Global Positioning Technology: Opportunities for Greater Federal Agency
Joint Development and Use (Letter Report, 09/28/94, GAO/RCED-94-280).

Recent technology has made it possible to greatly improve the accuracy
of global positioning information available from satellites. This
technology, called Differential Global Positioning Systems, allows
pilots, surveyors, and other using satellite positioning information for
civil uses to determine their position on earth to within a few
meters--or even a few centimeters. Many civilian federal agencies, such
as the Federal Aviation Administration, are actively pursuing the use of
this technology. GAO looked into whether federal agencies are taking
full advantage of opportunities to share or jointly develop their
systems so as to minimize the cost to taxpayers. This report discusses
(1) the extent to which agencies have been developing joint systems or
sharing equipment and (2) additional steps that may be needed to enhance
joint development or sharing of Differential Global Positioning Systems
equipment, facilities, and information.

--------------------------- Indexing Terms -----------------------------

 REPORTNUM:  RCED-94-280
     TITLE:  Global Positioning Technology: Opportunities for Greater 
             Federal Agency Joint Development and Use
      DATE:  09/28/94
   SUBJECT:  Interagency relations
             Research and development
             Satellites
             Transportation operations
             Geographic information systems
             Technology transfer
             Federal procurement
             Information gathering operations
             Systems compatibility
             Systems design
IDENTIFIER:  DOT Intelligent Vehicles and Highway System
             FAA Wide Area Augmentation System
             IVHS
             
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Cover
================================================================ COVER


Report to Congressional Requesters

September 1994

GLOBAL POSITIONING TECHNOLOGY -
OPPORTUNITIES FOR GREATER FEDERAL
AGENCY JOINT DEVELOPMENT AND USE

GAO/RCED-94-280

Global Positioning Technology


Abbreviations
=============================================================== ABBREV

  BLM - Bureau of Land Management
  DGPS - Differential Global Positioning System
  DOD - Department of Defense
  DOT - Department of Transportation
  EPA - Environmental Protection Agency
  FAA - Federal Aviation Administration
  NGS - National Geodetic Survey
  NOAA - National Oceanic and Atmospheric Administration
  OMB - Office of Management and Budget
  RINEX - Receiver Independent Exchange

Letter
=============================================================== LETTER


B-258005

September 28, 1994

The Honorable Norman Y.  Mineta
Chairman
The Honorable Bud Shuster
Ranking Minority Member
Committee on Public Works and Transportation
House of Representatives

Recent technology has made it possible to greatly improve the
accuracy of global positioning information available from satellites. 
This technology, called Differential Global Positioning Systems, or
DGPS, allows pilots, surveyors, and others using satellite
positioning information for civil uses\1 to determine their position
on earth to within a few meters--or even a few centimeters.  Many
civilian federal agencies are actively pursuing the use of this
technology.  For example, to improve aircraft navigation and
landings, the Federal Aviation Administration (FAA) is planning a
national DGPS network costing about $500 million. 

In response to your request of July 21, 1993, we performed a review
to determine whether federal agencies are taking full advantage of
opportunities to share or jointly develop their systems so as to
minimize the cost to taxpayers.  Specifically, we focused on (1) the
extent to which agencies have been developing joint systems or
sharing equipment and (2) additional steps that may be needed to
enhance joint development or sharing of DGPS equipment, facilities,
and information. 


--------------------
\1 Our review focused on civil use of global positioning system
technology.  The Department of Defense operates the global
positioning system and does not use DGPS technology for military
operations. 


   RESULTS IN BRIEF
------------------------------------------------------------ Letter :1

Between 1988, when federal agencies began to use differential global
positioning system technology, and 1993, few federal agencies were
developing joint systems or sharing equipment.  To a large extent,
this early lack of coordination is not surprising.  Agencies differed
in the applications they were trying to develop, and the federal
government had no clear mechanism to coordinate interagency efforts. 
Beginning in 1993, agencies changed this approach in two ways. 
First, two agencies developing large-scale systems--the Coast Guard
and Federal Aviation Administration--changed their systems to make
them easier for other agencies to use.  Second, the Departments of
Defense and Transportation formed a task force to study global
positioning issues, including options for greater joint development
or use of differential global positioning system technology by
civilian agencies--at least on a voluntary basis.  However, the
interagency coordinating mechanisms proposed by the task force and
now being put in place have no authority over civilian agencies
outside the Department of Transportation.  This limited authority
leaves other civilian agencies free to develop systems on their own. 

The rapid growth in government-sponsored differential global
positioning system applications is expected to continue.  Such growth
and the potentially significant budget implications it carries
heighten the need for effective governmentwide coordination. 
Continuing efforts are under way to address the technical aspects of
such coordination--for example, development of standards to ensure
that various differential global positioning system applications can
use the same equipment.  However, these efforts address technical
issues only--not issues related to ensuring that agencies will agree
to coordinate their development and use of differential global
positioning systems. 


   BACKGROUND
------------------------------------------------------------ Letter :2

Global positioning information comes from a network of 24 Department
of Defense (DOD) satellites.  Planes, boats, vehicles, and mapping
and survey teams can determine their position on earth by using
equipment that receives and interprets signals from these satellites. 
For civil applications, the satellites provide a signal that is
accurate to about 100 meters without the use of DGPS. 

DGPS is a technology for improving the accuracy of this positioning
information.  This greater accuracy is potentially useful in such
ways as improving the accuracy of maps, enhancing search and rescue
efforts, improving navigation in crowded waterways, and helping
planes land in bad weather.  DGPS increases the accuracy of the
satellite signal through the use of earth-located "base" or
"reference" stations (see fig.  1).  The cost of these base stations
varies from about $10,000 to $200,000 depending on the type of
application and communication link needed to get the information to
the user.  Other costs are for acquiring field receivers that can
capture the signals from satellites and base stations and for
monitoring and maintaining the equipment and the data it generates. 

   Figure 1:  Basic Components of
   DGPS

   (See figure in printed
   edition.)

   Note:  Positioning data is
   needed from at least four
   satellites to determine the
   three-dimensional position on
   earth.

