AIR FORCE SPACE COMMAND

CAPSTONE REQUIREMENTS DOCUMENT

FOR

GLOBAL POSITION, VELOCITY, AND TIME DETERMINATION CAPABILITY

![](media/image1.emf)

18 JULYN 1997

Supersedes: 23 JUNE 1997

**DRAFT**

**Not for Implementation or Compliance**

> OPR: HQ AFSPC/DR
>
> Phone: Comm (719) 554-5720
>
> DSN 692-5720

TABLE OF CONTENTS

1\. GENERAL DESCRIPTION OF OPERATIONAL CAPABILITY

1.1 INTRODUCTION

1.1.1 The Global Position, Velocity, and Timing Determination

1.1.2 Presidential Decision Directive

1.2 PURPOSE

1.3 SCOPE AND PROCESS

1.3.1 Scope

1.3.2 Process

1.4 PVT BACKGROUND AND GUIDANCE

1.4.1 Position, Velocity, and Timing Descriptions

1.4.2 National Guidance on PVT

1.4.3 DoD Guidance on PVT

1.4.4 Significant Studies and Reports

1.5 OPERATIONAL CONCEPT

1.5.1 Scope

1.5.2 Military Operational Concepts

1.5.3 Use of Foreign PVT Systems.

1.5.4 Space Exploitation Operational Concept.

1.5.5 Concept of Operations for Civil Applications

1.5.6 Future PVT Operations Concept

1.6 PVT MISSION AREAS AND MISSION NEEDS

1.6.1 PVT Mission Areas for DoD

1.6.2 PVT Mission Areas for Other Federal Agencies.

1.6.3 Mission Areas for Other Entities

1.6.4 Mission Needs

1.7 REQUIREMENTS ALLOCATION

1.8 DESCRIPTION OF REQUIRED CHARACTERISTICS

2\. RESERVED

2\.

3\. SHORTCOMINGS OF EXISTING SYSTEMS

3.1 INTRODUCTION

3.2 EXISTING AND PROJECTED SYSTEMS DESCRIPTION

3.2.1 Ground Controlled Approach/Precision Approach Radar

3.2.2 Global Positioning System

3.2.3 Instrument Landing System

3.2.4 Inertial Navigation Systems

3.2.5 Long Range Navigation

3.2.6 Microwave Landing System

3.2.7 Radiobeacons

3.2.8 Omega

3.2.9 Very High Frequency Omnidirectional Range/Distance Measuring
Equipment

3.2.10 Tactical Air Navigation

3.2.11 GPS Wide Area Augmentation System

3.2.12 GPS Local Area Augmentation System

3.3 LIMITATIONS OF CURRENT SYSTEMS

3.4 POSITION ACCURACY

3.4.1 Shortcomings

3.4.2 Impact

3.5 VELOCITY ACCURACY

3.5.1 Shortcomings

3.5.2 Impact

3.6 TIMING ACCURACY

3.6.1 Shortcomings

3.6.2 Impact

3.7 INTEGRITY

3.7.1 Shortcomings

3.7.2 Impact

3.8 AVAILABILITY

3.8.1 Shortcomings

3.8.2 Impact

3.9 SECURITY

3.9.1 Shortcomings

3.9.2 Impact

3.10 CONTINUITY OF SERVICE

3.10.1 Shortcomings

3.10.2 Impact

3.11 COVERAGE

3.11.1 Shortcomings

3.11.2 Impact

3.12 SUPPORTABILITY

3.12.1 Shortcomings

3.12.2 Impact

3.13 SURVIVABILITY

3.13.1 Shortcomings

3.13.2 Impact

3.14 INTEROPERABILITY

3.14.1 Shortcomings

3.14.2 Impact

4\. REQUIRED CHARACTERISTICS

4.1 INTRODUCTION

4.1.1 Required System Characteristics

4.1.2 Unconstrained Requirements

4.1.3 Parameters

4.1.4 Phases of Navigation

4.1.5 Military Requirements

4.1.6 Multiple Characteristics

4.1.7 Organization

4.2 POSITION ACCURACY

4.2.1 Definition

4.2.2 Requirements

4.2.3 Rationale.

4.3 VELOCITY ACCURACY

4.3.1 Definition

4.3.2 Requirements

4.3.3 Rationale

4.4 TIMING ACCURACY

4.4.1 Definition

4.4.2 Requirements

4.4.3 Rationale

4.5 INTEGRITY

4.5.1 Definitions

4.5.2 Requirements

4.5.3 Rationale

4.6 AVAILABILITY

4.6.1 Definition

4.6.2 Requirements

4.6.3 Rationale

4.7 SECURITY

4.7.1 Definition

4.7.2 Requirements

4.7.3 Rationale

4.8 CONTINUITY OF SERVICE

4.8.1 Definitions

4.8.2 Requirements

4.8.3 Rationale

4.9 AFFORDABILITY

4.9.1 Definition

4.9.2 Requirements

4.9.3 Rationale.

4.10 COVERAGE

4.10.1 Definition

4.10.2 Requirements

4.10.3 Rationale.

4.11 SUPPORTABILITY

4.11.1 Definition

4.11.2 Requirements

4.11.3 Rationale.

4.12 SURVIVABILITY

4.12.1 Definition

4.12.2 Requirements

4.12.3 Rationale.

4.13 INTEROPERABILITY

4.13.1 Definition

4.13.2 Requirements

4.13.3 Rationale

4.14 RECOMMENDED KEY PERFORMANCE PARAMETERS

4.15 TRANSITION ISSUES

4.15.1 Continuity of Operations

4.15.2 Backward Compatibility

4.15.3 Force Structure

APPENDIX A POSITION, VELOCITY, AND TIME REQUIREMENTS A-1

APPENDIX B ACRONYMS AND ABBREVIATIONS B-1

APPENDIX C GLOSSARY C-1

APPENDIX D REFERENCES D-1

APPENDIX E OTHER PVT SYSTEMS E-1

APPENDIX F PVT SYSTEM GRADING RATIONALE F-1

**SECTION 1**

# GENERAL DESCRIPTION OF OPERATIONAL CAPABILITY

## INTRODUCTION

### The Global Position, Velocity, and Timing Determination

The capability to precisely determine position, velocity, and time (PVT)
is extremely valuable for military missions and civil and commercial
applications. Globally, such systems include the Global Positioning
System (GPS), air traffic control facilities, aviation and maritime
navigation aids, various precise time distribution systems, and many
others. Although there are foreign systems that provide PVT information
to United States (US) military and civil users, such systems will not be
relied upon for military operations. Because of its national and
international importance, as well as pervasive use, policies and
guidance with respect to the GPS provide a foundation for defining
overall requirements. Requirements are stated in terms of performance
and no particular solution, either ground-based or space-based, is
recommended or implied.

### Presidential Decision Directive 

The combination of individual ground-based and space-based systems that
provide PVT services to military and civil users can be viewed as a
global PVT "system of systems". Although many widely dispersed systems
provide PVT services, GPS has emerged as the dominant element of this
global system of systems. Recognizing this, in March 1996, the President
approved a comprehensive national policy, the Presidential Decision
Directive (PDD) on the management and use of GPS, "US Global Positioning
System Policy," (National Science and Technology Council-6 (NSTC)-6)).
This policy presents a strategic vision for management and use of GPS,
addressing a broad range of military, civil, commercial and scientific
interests, both national and international.

#### [Goals of the]{.underline} [PDD]{.underline}. The directive states US goals as follows:

a\. Strengthen and maintain our national security.

b\. Encourage acceptance and integration of GPS into peaceful civil,
commercial and scientific applications worldwide.

c\. Encourage private sector investment in and use of US GPS
technologies and services.

d\. Promote safety and efficiency in transportation and other fields.

e\. Promote international cooperation in using GPS for peaceful
purposes.

f\. Advance US scientific and technical capabilities.

#### [PDD Policy Guidelines]{.underline}. Within these broad goals, the PDD established the following policy guidelines:

a\. We will continue to provide the GPS Standard Positioning Service
(SPS) for peaceful civil, commercial, and scientific use on a
continuous, worldwide basis free of direct user fees.

b\. It is our intention to discontinue the use of Selective Availability
(SA) within a decade in a manner that allows adequate time and resources
for our military forces to prepare fully for operations without SA. To
support such a decision, affected departments and agencies will submit
recommendations in accordance with the reporting requirements outlined
in this directive.

c\. The GPS and US Government (USG) augmentations will remain responsive
to the National Command Authorities.

d\. We will cooperate with other governments and international
organizations to insure an appropriate balance between the requirements
of international civil, commercial, and scientific users and
international security interests.

e\. We will advocate the acceptance of GPS and USG augmentations as
standards for international use.

f\. To the fullest extent possible, we will purchase commercially
available GPS products and services that meet USG requirements and will
not conduct activities that preclude or deter commercial GPS activities,
except for national security or public safety reasons.

g\. A permanent interagency GPS Executive Board (IGEB), jointly chaired
by the Department of Defense (DoD) and Department of Transportation
(DOT), will manage the GPS and US Government augmentations. Other
departments and agencies will participate as appropriate. The IGEB will
consult with USG agencies, US industries and foreign governments
involved in navigation and positioning system research, development,
operation and use.

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## PURPOSE

This capstone requirements document (CRD) responds to the National
objectives and policy guidelines detailed in the PDD and consolidates
military and civil needs for PVT services. These requirements reflect
the USG vision of an overarching PVT capability for applications in
national security, space operations, space exploration, safety,
communications, transportation, environmental sensing, and other areas.

The CRD will be used as a basis for development of military and civil
system-specific operational requirements documents (ORDs) for specific
applications. This CRD consolidates requirements from military
departments, civil departments, and commercial interests. For the DoD,
it is a bridge between multiple mission need statements (MNS) and
Service ORDs. For the civil communities (government and private), it is
a bridge between strategic plans and individual system specifications.
The CRD is also intended to be used as a source document for developing
future worldwide PVT system architecture alternatives.

## SCOPE AND PROCESS

### Scope

This CRD contains performance-based requirements for development of
future PVT systems. Requirements gathered to date have been for
near-term and mid-term needs. Far-term military requirements will be
addressed in the mission area planning process. Requirements are
categorized according to the physical realm in which the user will
operate: subsurface (underwater and underground), surface, air, and
space.

### Process

Requirements changes may occur because of changes in missions, threats,
operations concepts, new technologies, or emerging requirements. The
source of changes may be military users, civil customers, or inputs from
the scientific or commercial communities. When requirements change, the
CRD will be updated.

Air Force Space Command (AFSPC) led the effort to develop the CRD. As
approved/validated requirements documents, AFSPC used the Chairman,
Joints Chiefs of Staff (CJCS) Master Navigation Plan (MNP) and the
Federal Radionavigation Plan (FRP) as the major source documents.
Applicable MNS and ORD were also used as source documents. In addition,
AFSPC solicited and collected requirements from the military services.
The DOT solicited and collected requirements from the government,
scientific, commercial and other civil communities. As shown in Figure
1-1, Air Force Materiel Command's Space and Missile Systems Center
(SMC), using the CRD, is developing an acquisition master plan (AMP) for
GPS modernization that will address GPS-based (i.e., GPS and GPS
augmentations, or other systems for which GPS is the primary source of
PVT information) solutions to the requirements articulated in the CRD.
The process by which those required capabilities that cannot be
satisfied by the GPS-based architecture defined in the AMP is to be
determined Concepts will be developed, trade-off analyses conducted, and
affordability considerations incorporated. The optimal architecture will
be recommended to the Joint Space Management Board (JSMB). Concurrently,
the Joint Requirements Oversight Council (JROC) will validate DoD
requirements. The final architecture will address military and civil
applications and will be approved by the IGEB.

![](media/image3.emf){width="5.684027777777778in"
height="3.634027777777778in"}

Figure 1-1. Capstone Requirements Document Development Process

The CRD and PVT system architecture will undergo periodic review,
revision, and revalidation as shown in Figure 1-2. Costs, benefits, and
implementation issues of proposed architectures will be identified by
trade-off studies. Affected users of the PVT systems will provide input
on the new requirements and architecture. The DoD Space Architect, as
well as the IGEB, will review the CRD. The JROC will validate all new or
modified military requirements. The JSMB has oversight responsibility
for military space-based architectures. Funding needed for the selected
architecture will be addressed in the DoD Planning, Programming, and
Budgeting System (PPBS) and modifications to acquisition plans. As
designated in the PDD, the IGEB has overall responsibility for managing
GPS and its US augmentations, and will be the final approval authority
for all significant changes to the architecture.

Figure 1-2. CRD Update and Review Process

## PVT BACKGROUND AND GUIDANCE

### Position, Velocity, and Timing Descriptions

1.4.1.1 [Position]{.underline}. Position is defined in Webster's Ninth
New Collegiate Dictionary as the point or area occupied by a physical
object. The objective of the position determination capability is to
improve the effectiveness of military and civil missions and activities
by enhancing their ability to precisely determine their position below,
on or above the surface of the earth 24 hours a day. Positioning
provides information on the user's location relative to a specific
geospatial reference coordinate system at an accurately specified time.
User equipment tailored to specific applications determines the user
location in the appropriate format. Augmented processing of PVT position
information or supplementary information may be necessary to meet the
required accuracies.

1.4.1.2 [Velocity]{.underline}. Velocity is defined by Webster as the
time rate of linear motion in a given direction. The objective of the
velocity determination capability is to improve the effectiveness of
military, civil, and commercial missions and activities by enhancing
their ability to safely and effectively navigate worldwide, 24 hours a
day. Velocity is a derived capability determined by measuring the
Doppler shift of a signal.

1.4.1.3 [Timing]{.underline}. Time is a quantity used to specify the
order in which events occurred and measure the amount by which one event
preceded or followed another(Ref 42). Joint Publication 1-02, DoD
Dictionary of Military and Associated Terms, defines time as the
designation of an instant on a selected time scale, astronomical or
atomic. Timing services, with varying degrees of precision, are required
by numerous military and civil systems in support of many critical
missions. Internationally, coordinated universal time, abbreviated UTC,
is maintained by the Bureau International des Poids et Mesures, Sevres,
France. The precise time reference for US military systems is UTC as
determined by the United States Naval Observatory Master Clock (UTC
\[USNO\]). Several systems are used for distribution of UTC (USNO),
including GPS. Maintenance of time interval (precise frequency) is the
responsibility of the National Institute of Standards and Technology.
Timing is a combination of precise time and time interval.

###  National Guidance on PVT

In addition to the PDD previously discussed, a White House commission
report, recent laws, executive direction, and Federal plans provide a
foundation for many of the requirements identified in this document.

1.4.2.1 [White House Commission on Aviation Safety and
Security]{.underline}. In another important initiative that
significantly affects the global PVT system, this Commission, chaired by
Vice President Gore, recommended the following GPS actions in its final
report to the President:

-   The US must provide stronger strategic leadership for civil uses of
    GPS.

-   Strong civilian participation is required in GPS planning and
    decision making.

-   A Civil GPS Users Advisory Council should be established.

-   Greater redundancy is needed to enhance the ability of users to
    cross-check GPS accuracy and verify the system's reliability.

-   The GPS Executive Board should resolve the remaining issues over
    funding and frequency assignment for a second civil frequency.

-   The Federal Aviation Administration's (FAA) Wide Area Augmentation
    System (WAAS) requires two frequencies to meet civil accuracy needs.

-   The GPS system must be protected from both intentional and
    unintentional interference.

-   The FAA should identify and justify, by July 1997, the frequency
    spectrum necessary for the transition to a modernized air traffic
    control system.

-   To ensure the FAA's spectrum needs during modernization are not
    compromised, the commission recommends that the FAA complete a full
    justification, NLT July 1997, as well as a plan for freeing up
    spectrum as older systems are modernized or decommissioned.

-   The US Government should ensure the accuracy, availability and
    reliability of the GPS system to accelerate its use in National Air
    Space modernization and to encourage its acceptance as an
    international standard for aviation.

1.4.2.2 [Public Law 103-160]{.underline}. Public Law 103-160 (referred
to as GPS 2000) directs that after 30 September, 2000, funds may not be
obligated to modify or procure any DoD platforms that are not equipped
with a GPS receiver. In compliance with this law, GPS receivers are
scheduled to be installed in most military platforms by end of Fiscal
Year (FY) 2000.

1.4.2.3 [The Federal Radionavigation Plan]{.underline}. The 1994 FRP
delineates policies and plans for Federally-provided radionavigation
services. This plan describes areas of authority and responsibility and
provides a management structure by which the individual operating
agencies can define and meet radionavigation requirements in a
cost-effective manner. The FRP identifies military, space, civil air,
civil marine, and civil land radionavigation requirements. It is the
official source of radionavigation policy and planning for the Federal
Government. The document is published jointly by the DoD and the DOT).
The most current edition ws published in 1995. A new version is in draft
form.

### DoD Guidance on PVT

The CJCS approved the most recent MNP in 1994 (CJCS Instruction
6130.01). This plan, currently under revision, implements DoD
Positioning and Navigation (POS/NAV) policy, validates military
positioning/navigation requirements, compares requirements to existing
technology, identifies performance shortfalls, highlights needed
research and development, and provides long-term projections of
anticipated capabilities. It serves as the basis for the Services and
DoD agencies for programming and budgeting for positioning/navigation
systems. This plan is the DoD input to the FRP and appropriate North
Atlantic Treaty Organization plans.

### Significant Studies and Reports

Explosive growth in commercial and scientific use of GPS has brought
this PVT system to the forefront. More efficient land, sea, and air
transportation programs have been enabled by using GPS in conjunction
with expanding communication technologies. In addition, the number and
types of other innovative applications has rapidly increased. As a
result, numerous studies and reports have been done with respect to
future plans for GPS and its augmentations. Several long-range military
studies also have been published emphasizing the essentiality of
accurate and reliable PVT information to win future wars. Some of the
most significant of these are discussed below. Additional references are
listed in Appendix D.

1.4.4.1 [Joint Vision 2010]{.underline}. Published by the Organization
of the Joint Chiefs of Staff in 1997. This vision of future warfighting
embodies the improved intelligence and command and control available in
the information age. The document goes on to develop four operational
concepts: dominant maneuver, precision engagement, full dimensional
protection, and focused logistics. It creates a template to guide the
transformation of these concepts into joint operational capabilities.
With respect to PVT capabilities in the 21^st^ Century, the document
specifically discusses the high value of "knowledge of the precise
location of dispersed friendly forces" and "precision engagement" to
"enable greater discrimination in the application of force."

1.4.4.2 [The "Global Positioning System, Charting the Future"
Study]{.underline}. This is an independent committee's report, published
May 1995, under the joint auspices of the National Academy of Public
Administration and the National Research Council. The report addresses
the future management and funding of the GPS program as mandated by the
National Defense Authorization Act for FY 1994. Key areas for GPS
(commercial, civil, government, and international) were examined as well
as paramount national security interests.

1.4.4.3 "[A Technical Report to the Secretary of Transportation on a
National Approach to Augmented GPS Service"]{.underline}. This report
contained the findings of a joint Department of Transportation and
Department of Commerce study published in December 1994. The study
evaluated the capabilities of various means of GPS augmentation and
recommended the optimum integrated system for meeting the requirements
of Federal land, marine, aviation, and space users.

1.4.4.4 "[The Global Positioning System: Assessing National
Policies,"]{.underline} 1995. This report documents a Rand Corporation
Study. The study identifies opportunities and vulnerabilities for US
interests caused by GPS. It also makes policy recommendations.

1.4.4.5 [Spacecast 2020,]{.underline} June, 1994, Air University. This
study identified capabilities for the period 2020 and beyond and the
enabling technologies that will support the security interests of the
US.

1.4.4.6 [Air Force 2025, "America's Vigilant Edge",]{.underline} Air
University, 1996. Directed by the Chief of Staff, USAF, this study looks
30 years into the future to identify the concepts, capabilities and
technologies the US will require to remain the dominant air and space
force in the 21st century.

1.4.4.7 [New World Vistas]{.underline} [Air and Space Power for the
21st]{.underline} [Century]{.underline}, Space Applications Volume,
Science Advisory Board, December, 1995. This report emphasizes the
long-term military need for highly accurate positioning and time
transfer capabilities.

## OPERATIONAL CONCEPT

### Scope

The operations concept describes how an operational capability,
consisting of a system-of-systems, may be employed. This section
describes the military, GPS, protection and prevention, space, and civil
PVT operations concepts. It closes with a discussion of future PVT
systems operations concepts.

### Military Operational Concepts

In accordance with National Military Strategy and Joint Vision 2010, the
operational objective for the US Military is to achieve overwhelming
effect in a compressed time to win future conflicts quickly, decisively,
and with few casualties. This will be achieved through domination of the
adversary by outmaneuvering enemy forces and destroying them with
precise, concentrated firepower. US forces will seek to control the
extent and pace of the battle, while also disrupting the adversary's
decision cycle. Furthermore, US forces are often called upon to execute
other operations in the lower end of the spectrum of conflict that range
from humanitarian assistance to peace-keeping and peace making. To
achieve these objectives, it is necessary to orchestrate and synchronize
a complex set of sensors; forces; precision weapons; command, control,
communications, computers, and intelligence (C4I); and information
warfare (IW) capabilities within the tactical and strategic
battlespaces. PVT information is absolutely critical to this concept.
Without highly capable and protected PVT, complex battlespace
interactions and weapons delivery cannot be executed. PVT systems
provide essential force enhancement capabilities to several warfighting
functions as shown in Table 1-1. The functions were adapted from the
Universal Joint Task List, Version 3.0, CJCSM 3500.04A, 13 September,
1996.

1.5.2.1 [PVT Operations Concept]{.underline}. The worldwide multiplicity
of uses of PVT systems requires a highly accurate capability that is
available to all users. Future PVT systems will provide position
accuracy, velocity accuracy, and timing accuracy that meets the most
stringent requirements for all users. The PVT systems will meet all but
the most stringent integrity, availability, and continuity of service
requirements without augmentation. Military and civil demands for PVT
availability, accuracy, and coverage are expected to continue to
increase. As recommended in the Gore Report, the US will gradually
transition from dependence upon ground-based navigation aids. GPS meets
or exceeds the accuracy, availability and coverage of many other
radionavigation systems. Consequently, as the full civil potential of
GPS is realized the Federal Government expects to phase out
radionavigation systems that no longer will be required. See Section 3
for a detailed discussion of current systems capabilities, phaseout
dates, etc.

PVT information will be needed by US and allied forces in stressed
environments, including electronic jamming. Hostile forces must not be
able to use PVT capabilities or any augmentations in any area of
responsibility (AOR) in which US and allied forces operate The civil
community will be able to use PVT capabilities outside the specified
AOR.

While PVT systems will provide robust capabilities, the key to effective
use of the system will be embedded user equipment (UE) capabilities. UE
with a wide range of capabilities will be employed. For example, some UE
may be capable of providing highly accurate position information, yet
have no antijam (AJ) capability. New PVT systems will optimize the
performance of existing (legacy) UE.

1.5.2.1.1 [Scenarios]{.underline}.

a\. [Peacetime]{.underline}: All users receive the same service, with
accuracy largely dependent on the capabilities of the UE. Service is
comparable to today's GPS SPS without SA.

b\. [Small Scale Contingency]{.underline}: There would be basically no
change in operation except the US would prevent adversaries in the AOR
from having access to the full precision of the PVT system. There would
be minimal effect on users outside the AOR.

c\. [Major Theater War]{.underline}: The US would prevent adversaries in
the theater from having access to the full precision of the PVT system.
Depending on the threat, the US might also deny theater adversaries any
use of the PVT systems, while ensuring disruptions outside the theater
are minimized. The US would also ensure effects on friendly users near
the theater are minimized. At the same time, friendly users would
continue use of the PVT systems through inherent PVT system interference
resistance and the capability to continue operations while denying use
to adversaries.

Table 1-1: Growing Information Requirements

+-----------------+-------------------------------------+--------------+
| > **Warfighting | **Capabilities Required**           | **PVT        |
| > Functions**   |                                     | Co           |
|                 |                                     | ntribution** |
+-----------------+-------------------------------------+--------------+
| > Command and   | -   Flexible, high capacity Command | Timing       |
| > Control/      |     & Control Networks              |              |
| >               |                                     | Position     |
| > Collaborative | -   Interactive Data Networks and   |              |
| > Planning/     |     Distributed Databases           |              |
| >               |                                     |              |
| > Battle        | -   Video Teleconferencing          |              |
| > Management    |                                     |              |
|                 | -   Maneuver Control and            |              |
|                 |     Situational Awareness           |              |
|                 |                                     |              |
|                 | -   Fratricide Prevention           |              |
+-----------------+-------------------------------------+--------------+
| > Intelligence  | -   Intelligence data collection    | Position     |
|                 |     and dissemination               |              |
|                 |                                     | Position     |
|                 | -   Imagery and related products    |              |
|                 |                                     | Position     |
|                 | -   Terrain Visualization;          |              |
|                 |     Maps-Charts-Geodesy             |              |
|                 |                                     |              |
|                 | -   **High Precision Positioning**  |              |
+-----------------+-------------------------------------+--------------+
| > Precision     | -   **High Precision Navigation**   | Velocity     |
| > Strike        |                                     |              |
|                 | -   Mission data and target/threat  | Position     |
|                 |     updates                         |              |
|                 |                                     | Timing       |
|                 | -   Cooperative Engagement          |              |
|                 |                                     |              |
|                 | -   Remote Operations               |              |
+-----------------+-------------------------------------+--------------+
| > Theater and   | -   Missile Warning                 | Pos          |
| > Strategic     |                                     | ition/Timing |
| >               | -   Reconnaissance, Acquisition,    |              |
| > Warning and   |     Targeting                       | Pos          |
| > Surveillance  |                                     | ition/Timing |
+-----------------+-------------------------------------+--------------+
| > Environmental | -   Weather and oceanographic       | Pos          |
| > Data          |     reports                         | ition/Timing |
|                 |                                     |              |
|                 | -   Other environmental data        |              |
+-----------------+-------------------------------------+--------------+
| > Training and  | -   War-game/simulation; Course of  |              |
| > Planning      |     Action analyses                 |              |
|                 |                                     |              |
|                 | -   Proficiency training and        |              |
|                 |     Mission Rehearsal/Preview       |              |
+-----------------+-------------------------------------+--------------+
| > Sustainment   | -   \"Reachback\" of deployed       | Timing       |
| > support:      |     forces to the sustaining base   |              |
|                 |                                     | Timing       |
| -   Logistics   | -   Telemedicine                    |              |
|                 |                                     | Position     |
| -   Personnel   | -   Distributed Databases and       |              |
|                 |     Networks                        |              |
| -   Finance     |                                     |              |
|                 | -   In-Transit Asset Visibility     |              |
| -   Contracting |                                     |              |
+-----------------+-------------------------------------+--------------+

1.5.2.2 [Protection and Prevention]{.underline} [Operations
Concept]{.underline}. The ability to protect PVT information for
friendly use while preventing it hostile exploitation is critical to
military operations. Recognizing this fact, Congress directed the DoD in
the FY96 Defense Authorization Act, to implement a plan for the
enhancement of GPS that provides for the:

-   Development and acquisition of effective capabilities to prevent
    hostile military forces from using the GPS without hindering the
    ability of US military forces and for civil users to have access to
    and use of the system.

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-   Development and acquisition of receivers for the GPS and other
    techniques for weapons and weapon systems that provide substantially
    improved resistance to jamming and other forms of electronic
    interference or disruption.

In addition, the PDD discussed earlier stated that the DoD will "develop
measures to prevent the hostile use of GPS and its augmentations to
ensure that the US retains a military advantage without unduly
disrupting or degrading civilian uses."

These directives will be operationally implemented as part of the
protection and prevention initiative. Protection and prevention
operational actions taken to modify satellite modes or signal
characteristics via satellite control will be accomplished by AFSPC.
Protection and prevention actions such as jamming of enemy receivers or
modification to user equipment will be performed by in-theater forces.

###  Use of Foreign PVT Systems. 

US military and civil aircraft use foreign PVT systems on a routine
basis while operating in the air space of foreign countries. This is in
accordance with International Civil Aviation Organization (ICAO) rules
and will continue. These systems are primarily local in their coverage
and are protected by international agreements. Foreign space-based
systems, such as the Russian Global Orbiting Navigation Satellite System
(GLONASS), have much broader coverage and potentially could be used for
a wide variety of PVT needs. In this context, at least for civil
applications, GLONASS could be viewed as "competing" with GPS for
worldwide acceptance and usage. As a practical matter, users may be able
to choose one system over another or even choose a combination of
systems. US policy is to promote GPS as the world standard by committing
to long-range assurance of signal availability and incorporating
improvements as technology and funding permit. Military users may use
foreign systems in planned or opportunistic scenarios, for example, in
an area where the foreign system might offer better coverage. However,
US military users will not rely on foreign systems in a hostile or
potentially hostile environment. A brief description of the major
foreign space-based PVT systems is provided below.

