GPS小范围测距的两种实现方法

通过对一个特定区域的实际测量,利用GPS测得的各点位置信息,采取两种不同的方法分别计算了两条行进路线的长度,结果表明GPS在短距离测量中具有一定的实际意义。     

增强型列车控制系统

介绍了在青藏铁路使用的增强型列车控制系统的基本组成原理和主要功能特点。     

浅谈数字电力GIS系统的设计

主要介绍了数字电力GIS系统的设计与实现过程。     

A comparison on urbanization of two mega polises in western China in recent 20 yearsversity,

Based on a comparison of the spatial extension modulus and speed of the two megapolis cities in western China, Chongqing and Chengdu, the differences of urbanization characteristics of the two cities were analyzed. The results show that the two cities have different spatial extension modulus and extension speed. The extension speed of Chongqing, the largest mountainous city of China, was slow and its extension direction was along the Yangtze River valley and the Jialing River valley. Chengdu, the largest plain city of western China, had a faster extension speed than Chongqing and a concentric circles extent modulus. The spatial extent modulus and speed were controlled by the natural condition, especially the topography, the policies, the economic development level and the investment of the state central government.     

基于GIS的土地适宜性评价方法研究——以重庆市城口县为例

为了进行土地适宜性评价,首先利用MAPGIS和ARCVIEW进行图层信息采集(数字化),建立区域图形库的同时,建立土地适宜性评价指标体系,采用特尔菲法确定因素权重,并建立GIS系统管理下的各图层(评价因素)空间属性信息数据库,接着利用GIS叠加分析功能,确定土地适宜性评价的最小评价单元,最后利用累加求和模型计算评价单元的分值并划分适宜等级。对城口县土地适宜性评价结果表明,利用GIS对土地适宜性进行评价,其方法切实可行,具有传统的评价不可比拟的优越性。     

基于GIS的新疆高等级公路筑路材料管理系统

依据新疆高等级公路筑路材料的资源现状,采用叠置分析的地理信息系统(GIS)选线方法,研制开发了新疆高等级公路筑路材料GIS管理系统。将筑路材料资源信息及相关的地理背景信息按其数据特性的不同分为图形数据和属性数据两种,并以矢量数据及格栅数据两种结构形式进行表达;利用VB编程语言,基于OLE自动化技术对MapInfo进行二次开发,实现了Accsee数据与MapInfo数据的连接和GPS数据的输入。     

基于GIS的长株潭地区生态环境质量评价研究

在研究生态环境评价的理论与方法的基础上,将地理信息系统开发平台ArcGIS与高级语言开发工具VC 相结合,以Oracle9i作为数据库管理工具,开发出长株潭地区生态环境质量评价信息系统。具体介绍了评价模型的选择,数据存储和处理的方法,系统的功能设计与实现的关键代码。通过该系统对长株潭地区生态环境质量进行评价分级,具有较强的实用性和可操作性,其评价结果具有直观、形象、动态的特点。     

Land potential appraisal for urban land reserve based on GIS: A case of metropolitan area in Chongqing

With the rapid urbanization, land banking has become an important means for rational land use and land configuration optimizing. Rational urban land reserve and supply plan are keys for an urban land banking. GIS has been used to model urban growth, growth at the rural-urban fringe specifically. This paper identifies that the urban land banking potential can be evaluated based on RS and GIS technology. 10 indicators were chosen in the integrated index system. As a case of Metropolitan area in Chongqing, urban land banking potential was evaluated based on RS and GIS technology. With GIS, two steps can help to finish potential analysis of land banking. One is goal driven process, such as the process of planning and definition; the other step is data-driven process, such as the process of Manipulating. The results are used to establish the current land banking plan.     

一种实用GPS授时系统的设计

使用GPS25-LVSOEM板（接收机）接收卫星信号，通过串口异步通信把数据传送给89C51单片机，单片机通过并口控制LED显示，从而实现GPS准确授时．同时，介绍了GPSOEM板输出的数据形式，并采用NMEA-0183格式中最常用的“$GPGGA”格式输出，由“$GPGGA”数据输出格式可编写出相关的接收程序．     

构建GPS监控系统的技术分析

交通运输工具的合理调度已经成为交通系统中的重要问题,以GPS、GIS和计算机通讯技术为基础的GPS监控系统能够有效解决这一问题。该文介绍了GPS监控系统的实现中的技术要点。