   (See figure in printed
   edition.)

DGPS takes two main forms, each with its own equipment requirements. 
One form, called real-time, transmits positioning information
instantaneously to the user, while the second form, called
post-processing, stores the information for later use.  Real-time has
been used largely for navigation, and post-processing has been used
mainly for mapping and surveying.  Costs are higher for equipment and
operations related to real-time than for post-processing. 

DGPS development is still considered to be in its infancy.  One of
the first federal applications was a system installed by the U.S. 
Forest Service in 1988 for managing forest resources.  While usage in
both the government and the private sector has mushroomed since that
time, global positioning system industry officials estimate that
about 95 percent of the market remains to be tapped.  They expect
DGPS to be commonplace for such additional activities as responding
to medical and police emergencies, locating and tracking vehicles,
and installing utility services.  This continued growth means that
the federal investment in DGPS technology--already more than $518
million through fiscal year 1998--can be expected for some time to
come. 


   SEVERAL FACTORS CONTRIBUTED TO
   LIMITED COORDINATION DURING
   EARLY DEVELOPMENT OF DGPS
------------------------------------------------------------ Letter :3

Most DGPS applications within the federal government before 1993
focused on single-agency systems.  We reviewed the activities of nine
federal agencies that had been active in designing or implementing
DGPS applications during this period.\2 (Table 1 shows the nine
agencies and the kinds of applications they were developing.  For
additional details on each agency's plans, see app.  I.) Eight of the
nine began their efforts by designing or implementing a single-agency
approach.  In other words, each agency planned to acquire its own
equipment, including base stations, and to set up the system to meet
specific agency needs. 



                           Table 1
           
                   Agency DGPS Applications



                                        Surveying
                                        and
Agency            Aviation   Marine     mapping    Other
----------------  ---------  ---------  ---------  ---------
Federal Aviation  X
Administration

Coast Guard                  X                     X\a

Environmental                           X
Protection
Agency

Bureau of Land                          X
Management

Forest Service                          X

U.S. Geological                         X
Survey

St. Lawrence                                       X\a
Seaway
Development
Corporation

National Oceanic                        X
and Atmospheric
Administration

Army Corps of                X                     X\a
Engineers
------------------------------------------------------------
\a Includes buoy setting and/or dredging. 

The one exception to this single-agency approach was the National
Oceanic and Atmospheric Administration's (NOAA).  NOAA lacked the
funds to build its own system but was able to use the Coast Guard's
equipment to supply its information requirements.  (We will discuss
the NOAA-Coast Guard effort in more detail later in this report.)

In many respects, it is not surprising that joint development of DGPS
applications was initially limited.  One main reason was that the
type of application and geographic coverage varied considerably.  For
example, the Coast Guard and FAA had navigation applications, but the
Coast Guard's was for marine navigation largely along the coast and
in the Great Lakes, while FAA's was for aircraft navigation
throughout the country.  Many other agencies had nonnavigational
applications, such as surveying and mapping, which required a
different kind of system (post-processing rather than real-time) and
which often focused on those areas of the country they were
responsible for managing. 

Even when agencies had similar DGPS needs and applications, other
factors often limited the amount of joint development that could
occur.  These factors related both to the operation of the system and
to a limited opportunity or need to coordinate with other agencies. 


--------------------
\2 We contacted 13 federal agencies that were involved in
transportation, surveying, or mapping--the activities supported by
DGPS.  Nine of them indicated they had been actively designing,
implementing, or operating DGPS applications. 


      INCOMPATIBLE EQUIPMENT AND
      INCONSISTENT OPERATING
      PROCEDURES
---------------------------------------------------------- Letter :3.1

Single-agency applications developed for mapping, surveying, and
related uses sometimes could not share information with other
applications because equipment was incompatible.  Equipment developed
by one manufacturer can have software programs or data-storing
formats that cannot be used by another manufacturer's equipment.  For
example, a Bureau of Land Management (BLM) official said several
other agencies stopped trying to access information from a BLM base
station because of the time needed to resolve equipment
incompatibility problems.  Similarly, several agencies were
unsuccessful in accessing Forest Service data relating to the
locations of streams, bridges, and other features because of computer
hardware and DGPS data format limitations.  Although a common data
format (called Receiver Independent Exchange, or RINEX) had been
developed that would allow field receivers made by one manufacturer
to share data with post-processing base stations from another
manufacturer, several studies conducted during 1991-94 indicated that
some manufacturers do not always adhere to this format. 

Another information-sharing problem stemmed from differences in
agency operating procedures.  For functions like mapping and
surveying, during which positioning data are collected and stored for
later use, agencies establish specific time intervals at which the
base station will collect signals from the global positioning
satellites.  However, these intervals may vary within and between
agencies, meaning that positioning data collected and stored to
support one application may not support another agency's application. 
Also, the hours when equipment was available and operating varied. 
For example, some BLM offices operated their base stations 12 hours a
day, 3 days a week, while others operated 12 to 24 hours a day, 5 or
7 days a week.  The St.  Lawrence Seaway Development Corporation
operated its equipment only for short periods of time when the agency
was positioning buoys.  Finally, the length of time an agency will
archive the positioning data ranged from about 2 weeks to
permanently.  Officials with three agencies said they were reluctant
to use DGPS data from other agencies unless they had assurance that
the data would be archived long enough to resolve questions that
might arise after a project was finished. 


      LIMITED INFORMATION ABOUT
      OTHER AGENCIES' EFFORTS
---------------------------------------------------------- Letter :3.2

Many agency officials said they were unaware of what other agencies
were doing and did not know where to go to find out.  For some
agencies, this situation may not have changed.  For example, during
our review we spoke with an Environmental Protection Agency (EPA)
official in Chicago who wanted to implement DGPS for his region.  The
official was unaware that the Coast Guard had a base station in
Milwaukee, about 90 miles away, and was planning to put in additional
base stations on the Mississippi River that could serve his region. 
After we informed him about the Coast Guard's equipment, he said he
planned to investigate its possible use. 