1.5.3.1 [Global Navigation Satellite System]{.underline}. GLONASS
provides navigation information primarily for maritime and air
navigation, although its time transfer capabilities are similar to those
of GPS. The system was inaugurated in 1982. About 67 satellites were
launched between 1982 and 1994, apparent evidence that the satellites
suffer a higher attrition rate than GPS satellites. The GLONASS
constellation comprises 24 satellites, eight in each of three orbital
planes, separated by 120 degrees. This configuration allows users access
to at least four satellites.

Each GLONASS satellite transmits two spread spectrum signals in the L
band and operates on, and can be identified by, a different set of
frequencies. The radio frequency (RF) carriers operate between 1240
megahertz (MHz) and 1260 MHz and between 1597 MHz and 1617 MHz. Unlike
GPS, all the GLONASS satellites transmit the same code. The GLONASS
satellites transmit a low precision, narrow band code (similar to GPS
SPS) on the higher transmit frequency and a high precision, broad band
code (similar to GPS precise positioning service (PPS)) on both
frequencies. A low speed (50 Hz) navigation message from each satellite
includes precise ephemeris for that satellite and information about the
onboard clock, as well as almanac data about the other GLONASS
satellites. There is no counterpart to Selective Availability in
GLONASS.

1.5.3.2 [European Geostationary Navigation Overlay Service]{.underline}.
The European Geostationary Navigation Overlay Service (EGNOS) is an
augmentation system for satellite navigation. EGNOS is being jointly
developed by the European Space Agency, the European Commission, and the
European Organisation for the Safety of Air Navigation (EuroControl).
EGNOS will provide civil GPS and GLONASS users with improved accuracy,
integrity, and availability. One transponder will be carried on each of
two INMARSAT-III satellites, located above the equator at 64 degrees
east and 15.5 degrees west longitude. Transponder coverage will include
Europe, Africa, South America, and most of Asia.

EGNOS will provide ranging, integrity, and Wide Area Differential
Services. The ranging service will broadcast GPS-like navigation signals
to help solve the shortfall in GPS/GLONASS satellite visibility. Ranging
service is planned to start in 1997. The integrity service will
broadcast range-error estimates for each GPS, GLONASS, and EGNOS
navigation signal. The integrity service enables users to decide much
sooner whether the signal from a particular navigation satellite is out
of tolerance. The Wide Area Differential Service will broadcast
correction signals to improve the precision of GPS SPS to a precision of
five to ten meters. The integrity service and Wide Area Differential
Service will be phased in between 1998 and 2000.

The initial INMARSAT-III transponders will be supplemented at a later
time. Ranging and integrity monitors will be distributed over the
service area and connected with Master Control Centers, where the EGNOS
signal will be generated. (REF 33)

1.5.3.3 [Japanese GPS Service]{.underline}. Japan is developing its own
four satellite GPS augmentation constellation and hopes to have it
operational by 2000. In the meantime, the Japan Civil Aviation Bureau
(JCAB) and the FAA have agreed that a Multi-function Transport Satellite
(MTSAT) will offer WAAS services in the Asian-Pacific region. The MTSAT
will offer air-to-ground communications, WAAS-compatible satellite
navigation services, and meteorological imaging and sensor services. The
first MTSAT is scheduled for launch in 1999. The JCAB plans to offer
leased MTSAT service to countries in the Asian-Pacific area.

(REF 34)

### Space Exploitation Operational Concept.

PVT may be used for space platform (i.e., satellite and space
exploration) navigation by providing a means for ephemeris
determination, attitude determination, and time transfer. This use of
PVT is expected to increase in the future, both in numbers of platforms
and orbital altitudes, from low earth orbit to geosynchronous.
Space-based applications of PVT are considered "out-of theater" uses and
the impact of protection and prevention actions on such uses must be
accounted for in design of protection and prevention devices.

### Concept of Operations for Civil Applications

The civil, commercial, and scientific sectors have all seen rapid growth
in the use of GPS. Some of the myriad civil uses of GPS are listed in
Table 1-2. The operational concept for these areas is for independent,
distributed users to have free access to the civil PVT signals.
Characteristics of the civil signal will be openly published. Signal
reliability, availability, and integrity will be provided at assured
levels. Determining PVT signal applications is the responsibility of the
user.

Table 1-2: Examples of Civil Uses of GPS

+-----------+-----------+-----------+-----------+-----------+-----------+
| **MAJOR   | **USES**  |           |           |           |           |
| AREA**    |           |           |           |           |           |
+===========+===========+===========+===========+===========+===========+
| **LAW     | -         | -   M     | -         | -         | -         |
| EN        |  Dispatch | onitoring |  Improved |  Tracking |    Border |
| FORCEMENT |     of    |     of    |           |           |     sur   |
| AND       |     a     |     game  | emergency |  movement | veillance |
| SAFETY**  | mbulance, |           |           |     of    |           |
|           |           | preserves |  response |     c     | -   Flood |
|           |    police |     and   |     time  | ontraband |     level |
|           |     and   |           |           |           |     and   |
|           |     fire  | protected | -   M     | -         |           |
|           |     d     |           | onitoring |  Security |    damage |
|           | epartment |   fishing |     of    |     of    |     a     |
|           |           |           |           |     high  | ssessment |
|           | personnel |   grounds |    severe |     g     |           |
|           |     and   |           |           | overnment | -         |
|           |           | -         |   weather |           |  Locating |
|           | equipment | Emergency |           | officials |           |
|           |           |     e     | -         |     and   |  disabled |
|           | -   Ori   | vacuation |  Tracking |     di    |           |
|           | enteering |           | /recovery | gnitaries |  vehicles |
|           | /Personal |  planning |     of    |     while |     for   |
|           |     N     |           |           |           |     road  |
|           | avigation |           |    stolen | traveling |           |
|           |           |           |           |           |  services |
|           |           |           |  vehicles |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **A       | -         | -         | -         | -         | -         |
| VIATION** | Precision |   Precise |    Local, |    Closer |   Airport |
|           |     and   |           |           |           |           |
|           |     non-  |  airfield |  national |  aircraft |   surface |
|           | precision |     and   |     and   |     s     |           |
|           |     al    |           |     inte  | eparation |   traffic |
|           | l-weather |   landing | rnational |           |     m     |
|           |     a     |     aid   |           | standards | anagement |
|           | pproaches |     to    |  en-route |     for   |           |
|           |           |     all   |     n     |     more  | -   Less  |
|           |    (WAAS) |           | avigation |           |     expen |
|           |           | airports, |           | efficient | sive/more |
|           | -   M     |     r     | -   Wind  |     air   |           |
|           | onitoring | egardless |     shear |           |  accurate |
|           |     of    |     of    |           |   traffic |           |
|           |     wing  |     de    | detection |     m     |  avionics |
|           |     d     | velopment |           | anagement |           |
|           | eflection |           | -         |           | -         |
|           |     in    | -         |    Search | -         |  Enhanced |
|           |           |    Direct |     and   |  Seamless |     Loran |
|           |    flight |           |           |           |     C     |
|           |           |   routing |  location |  (global) |           |
|           | -         |     for   |     of    |     air   | in-flight |
|           | In-flight |           |           |     space |     n     |
|           |     m     |  aircraft |    downed |     m     | avigation |
|           | onitoring |     fuel  |           | anagement |           |
|           |     of    |           |  aircraft |           |           |
|           |           |   savings |           |           |           |
|           |  position |           |           |           |           |
|           | /location | -   LAAS  |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| *         | -   N     | -         | -   All   | -         | -         |
| *MARITIME | avigation |    Search |           |    Vessel |  Dredging |
| AND       |     on    |     and   |   weather |           |     of    |
| WA        |     the   |           |           |   traffic |           |
| TERWAYS** |     high  |    rescue |    harbor |           |   harbors |
|           |     seas  |           |     n     |  services |     and   |
|           |           | -         | avigation |           |           |
|           | -   Po    |  Location |           | -         | waterways |
|           | sitioning |     of    |  approach |  Enhanced |           |
|           |     of    |     c     |           |     Loran | -         |
|           |     buoys | ommercial | -         |     C     |  Offshore |
|           |     and   |           |    Harbor |           |           |
|           |           |   fishing |           |    marine |  drilling |
|           |  nav-aids |     traps |  facility |     n     |           |
|           |           |     and   |     m     | avigation |  research |
|           | -   M     |     nets  | anagement |           |           |
|           | onitoring |           |           | -         | -         |
|           |     de    | -   M     | -         | Observing |   Oceanic |
|           | flections | onitoring | Precision |     tides |           |
|           |     in    |           |     ice   |     and   |  research |
|           |     dams  |  icebergs |           |           |           |
|           |           |     and   |  breaking |  currents |           |
|           |           |     rouge |     o     |           |           |
|           |           |     flows | perations |           |           |
|           |           |           |           |           |           |
|           |           | -         |           |           |           |
|           |           |   Coastal |           |           |           |
|           |           |     N     |           |           |           |
|           |           | avigation |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **COMMUNI | -         | -         | -         | -         | -   S     |
| CATIONS** |   Precise | Wide-area |    Mobile |   Tagging | tochastic |
|           |           |           |     use   |     of    |     n     |
|           |    timing |    synchr |           |     in    | etworking |
|           |     for   | onization |  position | formation |     among |
|           |     in    |     of    |     dete  |     for   |     co    |
|           | terfacing |     h     | rmination |     tim   | operative |
|           |           | igh-speed |     for   | e-delayed |           |
|           |  messages |           |     paid  |           |    mobile |
|           |           |  networks |           |  transfer |           |
|           | -   V     |           |   linking |     to    | platforms |
|           | alidation | -         |     to    |     data  |           |
|           |     of    |    Differ |     PCS   |     ports | -         |
|           |     in    | entiation |           |           | US/Global |
|           | formation |     of    | -         | -         |     In    |
|           |     tra   |           |  National |  Personal | formation |
|           | nsmission |  wireless |           |     n     |     Infra |
|           |           |     mode: |   Spatial | avigation | structure |
|           | -         |           |     Data  |     and   |           |
|           |   Network | cordless, |     Infra |           |           |
|           |     m     |           | structure | reporting |           |
|           | anagement | cellular, |           |           |           |
|           |     and   |     s     |           |           |           |
|           |           | atellite, |           |           |           |
|           |   control |     etc.  |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **ENVI    | -         | -         | -         | -         | -         |
| RONMENTAL |    Ground | Hazardous |   Mapping |    Sudden |   Precise |
| PRO       |           |     waste |     of    |     alert |           |
| TECTION** |   mapping |     site  |     su    |     for   |  location |
|           |     of    |     inve  | b-surface |           |     of    |
|           |     e     | stigation |     cont  |    stored |           |
|           | cosystems |           | amination |           |    stored |
|           |           | -   M     |           | hazardous |           |
|           | -   Oil   | onitoring | -         |           | hazardous |
|           |     spill |     of    |  Tracking | materials |           |
|           |           |           |     of    |     moved | materials |
|           |  tracking |   natural |           |           |           |
|           |     and   |     gas   | migratory |   without | -         |
|           |           |           |           |           |   Precise |
|           |  clean-up | pipelines |   animals |   consent |           |
|           |           |           |           |           |  location |
|           | -         | -         | -   B     | -         |     of    |
|           |   Mapping |    Ground | oundaries |   Precise |           |
|           |     of    |     water |     of    |     n     |  sampling |
|           |     con   |     level |           | avigation |           |
|           | taminated |           | catchment |     to    |    points |
|           |           | elevation |           |           |           |
|           | sediments |           |   basins, |   sampled | -         |
|           |     in    | -         |           |           |  Location |
|           |           |  Criminal |    sludge |    points |     of    |
|           |   harbors |     inve  |           |           |     pest  |
|           |     &     | stigation |  lagoons, | -         | icide-con |
|           |           |     of    |           |  Location | taminated |
|           |    rivers |           |   tailing |     of    |     homes |
|           |           | illegally |     areas |           |           |
|           | -   Dis   |           |           |    sites, | -         |
|           | tribution |    buried |           |           |    Ground |
|           |     of    |           |           |    wells, |           |
|           |     e     | hazardous |           |           |   mapping |
|           | cosystems |     waste |           |   storage |     of    |
|           |     con   |           |           |           |           |
|           | taminants |           |           |    tanks, | wellhead, |
|           |           |           |           |           |     sou   |
|           |           |           |           |  outfalls | rce-water |
|           |           |           |           |           |     p     |
|           |           |           |           |           | rotection |
|           |           |           |           |           |     areas |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **MINING, | -   E     | -         | -         | -         | -   S     |
| EX        | lectronic |  Accurate | Precision |   Robotic | ubsidence |
| CAVATION, |           |           |           |           |     m     |
| AND       |   marking | stockpile |  location |    mining | onitoring |
| CONST     |     of    |           |     for   |     &     |     &     |
| RUCTION** |     g     |    record |           |     e     |     re    |
|           | eological |           |    mining | xcavation | clamation |
|           |           |   keeping |     e     |           |           |
|           |    events |           | xplosives |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **PUBLIC  | -   Bus   | -         | -   Train | -         | -         |
| TRANSPO   |     fleet |  Railroad |           |  Improved |  Personal |
| RTATION** |     on    |     fleet |   control |           |           |
|           | -the-road |     m     |     and   | operator/ |    safety |
|           |     m     | onitoring |           | passenger |           |
|           | anagement |           | collision |           |           |
|           |           |           |           |  security |           |
|           |           |           | avoidance |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **R       | -         | -         | -   R     | -         | -   W     |
| ECREATION |    Hiking | Measuring | elocating |   Setting | ilderness |
| AND       |     and   |     at    |           |     lines |           |
| SPORTS**  |           |           |  favorite |     on    |    search |
|           |  mountain |    sports |           |           |     and   |
|           |           |           |   fishing |    sports |           |
|           |  climbing |    events |     spots |           |    rescue |
|           |           |           |           |    fields |           |
|           | -   E     | -         |           |           |           |
|           | lectronic |   Finding |           |           |           |
|           |     c     |           |           |           |           |
|           | ompassing |  historic |           |           |           |
|           |     for   |           |           |           |           |
|           |     or    |   locales |           |           |           |
|           | ientation |     in    |           |           |           |
|           |           |     w     |           |           |           |
|           |           | ilderness |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| *         | -         | -   Id    | -         | -         | -         |
| *FORESTRY |    Forest | entifying |  Unmanned | Precision |   Precise |
| AND       |     area  |           |           |     crop  |           |
| AGRI      |     and   |   species | (robotic) |           |  plowing, |
| CULTURE** |           |           |     h     |   dusting |           |
|           |    timber |  habitats | arvesting |     by    |  planting |
|           |           |           |           |           |     and   |
|           | estimates | -   Water | -         |  aircraft |     fe    |
|           |           |           |  Wildlife |           | rtilizing |
|           | -   Fire  | resources |           | -         |           |
|           |     p     |           |  tracking |    Ground |           |
|           | erimeters |           |           |     su    |           |
|           |           |           |           | bsidence, |           |
|           |           |           |           |           |           |
|           |           |           |           |  erosion, |           |
|           |           |           |           |     &     |           |
|           |           |           |           |     sur   |           |
|           |           |           |           | veillance |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **GROUND  | -   In    | -         | -         | -         | -         |
| TRANSPO   | telligent |  Improved |   Vehicle |   Special |   Vehicle |
| RTATION** |     Trans |           |           |           |           |
|           | portation | emergency |  position |    travel |   control |
|           |           |           | /location |     in    |           |
|           |  System - |  services |     for   | formation |  systems: |
|           |     IVHS  |           |     n     |           |           |
|           |           | -         | avigation | -   Truck | position, |
|           | -         |  Accident |           |     fleet |           |
|           |   Highway |           |  tracking |     on    |  location |
|           |           |  location |     and   | -the-road |     and   |
|           |  facility |           |     m     |     m     |           |
|           |     and   |   studies | onitoring | anagement |  velocity |
|           |     ma    |           |           |           |           |
|           | intenance | -   M     | -         | -   St    | -   "You  |
|           |           | onitoring |   Highway | ereosonic |     are   |
|           | -   I     |           |     con   |     n     |     Here" |
|           | n-vehicle |    status | struction | avigation |           |
|           |           |     of    |           |     for   |   mapping |
|           |  wireless |           | -         |     the   |           |
|           |     voice |   bridges |  Guidance |     blind |  displays |
|           |           |           |     for   |           |           |
|           |   systems |           |           | -         |           |
|           |           |           |   robotic | Recording |           |
|           |           |           |           |     of    |           |
|           |           |           |   systems |     truck |           |
|           |           |           |           |           |           |
|           |           |           |           |    travel |           |
|           |           |           |           |           |           |
|           |           |           |           |    across |           |
|           |           |           |           |     state |           |
|           |           |           |           |     lines |           |
|           |           |           |           |     for   |           |
|           |           |           |           |           |           |
|           |           |           |           | automatic |           |
|           |           |           |           |     tax   |           |
|           |           |           |           |           |           |
|           |           |           |           |   billing |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| *         | -   Mea   | -   N     | -         | -   M     | -         |
| *SCIENCE, | surements | avigating |   Placing | onitoring | Measuring |
| T         |     of    |     of    |     s     |     ea    |           |
| ECHNOLOGY |     sea   |     space | atellites | rthquakes |    ground |
| AND       |     level |           |     into  |     and   |     s     |
| SPACE**   |     from  |  shuttles |     orbit |           | ubsidence |
|           |     s     |           |           |  tectonic |           |
|           | atellites | -         | -         |           | -         |
|           |           | Measuring |   Precise |    plates |   Precise |
|           | -         |     at    |           |           |           |
|           | Measuring | mospheric |    global | -   Users |    atomic |
|           |     river |     water |           |           |     l     |
|           |     flood |     vapor |   mapping |   weather | aboratory |
|           |           |     from  |     of    |           |           |
|           |    crests |     the   |     the   |   balloon |    timing |
|           |           |           |     i     |           |           |
|           | -   S     |    ground | onosphere |  position |           |
|           | pacecraft |           |           |     r     |           |
|           |           |           | -   At    | adiosonde |           |
|           |  attitude |           | mospheric |           |           |
|           |           |           |     te    | -         |           |
|           |   control |           | mperature |   Weather |           |
|           |           |           |           |     and   |           |
|           |           |           | profiling |           |           |
|           |           |           |           |   climate |           |
|           |           |           |           |           |           |
|           |           |           |           |  modeling |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **        | -   E     | -   Sing  | -   Hyd   | -         | -   Area  |
| SURVEYING | lectronic | le-handed | rographic |   Roadway |     me    |
| AND       |     bench |     high  |           |           | asurement |
| MAPPING** |           |           | surveying | profiling |           |
|           |   marking | precision |           |     with  |   without |
|           |     for   |           | -   Real  |           |     tria  |
|           |           |   surveys |     time  |   kinetic | ngulation |
|           |  absolute |           |     DPS   |     GPS   |           |
|           |           | -         |     with  |     in    | -         |
|           | latitude, | Measuring |           | tegration | Efficient |
|           |           |     and   |  regional |     with  |     and   |
|           | longitude |           |     point |     GIS   |           |
|           |     and   | recording |           |     for   |  accurate |
|           |           |     of    |   network |     more  |     photo |
|           |  altitude |           |           |           |           |
|           |           |  property | reference |  reliable |   surveys |
|           | -   Oil   |     b     |           |           |           |
|           |     and   | oundaries |  stations |   mapping | -         |
|           |           |           |           |     and   |  National |
|           |   mineral | -   De    | -   I     |     data  |           |
|           |     pr    | formation | ndustrial |     c     |   Spatial |
|           | ospecting |     en    |           | ollection |     Data  |
|           |           | gineering | surveying |           |     Infra |
|           |           |           |           |           | structure |
|           |           |   surveys | -         |           |           |
|           |           |           |  Robotics |           |           |
|           |           |           |     manu  |           |           |
|           |           |           | facturing |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| **HEALTH  | -         | -         | -         | -         | -   A     |
| CARE**    |  Tracking |    Epidem | Immediate |  Personal | nalytical |
|           |           | iological |           |     n     |           |
|           |   disease |           |  position | avigation |   medical |
|           |     s     |   mapping | /location |     for   |           |
|           | pread/dis |           |     of    |     blind |  modeling |
|           | tribution |           |           |           |           |
|           |           |           |   medical |   persons |           |
|           | -         |           |           |           |           |
|           |   Precise |           | personnel |           |           |
|           |           |           |     and   |           |           |
|           |    timing |           |     sp    |           |           |
|           |     in    |           | ecialists |           |           |
|           |           |           |           |           |           |
|           |   med-lab |           |           |           |           |
|           |     tests |           |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+

Source: US GPS Industry Council and user input

### Future PVT Operations Concept

To successfully implement military and civil operational concepts,
growing PVT needs in all operating environments - land, sea, subsurface,
air, and space - must be met. Users must be able to develop and execute
plans without PVT constraints. To provide the needed PVT capability, the
USG may rely on a variety of systems, including space-based,
terrestrial, and user specific, each with its own operations concept.

## PVT MISSION AREAS AND MISSION NEEDS

### PVT Mission Areas for DoD

This CRD supports the DoD mission areas identified in the latest listing
published by the Under Secretary of Defense for Acquisition and
Technology and shown in Table 1-3. The primary mission area for PVT,
"#357 Navigation and Position Fixing," is highlighted. Timing is not a
numbered mission area, but should be considered for addition.

Table 1-3: DoD Mission Areas Supported by PVT

  ----------- -------------------------- ----------- --------------------------
  **MISSION   **MISSION AREA TITLE**     **MISSION   **MISSION AREA TITLE**
  AREA**                                 AREA**      

  TBD         Precision Timing           307         Special Operations Forces

  110         Strategic Offense          340         Theater and Tactical
                                                     Programs

  210         Land Warfare               342         Surveillance and Warning

  214         Ground Based Anti-Air and  350         Navigation/Warfare C2
              Tactical Missile Defense               

  215         Land Warfare Support       351         Land Warfare C2

  220         Air Warfare                352         Air Warfare C2

  225         Air Warfare Support        353         Naval Warfare C2

  230         Naval Warfare              **357**     **Navigation and Position
                                                     Fixing\***

  261         Inter-Theater Airlift      370         Electronic Combat

  262         Inter-Theater Sealift      400         Defense-Wide Mission
                                                     Support

  263         Intra-Theater Airlift      410         Space Launch Orbital
                                                     Support

  300         Command, Control,          998         Counter-Narcotics
              Communications, and                    
              Intelligence Programs                  
  ----------- -------------------------- ----------- --------------------------

\* Primary mission area

### PVT Mission Areas for Other Federal Agencies.

GPS has become a "public utility" for many civil uses and a critical
component of the Global Information Infrastructure.

The DOT requires a PVT capability to assist civil aeronautical,
maritime, and terrestrial navigators, to improve safety and efficiency
while minimizing environmental impacts of the nation's transportation
infrastructure. Other Federal agencies require PVT capabilities for
geodesy, oceanography, meteorology, seismic monitoring, space
navigation, and geographic information systems development.

Mission Areas for Other Entities

State and local governments and many private industries also use PVT
services to improve productivity and introduce new services supporting
economic growth and international competitiveness.

Increasing private sector involvement has affected the evolution of the
FRP. The PVT system must ensure, in accordance with the national policy
found in OMB Circular A-76, that the private sector is considered in the
design, development, installation, operation, and maintenance of all
equipment and systems required to provide common-use radionavigation
aids in support of the FRP (within the constraints of national
security).

### Mission Needs

1.6.4.1 [Related Activities]{.underline}. The DoD and other agencies
have several ongoing PVT-related initiatives and programs. For the Air
Force, the major initiative is the Global Access, Navigation, and Safety
(GANS) effort. Figure 1-3 illustrates some of the interrelationships
between Air Force programs that fall under the GANS umbrella and those
that relate to PVT systems. Some of the programs, initiatives, and
recommendations are interrelated, while others are not. Some of the
initiativess, such as protection and prevention and GPS 2000, involve
other eervices or DoD agencies, so do not entirely fall under GANS.

As Figure 1-3 further illustrates, there are major initiatives outside
the DoD that will also affect future PVT requirements and programs. The
widespread----nd rapidly growing--- civil use of GPS will certainly
drive new requirements. New international civil air rules, leading to
"free flight" will also impact PVT requirements worldwide. The Report of
the White House Commission on Aviation Safety and Security (Gore Report)
will also impact PVT systems (see paragraph 1.1.3). All PVT related
Similar and associated acquisitions should be closely coordinated by DoD
and DOT to avoid duplication of effort.

The Worldwide Navigation ORD will contain the subset of military,
commercial, and civil PVT requirements to be fulfilled specifically by
the GPS . he Protection and Prevention ORD will include military
requirements for ground or air-based protection and prevention systems,
plus identify any NAVWAR-unique requiremen to incorporatinge GPS
capabilities in military platforms will be included in each system's
Oent. Finally the GANS CRD will contain the complete set of GANS
requirements, including stand-alone systems, as well as space system
requirements contained in the GPS ORD.

![](media/image4.emf){width="4.959027777777778in"
height="3.7819444444444446in"}

Figure 1-3. Relationship of Position, Velocity & Timing System
Requirements and Various Safety and Navigation Programs

1.6.4.2 [Related]{.underline} [Requirements Requirements Documents and
Plans]{.underline}. The MNSs, CRDs, ORDs and plans listed below are the
primary sources of PVT shortcomings stated in Section 3 and requirements
stated in Section 4is CRD to mission ted below. requirements have been
identified in the CRD process by requirements solicitation and
collection by AFSPC and DOT. In each case, tified that are reflected in
the CR

1.6.4.2.1 [Air Force Space Command MNS 003-92 for an Improved Worldwide
Navigational Positioning System]{.underline}, 28 Apr 1993. This MNS
identifies a need for continued global navigation and improved accuracy
and timing. According to the MNS, existing systems do not meet all DoD
requirements as established in the FRP and the CJCS MNP.

1.6.4.2.2 [Air Combat Command MNS 003-95 for Operational Protection and
Prevention of Global Space-based Navigation Systems]{.underline}, 27 Sep
1995. This MNS identifies a mission-based need to protect the ability of
US military forces to use the GPS, to prevent adversaries from using the
GPS, and to allow the civil community access to the GPS outside a
specified area of responsibility.

1.6.4.2.3 [AFSPC]{.underline} [Space Information Dominance Mission Area
Plan]{.underline}, 17 Dec 1996. This mission area plan consolidates
long-range planning for five space-related mission areas. The mission
need analysis documented by the plan identifies deficiencies in the
navigation mission area. Deficiencies were noted in availability,
integrity, accuracy, security (ability to protect a military advantage
in navigation systems), control segment robustness, and integration of
GPS navigation capability into military weapon systems.

4.  [Army Signal Center]{.underline} [XXD for the]{.underline} [GPS
    Tactical Receiver]{.underline}, 24 March 97. This ORD documents the
    Army's need for GPS receivers to replace obsolete equipment and to
    satisfy requirements created by digitization of the battlefield. It
    also represents a step toward implementing GPS 2000 within the Army.

1.6.4.2.5 [Air Mobility Command]{.underline} [CRD]{.underline} [001-97
for Global Air Traffic Management]{.underline}, Revision 1, 12 May 1997.
This CRD represents an initial military step to implement concepts known
as Communication, Navigation, Surveillance/Air Traffic Management
(CNS/ATM) in the civil aviation community. Since DoD operations
encompass the world, the term Global Air Traffic Management was chosen.
The CRD documents a need for an avionics suite of communications,
navigation, and surveillance equipment to enable "free flight" of
aircraft. Free flight is the ability of aircraft to choose own routes,
speeds, and altitude in real time.

6.  [Air Force Flight Standards Agency]{.underline} [ORD]{.underline} [I
    for Joint Precision Approach Landing System (JPALS)]{.underline}, 15
    Oct 1996. This ORD followed the Joint MNS for Precision Approach and
    Landing Capability, validated by the JROC on 29 Aug 95. It states
    detailed requirements for a next generation precision approach and
    landing system. The capability described will provide joint
    operational capability for US forces to perform assigned
    conventional and special operations from fixed base, shipboard,
    tactical, and austere environments under a wide range of
    meteorological conditions.

```{=html}
<!-- -->
```
7.  [Air Mobility Command MNS for Required Navigation
    Performance]{.underline} [(Draft)]{.underline}, Undated. This MNS is
    being generated to enable Air Mobility Command to operate its
    aircraft in airspace where required navigation performance (RNP)
    standards will apply.

```{=html}
<!-- -->
```
8.  [CJCS Master Navigation Plan]{.underline}, 20 May 1994. See Section
    1.4.3 above.

1.6.4.2.9 [1994]{.underline} [Federal Radionavigation Plan]{.underline},
May 1995. See Section 1.4.2.3 above.

