Re: Lockheed Martin Delivers First Modernized GPS Satellite to U.S. Air Force for May Launch
From: Sam Wormley (swormley1_at_mchsi.com)
Date: 02/15/05
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Date: Tue, 15 Feb 2005 04:52:20 GMT
mx125 wrote:
> I second that question . . .does anyone have any insight into the
> benefits??
>
Ref: http://www.ion.org/newsletter/v13n1.html#feature3
The Quarterly Newsletter of the Institute of Navigation
Volume 13, No. 1 -- Spring 2003
GLONASS, GPS and Galileo: Present and Future Aspects
By Mr. Leeke van der Poel, Hydro International
Editor's note: Mr. Leeke van der Poel, editor in chief of Hydro
International, a well-known journal published by GITC bv, a
Nether-lands company, posed the following questions to several
professionals in the field. The responses with graphics were provided
by three of the experts selected by Mr. van der Poel and were orginally
published in the April 2003 issue of Hydro International. The interview
as it appears here has been edited slightly for publicaion in the ION
Newsletter. The ION thanks GITC bv for its permission to reprint the
interview.
Global Navigation and Hydrography is the theme of this issue. GALILEO
has received a "green light", GPS has planned some important
improvements and GLONASS has entered a significant development program.
It is time for Hydro International to ask experts of each GNSS to give
their opinion on certain topics and to address the question: "What is
in it for us surveyors?" The experts we interviewed are: Dr. Vidal
Ashkenazi (GALILEO), Mr. Keith McDonald (GPS) and Dr. Boris
Shebshaevich (GLONASS).
The planned GALILEO-system involves some discussions with the already
present GNSS elements and some of our questions have a political
aspect. Dr. Ashkenazi preferred therefore to give a view on our
questions that we publish under the last question.
Question: Are you concerned that the different GNSS system elements are
competing in a political, technical and economic sense? If so, what
consequences to quality and availability of services to the user
community do you observe or foresee?
Shebshaevich: Generally speaking, competition is an inevitable aspect
of any human activity. GNSS activities are not excluded. Actually, GPS
and GLONASS appeared initially as elements of national security. Both
were strongly stimulated by political and technical competition of the
1970's and 80's.
The economic aspect emerged later (in the 1990's) when both GNSS system
elements became operational and their civil capabilities were declared
available free of charge to the world community. Economic reasons
provide a serious guarantee of the quality and availability of services
now. Of course, there are certain negative consequences of competition
but they are the same as for any other international business and will
be minimised by the same juridical instruments.
McDonald: The various navigation satellite systems are in many ways
competing but in my view this is not a real concern. All systems need
to justify their existence to their respective backers but there are
significant benefits from the competition. The systems will work
together to serve the users.
The availability of several systems provides substantially improved
capabilities such that there is an enhanced value for each of the
systems. An example of this is shown in Table 1 that compares the
capabilities of GPS and GALILEO by themselves and in combination. There
are advantages evident in accuracy, integrity, availability and
coverage. It is important that the system sponsors don't detract from
this by attempting to establish unreasonable restrictions or monopolies
on their system's use.
Also, the experience of GPS (see Fig. 1 for representative spacecraft)
indicates that there is an economic stimulus associated with the
navigation satellite technology and equipment area that encourages
others to proceed with alternative navigation satellite systems. The
navsat field is a growth industry!
Two important factors that may thwart the development of certain
capabilities of these systems are first, the several billion dollar
cost associated with the implementation of a navsat system; and second,
the system provider's concerns (including again, cost) and their
efforts to deny the use of available systems to adversaries during
times of hostilities.
However, there are no plans to cease transmitting the GPS signals.
Also, there is strong interest and a commitment to maintaining GPS
capabilities for all users outside the area of hostilities. This
implies some secure provisions (e.g., encryption) or other safeguards
for all or a portion of the military signal structure. This is, in
general, not a concern for hydrographic users.
Question: GPS is available as an operational system to civil users.
