文档介绍：本科毕业论文
外文文献及译文
文献、资料题目:Global Positioning System
文献、资料来源:
http://en./wiki/Global_Positioning_System
文献、资料发表(出版)日期:
院(部): 土木工程学院
专业: 土木工程
班级: 测绘052
姓名: 唐海国
学号: 2005011047
指导教师: 郭秋英
翻译日期:
外文文献:
Global Positioning System
The Global Positioning System (GPS) is a global navigation satellite system (GNSS) developed by the United States Department of Defense and managed by the United States Air Force 50th Space Wing. It is the only fully functional GNSS in the world, can be used freely, and is often used by civilians for navigation purposes. The Global Positioning System (GPS) is a satellite-based navigation system made up of work of 24 satellites placed into orbit by the . Department of Defense. GPS was originally intended for military applications, but in the 1980s, the government made the system available for civilian use. GPS works in any weather conditions, anywhere in the world, 24 hours a day. There are no subscription fees or setup charges to use uses a constellation of between 24 and 32 medium Earth orbit satellites that transmit precise radiowave signals, which allow GPS receivers to determine their current location, the time, and their velocity. Its official name is NAVSTAR GPS. Although NAVSTAR is not an acronym,[1] a few backronyms have been created for it became fully operational in 1993, GPS has e a widely used aid to navigation worldwide, and a useful tool for map-making, land surveying, commerce, scientific uses, and hobbies such as geocaching. Also, the precise time reference is used in many applications including the scientific study of earthquakes and as a required time synchronization method for work protocols such as the IS-95 standard for CDMA. GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. GPS receivers take this information and use triangulation to calculate the user's exact location. Essentially, the GPS pares the time a signal was