Global Navigation Satellite Systems: Report of a Joint Workshop of the National Academy of Engineering and the Chinese Academy of Engineering

exchanges and cooperation, so as to improve the availability and stability of multi-GNSSs.
Compatibility and interoperability are beneficial to GNSS providers and receiver manufacturers and even more favorable to users. In order to strengthen compatibility and interoperability, multiple GNSS providers should explore having exchanges and cooperation, and implementing technical research together to explore all possible solutions to realize interoperability.
Interchangeability is a stronger and more specific goal than either compatibility or interoperability. It has already aroused multiple GNSS providers’ attention because it would enable GNSS users to estimate their longitude, latitude, altitude, and time offset based on any four satellites chosen from the interchangeable constellations. GNSS interchange ability is more a policy issue than simply a technical issue. Unswerving efforts should be made by multiple GNSS providers on GNSS interchangeability. This is especially important in regard to safety of life applications.
During the GNSS construction and development process, it is essential to establish a global performance monitoring and assessing system, aiming to continuously monitor systems, improve service reliability, and improve performances. Because different GNSS providers and resources from different regions worldwide are involved in this issue, enhancing international exchanges and cooperation is quite important to realize the objective.
GNSS space- and ground-based augmentation can effectively improve the performance of satellite navigation and positioning services. GNSS augmentation systems have to consider accuracy, continuity, availability, and integrity simultaneously. It is mutually beneficial for the BeiDou system and GPS system to enhance exchanges and cooperation between wide area augmentation systems.
The BeiDou system and GPS system share the common responsibility to resist illegal interference with satellite navigation systems, which is also shouldered by governments, industry entities, and users from all countries. Interference-free environments are also the goal pursued by all users. Technical discussions can be conducted regarding interference identification, detecting, and positioning issues, while interference resistant solutions can be explored from system design, terminal applications, and other broader aspects.
Certification of GNSS for use in aircraft landing has already taken place for GPS L1 signals in many parts of the world. However, it remains a very challenging enterprise. As new regions seek to certify the use of GNSS, it is essential to draw on the lessons learned from previous experiences. Prototyping and careful analysis of the results are important starting points. Experience with these prototype signals and the environ

Table of Contents

Front Matter R1-R16

Summary of the Workshop--As Reported by Grace Xingxin Gao 1-10

Address at the Opening Ceremony of the NAE-CAE Joint Workshop on Global Navigation Satellite Systems (GNSS)--Zhou Ji 11-12

Introductory Remarks--Charles M. Vest 13-14

WORKSHOP PRESENTATIONS 15-16

Development of the BeiDou Navigation Satellite System--Ran Chengqi 17-24

U.S. GPS Policy, Programs, and International Cooperation Activities--David A. Turner 25-34

Research Report on GNSS Interoperability--Lu Xiaochun, Lu Jun, Bai Yan, Han Tao, and Wang Xue 35-74

The Interchangeability Problem: Signals, Coordinate Frames, and Time--Rita M. Lollock, Thomas D. Powell, and Thomas A. Stansell 75-82

COMPASS/BeiDou Coordinate and Time Reference Systems--Yang Yuanxi, Tang Jing, and Han Chunhao 83-94

A Global Safety of Life Service from Multiple GNSS Constellations--Per Enge 95-104

Monitoring and Assessment of GNSS Open Services--Jiao Wenhai, Ding Qun, Li Jian-wen, Lu Xiaochun, and Feng Laiping 105-118

Alternative Position, Navigation, and Timing: The Need for Robust Radionavigation--Mitchell J. Narins, Leo V. Eldredge, Per Enge, Sherman C. Lo, Michael J. Harrison, and Randy Kenagy 119-136

Analysis of the GNSS Augmentation Technology Architecture--Chen Jinping 137-146

Impact of Intentional, Low Power, In-Band, Personal Privacy Devices (PPDs) on Aviation--A.J. Van Dierendonck 147-152

GNSS Open Signals Interference Issues and Countermeasures--Du Xiaodong, Wang Feixue, and Nie Junwei 153-166

Present and Future Applications of COMPASS Navigation Satellite System--Tan Shusen 167-178

Application of GNSS to Environmental Studies--Penina Axelrad 179-188

Recent Progress on GNSS Seismology--Liu Jingnan, Fang Rongxin, and Shi Chuang 189-198

Precision Agriculture: Opportunities and Challenges--Michael O'Connor 199-206

Integrity Lessons from the WAAS Integrity Performance Panel--Todd Walter, Per Enge, and Bruce DeCleene 207-228

Breaking the Ice: Navigation in the Arctic--Grace Xingxin Gao, Liang Heng, Todd Walter, and Per Enge 229-238

APPENDIXES 239-240

Workshop attendees [photo] 241-242

Appendix A: Workshop Agenda 243-246

Appendix B: Workshop Summary Record 247-250

Appendix C: Biographical Information 251-264

Appendix D: Acronyms 265-268