## REQUIREMENTS ALLOCATION

This CRD describes many requirements that most likely cannot be met by a
single system. Multiple ORDs are anticipated to be developed from this
CRD to allocate these requirements to specific systems for development
and procurement. While the user and acquisition communities will
determine architectures and allocate requirements to specific ORDs, the
allocation of those requirements to specific ORDs is beyond the scope of
the CRD. In order to ensure all requirements are satisfied, the AMP
should contain a mechanism to section thattrace rerom the CRD to
specific ORDs.

## DESCRIPTION OF REQUIRED CHARACTERISTICS

Future PVT system-of-systems will support the mission areas by providing
the requisite position accuracy, velocity accuracy, timing accuracy,
integrity, availability, coverage, supportability, security,
survivability, interoperability, and affordability. The system will also
support civil and commercial users by providing continuity of service.
These Required System Characteristics for PVT systems and their
descriptions are outlined in Table 1-4. Specific requirements for each
Required System Characteristic may be found in Section 4 with a tabular
summary of requirements in Appendix A.

Table 1-4: Required System Characteristics

+----------------+-----------------------------------------------------+
| **CH           | **DESCRIPTION**                                     |
| ARACTERISTIC** |                                                     |
+----------------+-----------------------------------------------------+
| Position       | -   Degree of conformance of an estimated position  |
| Accuracy       |     at a given time with the true position at that  |
|                |     time                                            |
|                |                                                     |
|                | -   Includes a statement of the uncertainty in      |
|                |     position                                        |
|                |                                                     |
|                | -   Three types of accuracy:                        |
|                |                                                     |
|                | -   Predictable - accuracy of a system's position   |
|                |     solution with respect to the charted solution.  |
|                |                                                     |
|                | -   Repeatable - Accuracy with which a user can     |
|                |     return to a position whose coordinates have     |
|                |     been measured at a previous time with the same  |
|                |     navigation system                               |
|                |                                                     |
|                | -   Relative - Accuracy with which a user can       |
|                |     measure position relative to that of another    |
|                |     user of the same navigation system at the same  |
|                |     time                                            |
+----------------+-----------------------------------------------------+
| -   Velocity   | -   Degree of conformance between the estimated or  |
|     Accuracy   |     measured velocity of a platform at a given time |
|                |     and its true velocity.                          |
+----------------+-----------------------------------------------------+
| -   Timing     | -   Degree of conformance of an estimated time or   |
|     Accuracy   |     time interval with the true time; for           |
|                |     standard-based timing                           |
|                |                                                     |
|                | -   Ability of the system to provide accurate       |
|                |     common time reference relative to UTC (USNO).   |
|                |                                                     |
|                | -   Precise measurements for accurate time transfer |
|                |     to fixed station and mobile users (air, land,   |
|                |     sea, and space).                                |
|                |                                                     |
|                | -   Precise measurements for supporting frequency   |
|                |     calibration and rating of local clocks for      |
|                |     self-contained operation in the absence of time |
|                |     transfer information or signals                 |
|                |                                                     |
|                | -   Ability of the system to provide standardized   |
|                |     timing information interfaced to related or     |
|                |     integrated systems for extra-system             |
|                |     synchronization to a common reference           |
+----------------+-----------------------------------------------------+
| -   Integrity  | -   Ability of a system to provide timely warnings  |
|                |     to users when the system should not be used     |
|                |                                                     |
|                | -   Interpret signal information and determine if   |
|                |     the signal information exceeds the specified    |
|                |     performance criteria for that particular phase  |
|                |     of operation and provide timely warning         |
|                |                                                     |
|                | -   Navigation Signal Monitoring Capability -       |
|                |     monitor PVT signals from the system             |
|                |                                                     |
|                | -   Warning to Users - timely warning to users when |
|                |     specific satellites and/or the system is not    |
|                |     available for use                               |
|                |                                                     |
|                | -   Monitor system signal to ensure that the number |
|                |     and duration of unannounced/unwarned failures   |
|                |     which result in hazardously misleading          |
|                |     information (HMI) are minimized                 |
+----------------+-----------------------------------------------------+
| -              | -   Percentage of time that the services of the     |
|   Availability |     system are adequate to permit all requirements  |
|                |     to be met including determination of position,  |
|                |     velocity, or time to a specified level of       |
|                |     accuracy                                        |
|                |                                                     |
|                | -   Indication of the ability of the system to      |
|                |     provide usable service within the specified     |
|                |     coverage area                                   |
|                |                                                     |
|                | -   Signal availability is the percentage of time   |
|                |     that PVT signals transmitted from external      |
|                |     sources are available for use.                  |
|                |                                                     |
|                | -   Function of both the physical characteristics   |
|                |     of the environment and technical capabilities   |
|                |     of the transmitter facilities.                  |
+----------------+-----------------------------------------------------+
| -   Security   | -   Resistance to countermeasures including:        |
|                |     Meaconing, Interference, Jamming, and Intrusion |
|                |     (MIJI), physical attack, and sabotage           |
+----------------+-----------------------------------------------------+
| -   Continuity | -   Ability of a PVT system to provide required     |
|     of Service |     service over a specified period of time without |
|                |     interruption.                                   |
|                |                                                     |
|                | -   Expressed in terms of the probability of not    |
|                |     losing the radiated signals.                    |
|                |                                                     |
|                | -                                                   |
|                |                                                     |
|                | -                                                   |
+----------------+-----------------------------------------------------+
| Affordability  | -   Ability to meet requirements within defined     |
|                |     budgetary constraints.                          |
+----------------+-----------------------------------------------------+
| -   Coverage   | -   Surface area or space volume in which the       |
|                |     signals are adequate to permit all requirements |
|                |     to be met including determination of position,  |
|                |     velocity, or time to a specified level of       |
|                |     accuracy                                        |
|                |                                                     |
|                | -   Influenced by system geometry, signal power     |
|                |     levels, receiver sensitivity, atmospheric noise |
|                |     conditions, and other factors which affect      |
|                |     signal availability                             |
+----------------+-----------------------------------------------------+
| -              | -   Degree to which all logistics elements combine  |
| Supportability |     to satisfy system dependability requirements    |
|                |                                                     |
|                | -   Ability to maintain control of the system       |
|                |                                                     |
|                | -   Includes manufacture, delivery, integrated      |
|                |     training and simulation systems                 |
+----------------+-----------------------------------------------------+
| -              | -   Capability to avoid or withstand the impact of  |
|  Survivability |     a hostile environment (man-made or natural)     |
|                |     without suffering an abortive impairment of the |
|                |     ability to accomplish the most critical mission |
|                |     requirements                                    |
+----------------+-----------------------------------------------------+
| In             | -   Ability of PVT information to be readily used   |
| teroperability |     by numerous applications with applicable        |
|                |     formats                                         |
+----------------+-----------------------------------------------------+

**SECTION 2**

# RESERVED 

#   {#section .unnumbered}

# 

**SECTION 3**

# SHORTCOMINGS OF EXISTING SYSTEMS

## INTRODUCTION

This section addresses shortcomings in existing PVT systems and the
impact on future needs. While current systems satisfy most of today's
requirements, the increasingly stringent accuracy needs of users are
driving the demand for more capable PVT systems. The "Information Age"
has brought about the need for an unprecedented level of precision for
military, civil, and commercial PVT applications. Current and projected
systems cannot provide the position, velocity, and timing accuracy, nor
the integrity, availability, security, continuity of service, coverage,
supportability, survivability, or interoperability needed to support
tomorrow's dynamic operations. Additionally, in an environment of
constrained military budgets and manpower levels, new PVT systems must
be economically feasible and effective. These shortcomings directly lead
to the requirements presented in Section 4.

## EXISTING AND PROJECTED SYSTEMS DESCRIPTION

Table 3-1 provides a summary of the characteristics of the current and
projected major US military and civil PVT systems. A short description
of each system is provided in the following paragraphs. Other current
and projected PVT systems are addressed in Appendix E.

### Ground Controlled Approach/Precision Approach Radar

Ground Controlled Approach (GCA) and Precision Approach Radar (PAR) are
precision landing aids for military aircraft. A ground controller is
provided with aircraft position relative to a fixed approach path. The
operator announces aircraft location relative to the glideslope until
the pilot has visual contact with the runway or until a minimum altitude
is reached. No special equipment is needed on the aircraft itself. Voice
instructions are passed by very high frequency (VHF) and ultra-high
frequency radios. GCA and PAR are NATO standard precision landing
systems and are deployable.

Table 3-1. Current and Projected Major PVT Systems Summary

+------------+-------+-------+-------+-------+-------+-------+-------+
|            |       |       |       |       | **Sta |       |       |
|            |       |       |       |       | tus** |       |       |
+============+=======+=======+=======+=======+=======+=======+=======+
| **System** | *     | **    | **    | *     | **    | **Ci  | **    |
|            | *Serv | Cover | Accur | *Avai | DoD** | vil** | Opera |
|            | ice** | age** | acy** | labil |       |       | tor** |
|            |       |       |       | ity** |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Ground     | Pos   | 18.5  | ±     |       | O     |       | Mil   |
| Controlled | ition | km    | 1.3°  |       | perat |       | itary |
| Approach/  |       | from  | az    |       | ional |       | Ser   |
| Precision  |       | r     | imuth |       |       |       | vices |
| Approach   |       | unway |       |       |       |       |       |
| Radar      |       | thre  | ±     |       |       |       |       |
|            |       | shold | 1.1°  |       |       |       |       |
|            |       | (dep  | elev  |       |       |       |       |
|            |       | loyed | ation |       |       |       |       |
|            |       | world |       |       |       |       |       |
|            |       | wide) | ± 60  |       |       |       |       |
|            |       |       | m     |       |       |       |       |
|            |       |       | range |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Global     | Posi  | G     | Horz  | 9     | O     | Ra    | US    |
| P          | tion, | lobal | (SEP) | 9.85% | perat | pidly | Air   |
| ositioning | Velo  | and   |       | (24   | ional | incre | Force |
| System     | city, | parts | SPS:  | hour  |       | asing |       |
|            | T     | of    | 100 m | inte  |       | use,  |       |
|            | iming | Space |       | rval) |       | repl  |       |
|            |       |       | PPS:  |       |       | acing |       |
|            |       |       | 16 m  |       |       | most  |       |
|            |       |       |       |       |       | sy    |       |
|            |       |       | Ti    |       |       | stems |       |
|            |       |       | ming: |       |       |       |       |
|            |       |       | 100   |       |       |       |       |
|            |       |       | nsec  |       |       |       |       |
|            |       |       |       |       |       |       |       |
|            |       |       | Velo  |       |       |       |       |
|            |       |       | city: |       |       |       |       |
|            |       |       | .2    |       |       |       |       |
|            |       |       | m/sec |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Instrument | Pos   | Local | In    | ≅ 99% | O     | Trans | Mil   |
| Landing    | ition | izer: | m     |       | perat | ition | itary |
| System     |       | ± 2°  | eters |       | ional | to    | Serv  |
|            |       | from  | (2δ)  |       |       | WAAS  | ices, |
|            |       | c     |       |       |       | and   | FAA   |
|            |       | enter | Cat   |       |       | LAAS  |       |
|            |       | line, | III:  |       |       | (2005 |       |
|            |       | G     |       |       |       | to    |       |
|            |       | lides | ± 4.1 |       |       | 2010) |       |
|            |       | lope: | az    |       |       |       |       |
|            |       | 3°    | imuth |       |       |       |       |
|            |       | from  |       |       |       |       |       |
|            |       | h     | ± 0.4 |       |       |       |       |
|            |       | orizo | elev  |       |       |       |       |
|            |       | ntal, | ation |       |       |       |       |
|            |       | M     |       |       |       |       |       |
|            |       | arker |       |       |       |       |       |
|            |       | Be    |       |       |       |       |       |
|            |       | acon: |       |       |       |       |       |
|            |       |       |       |       |       |       |       |
|            |       | ± 40° |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Inertial   | Posi  | U     | Airc  |       | O     | O     | Mil   |
| Navigation | tion, | nlimi | raft: |       | perat | perat | itary |
| Systems    | Vel   | ted - |       |       | ional | ional | and   |
| (many      | ocity | used  | Pos:  |       |       |       | Civil |
| v          |       | on    | ±     |       |       |       | using |
| ariations) |       | airc  | 1.85  |       |       |       | plat  |
|            |       | raft, | km/hr |       |       |       | forms |
|            |       | s     |       |       |       |       |       |
|            |       | hips, | Vel:  |       |       |       |       |
|            |       | s     | ±     |       |       |       |       |
|            |       | ubmar | 0.76  |       |       |       |       |
|            |       | ines, | m/sec |       |       |       |       |
|            |       | space |       |       |       |       |       |
|            |       | craft |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Long-Range | Posi  | C     | Pr    | \>    | P     | Pha   | US    |
| Navigation | tion, | ONUS, | edict | 99%   | hased | seout | Coast |
| (LORAN-C)  | T     | US    | able: |       | out   | by    | Guard |
|            | iming | co    | 460   |       | in    | Dec   |       |
|            |       | asts, | m,    |       | 1994  | 2000, |       |
|            |       | Great | R     |       |       | trans |       |
|            |       | L     | epeat |       |       | ition |       |
|            |       | akes, | able: |       |       | to    |       |
|            |       | A     | 18 to |       |       | GPS   |       |
|            |       | laska | 90 m  |       |       |       |       |
|            |       |       |       |       |       |       |       |
|            |       |       | Ti    |       |       |       |       |
|            |       |       | ming: |       |       |       |       |
|            |       |       | 200   |       |       |       |       |
|            |       |       | nsec  |       |       |       |       |
|            |       |       | (no   |       |       |       |       |
|            |       |       | rmal) |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Microwave  | Pos   | 40    | Cat I | Near  |       | Depl  | FAA   |
| Landing    | ition | de    |       | 100%  |       | oying |       |
| System     |       | grees | ± 9.1 |       |       | 29    |       |
|            |       | from  | m az  |       |       | sets; |       |
|            |       | c     |       |       |       | trans |       |
|            |       | enter | ± 3.0 |       |       | ition |       |
|            |       | line  | m el  |       |       | to    |       |
|            |       | out   |       |       |       | WAAS  |       |
|            |       | to 20 |       |       |       | and   |       |
|            |       | nm in |       |       |       | LAAS  |       |
|            |       | both  |       |       |       | (2005 |       |
|            |       | direc |       |       |       | to    |       |
|            |       | tions |       |       |       | 2010) |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Ra         | Pos   | CONUS | Aer   | \>    | Ope   | \>    | Mil   |
| diobeacons | ition |       | onaut | 99%   | ratio | 700   | itary |
| (Ae        |       |       | ical: |       | nal - | FAA   | Serv  |
| ronautical |       |       | ± 3°  |       | about | aer   | ices, |
| &          |       |       | to ±  |       | 200   | onaut | FAA,  |
| Maritime)  |       |       | 10°   |       | ae    | ical, | US    |
|            |       |       |       |       | ronau | Pha   | Coast |
|            |       |       | Mari  |       | tical | seout | G     |
|            |       |       | time: |       |       | by    | uard, |
|            |       |       | ± 3°  |       |       | 2000  | about |
|            |       |       |       |       |       | at    | 800   |
|            |       |       |       |       |       | VOR   | n     |
|            |       |       |       |       |       | s     | on-Fe |
|            |       |       |       |       |       | ites, | deral |
|            |       |       |       |       |       | 4     |       |
|            |       |       |       |       |       | USCG  |       |
|            |       |       |       |       |       | mar   |       |
|            |       |       |       |       |       | itime |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Omega      | Posi  | Worl  | Pr    | \>    |       | Term  | S     |
|            | tion, | dwide | edict | 99%   |       | inate | ystem |
|            | T     | conti | able/ |       |       | US    | co    |
|            | iming | nuous | R     |       |       | par   | ntrol |
|            |       |       | epeat |       |       | ticip | and   |
|            |       |       | able: |       |       | ation | US    |
|            |       |       |       |       |       | Sep   | sta   |
|            |       |       | 3.7   |       |       | 1997  | tions |
|            |       |       | to    |       |       |       | by US |
|            |       |       | 7.4   |       |       |       | Coast |
|            |       |       | km    |       |       |       | G     |
|            |       |       |       |       |       |       | uard, |
|            |       |       | Rela  |       |       |       | ove   |
|            |       |       | tive: |       |       |       | rseas |
|            |       |       |       |       |       |       | sta   |
|            |       |       | 463   |       |       |       | tions |
|            |       |       | to    |       |       |       | by    |
|            |       |       | 926 m |       |       |       | pa    |
|            |       |       |       |       |       |       | rtner |
|            |       |       |       |       |       |       | na    |
|            |       |       |       |       |       |       | tions |
+------------+-------+-------+-------+-------+-------+-------+-------+
| VHF        | Pos   | Line  | VOR - | Near  |       | VOR - | FAA   |
| Omnid      | ition | of    | ±     | 100%  |       | begin |       |
| irectional |       | s     | 4.5°  |       |       | pha   |       |
| Rang       |       | ight, |       |       |       | seout |       |
| e/Distance |       | w     | DME - |       |       | 2005  |       |
| Measuring  |       | idely | 0.5   |       |       |       |       |
| Equipment  |       | dep   | nm    |       |       | DME - |       |
|            |       | loyed |       |       |       | pha   |       |
|            |       |       |       |       |       | seout |       |
|            |       |       |       |       |       | 2000  |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Tactical   | Pos   | Line  | Azi   | \>    | Ope   | 640   | Mil   |
| Air        | ition | of    | muth: | 99%   | ratio | be    | itary |
| Navigation |       | s     | ± 1°  |       | nal - | acons | Serv  |
|            |       | ight, | (135  |       | 173   | ope   | ices, |
|            |       | w     | Hz    |       | bea   | rated | FAA   |
|            |       | idely | ele   |       | cons; | for   |       |
|            |       | dep   | ment, |       | begin | DoD   |       |
|            |       | loyed | ± 4°  |       | pha   |       |       |
|            |       |       | (15   |       | seout |       |       |
|            |       |       | Hz    |       | 2005  |       |       |
|            |       |       | ele   |       |       |       |       |
|            |       |       | ment) |       |       |       |       |
|            |       |       |       |       |       |       |       |
|            |       |       | Dist  |       |       |       |       |
|            |       |       | ance: |       |       |       |       |
|            |       |       | same  |       |       |       |       |
|            |       |       | as    |       |       |       |       |
|            |       |       | DME   |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| GPS Wide   | Posi  | 48    | Enr   | Enr   |       | IOC:  | FAA   |
| Area       | tion, | conti | oute: | oute: |       | end   |       |
| Au         | Velo  | guous | 100 m | 99    |       | 1998  |       |
| gmentation | city, | st    | (     | .999% |       |       |       |
| System     | T     | ates, | 95%); |       |       | FOC:  |       |
|            | iming | Ha    | Cat   | Cat   |       | by    |       |
|            |       | waii, | I: 12 | I:    |       | 2001  |       |
|            |       | P     | m     | 99.9% |       |       |       |
|            |       | uerto | vert  |       |       |       |       |
|            |       | Rico, | ical, |       |       |       |       |
|            |       | part  | 40 m  |       |       |       |       |
|            |       | of    | horiz |       |       |       |       |
|            |       | A     | ontal |       |       |       |       |
|            |       | laska | (95%) |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| GPS Local  | Posi  | Exp   | TBD - | TBD   |       | Spec  | FAA   |
| Area       | tion, | ected | must  |       |       | ifica |       |
| Au         | Velo  | to be | meet  |       |       | tions |       |
| gmentation | city, | si    | Cat   |       |       | by    |       |
| System     | T     | milar | I     |       |       | 1998, |       |
|            | iming | to    | I/III |       |       | Cat   |       |
|            |       | WAAS  | prec  |       |       | I     |       |
|            |       |       | ision |       |       | I/III |       |
|            |       |       | app   |       |       | capab |       |
|            |       |       | roach |       |       | ility |       |
|            |       |       |       |       |       | by    |       |
|            |       |       |       |       |       | 2005  |       |
+------------+-------+-------+-------+-------+-------+-------+-------+

### Global Positioning System

The GPS is a space-based radionavigation capability. Due to superior
coverage, accuracy, availability, and survivability, it is rapidly
supplanting many systems. Originally developed as a force enhancement
capability for US forces, a role that will continue for the foreseeable
future, GPS is proving to be of significant benefit to the civil
community in an increasingly large number and variety of applications.
To make the service generally available while ensuring that national
security interests are protected, two services are provided. Precise
positioning service provides full system accuracy to US and allied
forces and other authorized users. Standard positioning service provides
accurate positioning capability to civil users worldwide. Several
upgrades are underway or planned for the space (Block IIR and IIF) and
operational control segments and a wide variety of UE is currently
available.

### Instrument Landing System

The Instrument Landing System (ILS) provides military and civil aircraft
with precision vertical and lateral navigation (guidance) information
during approach and landing. Associated marker beacons or distance
measuring equipment identify the final approach fix, the point where the
final descent to the runway is initiated. Federal regulations require
that part 121 aircraft be equipped with ILS avionics and it is also
extensively used by general aviation. ILS is a standard civil landing
system in the US and abroad and is protected by ICAO agreement to 1 Jan
2010.

### Inertial Navigation Systems

Inertial Navigation Systems (INS) are self-contained systems that
operate autonomously and provide reliable and accurate platform
attitude, position, and velocity information regardless of weather or
electronic warfare. They are capable of worldwide operation over a wide
range of velocities, attitudes, and accelerations. After initialization
using known position and velocity, an inertial system provides
continuous estimates of position, velocity, and attitude. Key components
of an INS are an inertial measurement unit, a navigation computer, and a
control and display unit. Major military INS programs include the USAF
Standard Navigator, Navy Carrier Aircraft INS, Aircraft Carrier
Navigation Systems, Electrically Suspended Gyroscope Navigation, and the
AN/WSN-5 Inertial Navigation System.

### Long Range Navigation 

The Long-Range Navigation (LORAN-C) system provides radionavigation
coverage for maritime operations in US coastal areas. It provides
position and precise timing services for military and civil air, land,
and marine users. It is approved as a supplemental air navigation system
and serves users that operate under visual flight rules. The system
serves the 48 contiguous states, their coastal areas, the Great Lakes,
and parts of Alaska. LORAN-C is expected to continue service until
December 2000 to accommodate transition to GPS. Operations after that
will depend on whether LORAN-C meets requirements that can't be
satisfied by GPS or other systems. The DoD requirement for LORAN-C ended
in 1994.

### Microwave Landing System

The Microwave Landing System (MLS) does not have the siting problems of
ILS and offers higher accuracy and greater flexibility, permitting
precision landings at more airports. A limited procurement of Category I
MLS equipment began in 1992 for installation at 29 sites. The FAA
terminated the development of Category II and III MLS based on favorable
GPS test results and budgetary restraints. Category II and III equipment
could be purchased on the open market if a need should arise in the
future. Phaseout of Category I MLS is expected to begin in 2005 and be
completed by 2010. The USAF developed and is deploying 37 mobile MLS
systems for contingency operations.

### Radiobeacons

Aeronautical radiobeacons are used for transition from enroute to
precision terminal approach facilities and as nonprecision approach aids
at many airports. Some state and locally owned beacons are used to
provide weather information to pilots. In Alaska and some remote areas,
radiobeacons are also used as enroute facilities. FAA operates more than
800 beacons, the military about 200, and non-Federally operated about
800. Where equivalent VHF Omnidirectional Range facilities are
available, decommissioning of FAA beacons will begin in 2000. Remaining
FAA stand-alone beacons will be rapidly phased out after 2005. Maritime
radiobeacons serve as backup to more sophisticated navigation systems
and as a low-cost, medium accuracy system for vessels equipped with only
minimal radionavigation equipment. Use has dwindled because of the
availability of inexpensive LORAN-C and GPS receivers. However, the US
Coast Guard (USCG) still operates four maritime beacons. Maritime
beacons not modified to carry differential GPS correction signals are
expected to be phased out by 2000.

### Omega

Omega was developed and implemented by the US Navy and system control
exercised by the Coast Guard. Eight stations are operated by the US and
six partner nations. International civil use includes the sole means of
oceanic aircraft navigation because of its worldwide coverage. Omega
also provides timing service. With the achievement of full operational
capability by GPS, it is anticipated that aviation users will quickly
transition to GPS. The US intends to terminate its role in Omega in
September 1997. The DoD no longer requires Omega, although limited use
is expected while the system remains operational.

### Very High Frequency Omnidirectional Range/Distance Measuring Equipment

Very High Frequency Omni-Range/Distance Measuring Equipment (VOR/DME) is
currently the primary means of navigation in the National Airspace
System (NAS). It will remain primary for enroute through non-precision
approach phases of flight until GPS is proven to meet appropriate RNP
levels and integrity requirements for these phases of flight and the GPS
WAAS is approved as a sole means of navigation. Phase out of VOR/DME
from the NAS is anticipated about 2005 with completion by 2010. DoD
requirements for VOR/DME will terminate when military aircraft are
properly integrated with appropriate GPS/augmentation user equipment and
GPS is certified by DoD to meet RNP for national and international
controlled airspace. The target date to begin phaseout of DME is 2000;
for VOR the date is 2005.

### Tactical Air Navigation

This is the military counterpart to VOR/DME. The DoD requirement for
Tactical Air Navigation (TACAN) will terminate when military aircraft
are properly integrated with appropriate GPS/augmentation user equipment
and GPS is certified by DoD to meet RNP for national and international
controlled airspace. Target date for beginning phase out of TACAN is
2005.

### GPS Wide Area Augmentation System

The WAAS is a GPS augmentation that provides a signal-in-space to
aviation users supporting enroute through Category I precision approach
navigation. WAAS provides: (1) integrity data on GPS and geostationary
earth orbit (GEO) satellites, (2) wide area differential corrections,
and (3) an additional ranging capability. A network of wide-area
reference stations and wide-area master stations receive and process GPS
satellite data to determine integrity, differential corrections,
residual errors, and ionospheric information for each monitored
satellite. This information is sent to a ground earth station and
uplinked, along with the GEO navigation message, to GEO satellites. GEO
satellites downlink this data on GPS Link 1 frequency. In addition to
GPS integrity, WAAS will verify its own integrity. Minimal modifications
to standard GPS receivers are required in order to use WAAS.

### GPS Local Area Augmentation System

The Local Area Augmentation System (LAAS) will provide corrections to
GPS (and WAAS) for aircraft within line of sight of a ground reference
station. It is expected to support Category II/III precision landing
applications. It will also provide information for Category I landings
at high capacity airports and certain locations where WAAS cannot
provide this service. Work in this area is being closely coordinated
with development of local and differential GPS systems for special
category I precision approaches being funded by private industry.
Funding and spectral placement of LAAS are issues that must be resolved,
but the FAA expects that LAAS Category II/III will be available for
public use by 2005.

## LIMITATIONS OF CURRENT SYSTEMS

The USG operates radionavigation systems as one of the necessary
elements to enable safe transportation and encourage commerce within the
United States. It is a goal of the USG to provide this service in a
cost-effective manner. In order to meet both civil and military
radionavigation needs, the Government has established a series of
radionavigation systems over a period of years. Each system utilizes the
latest technology available at the time of introduction to meet existing
or unfulfilled needs. Policies and plans for federally provided
radionavigation services are delineated in the FRP. The FRP describes
areas of authority and responsibility and provides a management
structure by which the individual USG operating agencies can define and
meet radionavigation requirements in a cost-effective manner. It is the
official source of radionavigation policy and planning for the USG. The
existence of privately operated radionavigation systems may also be a
factor in USG planning.

Current and projected PVT systems cannot meet future needs due to aging
equipment, much of which is labor and training intensive, and
anticipated higher accuracy needs. Current military systems do not meet
projected military requirements during conflicts in which an enemy may
attempt disrupt their usage. Also, providing extremely accurate PVT
signals to the general public, including foreign countries, could result
in adversaries using the service against the US.

While the survivability of any radionavigation system is
scenario-dependent, in almost any scenario the GPS is expected to be
more survivable than other systems because: (1) moving transmitters in
space are less vulnerable than ground-based transmitters; (2) spread
spectrum transmission techniques protect against jamming; (3)
anti-spoofing is available; and (4) transmitters are hardened against
EMP.

In addition to the major systems discussed above, there are numerous
other specialized PVT systems in use or projected. These systems are
addressed in Appendix E.

Current and projected major and other, mostly special purpose, PVT
systems and their capability to meet future requirements are depicted in
Table 3-2. For each system, a red (R), yellow (Y), or green (G)
indicator is used to portray the degree to which the PVT system is able
to meet future requirements for each required system characteristic.
Definitions of indicators and rationale for the indicators assigned to
each system are provided in Appendix F. Several foreign systems were
described in Section 1. While US military forces may use some of these
systems in non-hostile conditions, US Forces must not be dependent on
PVT assets of other nations. Only US PVT systems were rated and systems
with planned phaseout dates were not rated.