Consequently, it emerged into a major success for the (US) industry and
the user community has become addicted to GPS. As a trade-off, there is
no guarantee that user access remains unrestricted in the event of (US)
national security or defense concerns. This might greatly harm friend
and foe economically and security wise. Do you think that a guarantee
to the International civil community should be given that at least in
case of severe danger to lives, a basic GNSS signal should be
guaranteed, or is there a national or regional responsibility for
back-up -facilities?
Shebshaevich: Juridical guaranties for all and unconditional system
availability are not realistic at the present time for many reasons.
The process of particular agreements is more practical.
The Russian contribution to GNSS is GLONASS. The adopted governmental
plans consider international cooperation to be one of the basic
principles of its development and employment.
The September 11, 2001 events initiated investigations for additional
back-up facilities. Ground based long range navigation systems like
LORAN-C are among potential candidates. Russia has its own system of
this type - CHAYKA. Its European, Northern and Far East transmitting
station networks cover East Europe, Arctic and the Far East regions of
Russia.
McDonald: Guarantees have been made by both the governments of the US
and the Russian Federation for access to GPS and GLONASS. These
occurred in 1985 at a meeting of the International Civil Aviation
Organization (ICAO), an arm of the United Nations, in which both states
committed to provide free access to their civil signals for ten years
and an indefinite period beyond this. Further, the US government
committed to informing the international community six years prior to
any planned degradation of GPS civil (aviation) service. This
commitment has the strength of an international treaty, and there has
never been any interest to my knowledge in modifying this -commitment.
Of course, war conditions can change the character of any arrangements.
However, the US has always guaranteed unrestricted access to its GPS
civil signals (now the C/A-codes on L1) and has no plans to discontinue
it. In fact, these signals are required in many cases to acquire the
military (P/Y) signal. Also, access to the augmentations to GPS is open
and available to all properly equipped users.
As a member of the US National Academy of Science Committee on The
Future of GPS that studied the access and many other issues of GPS, two
things among others became clear:
1.The use of Selective Availability (SA) to degrade the performance of
GPS is not a sensible or viable way to deny access of GPS civil
signals to adversaries. SA was reduced to zero on May 1, 2000, and
there are no plans to change this. 2.There is consensus that the
appropriate way for the military to control GPS operations in times of
hostilities is to develop techniques that first, deny the signal to
adversaries in a region of operations, and second, accomplish this
without adversely affecting civil uses in adjoining areas. A
substantial program to provide this capability is in -progress.
So, in summary, the current GPS civil signals will be available
indefinitely without degradation. Additional civil signals (unrelated
to any military use) are planned for the future at L2 (1227.6 MHz) and
a pair of more capable signals are to be placed at a lower L5 frequency
(1176.45 MHz). Figure 2 shows the civil and military signal evolution
for GPS.
Question: GNSS systems have an important function not only in
navigation and positioning but also in (industrial) timing and
synchronization. There is little awareness of the increasing dependency
of our society to this "by-product." When GNSS timing signals are
distorted or absent we might be faced with serious problems in
communications, data networks (e.g. electronic financial transactions),
distribution of energy, remote control, etc. Do you consider this issue
subject to international, national or institutional concern?
Shebshaevich: GNSS-techniques and applications are penetrating all
areas. It makes no sense to stop this process. The only sensible plan
is to minimise the risks and here, all possible coordination and
agreements should be involved at international, national and
institutional levels.
For example, the Russian Ministry of Telecommunication decree of 1999
prescribes the use of dual system GLONASS/GPS receivers for Russian
telecommunication networks synchronisation. Photo 1 illustrates the
RIRT's product set for this application including a 16-channel
GLONASS/GPS OEM-board and smart clocks controlled by GNSS signals.
These clocks are capable of keeping time in a holdover mode when
satellite visibility is limited.
The Ministry of Transport considers similar safety measures for
Autonomous Identification System (AIS) transponders. One can imagine
the national regulations of this kind for critical applications.
McDonald: In my view, there has been considerable international,
national, and institutional concern in this area for many years. The
international timing community has defined standards, techniques and
practices that have generally been adopted.
Many US power grids, cell phone systems and data networks are
synchronized by GPS and have been for some time. The systems whose
infrastructures are linked to GPS time typically have backup mechanisms
such as very stable quartz or atomic standard clocks that can provide
reliable operation for an extended period following any GPS timing
failure.