Some attempts at providing information had been made, but they were
split between several sources, and the information available was
largely incomplete: 

  In 1992, the Federal Geographic Data Committee, an interagency body
     responsible for coordinating all mapping and surveying activity,
     established a subcommittee that maintained a list of federal,
     state, and private-sector DGPS base stations, but the list was
     incomplete. 

  In 1989, the Coast Guard established a committee to provide a forum
     for public- and private-sector users to exchange technical
     information about the global positioning system, but the
     committee did not maintain data on the location and
     characteristics of federal DGPS facilities or capabilities. 
     Since 1990, the Coast Guard has also operated a center that
     provides information on the status and operational condition of
     the global positioning system satellites and other related
     navigation systems, but this center does not provide information
     about federal DGPS facilities. 


      FEW INCENTIVES FOR JOINT
      DEVELOPMENT
---------------------------------------------------------- Letter :3.3

Agencies with systems already under way had little incentive to share
information about their systems with other agencies.  Several agency
officials said coordinating DGPS activities with other agencies
requires additional work and expense and can delay the development
and implementation of an individual agency's DGPS applications. 
Agencies also indicated that, besides the initial development's being
affected, the ongoing operation of the system could also be adversely
affected because of the additional drain on resources.  For example,
a Forest Service official said his office lacked the staff to provide
technical assistance and support to agencies unfamiliar with DGPS
applications.  As a result, his office stopped sharing DGPS data
unless the other agency agreed to share data in return.  A BLM
headquarters official said that because equipment is often not
designed for multiagency use, agency personnel in the field are
reluctant to spend the additional time and resources needed to make
DGPS equipment or data available to other agencies. 

Lacking any governmentwide requirements or policies on how they
should develop their DGPS applications, agencies established their
own polices and procedures for operating the equipment and sharing
the data with other agencies.  The differences in procedures
sometimes extended to individual offices within an agency.  For
example, a Forest Service office in one region of the country has an
interagency agreement with a nearby BLM office to share DGPS data,
while Forest Service offices in other regions restricted access to
DGPS data in order to safeguard the integrity of other sensitive
information stored on the same computer system.  Several EPA regions
established an ad hoc committee to coordinate the development and
implementation of DGPS because they had not received any guidance
from their headquarters office. 


   AMID GROWING CONCERN, STEPS
   WERE TAKEN TO IMPROVE
   COORDINATION AND JOINT USE
------------------------------------------------------------ Letter :4

Several agency officials and DGPS experts we contacted\3

noted that the development of additional DGPSs or purchase of
additional DGPS equipment by federal agencies was increasing the
potential for overlap and duplication and that some had already
occurred.  For example, the Forest Service and BLM installed 11 base
stations in Arizona and New Mexico--6 for the Forest Service, 5 for
BLM, and according to agency officials, both agencies basically use
the same positioning data for mapping and natural resource inventory
applications and have the same type of DGPS equipment.  DGPS experts
said that to meet positioning requirements for resource management
applications, only one or two DGPS base stations are needed within
most states.  Forest Service and BLM officials agreed that some of
their base stations overlap and duplicate one another, yet BLM is
planning to install four more in these two states because of
difficulties in obtaining ready access to the Forest Service's DGPS
equipment. 

In 1993, anticipating the expected future growth in DGPS, some
federal agencies took steps to facilitate greater joint development
of DGPS capabilities.  These steps fell into two categories: 
modifying DGPSs to accommodate the needs of other agencies, and
examining issues related to greater interagency coordination of DGPS
applications. 


--------------------
\3 We discussed DGPS developments with industry and federal agency
officials with technical knowledge of DGPS and/or responsibilities
for designing and implementing DGPS programs.  See app.  II for a
list of the officials contacted. 


      MODIFYING DGPSS FOR
      MULTI-AGENCY USE
---------------------------------------------------------- Letter :4.1

We identified three instances in which agencies had modified or were
modifying their DGPS equipment or systems to accommodate joint use. 

  To accommodate NOAA's mapping and surveying requirements, the Coast
     Guard acquired dual-frequency base stations instead of
     single-frequency ones.  NOAA contacted the Coast Guard because
     it did not have the resources to set up its own system. 
     However, NOAA's surveying and mapping needs required
     dual-frequency equipment in order to provide greater accuracy
     than the Coast Guard's planned single-frequency equipment would
     provide.  Such equipment was more expensive than what the Coast
     Guard initially planned to buy and had funds to pay for.  When
     the equipment dropped in price, however, the Coast Guard was
     able to obtain the more sophisticated equipment within the
     amount originally budgeted for the system.  In return for the
     Coast Guard upgrading its DGPS base station equipment, NOAA has
     agreed to perform the geodetic surveying needed to install the
     base station equipment. 

  The Office of Management and Budget (OMB) asked the Army Corps of
     Engineers, in lieu of developing a separate DGPS in the lower
     Mississippi River Valley, to determine whether the Coast Guard's
     system would meet its needs for surveying and mapping
     information for dredging, levee construction, and other related
     activities on the river.  Corps officials said they were
     reluctant at first to pursue a joint venture because of concerns
     that the Coast Guard's system, which was designed to meet
     navigational needs, would not provide data sufficiently accurate
     for dredging and hydrographic surveying purposes.  However,
     after testing an enhanced version of the Coast Guard's system,
     Corps officials found it could meet their needs.  In 1994, the
     Corps adapted its plans so that it could use the Coast Guard's
     system and expand it to cover inland waterways rather than build
     a separate system. 

  To accommodate a request by NOAA's National Geodetic Survey (NGS)
     for additional DGPS base stations for precise mapping and
     surveying, FAA modified its Wide Area Augmentation System for
     aviation navigation.  Each FAA base station will be equipped
     with computer and telecommunications equipment to meet NGS'
     mapping and surveying needs as well as to provide the navigation
     information for which the system was initially designed.  FAA's
     modifications will also allow other agencies to use its system. 