Table 3-2. Current and Projected PVT Systems' Capabilities to Meet
Future Requirements

<table style="width:100%;">
<colgroup>
<col style="width: 10%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 7%" />
</colgroup>
<thead>
<tr class="header">
<th></th>
<th colspan="12"><strong>REQUIRED</strong> <strong>SYSTEM
CHARACTERISTICS</strong></th>
</tr>
<tr class="odd">
<th><strong>MAJOR SYSTEMS</strong></th>
<th><strong>POSITIONACCY</strong></th>
<th><strong>VELOCITY ACCY</strong></th>
<th><strong>INTEGRITY</strong></th>
<th><p><strong>AVAILA-</strong></p>
<p><strong>BILITY</strong></p></th>
<th><strong>TIMING ACCY</strong></th>
<th><strong>COVER- AGE</strong></th>
<th><strong>SUPPOR-</strong> <strong>TABILITY</strong></th>
<th><p><strong>SECUR-</strong></p>
<p><strong>ITY</strong></p></th>
<th><strong>INTEROP/ STANDRD</strong></th>
<th><strong>CONTINU-ITY SVC</strong></th>
<th><strong>SURVIVA- BILITY</strong></th>
<th><strong>AFFORD-ABILITY</strong></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td>GCA/PAR</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
</tr>
<tr class="even">
<td>GPS</td>
<td>Y</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>Y</td>
</tr>
<tr class="odd">
<td>ILS</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
</tr>
<tr class="even">
<td>INS</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>R</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="odd">
<td>Maritime DGPS</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
</tr>
<tr class="even">
<td>GPS WAAS</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
</tr>
<tr class="odd">
<td>GPS LAAS</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
</tr>
<tr class="even">
<td><strong>OTHER SYSTEMS</strong></td>
<td colspan="12"></td>
</tr>
<tr class="odd">
<td>ATC Radar Beacon Sys</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
</tr>
<tr class="even">
<td>ATC Radar</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
</tr>
<tr class="odd">
<td>Bottom Contour Nav</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="even">
<td>Carrier Systems for Controlled Approach of Naval Aircraft</td>
<td>Y</td>
<td>R</td>
<td>G</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
</tr>
<tr class="odd">
<td>Celestial Nav</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>R</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="even">
<td>Differential GPS (military)</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
</tr>
<tr class="odd">
<td>Digital Airport Surveillance Radar</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="even">
<td>Direction Finding</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>G</td>
</tr>
<tr class="odd">
<td>Doppler</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="even">
<td>Digital Scene Matching Area Correlation</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="odd">
<td>Joint Tactical Information Dist System</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="even">
<td>Marine ATC &amp; Landing Systems</td>
<td>G</td>
<td>R</td>
<td>G</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
</tr>
<tr class="odd">
<td>Survey Instrument Az, Gyro (lt wt)</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="even">
<td>Stabilization Reference Package/Pos Det System</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>R</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="odd">
<td>Terrain Contour matching</td>
<td>G</td>
<td>G</td>
<td>G</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
<td>G</td>
<td>G</td>
</tr>
<tr class="even">
<td>Vessel Traffic Services</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>Y</td>
<td>R</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>Y</td>
<td>G</td>
<td>Y</td>
<td>G</td>
</tr>
</tbody>
</table>

## POSITION ACCURACY

### Shortcomings

3.4.1.1 [Timeliness]{.underline}. Current systems and methods will not
provide direct, real-time PVT information to the degree of accuracy
within the time constraints required to support all users of fielded or
emerging military systems.

3.4.1.2 [Civil Air Navigation]{.underline}. Current PVT systems and UE
cannot meet future civil air navigation accuracy requirements for the
approach and landing phase. Further, current systems cannot meet civil
marine or space navigation accuracy requirements.

3.4.1.3 [Seismic Surveys]{.underline}. To get one meter accuracy for the
positioning of shot holes and geophone locations, users must transport
extra equipment in order to set up a base station - GPS receiver, modem,
radios, extra batteries, solar panels.

3.4.1.4 [Geodetic Surveys]{.underline}. Users have no means of computing
geodetic quality positions in the field to check on results on the spot.

3.4.1.5 [Cable Mapping]{.underline}. To properly map fiber cable, it is
necessary to locate it properly with respect to lease boundaries,
railroad tracks, roads, sidewalks, or other utilities. GPS, with
augmentation, is not affordable.

3.4.1.6 [Property Surveys]{.underline}. GPS position accuracy is
inadequate, particularly in elevation.

3.4.1.7 [Marine Navigation]{.underline}. For some vessels, accuracy is
not sufficient to calculate if the anchor is dragging or if the vessel
is about to enter a tight channel in fog. The lack of horizontal
accuracy, when using stand-alone GPS receivers dictates the use of
differential GPS (DGPS) systems for harbor and approach bathymetric
surveys

8.  [Land Management]{.underline}. Some land management applications
    require extraordinary accuracy. With the current limits on accuracy,
    post processing is required for many applications. Post processing
    is time consuming and expensive. Base stations must be set up and
    maintained; person-hours spent post-processing GPS data nationwide
    within the Bureau of Land Management is immense. Real-time corrector
    broadcasting is unreliable in rough terrain and canopy, and is also
    expensive.

### Impact

3.4.2.1 [Civil Air Navigation]{.underline}. Insufficient position
accuracy will impact safety of flight and shipping in military and civil
sectors. In military applications, it would adversely affect the
accurate delivery of weapons on their intended targets.

Without improved capabilities, existing systems must continue to be
maintained and reliance will continue to be placed on human observation
for rail and automobile navigation, as well as other potential uses of
PVT capabilities. Failure to provide required position accuracy will
result in inefficiencies and potential loss of profitability.

3.4.2.2 [Seismic Surveys]{.underline}. Transporting equipment imposes an
extra logistical burden, sometimes at the end of long supply lines. The
need for a base station crew requires users to return to their starting
point in order to recover the equipment, adding further to fuel loads.

3.4.2.3 [Geodetic Surveys]{.underline}. Users currently have to build
redundancy into survey field programs to make sure they get the right
amount of quality data. It takes two years to arrange an experiment in
the more remote part of Antarctica, so returning to correct data
acquisition mistakes is not practical.

3.4.2.4 [Cable Mapping]{.underline}. While the cost of GPS receivers to
support fiber optic cable mapping may have been acceptable, the manpower
and additional equipment costs associated with setting up differential
base stations was not affordable. Commercially available differential
broadcasts do not cover most of the US, while fiber optic cable covers
the US. With these unresolvable equipment and manpower costs, GPS was
rejected for use in mass fiber optic cable route surveying.

3.4.2.5 [Marine Navigation]{.underline}. Current accuracy of the basic
GPS signal requires that certain Naval applications deploy and utilize
differential GPS. This creates a burden on the operating forces. The
USCG maritime DGPS system is expected to provide position accuracy
better than 10 meters (2 drms) for US harbor and harbor approach areas.
Until DGPS service is declared fully operational by the USCG, signal
availability and accuracy are subject to change due to testing of this
developing service and the uncertain reliability of prototype equipment.

## VELOCITY ACCURACY

### Shortcomings

Current PVT systems do not provide the required velocity accuracies for
some precision guided munitions and heavy artillery users. Due to the
high rate of speed at which these weapons travel, extremely precise
velocities must be provided to precisely compute present positions,
anticipate upcoming navigational vector changes, avoid terrain when
flying in mountainous or hilly environments, as well as assist
integration of external PVT information with internal capabilities. As
fire-and-forget weapon technology improves and matures, and the quantity
of users employing this technology rises, reliance upon more highly
accurate velocity information will likewise increase.

### Impact 

Dichotomies between external and internal systems could result in
navigational errors. Even the smallest difference between expected
position and actual position may result in turns being missed, terrain
being struck, or a target missed resulting in overall mission failure.

## TIMING ACCURACY

### Shortcomings

Current PVT systems do not provide a readily obtainable, highly accurate
time to all users, without the use of additional equipment or equipment
modifications. Further, the impending phaseout of LORAN-C and Omega
systems will reduce timing service backup capability resulting in
greater reliance on GPS.

### Impact

Some command and control communications systems will not operate
properly without sufficient timing accuracy. Many modern systems require
accurate time signals. Timing anomalies can adversely impact the proper
functions of dependent systems. Lack of timing accuracy limits the
capability of secure communications and intelligence. The GPS system
would not be able to provide the required level of timing accuracy
without the support of LORAN and OMEGA. Accurate position and velocity
determination would also be degraded.

## INTEGRITY

### Shortcomings

The basic GPS must be augmented to meet current military and civil
aviation and marine integrity requirements. (Ref 14) Receiver autonomous
integrity monitoring (RAIM), a receiver software program, and DGPS are
two methods of satisfying integrity requirements.

With the current design of the monitor segment of GPS, a satellite may
transmit an unhealthy signal for two to six hours before it can be
detected and corrected. (Ref 14) Current PVT systems are unable to
monitor all signals at all times. Currently, a non-standard code is
transmitted by GPS satellites when an out-of-tolerance PVT signal is
detected. The integrity monitoring system is inadequate to detect/report
signal-in-space errors or problems that do not automatically trigger the
transmission of the non-standard code. Therefore, integrity warning is
not available continuously. Furthermore, it is not possible to meet
future monitoring requirements to detect the transmission of hazardously
misleading information (HMI).

For marine applications, there is no indication when the current PVT
system is not operating correctly.

### Impact

As the number of PVT users increases, there is a greater need to
increase monitoring to detect abnormal transmissions. Without integrity
warning, safety of flight and shipping in both military and civil
sectors will be adversely affected. Aircraft and other systems have no
ability to determine whether navigation systems are working properly
and, therefore, no way to tell whether on-board equipment is giving true
information. Many communications systems, both military and civil,
depend on GPS for timing. Integrity monitoring is critical to continuous
operation of those communications links. Adequate GPS integrity is only
available with RAIM or DGPS. (Ref 19)

## AVAILABILITY

### Shortcomings

There is an ever growing dependence on time-sensitive PVT systems.
Currently, PVT systems do not provide a usable signal to all users at
the precise time needed on an uninterrupted basis. Current systems do
not meet availability needs.

Current systems cannot meet future service availability requirements.
Current methods and procedures for constellation sustainment could
adversely affect availability if a satellite suddenly fails and there is
none immediately available to replace it.

The availability of the current PVT systems, especially the GPS
constellation, does not meet all user requirements (e.g., 100 percent is
specified for railroad collision avoidance). (REF 23)

### Impact

The growth of dependence on PVT systems, particularly GPS, emphasizes
the critical nature of operations and such issues as safety of life. As
more people and systems come to rely on PVT systems for day-to-day
operations, there is a greater likelihood that a catastrophic event will
occur should critical systems fail to operate or provide the necessary
level of accuracy.

## SECURITY

### Shortcomings

3.9.1.1 [Selective Availability]{.underline}. Much of the military
advantage of SA is questionable as SA has been substantially bypassed by
civil and commercial augmentation systems. Even though the PDD declares
national security as the top priority, the PDD stated the intention to
discontinue SA by 2006. The continued use of SA is contrary to the civil
goals of improved performance. (Ref 27) (Ref 45)

3.9.1.2 [Electronic Warfare]{.underline}. Multiple assessments of the
GPS between 1993 and 1997 have all pointed out GPS electronic warfare
shortcomings. There are weaknesses in two areas.

3.9.1.2.1 [Antijam]{.underline}. The GPS AJ capabilities have repeatedly
been identified as being inadequate. GPS performance can be severely
degraded or provide erroneous information in high noise (noise jamming,
multipath, spoofing, etc.) or scintillation environments.

3.9.1.2.2 [Signal Fratricide]{.underline}. The US anticipates attempted
use of the GPS civil frequency as an aid to navigation by hostile
forces. US forces use the civil frequency to acquire and lock-on to
other signals. The US has no capability to deny adversaries the use of
GPS without impacting its own use of the system. Countering this threat
would force the US to jam its own system (signal fratricide) in the area
of conflict and virtually deny friendly use of GPS.

3.9.1.3 [Differential GPS]{.underline}. The most accurate PVT system
currently available is DGPS. There is a risk to using DGPS or
ground-based pseudolites during conflict due to the need for stationary
(and hence vulnerable) reference stations or networks.

3.9.1.4 [Information Warfare]{.underline}. Information Warfare is a
relatively new threat and there are few safeguards in place to ensure
the effective detection, assessment, and response to an IW attack.
Neither military nor civil systems are sufficiently protected against
unauthorized monitoring and intrusion.

3.9.1.5 [Other Shortcomings]{.underline}. Positive train separation (a
railroad anti-collision safety system) requires highly reliable,
precision positioning information. During testing in the Portland,
Oregon area, users experienced loss of GPS signal due to close proximity
of non-railroad RF emitters. Loss of signal was experienced in locations
where there were no known or observed obstructions to the signal path
between the satellite and receiving antenna.

### Impact

Adversarial jamming of the GPS signal would lead to loss of use by US
forces and all other users in the affected area. Adversaries also may
attempt to exploit GPS/DGPS. The lack of appropriate countermeasures to
adversarial use would force the US to jam its own signals, again leading
to loss of use by the US and all other users in the area.

For the military and intelligence communities, information is rapidly
becoming a critical element of modern warfare and information dominance
will be a key goal in future conflicts. This will make US information
systems prime targets for enemy attacks. As information becomes a center
of gravity, it must receive the protection needed to ensure proper
security and uninterrupted availability to the user. Information warfare
could also lead to loss of use of PVT systems due to adversarial action.

Loss of PVT signal for collision avoidance due to RF interference could
result in severe consequences in many military and civil applications.

## CONTINUITY OF SERVICE

### Shortcomings

Continuity of service is a subset of system availability. The current
GPS system does not meet availability requirements (e.g., Cat I approach
and Landings \[Ref 23\]). Therefore, users are concerned the system will
not meet continuity requirements and will not certify GPS as a sole
means.

### Impact

The loss of service at critical times of aircraft precision approach
could have severe consequences, including loss of life.

## COVERAGE

### Shortcomings

Current PVT signals do not provide consistent, equally available
coverage worldwide. Though GPS provides worldwide coverage, under
certain conditions the signal is not available in steep urban valleys,
steep natural valleys, under dense foliage, inside buildings,
underground, underwater, and in space above the orbit of GPS satellites.

For a three-dimensional position fix, a receiver must have at least five
GPS satellites in view or utilize aiding (height, time) in order to
provide RAIM. A minimum of five independent position measurements is
required to support identifying an out of tolerance signal while a
minimum of six independent position measurements is required to identify
and isolate an out of tolerance signal from a single satellite. This
condition is not always satisfied with the existing constellation,
resulting in "[^1]RAIM holes" and limiting GPS use as a supplemental
navigation system.(Ref 19)

There are too few space vehicles (SVs) available 24 hours a day to
support real-time kinematic (RTK) surveying. Current signals cannot
provide service when users are inside buildings or are under significant
forest canopy. RTK carrier phase techniques with "on the fly" integer
ambiguity resolution algorithms require at least 5 satellites with at
least 15 degrees elevation. At high latitudes (above 60 degrees), there
are daily periods when this is not possible to achieve.

Many land navigation applications can not effectively utilize GPS due to
the shadowing problem. This is especially true for applications based on
carrier phase observations.

Assurance of uninterrupted civil access to the GPS signal, for domestic
and international civil sectors, is of paramount importance. As
emergency services and critical navigation services become more reliant
on GPS, an interruption of service will become less tolerable. GPS
coverage can sometimes be less than optimal due to temporary removal of
satellites from service.

Some nations perceive a lack of detailed GPS information being provided
for certification of GPS within those nations.

### Impact

Lack of consistent coverage can impact all users, limiting safety,
access to service, and accuracy. In operations conducted in rural or
urban canyons, as canyon walls become steeper and taller, access to PVT
signals are limited and accuracy decreases.

RTK surveying needs at least 5 SVs. Currently, there are periods when
only 5 SVs are available, so any blockage from trees, buildings, etc,
would preclude RTK operations. Surveyors operating among trees and
buildings experience poor GPS and augmentation signal penetration.

Many potential applications, such as guidance systems for the blind,
cannot tolerate any interruption of positional data and are, therefore,
not supportable with current systems.

This issue is of extreme importance to non-domestic civil users and may
preclude their acceptance of any US provided position/navigation
(pos/nav) system for critical services. An example is a non-domestic
civil defense agency whose responsibility is the evacuation of citizenry
during emergencies. If their city/country might be in a theater of
conflict, use of GPS as their primary posnav system can not be
considered. Obviously, this would also be of concern to domestic civil
defense agencies since they would be forced to rely on units (such as
the National Guard) that possess equipment capable of receiving PPS.

Certification of GPS is sometimes denied by nations that perceive
insufficient information being provided.

## SUPPORTABILITY 

### Shortcomings

The GPS Operational Control Segment is unable to operate all GPS
satellites 100 per cent of the time. Visibility gaps exist because of
ground control site locations. However, the addition of National Imagery
and Mapping Agency (NIMA) ground stations to the control segment will
mitigate this shortcoming.

In order to provide timely assistance to a GPS satellite, the
Operational Control Segment requires a dedicated network of Ground
Antennas and Monitor Stations providing worldwide monitoring and command
and control capabilities. Due to the increased demand on system
reliability and availability, the current network will not be able to
support future PVT requirements.

Some current systems require extensive training of operators and/or
support personnel. (Ref 28)Current ground-based radionavigation systems
require training for operations, spare parts to maintain operations, and
facilities for operations. Budgetary constraints limit the amount of
on-hand spares, making it difficult to perform required maintenance,
both corrective and preventive.

### Impact

Impacts include a lack of service, extra costs, degraded system
accuracy, and reduced availability.

## SURVIVABILITY

### Shortcomings 

The primary threats to current PVT systems are described in Section 2.
The ground control and space segments of current space-based PVT systems
are not survivable.

### Impact 

Denial of PVT information would adversely affect terrestrial forces,
reducing their effectiveness and slowing operating tempo. The use of
these systems will assist in fostering an integrated terrestrial force
that can apply combat power at desired times and places. Loss of that
capability would affect the effectiveness of these forces. (Ref 43)

## INTEROPERABILITY

### Shortcomings

Military and civil users operate with a wide variety of PVT systems and
equipment. Some of these systems are not interoperable. Although GPS is
now widely used, many military platforms are not yet equipped with GPS
receivers.

### Impact

Failure to incorporate interoperability in future PVT systems will
result in proliferation of dissimilar systems and equipment, as well as
extra costs. Not all users could take advantage of significant
technological improvements and, therefore, service and accuracy
improvements.

**SECTION 4**

# Required Characteristics

## INTRODUCTION

Requirements for DoD and civil PVT capabilities are described in this
section in terms of a common set of interrelated required system
characteristics that apply in varying degrees to different classes of
users and missions. These characteristics include: **Position
Accuracy,** **Velocity Accuracy**, **Timing Accuracy, Integrity,
Availability, Security, Continuity of Service, Coverage, Supportability,
Survivability, Interoperability,** and **Affordability.** The
inter-relationships between these characteristics are pointed out in the
characteristic descriptions.

### Required System Characteristics

This section describes the overarching characteristics required to
ensure PVT systems support military and civil needs well into the 21st
Century. A required system characteristic is defined as an overarching
performance or design feature needed to successfully accomplish PVT
missions or tasks. These characteristics encompass primary design, cost,
and risk drivers; and, therefore, need early identification in the
development process. Recommendations for identification of Key
Performance Parameters (KPPs) are provided after the required system
characteristics are explained.

The required system characteristics identified in this section are for
the "system of systems" that will collectively satisfy the system
characteristics articulated here. When individual ORDs are developed and
specific key performance parameters stated, additional required system
characteristics may be added, and some of those identified here may be
modified or combined to better describe specific system requirements.

### Unconstrained Requirements

The requirements detailed here are unconstrained in that they are
generally independent of architectural or system solutions. They are to
be further refined in terms of specific architectural capabilities,
costs, and risks as part of the architecture development process and the
CRD/JROC approval process. Furthermore, it is anticipated that multiple
material solutions will be required to satisfy various levels of
requirements.

### Parameters

Previous discussions of requirements have used average values which
allow for some high errors at various times and locations. The maximum
error the user can tolerate anytime and anywhere needs to be defined to
provide the fidelity to minimize error levels throughout the system.
Also, there have been diverse measures for the characteristics which
leads to confusion about what the requirement is. In a future version,
this document will use one measure for the requirements which will be
stated at the 2 sigma level (95%) where appropriate.

### Phases of Navigation

Some PVT requirements are common to both civil and military users. Both
categories of users must perform the same tasks to navigate on land,
within US airspace, and on waterways. For common tasks, civil and
military requirements are defined in terms of discrete "phases of
navigation." These phases are identified primarily by the
characteristics of the navigational problem as the mobile craft passes
through different regions in its voyage. For example, the aircraft
navigational problem becomes progressively more complex and risky as an
aircraft leaves the enroute environment, approaches an airport, and
finally lands.

### Military Requirements

Operators of military aircraft and sea vessels must meet federal and
international standards when operating in common use areas. Therefore,
civil navigation requirements also apply to military PVT systems. There
are specific military requirements, however, that depend upon mission.
The CJCS MNP provides specific DoD requirements for navigation,
positioning, and timing accuracy organized by primary missions and
functions with specifically related accuracy requirements.

Unique military missions and national security needs may occasionally
impose a different set of requirements. Often, military requirements are
of a continuous nature, i.e., PVT services must equal or exceed tactical
or strategic mission needs at all times in relevant geographic areas,
irrespective of hostile enemy action.

### Multiple Characteristics

There are several requirements that involve more than one of the
required characteristics. New systems must improve PVT accuracy for all
civilian users. These new systems must also improve PVT accuracy,
integrity, and availability to meet Category I requirements and to
replace TACAN sites. The new systems must improve PVT accuracy,
integrity, and availability for Category II and III landings. Further,
new systems must improve PVT accuracy and integrity to meet standards to
qualify as primary and sole means of navigation. Finally, new systems
must improve PVT accuracy, integrity, availability, and protection for
military users in high threat AORs for Category III landings. (REF 12)

4.1.6.1 [Civil Requirements]{.underline}. Numerous civil requirements
have been identified. The PVT system shall, as a minimum, support the
following goals:

1\) Reduced complexity in future PVT augmentation systems due to
reduction in the number of ground stations required.

2\) Cost savings from eventual elimination of many local area
differential systems in conjunction with technical improvements to PVT
system broadcasts.

3\) Lower costs in civil space operations due to enhanced attitude
determination systems and improved spacecraft tracking.

4\) Improvements in atmospheric water vapor content measurements for
meteorological purposes.

5\) Lower costs in surface applications. (REF 12)

4.1.6.2 [Common Use Elements]{.underline}. Common use elements of PVT
systems must be capable of providing operationally acceptable
information simultaneously and instantaneously to an unlimited number of
users. The PVT system should ensure, on an uninterrupted basis, highly
accurate data is provided to the broad range of user applications.

4.1.6.3 [Tailorable Features]{.underline}. There are two other overall
requirements. First, not all requirements will apply equally to all
users or applications. Not all users will have a need for the maximum
accuracy, integrity, availability, security, etc. the new PVT systems
will provide, especially if these features are not affordable. The
features must be "tailorable" for each user. Accessing one feature must
not also require acquiring another feature. While tailorability may be
largely a function of user equipment, it could also be related to signal
structure.

The second overall requirement is closely related to the first. New PVT
systems must provide a signal structure that will allow continued use of
existing user equipment. However, this "backward compatibility" must not
override opportunities to take advantage of new technologies. A period
of dual operations may be necessary. As an example, black and white
television sets can still work with color television signals (backward
compatibility), but no current television receivers will work with
high-definition television signals (dual operations will be necessary).

### Organization

The following sections present the required system characteristics. In
each section, the characteristics are first defined, then the most
stringent quantitative requirements for each characteristic are
summarized in tabular format, broken down by threshold and objective.
Following these tables, the non-numerical requirements that apply to
each required system characteristic are stated. A complete list of
numerical requirements for each required system characteristic is
provided in Appendix A. Finally, the rationale for the identification of
the requirements is presented for each of the characteristics.

## POSITION ACCURACY

### Definition

4.2.1.1 [Position Accuracy]{.underline}. Position accuracy is defined as
the degree of conformance between the estimated or measured position of
a platform at a given time and its true position, specified in three
dimensions. Positioning provides information on the user's location
relative to a specific geospatial reference coordinate system. PVT
system accuracy is usually presented as a statistical measure of system
error and is specified as predictable, repeatable, and relative.

Predictable accuracy: The accuracy of a radionavigation system\'s
position solution with respect to the charted solution. Both the
position solution and the chart must be based upon the same geodetic
datum.

Repeatable accuracy: The accuracy with which a user can return to a
position whose coordinates have been measured at a previous time with
the same navigation system.

Relative accuracy: The accuracy with which a user can measure position
relative to that of another user of the same navigation system at the
same time.

4.2.1.2 [Fix Rate]{.underline}. Fix rate is defined as the number of
independent position fixes or data points available from a system per
unit of time. (REF 12)

4.2.1.3 [Fix Dimension]{.underline}. This characteristic defines whether
a navigation system provides a one-dimensional line of position or a
two- or three-dimensional position fix. The ability of a system to
derive the fourth dimension (time) from the navigation signals is also
included[^2]. (REF 12)

4.2.1.4 [Timeliness]{.underline}. Timeliness is the amount of time
needed by the user to obtain the required accuracy. This value is either
obtained at the actual time of signal reception or is obtained via
post-processing the received signal.

### Requirements

In this and the following sections, the most stringent threshold and
objective requirements are presented for each required system
characteristic. A threshold value is a minimum acceptable operational
value below which the utility of the system becomes questionable. An
objective value is an operationally significant increment above the
threshold. An objective value may be the same as the threshold when an
operationally significant increment above the threshold is not
significant or useful.

The most stringent threshold values of the requirements for the
subsurface, surface, air, and space mediums are in Table 4-1. Military
requirements are shown in **bold**. A complete listing of the
quantitative requirements, both military and civil, for position
accuracy are in Appendix A. The source references are listed in Appendix
D.

**Table** **4-1**. Threshold Requirements for Position Accuracy

+---------+---------+------------------------+------------------------+
|         |         |                        | Source                 |
+---------+---------+------------------------+------------------------+
| Sub     |         | 0.1 m                  | Ref 44                 |
| surface |         |                        |                        |
+---------+---------+------------------------+------------------------+
| Surface |         | **0.3 m**              | **Ref 39**             |
|         |         |                        |                        |
|         |         | 1 mm                   | Ref 44                 |
+---------+---------+------------------------+------------------------+
| Air     |         | **0.2 m**              | **Ref 4**              |
|         |         |                        |                        |
|         |         | 0.8 m                  | FAA                    |
+---------+---------+------------------------+------------------------+
| Space   | GEO +   | **25m/0.1 deg**        | **SATOPS ADT**         |
|         |         |                        |                        |
| (NRT)   | LEO     | 6m/0.1 deg             |                        |
|         |         |                        |                        |
| (Pos/At |         |                        |                        |
| titude) |         |                        |                        |
+---------+---------+------------------------+------------------------+
| Space   | LEO     | **1cm/0.001 deg**      | **SATOPS ADT**         |
|         |         |                        |                        |
| (PP)    | GEO     | **within 72 hrs**      |                        |
|         |         |                        |                        |
|         |         | TBD                    |                        |
+---------+---------+------------------------+------------------------+

Table 4-2 provides the most stringent objective values for the
requirements of each of the different mediums.

**Table 4-2**. Objective Requirements for Position Accuracy

+---------+---------+------------------------+------------------------+
|         |         |                        | Source                 |
+---------+---------+------------------------+------------------------+
| Sub     |         | 1 cm                   | Ref 44                 |
| surface |         |                        |                        |
+---------+---------+------------------------+------------------------+
| Surface |         | **0.3 m**              | **Ref 39**             |
|         |         |                        |                        |
|         |         | 1 mm                   | Ref 44                 |
+---------+---------+------------------------+------------------------+
| Air     |         | **0.1 m**              | **Ref 4**              |
|         |         |                        |                        |
|         |         | 0.8 m                  | FAA                    |
+---------+---------+------------------------+------------------------+
| Space   | GEO +   | **10m/0.01 deg**       | **SATOPS**             |
|         |         |                        |                        |
| (NRT)   | LEO     | 20cm/0.01 deg          | **ADT**                |
|         |         |                        |                        |
| (Pos/At |         |                        |                        |
| titude) |         |                        |                        |
+---------+---------+------------------------+------------------------+
| Space   | LEO     | **1cm/0.001 deg**      | **SATOPS ADT**         |
|         |         |                        |                        |
| (PP)    | GEO     | **within 1 hour**      |                        |
|         |         |                        |                        |
|         |         | TBD                    |                        |
+---------+---------+------------------------+------------------------+

4.2.2.1 [Air Navigation Requirements]{.underline}. The following are
basic requirements for the aviation navigation systems. "Navigation
system" means all of the elements necessary to provide navigation
services to each phase of flight. Figure 4-1 illustrates the
requirements for air navigation. The navigation system must permit the
establishment and the servicing of any practical defined system of
routes for the appropriate phases of flight. New accuracy requirements
will become effective with the implementation of RNP. As navigation
tolerances become more precise, aircraft separation requirements will
decrease and more aircraft will fly closer together in a given airspace.
This drives the requirement for a more frequent, accurate, and automated
aircraft information reporting system. RNP will require an aircraft to
be within a specific number of nautical miles of its cleared position
(cross track and along track 95 per cent of the time). (REF 8)In
conjunction with other flight instruments, the navigation system must in
all circumstances provide information to the pilot and aircraft systems
for performance of the following functions:

-   Continuous track deviation guidance.