Question: WRC1 2003 will allocate spectrum to GNSS. Do you think that
the international GNSS community has sufficient power to claim the
various frequencies to provide bandwidth for the different proposed
system (extensions)? Economic preference for spectrum use consistently
appears to go to satellite communications and the various communication
services. Is there consensus to divide the allocated spectrum over the
different GNSS systems in the most efficient way?
Shebshaevich: Satellite navigation and satellite communication are of
equal importance. As a result, the existing systems are continuously
improved in the frames of allocated frequency bands.
The current spectrum allocation provides rather non-conflicting
coexistence of satellite navigation and communication systems. By the
way, to reach electromagnetic compatibility with satellite
communication systems, GLONASS frequencies are being shifted.
Future satellite systems will integrate both navigation and
telecommunication functions in one and it will be the most efficient
solution from all points of view.
But any attempt to violate the "status quo" in the nearest future is
not reasonable, to my mind.
McDonald: There is a problem in that traditionally communications
services appear to take some priority over navigation services because
of the relative economics involved. However, WRC 2000 held in Budapest
provided substantial spectrum for both US and European systems such
that additional requirements appear to me to be modest. Figure 4
illustrates the specific ITU radionavigation frequency assignments
relating to GNSS services.
As far as a consensus to divide the spectrum in the most efficient way,
it is seldom that international bodies select the most efficient way.
They normally are quite good however, at providing an acceptable
solution that is workable to the parties involved. Obtaining consensus
can be difficult and at times isn't possible, mainly because of
political pressures.
Question: A solution to many issues is a well-defined interoperability
and ultimately merging/integration of the three global systems. Is
there a political will and has the technical feasibility been
examined?
Shebshaevich: It must be agreed that a universal international
satellite navigation system is a perfect solution. To move in this
direction many non-technical problems must be solved. The level of
cooperation in this field is still not sufficient to say it is feasible
just now. But nevertheless, we shall move step by step. It is much
easier to integrate GPS, GLONASS and GALILEO in user equipment. And it
is what we are doing now and shall continue to do.
McDonald: The technical feasibility of integrating user equipment for
operation with all systems has been examined and does not appear to be
a significant problem. However, the political will to provide
well-defined interoperability specifications does not appear uniformly
strong. Interoperability will probably first occur in the marketplace.
Clever engineering will provide receivers that are interoperable and
will meet the market demands of the user community.
Question: Public Private Partnership (PPP) is a means to spare the
taxpayer and involve private enterprises in building the system,
providing services and supporting the maintenance and upgrading
processes. However, when an activity is not profitable, the continuity
and quality of the system might be at stake. Do you believe that
governments may be forced to take over those activities from industry
which are indispensable to the public?
Shebshaevich: The GLONASS development program for the next ten years
makes economic efficiency the corner stone for the employment of
GLONASS. The program financing implies federal and state budget
components and off budget investments too. Funding of the most critical
system segments are mainly the responsibility of governmental bodies.
The responsibility for user equipment and augmentation systems
development as well as service providing can be non-state
responsibilities to a considerable extent. Many applications, for
example natural resource exploitation, land cadastre management and
vehicle tracking are attractive enough for business at the local and
private level.
McDonald: Many have had concerns about the workability or viability of
the PPP arrangement planned for the GALILEO development if it places a
significant burden on the industry participants. It appears that a PPP
can be successful and desirable if the states involved are willing to
take over the lion's share of the funding, the management of the
economic arrangements and monitor how the private business develops.
The private partners' involvement and success may be strongly
determined by the public sector's economic and management commitment.
This can be problematic. It therefore, seems to me that the governments
involved will have to show leadership in providing the major part of
the funding and a commitment to the success of a PPP arrangement.
Question: Inmarsat started as an Institution financially supported by
-member states and a stakeholder acting on behalf of the US. Inmarsat
has been transformed into a private organization which is not dependant
on financial support by governments. Do you think that GNSS could go
the same way?
