不贩运算次数和算术平衡提供了可选性，讨论了它们在ＶＡＸ、ＩＢＭ３０９０ＶＦ和ＩＢＭＲＳ－６０００机上的执行情况，处理器在执行浮点数加法，浮点数乘法和浮点数加乘运算时具有相同的时延，所以，本文中的变形算法将所有浮点数的乘法用加乘运算代替，用张量积公式产生的变形算法于各种机型。     

基于MapInfo平台的线对象分割算法

ＭａｐＩｎｆｏ 是目前国内较流行的ＧＩＳ 应用软件开发平台, 有着较高的性能价格比。但其某些功能往往不能满足ＧＩＳ 应用软件的开发要求。文中针对ＭａｐＩｎｆｏ 分割功能的不足,给出了线对象（ｐｏｌｙｌｉｎｅ） 的分割算法及其实现。     

战术军事的地理信息系统数据模型分析

数据模型是对客观世界现象抽象概括的结果,是建立地理信息系统（ＧＩＳ）的基础,从不同角度观察世界产生的不同视图。文中从ＧＩＳ技术在军事战术方面应用的特点出发,提出了战术军事地理信息系统（ＭＧＩＳ）的数据模型,并从几何、拓扑、属性及三维空间信息组织几方面对其进行了讨论。     

亚洲的遥感和地理信息系统——AIT院长访谈录

Ｎｏｒｔｈ教授于１９８３年加入ＡＩＴ（ＡｓｉａｎＩｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏｌｏｇｙ）并担任院长。他领导全院从事遥感（ＲＳ）和地理信息系统（ＧＩＳ）工作，并率先加入了亚洲地区ＲＳ培训中心，该中心是ＵＳＡＩＤ于１９８２年在泰国创建的，为亚洲地区提供ＲＳ和ＧＩＳ的短期专业培训，直到自然资源和管理学科的学位课程（从１９８７年起）。这些科目现在由环境、资源与发展学院的空间技术应用与研究部讲授。在１９９６年６月《亚太ＧＩＳ》杂志对Ｎｏｒｔｈ教授的访问中，Ｎｏｒｔｈ教授谈了他对以下几个方面问题的看法：（１）亚洲ＧＩＳ产业发展现状；（２）亚洲ＧＩＳ实现的主要障碍；（３）对ＧＩＳ和ＲＳ技术应用领域的乐观估计；（４）ＡＩＴ在亚洲ＧＩＳ产业发展中扮演的角色     

GIS环境下空间要素的制图综合方法

本文首先分析了制图综合在ＧＩＳ空间数据输出中的作用，并从讨论制图的基本方法入手，探讨了在ＧＩＳ矢量型和栅格型数据结构下制图综合中选取、简化、概括和移位的实现方法，尤其是基于数学形态学的栅格数据要素的综合方法，最后讨论了在ＧＩＳ中实现制图综合的合理工作流程制定的原则。     

阿克苏河-塔里木河水系水质污染遥感监测与评价

 采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的 污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体 污染变化曲线,得出污染物浓度随着远离上游而增加。     

Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data

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.     

使用FME与VBA提取机场方格网高程数据

因受机场工程设计软件的测量数据容量限制,基于LiDAR采集、点云分类后得到的地面点云数据LAS不能完整应用于目前设计软件进行设计计算。本文通过对拟选技术方案的筛选,提出了利用FME Workbench数据处理功能,结合VBA编程获取外部方格网平面数据的方法。该方法在FME Workbench中实现了地面点云数据构建TIN、采用逐点内插方法从TIN中提取方格网高程数据、等高线生成及相应图形处理与成果输出。最终通过实际算例证明了该方法的有效性。     

Landslide risk analysis between Giri and Tons Rivers in Himachal Himalaya (India)

The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies.     

Gravity Changes Before Large Earthquakes in China: 1998-2005

Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200...     

GNSS系统及其技术的发展研究

阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议.     

“4D”技术及其应用

介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。     

Virtual Australia: its key elements – know,think, communicate

Abstract

Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised.     

自动车辆定位导航系统中传感器的误差分析

对国界定位导航系统中几种常见的辅助传感器所产生的误差进行了分析，导出了不同传感器的误差模型。这些误差模型是估计车辆位置的扩展卡尔曼滤波器的基础，同时也为选择适当的传感器提供了理论根据。