点击下载ppt格式 - 地理信息系统GIS精品课程- 浙江水利水电专科学校.pptVIP

* * * * * * * * * Figure 2.15 The shaded survey township has the designation of T1S, R2E. T1S means that the survey township is south of the base line by one unit. R2E means that the survey township is east of the Boise (principal) meridian by 2 units. Each survey township is divided into 36 sections. Each section measures 1 mile by 1 mile and has a numeric designation. * 2.5 Working with Coordinate Systems in GIS  在GIS中使用坐标系统 Precisely establishing location 准确建立位置 Registration 注册 2.5.1 Projection File 投影文件 2.5.2 Predefined Coordinate Systems 预定义坐标系统 2.5.3 On-the-Fly Projection 快速投影 * 2.5.1 Projection File 投影文件 Text file that stores information on the coordinate system on which the data set is based 储存数据所依据的坐标系统信息的文本 * 2.5.2 Predefined Coordinate Systems 预定义坐标系统 GIS package groups coordinate systems into predefined and custom GIS 软件包把坐标系统分为预定义的和自定义的 Predefined means that parameter values are known and already coded into the GIS package 预定义是指参数取值是已知的，并编码到GIS软件包 * 2.5.3 On-the-Fly Projection 快速投影 Designed for displaying data sets based on different coordinate systems 为显示基于不同坐标系统的数据集而设计 Automatically converts data sets to a common coordinate system 自动将数据集转换成共同的坐标系统 实质上是两个平面场之间点的坐标变换（基于两种地图投影点坐标的关系式） * * * * * * * * * * * * * * * * * * * * * * * * * * * * Chapter 2 Coordinate Systems 坐 标 系 统 浙江水利水电专科学校 PowerPoint by 僧德文 Copyright ? The McGraw Hill Companies, Inc. Permission required for reproduction or display. * CHAPTER 2:Coordinate Systems 坐标系统 Chapter Outline 概要 2.1 Geographic Coordinate System 地理坐标系统 2.2 Map Projections 地图投影 2.3 Commonly Used Map Projections 常用地图投影 2.4 Projected Coordinate Systems 投影坐标系统 2.5 Working with Coordinate Systems in GIS 在GIS中使用坐标系统 * Basic Principle基本原理 Map layers must align spatially 地图必须以空间排列 Concept of registration 注册的概念 * Figure 2.1 The top map shows the road networks in Idaho and Montana based on different coordinate systems. The bott