McDonald: No, in my opinion GNSS cannot go the same way. The financial
arrangements for Inmarsat have been successful partly because they
involve a product that can literally be sold by the bit (or byte) to
end users who are easily identified (and billed). Navigation/position
determination/time services differ in that they normally involve a
multi-satellite one-way transmission to unknown passive users. These
costs are typically the responsibility of, and are paid for by, user
organizations or states. Public service and other encryption techniques
may possibly make this practical in the future.
In general, government agencies provide safety related navigation
services. Augmentation services that are primarily of a communications
nature (e.g., downlinks of differential data) can be and currently are
provided by a number of service providers on a fee basis.
Question: Defense agencies, holders of intellectual property rights and
patents might object to interoperability or merging of systems for
different reasons. For the sake of safety of navigation, however, a
basic service level globally should be guaranteed by the operator(s)
under all circumstances. This basic civil service level should be fully
operationally capable (FOC). All additional levels of service could
become available on a commercial basis as long as it does not interfere
with the defined public tasks to facilitate Safety of Life (SOL)
Navigation and Search and Rescue (SAR) activities. WAAS, LAAS, RTK and
other (additional) services could be made available by local
authorities or (private) concessionaires, consistent with the GNSS
operating regulations. What is your comment?
McDonald: The services could be made available to local authorities and
concessionaires in some circumstances, but it does not generally appear
necessary. The services indicated provide a revenue stream to the
governments involved through the tax base of this growth industry.
Governments are equipped and can be motivated to support GNSS
technology developments much as they support other developments of
benefit to their industries and citizens.
Question: Nautical and Aeronautical Charts are published for worldwide
application. It is of major importance that users can rely on globally
standardized geodetic and geographical references. For GPS, the
reference system is WGS84 which is continuously maintained and
periodically updated. Tracking information is available and contributes
to the ITRS (International Terrestrial Reference System). GLONASS and
GALILEO are also using terrestrial tracking stations which are tied in
to ITRS. Despite this commonality GLONASS and GALILEO use their own
reference systems, which differ slightly from WGS 84. Also there is no
satellite clock synchronization between the 3 systems. Standardization
between the GNSS systems would make the individual system more robust
and would economize on costs and efforts. Is global co-operation and
standardization considered and by whom?
Shebshaevich: Systems of national standards and the certification of
system developments are important activities in the GLONASS development
program. Harmonisation of national and international requirements is
one of the tasks. The necessity for co-operation with international
co-ordination bodies is evident.
Meanwhile, modernised GLONASS space craft (S/C) will transmit messages
containing GLONASS-GPS time reference discrepancy. Naturally our
GLONASS/GPS user equipment operates with both geodetic reference
systems. Proper transformations do not introduce noticeable errors.
McDonald: Standardization is normally desirable. However, there is some
question as to whether or not inter-system standardization would make
the individual systems more robust or economize on costs or efforts. It
would make multiple systems easier to work with in combination, but the
costs and efforts to maintain an acceptable infrastructure for
accomplishing the inter-system standardization and synchronization
could be significant. However, this may not be a significant concern.
The WGS-84 reference frame for GPS is now nearly identical to the ITRF
(to the cm level) and the computation of WGS-84 fundamental coordinates
is accomplished using a number of stations also employed in ITRF
computations. ITRF/WGS-84 coordination is therefore not a concern. The
Russian Federation has stated on a number of occasions that they plan
to provide GLONASS coordinate transformation data or change from their
PZ-90 reference to the ITRF.
The clock synchronization and related data among the three systems can
be established in a straightforward manner. The inter-system biases,
drifts and drift rates [e.g., between UTC(USNO) and UTC(USSR)] can be
easily distributed. All systems use or plan to use stable atomic
standards so the values are normally stable for periods of hours. Plans
have been structured to provide this data to users so that corrections
can be made to user clocks in much the same way that data message
corrections are currently applied by the user to the various GPS
spacecraft clocks.
