卫星定位技术与方法 2006-5-11
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Global Positioning System (GPS)
The NAVSTAR Global Positioning System (GPS) is a satellite-based radio-positioning and time-transfer system, designed, financed, deployed and operated by the US Department of Defense.
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Convergence on Final System 1973-1974
• SWITCHED CONCEPT TO 12-HOUR CIRCULAR ORBITS • 3 planes, 8 satellites each • i = 63° RETAINED DIRECT-SHIFT KEYED SPREAD SPECTRUM PN SEQUENCE DUAL FREQUENCY SIGNAL ON L-BAND PICKED INITIAL DEPLOYMENT OF 4+2 ‘BLOCK I” SATELLITES
Motto Adopted by the Joint Program Office on GPS Program
The mission of this Program is to: 1. Drop 5 bombs in the same hole, and 2. Build a cheap set that navigates (<$10,000), and don’t you forget it!
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DETAILS OF SIGNAL STRUCTURE & NAV MESSAGE DEFINED • C/A code designed with civil sector in mind • “P-Code” designed by Magnavox • Navigation message identical on both signals
However, the system has currently significantly larger number of civilian users as compared to the military users.
卫星定位技术与方法
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Global Positioning System (GPS)
卫星定位技术与方法 第一讲
课程概述
目标：介绍GPS卫星测量基本原理及其应用 PPT课件采用中英文结合方式 在学习制定教材的基础上，依据学生的兴趣和个 人能力，学习内容和形式多样 重点强调基本原理的理解和掌握 其它要求：网上查阅GPS专业资料的能力；英文 阅读能力；独立完成作业、严禁拷贝 成绩评定：平时成绩 30%；期末考试70%
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卫星定位技术与方法
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Managed Concept Debates 1969-1972
• EXPANDED TRANSIT • Insisted on worldwide overage • 153 satellites in 400 mile polar orbits • Transit carrier frequency
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Major Issues Identified in 1968 Studies
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CHOICE OF CARRIER FREQUENCY • L-Band • C-Band should be studied DESIGN OF SIGNAL STRUCTURE • Military and civilian use included ORBIT/CONSTELLATION SELECTION
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课程大纲
1. 2. 3. 4. 5. 6. 7. 8. 9.
历史、发展和当前状况 坐标系统与时间系统 卫星轨道运动 及GPS卫星的坐标计算 GPS卫星信号与传播 GPS观测量、观测方程及误差分析 绝对（单点）定位原理 相对（差分）定位原理 GPS测量实施及软件操作（实习） GPS应用
卫星定位技术与方法
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TRANSIT System
Researchers at Johns Hopkins observed Sputnik in 1957. Noted that the Doppler shift provided closest approach to earth. Developed a satellite system that achieved accurate positioning Called TRANSIT and provided basic ideas behind GPS
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PHASE I DESIGN 1974-1980
• BLOCK I SATELLITE CONTRACTS WITH ROCKWELL INTERNATIONAL • 6 satellites followed by 6 more • All satellite performance projections achieved. 3dB more transmitted power then required -13 • Exceptional (1x 10 ) on-orbit Rubidium clock performance achieved.
• The NAVSTAR Global Positioning System (GPS) program was initiated in 1973 through the combined efforts of the US Army, the US Navy, and the US Air Force. • The new system, designed as an all-weather, continuous, global radio-navigation system was developed to replace the old satellite navigation system, TRANSIT, which was not capable of providing continuous navigation data in real time on a global basis.
卫星定位技术与Biblioteka 法2006-5-1110
Development of Basic Navigation Satellite Concept 1964-1967
• • • SYSTEMATIC STUDY OF EVERY WILD IDEA IMAGINABLE CONVERGED ON “PSEUDORANGING” IN 1967 MAJOR STUDY CONTRACTS LET IN 1968 TO TUNE THE CONCEPT
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EXPANDED TIMATION • Initially only a Time Transfer System • Insisted on worldwide coverage • Expanded concept to intermediate altitude circular orbit constellation of 30 to 40 satellites
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References
Textbook
周忠谟, 易杰军, 周琪. GPS卫星测量原理与应用（修订本）. 北京: 测绘 出版社, 1997
References
刘基余. GPS卫星导航定位原理与方法. 北京: 科学出版社, 2003 刘大杰. 全球定位系统(GPS)的原理与数据处理. 上海:同济大学出版社, 1999 B. Hofmann-Wellenhof, H. Lichtenegger, and J. Collins, GPS Theory and Practice, Fifth edition. Springer-Verlag, Wein, New York, 2001. Alfred Leick. GPS Satellite Surveying, 3rd Edition. John Wiley & Sons, Inc., Hoboken, New Jersey, 2003. NAVSTAR Global Positioning System Surveying. US Army Corps of Engineers. EM 1110-1-1003
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GPS – Objectives 1/2
Suitable for all classes of platform: aircraft, ship, land-based and space (missiles and satellites), Able to handle a wide variety of dynamics, Real-time positioning, velocity and time determination capability to an appropriate accuracy, The positioning results were to be available on a single global geodetic datum, Highest accuracy to be restricted to a certain class of user, Resistant to jamming (intentional and unintentional), Redundancy provisions to ensure the survivability of the system,