Substantial dollar savings will result from these examples of joint
use.  A NOAA official anticipates that NOAA's use of the Coast Guard
and FAA systems will save about $10 million in equipment costs alone,
and perhaps millions in operating costs over the life of the project. 
The Corps of Engineers expects to save $25 million to $40 million
over 5 years by avoiding the need to spend money for equipment,
installation, operation, and maintenance of conventional microwave or
other systems for dredging and surveying.  Savings of this magnitude
are even more significant considering that the initial expense for
the Coast Guard's system being used by the Corps was $17.8 million. 
Corps and Coast Guard officials also believe using a common system
will enhance operational efficiencies and marine safety. 


      TASK FORCE ON JOINT
      DEVELOPMENT AND USE OF DGPS
---------------------------------------------------------- Letter :4.2

In early 1993, with both military and civil use of the global
positioning system growing, concerns were expressed about how best to
balance these competing needs while encouraging maximum civil use of
the system.  In May 1993, DOD and the Department of Transportation
(DOT) formed a task force to review these DGPS issues.\4 In a
December 1993 report, the task force concluded that continuing the
current ad hoc approach to DGPS development would likely result in
unnecessary duplication.  To resolve some of the barriers that impede
joint development and use, the task force made several
recommendations, including the following: 

  Reorganizing the civil federal global positioning system management
     structure established in the 1987 memorandum of agreement by (1)
     elevating DGPS decision-making within DOT to the assistant
     secretary level; (2) expanding the former DOT Navigation Council
     into a new Positioning/Navigation Executive Committee made up of
     representatives of DOT agencies; and (3) creating an interagency
     advisory council that would represent to the Executive Committee
     those agencies primarily interested in DGPS for nonnavigational
     purposes, such as surveying and mapping.  DOT has since begun to
     implement this structure. 

  Conducting an additional study to determine the feasibility of
     developing a nationally integrated augmented system providing
     DGPS services for aviation, marine, and land users.  This
     augmentation study, scheduled for completion in 1994, will
     examine existing and planned federal agencies' DGPS applications
     and determine the technical feasibility of developing common
     equipment standards and communication formats suitable for use
     by multiple DGPS users.  However, (as discussed below) the
     augmentation study will not address the organizational structure
     necessary to implement this system and ensure governmentwide
     coordination concerning DGPS. 


--------------------
\4 In 1987, through a memorandum of agreement with DOD, DOT agreed to
serve as the primary interface within the U.S.  government for all
civil global positioning system matters.  Within DOT, requirements
for transportation were coordinated through the DOT Navigation
Council.  Input from non-DOT agencies and other civil users of the
global positioning system was provided to the Navigation Council
through a separate committee sponsored jointly by the Coast Guard and
DOT's Research and Special Programs Administration. 


   IMPROVED COORDINATION
   IMPORTANT, BUT STEPS TO DATE
   ARE NEITHER COMPLETE NOR
   SUFFICIENT
------------------------------------------------------------ Letter :5

The growth in government-sponsored DGPS applications is expected to
continue.  The budgetary implications involved in designing new
systems, acquiring equipment, and administering DGPS applications
over time will increase the need to improve coordination in the years
to come.  However, it is doubtful that the management structure being
set in place as a result of the DOD-DOT task force's recommendations
will be adequate to achieve full governmentwide coordination of all
DGPS users. 


      SUBSTANTIAL GROWTH EXPECTED
      IN FEDERALLY SPONSORED DGPS
      ACTIVITIES
---------------------------------------------------------- Letter :5.1

The need for improved coordination can be seen in the anticipated
growth of DGPS.  In the near term, the federal investment for DGPS is
sizeable.  For example, FAA's Wide Area Augmentation System alone is
expected to cost about $500 million during 1995-2000, and the Coast
Guard plans to spend about $18 million for its DGPS network, most of
this in 1994-95.  These expenditures center on (1) an FAA network of
up to 33 base stations throughout the entire United States\5 and (2)
a Coast Guard system of 63 base stations along the coastal United
States and Mississippi River basin.  According to several experts we
contacted, once these systems are in place, the substantial
infrastructure of base stations could potentially meet the needs of
many federal and other DGPS users.  (See app.  I for a description of
the capabilities of these systems.)

The growth in federally owned or federally sponsored DGPS
applications is not expected to stop once the systems currently being
planned or implemented are in place.  Many of the nine agencies we
reviewed are planning other applications for the future, and other
agencies are likely to follow.  At least 15 other federal agencies
have identified future DGPS applications, according to an official
conducting the DGPS augmentation study.  Officials at most federal
agencies we contacted said that, because some key applications were
still undergoing research and development or operational testing,
they had not quantified planned expenditures for some future
applications. 

The following examples from the nation's highway and rail
transportation systems as well as natural resource agencies'
applications illustrate some of the potential DGPS expansion in which
the federal government will likely be involved: 

  For highways, DGPS will play an increasing role in some key
     applications of the Intelligent Vehicle Highway System.\6
     Several demonstration projects are under way to test the
     feasibility of using DGPS for automatic vehicle location, in-car
     navigation, and commercial vehicle routing and scheduling.  For
     example, such private sector companies such as Southeastern
     Freight Lines and the J.B.  Hunt trucking company expect to use
     DGPS to improve vehicle tracking, scheduling, and maintenance,
     according to an American Trucking Association official.  The
     global positioning system industry projects the market for such
     applications to be about $2 billion to $5 billion by the year
     2000. 

  For rail systems, the Federal Railroad Administration expects that
     rail companies will be able to use DGPS to monitor the speed and
     location of trains and thereby increase the safety and
     efficiency of rail traffic routing.  Burlington Northern and
     Union Pacific railroads plan to test DGPS as part of a Positive
     Train Separation system to monitor the speed and location of
     trains. 

  The National Park Service, the U.S.  Fish and Wildlife Service, and
     other federal natural resource agencies plan greater use of DGPS
     for mapping and various natural resource inventory activities. 
     Use of DGPS is more reliable and much less expensive than
     traditional surveying methods, which typically require that
     survey crews spend days or weeks, often in remote areas, in
     order to inventory wetlands, timber stands, or other resources. 
     The prospect of real-time DGPS-assisted aerial photography will
     also provide efficiencies by lessening the need for ground-based
     personnel used to set out visual markers as reference points,
     according to a Forest Service official. 