Global cooperation and standardization are normally considered by
international organizations in addition to the individual states'
national standardization and measurement laboratories. These
organizations include ICAO for aviation, the IMO (International
Maritime Organization), the International Telecommunications Union
(ITU), the Bureau Internationale des Poids et Mesures (BIPM) and in the
US, the RTCA (formerly the Radio Technical Commission for Aeronautics),
the AGU (American Geophysical Union), the Naval Observatory (USNO) Time
Service, the National Institute of Standards and Technology (NIST) and
others.
Question: And finally "What is in it for us surveyors?" or better
phrased: "Our readers are eagerly looking forward to apply the
improvements to GNSS that are underway and promised. What are the
specific benefits for hydrographic surveying and offshore positioning
in your vision will realistically be provided by each individual system
in its own and/or by combining or integrating the systems? Can you also
give a timescale to the new opportunities?"
Ashkenazi: To tackle this question, it is important to give a brief
summary of the history of satellite navigation, and the reasons which
led the European Union to embark on the GALILEO Project. In the 1990's,
two independent satellite navigation systems were declared fully
operational. They were GPS and GLONASS, both designed to meet the
respective military requirements of the USA and the USSR (now Russia).
In the case of GPS, the system was later declared to be a dual-use
asset for both civil and military users, although all its funding still
comes through the US Department of Defense.
GPS was designed to provide pre-determined levels of horizontal and
vertical positioning accuracies 50% and 90% of the time, which were
considered to be adequate for the requirements of military navigation
on land, sea and air. Early civilian users of GPS in the 1980's
included yachtsmen, fliers of light aircraft and hikers. The advent of
Differential GPS or DGPS soon increased the number of civilian users of
GPS. With DGPS they could achieve quasi-instantaneous positioning
accuracies of the order of 1 to 3 metres, so long as they were located
within several hundred kilometres of a DGPS reference station and
received its broadcast of differential corrections. However, the real
breakthrough for civilian users of GPS came with the development of the
Carrier Phase Positioning technique, which was first proposed by two
radio astronomers from MIT. This was the beginning of centimetric GPS,
which led to hundreds of applications, ranging from Geodesy,
Geophysics, Oceanography, land and offshore surveying, to timing,
meteorology, agriculture, fisheries and space. GPS became an essential
measurement tool for monitoring both the natural and the built
environment.
This very wide variety of applications did not include safety-critical
transportation. There were, of course, some general transport
applications, such as fleet monitoring of trucks, taxis and cargo
boats, but not aircraft landing or railway signalling. GPS, which was
designed for military use, could not deliver on its own the tight
requirements of accuracy, integrity and continuity of service, which
are essential for safety critical applications. The missing ingredients
were not within GPS itself, but external to it.
The breakthrough in meeting this demand for extra accuracy, integrity
and continuity came with the development of the Wide Area Augmentation
Systems, WAAS in the USA, EGNOS in Europe and MSAS in Japan. Wide area
systems consist of one or more geostationary satellites, which provide
a platform for the broadcast of differential corrections and continuous
integrity messages coming from a dense network of ground based
satellite tracking stations.
However, there still remains the possibility of critical failure of
GPS. Some of this risk can be alleviated either by coupling GPS with
other well tested back up systems, such as INS and VOR/DME for air
navigation, and Loran-C for marine navigation, or by installing dense
LAAS's, which include pseudolites emitting GPS like signals. However,
the concern of "what happens in case of unintentional or intentional
failure of GPS" still remains. How can one certify a navigation system
for safety-critical civilian navigation, which is basically under the
control of a single country and the requirements of its military
establishment, however well intentioned these might be?
Hence, the European GALILEO System, which is being designed to be fully
compatible and interoperable with GPS, but will be operated under the
civilian control of the European Union. What difference will GALILEO
make to hydrographic surveying and offshore positioning operations
which, barring some exceptions such as ship docking, cannot be
considered as strictly safety-critical transportation operations, like
aircraft landing or railway signalling?
GALILEO will offer 4 types of service:
1.Open Access Service (OAS) which, like the GPS Standard Positioning
Service, will be freely available for mass market applications.