-   Continuous determination of distance along track.

-   Continuous determination of position of aircraft.

-   Position reporting.

-   Manual or automatic flight.

Altimetry requirements for vertical separation of 1,000 feet, below
Flight Level (FL) 290, are not expected to change. Increased altimetry
accuracy is needed at and above FL 290 to permit separation less than
the current standard of 2,000 feet. The required future 3 sigma (99%)
value of the aircraft altimetry system error has not been specified, but
it must be accurate enough to support the introduction of 1,000-foot
vertical separation at all flight levels.

(REF19)

![](media/image5.emf){width="4.924305555555556in"
height="3.1222222222222222in"}

Figure 4-1. Air Navigation Requirements

Appendix A provides the position accuracy numerical requirements for
aircraft in the enroute/terminal phase and in the approach and landing
phase of flight. These requirements, taken in total, also tacitly
address collision avoidance.

4.2.2.2 [Marine Navigation Requirements]{.underline}. Marine navigation
requirements are illustrated in Figure 4-2. Appendix A provides position
accuracy numerical requirements for watercraft on inland waterways,
harbor and harbor approach areas, coastal areas, and open oceans. Again,
these requirements essentially address collision avoidance. Additional
collision avoidance requirements, to include icebergs, may be identified
in future revisions.

![](media/image6.emf){width="5.1625in" height="3.4368055555555554in"}

Figure 4-2. Marine Navigation Requirements

4.2.2.3 [Land Navigation Requirements]{.underline}. Land navigation
requirements are illustrated in Figure 4-3. Specific position accuracy
numerical requirements for land applications are provided in appendix A.

![](media/image7.emf){width="4.881944444444445in" height="3.3in"}

Figure 4-3. Land Navigation Requirements

4.2.2.4 [Space Navigation Requirements]{.underline}. Space navigation
requirements are illustrated in Figure 4-4. PVT services for space
applications are applied in two different processing environments:
(REF19)

a\. [Near Real Time]{.underline}. Onboard spacecraft vehicle navigation
support in near real-time applications for position and attitude
determination that are used in the vehicle command and control system.

b\. [Post Processing]{.underline}. Scientific data analysis support
where PVT services will be used to accurately locate instrument position
in space. This type of application generally requires extreme accuracy
in positioning, but in a post processing environment where raw PVT
information is recorded along with instrument observation data aboard
the spacecraft for later processing in a ground facility. This kind of
application typically uses additional information about the PVT system
developed in a ground monitoring environment that provides historical
information precisely locating PVT system information sources. The post
process operation then processes this historical information with the
recorded observation information to derive a very precise position of
the instrument.

![](media/image8.emf)

Figure 4-4. Space Navigation Requirements

4.2.2.4.1 [Satellite Operations]{.underline}. The PVT system shall
support navigation requirements of earth orbiting satellite vehicles and
their payloads in both real-time and in post processing modes of
operation:

a\. [Real-time Requirement]{.underline}:

Support accurate positioning, attitude determination, and precise
coordinated time indication for the purpose of autonomous onboard
navigation of satellite vehicles, independent of earth-based tracking
systems, and during periods of both steady state orbit dynamics as well
as during satellite maneuver operations.

[Threshold Requirement]{.underline}: The PVT system shall provide
real-time information to orbiting spacecraft that will enable on-orbit
position location to within 25 m (3 sigma) per axis for satellites in
geosynchronous earth orbit and decreasing to 6 m (3 sigma) per axis for
satellites in low earth orbit. The PVT system shall support satellite
attitude determination in real-time to an accuracy of 0.1 degree (3
sigma) for each spacecraft axis.

[Objective Requirement]{.underline}: The PVT system shall provide
real-time information to orbiting spacecraft that will enable on-orbit
position location to within 10 m (3 sigma) per axis for satellites in
geosynchronous earth orbit and decreasing to 20cm (3 sigma) per axis for
satellites in low earth orbit. The PVT system shall support satellite
attitude determination in real-time to an accuracy of 0.01 degree (3
sigma) for each spacecraft axis.

b\. [Post Processing Requirement]{.underline}:

Support precise positioning of satellite payload instruments through the
processing of data observed and recorded onboard the satellite.

[Objective Requirement]{.underline}: The PVT system shall supply the
necessary data products for post processing of the recorded data that
will enable instruments to be located to an accuracy of 1 cm (3 sigma)
in each axis within 72 hrs of data recording.

[Threshold Requirement]{.underline}: The PVT system shall supply the
necessary data products for post processing of the recorded data that
will enable instruments to be located to an accuracy of less than 1 cm
(3 sigma) in each axis within 1 hr of data recording.

Note: Consideration should also be given to Metric Tracking Upgrade
requirements for launch vehicles.

4.2.2.5 [Military Navigation Requirements]{.underline}. Military
navigation requirements are illustrated in Figure 4-5. Future PVT
systems must be capable of providing the signals to meet the
requirements for JPALS, Global Air Traffic Management (GATM), and other
new systems as they become operational.

An ideal military positioning/navigation capability should be totally
self-contained so that military platforms are capable of performing all
missions without reliance on information from outside sources. The
nature of military operations requires that essential navigation
services be available, with the highest possible confidence that these
services will equal or exceed performance requirements. This, among
other considerations, necessitates a variety of navigational techniques
and redundant installations on weapon system platforms.

While reliance on a single PVT system is unwise, redundant or backup
systems for military operations should not be more vulnerable,
less-capable external systems. Rather, they must be reliable, accurate,
self-contained systems uniquely tailored to match platform mission
requirements.

![](media/image9.emf){width="4.533333333333333in"
height="2.8993055555555554in"}

**Figure** **4-5. Military Navigation Requirements**

4.2.2.6 [Precision Munitions]{.underline}. Improved accuracy is required
so US forces can use PVT systems and reduce dependence on high cost
alternative guidance systems.

4.2.2.7 [Signal Power]{.underline}. Future PVT systems shall provide the
average received signal with sufficient power to adequately support all
users.

4.2.2.8 [Surveying]{.underline}. Surveying applications can include such
operations as construction, boundary determination, science and
research, environmental protection, and agriculture where a generic
geographical layout is desired. Requirements exist today for accuracies
down to 1 mm, both horizontal and vertical, for some of these
applications. Future PVT systems must support one meter horizontal
accuracy in real-time, based solely on broadcast information with no
augmentation. Near real-time accuracies should be available down to 2 cm
horizontal and 4 cm vertical. PVT systems should also provide orbit,
atmosphere, and clock corrections either in real-time, or within 24
hours. Although users are able to use augmentation systems for certain
accuracies today, a desire has already been identified for future PVT
systems to support real-time centimetric accuracy without augmentation.

4.2.2.9 [Response Time]{.underline}. Certain tracking applications
require responsive positioning and navigation services. Applications
such as law enforcement, environmental and marine research, search and
rescue, automated vehicle movement, marine navigation, mine warfare, and
many other military applications require this information in near
real-time in order to complete their missions safely and efficiently.
Response time on the order of 1 to 5 seconds is often critical in these
applications.

4.2.2.10 [Law Enforcement]{.underline}. To support law enforcement
requirements, there is a need to provide 1 meter accuracy in tracking
individuals wearing court ordered "ankle bracelets." This requirement
extends to coverage in buildings and tunnels. Communications operators
need to locate questionable RF emitters. Using a PVT system to assist
this effort should provide accuracy to less than one meter.

4.2.2.11 [Oil/Mineral Studies]{.underline}. There is a need for greater
position accuracy than currently provided by DGPS systems for civil
users over larger geographical areas.

### Rationale.

Many users require substantially better position accuracy than can be
provided by the current GPS SPS or PPS. Enhanced accuracy will improve
the usefulness of any PVT system thus expanding applications and
potential economic benefit. (REF 23)

4.2.3.1 [Air Navigation]{.underline}. Civil aircraft navigation
performance requirements are determined by the phase of flight and
aircraft relationship to terrain, to other aircraft, and to the air
traffic control process. Aircraft separation criteria, established by
the FAA, take into account limitations of the navigational service
available and, in some airspace, the Air Traffic Control surveillance
service. Aircraft separation criteria are influenced by the quality of
navigational service, but are significantly affected by other factors as
well. The criteria relative to separation require a high degree of
confidence that an aircraft will remain within its assigned volume of
airspace. The dimensions of this volume are determined, in part, by a
stipulated probability that performance of the navigation system will
not exceed a specified error.

4.2.3.2 [Marine Navigation.]{.underline} Civil marine navigational
performance requirements are determined by the general type and size of
the vessel, the activity in which it is engaged, and the geographic
region in which it operates. Safety requirements for navigation
performance are dictated by the physical constraints imposed by the
environment and the vessel, and the need to avoid the hazards of
collision, ramming, and grounding. The pilot of a vessel in restricted
waters must direct its movement with great accuracy and precision to
avoid grounding in shallow water, hitting submerged/partially submerged
rocks, and colliding with other craft in congested waterways. Unable to
turn around, and severely limited in the ability to stop to resolve a
navigational problem, the pilot of a large vessel (or a tow boat and
barge combination) may need accuracy to within a few feet while
navigating in this environment. Economic considerations may lead to
additional requirements. For example, navigation accuracy (beyond that
needed for safety) is particularly important to the economy of large
ships with high hourly operating costs. For fishing and oil exploration
vessels, the ability to locate precisely and return to productive or
promising areas while avoiding underwater obstructions or restricted
areas provides important economic benefits. Search and Rescue
effectiveness is similarly dependent on accurate navigation in the
vicinity of a maritime distress incident.

In such activities as marine scientific research, hydrographic
surveying, commercial fishing, and petroleum or mineral exploration, as
well as in Navy operations, there may be a need to establish position in
the coastal area with much higher accuracy than that needed for safety
of general navigation.

For safe general navigation under normal circumstances, requirements for
the accuracy and frequency of position fixing on the high seas are not
very strict. These minimum requirements permit reasonably safe oceanic
navigation, provided the navigator understands and makes allowances for
the probable error in navigation, and provided that more accurate
navigational service is available as land is approached.

Economic efficiency in transoceanic transportation, special maritime
activities, and safety in emergency situations requires or benefits from
navigational accuracy higher than that needed for safety in routine,
point-to-point ocean voyages. (REF19)

For system planning, the USG seeks to satisfy minimum safety
requirements for each phase of navigation and to maximize economic
utility of service for users. Since the vast majority of marine users
are required to carry only minimal navigational equipment, and even then
do so only if persuaded by individual cost/benefit analysis, this
governmental policy helps to promote maritime safety through a
simultaneous economic incentive. The USG does not recognize an absolute
commitment to satisfy these requirements, but does endeavor to meet them
if their cost can be justified by benefits which are in the national
interest.

4.2.3.3 [Land Navigation]{.underline}. Civil land navigation
requirements are driven by many different applications. PVT systems are
used for automatic vehicle location, automated vehicle monitoring,
automated dispatch, surveying, roadway navigation in general
transportation, emergency services, and the transportation of hazardous
materials.

Since 1980, geodetic surveyors have used GPS carrier phase signals, both
L1 and L2, to measure baseline vectors to the centimeter-level of
accuracy and occasionally to the millimeter level. Today, surveyors
routinely measure 5, 50, 500, and 5000 kilometer (km) baselines to
centimeter accuracy in all components.

The Environmental Protection Agency (EPA), for example, has requirements
for 3-5 meters accuracy for location of sites (factories, landfills,
sewage plants, etc.), 3-5 meters for location of items (outfalls, wells,
stacks, etc.), submeter for sampling points (especially soils,
sediments), and millimeter for water levels (especially groundwater in
level land). The EPA also needs to be able to do field work with 1-5
minute data collection times.

4.2.3.4 [Space Navigation]{.underline}. Space navigation performance
requirements are derived from a need to accurately track spacecraft. The
National Aeronautics and Space Administration (NASA) intends to use GPS
as its operational system on future missions. The International Space
Station (ISS) is being designed to use GPS for navigation, attitude
determination, and UTC distribution. GPS will support onboard ISS system
control functions as well as various experimenter data capture
processes. By 2000, the Space Shuttle will use GPS in both its on-orbit
operations and the descent phases of flight, and may use GPS during the
ascent phase shortly after the turn of the century. NASA, the military,
and the commercial space industry use GPS for earth observation, space
research, and communications to reduce costs of operations, as well as
enable new levels of on-orbit autonomy.

Where scientific data position accuracy is required with precision
greater than that readily available from the GPS receiver onboard a
spacecraft, a refinement of post-pass orbit data is used. NASA has
developed post-pass orbit data processing techniques using GPS on the
TOPEX/POSEIDON satellite that provides high accuracy. In order to
accomplish this, GPS range and phase observables must be downlinked with
scientific data.

In addition to NASA, US industry plans to use GPS for satellite
navigation, attitude determination, and precise time. The civil use of
GPS for satellite operation has already begun and will accelerate in the
near future as many of the new Low Earth Orbit (LEO) communication
satellite constellations make use of GPS in their satellites.

4.2.3.5 [Military Navigation]{.underline}. Military navigation
performance requirements include those civil requirements necessary to
operate in nationally and internationally controlled airspace, on the
high seas, in coastal areas, and in space. Additionally, military forces
must be prepared to conduct operations anywhere in the world, in the
air, on and under the sea, on land, and in space. Military planning must
also consider operations in hostile environments. Future PVT systems
must be capable of providing the signals to meet the requirements for
JPALS, GANS, and GATM as they become operational.

4.2.3.6 [Precision Munitions]{.underline}. Improved accuracy would
improve the safety, increase effectiveness, and reduce costs of
precision munitions.

4.2.3.7 [Fix Rate]{.underline}. Use of PVT systems by dynamic platforms
(high performance aircraft, missiles) requires continuous
position/velocity fixes to meet the accuracy requirements of the
platform.

Reference: CJCSI 6130.01, Enclosure B. (REF 12)

4.2.3.8 [Surveying]{.underline}. There is a need for surveyors in remote
areas to be able to use only the broadcast signals in areas where there
is no augmentation available. This capability is necessary to support
seismic surveys, Geographical Information Systems data acquisition, land
navigation, and mapping projects. One millimeter resolution is necessary
to support soil movement detection. There is also a need for clock,
orbit and atmospheric correction data for post-processing to support
high accuracy users in remote areas. Real-time centrimetric accuracy is
needed to support precision farming, road surveying, fiber optic cable
mapping, and cartography.

## VELOCITY ACCURACY

### Definition

Velocity is the time rate of linear motion in a given direction.
Velocity accuracy is the degree of conformance between the estimated or
measured velocity of a platform at a given time and its true velocity.
For users of the PVT system, velocity is derived from the Doppler shift
of received signals.

### Requirements

The most stringent threshold values for velocity accuracy requirements
are in Table 4-3. A complete listing of the requirements, both military
and civil, for velocity accuracy are in Appendix A. Where specified,
direction accuracy is provided in parentheses.

Table 4-3. Threshold Requirements for Velocity Accuracy

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            | **0.013 m/sec          | **Ref 39/35**          |
|                    | (0.0225°)**            |                        |
|                    |                        | Ref 44                 |
|                    | 0.05 m/sec             |                        |
+--------------------+------------------------+------------------------+
| Air                | **.03 km/hr**          | **Ref 39**             |
|                    |                        |                        |
|                    | 2 m/sec                | FAA                    |
+--------------------+------------------------+------------------------+
| Space              | **0.001 m/sec**        | **SATOPS ADT**         |
|                    |                        |                        |
|                    | 0.0001 m/sec           | NASA JPL               |
+--------------------+------------------------+------------------------+

Table 4-4 provides the most stringent objective values for the
requirements of each of the different mediums.

Table 4-4. Objective Requirements for Velocity Accuracy

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            | **0.013** **m /sec     | **Ref** **39/35**      |
|                    | (0.005°)**             |                        |
|                    |                        | Ref 44                 |
|                    | 0.4 m/sec              |                        |
+--------------------+------------------------+------------------------+
| Air                | **0.03 m/sec**         | **Ref 39**             |
|                    |                        |                        |
|                    | 2 m/sec                | FAA                    |
+--------------------+------------------------+------------------------+
| Space              | **\< 0.0001 m/sec**    | **SATOPS ADT**         |
|                    |                        |                        |
|                    | \< 0.0001 m/sec        | SATOPS ADT             |
+--------------------+------------------------+------------------------+

Support of Satellite Operations imposes the following requirements:

[Threshold Requirement]{.underline}: The PVT system shall support
velocity determination by satellite-based users such that onboard
systems shall be able to determine the satellite's velocity to within
0.1 cm/sec. (3 sigma) per axis in real-time.

[Objective Requirement]{.underline}: The PVT system shall support
velocity determination by satellite-based users such that onboard
systems shall be able to determine the satellite's velocity to within
0.1 mm/sec. (3 sigma) per axis.

### Rationale

Determination of accurate velocity is required to provide accurate
forecasts of arrival time.

## TIMING ACCURACY

### Definition

Timing accuracy refers to the concept of what time the receiver thinks
it is vs. what UTC (USNO) time is. There are two measures associated
with timing accuracy. The first refers to the degree of conformance
between the estimated or measured time and UTC (USNO). Time transfer
(the transmission of a time signal over a communications medium) is used
to provide accurate time signals to remote users. The second measure
refers to the precision in determining the interval of time associated
with an event. To accomplish this task, an event's start and stop time
is measured according to a precise time signal. Variables associated
with timing accuracy include inherent clock accuracy, accuracy of the
time transfer procedure, and the quality of the receiver.

### Requirements

The most stringent threshold values for timing accuracy requirements are
in Table 4-5. A complete listing of the requirements, both military and
civil, for timing accuracy are in Appendix A.

Table 4-5. Threshold Requirements for Timing Accuracy

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            | **\<10 nsec (1         | **Ref 4**              |
|                    | sigma)**               |                        |
|                    |                        | Ref 44                 |
|                    | 10 nsec                |                        |
+--------------------+------------------------+------------------------+
| Air                | **\<10 nsec (1         | **Ref 4**              |
|                    | sigma)**               |                        |
|                    |                        | FAA                    |
|                    | 5 msec                 |                        |
+--------------------+------------------------+------------------------+
| Space              | **20 nsec**            | **Ref 12**             |
|                    |                        |                        |
|                    | 0.1 nsec (1 sigma)     | NASA JPL               |
+--------------------+------------------------+------------------------+

Table 4-6 provides the most stringent objective values for the
requirements of each of the different mediums.

Table 4-6. Objective Requirements for Timing Accuracy

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            | **\<10 nsec (1         | **Ref 4**              |
|                    | sigma)**               |                        |
|                    |                        | Ref 44                 |
|                    | 1 nsec                 |                        |
+--------------------+------------------------+------------------------+
| Air                | **\< 10 nsec (1        | **Ref 4**              |
|                    | sigma)**               |                        |
|                    |                        | FAA                    |
|                    | 5 msec                 |                        |
+--------------------+------------------------+------------------------+
| Space              | **0.01 nsec PP**       | **SATOPS ADT**         |
|                    |                        |                        |
|                    | 0.01 nsec PP           | SATOPS ADT             |
+--------------------+------------------------+------------------------+

4.4.2.1 [Timing Reference]{.underline}. PVT systems must provide
reliable, highly accurate common timing reference to users/customers.
The systems must ensure timing accuracy and stability. Frequent timing
accuracy evaluation by the operating authority is necessary to ensure
the error is kept within limits.

4.4.2.2 [Continuous Link]{.underline}. The PVT system must have a
continuous link to UTC (USNO) as the timing standard. This is necessary
to ensure any "offsets" in time are recognized and corrected. The PVT
time source must be tied to UTC (USNO) to support users who rely on a
local atomic frequency standard to check reliability of the PVT signal,
or who plan to mix PVT-timed elements of a network with elements timed
from other sources. Other users who are affected by PVT offsets from UTC
(USNO) are astronomers, who, for example, use PVT systems as a time
source to observe the rotation rates of pulsars.

4.4.2.3 [Clock Offset Error]{.underline}. Regardless of the time
transfer technique, the transmission medium typically introduces delays
in the transfer, resulting in a time received by the user that is
actually offset from UTC (USNO) time. In order to enable accurate
positioning, and the relative clock synchronization required for
communication and geolocation, it is necessary to accurately communicate
this time offset of PVT clocks to the users so that corrections can be
made at the receiving end and the required accuracy can be achieved.

4.4.2.4 [Timing Support]{.underline}. The PVT Control Segment shall
maintain its own time reference. However, to correctly relate that time
to UTC (USNO), near real-time estimates of the PVT-UTC bias offset must
be obtained from the USNO. This data will be used by the PVT Control
Segment for time transfer and time steering calculations. Threshold:
Once per 24 hours. Certain users require more accurate emitter location
information to more accurately measure time offsets.

4.4.2.5 [Satellite Operations]{.underline}.

[Threshold Requirement]{.underline}: The PVT system shall provide
real-time information to earth orbiting satellites such that the clock
offset error between UTC and the satellite-based user receiver time does
not exceed 25 nanoseconds (nsec) (3 sigma).

[Objective Requirement]{.underline}: The PVT system shall provide
real-time information to earth orbiting satellites such that the clock
offset error between UTC and the satellite-based user receiver time does
not exceed 0.01 nsec (3 sigma).

### Rationale

PVT uses for timing have increased over the years, as have the
requirements for increased accuracy. Uses have been developed to provide
highly accurate timing for non-associated electronic systems, wildlife
migratory studies, power network timing, and time-synchronization
between systems. One national telephone company uses Loran-C and GPS
extensively for communication network synchronization. Other uses have
developed for accurate timing obtained from the PVT signals such as
network synchronization, validation of information transmission, tagging
of data for time-delayed transfer to data ports, medical and scientific
laboratory tests, satellite applications, and fleet monitoring.
Navigation is a function of the timing signal, since one nsec equates to
about 30 centimeters in distance or about one foot. More uses for the
accurate and available signal obtained from the current PVT systems are
continually being developed.

## INTEGRITY 

### Definitions

4.5.1.1 [Integrity]{.underline}. There are two aspects that must be
addressed by the integrity requirement: 1. System Outage Warning: The
ability of the system to provide timely warning to users when the
system's signals should not be used by the users for PVT purposes in a
part of the user's coverage domain. 2. Malfunctioning Component
Determination: The ability of user equipment to determine when a
component of the PVT system should not be used as an information source
for PVT purposes.

4.5.1.2. [Availability of Integrity]{.underline}. Availability of
integrity is the percentage of time that the system provides data at the
defined level of integrity or provides warning that the level of
integrity has dropped below the defined level.

### Requirements

All users shall have the ability to monitor the integrity of the PVT
system every day, 24 hours per day , in real time throughout the user's
coverage domain. PVT System Outage Warnings shall be generated by the
PVT system and shall indicate the portion of the user coverage domain to
which the warning applies. User determination of a malfunctioning PVT
system component may be accomplished through either notification by the
PVT system or through passive monitoring of the system by the user
equipment, or a combination of both. The most stringent threshold
requirements for determination of malfunctioning PVT system components
are given in Table 4-7, and represent the time between component
malfunction as a PVT information source and determination of the
malfunction in the user equipment (user notification as required by
application).

Table 4-7. Threshold Requirements for Integrity

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            | Time to alarm: 10 sec  | Ref 44                 |
+--------------------+------------------------+------------------------+
| Air                | **HMI: 4x10^-8^ per    | **Ref 4**              |
|                    | approach**             |                        |
|                    |                        | FAA                    |
|                    | **Alarm Limit: 1.1m**  |                        |
|                    |                        |                        |
|                    | **Time to Alarm: 1     |                        |
|                    | sec**                  |                        |
|                    |                        |                        |
|                    | 1-2x10^-9^ per         |                        |
|                    | approach               |                        |
|                    |                        |                        |
|                    | Time to alarm: 1 sec   |                        |
+--------------------+------------------------+------------------------+
| Space              | **Monitor 24 hr/day,   | **SATOPS ADT/SWC**     |
|                    | 100 % monitoring below |                        |
|                    | 10,000km**             | SATOPS ADT             |
|                    |                        |                        |
|                    | **Time to Alarm: 6     |                        |
|                    | sec**                  |                        |
|                    |                        |                        |
|                    | Monitor 24 hr/day      |                        |
|                    |                        |                        |
|                    | Time to alarm: 6 sec   |                        |
+--------------------+------------------------+------------------------+

The most stringent objective requirements for determination of
malfunctioning PVT system components are given in Table 4-8, and
represent the time between component malfunction as a PVT information
source and determination of the malfunction in the user equipment (user
notification as required by application.

**Table** **4-8. Objective Requirements for Integrity**

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            | Time to Alarm: 5 sec   | Ref 44                 |
+--------------------+------------------------+------------------------+
| Air                | **HMI: 4x10^-8^ per    | **Ref 4**              |
|                    | approach**             |                        |
|                    |                        | FAA                    |
|                    | **Alarm Limit: 1.1m**  |                        |
|                    |                        |                        |
|                    | **Time to Alarm: 1     |                        |
|                    | sec**                  |                        |
|                    |                        |                        |
|                    | 1-2x10^-9^ per         |                        |
|                    | approach               |                        |
|                    |                        |                        |
|                    | Time to Alarm: 1 sec   |                        |
+--------------------+------------------------+------------------------+
| Space              | **Monitor 24 hrs/day** | **SATOPS ADT**         |
|                    |                        |                        |
|                    | **Time to Alarm: 3     | SATOPS ADT             |
|                    | sec**                  |                        |
|                    |                        |                        |
|                    | Monitor 24 hr/day      |                        |
|                    |                        |                        |
|                    | Time to Alarm: 3 sec   |                        |
+--------------------+------------------------+------------------------+

4.5.2.1 [Integrity Monitoring]{.underline}.

4.5.2.1.1 [PVT System]{.underline}. PVT systems shall provide an
integrity system[^3] that will interpret signal information and
determine if the signal information exceeds the specified performance
criteria for that particular phase of operation and then provide timely
warning when an out of tolerance situation occurs. The definition of
timely warning varies depending on the nature of vehicle involved and
its stage of navigation. PVT systems are required to perform worldwide
monitoring of their signals and report outages/discrepancies and
interference. Integrity thresholds are specified as a probability rate
of HMI at a specific alarm limit and time to alarm required by the
operation being performed. The integrity function must meet the
availability and continuity requirements stated in Sections 4.5 and
4.12, respectively for controlled airspace. Both detection and alarm
rate requirements must be met at all times.

4.5.2.1.2 [User Equipment]{.underline}. A user must be capable of
determining which parts of the system should not be used as a particular
PVT System element may be malfunctioning, not the entire PVT System.
(REF NASA) UE may provide a RAIM capability, with Fault Detection and
Exclusion (FDE). When RAIM FDE is being used as the primary integrity
source, the system shall alert the operator of projected service outages
over the planned route.

(REF 32)

4.5.2.2 [PVT Signal Monitoring Capability]{.underline}. PVT system
control segments shall have the ability to monitor signals passively on
a continuous worldwide basis. Each PVT emitter shall be monitored 24
hours per day. (REF 12) Some systems require real- time signal
monitoring. (NRO req)Global monitoring coverage is necessary to ensure
the navigation signals transmitted meet performance criteria. Updates of
system status should be made more frequently (less than one minute) than
with current systems. Safety of flight requirements have the most
stringent criteria for precise signal monitoring by augmentation systems
within defined areas. As a minimum, this criteria includes:

\(a\) Enroute Through Non-precision Approach: When navigating in
controlled airspace, UE shall use any augmentation signals provided to
meet integrity requirements for that airspace. The system shall alert
the user when the controlled airspace requirements cannot be met.