Growth is also expected in state and local government activities that
receive federal support, such as highway construction and mass
transit applications.  For example, with funding from the Federal-Aid
Highway Trust Fund, the Tennessee and Kentucky departments of
transportation have installed base stations and other equipment to
produce highway maps for transportation planning.  Transit
authorities in Milwaukee and Denver have spent $8.3 million and $11
million, respectively, on DGPS-based vehicle location systems to
increase the safety and efficiency of transit bus fleet management. 
According to a Federal Transit Administration official, other transit
agencies around the country are considering installing similar bus
tracking systems, which are 80 percent federally funded.  Neither the
Federal Highway Administration nor the Federal Transit Administration
requires that such federally funded DGPS applications be coordinated
with other federal DGPS applications. 


--------------------
\5 FAA also plans to have a network of base stations at up to 701
airports to provide greater accuracy needed for precision landings. 
The cost of this system, much of which will be borne by local
airports, is not part of the $500 million estimate for FAA's Wide
Area Augmentation System. 

\6 The Intelligent Vehicle Highway System involves the integration of
electronics, communications, computer and control systems into both
vehicles and highways and is designed to enhance transportation
mobility, energy efficiency, and environmental protection.  We
recently testified on the progress DOT has made on this system (Smart
Highways:  Challenges Facing DOT's Intelligent Vehicle Highway
Systems Program [GAO/T-RCED-94-253, June 29, 1994]). 


      ADDITIONAL ACTIONS WOULD
      STRENGTHEN INTERAGENCY
      COORDINATION
---------------------------------------------------------- Letter :5.2

While these developments underscore the desirability of greater
coordination, the mechanisms set in place as a result of the DOD-DOT
task force's recommendations are not sufficient to accomplish this
task.  If the augmentation study being conducted as a follow-up to
the task force's work finds that a common network of base stations
can be established for joint use, it is critical that an effective
mechanism be in place to coordinate subsequent development of DGPS
applications.  However, the current mechanism does not have authority
over many agencies that use DGPS. 

Full coordination of DGPS applications essentially requires
establishing a clear bridge between two categories of DGPS
users--those who use it for real-time navigation and those who use it
for post-processing applications such as surveying, mapping, and
related purposes.  Federal agencies in the first category are DOT
agencies such as FAA and the Coast Guard that, under the reorganized
management structure now being put in place, are coordinated through
DOT's Positioning/Navigation Executive Committee.  Federal agencies
in the second category are non-DOT agencies such as NOAA, the Forest
Service, and the U.S.  Geological Survey that are coordinated through
the Federal Geographic Data Committee, the separate group responsible
for interagency use of spatial data for surveying and mapping.  Thus
far in the development of DGPS applications, there has been progress
in establishing formal mechanisms for DGPS issues between these two
groups.  However, substantial efforts will be required to achieve
full governmentwide coordination. 

Each of these categories of user agencies has improved coordination
within its own group, but coordination between the two sets of
agencies has not significantly changed.  For example, after the
December 1993 report by the DOD-DOT task force, the Federal
Geographic Data Committee made its own proposal for a consolidated
DGPS network for mapping, surveying, and related uses.  Under the
proposal, any federal agency involved in surveying or mapping
applications of DGPS or any federally funded application related to
such applications would be required to use this network.  According
to a committee official, the committee withdrew the proposal when DOT
expressed concerns that creation of such a network would be premature
because the technical feasibility of creating a network that could be
used both for navigation and for surveying and mapping applications
was still being studied. 

In our view, the organizational structure that has been put in place
as a result of the task force's recommendations does not take both
user groups equally into account.  Under this structure, formulating
policy for all civil DGPS applications will rest with the DOT
Positioning/Navigation Executive Committee.  Linkage with the
surveying, mapping, and other applications of non-DOT agencies--such
as those coordinated through the Federal Geographic Data
Committee--is through a separate Interagency Advisory Council, which
is composed of representatives from non-DOT agencies and reports to
the Positioning/Navigation Executive Committee.  Thus, while non-DOT
agencies would have an opportunity to provide their views, decisions
would ultimately be made by a committee composed solely of DOT
representatives. 

It is understandable that the task force did not propose a
coordinating body that included non-DOT agencies because DOT has
never received executive or legislative branch authority to
coordinate non-DOT agencies' use of DGPS.  Although DOT has agreed
with DOD to serve as the point of contact for all civil applications
of the global positioning system, neither the administration nor the
Congress has expressly designated DOT as having authority over
potential DGPS applications of non-DOT agencies.  Thus, while the
Positioning/Navigation Executive Committee may be able to set policy
for DOT agencies on navigational uses of DGPS, its authority over
non-DOT agencies is open to question. 

The Positioning/Navigation Executive Committee has been attempting to
develop memorandums of agreement between DOT and non-DOT agencies as
a way of facilitating greater interagency development and use of
DGPS.  For example, the joint-use projects described above between
the Coast Guard and the Corps of Engineers and the National Geodetic
Survey were carried out under these memorandums.  According to DOT
officials, such memorandums have been helpful in structuring the
conditions and costs associated with interagency use of DGPS
equipment and information. 

Even if such agreements are established, however, such an
agency-by-agency approach does not ensure that federal agencies, or
others receiving federal funds for DGPS applications, would not buy
their own equipment instead of using the available equipment and
facilities.  For example, if the task force and DOT decisionmakers
conclude that a nationwide system of base stations could be used by
most or all federally owned and federally sponsored DGPS
applications, the Positioning/Navigation Executive Committee has no
authority to require non-DOT agencies to even study the possibility
of using the system for future applications. 