2.Commercial Access Service (CAS), which will involve encrypted value
added data in the signal, providing local augmentation services,
integration with communication networks, etc. 3.Safety of Life
Services (SAS), which will provide additional integrity, for
safety-critical applications in civil aviation, marine navigation and
train signalling. 4.Public Regulated Service (PRS), which will carry
encrypted signals under EU government control, providing greater
continuity of service for public service applications, such as police,
fire, customs etc. To fulfil this requirements, the signal will be
designed to offer better resistance to interference and jamming.
From the offshore positioning community's point of view, GALILEO will
offer some distinct advantages. To begin with, it will double the
number of available satellites, which will automatically increase
accuracy and integrity, and provide better coverage and therefore
better protection against masking in difficult offshore environments.
To achieve this, the GALILEO signal will have to be both fully
compatible with GPS (ie non-interfering operations for the benefit of
end users), and offer an acceptable level of inter-operability also
with GPS (eg a fully compatible geodetic coordinate datum and timing
system).
Another issue of importance to the offshore community is the type and
nature of the value-added data in the GALILEO CAS signal. Will CAS be
offered by the GALILEO Operator or be sub-contracted to private
companies, which would provide the interface with the different user
communities? GALILEO also proposes to offer a certain level of service
guarantees, an attribute which would distinguish it from GPS which
offers a completely free service, with no guarantees.
The commissioning of GALILEO in 2008 or soon afterwards will open a new
chapter in satellite positioning and navigation, with new opportunities
for commercial exploitation and increased competition, and a favourable
environment for generating new ways of using these multiple sources of
satellite data for better solutions and an even wider range of
applications.
Shebshaevich: To my mind, two development trends will give the main new
opportunities for GNSS applications, for hydrographic applications in
particular:
1.Progress in GNSS functional quality; 2.Progress in GNSS application
techniques.
The first one will make the GNSS function more accurate, available and
reliable for mass application. The second one will result in the GNSS
function penetration to all human activities where accurate positioning
and timing are attributes of event description.
The GLONASS functional improvements are based on its space segment,
ground segment (including augmentation systems) and user segment
modernisation and development. Starting with the year 2003, modernised
GLONASS spacecraft (S/C) will be launched with an increased 7-year
active life cycle, providing two civil signals available.
The GLONASS Development Program implies reconstructing the orbiting of
an 18 S/C constellation in 3-4 years. After that, the space segment
will be restored by the next generation of GLONASS S/C that are now
under design. These have a 10-12 year life cycle, reduced mass so that
six S/C can be launched into orbit at one time and three civil signals
that will be available to the users. (see Figure 5).
The orbital constellation improvements along with ground control
segment improvements shall provide the availability of several meters
accuracy level on the global and continuous basis.
During the next 10 years the coastal regions will be successively
covered by about 30 GLONASS/GPS differential reference stations based
on medium frequency marine beacons. About 25 differential stations will
operate on the main rivers and lakes at the same time. The main ports
shall be equipped by autonomous identification system (AIS) ground
stations. The long range navigation system CHAYKA will be modernised to
provide for a differential correction transmission capability. These
measures will result in about one meter accuracy together with
integrity monitoring and user notification of safety of navigation
concerns and provide reliable offshore positioning.
The user equipment segment is being modernised and has rapid growth.
The ship`s models of GLONASS/GPS user equipment designed and mass
produced by the Russian Institute of Radionavigation and Time are
presented in Figure 6. These include GLONASS/GPS OEM-products of
business card size for integrating in cartographic systems and AIS as
well as completed devices for autonomous usage and for coupling with
cartographic systems.
All equipments are 16-channel universal GLONASS/GPS receivers with code
and phase measurement capability for receiving and processing WAAS,
EGNOS and MSAS signals and data. Completed devices integrate marine
beacon signals and differential data receiving functions. The next
generation models will also integrate LORAN-C/CHAYKA extension. GALILEO
integration is planned beginning in 2007.
The next generation of GLONASS/GPS user equipment, available in two
years, incorporates the "system on a chip" (SOC) design approach. As a
result, power consumption and costs will go down significantly and
become reasonable for new mass applications that were not feasible
before. For example, monitoring of the geographic environment
including: ocean and sea, ice cover and iceberg dynamics,
ocean-atmosphere interaction processes, tsunami and earthquake
forerunners, etc.
