Journal of Global Positioning Systems (2004)
Vol. 3, No. 1-2: 12-15
GPS & Galileo: Prospects for Building the Next Generation of
Global Navigation Satellite Systems
Glen Gibbons, Jr.
Group Editorial Director and Association Publisher, GPS World, Advanstar Communications, Eugene, Oregon
Email: ggibbons@advanstar.com , Tel: 541-984-5286, Fax: 541-984-5333
Received: 15 Nov 2004 / Accepted: 3 Feb 2005
Abstract. In the next 5 to 10 years, the world will
experience the emergence of a true Global Navigation
Satellite System (GNSS) — a compatible and, in many
respects, interoperable system of systems. The U.S.
Global Positioning System, Europe’s Galileo, perhaps
Russia’s Glonass system, and regional augmentations
including the Wide Area Augmentation System (WAAS),
the European Geostationary Navigation Overlay Service
(EGNOS), radiobeacon-based systems such as the U.S.
Nationwide Differential GPS, and compatible
commercial differential correction services will comprise
this multifaceted GNSS. Common signal structures and
frequency plans will enable combined user equipment
that reduces the technical complexity and cost, while
vastly expanding related applications. Additional
satellites and signals, both more powerful and with
improved designs, will increase the availability of robust
signal reception outdoors and strengthen the potential of
indoor positioning using only GNSS user equipment. But
the path to the future is not without its risks: political,
technical, economic, and cultural.
Key words: GPS, Galileo, interoperability,
compatibility, GNSS.
One of the nice things about being a journalist is that
you’re not shackled to providing the same ratio of data to
opinions as scientists and researchers. As we listen to the
presentations over the next few days, I expect we’ll hear
about 10 to 100 statements of test results for every
conclusion offered by a speaker. Journalists, on the other
hand, can present large quantities of opinion only slightly
seasoned by facts and still be considered to have done
their jobs.
I’ll try not to abuse that latitude, however, as I take up the
subject of the prospects for building the next generation
of global navigation satellite systems.
After nearly a decade of distrust and bickering, Europe
and the United States are showing signs of real harmony
in the matter of global navigation satellite systems. Last
June, the two powers signed an agreement that lays the
foundation for substantive cooperation on GPS and
Galileo — not merely in system compatibility and
interoperability, but also in matters of trade and security.
In certain respects, one can imagine no more unlike
enterprises than the U.S. Global Positioning System and
Europe’s Galileo system. GPS is operated by the U.S.
military establishment as a public entity; Galileo will be
managed by a private consortium as a public-private
enterprise fully under civil control. GPS uses one time
standard; Galileo, another. The geodetic coordinate
frameworks are different. Not all the frequencies match
up and signal designs will vary. GPS is operated as a
national system; Galileo is multinational —
encompassing not merely the 25 nations joined in the
European Union, but also the People’s Republic of China,
Israel, India, and a half dozen or more other nations with
whom the EU has been talking. GPS delivers signals in
space for free; Galileo proposes to deliver certifiable,
guaranteed fee-based services in addition to a free open-
access signal.
And then, of course, there’s the most obvious difference:
GPS is a real, existing system with 29 satellites in orbit
and tens of millions of users around the world. Galileo is
a work in progress. Galileo is a developmental program
with a couple of billion euros in its pocket, some leased
channels on telecommunication satellites to support the
European Geostationary Navigation Overlay Service, a
bunch of components not yet assembled into the first
Galileo spacecraft (out of 30 planned for a full
constellation), and a patchwork of ground infrastructure.
Gibbons: GPS & Galileo: Prospects for Building the Next Generation of Global Navigation Satellite Systems 13
Galileo’s original completion date, originally planned for
2008, may slip until at least 2010.
Despite the substantial design differences, the two GNSS
systems are basically variations on a common
technological theme. Over the long run, the political,
institutional, and commercial realm is where
interoperability may meet its greatest challenge.
