1、 毕 业 设 计（论 文） 外 文 参 考 资 料 及 译 文 译文题目： Introduction to the Global Positioning System 全球定位系统的介绍 学生姓名： 学 号： 专 业： 通信工程 所在学院： 指导教师： 职 称： 201x 年 xx 月 xx 日 Introduction to the Global Positioning System -From “Corvallis Microtechnology, Inc. 1996” Chapter One: What is GPS? The Global Positioning System (GPS
2、) is a location system based on a constellation of about 24 satellites orbiting the earth at altitudes of approximately 11,000 miles. GPS was developed by the United States Department of Defense (DOD), for its tremendous application as a military locating utility. The DODs investment in GPS is immen
3、se. Billions and billions of dollars have been invested in creating this technology for military uses. However, over the past several years, GPS has proven to be a useful tool in non-military mapping applications as well. GPS satellites are orbited high enough to avoid the problems associated with l
4、and based systems, yet can provide accurate positioning 24 hours a day, anywhere in the world. Uncorrected positions determined from GPS satellite signals produce accuracies in the range of 50 to 100 meters. When using a technique called differential correction, users can get positions accurate to w
5、ithin 5 meters or less. Today, many industries are leveraging off the DODs massive undertaking. As GPS units are becoming smaller and less expensive, there are an expanding number of applications for GPS. In transportation applications, GPS assists pilots and drivers in pinpointing their locations a
6、nd avoiding collisions. Farmers can use GPS to guide equipment and control accurate distribution of fertilizers and other chemicals. Also，GPS is used for providing accurate locations and as a navigation tool for hikers, hunters and boaters. Many would argue that GPS has found its greatest utility in
7、 the field of Geographic Information Systems (GIS). With some consideration for error, GPS can provide any point on earth with a unique address (its precise location). A GIS is basically a descriptive database of the earth (or a specific part of the earth). GPS tells you that you are at point X,Y,Z while GIS tells you that X,Y,Z is an oak tree, or a spot in a