(REF 32)

1\) Probability of HMI

2\) Time to Alarm

3\) Continuity of Navigation

4\) Continuity of Fault Detection

\(b\) Category I Precision Approach Aviation, Precision

1\) Probability of HMI

2\) Time to Alarm

3\) Continuity

\(c\) Category II Approach

1\) Probability of HMI

2\) Time to Alarm

3\) Continuity

\(d\) Category III Approach

1\) Probability of HMI

2\) Time to Alarm

3\) Continuity

\(e\) Probability of Undetected Error

\(f\) Interference

(Note: Specific values for these requirements are listed in Appendix A.)
(REF 12)

4.5.2.3 [Precision Landing]{.underline}. For the military, the precision
approach integrity requirements are to be defined as part of the JPALS
program. Thus, the precision approach values listed in Table B-1 of the
MNP prescribe only unaugmented GPS levels. Integrity requirements
supporting precision landing will be defined in the JPALS ORD.(REF 12)
Civil precision approach requirements are levied in accordance with the
FRP.

4.5.2.4 [Warning to Users]{.underline}**.** Under Title 14 USC 81-83,
operators of aids to navigation are required to keep the navigation aid
in good working order, discover failure, and give warning. PVT systems
shall ensure timely warning to users when specific emitters and/or the
system is not available for use. (REF 12)

4.5.2.5 [Maritime Users]{.underline}. Maritime users also need to know
whether the PVT system is operating properly.

4.5.2.6 [Space-based Users Interference and Warning]{.underline}. PVT
systems must provide an alternate method to ensure a satellite-based
user's navigation system can continue to operate in the presence of
interference on a particular radio frequency used to obtain PVT
information. Since many satellite-based users will not be military, this
method should be unencrypted. Also, an alerting scheme for
malfunctioning PVT systems must be available to satellite-based users
that will enable onboard systems to determine which PVT information
sources should not be used due to malfunction of the information source.
Space-based PVT user systems shall be notified within 6 seconds of any
abnormalities identified in a PVT system by the PVT monitoring system.

4.5.2.7 [Other Users]{.underline}. Although impact of anomalies are not
safety issues for some users, system failures can have such impact as
increased operations cost and region-wide power and communications
outages. Future PVT systems should provide the capability to advise
users of the PVT system of pending and verified PVT system anomalies.

To support satellite operations, the PVT system shall enable the
elimination of erroneous information sources from use by the
satellite-based user equipment within 6 seconds of the broadcast of the
erroneous information.

### Rationale

PVT information is relied upon for safety of life and mission
accomplishment (in this context, mission refers to military, commercial,
scientific or other mission). In many applications, especially those
involving safety of life, it is essential that the end user be notified
promptly of system failures. (REF 23) Therefore PVT systems must either
positively notify operators when a PVT component fails or is emitting
out of tolerance signals or provide a process that will enable user
equipment to self-determine that a PVT information source component has
malfunctioned. Operators cannot be expected to recognize failures merely
by recognizing incorrect navigation information. Integrity monitoring
performance depends upon how critical the PVT service is to safety and
mission accomplishment.

4.5.3.1 [Aviation]{.underline}. Satisfies integrity requirements as
stated in the FRP and the MNP.

Reference:

a\. 1994 CJCSI 6130.01

b\. 1994 FRP, appendix A, paragraph A.2.9J

c\. Navstar GPS PMD, 3 Nov 92. (REF 12)

4.5.3.2 [Navigation Signal Monitoring Capability]{.underline}. A
monitoring capability is required to allow the control segment to detect
and correct satellite signal anomalies. To support civil requirements
for warning within six to ten seconds, continuous worldwide monitoring
is required.

Reference: PMD 4075(33)/PE35164F/35165F, 26 May 94. (REF 12)

4.5.3.3 [PVT System]{.underline}. The threshold value is a necessary
system segment allocation to enable an integrity system to be developed
to meet an overall requirement for the average probability of HMI from
all causes. (REF 12)

4.5.3.4 [Warning to Users]{.underline}. By law, operators of
radionavigation aids are required to provide timely warning to users
when the system will not be available for use.

Reference: Title 14, USC 81-83 . (REF 12)

4.5.3.5 [Space-based Users Interference and Warning]{.underline}. The
future use of PVT systems for spacecraft critical functions requires PVT
signals be made available for operations throughout the satellite-based
user's domain. Therefore satellite-based users must be capable of
dealing with signal interference or inaccurate information transmissions
from a PVT system. This is especially critical during satellite
maneuvering or launch operations.

## AVAILABILITY

### Definition 

4.6.1.1 [Availability]{.underline}. Availability is defined as the
percentage of time PVT services are adequate to permit all requirements
to be met including determination of position, velocity, or time to a
specified level of accuracy over a 24 hour period. It is a function of
both the physical characteristics of the environment and the technical
characteristics of the PVT systems and facilities.

4.6.1.2 [Service Availability]{.underline}. Service Availability is the
percentage of time that a user has an adequate number of signals
available to allow position, velocity, and time determination at the
required accuracy level over a specified time interval and within the
coverage domain of the user application.

4.6.1.3 [Service Reliability]{.underline}. The reliability of a
navigation system is a function of the frequency with which failures
occur within the system. It is the probability that a system will
perform its function within defined performance limits for a specified
period of time under given operating conditions. (REF 12)

### Requirements

PVT systems must be available when they are needed. Specific
applications may require some systems only be available during certain
conditions such as night, adverse weather, etc. Other applications, such
as civil and military space systems, may require that the PVT signal be
available continuously. For example, there is a current need for 100 per
cent availability to support time transfer users. System availability
should be specified in appropriate system requirements and
specifications documents.

The most stringent threshold values for availability requirements are in
Table 4-9. A complete listing of the requirements, both military and
civil, for availability are in Appendix A.

Table 4-9. Threshold Requirements for Availability

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            | 100 % (of 24 hours)    | Ref 44                 |
+--------------------+------------------------+------------------------+
| Air                | **99.999% (of 24       | **Ref 4**              |
|                    | hours)**               |                        |
|                    |                        | FAA                    |
|                    | 99.999% of 24 hours    |                        |
+--------------------+------------------------+------------------------+
| Space              | **100% over 24 hours** | **SATOPS ADT**         |
|                    |                        |                        |
|                    | 100% over 24 hours     | SATOPS ADT             |
+--------------------+------------------------+------------------------+

Table 4-10 provides the most stringent objective values for the
requirements of each of the different mediums.

Table 4-10. Objective Requirements for Availability

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            | 100% of 24 hours       | Ref 44                 |
+--------------------+------------------------+------------------------+
| Air                | **99.999% (of 24       | **Ref 4**              |
|                    | hours)**               |                        |
|                    |                        | FAA                    |
|                    | 99.999% of 24 hours    |                        |
+--------------------+------------------------+------------------------+
| Space              | **100% over 24 hours** | **SATOPS ADT**         |
|                    |                        |                        |
|                    | 100% over 24 hours     | SATOPS ADT             |
+--------------------+------------------------+------------------------+

4.6.2.1 [Power Grids]{.underline}. Power grids are very large systems
that can cover many states and provinces. GPS is used to synchronize the
analog-to-digital sampling of voltage and current signals at substations
and power plants located tens or hundreds of kilometers apart. GPS is
the only practical timekeeping service that can be received in the
electrically-noisy substations and power plants. Timing accuracy
requirements are modest at the one microsecond level, but 100%
availability and reliability are required. In the future, decisions on
whether to disconnect major power lines or sacrifice electrical service
to a city to save the power grid may be made on measurements that use
PVT systems to synchronize measurements.

4.6.2.2 [Communications]{.underline}. Include a (one-way) message
component for communication between the system operator and the civilian
users. It is not reasonable to assume that millions of civilian users
will monitor or even be aware of communication services such as Notice
to Mariners. Therefore, any important communication from the system
operator to the average user must be provided by the PVT message itself.

4.6.2.3 [Landing Systems]{.underline}. PVT signals should support 99.9%
availability (that is, approximately that of ILS) of precision approach
functionality at a given location on earth up to 70 degrees latitude
(area where precision approaches to Cat III are conducted). PVT signals
should support 99.999% availability on a wide-area basis (that is, the
failure that took out the primary airport cannot also take out the
alternate). The probability that this precision approach functionality
will be lost once the airplane is below 200 feet must be on the order of
1.08E-8 per approach at a given runway end, or about 0.5E-7 per hour on
that runway end.

### Rationale

The prime reason for the stringent requirements presented in this CRD is
safety of life. (REF 23) The mix of current PVT systems provide a very
high availability which is necessary to provide continued support to the
wide variety of users.

## SECURITY

### Definition

Typical man-made threats to a PVT system are detailed in Section 2 and
include sabotage, terrorism, physical destruction, jamming, and IW.

4.7.1.1 [Security]{.underline}. Security is defined as a condition that
results from the establishment and maintenance of protective measures
that ensure a state of inviolability from hostile acts or influences.
Security also includes measures that prevent the hostile use of PVT
services without unduly disrupting or degrading civilian uses.

4.7.1.2 [Interference/Jamming]{.underline}. Interference/jamming is the
deliberate/non-deliberate radiation, re-radiation, or reflection of
electromagnetic energy for the purpose of preventing or reducing an
enemy's effective use of the electromagnetic spectrum, and with the
intent of degrading or neutralizing the enemy's combat capability. (CJCS
MOP 6, Appendix B)

4.7.1.3 [Spoofing]{.underline}. Spoofing is the deliberate radiation,
re-radiation, alteration, suppression, absorption, denial, enhancement,
or reflection of electromagnetic energy in a manner intended to convey
misleading information to an enemy or to enemy electromagnetic-dependent
weapons, thereby degrading or neutralizing the enemy's combat
capability. (CJCS MOP 6, Appendix B)

### Requirements

System security measures are required to assure mission capabilities
during peacetime, war, and intermediate levels of conflict. Transmission
of classified or sensitive information must be protected through the use
of secure voice and data and control of computer processing operations.
(REF 12)

4.7.2.1 [Overarching]{.underline}. The PVT system must be able to meet
user performance requirements in the presence of degradation,
disruption, denial, hostile access, or exploitation by adversaries or
natural phenomena. The PVT system must not be vulnerable to any threat
that could cause total loss of the PVT service.

4.7.2.2 [Protect Aviation Information Systems]{.underline}. A security
system must be established that will provide a high level of protection
for all aviation information systems. Information systems critical to
aircraft, air traffic control and airports should be protected.

4.7.2.3 [Propagation Anomalies]{.underline}. Military PVT systems must
be free from signal fades or other propagation anomalies within the
operating area. The systems must be resistant to both natural
disturbances and hostile attacks. The PVT system must be capable of
operating through scintillation and severe ionospheric disturbances.
(REF 12)

4.7.2.4 [Information Control]{.underline}. The system must be capable of
preventing or limiting accurate PVT information to all hostile users in
an AOR.

4.7.2.5 [Jam Resistance]{.underline}. PVT shall have a jam and other
interference resistance capability to provide continuous PVT information
to the user. Support is defined as detecting, acquiring, maintaining,
re-acquiring or providing PVT information to the platform. *Master
Navigation Plan*, CJCSI 6130.01, dtd 20 May 1994 (REF 12) The threshold
is a 30 decibel increase over the current GPS AJ capability. The
objective is more than a 30 decibel increase over the current AJ
capability, as recommended by the Defense Science Board.

4.7.2.6 [Spoofing Protection]{.underline}. Ensure reliable information
transmission to the system for proper control and use including
protection against spoofing or injection of false or unauthorized
information*.* Military PVT systems must be capable of operating in and
through a spoofed environment (threshold). Operate is defined as the
ability to detect, acquire, maintain, and reacquire the PVT signal in a
spoofed environment[^4] to allow systems to meet combat mission
requirements. (Ref 12)

4.7.2.7 [Exploitation]{.underline}. PVT, in concert with other
prevention systems, shall be capable of countering or preventing
globally and regionally, the exploitation of the PVT signal. (REF 12)
This capability must allow countering exploitation without forcing the
US to jam its own PVT signals.

4.7.2.8 [Anti-Spoof Signal Acquisition]{.underline}. Ensure that
authorized users have the means to acquire the anti-spoof signal and do
not have to rely on unprotected signals for initial acquisition.

4.7.2.9 [Anti-Spoof Signal Tracking]{.underline}. Ensure that authorized
users have the means to track the anti-spoof signal in an intentional
jamming environment, either hostile or friendly.

4.7.2.10 [System Accuracy]{.underline}. The system must have the
capability to control the level of system accuracy available to hostile
users. All command and telemetry links must be secure.

4.7.2.11 [Capability to Operate Under Prevention]{.underline}. PVT shall
be capable of detecting, acquiring, maintaining, reacquiring or
providing PVT information to platforms during periods of US prevention
of the adversarial use of PVT. (REF 12)

4.7.2.12 [Encryption]{.underline}. Encryption schemes and key handling
for users shall minimize the probability of compromise (reduce
handling), reduce the requirement for communications security control of
PVT devices, and provide rapid suppression of cryptological variables
should compromise occur. (REF 12)

4.7.2.13 [Algorithm Access]{.underline}. System security must be
adequate to protect access to system algorithms and any classified data.
(REF 12)

4.7.2.14 [Satellite Operations]{.underline}. The PVT system shall enable
authorized satellite-based users to avoid performance degradation of PVT
information in a stressed environment. All satellite-based users
supporting national security missions shall be equipped to operate in a
stressed environment.

### Rationale

4.7.3.1 [Increased Dependence]{.underline}. The multiplication of GPS
applications within the US Armed Forces dramatically increases both the
importance of PVT systems for military activities and the dependence of
these organizations on such systems. This dependence increases the need
for effective anti-jamming and anti-spoofing capabilities. (Ref 46)

4.7.3.2 [Adversarial Use]{.underline}. The unencrypted GPS coarse
acquisition (C/A) code still provides adversaries with an accuracy of
100 meters, which would still be more than adequate to deliver chemical,
biological, or even explosive weapons, if creating terror in a city is
the enemy's objective. Further, any enemy encountered is not likely to
share the US military's interest in limiting collateral damage. (Ref 46)
The PVT system must take the necessary steps to provide the level of
security for operations in any environment at any time. There must an
ability to prevent access to all aspects of the PVT system to hostile
elements. The only countermeasure currently available to US Forces is
jamming its own signal. This technique denies US use and violates the
requirements of the PDD to allow friendly use of the PVT system. From a
safety perspective, the system must avoid vulnerability to interference.
(REF 23)

4.7.3.3 [Spoofing and Jam Resistance]{.underline}. Systems should be as
survivable and endurable as the forces and weapon systems they support
including hostile attack, EMP, and natural phenomena. Multiple studies
have identified current GPS AJ capabilities as inadequate. Future
jamming environments will likely be more severe. Increasing PVT system
AJ capabilities by 30 decibels or more would force an adversary to use a
jammer that had enough output power it would be easy to locate and
target the jammer.

Reference:

a\. CJCSI 6130.01, Enclosures B and D

b\. GOR attach 1, para 1c.(2)(b) (REF 12)

4.7.3.4 [System Security]{.underline}. Required to protect the PVT
signal availability, anti-spoof, and accuracy calculation algorithms.

Reference: PMD 4075(25)/PE35164F/35165F, 8 May 87. (REF 12)

## CONTINUITY OF SERVICE

### Definitions

4.8.1.1 [Continuity of Service]{.underline}. Continuity of service (COS)
is the ability of a PVT system to provide required service over a
specified period of time without interruption. The level of continuity
is expressed in terms of the probability of not losing the radiated
signals.

Continuity of Service is measured in terms of: (1) ranging signal
failure frequency; (2) failure duration; (3) failure magnitude and
behavior; (4) distribution of user population around the globe; (5)
probability that the failed satellite is used in the position solution;
and (6) effect that the failure has on the position solution, given the
failed satellite\'s contribution to solution geometry and the
receiver\'s response to the failure condition.

4.8.1.2 [Continuity of Navigation]{.underline}. Continuity of navigation
is the ability of the system to provide an accurate signal over a
specified period of time without loss of accuracy. The level of
continuity is expressed in terms of the probability of not losing the
accuracy of the radiated signal. Continuity of navigation is measured
only in terms of the frequency of failure of signal accuracy. (See
4.6.1.3 Service Reliability.)

4.8.1.3 [Continuity of Fault Detection]{.underline}. Continuity of fault
detection is the ability of the system to provide a required level of
integrity of a signal over a specified period of time without loss of
integrity. The level of continuity is expressed in terms of probability
of not losing the required level of integrity of the radiated signal.
Continuity of fault detection is measured only in terms of the frequency
of failure of signal integrity.

4.8.1.4 [Difference Between Continuity of Navigation, Continuity of
Fault Detection, and Continuity of Service]{.underline}. Continuity of
Navigation (also known as Continuity of Accuracy under RNP) and
Continuity of Fault Detection (also known as Continuity of Integrity
under RNP) are subsets of Continuity of Service. Continuity of Service
indicates all operations will have continuity, reflecting the frequency
with which operations may fail and the amount of time the operations
will be down. Continuity of Navigation and Continuity of Fault Detection
are concerned only with the frequency that accuracy and integrity will
fail, but not with the duration.

### Requirements

The most stringent threshold values for continuity of service
requirements are in Table 4-11.

Table 4-11. Threshold Requirements for Continuity of Service

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            |                        |                        |
+--------------------+------------------------+------------------------+
| Air                | **10^-8^** **per       | **Ref 4**              |
|                    | hour**                 |                        |
|                    |                        | FAA                    |
|                    | 1-6x10^-6^ (any 15 sec |                        |
|                    | priod)                 |                        |
+--------------------+------------------------+------------------------+
| Space              |                        |                        |
+--------------------+------------------------+------------------------+

Table 4-12 provides the most stringent objective values for the
requirements of each of the different mediums.

Table 4-12. Objective Requirements for Continuity of Service

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         |                        |                        |
+--------------------+------------------------+------------------------+
| Surface            |                        |                        |
+--------------------+------------------------+------------------------+
| Air                | **10^-8^** **per       | **Ref 4**              |
|                    | hour**                 |                        |
|                    |                        | FAA                    |
|                    | 1-6x10^-6^ (any 15 sec |                        |
|                    | priod)                 |                        |
+--------------------+------------------------+------------------------+
| Space              |                        |                        |
+--------------------+------------------------+------------------------+

The discussions that follow provide the basis for designating the most
stringent values in the previous tables. A complete listing of the
requirements, both military and civil, for continuity of service are in
Appendix A.

The PVT design must identify: (1) statistical departures from nominal
system ranging accuracy; (2) a navigation message structure or content
violation which impacts the receiver\'s navigation message processing
capabilities; and (3) a ranging signal RF characteristic, navigation
message structure or navigation message contents violation that impacts
the receiver\'s minimum ranging signal reception or processing
capabilities.

4.8.2 1 [Enroute through Non-Precision Approach.]{.underline} The
probability of loss of COS for the navigation system, for outages
affecting multiple aircraft, shall be no more than 10 ^-8^/ hour for
every location and time.

4.8.2 2 [Precision Approach]{.underline}. Aircraft UE, in conjunction
with augmentations, shall provide a probability of the loss of COS of
5.5 X 10 ^-5^ per approach. For precision approaches to ships, COS for
the last 12 seconds of the approach shall equal the HMI rate.

4.8.2.3 [Satellite Operations]{.underline}. The future PVT system shall
provide continuous position, precise time, and attitude determination
support to satellite-based users 24 hours per day every day. This
continuity of service shall include the ability of satellite-based users
to continue operations during periods of interference on any single data
link used for transfer of position, time, and attitude determination
information by utilization of an alternate data link for receiving the
information.

### Rationale

Users must have confidence the PVT system will operate properly during
the time they need it. They must also be confident the system will alert
them if a problem develops during use.

## AFFORDABILITY

### Definition

PVT system operations can be viewed as an overhead cost in that it
provides a capability to a user to perform a mission. As with any
overhead cost, it behooves the system owner/operator to minimize costs
where ever possible.

Cost can include development and procurement, but there are potential
savings in PVT system operations in the day to day operating expenses.
These are typically (but not necessarily limited to) manpower, training,
facilities, hardware/software maintenance, and leased assets.

### Requirements

[Economic Performance]{.underline}. The PVT system must provide an
economic performance and benefit enhancement. Budgetary pressures,
coupled with the US commitment to provide PVT signals indefinitely,
force the need for an affordable solution. With the wide impact on day
to day life that the PVT system has, there is a need for the PVT system
to provide capabilities at an affordable level for the owners and
operators as well as for all users. The PVT system must be
cost-effective and at the same time must provide service of useful
quality to all classes of users. Any changes to the PVT system shall be
assessed for impact on the affordability of user equipment. Required UE
modifications must be held to a minimum.

### Rationale. 

Accurate radionavigation systems can contribute to better productivity
and decreased delay in transit. The need to conserve energy resources
and to reduce costs provides powerful incentives for increased
transportation efficiency, some of which can come from better navigation
systems. With the current budgetary constraints, costs have become a key
driver in fielding or modifying any system. This will not likely change
in the near future. Commercial endeavors require profit in a finite
amount of time and with the current rate of technological evolution,
this time period is reducing.

Multi-user (outside the DoD) systems are uncommon for the DoD. Seeking
economic benefits from a system are unusual in DoD planning. Yet,
potential PVT system economic benefits (outside the DoD) are
substantial. Making these benefits available to all users as soon as
possible is important. Development and deployment schedules must
consider benefits that can be achieved by early deployment. This means
the selected architecture should be available in a reasonable amount of
time, without having to stretch out procurement due to high cost and
high risk. (REF 23)

## COVERAGE

### Definition

The coverage provided by a radionavigation system is that surface area
or space volume in which the signals are adequate to permit the users to
determine position, velocity, and timing to a specified level of
accuracy. Coverage is influenced by system geometry, signal power
levels, receiver sensitivity, atmospheric noise conditions, and other
factors that affect signal availability.

### Requirements

The most stringent threshold values for coverage requirements are in
Table 4-13. A complete listing of the requirements, both military and
civil, for coverage are in Appendix A.

Table 4-13. Threshold Requirements for Coverage

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         | **TBD**                | Ref 44                 |
|                    |                        |                        |
|                    | Worldwide through all  |                        |
|                    | operating environments |                        |
+--------------------+------------------------+------------------------+
| Surface            | **Worldwide through    | Ref 12                 |
|                    | all operating          |                        |
|                    | environments**         | Ref 44                 |
|                    |                        |                        |
|                    | Worldwide through all  |                        |
|                    | operating environments |                        |
+--------------------+------------------------+------------------------+
| Air                | **Worldwide through    | Ref 12                 |
|                    | all operating          |                        |
|                    | environments**         | FAA                    |
|                    |                        |                        |
|                    | Global (per            |                        |
|                    | availability & COS     |                        |
|                    | requirements)          |                        |
+--------------------+------------------------+------------------------+
| Space              | **Global to            | **SATOPS ADT**         |
|                    | geostationary          |                        |
|                    | altitude**             | SATOPS ADT             |
|                    |                        |                        |
|                    | Global to              |                        |
|                    | geostationary altitude |                        |
+--------------------+------------------------+------------------------+

\* Worldwide includes 90 degrees south to 90 degrees north latitude and
0 degrees to 359 degrees longitude.

Table 4-14. Objective Requirements for Coverage

+--------------------+------------------------+------------------------+
|                    |                        | Source                 |
+--------------------+------------------------+------------------------+
| Subsurface         | **Worldwide\* through  | Ref 12                 |
|                    | all operating          |                        |
|                    | environments**         | Ref 44                 |
|                    |                        |                        |
|                    | Worldwide through all  |                        |
|                    | operating environments |                        |
+--------------------+------------------------+------------------------+
| Surface            | **Worldwide through    | Ref 12                 |
|                    | all operating          |                        |
|                    | environments**         | Ref 44                 |
|                    |                        |                        |
|                    | Worldwide through all  |                        |
|                    | operating environments |                        |
+--------------------+------------------------+------------------------+
| Air                | **Worldwide through    | Ref 12                 |
|                    | all operating          |                        |
|                    | environments**         | FAA                    |
|                    |                        |                        |
|                    | Global (per            |                        |
|                    | availability & COS     |                        |
|                    | requirements)          |                        |
+--------------------+------------------------+------------------------+
| Space              | **Global to twice      | **SATOPS ADT**         |
|                    | geostationary          |                        |
|                    | altitude**             | SATOPS ADT             |
|                    |                        |                        |
|                    | Global to twice        |                        |
|                    | geostationary altitude |                        |
+--------------------+------------------------+------------------------+

\* Worldwide includes 90 degrees south to 90 degrees north latitude and
0 degrees to 359 degrees longitude.

4.10.2.1 [Canopy Penetration]{.underline}. The PVT system should provide
improved coverage in forest and canyon areas, especially in northern
latitudes. The system should also support the reception of signals
inside buildings.

4.10.2.2 [Satellite Operations]{.underline}. The PVT system should
provide coverage to support position and velocity information to all
satellites below 10,000 km altitude. The PVT system shall support
satellite-based users in performing autonomous positioning, determining
satellite attitude, and marking precise time, 24 hours per day, for
satellites in any LEO, out to Highly Elliptical Orbit (HEO), where the
apogee of a HEO does not exceed twice the GEO apogee.

### Rationale. 

Specific constellation design objectives are: (1) provide continuous
global coverage with specified geometry and mask angle constraints, (2)
minimize coverage sensitivity to expected satellite orbital drift
characteristics, and (3) mitigate the effects on service availability of
removing any one satellite from service.

Several factors affect GPS constellation coverage. These factors must be
taken into consideration in the constellation design. The factors are:
(1) The difference between the planned orbit and the orbit actually
achieved during the launch and orbit insertion process, (2) orbit
variation dynamics, and (3) frequency and efficiency of satellite
stationkeeping maneuvers.

The information provided by the PVT system is intended to support
terrestrial users worldwide, as well as space users from LEO to
Geostationary /Geosynchronous Earth Orbit. There is growing dependence
on current PVT systems in all facets of everyday life. PVT signals are
being used in steep canyon environments, urban and rural, in such tasks
as tracking vehicle, individual and wildlife movement. People are
discovering new uses for the GPS signal as shown in Table 1-2.

Military forces must be prepared to project global presence. To enhance
the role of all military forces in exerting presence, military forces
must incorporate technological innovations into all operations. By
providing worldwide coverage, PVT will enhance the ability to monitor
and assess global conditions rapidly and efficiently. PVT will allow
commanders improved transport technology to enable rapid and accurate
deployment of resources worldwide. Weapon system technology enhancements
are dependent upon PVT to provide the coverage necessary for accurate
weapons delivery.

a\. CJCSI 6130.01, Enclosure B, paragraph 1.a.

b\. White Paper, *Global Presence*, Sheila E. Widnall, Secretary of the
Air Force, General Ronald R. Fogelman, Chief of Staff, U.S. Air Force
(REF 12)

## SUPPORTABILITY 

### Definition

This characteristic indicates the degree to which all operations and
logistics elements combine to satisfy system control and dependability
requirements. It incorporates such diverse elements as reliability,
maintainability, manpower and training, supply support, packaging,
handling, transport, support equipment, technical data, and facilities.
It also includes control of the PVT system.

### Requirements

4.11.2.1 [Standard Logistics Infrastructure]{.underline}. This PVT
system, to include the user equipment, will make maximum use of standard
Agency-specific logistics infrastructure, minimize demands on personnel,
and the environment, and be readily adaptable, so that if needed, it can
be modified for use with any follow-on systems. Supportability ensures
the system will be available, in-place, and durable.

4.11.2.2 [Reliability & Maintainability]{.underline}. The reliability of
worldwide PVT system components shall be determined as a function of
overall cost and performance requirements. Support of PVT components
should be simplified and compatible with the existing Agency supply
system. Emphasis must be placed on improving maintenance efficiency,
including integrated diagnostics, and simple remove and replace
maintenance and upgrade actions."

4.11.2.2.1 [Space and Control]{.underline}. The space and control
segment should emphasize robust design, commonality, highly reliable
components and integrated diagnostics. The space segment equipment
should be designed to survive potential operational and launch rigors.
The control segment equipment should be designed for simple remove and
replace maintenance actions and to survive potential operational rigors
and minimize transport requirements. The control segment should be
capable of providing operational control and monitoring performance of
the PVT system 100 per cent of the time.

4.11.2.2.2 [User Equipment]{.underline}. The UE segment should emphasize
robust design, commonality, highly reliable components, integrated
diagnostics, and simple remove and replace maintenance actions. UE
should be designed to survive potential operational and handling rigors
and minimize transport requirements. It is also expected to have
predicted reliabilities orders of magnitudes higher than its
predecessors. The UE reliability thresholds and mature specification
requirements should be increased to account for the significantly higher
predicted reliabilities.

4.11.2.3 [Training and Operation]{.underline}. Training will be
incorporated into training programs as established by the cognizant
agency or department. Instruction shall produce the required operational
skills for normal and anomalous/emergency operations.

4.11.2.4 [Maintenance]{.underline}. Maintenance of the PVT system shall
be established by the owners/operators of components of the PVT system.
The owners shall be responsible for providing the requisite maintenance
training needed for operations personnel to maintain the component.

