September 25, 1998
Office of the Assistant Secretary of Defense
Department of Defense
Mortimer L. Downey, IGEB Co-Chair
Deputy Secretary of Transportation
Department of Transportation
Chair, GPS Interagency Advisory Council
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GIAC
GPS Interagency Advisory Council
September 25, 1998 |
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| MEMORANDUM FOR: | Arthur L. Money, IGEB Co-Chair
Office of the Assistant Secretary of Defense Department of Defense Mortimer L. Downey, IGEB Co-Chair
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| FROM: | Charles W. Challstrom
Chair, GPS Interagency Advisory Council |
| SUBJECT: | GPS Modernization |
At the September 15, 1998, meeting of the GPS Interagency Advisory Council (GIAC), discussions centered on issues associated with GPS Modernization. As you probably know, the GIAC was formed in 1995 by an exchange of letters between the Secretary of Interior and the Secretary of Transportation to represent the non-transportation users of GPS. I believe this memorandum accurately describes the consensus view of the GIAC membership and is provided for your consideration.
1. Set Selective Availability (SA) to a zero state immediately.
We do not believe SA provides additional national security
sufficient to warrant its continuation. To the contrary, the
continuation of SA only serves to delay acceptance of GPS as the
international foundation for positioning and timing systems, and
may, therefore, pose a greater risk to national security.
2. Implement a civil C/A code, similar to that of L1, on L2 as
soon as possible.
We recommend modification of the last twelve IIR satellites and
the first six IIF satellites to provide a C/A-centered signal on
L2 at the earliest opportunity. The basis of this recommendation
is our concern that sufficient dual-frequency GPS signals will
not be available to the civil sector by the solar maximum
expected in 2011-2012. Furthermore, early fielding of a civil
signal at L2 will significantly increase the utility of GPS and
increase its acceptance as an international standard.
3. Identify a third civil signal suitable for use by aviation
that, when used in conjunction with civil signals on L1 and L2,
supports long-distance precise differential positioning.
We accept and support the Federal Aviation Administration's
requirement for a second GPS signal in a band with an
Aeronautical Radio Navigation Service (ARNS) allocation.
However, the frequency selection of this third signal must also
support the establishment of a nationwide precise
(centimeter-level) positioning capability. If this third signal
is not implemented, we are certain a competitive system, either
private or foreign, will replace GPS as the international system
of choice.
4. Define a national funding strategy to assure GPS will
continue.
We are greatly concerned by recent activities associated with
funding for GPS and its government-provided augmentations. They
indicate a lack of understanding for our nation's dependency on
the services provided by GPS in our day-to-day activities. Due
to the importance of GPS, its funding process must not be reliant
on multi-departmental funding mechanisms. A joint committee
mechanism, similar to that used for government printing, should
be implemented to provide a completely unified funding process
and best support IGEB policy decisions.
5. Increase the effort to retain GPS spectrum.
There is a serious threat to the utility of GPS from
communications systems that are competing for GPS spectrum. GPS
spectrum issues must have the highest level of support from all
agencies involved in radio spectrum allocation and agencies that
use GPS to accomplish their missions.
We are aware that there are significant funding issues associated with some of these goals, and many IGEB agencies have not had sufficient time to develop budget initiatives to support the near-term funding requirements. Concerned that policy decisions may be unduly affected by agency budget competition, we felt it necessary to explicitly state what is in the best interests of the Nation, our agencies, and our constituents. The GIAC membership will continue to support activities to achieve these goals to the fullest extent possible. Your due consideration of these goals is requested.
cc:
Stephen G. Moran, Office of Science and Technology Policy
Robert Bell, National Security Council
Lieutenant General Douglas D. Buchholz, Department of Defense
D. James Baker, Department of Commerce
Gary Bachula, Department of Commerce
Melinda L. Kimble, Department of State
Mark Schaefer, Department of Interior
Glenda Humiston, Department of Agriculture
Robert Spearing, National Aeronautics and Space Administration
Mark A. Boster, Department of Justice
General John Gordon, Central Intelligence Agency
GPS INTERAGENCY ADVISORY COUNCIL
FEDERAL GEODETIC CONTROL COMMITTEE
1315 EAST-WEST HIGHWAY ROOM 8657
SILVER SPRING, MARYLAND 20910-3282