Global positioning and telecommunications capabilities will be combined
in thousands of cheap compact autonomous monitoring platforms: fixed,
maneuverable or drifting. These can be the basis for global and
continuous process monitoring in a few years.
McDonald: Although the timescale for the new opportunities has been
configured, it is sensitive to the vagaries of annual funding and
changing priorities. The schedule for GPS is reasonably clear at any
given time but it frequently changes over time. Recent delays have
surfaced because of US (and other states) plans to combat international
terrorism as well as large expenditures for the second Gulf War. These
circumstances give priority to operations (receivers, installations,
personnel) as opposed to system improvements, e.g. system modernization
and GPS III (the next generation GPS spacecraft). The schedule for GPS
III slipped by 2-3 years this past January but some of this delay may
be revised. Other setbacks will likely follow.
This delay in GPS modernization (the main elements of which are shown
for the GPS Block IIF spacecraft in Figure 7) may be good news for
GALILEO in that the delay may significantly widen Galileo's window of
opportunity. This window is the time interval during which GALILEO will
have significantly better performance capabilities than GPS. It relates
primarily to the time span between the start of Galileo operational
capabilities and the establishment for GPS of modernized civil
operational capabilities.
The GPS new civil L2 signals may be available by about 2012 but the L5
civil signals (I5 and Q5 at 10 Mbps) will likely be delayed until 2016
or later. This provides GALILEO with a window of about 5-7 years or
more, depending upon when GALILEO becomes operational (see Figure 8).
A summary of the GPS capabilities planned for users in the future is
given in Table 2. Many of these constitute navigation, positioning,
time determination and related enhancements of great benefit to users.
Similar improved capabilities will be available in the Galileo and
GLONASS systems. This confluence will markedly improve the accuracy,
speed, timeliness and coverage available for survey, equipment
positioning and other diverse activities of hydrographic professionals
and other users.
NOTES: 1. WRC. World Radio Conference (ITU International
Telecommunications Union)
BIOGRAPHIES Mr. V. Ashkenazi is Chief Executive of Nottingham
Scientific Limited, an emeritus Professor of the University of
Nottingham, and a Fellow of the Royal Academy of Engineering. Professor
Ashkenazi has supervised about 40 doctorate students, and has acted as
a Consultant to a large number of commercial and government
organisations in Europe, North America and elsewhere. In 1996,
Professor Ashkenazi was awarded the James Alfred Ewing Medal by the
Royal Society and the Institution of Civil Engineers, in recognition of
his Significant Contribution to the Exploitation of GPS in a Wide Range
of Scientific and Commercial Applications.
Mr. B.V. Shebshaevich graduated from Leningrad Electrical Engineering
Institute in 1975. From 1975 up until the present time he has been a
member of the Russian Institute of Radio navigation and Time (RIRT)
team as engineer, head of the department, deputy director and now as
first deputy director. In 1984 he attained his PhD degree in
radiolocation and radio navigation.
Since l985 he has been involved in the GLONASS programme. He is and has
been project manager on more than twenty R&D projects in GNSS
positioning, timing and system integration.
Mr. K.D. McDonald is the Technical Director and Chairman of Navtech
Seminars, Inc. and president of Navtech Consulting in Alexandria, Va.
McDonald was scientific director of the U.S. Department of Defense
Navigation Satellite Program and executive director of the Four Service
Group that initiated the Navstar GPS program in the early 1970s. He
served as the director of Federal Aviation Administration satellite
development activities from 1974 to 1990. McDonald was a member of the
National Academy of Sciences /National Research Council Committee on
the Future of GPS during 1994-1995. He served as president of the U.S.
Institute of Navigation in 1990-1991 and president of the International
Association of Institutes of Navigation from 1997-2000.
ABBREVIATIONS USED
GNSS Global Navigation Satellite System
ITRS International Terrestrial Reference System
LAAS Local Area Augmentation System
LBS Location Based Services
PPP Public Private Partnership
RIRT Russian Institute of Radionavigation and Time
RTK Real Time Kinematic
WAAS Wide Area Augmentation System
WRC World Radio Conference
ITU International Telecommunications Union
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