4.11.2.5 [System Safety]{.underline}. System safety programs will be
conducted in accordance with appropriate service/agency directives. The
program will ensure orbital safety concerns are addressed in systems
engineering. For the ground segment, Federal Occupational Safety and
Health Administration regulations and appropriate industry standards
will be implemented. (REF 12)

4.11.2.6 [Simulators]{.underline}. Simulators shall be provided to train
operations and maintenance crew personnel. (REF 12)

### Rationale.

Supportability is important to PVT systems and its implementation varies
by PVT component. Individual supportability requirements for PVT system
components will be identified in component ORDs.

4.11.3.1 [Standard Logistics Infrastructure]{.underline}. Conformance
with the practices established by standard logistics infrastructures
ensures that new systems and equipment acquired will exhibit
cost-effective, supportable design with emphasis on optimizing logistics
resources.

4.11.3.2 [Training and Operation]{.underline}. Training of personnel on
the operations of the PVT system is essential to prevent reduction in
system availability and reliability.

4.11.3.3 [Maintenance]{.underline}. With the increased dependence on PVT
systems, especially GPS, maintenance concepts are needed to ensure that
the PVT systems operate at the peak of reliability and availability.

4.11.3.4 [System Safety]{.underline}. Safety needs to be addressed in
all phases of the PVT system to ensure that the system performs to the
levels required.

4.11.3.5 [Simulation Capability]{.underline}. High fidelity simulation
is required to support training, planning, testing, and war-gaming to
prevent operational errors and to support engineering and analysis. (REF
12)

## SURVIVABILITY

### Definition

Survivability is defined as the capability to avoid or withstand the
impact of a hostile environment (man-made or natural) without suffering
an abortive impairment of the ability to accomplish the most critical
mission requirements. (REF DoD 5000.3)

### Requirements

In general, the PVT system must be as survivable as the missions and
forces it supports.

4.12.2.1 [Natural Environment Protection]{.underline}. Ensure that
space-based systems, specifically space vehicles and control stations,
are survivable against the natural environment of near-earth space
(ionospheric scintillation, natural radiation belts, radiation events
due to solar flares, and galactic cosmic rays) and against man-made
environments. The space-based system must be capable of operating
without degradation in potentially hostile environments (enhanced
radiation belts due to detonation of nuclear weapons above the
atmosphere, directed energy weapons from the ground, etc.).

4.12.2.2 [Wartime Requirements]{.underline}. The mission of PVT is to
support user requirements through all levels of conflict, consistent
with the forces supported. (REF 12)

4.12.2.3 [Biological and Chemical Survivability]{.underline}. The PVT
design will meet or exceed biological and chemical survivability
requirements consistent with all levels of conflict.

4.12.2.4 [Continuous Control Capability]{.underline}. The PVT system
must have a 24-hour control capability.

4.12.2.5 [Satellite Operations]{.underline}. The PVT system shall be
designed such that satellite-based users supporting national security
missions shall be able to complete their mission in the presence of
intentional interference, spoofing, or temporary loss of PVT system
ground control capability. In addition, the PVT system shall be designed
such that all satellite-based users shall be capable of surviving
unintentional or natural interference.

### Rationale. 

The survivability of certain PVT systems is vital to US national
interests. It is necessary to identify and protect tactical and
strategic minimum essential capabilities that must be relied upon even
in the face of the most capable adversaries. The US must preclude the
ability of an adversary to incapacitate our PVT capabilities.

## INTEROPERABILITY

### Definition

Interoperability is defined as the ability of the PVT system to provide
GPS Standard Positioning Service in accordance with the PDD; to be
compatible with legacy UE; and to provide seamless PVT information,
referenced to a common grid, via the system of systems.

### Requirements

4.13.2.1 [Civil/Military Interoperability]{.underline}. The basic
capabilities to permit common use and common operational procedures by
civil and military users should be provided. The highest degree of
commonality and system utility between military and civil users is
sought through early consideration of mutual requirements. Civil and
military PVT equipment should be compatible to the extent feasible. In
addition, the number of transmission formats should be kept to a minimum
in meeting diverse civil requirements. There is merit in this approach
since many applications are the same (or similar) and coordinated
purchases could result in more capable UE, at lower cost, for both
groups.

4.13.2.2 [International Acceptance]{.underline}. Navigation services and
systems should be technically and politically acceptable to diverse
groups, including NATO and other allies, ICAO, International
Telecommunications Union, and International Maritime Organization (IMO).

4.13.2.3 [Data Referenced to a Common Grid]{.underline}. In order to
establish a common grid for reference, the navigation, position, and
velocity information must be referenced to a commonly used geolocation
standard. Data is currently referenced to the World Geodetic Survey 1984
(WGS-84). Data for future systems must be referenced to an agreed-upon
standard utilized or established by the NIMA and updated as needed. The
system must provide a signal that can be translated to any common datum.

4.13.2.4 [Operations]{.underline} . All changes to the PNT system that
affect the existing GPS will be made in a manner such that the structure
and performance of the existing system signals will not change. New PVT
systems must support backward compatibility and work with current UE
(REF 12)for at least the near and mid term. For the far term, new
signals/signal structures may require new UE. If so, a transition period
must be established over such a length of time as to allow affordable
replacement of UE. Protection requirements may require acquisition of
new UE, if the mission requires protected services. If the mission does
not require protected services, existing UE must continue to provide
PVT.

4.13.2.5 [Integration with Service/Agency Programs]{.underline}.
Integration into Service/Agency-specific command, control,
communications, and intelligence programs will be dependent upon
agency/service needs. Sufficient technical system information must be
made available in order for users to integrate the PVT signals into
their applications.(REF 12)

4.13.2.6 [Integrated Displays]{.underline}. Close coupling of the PVT
system signal will be required with geospatial information for
navigation. The PVT system should provide information at the level of
detail that users need. Automatic updates of the information should be
available so that the user will have current accurate information.
Military UE must support standard military and commercial interfaces to
provide PVT information for the given application.

4.13.2.7 [Common Frequency.]{.underline} Primary and augmentation PVT
systems elements should operate on the same (or compatible) frequencies,
with the intent of reducing the size, quantity and cost of receivers and
additional equipment needed for PVT needs.

[Rationale]{.underline}: Many applications currently require moving
additional equipment to remote locations to meet the accuracy
requirements of the operation. This necessity can be reduced by a fully
integrated PVT system operating on compatible standards.

4.13.2.8 [Regional and Local Systems]{.underline}. Future global PVT
systems must provide a practical interface to regional and local systems
such as WAAS, LAAS, and JPALS.

4.13.2.9 [Satellite Operations]{.underline}. Due to the inaccessibility
of spaceborne receivers on unmanned spacecraft and the timelines
associated with developing new satellite-based user equipment, any
changes in format or performance characteristics of the PNT system must
be evaluated for impacts on the installed and planned set of
satellite-based users.

### Rationale

In the future, electronic displays will replace maps for use in
navigation. The user will require the latest, most accurate information
available.

L1 C/A backward compatibility is extremely important in order to
continue service to the likely millions of low cost product users.

The goals of interoperability and cost minimization of user equipment
influence the search for an international consensus on a selection of
radionavigation systems. For civil aviation, the ICAO establishes
standards for internationally used radionavigation systems. For the
international maritime community, a similar role is played by the IMO.
Traditionally, IMO has been less stringent in establishing
radionavigation requirements for the maritime community than ICAO has
been for the aviation community. The IALA also develops international
radionavigation guidelines. IMO is reviewing existing and proposed
radionavigation systems to identify a system or systems that could meet
the requirements of, and be acceptable to, members of the international
maritime community.

## RECOMMENDED KEY PERFORMANCE PARAMETERS

The following required system characteristics are further delineated as
KPPs. Actual, affordable values associated with the KPPs will be
determined by SMC through the efforts associated with the Acquisition
Master Plan. Since each KPP encompasses multiple requirements, the
critical item is listed for each KPP, when required.

4.14.1 Position Accuracy

Position accuracy requirements are driven by many different
applications. Many users require substantially better position accuracy
than can be provided by the current GPS SPS or PPS. Position accuracy is
critical to precision approach, close air support, mine laying,
precision guided munitions delivery, and delivery of conventional high
velocity penetrator weapons for attack of hard and deeply buried
targets. Enhanced accuracy will improve the usefulness of any PVT system
thus expanding applications and potential economic benefit. (REF 23)
Failure to provide a PVT capability that meets position accuracy
requirements would nullify the policies of the PDD.

4.14.2 Velocity Accuracy

Accurate velocity indication is critical to multiple users, both
military and civil.

4.14.3 Timing Accuracy

Precise time is essential to users who must time-synchronize other
systems. Today, GPS has evolved into the primary system by which the
USNO maintained reference time is distributed for most DoD systems. (REF
12It is anticipated that, in the future, even more users will rely on
these PVT systems for establishing precise time.

4.14.4 Integrity

PVT systems must positively notify operators when a system fails or is
emitting out of tolerance signals. Military, commercial, scientific and
other mission users rely upon accurate, usable PVT information for
safety of life and mission accomplishment. Operators of radionavigation
aids are required by law to provide timely warning to users when the
system will not be available for use.

Reference: Title 14, USC 81-83 . (REF 12)

4.14.5 Availability

Position, timing, and velocity accuracy provide three-dimensional
predictable, relative, and repeatable information to authorized users.
Accuracy relies on Availability. Without a high Availability, PVT
accuracy for users could suffer. Integrity is essential to provide
adequate safety for aviation and other uses.

4.14.6 Security

The PVT system must take the necessary steps to provide the level of
security for operations in any environment at any time.

4.14.7 Continuity of Service

Continuity of Service is mandatory. The PVT system must operate properly
when needed.

4.14.8 Affordability

Cost must be considered equally with other system characteristics.

## TRANSITION ISSUES

### Continuity of Operations

This issue relates to issues/requirements that must be addressed to
support operations while new and legacy PVT systems are operational.

User concerns with having to rely on one PVT system must be balanced
with the need to consolidate and reduce the number of systems. The
constantly changing radionavigation user profile and rapid advancements
in systems technology require that the PVT concept remain as dynamic as
the issues addressed.

### Backward Compatibility

Modification and transition of systems should occur in an orderly manner
to accommodate technical improvements. Only those systems that serve a
significant number of users and provide the economic benefits in excess
of costs should continue in operation. In some cases duplicate systems
will have to be maintained for safety reasons and to allow adequate time
for the transition to newer more accurate systems; however, older
systems must be evaluated to determine whether or not their level of use
is cost-effective.

### Force Structure

Manpower and facility requirements based upon engineering, operational,
and maintenance considerations include: (1) equipment dimensions, (2)
space availability, (3) system safety, (4) accessibility, (5) worldwide
coverage, (6) physical security requirements, (7) the need for
continuous around-the-clock operations, and (8) multi-service,
multi-national agreements.

diverse PVT requirements, including civilian ustrates soms various Air
Force prol Accessams falprograms and Avionics Modernization, will have
some solutions that are outside of the PVT system. Likewise, the
Navigation and Safety Equipment Master Plan addresses cockpit voice
recorders, as well as installation of GPS receivers all DoD
passenger-carrying aircraft.

**APPENDIX A**

**POSITION, VELOCITY, AND TIME REQUIREMENTS**

<table style="width:100%;">
<colgroup>
<col style="width: 23%" />
<col style="width: 8%" />
<col style="width: 2%" />
<col style="width: 5%" />
<col style="width: 5%" />
<col style="width: 2%" />
<col style="width: 8%" />
<col style="width: 0%" />
<col style="width: 8%" />
<col style="width: 2%" />
<col style="width: 5%" />
<col style="width: 5%" />
<col style="width: 2%" />
<col style="width: 8%" />
<col style="width: 0%" />
<col style="width: 7%" />
</colgroup>
<thead>
<tr class="header">
<th colspan="16"><strong>POSITION ACCURACY - MILITARY</strong></th>
</tr>
<tr class="odd">
<th><strong>OPERATIONAL ENVIRONMENT/ MISSION</strong></th>
<th colspan="13"><strong>REQUIREMENTS</strong></th>
<th colspan="2"><strong>SOURCE</strong></th>
</tr>
<tr class="header">
<th></th>
<th colspan="6"><strong>THRESHOLD</strong></th>
<th colspan="7"><strong>OBJECTIVE</strong></th>
<th colspan="2"></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td>I. EARTH AND ATMOSPHERE</td>
<td colspan="6"></td>
<td colspan="7"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IA LAND</td>
<td colspan="6"></td>
<td colspan="7"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IA1 SURFACE</td>
<td colspan="6"></td>
<td colspan="7"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IA1e ARMY LAND</td>
<td><strong>Horizontal Position (m-CEP)</strong></td>
<td colspan="2"><strong>Vertical Position (m-LEP)</strong></td>
<td colspan="2"><strong>Direction (Mils-LEP)</strong></td>
<td><strong>Response Time (Minutes - 1 Sigma)</strong></td>
<td colspan="2"><strong>Horizontal Position (m-CEP)</strong></td>
<td colspan="2"><strong>Vertical Position (m-LEP)</strong></td>
<td colspan="2"><strong>Direction (Mils-LEP)</strong></td>
<td><strong>Response Time (Minutes - 1 Sigma)</strong></td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>IA1e(1) CHEMICAL</td>
<td><p>10.5 m</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>(2) ENGINEER</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>(2)(a) MINE NEUTRAL</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>(2)(b) MINE DISPENSING</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>(2)(c) GAP CROSSING</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>IA1e(3) FIELD ARTILLERY</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>(3)(a) MLRS</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>(3)(b) HOWITZER (TOWED)</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>(3)(c) HOWITZER (SELF-PROPELLED)</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>(3)(d) MORTARS</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>(3)(e) FIST-V</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>(3)(f) FORWARD OBSERVER</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>(3)(g) ARTILLERY RADAR</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>(3)(h) MORTAR LOCATING FIREFINDER RADAR</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td><strong>Horizontal Position (m-CEP)</strong></td>
<td colspan="2"><strong>Vertical Position (m-LEP)</strong></td>
<td colspan="2"><strong>Direction (Mils-LEP)</strong></td>
<td><strong>Response Time (Minutes - 1 Sigma)</strong></td>
<td colspan="2"><strong>Horizontal Position (m-CEP)</strong></td>
<td colspan="2"><strong>Vertical Position (m-LEP)</strong></td>
<td colspan="2"><strong>Direction (Mils-LEP)</strong></td>
<td><strong>Response Time (Minutes - 1 Sigma)</strong></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IA1e(4) INFANTRY</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>IA1e(5) MISSILE MUNITIONS</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>IA1e(6) SIGNAL</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>IA1e(7) TRANSPORATION (WHEELED VEHICLE)</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>IA1e(8) SOLDIER SUPPORT</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>IA1e(9) ARMOR</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>IA1e(10) MILITARY POLICE</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>IA1e(11) SPECIAL OPS FORCES</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>IA1e(12) INTELLIGENCE ELECTRONIC WARFARE</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>IA1e(13) QUARTERMASTER</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>IA1e(14) ORDINANCE</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>IA1e(15) AIR DEFENSE ARTILLERY</td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IA1e(15)(a) PATRIOT</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="even">
<td>IA1e(16)(b) HAWK</td>
<td><p>10.5</p>
<p>(5 m)</p></td>
<td colspan="2"><p>8.7 m</p>
<p>(3 m)</p></td>
<td colspan="2"><p>1.16 mils</p>
<p>(0.4 mils)</p></td>
<td>100 nsec</td>
<td colspan="2"><p>2.1 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>2.9 m</p>
<p>(1 m)</p></td>
<td colspan="2"><p>.29 mils</p>
<p>(0.10 mils)</p></td>
<td>10 nsec</td>
<td colspan="2">REF 35</td>
</tr>
<tr class="odd">
<td>IA2 SUBTERRANEAN</td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IB MARINE</td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IB1 NAVAL</td>
<td colspan="2"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-SEP)</strong></p></td>
<td colspan="2"><strong>Heading (Degrees-LEP)</strong></td>
<td colspan="3"><p><strong>Altitude/Depth</strong></p>
<p><strong>(m-LEP)</strong></p></td>
<td colspan="2"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-SEP)</strong></p></td>
<td colspan="2"><strong>Heading (Degrees-LEP)</strong></td>
<td colspan="3"><p><strong>Altitude/Depth</strong></p>
<p><strong>(m-LEP)</strong></p></td>
<td></td>
</tr>
<tr class="even">
<td>IB1a ENROUTE NAVIGATION</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td>IB1a(1) PILOTAGE WATERS</td>
<td colspan="2">72</td>
<td colspan="2">0.8</td>
<td colspan="3">1% Depth</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td></td>
<td colspan="2"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-SEP)</strong></p></td>
<td colspan="2"><strong>Heading (Degrees-LEP)</strong></td>
<td colspan="3"><p><strong>Altitude/Depth</strong></p>
<p><strong>(m-LEP)</strong></p></td>
<td colspan="2"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-SEP)</strong></p></td>
<td colspan="2"><strong>Heading (Degrees-LEP)</strong></td>
<td colspan="3"><p><strong>Altitude/Depth</strong></p>
<p><strong>(m-LEP)</strong></p></td>
<td></td>
</tr>
<tr class="odd">
<td>(2) COASTAL WATERS</td>
<td colspan="2">72</td>
<td colspan="2">0.8</td>
<td colspan="3">1% Depth</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>(3) INLAND WATERS</td>
<td colspan="2">25</td>
<td colspan="2">0.8</td>
<td colspan="3">1% Depth</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="odd">
<td>(4) OPEN WATERS</td>
<td colspan="2">2,400</td>
<td colspan="2">0.8</td>
<td colspan="3">5% Depth</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>(5) RENDEVOUS</td>
<td colspan="2">380</td>
<td colspan="2">0.8</td>
<td colspan="3">5% Depth</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="odd">
<td>(6) HARBOR NAVIGATION</td>
<td colspan="2">8</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>(7) DYNAMIC POSITIONING</td>
<td colspan="2">TBS</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td>(8) LAW ENFORCEMENT</td>
<td colspan="2">TBS</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td>(9) ICE BREAKING</td>
<td colspan="2">TBS</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td>(10) SEARCH AND RESCUE</td>
<td colspan="2">TBS</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td>IB1b MINE WARFARE</td>
<td colspan="2">&lt;2 M SEP</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 4</td>
</tr>
<tr class="odd">
<td>IB1b(1) NAV IN SWEPT CHANNEL</td>
<td colspan="2">16</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>(2) DEFENSIVE MINING</td>
<td colspan="2">16</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="odd">
<td>(3) OFFENSIVE MINING</td>
<td colspan="2">16</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>(4) ANTIMINE COUNTERMEASURES</td>
<td colspan="2">&lt;2 M SEP</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 4</td>
</tr>
<tr class="odd">
<td>(5) GEODETIC REFERENCE GUIDE (WGS-84)</td>
<td colspan="2">128</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>IB1c SPECIAL WARFARE</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td>IB1c(1) PARADROP</td>
<td colspan="2">20</td>
<td colspan="2">1</td>
<td colspan="3">50.0</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>(2) SMALL CRAFT</td>
<td colspan="2">50</td>
<td colspan="2">1</td>
<td colspan="3">50.0</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="odd">
<td>(3) COMBAT SWIMMING</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td>IB1c(3)(a) ENROUTE</td>
<td colspan="2">3</td>
<td colspan="2">0.5</td>
<td colspan="3">0.3</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="odd">
<td>(b) RENDEVOUS</td>
<td colspan="2">1</td>
<td colspan="2">0.5</td>
<td colspan="3">0.3</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>IB1c(4) LAND WARFARE</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td>IB1c(4)(a) ENROUTE</td>
<td colspan="2">3</td>
<td colspan="2">1</td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>IB1c(4)(b) RENDEVOUS</td>
<td colspan="2">1</td>
<td colspan="2">1</td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="odd">
<td>IB1c(5) INSERTION</td>
<td colspan="2">1</td>
<td colspan="2">1</td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="even">
<td>IB1c(6) EXTRACTION</td>
<td colspan="2">1</td>
<td colspan="2">1</td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="odd">
<td>IB1d TASK GROUP OPERATIONS</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td>IB1d(1) MANEUVERING IN CLOSE COMPANY</td>
<td colspan="2">72 (Relative Position)</td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td>REF 39</td>
</tr>
<tr class="odd">
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td>IB1e AMPHIBIOUS WARFARE</td>
<td><p><strong>Horizontal Position</strong></p>
<p><strong>(m-CEP)</strong></p></td>
<td colspan="2"><strong>Heading (Km/Hr-LEP)</strong></td>
<td colspan="2"><p><strong>Altitude</strong></p>
<p><strong>Roll/Pitch</strong></p></td>
<td><strong>Heave (cm-LEP)</strong></td>
<td colspan="2"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-CEP)</strong></p></td>
<td colspan="2"><strong>Heading (Km/Hr-LEP)</strong></td>
<td colspan="2"><p><strong>Altitude</strong></p>
<p><strong>Roll/Pitch</strong></p></td>
<td><strong>Heave (cm-LEP)</strong></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IB1e(1) BEACH SURVEYS</td>
<td>185</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>(2) LANDING CRAFT</td>
<td>50</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>(3) ARTILLERY</td>
<td>&lt;6</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>(4) RECONNAISSANCE</td>
<td>&lt;5</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IB1f HYDROGRAPHIC/ OCEANOGRAPHIC SURVEYS</td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IB1f(1) HYDROGRAPHIC SURVEYS</td>
<td>&lt;5 drms</td>
<td colspan="2">0.8</td>
<td colspan="2">72</td>
<td>5</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>(2) OCEAN SURVEYS</td>
<td>90 drms</td>
<td colspan="2">0.03</td>
<td colspan="2">105</td>
<td>30</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>(3) OCEANOGRAPHIC SURVEYS</td>
<td>100 drms</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IB1g GEOPHYSICAL SURVEYS</td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IB1g(1) DEEP OCEAN AREAS</td>
<td><p>90</p>
<p>0.05</p></td>
<td colspan="2">0.03</td>
<td colspan="2">105/ 105</td>
<td>30</td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC AIR</td>
<td colspan="3"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-CEP)</strong></p></td>
<td colspan="3"><strong>Altitude (m-LEP)</strong></td>
<td colspan="4"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-CEP)</strong></p></td>
<td colspan="3"><strong>Altitude (m-LEP)</strong></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IC1 DOD AVIATION</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IC1a ENROUTE</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IC1a(1) AIRWAY</td>
<td colspan="3">3 nm (95%)</td>
<td colspan="3">-</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>(2) OCEANIC</td>
<td colspan="3">12.6 nm (95%)</td>
<td colspan="3">-</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>(3) LOW LEVEL</td>
<td colspan="3">50 (95%)</td>
<td colspan="3">± 22.5</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>(4) RNAV</td>
<td colspan="3">3 nm (95%)</td>
<td colspan="3">-</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>(5) TERMINAL</td>
<td colspan="3">2 nm (95%)</td>
<td colspan="3">-</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1b APPROACH/LANDING</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IC1b(1) NONPRECISION</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IC1b(1)(a) LAND</td>
<td colspan="3">.6 nm (95%)</td>
<td colspan="3">-</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>(b) SEA</td>
<td colspan="3">± 12 (95%)</td>
<td colspan="3">± 3</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1b(2) PRECISION</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IC1b(2)(a) LAND</td>
<td colspan="3">± 17.1 (95%)</td>
<td colspan="3">± 1.7</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>(i) PFE (Horizontal)</td>
<td colspan="3">5.5</td>
<td colspan="3"></td>
<td colspan="4">4.4</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="even">
<td>(ii) PFE (Vertical)</td>
<td colspan="3">1.8</td>
<td colspan="3"></td>
<td colspan="4">1.3</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="odd">
<td>(iii) PFN (Horizontal)</td>
<td colspan="3">3.4</td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="even">
<td>(iv) PFN (Vertical)</td>
<td colspan="3">0.5</td>
<td colspan="3"></td>
<td colspan="4">0.4</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="odd">
<td>(v) CMN (Horizontal)</td>
<td colspan="3">3.6</td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="even">
<td>(vi) CMN (Vertical)</td>
<td colspan="3">0.7</td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="odd">
<td>(b) SEA</td>
<td colspan="3">± 0.6 (95%)</td>
<td colspan="3">± 0.6</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td></td>
<td colspan="3"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-CEP)</strong></p></td>
<td colspan="3"><strong>Altitude (m-LEP)</strong></td>
<td colspan="4"><p><strong>Horizontal Position</strong></p>
<p><strong>(m-CEP)</strong></p></td>
<td colspan="3"><strong>Altitude (m-LEP)</strong></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>(i) PFE (Horizontal)</td>
<td colspan="3">.35</td>
<td colspan="3"></td>
<td colspan="4">.2</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="even">
<td>(ii) PFE (Vertical)</td>
<td colspan="3">.35</td>
<td colspan="3"></td>
<td colspan="4">.2</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="odd">
<td>(iii) PFN (Horizontal)</td>
<td colspan="3">.25</td>
<td colspan="3"></td>
<td colspan="4">.16</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="even">
<td>(iv) PFN (Vertical)</td>
<td colspan="3">.2</td>
<td colspan="3"></td>
<td colspan="4">.1</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="odd">
<td>(v) CMN (Horizontal)</td>
<td colspan="3">.25</td>
<td colspan="3"></td>
<td colspan="4">.16</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="even">
<td>(vi) CMN (Vertical)</td>
<td colspan="3">.2</td>
<td colspan="3"></td>
<td colspan="4">.1</td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="odd">
<td>IC1b(3) UNPREPARED SURFACE</td>
<td colspan="3">± 12.5 (95%)</td>
<td colspan="3">-</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1c AIR DROP</td>
<td colspan="3">50.0</td>
<td colspan="3">91.0</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1d AMPHIBIOUS WARFARE</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IC1d(1) TRANSPORT</td>
<td colspan="3">50</td>
<td colspan="3">3.0</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1d(2) ATTACK</td>
<td colspan="3">50</td>
<td colspan="3">3.0</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1e ANTISUBMARINE/ ANTISURFACE WARFARE</td>
<td colspan="3">50.0</td>
<td colspan="3">3.0</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1f ANTIAIR WARFARE</td>
<td colspan="3">18.1</td>
<td colspan="3">29.7</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1g STRATEGIC BOMBING</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IC1g(1) CONVENTIONAL</td>
<td colspan="3">37.5</td>
<td colspan="3">22.50</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1g(2) NUCLEAR</td>
<td colspan="3">75.0</td>
<td colspan="3">22.50</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1h CLOSE AIR SUPPORT/ INTERDICTION</td>
<td colspan="3">9.0</td>
<td colspan="3">21.75</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1i ELECTRONIC WARFARE</td>
<td colspan="3">22.5</td>
<td colspan="3">22.50</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1j C3</td>
<td colspan="3">37.5</td>
<td colspan="3">43.50</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1k MAPPING</td>
<td colspan="3">50.0</td>
<td colspan="3">50.00</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1l SEARCH, RESCUE, MED-EVAC INSERTION, EXTRACTION</td>
<td colspan="3">125.0</td>
<td colspan="3">21.75</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1m AIR REFUELING</td>
<td colspan="3">370.0</td>
<td colspan="3">75.00</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1n MINE WARFARE</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IC1n(1) COUNTERMEASURES</td>
<td colspan="3">16.0</td>
<td colspan="3">3.00</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1n(2) MINE LAYING</td>
<td colspan="3">50.0</td>
<td colspan="3">3.00</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1o RECONNAISSANCE</td>
<td colspan="3">18.1</td>
<td colspan="3">58.00</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1p MAGNETIC SURVEY</td>
<td colspan="3">20.0</td>
<td colspan="3">3.00 (MOA)</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="even">
<td>IC1q GRAVITY SURVEY</td>
<td colspan="3">20.0</td>
<td colspan="3">3.00 (MOA)</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 39</td>
</tr>
<tr class="odd">
<td>IC1r PRECISION GUIDED MUNITIONS</td>
<td colspan="3">&lt; 2 m SEP</td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 4</td>
</tr>
<tr class="even">
<td>IC2 FIX RATE</td>
<td colspan="3">Continuous</td>
<td colspan="3">Continuous</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 12</td>
</tr>
<tr class="odd">
<td>IC3 FIX DIMENSION</td>
<td colspan="3">3D plus time sync</td>
<td colspan="3">3D plus time sync</td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2">REF 12</td>
</tr>
<tr class="even">
<td></td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>II SPACE</td>
<td colspan="3"><strong>3D Position</strong></td>
<td colspan="3"><strong>Attitude</strong></td>
<td colspan="4"><strong>3D Position</strong></td>
<td colspan="3"><strong>Attitude</strong></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IIA UP TO GEOSYNCH</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>IIA1 SATELLITE OPERATIONS (Near real-time)</td>
<td colspan="3">6m</td>
<td colspan="3">0.1 deg</td>
<td colspan="4">20 cm</td>
<td colspan="3">0.01 deg</td>
<td colspan="2">SATOPS ADT</td>
</tr>
<tr class="even">
<td>IIA2 SATELLITE OPERATIONS (Post-processed)</td>
<td colspan="3">1 cm w/in 72 hrs</td>
<td colspan="3">0.001 deg w/in 72 hrs</td>
<td colspan="4">1 cm w/in 1 hr</td>
<td colspan="3">0.001 deg w/in 1 hr</td>
<td colspan="2">SATOPS ADT</td>
</tr>
<tr class="odd">
<td>IIB GEO AND BEYOND (Earth Orbiting)</td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IIB1 SATELLITE OPERATIONS (Near real-time)</td>
<td colspan="3">25 m</td>
<td colspan="3">0.1 deg</td>
<td colspan="4">10 m</td>
<td colspan="3">0.01 deg</td>
<td colspan="2">SATOPS ADT</td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3"><strong>3D Position</strong></td>
<td colspan="3"><strong>Attitude</strong></td>
<td colspan="4"><strong>3D Position</strong></td>
<td colspan="3"><strong>Attitude</strong></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>IIB2 SATELLITE OPERATIONS (Post-processed)</td>
<td colspan="3">TBD</td>
<td colspan="3">TBD</td>
<td colspan="4">TBD</td>
<td colspan="3">TBD</td>
<td colspan="2">SATOPS ADT</td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3"></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
</tbody>
</table>