OMB appears to be the federal agency in the best position to resolve
this problem, since it is the executive branch agency responsible for
developing governmentwide coordinative mechanisms.  As such, OMB is
the logical choice to develop interagency policies to promote
interagency cooperation concerning joint DGPS development and use. 
In addition, OMB's budget review process offers another potential
opportunity to help ensure that all agencies examine the alternative
of using existing equipment and facilities before proceeding with an
agency-specific--and potentially duplicative--system.  This
coordination has already occurred to a limited extent.  At the nine
agencies we reviewed, one of the instances in which interagency
coordination has led to budgetary savings was prompted by questions
raised during budget review by OMB.  As discussed above, the Corps of
Engineers had initially intended to fund its own system, but OMB
recommended that the Corps investigate joint use of the Coast Guard's
system. 

Thus far, no specific requirement exists for agencies to take such
steps as a prerequisite to submitting budget proposals for new DGPS
applications or for funding DGPS applications by state or local
governments.  Our discussions with OMB personnel indicated that
although some budget examiners had raised issues about DGPS
applications in individual circumstances, the effort was not
uniformly enforced across the many federal agencies involved in
developing or funding DGPS applications.  Given that the existing
mechanisms for cooperation and coordination are voluntary in nature
for most federal agencies, a formal check of this kind may be an
appropriate way to ensure a cost-effective approach to DGPS.  It
would still allow agencies to develop agency-specific DGPS
applications, provided the unique requirements of such systems could
not be met by the existing federal DGPS infrastructure. 


   CONCLUSIONS
------------------------------------------------------------ Letter :6

In the past, agencies have not coordinated their efforts to develop
DGPS, and this has led to some duplication of facilities and
equipment.  Since early 1993, coordination has improved, resulting in
significant cost savings.  However, these instances of coordination
were ad hoc efforts.  Growing evidence indicates that an
agency-by-agency approach to planning and installing DGPS
applications may continue to result in duplication and unnecessary
expense.  The work of the DOD-DOT task force represents the strongest
effort to date to develop a more coordinated, systematic approach to
managing the growing demands for DGPS.  We believe, however, that the
approach that has resulted for coordinating DGPSs and DGPS
applications across agency lines is insufficient.  It does not ensure
that all federal agencies will first look to jointly use the
substantial existing and planned infrastructure of DGPS equipment and
facilities before designing systems solely to meet their individual
needs.  Ongoing DOD-DOT efforts to address technical and equipment
compatibility issues do not address the issues of interagency
coordination.  Without governmentwide coordination and
accountability, agencies can still elect to go their own way, perhaps
spending money on facilities and equipment already available
elsewhere. 


   RECOMMENDATIONS
------------------------------------------------------------ Letter :7

To help ensure the cost-effectiveness of future federal or federally
financed DGPS applications, we recommend that the Office of
Management and Budget take the lead in establishing a more
coordinated governmentwide approach to managing DGPS.  Such an
approach could take the form of establishing a coordinative mechanism
for all civil DGPS applications and giving it the authority to
establish policies, procedures, and standards needed to facilitate
joint development and use of DGPS technology.  It could also take the
form of requiring that any federal agencies proposals to (1) add DGPS
base stations in fiscal years 1998 and beyond or (2) participate in
federal financing of base stations to be acquired by state or local
government units demonstrate to the Office of Management and Budget
that acquiring the base stations and related equipment would be more
cost-effective than using base stations owned or operated by other
federal agencies.\7


--------------------
\7 This requirement should not apply to DGPSs undergoing research and
development or operational testing. 


   AGENCY COMMENTS
------------------------------------------------------------ Letter :8

As requested, we did not obtain official agency comments on a draft
of this report.  However, we did discuss the results of our review
with officials of DOD, DOT, the Corps of Engineers, BLM, Forest
Service, the U.S.  Geological Survey, NOAA, EPA, OMB, and the U.S. 
Industry Council for Global Positioning Systems.  Generally, DOT
officials (such as the Acting Director, Radionavigation and
Positioning Staff, Office of the Assistant Secretary for
Transportation Policy) agreed with our recommendations concerning the
need for a stronger mechanism to coordinate federal DGPS activities. 
They believed the structure proposed by the DOD-DOT task force could
bring about better coordination but acknowledged that the proposed
structure lacked authority over non-DOT agencies.  Officials at OMB
with oversight responsibility over transportation and natural
resource agencies agreed action by OMB was needed to develop a
stronger coordinative mechanism for federal DGPS activities.  They
indicated they were considering various options for how best to
coordinate these activities, including our recommendation regarding
future justification of DGPS budget requests.  Officials of all other
agencies reviewed--including the Chair, Federal Geodetic Control
Subcommittee, Federal Geographic Data Committee--agreed with our
conclusions and recommendations.  Where appropriate, we have
incorporated changes suggested by agency officials to clarify the
report. 


---------------------------------------------------------- Letter :8.1

We conducted our review between August 1993 and August 1994 and
performed the work in accordance with generally accepted government
auditing standards.  See app.  II for a discussion of our scope and
methodology. 

As arranged with your offices, unless you publicly announce its
contents earlier, we plan no further distribution of this report
until 30 days after the date of this letter.  At that time, we will
send copies of this report to the heads of pertinent federal
departments and agencies, industry representatives, and other
interested parties.  Copies will be available to others upon request. 

If you or your staff have any questions about our review, I can be
reached at (202) 512-2834.  Major contributors are listed in app. 
III. 

Kenneth M.  Mead
Director, Transportation and
 Telecommunication Issues


FEDERAL AGENCY DGPS APPLICATIONS
=========================================================== Appendix I

Nine of the 13 federal agencies contacted were designing,
implementing, or operating differential global positioning systems
(DGPS) for various applications.\1 These applications included
navigation, surveying/mapping, and other uses.  Table I.1 provides a
brief description of these activities. 



