NAE-CAE Workshop on the
Global Navigation Satellite System
May 24–25, 2011
On May 24–25, 2011, the Chinese Academy of Engineering (hereinafter as CAE) and the U.S. National Academy of Engineering (hereinafter as NAE) held the NAE-CAE Workshop on Global Navigation Satellite Systems (GNSS) together in Shanghai, China. Mr. Wang Liheng, a member of CAE, emceed the opening ceremony of this workshop. Dr. Zhou Ji, President of CAE, and Dr. Charles M. Vest, President of NAE, attended this workshop and addressed opening remarks. The government delegates from both sides introduced the evolution process, current status, future development, applications, and international cooperation of the BeiDou Navigation Satellite system and the GPS system. In an atmosphere featuring openness, candor, and friendliness, experts and scholars conducted a frank exchange and extensive discussions on themes of GNSS compatibility and interoperability, system monitoring and service improvement, satellite navigation terminal and application technology, as well as talent exchanges.
The NAE-CAE Workshop on GNSS showed common concerns on following issues.
- Human beings are entering a new era, with many GNSS providers offering multiple Positioning, Navigation, and Timing (PNT) services. With the development and application of multi-GNSSs, users are able to enjoy more choices and better navigation satellite services with higher accuracy, reliability, and safety. GNSS providers should enhance
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1 Joint summary prepared at the workshop under the auspices of the CAE, reflecting the observations of the workshop participants.
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 interchangeability 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-
ments they operate in is critical to develop the threat models needed to support certification. An interoperability working group exists as a forum in which space-based augmentation systems service providers can exchange ideas and experiences.
- Satellite navigation terminals and application technologies are promoters for further development of the satellite navigation industry. Such development will be facilitated by public availability of Interface Configuration Documents for emerging GNSS systems and encouraged by private-sector engagement in receiver and application technologies. With the continuous development of GNSS application technologies, application terminals are upgrading day by day. GNSS application has gained much popularity and made significant contributions to science, engineering, and economic construction, as well as to our daily life, and is more and more indispensable for many industries. We can see a definite trend that there is still much space to improve GNSS for application technologies, and more application sectors are still waiting to be explored.
In conclusion, both sides have achieved basic identification of relevant technical issues. More mutually beneficial and fruitful exchange activities and cooperation will be conducted in the future. Both sides consider: (1) it is beneficial for technology advancement and construction of the BeiDou system and GPS system to strengthen technical exchanges and cooperation between CAE and NAE in the GNSS field; (2) it is valuable to enhance academic exchanges and mutual understanding between technical personnel on both sides to improve technologies together; and (3) such academic exchange activities shall be organized regularly or irregularly as needed.
The NAE-CAE Workshop on GNSS was held successfully in the spirit of mutual understanding and good will. Based on such an exchange platform, we hope to work together hand in hand and make further contributions to build up GNSS with higher accuracy, higher reliability, and more convenience for applications!
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