The Global Positioning System (GPS) is a satellite-based navigation system that was originally designed for the U.S. military. However, the number of civilian GPS users now exceeds the military users, and many commercial markets have emerged. This book identifies technical improvements that would enhance military, civilian, and commercial use of the GPS. Several technical improvements are recommended that could be made to enhance the overall system performance.

Table of Contents

Front Matter
Executive Summary
TASK 1
Recommendations that Enhance GPS Performance for Civil and Commercial Users
Recommendations that Enhance GPS Performance for All Users (Civil, Commercial, and Military)
Improvement Implementation Strategy
TASK 3
THE TASK
JOINT STUDY APPROACH
MAJOR ISSUES AND CONSIDERATIONS
GPS PROGRAM OVERVIEW
GPS TECHNICAL OVERVIEW
INTRODUCTION
GPS MILITARY APPLICATIONS
Current and Future Applications and Requirements
Accuracy and Integrity
Anti-Jam and Anti-Spoof Capability
GPS AVIATION APPLICATIONS
Current and Future Applications and Requirements
Resistance to Radio Frequency Interference
Operational Procedures
MARITIME USE OF GPS
Current and Future Applications and Requirements
Associated Technologies
Selective Availability
Findings
Current and Future Applications and Requirements
Accuracy Versus Other Requirements
Findings
Current and Future Applications and Requirements
Challenges to Full GPS Utilization
GPS EARTH SCIENCE APPLICATIONS
Oceanography
Airborne Geophysics
Accuracy Requirements
Oceanography
Findings
Current and Future Applications and Requirements
Time Synchronization
SPACECRAFT USES OF GPS
Orbit Determination
Launch and Re-entry Vehicle Guidance
Signal Visibility
SUMMARY
INTRODUCTION
Accuracy
SELECTIVE AVAILABILITY AND ANTI-SPOOFING
Selective Availability
Military Utility of SA
Impact of SA on GPS User Equipment Manufacturers and U.S. Competitiveness
Impact of SA on Civil Users
Findings and Recommendations
Impact of A-S on Military Users
Findings and Recommendations
SIGNAL STRUCTURE MODIFICATIONS TO REDUCE ATMOSPHERIC DELAY ERROR
Guidelines and Technical Considerations
New Signal Structure Options
Option 2: Narrow-Band L4 Signal
Increased Accuracy
Reduction of Receiver Noise and Multipath Errors
Findings and Recommendations
Recommended Upgrades to the Operational Control Segment
Accuracy Improvements
Overall System Improvements
Planned Block IIR Operation
Accuracy Improvements by Incorporating Satellite Ranging Data into Ground Solution
Ground-Based Integrity Improvements
Rapid, Direct Y-Code Acquisition
Inertial Aiding Improvements
Signal Processing Improvements
Improved L2 Ionospheric Correction
Possible Interim Operational Procedures
IMPROVEMENT IMPLEMENTATION STRATEGY
Use of a 24-Satellite Ensemble Clock
Reduced Satellite Clock Errors Through Use of Improved Clocks
Satellite-Based Integrity Monitoring
Cross-Correlation Type Y-Codeless Receivers
Y-Code Tracking PPS Receivers
Wide-Band Signals at High Frequency
Spot Beams
GPS Transmit Antenna Calibration
Improved L1 Signal Reception at Angles Below the Earth's Horizon
Appendix B Abbreviated Committee Biographies
ORIGINS AND DEVELOPMENT OF THE NAVSTAR GPS PROGRAM
Department of Defense
Department of Transportation
The Federal Radionavigation Plan
GPS TECHNICAL OVERVIEW
Space Segment
Operational Control Segment
User Equipment
GPS Signal Characteristics and Operational Concepts
Selective Availability and Other Positioning Errors
Atmospheric Error
Receiver Errors
Availability
Resistance to RF Interference
Differential GPS
Carrier Phase (Interferometric) GPS
Receiver Autonomous Integrity Monitoring (RAIM)
Combined Use of GPS and GLONASS
GPS and Loran-C
PERMANENT DIFFERENTIAL GPS AUGMENTATIONS
FAA Wide-Area and Local-Area DGPS Concepts
NOAA Continuously Operated Reference Stations
Maritime DGPS Services
Inmarsat
Racal Survey
ACCQPOINT
Differential Corrections Inc.
Appendix D Accuracy Definitions And Mathematical Relationships
Appendix E Report From Mr. Michael Dyment, Booz Allen & Hamilton
Appendix F Report From Dr. Young Lee, The MITRE Corporation
EFFECT OF ELIMINATING SELECTIVE AVAILABILITY (SA): IMPACT ON RAIM
Appendix G Increased Bandwidth Performance Analysis
Appendix H Signal Structure Options
OPTION 6
OPTION 9
Appendix I Report From Mr. Melvin Barmat, Jansky/Barmat Telecommunications, Inc.
Appendix J Selective Denial of Civilian GPS Signals by the Military
OLD TECHNOLOGY (100,000 GATE ASIC)
DISCUSSION
Appendix L Enhanced Signal Structures for the Military
SCENARIO 1: UNAIDED Y-CODE BANDWIDTH SIGNAL WITH A STANDARD ANTENNA
SCENARIO 5: AIDED WIDE BANDWIDTH STANDARD ANTENNA
SCENARIO 7: AIDED WIDE BANDWIDTH WITH NULLING AND BEAM-FORMING ANTENNA
Analysis
Analysis

The Global Positioning System - heftet, Engelsk, 1995