Technical experts will continually fine-tune frequency
plans and signal structures. Equipment manufacturers will
come up with ever-better products based on those
designs. Service providers and end users will apply them
in unpredictable and imaginative ways. But everywhere,
these efforts will be facilitated — or constrained — by
the business models, the rules adopted on intellectual
property rights, tax policies, security arrangements,
carriage requirements and regulatory policy, control and
management of the space and ground infrastructures,
international participation in the GNSS programs, and so
forth.
Ironically, GPS and Galileo have inhabited a looking-
glass world in which the two sides were sometimes as
divided by their similarities as they were united by their
differences. George Bernard Shaw once described
England and the United States as being two great nations
divided by a common language. After a few days in
Sydney, I’ve come to believe that we could probably
substitute Australia for England and the observation
would still be true.
But, in any case, the experience with dueling GNSSes has
demonstrated a similar principle of contrary dynamics.
Never were the two sides so far apart as when Europeans
first wanted to put themselves into the same GPS control
room as the Americans and, later, when they wanted to
put certain Galileo signals on some of the same
frequencies as certain GPS signals.
Back in the mid-1990s, a delegation of officials from
Brussels came to Washington, D.C., to discuss the idea of
European participation in the management and operation
of GPS. The Europeans said they’d even be willing to
help pay for the operation and modernization of the
American system.
The first thing the Americans asked was Who are you and
whom do you represent? The European Union? France?
Germany? Italy? Brussels? Our NATO allies? The
European Commission? The European Space Agency?
Who are we talking to? And the next thing the Americans
said was, we don’t need your money and we don’t want it
if it means we have to give up an iota of control over a
key national infrastructure. And besides, you haven’t
actually allocated any money for GNSS, no serious
money, anyway; just some study funds.
Well, the Europeans went off and set about answering
those questions and, in the meantime, came up with a
GNSS of their own — Galileo. Along the way, they also
created another practical example of how to go about
building a political union. Nothing sorts out the rhetoric
from the real stuff as having to build a tangible system
and service. After the Airbus project and implementation
of the euro currency, Galileo already stands as a notable
example of successful common effort by the European
Union. At least, so far.
Anyway, after a few years, the European Commission
came back to the United States once again and said, okay,
let’s talk about GNSS now. And, because the EU
appeared to have its diplomatic act together, the United
States set up an interagency working group, led by the
State Department, to meet with the Europeans.
Nonetheless, for the next couple of years, the two sides
seemed to be talking past each other: the Europeans
wanted to talk about specific details of the technical
designs of the systems. The United States insisted on
discussing more general matters such as trade policy and
regulatory issues first. This went on until two things
happened: first, the EU made a firm commitment of
funding to build Galileo. And, second, the Europeans
went ahead and came up with a provisional design on
their own. Now, what got the United States’ attention was
a part of the proposed Galileo design that overlaid the
publicly regulated service (PRS), an encrypted security-
oriented signal, on top of part of the new GPS military
signal (M-code) planned for the L1 band.
Once again, a seeming common ground — use of the
same radio frequency — became a point of contention.
U.S. defense officials argued strongly that the PRS
overlay would undermine GPS operators’ ability to jam
non-military signals in a theater of operations without
interfering with the M-code. At that point, the two sides
began talking about all of the issues at once. They set up
technical working groups – which sometimes met under
secret classified conditions -- to come up with mutually
workable solutions. The United States even went so far as
to propose that GPS would use a similar signal structure
as Galileo — the binary offset carrier (BOC) — if the EU
would agree to a narrower frequency plan that moved the
PRS away from the M-code.
