GNSS: A System of Systems - Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design

GNSS: A System of Systems

The first time I heard the term “system of systems” applied to GNSS, I thought to myself, “Yeah, a catchy phrase, but that won’t really happen.”

After all, much of the last 15 years has been spent accentuating the differences, divisions, and mutually exclusive competition among the existing and proposed GNSS systems.

The first time I heard the term “system of systems” applied to GNSS, I thought to myself, “Yeah, a catchy phrase, but that won’t really happen.”

After all, much of the last 15 years has been spent accentuating the differences, divisions, and mutually exclusive competition among the existing and proposed GNSS systems.

The Cold War legacy of suspicion between the United States and Russia, U.S. attempts to prevent the creation of Galileo, Europe’s initial proposal to overlay the GPS military code with a Public Regulated Service, Russia’s adherence to FDMA signals on center frequencies at a distance from other GNSS bands, the initial silence of China regarding its plans for Compass/ Beidou. . . .

. . . Not an optimal signal-to-noise ratio.

But I’m happy to admit that I may have been premature in my negative judgment.

Consider the 2004 U.S./European Union agreement on GPS and Galileo that has produced a common baseline modulation for future civil signals, the long-standing GPS/QZSS cooperation between Japan and the United States, pending agreements between the U.S. and Russia and between Russia and the European Union, and between India and Russia.

And probably the crowning achievement to date is the recent establishment of a Providers Forum by members of the International Committee on GNSS, a UN-nurtured group that provides a much-needed multilateral environment for discussion focused on compatibility and interoperability among GNSS systems.

The ICG meeting in Bangalore, India, drew more than 100 participants representing all the GNSS providers and delegates from international non-governmental organizations representing key user communities.

Why is this important? As the GNSS providers themselves observed in the report on their September 4 meeting India, “Multiple constellations broadcasting interoperable open signals will result in improved observed geometry, increasing end user accuracy everywhere and improving service availability in environments where satellite visibility is often obscured.”

Six current and prospective providers of GNSS systems and augmentations — the United States, Russia, European Union, China, Japan, and India — comprise the forum’s membership. They represent a diverse group of nations with powerful strategic interests, and distinct political and economic agendas.

So, the extent and specificity with which they laid down some fundamental principles at the ICG meeting were truly remarkable. (A report on that meeting on page 79 of this issue describes the points of agreement in greater detail.)

As Ken Hodgkins — a U.S. State Department official who cochaired the Providers Forum meeting — points out, moving beyond “individual statements from bilateral meetings” of GNSS providers takes the conversation to a new level.

The Bangalore statement reads like a wish list for a unified (if not necessarily unitary) Global Navigation Satellite System, lifting up:

• The need for “transparency” in the provision of open services and open, free commercial competition in receiver and applications markets.

• The intention of all systems to broadcast an open service using one or more signals provided to users free of direct user charges.

• Protection of radionavigation satellite system (RNSS) spectrum (a crucial point of unity as we approach the next meeting of the International Telecommunications Union’s World Radio Conference).

• The “essential” need for common center frequencies and the desirability of “commonality of other signal characteristics.”

• Cooperation regarding GNSS infrastructure (space and ground control/monitoring segments) which is desirable in order to permit open, free commercial competition in receiver and applications markets.

As such principles are realized through national, bilateral, and multilateral efforts, a true GNSS system of systems will emerge.

glen@insidegnss.com

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