关于3维空间查询系统的研究

现有的大部分查询路径的系统都是基于2维的,GoogleEarth的出现将路径查询系统引入到了3维的世界,但GoogleEarth是以鸟瞰的方式向人们展示路径的,不符合人一般行走过程的视觉效果。本文介绍利用VC 6.0、M apOb jects和OpenGL来实现一个能虚拟显示行走过程的3维空间查询系统,从而对OpenGL在G IS软件中的应用进行了探讨。     

实现数字地球中坐标转换与地理对象的查询

地理信息系统已经由2维系统逐渐向3维系统的方向发展。3DGIS可以提供逼真的可视表达方法。在3DGIS系统中3维空间对象包含空间属性信息和非空间属性信息。3DGIS针对数据模型要具有空间分析的功能。参照GoogleEarth利用OpenGL实现数字地球原型系统,并在此基础上提供简单的空间查询功能。     

基于Google Earth楼盘信息查询系统的设计与实现

以GoogleEarth为数据平台,利用VC^＋＋6．0和Google Earth API,设计并实现了面向用户的楼盘信息查询系统;同时,利用ArcGIS Engine进行二次开发,进行缓冲区分析;最后以长沙市小区山语林居为例,验证了系统的可行性与实用性。     

三维GIS空间-属性信息交互查询的设计与实现

阐述了三维查询功能的开发思路,设计了一种三维场景空间信息组织结构和查询功能实现算法,利用Visual C 结合OpenGL运用面向对象技术从底层开发,数据库的连接采用ADO技术,通过实现原型系统表明方法的可行性.     

基于OpenGL的城市管线GIS系统三维模块开发

在深入研究城市管线组成及特点的基础上,基于OpenGL技术和COM技术,从管线的三维显示、三维查询、三维飞行、三维分析等方面设计了城市管线GIS系统的三维模块,并实现了部分功能模块。     

基于OpenGL的DEM三维仿真方法研究

本文介绍了如何利用VC 结合OpenGL实现DEM三维仿真,其中重点介绍了OpenGL的主要功能、DEM模型、VC 中OpenGL的参数设置、高程数据的读取、地形的仿真。最后实现了DEM三维模型的缩放旋转、投影变换、地貌信息、空间查询、人机交互等功能。     

OpenGL与Windows坐标相互转换的实现

基于OpenGL图形库进行开发三维交互系统时,OpenGL世界坐标和Windows窗口坐标转换是不可避免要面临的问题。众所周知,Windows坐标是二维平面坐标,而OpenGL世界坐标是三维右手笛卡尔坐标系。为解决项目开发中这一问题,首先分析了2种坐标系及其转换过程,然后根据三维实体在Windows上显示的原理建立坐标...     

基于三维可视化技术的矿产管理信息系统

本系统借助先进的基于OpenGL的三维可视化技术,利用ADO进行数据库编程,建立计算机辅助的“可视化矿产管理信息系统”,实现矿区地形的地表模型三维立体显示,能够查询分析,形象直观地查阅矿区GIS空间矿脉信息。     

浅谈GoogleEarth二次开发技术

从GoogleEarthComAPI的发布谈起,回顾GoogleEarth的发展历史,介绍基于GoogleEarth为平台的二次开发技术,提供把GoogleEarth应用到现实生活中的思路。     

基于MapX的公路路面管理信息系统设计与关键技术

本文从系统开发平台、系统组成结构、系统功能、空间数据库结构等方面介绍了一个基于MapX的公路路面管理系统设计方案,对系统研制过程中涉及的最短路径查询分析、空间属性查询、动态分段技术、鹰眼功能实现等关键技术问题进行阐述。根据本文设计与技术思路研制了一个地区级公路路面管理信息系统,以江西省抚州市公路网的路面管理信息对系统进行验证。     

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。