Now, the technical compatibility and interoperability of
these two GNSSes for which the initial U.S.-EU
agreement has laid the foundation will definitely bring
GPS and Galileo closer together. On the other hand, the
differences between the two complementary systems will
tend to bring the GNSS world closer together. By
complementary, I mean the two systems are similar
enough to be compatible, but different enough to be
useful. Separate GPS and Galileo signals, separate ground
and space infrastructures, separate operating entities, and
separate budgets. These things will build the global
GNSS marketplace and user community faster than one
system alone. That will occur as a result of the increased
redundancy, signal availability, robustness, and
14 Journal of Global Positioning Systems
ultimately, user confidence that result from having
compatible but independent systems.
Not only will they be complementary systems, but they
will be two primary systems – that is, each on its own
will be capable of providing a complete positioning and
timing service. This simple and seemingly self-evident
concept has not fully taken root yet. A few years ago,
about the time the European system was designated
Galileo, I was moderating a GNSS panel at a conference
in Toulouse, France – a centers of the European space
industry. An official from EADS, one of the leading
European defense and aerospace companies, made the
observation, “It will be desirable to have a back-up
GNSS.” And I said, “Yes, GPS as a back-up to Galileo,
right?” And the EADS official looked at me quite
blankly, because he had meant the opposite. At the time,
part of the argument for building Galileo was that it
would provide a back-up for GPS in case the U.S. system
experienced a failure. That rationale and the fact that GPS
came first and had been an operational system for many
years has created the sense of its primacy – even among
public and private advocates for Galileo. That unspoken
attitude still persists in some quarters, and probably will
persist until an operational Galileo system has achieved
true parity – or even a superior position – with GPS. At
which point, either system will serve as a back-up – as
well as a complement -- for the other.
In addition to these benefits, Galileo will help keep the
United States honest in its management of GPS. Not that
I think the U.S. government has been noticeably
dishonest or narrowly manipulative in this matter. Quite
the contrary, the United States has been remarkably open-
handed in ensuring access to GPS by users around the
world. In fact, the rapid adoption and spread of GPS
technology and applications could not possibly have
taken place the way it did without that policy. And it is a
precedent that I believe Galileo’s leaders would benefit
from considering further.
Over the years, the United States has been criticized for
many things regarding its GPS policies and management.
But one thing that it did get right – perhaps in large part
accidentally and almost unwittingly – was to make the
civil signal open and free to users around the world.
Nonetheless, unilateral control, like unilateral policy-
making, of such a potent global utility is an invitation to
complacence and unresponsiveness by the system
operator. Monopolies also tend to pose threats to
technological innovation and economic progress.
To this end, the mere discussion of a European system
has already benefited GNSS users, and Galileo’s
implementation will extend those benefits. I believe the
prospect of Galileo contributed to the urgency to craft the
first comprehensive U.S. presidential policy on GPS in
1996, to eliminate selective availability in May 2000, and
to modernize the Block IIR generation of satellites. I
believe that approval of Galileo’s implementation by the
European heads of state and authorization of public
funding will help keep GPS modernization, including the
GPS III program, on track. Completion of Galileo within
the near term will definitely accelerate growth in GNSS
product and service markets, as well as drive new
applications. It could also encourage the United States to
change its launch policy from launch-on-need, that is,
replacing satellites only as they fail. That means that
many critical innovations in GPS signal and system
design have to wait until after launch of all the unused
satellites with technology that has been outstripped by
technical advances. Successful completion of a Galileo
constellation with new signals and higher power could
encourage GPS’ managers to launch on a planned
schedule to more quickly install a new operational
capability with the modernized GPS signals and satellites.
So, all this comes as good news for GNSS equipment
manufacturers and users around the world. But many
objectives must still be achieved and many obstacles,
avoided, before compatible, interoperable GNSS becomes
a reality. An example of the kinds of things that can
derail this process can be seen in a recent article in a
British newspaper. The article described an exchange
between U.S. and European officials attending a
conference on military space relations that led to one U.S.
delegate suggesting that the United States would attack
Galileo satellites if they continued transmitting signals
that might be used by adversaries in a theater of conflict.
Now, I would not invest this anecdote with too much
weight or power – even if it is completely true, even if
these comments were actually made. I believe that they
represent more an expression of anxiety than of intention.