                Table I.1 Federal Agency DGPS
                         Applications


                       Actual
                     as of 3/  Planned\  Principal DGPS
Federal agency          31/94         b  application
-------------------  --------  --------  -------------------
Forest Service             26         0  Resource management
                                          activities, such
                                          as mapping and
                                          surveying property
                                          corners, roads,
                                          trails, and water
                                          resources
Federal Aviation            0       734  Aviation
 Administration                           navigation,
                                          including enroute
                                          flights, terminal
                                          activity, and
                                          precision and
                                          nonprecision
                                          landing approaches
Environmental               4         1  Environmental
 Protection Agency                        monitoring, such
                                          as surveying and
                                          mapping landfills,
                                          wells, outfalls,
                                          and other
                                          facilities
U.S. Coast Guard            8        55  Marine navigation,
                                          including harbor
                                          and harbor
                                          approaches
Bureau of Land             16        11  Land management
 Management                               activities,
                                          including
                                          surveying and
                                          mapping property
                                          corners, gathering
                                          geographic data,
                                          and suppressing
                                          fires
National Oceanic            3         2  Surveying and
 and Atmospheric                          mapping U.S.
 Administration                           continental waters
                                          and gathering
                                          spatial data for
                                          geographic
                                          applications
Army Corps of              17        19  Dredging and buoy
 Engineers                                placement
                                          activities
U.S. Geological             2         0  Earthquake fault
 Survey                                   movement detection
St. Lawrence Seaway         1         0  Buoy placement
 Development
 Corporation
------------------------------------------------------------
\a Includes only permanent DGPS base stations--that is, equipment and
facilities that are in one place for 6 months or longer. 

\b Fiscal years 1994-96. 

Among the 13 agencies contacted, the Federal Aviation Administration
(FAA) and the Coast Guard are undertaking the largest DGPS networks. 
Their networks will not only provide DGPS coverage for air and marine
applications but also will be used by other agencies for surveying,
mapping, and other applications.  The FAA and Coast Guard DGPS
networks are briefly described below. 


--------------------
\1 The remaining four federal agencies did not own or operate DGPS
base stations.  These agencies were the Federal Transit
Administration, the Federal Highway Administration, the Federal
Railroad Administration, and the Department of Defense (DOD). 
However, the Federal Transit Administration and the Federal Highway
Administration provide funding to state and local authorities, and
this funding may support DGPS base stations at the state or local
levels.  A DOD official said that DOD does not use DGPS technology
for military operations. 


   FAA DGPS NETWORK
--------------------------------------------------------- Appendix I:1

FAA's planned system consists of two main parts--a wide-area network
covering the entire country and a local-area DGPS to provide more
accurate positioning information needed for landings at major
airports.  By 1998, FAA plans to establish its Wide-Area Augmentation
System.  The system will augment the integrity, availability and
accuracy of the basic global positioning system signals so the
augmented system can be used as the primary means of navigation for
all phases of flight except those requiring higher accuracies (i.e.,
Category II/III precision approaches).  FAA estimates that equipment
needed for the wide-area system will cost about $500 million. 

The wide-area system will contain up to 33 base stations.  Each base
station will be composed of a primary unit and two backups to provide
a high degree of reliability through redundancy.  Base stations will
collect positioning data from global positioning system satellites
and communicate these data to up to six master control stations.  In
turn, the master control station will transmit the DGPS correctional
information to up to nine geostationary satellites for broadcasting. 
According to FAA officials, this system will provide horizonal
accuracies of about 3 meters and vertical accuracies of about 5
meters throughout the United States.  To provide continuous
navigational integrity, the system is designed to be available 99.999
percent of the time and provide notification of a bad signal within 6
seconds.  Each base station will also be able to provide DGPS data to
other federal users for post-processing applications such as
surveying and mapping. 

For its local-area system, FAA also plans to have up to 701\2

DGPS base stations to provide greater positioning accuracies for
Category I, II and III precision landings at airports.  An FAA
official estimated that it would cost about $1 million for each of
these local area systems, but the cost of such equipment would be
financed by the local airport authority. 


--------------------
\2 According to an FAA official, the total number of base stations
for the local-area DGPS at major airports could be considerably less
if national security policy permits the Wide Area Augmentation System
to generate navigation signals accurate enough to support Category I
precision approaches. 


   COAST GUARD DGPS NETWORK
--------------------------------------------------------- Appendix I:2

To provide electronic aids to navigation for maritime commerce in the
United States, the Coast Guard plans to install DGPS base stations at
49 sites along the coastal United States, the Great Lakes, Puerto
Rico, Alaska, and Hawaii.  Fourteen additional DGPS sites are planned
for the Mississippi and Ohio River valleys.  These additional base
stations will be jointly operated with the Army Corps of Engineers. 
(See fig.  II.I for DGPS coverage areas in the continental United
States).  The Coast Guard will also explore the possibility of
providing additional DGPS coverage for all inland waterways. 

   Figure II.1:  Location and
   Coverage Provided by Coast
   Guard and Army Corps of
   Engineer DGPS Base Stations

   (See figure in printed
   edition.)

   Note:  This map is based on
   Coast Guard data as of July
   1994.  Not included is DGPS
   coverage for Alaska, Hawaii,
   and Puerto Rico.

   (See figure in printed
   edition.)

The Coast Guard's DGPS network was designed to provide accuracies of
8 to 20 meters for harbor approach and harbor navigation.  However,
subsequent refinements have produced accuracies to 3 meters in
real-time, which can be used for river and harbor hydrographic
surveying.  Other Coast Guard uses of DGPS include positioning buoys
and aids to navigation and monitoring and controlling port traffic as
part of the Coast Guard's Vessel Traffic Services. 

Equipment at each Coast Guard DGPS site will include a dual frequency
receiver to record positioning information from global positioning
system satellites.  In turn, the base stations will broadcast
corrected signals via radiobeacons to marine users.  DGPS data will
also be stored on computers and made available to federal agencies or
the public for such post-processing applications as mapping and
surveying.\3 A second DGPS base station will be located at each site
and will monitor system accuracy and integrity via continuous
integrity checks.  A communication link between all stations will
allow remote monitoring by one West Coast and one East Coast regional
DGPS control station, which will be monitored 24 hours a day.  The
control stations will also automatically record and archive all DGPS
data as well as assess the system's ability to meet operational
performance requirements, detect system anomalies, and provide a
record of operational conditions at all stations.  The control
stations will also allow control of the DGPS system by the national
command authority in the event of a national emergency. 

