Expert Advice - Progress Through Cooperation

April 1, 2007 By: Michael Shaw GPS World

Over the past decade and a half, the U.S. Global Positioning System has grown into a global utility providing space-based positioning, navigation, and timing (PNT) capabilities to a seemingly endless list of applications, from precision-guided farm machinery to child-finding devices that fit into sneakers. The dependable, consistent GPS system performance and the stable, predictable U.S. policy throughout this period have served as major contributors to this growth.

The United States remains committed as ever to GPS, to its continued evolution and future improvement. The United States is equally committed to working with other space-based PNT providers to promote GPS as a worldwide standard. We want to ensure future systems are compatible and interoperable with GPS for the benefit of users throughout the world. The path to the future leads through continued modernization of GPS coupled with cooperation with other nations.

The United States has already taken the first steps to modernize the GPS constellation and to improve its performance with the addition of new signals. The next generation of GPS satellites, featuring a second civilian signal for improved accuracy and reliability, began launching in 2005. Follow-on generations of satellites, offering even more capabilities, are already under development and will begin launching later next year. GPS modernization promises to bring multiple benefits to the user community, including improved accuracy, availability, integrity, reliability, robustness against interference, and interoperability with other systems.

By improving GPS and promoting it as a worldwide standard, we help generate economies of scale for our own domestic U.S. industries and for international manufacturers. For example, the United States openly publishes all of the technical information needed for anyone to build GPS equipment. In addition, broadcasting the GPS service to the world free of direct user fees has encouraged widespread adoption and use of this technology.

The U.S. government engages in a wide variety of activities to promote cooperation related to GPS and space-based PNT in worldwide GNSS both bilaterally and multilaterally through international bodies. The United States has worked closely with the United Nations Office of Outer Space Affairs to establish the International Committee on Global Navigation Satellite Systems, or ICG. The ICG is expected to serve as a sounding board for developing countries and user groups regarding space-based PNT systems and their applications. A draft work plan was developed in November 2006 during an ICG kick-off meeting in Vienna.

The draft ICG work plan includes efforts focused on identifying and eliminating sources of interference to GPS. It also includes organizing seminars throughout the world on a variety of GPS/space-based PNT topics such as spectrum protection and GPS use for sustainable development. Governments are reviewing the proposed work plan and will meet in Bangalore, India, in September 2007 to move forward with it.

The U.S. is also working within the ICG to establish a venue for current and future PNT service providers to promote common standards and discuss issues of mutual interest. Institutions such as the ICG are designed to encourage cooperation and to promote a long-term stable operating environment for space-based PNT services.

Before the establishment of the ICG, the United States was cooperating with the European Union (EU) and its member states. In 2004, the two parties signed a historic agreement establishing cooperation and a close partnership related to GPS and Europe's Galileo program.

A main goal of the U.S. / EU cooperation is to ensure GPS and Galileo are compatible and interoperable for the benefit of civil users around the world. The U.S. and the EU are designing GPS and Galileo to transmit one or more common civil signals, so future users will enjoy the benefits of multiple PNT satellite constellations. These benefits include increased satellite availability (particularly in urban environments) and improved resistance to satellite outages or terrestrial signal interference.

Both partners are committed to working together to encourage space-based PNT system providers to adopt the same common civil signals as GPS and Galileo to enhance worldwide user compatibility and interoperability. Working groups established under the U.S. / EU agreement have met to review items of mutual interest and to work to ensure the future continued availability of easily accessible, accurate, and reliable PNT systems and services for worldwide users.

U.S. and EU cooperation is also intended to maintain the level playing field in the rapidly growing global market for space-based PNT related business. The partners are working to ensure manufacturers around the world can build dual-system civil receivers capable of using GPS and Galileo through open standards. Users just want to know their receivers will work, regardless of provider. Both parties understand robust, market-based competition within the private sector has been the key to the success of GPS PNT technology.

The U.S. has also engaged in similar bilateral cooperation with Russia on its GLONASS system; with Japan on its Quasi-Zenith Satellite System (QZSS); and with India on its GPS and GEO-Augmented Navigation System (GAGAN).

The Future: 2007 and Beyond

Since the United States declared GPS fully operational in 1995, it has earned the confidence of millions of worldwide users. In the future, as GPS continues to evolve, other nations will add to the global space-based PNT system-of-system capabilities.

As the saying goes, "we live in interesting times" — and the future promises to be even more interesting within the worldwide PNT community. The next decade represents an era of great challenge and superb opportunity for all space-based PNT providers and users. It is imperative that nations work toward the complementary and interoperable nature of all these systems to ensure improved efficiency, safety, and security for PNT users throughout the world.