Indeed, I think that we should all share the anxiety of
misuse of GNSS, whether GPS or Galileo. But, as I
understand the NAVWAR scenarios, capabilities, and
solutions developed by the U.S. Defense Department, the
primary means to prevent hostile use of GNSS will be
much more benign, limited in scope and targeted against
the perpetrators and not GNSS system operators. And
between any GNSS-related crisis and an assault on
Galileo satellites or infrastructure stands the agreement
signed in June, which established the official channel for
relations between the European Union and the United
States in GNSS matters.
So, what are some of the things that need to be done to
continue the auspicious beginning on GPS and Galileo
cooperation? Well, here a few suggestions:
** Establishing a permanent mechanism for regular
political consultations on the GNSS agenda, which must
inevitably evolve as the systems mature and modernize.
** Cooperation in system operations and open formal
lines of communications, 24/7, between GPS and Galileo
Gibbons: GPS & Galileo: Prospects for Building the Next Generation of Global Navigation Satellite Systems 15
controllers — whether that’s a black box or a red
telephone, or even an exchange of liaison officers in
master control stations.
** A further agreement on security-related matters that
sketches out the appropriate actions for possible threat
scenarios. That could even include creation of a joint
security board for assessing threats against either system,
evaluating situations that might require jamming or
degradation of civil signals, and recommending
appropriate courses of action. Of course, actual events
rarely take the exact form or follow the exact course
anticipated by contingency plans. But forward-looking
conventions would increase the state of readiness, the
famikliarity of GNSS olperators and officials with their
counterparts, and the capacity for responding to threat
situations in whatever form they may arise.
** Clear statements on the reciprocal role that industrial
partners from the United States and Europe can have in
building and operating the other’s GNSS. The Boeing
Company has included Alenia Spazio and Alcatel Space
on its GPS III team, EADS-Astrium is working with
Boeing in GPS/Galileo matters, and the iNavsat
consortium has done the same with Lockheed Martin,
SiRF Technology, and NavTeq in its efforts to secure the
Galileo concession.
But more needs to be done. The Galileo Joint
Undertaking, the Galileo Supervisory Authority, or, if
necessary, the European Council of Transport Ministers
should provide a clear statement on status, ownership,
and access to the Galileo equivalent of the GPS Interface
Control Document (ICD). The GPS ICD provides
complete technical specifications that enable
manufacturers to build GPS equipment.
The two sides should also clarify the rules for U.S.
companies’ participation in building, maintaining, and
operating Galileo. At the same time, the United States
should clarify its guidelines on the export of GNSS-
related technologies and the allowable scope for
European industrial participation in the GPS III program.
** Agreements on carriage requirements for airplanes and
commercial vessels that minimize the financial burdens
on the transport companies and maximizes the use of
combined GPS/Galileo equipment.
In closing, I’d like to end with a small warning. You
often hear people say that the uses of GPS are limited
only by the human imagination. I’ve used the expression
myself. It has a wonderful gee-whiz quality to it --
Limited only by the human imagination. And with a
second, interoperable GNSS, I guess that what? the
human imagination will get twice as big, or GNSS
innovations will take place twice as fast, or something
like that?
But I had an experience a few days ago that has led me to
think about that idea a little more closely: When I arrived
in Sydney on Saturday morning, I went down to the
Royal Botanical Gardens to try to walk off some of my
jet lag. One of the many amazing facts that I learned there
is that the world contains 80,000 species of edible plants.
However, only 20 species make up 90 percent of the food
actually eaten by the world’s population – things like
corn, wheat, and rice. So, before we start feeling too
smug about the prospects of GNSS, and assuming that a
second system is going to make things twice as good, I
think we need to recall our track record with the human
diet. Only implementing 20 out 80,000 options isn’t so
hot, and we need to do better with GNSS. And that will
take not merely imagination, but hard work, good
intentions, and sustained effort.