Coast Guard DGPS equipment costs are estimated at $17.8 million. 
Operations and maintenance costs are estimated at $5 million
annually.  The DGPS network will have an expected useful life of 25
years. 


--------------------
\3 In a May 1994 memorandum of agreement, the Coast Guard and the
Coast and Geodetic Survey, National Oceanic and Atmospheric
Administration, Department of Commerce agreed to cooperate in making
DGPS data available to federal and other DGPS users in formats
suitable for surveying and mapping.  Under the agreement, the
National Geodetic Survey would acquire and operate whatever computer
and communication equipment is needed to provide public access to the
DGPS data. 


SCOPE AND METHODOLOGY
========================================================== Appendix II

We reviewed both existing and planned DGPS equipment, facilities, and
operating policies and procedures with 13 federal agencies.  This
included six agencies within the Department of Transportation:  the
FAA, Federal Highway Administration, Federal Railroad Administration,
Federal Transit Administration, U.S.  Coast Guard, and St.  Lawrence
Seaway Development Corporation.  Other agencies reviewed included the
Bureau of Land Management, U.S.  Forest Service, U.S.  Geological
Survey, National Oceanic and Atmospheric Administration,
Environmental Protection Agency, Army Corps of Engineers, and
Department of Defense.  We selected these 13 agencies to obtain
diversity in the size and type of existing or planned navigation or
surveying/mapping DGPS applications. 

At each agency we interviewed officials responsible for designing and
implementing DGPS applications and obtained any documents, studies,
or reports related to existing or planned DGPS equipment, facilities,
or applications.  To identify existing and planned DGPS equipment and
facilities at field office locations, we contacted agency personnel
in selected regional offices of the Bureau of Land Management,
Environmental Protection Agency, Forest Service, U.S.  Geological
Survey, and Army Corps of Engineers. 

To determine efforts to coordinate federal DGPS applications, we
interviewed federal officials responsible for directing the
activities of the U.S.  Coast Guard's Global Positioning System
Information Center and the Civil Global Positioning System Service
Interface Committee.  We discussed DGPS coordination with the
Executive Secretariat of the Federal Geographic Data Committee; the
Chair of the Federal Geodetic Control Subcommittee; and the Chair of
the Fixed Reference Station Working Group, Geodetic Control
Subcommittee, Federal Geographic Data Committee.  We also discussed
federal agency DGPS activities with the Executive Secretary and the
Executive Director for Policy of the U.S.  Global Positioning System
Industry Council, and we met with Department of Transportation
representatives to the joint Department of Defense-Department of
Transportation Task Force.  We also attended the Institute of
Navigation's Satellite Division GPS-93 Conference and the 22nd
meeting of the Coast Guard Global Positioning System Civil Interface
Committee, both held in Salt Lake City, Utah, in September 1993. 

Finally, on the basis of our work at the above locations, we
developed a list of DGPS experts with whom we discussed federal
agency DGPS activities and additional steps that may be needed to
enhance joint development or sharing of federal DGPS facilities.  We
selected these experts on the basis of their knowledge, experience,
and familiarity with existing and planned federal agency DGPS systems
and applications. 



                          Table II.1
           
                List of DGPS Experts Contacted

Agency/
organization        Name/title          DGPS expertise
------------------  ------------------  --------------------
Environmental       Brenda Groskinsky,  Responsible for
Protection Agency   Environmental       research and
                    Scientist           development for DGPS
                                        environmental
                                        monitoring
                                        applications

Headquarters, U.S.  William A.          Responsible for
Army Corps of       Bergen,             coordinating Corps'
Engineers           Civil Engineer      surveying and
                                        mapping activities

U.S. Army Corp of   Sally Frodge,       Conducting a study
Engineers,          Geodesist           on the feasibility
Topographic                             of a national DGPS
Engineering Center                      network

Trimble             Dr. Peter Loomis,   Involved in DGPS
Navigation, Ltd.    Staff Scientist     research for 9 years

National Oceanic    William Strange,    Chairman, Fixed
and Atmospheric     Chief Geodesist     Reference Station
Administration                          Working Group,
                                        Federal Geodetic
                                        Control Subcommittee

FAA Mitre           Robert Loh,         Involved with
Corporation         Wide-Area DGPS      aviation GPS and
                    Program Manager     DGPS research for
                                        more than 11 years

FAA                 Joseph Dorfler,     Many years of
                    Satellite Program   experience with
                    Manager             aviation engineering
                                        and research

U.S. Coast Guard    Joseph W.           Involved in GPS
                    Spalding,           research for 8 years
                    Project Manager,
                    Research and
                    Development Center

U.S. Coast Guard    Cmdr. Doug Alsip,   Project manager for
                    Chief,              the Coast Guard's
                    Radionavigation     DGPS network
                    and Development
                    Branch

U.S. Geological     Larry Hothem,       Responsible for
Survey              GPS Research and    implementing GPS
                    Applications        technology into
                    Manager             agency earth science
                                        programs

U.S. Global         Mike Swiek,         Since 1991, the U.S.
Positioning System  Executive           Global Positioning
Industry Council    Secretary           System Industry
                                        Council has been
                    Ann Ciganer,        active in addressing
                    Executive           the regulatory,
                    Director, Policy    political, and
                    and Government      technical issues
                    Affairs Liaison,    facing the global
                    Trimble Navigation  positioning system
                                        industry.

U.S. Forest         Anthony             Since 1988, has been
Service             Jasumback,          responsible for all
                    Global Positioning  Forest Service DGPS
                    System Program      test and evaluation
                    Leader, Missoula    activities
                    Technology and
                    Development Center
------------------------------------------------------------

MAJOR CONTRIBUTORS TO THIS REPORT
========================================================= Appendix III

RESOURCES, COMMUNITY, AND ECONOMIC
DEVELOPMENT DIVISION,
WASHINGTON, D.  C. 

Allen Li

SEATTLE REGIONAL OFFICE

Brian A.  Estes
Stanley G.  Stenersen
Ronald E.  Thompson
Randall B.  Williamson
Gary E.  Ziebarth

