Overview of the Global Positioning System (GPS)文档.pdf
文本预览下载声明
An Overview of the
Global Positioning System
(GPS)
Ken Campbell
Report prepared for ENDEV Project, Sri Lanka
February 1997
Environmental Sciences Department
Natural Resources Institute
Chatham Maritime
ME4 4TB
U.K.
Contents
1. Introduction 3
1.1 GPS and Earlier Electronic Navigation Systems 3
2. GPS Positioning 4
2.1 Space Segment 4
2.2 Control Segment 6
2.3 User Segment 6
2.4 Precise Positioning System (PPS) 6
2.5 Standard Positioning System (SPS) 6
2.6 GPS Satellite Signals 7
2.6.1 GPS Navigation Message 7
2.7 Pseudo-Range Navigation 8
2.8 Sources of Error in GPS position fixes 11
2.8.1 Selective Availability 12
2.8.2 Geometric Dilution of Precision (GDOP) 13
2.8.3 A Practical Demonstration of Error: How good is a single position fix? 13
2.9 Differential GPS (DGPS) Techniques 14
2.9.1 What is DGPS ? 15
2.9.2 DGPS in Practice 15
2.9.3 Sources of Reference Station GPS Data 15
2.9.4 Postprocessed DGPS 16
2.9.5 How Accurate is DGPS? 16
2.9.6 Receivers 17
2.10 Future Development of the civilian GPS system 18
3. Projections, CO-ORDINATE Systems and Datums 19
3.1 Datums 19
3.2 Co-ordinate Systems 21
3.3 Projections 22
4. Glossary 25
5. Bibl
显示全部