+----------------+-----------+-----------+-----------+-----------+----+
| **POSITION     |           |           |           |           |    |
| ACCURACY -     |           |           |           |           |    |
| CIVIL**        |           |           |           |           |    |
+================+===========+===========+===========+===========+====+
| **OPERATIONAL  | **REQUI   |           |           |           | ** |
| ENVIRONMENT/   | REMENTS** |           |           |           | SO |
| MISSION**      |           |           |           |           | UR |
|                |           |           |           |           | CE |
|                |           |           |           |           | ** |
+----------------+-----------+-----------+-----------+-----------+----+
|                | **TH      |           | **OB      |           |    |
|                | RESHOLD** |           | JECTIVE** |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| I. EARTH AND   |           |           |           |           |    |
| ATMOSPHERE     |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA LAND        |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1 SURFACE    | **HOR     | **V       | **HOR     | **V       |    |
|                | IZONTAL** | ERTICAL** | IZONTAL** | ERTICAL** |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1a HIGHWAYS  |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1a(1) NAV &  | 20 m      |           | 5 m       |           | R  |
| ROUTE GUIDE    |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(2\) VEHICLE  | 30 m      |           |           |           | R  |
| MONITORING     |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(3\) VEHICLE  | 30 m      |           |           |           | R  |
| ID             |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(4\) PUBLIC   | 10 m      |           |           |           | R  |
| SAFETY         |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(5\) RESOURCE | 5 m       |           |           |           | R  |
| MGT            |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(6\)          | 1 m       |           |           |           | R  |
| COLLISION      |           |           |           |           | EF |
| AVOIDANCE      |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(7\)          | 1 m       |           |           |           | R  |
| GEOPHYSICAL    |           |           |           |           | EF |
| SURVEY         |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(8\) GEODETIC | Sub-meter |           |           |           | R  |
| CONTROL        |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1b RAIL      |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1b(1)        | 30 m      |           | 10 m      |           | R  |
| POSITION       |           |           |           |           | EF |
| LOCATION       |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(2\) TRAIN    | 1 m       |           |           |           | R  |
| CONTROL        |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1c TRANSIT   |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1c(1)        | 50 m      |           | 30 m      |           | R  |
| VEHICLE C&C    |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(2\) BUS STOP | 5 m       |           |           |           | R  |
| AUTO VOICE     |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(3\)          | 100 m     |           | 75m       |           | R  |
| EMERGENCY RESP |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(4\) DATA     | 5 m       |           |           |           | R  |
| COLLECTION     |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(5\) FLEET    | 35 m      |           | 25 m      |           | R  |
| MONITORING     |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1d SURVEYING |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1d(1)        | 0.01 m (2 | 0.01 m (2 |           |           | R  |
| Geodetic       | sigma)    | sigma)    |           |           | EF |
| Survey         |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(2\)          | 0.15 m (2 | N/A       |           |           | R  |
| Cadastral      | sigma)    |           |           |           | EF |
| Survey         |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(3\) Crustal  | 0.001 m   | 0.001 m   |           |           | R  |
| Motion         | (2 sigma) | (2 sigma) |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(4\)          | 0.001 m   | 0.001 m   |           |           | R  |
| Deformation    | (2 sigma) | (2 sigma) |           |           | EF |
| Monitoring     |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(5\) GIS      | 0.1 - 1.0 | 0.1 - 1.0 |           |           | R  |
| (Facilities    | m (2      | m (2      |           |           | EF |
| Management)    | sigma)    | sigma)    |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| \(6\) GIS      | 1.0 - 5.0 | 1.0 - 5.0 |           |           | R  |
| (Natural       | m (2      | m (2      |           |           | EF |
| Resource       | sigma)    | sigma)    |           |           | 44 |
| Management,    |           |           |           |           |    |
| Endangered     |           |           |           |           |    |
| Species        |           |           |           |           |    |
| Studies, etc.) |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| \(7\)          | 0.1 - 1.0 | 0.1 - 1.0 |           |           | R  |
| Real-time GIS  | m (2      | m (2      |           |           | EF |
| Land           | sigma)    | sigma)    |           |           | 44 |
| Navigation     |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| \(8\) Airport  | Ho        | Or        | Ho        | Or        | F  |
| Survey -       | rizontal: | thogonal: | rizontal: | thogonal: | AA |
| Runway         | 30 cm     | 7.5 cm    | 30 cm     | 7.5 cm    |    |
|                |           |           |           |           |    |
|                |           | El        |           | El        |    |
|                |           | liptical: |           | liptical: |    |
|                |           | 6 cm      |           | 6 cm      |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA1e           | \< 5 M    |           |           |           | R  |
| PEDESTRIAN -   |           |           |           |           | EF |
| AID TO BLIND   |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA2            |           |           |           |           |    |
| SUBTERRANEAN   |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
|                | **HOR     | **V       | **HOR     | **V       |    |
|                | IZONTAL** | ERTICAL** | IZONTAL** | ERTICAL** |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA2a TRAFFIC   | 1 M       |           |           |           | R  |
| TUNNELS        |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA3            |           |           |           |           |    |
| ENVIRONMENTAL  |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA3a SITES     | 30 m      |           | 25 m      |           | R  |
|                |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA3b           | 5 m       |           | 3 m       |           | R  |
| Stationary     |           |           |           |           | EF |
| Sampling Pt    |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA3c Variable  | 5 m       |           | 0.2 m -   |           | R  |
| Sampling Pt    |           |           | 0.5 m     |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA3d Water     | 1 m       | 5 mm      | 1 m       | 5 mm      | R  |
| Level          |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA3e           | 1 m       | 0.1 m     | 0.1 m     | 1 cm      | R  |
| NAVIGATION     |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA3f Sediment  | 0.1 m     | 0.1 m     | 0.1 m     | 1 cm      | R  |
| Survey         |           |           |           |           | EF |
| (including     |           |           |           |           | 44 |
| Subsurface     |           |           |           |           |    |
| (water))       |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IA4 HEALTH     | 5 m       |           |           |           | R  |
| CARE           |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA5 LAW        | 1 m       |           |           |           | R  |
| ENFORCEMENT    |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA6            | 2 m       | 2 m       | 1 m       | 1 m       | R  |
| REC            |           |           |           |           | EF |
| REATION/SPORTS |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA7 FARMING    | 0.01 m (2 | 0.04 m (2 |           |           | R  |
|                | Sigma)    | Sigma)    |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IA8 EARTHQUAKE | 0.015 m   |           |           |           | NA |
| RESEARCH       | (post     |           |           |           | SA |
|                | process)  |           |           |           | /J |
|                |           |           |           |           | PL |
+----------------+-----------+-----------+-----------+-----------+----+
|                |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB MARINE      | **All     |           |           |           | R  |
|                | a         |           |           |           | EF |
|                | ccuracies |           |           |           | 31 |
|                | 2drms**   |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB1 Ocean      |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB1a Safety of | 7.4 km    |           | 1.8 Km    |           | R  |
| Navigation     | within 2  |           | within 15 |           | EF |
|                | hours     |           | min       |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB1b Large     | 460 m     |           | 185 m     |           | R  |
| ships -        | within 5  |           | within 5  |           | EF |
| efficiency     | min       |           | min       |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB1c Resource  | 100 m     |           | 10 m      |           | R  |
| exploration    | within 1  |           | within 1  |           | EF |
|                | min       |           | min       |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB1d Search    | 460 m     |           | 185 m     |           | R  |
| Operations     | within 1  |           | within 1  |           | EF |
|                | min       |           | min       |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB2 Coastal    |           |           |           |           | R  |
|                |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB2a Safety of | 460 m     |           |           |           | R  |
| Navigation     | within 2  |           |           |           | EF |
|                | min       |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB2b Safety    | 3.7 km    |           | 460 m     |           | R  |
| (Re            | within 5  |           | within 5  |           | EF |
| creation/Small | min       |           | min       |           | 31 |
| Vessels)       |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB2c Fishing   | 460 m     |           |           |           | R  |
|                | within 1  |           |           |           | EF |
|                | min       |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB2d Resource  | 100 m     |           | 10 m      |           | R  |
| Exploration    | within 1  |           | within 1  |           | EF |
|                | sec       |           | sec       |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB2e Search    | 0.25 m    |           |           |           | R  |
| Operations /   | within 1  |           |           |           | EF |
| Law            | min       |           |           |           | 31 |
| Enforcement    |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB3 Harbor     |           |           |           |           | R  |
| Ent            |           |           |           |           | EF |
| rance/Approach |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB3a Safety of | 20 m      |           | 8 m       |           | R  |
| Navigation     | within 10 |           | within 6  |           | EF |
|                | sec       |           | sec       |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB3b Resource  | 5 m       |           | 1 m       |           | R  |
| Exploration    | within 1  |           | within 1  |           | EF |
|                | sec       |           | sec       |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB3c           | 0.1 m     | 5 m       | 0.1 m     | 5 m       | R  |
| Engineering &  | within 2  | within 2  | within 1  | within 1  | EF |
| Construction   | sec       | sec       | sec       | sec       | 31 |
| Vessels        |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB3d           | 20 m      |           | 8 m       |           | R  |
| Recrea         |           |           |           |           | EF |
| tional/Fishing |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
|                | **HOR     | **V       | **HOR     | **V       |    |
|                | IZONTAL** | ERTICAL** | IZONTAL** | ERTICAL** |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB4 Inland     |           |           |           |           | R  |
| Waterway       |           |           |           |           | EF |
|                |           |           |           |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB4a Safety of |           |           |           |           |    |
| Navigation     |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB4a(1) Ships  | 5 m       |           | 2 m       |           | R  |
| & Tows         | within 2  |           | within 1  |           | EF |
|                | sec       |           | sec       |           | 31 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB4a(2)        | 10 m      |           | 2.5 ft    |           | R  |
| Re             | within 10 |           |           |           | EF |
| creation/Small | sec       |           |           |           | 31 |
| Vessels        |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB4b           | 0.1 m     | 5 m       | 0.1 m     | 5 m       | R  |
| Engineering &  | within 2  | within 2  | within 1  | within 1  | EF |
| Construction   | sec       | sec       | sec       | sec       | 31 |
| Vessels        |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IB5 Precision  | 10 cm (2  | 10 cm (2  |           |           | R  |
| Navigation     | sigma)    | sigma)    |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB6 Dredging   | 2 m (2    | 5 cm (2   |           |           | R  |
|                | sigma)    | sigma)    |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IB7 Marine     | 5 m (2    |           |           |           | R  |
| LIFE Science   | sigma)    |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| IC AIR         | **95% NSE | **95% NSE | **95% NSE | **95% NSE |    |
|                | Hor       | V         | Hor       | V         |    |
|                | izontal** | ertical** | izontal** | ertical** |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IC1 Enroute    | 100 m     | N/A       | 100 m     | N/A       | F  |
| through        |           |           |           |           | AA |
| Nonprecision   |           |           |           |           |    |
| Approach       |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IC2 Category I | 18.2 m    | 7.6 m     | 18.2 m    | 7.6 m     | F  |
| (CAT I)        |           |           |           |           | AA |
| Precision      |           |           |           |           |    |
| Approach       |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IC3 CATEGORY   | 6.5 m     | 1.7 m     | 6.5 m     | 1.7 m     | F  |
| II (CAT II)    |           |           |           |           | AA |
| PRECISION      |           |           |           |           |    |
| APPROACH       |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IC4 CATEGORY   | 3.9 m     | 0.8 m     | 3.9 m     | 0.8 m     | F  |
| III (CAT III)  |           |           |           |           | AA |
| PRECISION      |           |           |           |           |    |
| APPROACH       |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IC5 Airborne   | TBS       |           |           |           | R  |
| Research       |           |           |           |           | EF |
|                |           |           |           |           | 44 |
+----------------+-----------+-----------+-----------+-----------+----+
| II SPACE       | **3D      | **A       | **3D      | **A       |    |
|                | P         | ttitude** | P         | ttitude** |    |
|                | osition** |           | osition** |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IIA UP TO      |           |           |           |           |    |
| GEOSYNCH       |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IIA1 GLOBAL    | 1 m (1    |           |           |           | NA |
| TOPOGRAPHIC    | sigma)    |           |           |           | SA |
| SURVEY         | (post     |           |           |           | /J |
|                | p         |           |           |           | PL |
|                | rocessed) |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IIA2           | 0.1 m (1  |           |           |           | NA |
| I              | sigma)    |           |           |           | SA |
| NTERFEROMETRIC | (post     |           |           |           | /J |
| SYNTHETIC      | p         |           |           |           | PL |
| APERTURE RADAR | rocessed) |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IIA3 GRAVITY   | 0.005 cm  |           |           |           | NA |
| FIELD RECOVERY | (1 sigma) |           |           |           | SA |
| FROM LEO       | (post     |           |           |           | /J |
|                | p         |           |           |           | PL |
|                | rocessed) |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IIA4 TOPEX     | 1 cm (1   |           |           |           | NA |
| ALTIMETRY      | sigma)    |           |           |           | SA |
| MISSION        | (         |           |           |           | /J |
|                | vertical) |           |           |           | PL |
+----------------+-----------+-----------+-----------+-----------+----+
| IIA5 SATELLITE | 6 m       | 0.1 deg   | 20 cm     | 0.01 deg  | SA |
| OPERATIONS     |           |           |           |           | TO |
| (Near          |           |           |           |           | PS |
| Real-time)     |           |           |           |           | A  |
|                |           |           |           |           | DT |
+----------------+-----------+-----------+-----------+-----------+----+
| IIA6 SATELLITE | 1 cm      | 0.001 deg | 1 cm      | 0.001 deg | SA |
| OPERATIONS     | (w/in 72  | (w/in 72  | (w/in 1   | (w/in 1   | TO |
| (P             | hrs)      | hrs)      | hr)       | hr)       | PS |
| ost-processed) |           |           |           |           | A  |
|                |           |           |           |           | DT |
+----------------+-----------+-----------+-----------+-----------+----+
| IIB GEO AND    |           |           |           |           |    |
| BEYOND (Earth  |           |           |           |           |    |
| Orbiting)      |           |           |           |           |    |
+----------------+-----------+-----------+-----------+-----------+----+
| IIB1 SATELLITE | 25 m      | 0.1 deg   | 10 m      | 0.01 deg  | SA |
| OPERATIONS     |           |           |           |           | TO |
| (Near          |           |           |           |           | PS |
| real-time)     |           |           |           |           | A  |
|                |           |           |           |           | DT |
+----------------+-----------+-----------+-----------+-----------+----+
| IIB2 SATELLITE | TBD       | TBD       | TBD       | TBD       | SA |
| OPERATIONS     |           |           |           |           | TO |
| (P             |           |           |           |           | PS |
| ost-processed) |           |           |           |           | A  |
|                |           |           |           |           | DT |
+----------------+-----------+-----------+-----------+-----------+----+

  ----------------------------------------------------------------------------------------------------
  **VELOCITY                                                                              
  ACCURACY -                                                                              
  MILITARY**                                                                              
  -------------------- ------------------ --------------- --------------- --------------- ------------
  **OPERATIONAL        **REQUIREMENTS**                                                   **SOURCE**
  ENVIRONMENT/                                                                            
  MISSION**                                                                               

                       **THRESHOLD**                      **OBJECTIVE**                   

  I. EARTH AND                                                                            
  ATMOSPHERE                                                                              

  IA LAND              **SPEED**          **DIRECTION**   **SPEED**       **DIRECTION**   

  IA1 SURFACE          0.1 m/sec                          0.02 m/sec                      REF 35

  IA1e ARMY LAND                          Direction                                       
                                          (Mils-LEP)                                      

  IA1e(1) CHEMICAL                        1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  \(2\) ENGINEER                          1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  (2)(a) MINE NEUTRAL                     1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  (2)(b) MINE                             1.16 mils (0.4                  .29 mils (0.10  REF 35
  DISPENSING                              mils-LEP)                       mils-LEP)       

  (2)(c) GAP CROSSING                     1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  IA1e(3) FIELD                           1.16 mils (0.4                  .29 mils (0.10  REF 35
  ARTILLERY                               mils-LEP)                       mils-LEP)       

  (3)(a) MLRS                             1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  (3)(b) HOWITZER                         1.16 mils (0.4                  .29 mils (0.10  REF 35
  (TOWED)                                 mils-LEP)                       mils-LEP)       

  (3)(c) HOWITZER                         1.16 mils (0.4                  .29 mils (0.10  REF 35
  (SELF-PROPELLED)                        mils-LEP)                       mils-LEP)       

  (3)(d) MORTARS                          1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  (3)(e) FIST-V                           1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  (3)(f) FORWARD                          1.16 mils (0.4                  .29 mils (0.10  REF 35
  OBSERVER                                mils-LEP)                       mils-LEP)       

  (3)(g) ARTILLERY                        1.16 mils (0.4                  .29 mils (0.10  REF 35
  RADAR                                   mils-LEP)                       mils-LEP)       

  (4)(h) MORTAR                           1.16 mils (0.4                  .29 mils (0.10  REF 35
  LOCATING FIREFINDER                     mils-LEP)                       mils-LEP)       
  RADAR                                                                                   

  IA1e(4) INFANTRY                        1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  IA1e(5) MISSILE                         1.16 mils (0.4                  .29 mils (0.10  REF 35
  MUNITIONS                               mils-LEP)                       mils-LEP)       

  IA1e (6) SIGNAL                         1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  IA1e(7)                                 1.16 mils (0.4                  .29 mils (0.10  REF 35
  TRANSPORATION                           mils-LEP)                       mils-LEP)       
  (WHEELED VEHICLE)                                                                       

  IA1e(8) SOLDIER                         1.16 mils (0.4                  .29 mils (0.10  REF 35
  SUPPORT                                 mils-LEP)                       mils-LEP)       

  IA1e(9) ARMOR                           1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  IA1e(10) MILITARY                       1.16 mils (0.4                  .29 mils (0.10  REF 35
  POLICE                                  mils-LEP)                       mils-LEP)       

  IA1e(11) SPECIAL OPS                    1.16 mils (0.4                  .29 mils (0.10  REF 35
  FORCES                                  mils-LEP)                       mils-LEP)       

  IA1e(12)                                1.16 mils (0.4                  .29 mils (0.10  REF 35
  INTELLIGENCE                            mils-LEP)                       mils-LEP)       
  ELECTRONIC WARFARE                                                                      

  IA1e(13)                                1.16 mils (0.4                  .29 mils (0.10  REF 35
  QUARTERMASTER                           mils-LEP)                       mils-LEP)       

  IA1e(14) ORDINANCE                      1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  IA1e(15) AIR DEFENSE                                                                    
  ARTILLERY                                                                               

  IA1e(15)(a) PATRIOT                     1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  IA1e(16)(b) HAWK                        1.16 mils (0.4                  .29 mils (0.10  REF 35
                                          mils-LEP)                       mils-LEP)       

  IB MARINE                                                                               

  IB1 NAVY             **Speed            **HEADING       **Speed         **HEADING       
                       (Km/Hr-LEP)**      (DEG-LEP)**     (Km/Hr-LEP)**   (DEG-LEP)**     

  IB1a ENROUTE                                                                            
  NAVIGATION                                                                              

  IB1a(1) PILOTAGE                        0.8                                             REF 39
  WATERS                                                                                  

  \(2\) COASTAL WATERS                    0.8                                             REF 39

  \(3\) INLAND WATERS                     0.8                                             REF 39

  \(4\) OPEN WATERS                       0.8                                             REF 39

  \(5\) RENDEVOUS                         0.8                                             REF 39

                                                                                          

  IB1b MINE WARFARE    0.2 m/sec (2                                                       REF 4
                       sigma)                                                             

  IB1c SPECIAL WARFARE                                                                    

  IB1c(1) PARADROP     1.85               1                                               REF 39

  \(2\) SMALL CRAFT    0.93               1                                               REF 39

  \(3\) COMBAT                                                                            
  SWIMMING                                                                                

  IB1c(3)(a) ENROUTE   0.24               0.5                                             REF 39

  \(b\) RENDEVOUS      0.24               0.5                                             REF 39

  IB1c(4) LAND WARFARE                                                                    

  IB1c(4)(a) ENROUTE   0.12               1                                               REF 39

  IB1c(4)(b) RENDEVOUS 0.12               1                                               REF 39

  IB1c(5) INSERTION    0.12               1                                               REF 39

  IB1c(6) EXTRACTION   0.12               1                                               REF 39

  IB1g GEOPHYSICAL                                                                        
  SURVEYS                                                                                 

  IB1g(1) DEEP OCEAN   0.05               0.03                                            REF 39
  AREAS                                                                                   

  IC AIR                                                                                  

  IC1 DOD AVIATION     **Velocity                                                         
                       (Km/Hr-LEP)**                                                      

  IC1a ENROUTE                                                                            

  IC1a(1) AIRWAY                                                                          

  IC1a(1)(a) LOW LEVEL 0.1                                                                REF 39

  IC1b                                                                                    
  APPROACH/LANDING                                                                        

  IC1b(2) PRECISION                                                                       

  IC1b(2)(b) SEA       0.9                                                                REF 39

  IC1d AMPHIBIOUS                                                                         
  WARFARE                                                                                 

  IC1d(1) TRANSPORT    3.7                                                                REF 39

  IC1d(2) ATTACK       3.7                                                                REF 39

  IC1e ANTISUBMARINE.  3.7                                                                REF 39
  ANTISURFACE WARFARE                                                                     

  IC1f ANTIAIR WARFARE 5.0                                                                REF 39

                       **Velocity                                                         
                       (Km/Hr-LEP)**                                                      

  IC1g STRATEGIC                                                                          
  BOMBING                                                                                 

  IC1g(1) CONVENTIONAL 0.10                                                               REF 39

  IC1g(2) NUCLEAR      0.10                                                               REF 39

  IC1h CLOSE AIR       0.10                                                               REF 39
  SUPPORT/                                                                                
  INTERDICTION                                                                            

  IC1i ELECTRONIC      0.30                                                               REF 39
  WARFARE                                                                                 

  IC1j C3              0.10                                                               REF 39

  IC1m AIR REFUELING   0.10                                                               REF 39

  IC1n MINE WARFARE                                                                       

  IC1n(1)              3.70                                                               REF 39
  COUNTERMEASURES                                                                         

  IC1n(2) MINE LAYING  3.70                                                               REF 39

  IC1oRECONNAISSANCE   0.03                                                               REF 39

  IC1p MAGNETIC SURVEY 0.10 m/SEC                                                         REF 39

  IC1q GRAVITY SURVEY  0.10 m/SEC                                                         REF 39

  IC1r PRECISION       0.2 m/sec (2                                                       REF 4
  GUIDED MISSILES      sigma)                                                             

                       **m/sec**                          **m/sec**                       

  II SPACE             0.001 m/sec                        \< 0.0001 m/sec                 SATOPS ADT

  IIA UP TO GEOSYNCH                                                                      

  IIB GEO AND BEYOND                                                                      
  (Earth Orbiting)                                                                        
  ----------------------------------------------------------------------------------------------------

  ------------------------------------------------------------------------------------------------
  **VELOCITY                                                                          
  ACCURACY -                                                                          
  CIVIL**                                                                             
  ---------------- ------------------ --------------- --------------- --------------- ------------
  **OPERATIONAL    **REQUIREMENTS**                                                   **SOURCE**
  ENVIRONMENT/                                                                        
  MISSION**                                                                           

                   **THRESHOLD**                      **OBJECTIVE**                   

  I. EARTH AND                                                                        
  ATMOSPHERE                                                                          

  IA LAND          **SPEED**          **DIRECTION**   **SPEED**       **DIRECTION**   

  IA1 SURFACE      0.4 m/sec                                                          REF 44
                   (real-time)                                                        

  IB MARINE                                                                           

  IB1a Marine Life 0.05 m/sec                                                         REF 44
  Sciences                                                                            

  IC AIR           2 m/s                              2 m/s                           FAA

  II SPACE                                                                            

  IIA UP TO                                                                           
  GEOSYNCH                                                                            

  IIA1             .001 m / sec                                                       NASA/JPL
  GPS/MET:UPPER    (post-Processed)                                                   
  ATMOSPHERE                                                                          
  TEMPERATURE                                                                         
  PROFILE RECIVERY                                                                    

  IIA2 BISTATIC    0.0001 m / sec                                                     NASA/JPL
  RADAR            (real time)                                                        

  IIA3 SATELLITE   0.001 m/sec                        \< 0.0001 m/sec                 SATOPS ADT
  OPERATIONS                                                                          

  IIB GEO AND                                                                         
  BEYOND (Earth                                                                       
  Orbiting)                                                                           

  IiB1 SATELLITE   0.001 m/sec                        \< 0.0001 m/sec                 SATOPS ADT
  OPERATIONS                                                                          

                                                                                      

                                                                                      

                                                                                      

                                                                                      

                                                                                      

                                                                                      

                                                                                      

                                                                                      

                                                                                      
  ------------------------------------------------------------------------------------------------

+----------------+-----------------------+-----------------------+----+
| **INTEGRITY -  |                       |                       |    |
| MILITARY**     |                       |                       |    |
+================+=======================+=======================+====+
| **OPERATIONAL  | **REQUIREMENTS**      |                       | ** |
| ENVIRONMENT/   |                       |                       | SO |
| MISSION**      |                       |                       | UR |
|                |                       |                       | CE |
|                |                       |                       | ** |
+----------------+-----------------------+-----------------------+----+
|                | **THRESHOLD**         | **OBJECTIVE**         |    |
+----------------+-----------------------+-----------------------+----+
| I. EARTH AND   |                       |                       |    |
| ATMOSPHERE     |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IA LAND        |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IA1 SURFACE    |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IA2            |                       |                       |    |
| SUBTERRANEAN   |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IB MARINE      |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC AIR         | **time(sec) /         |                       |    |
|                | probability**         |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC1 EN ROUTE   |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC1a AIRWAY    |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| \(1\) HMI      | 10^-7^ per approach   |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(2\) Alarm    | 556 m                 |                       | R  |
| Limit          |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(3\) Time to  | 10 sec                |                       | RE |
| Alarm          |                       |                       | F4 |
+----------------+-----------------------+-----------------------+----+
| IC1b Oceanic   |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| \(1\) HMI      | 10^-7^ per approach   |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(2\) Alarm    | 556 m                 |                       | R  |
| Limit          |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(3\) Time to  | 10 sec                |                       | RE |
| Alarm          |                       |                       | F4 |
+----------------+-----------------------+-----------------------+----+
| IC1c Low Level | 10 / .999             |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 39 |
+----------------+-----------------------+-----------------------+----+
| IC1d RNAV      | 30 / .999             |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 39 |
+----------------+-----------------------+-----------------------+----+
| IC1e TerminaL  | 10 / .999             |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 39 |
+----------------+-----------------------+-----------------------+----+
| IC2            |                       |                       |    |
| AP             |                       |                       |    |
| PROACH/LANDING |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC2a           |                       |                       |    |
| NONPRECISION   |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC2a(1) LAND   |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| \(i\) HMI      | 10^-7^ per approach   |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(ii\) Alarm   | 556 m                 |                       | R  |
| Limit          |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(iii\) Time   | 10 sec                |                       | RE |
| to Alarm       |                       |                       | F4 |
+----------------+-----------------------+-----------------------+----+
| IC2a(2) SEA    |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| \(i\) HMI      | 10^-7^ per approach   |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(ii\) Alarm   | 556 m                 |                       | R  |
| Limit          |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(iii\) Time   | 10 sec                |                       | RE |
| to Alarm       |                       |                       | F4 |
+----------------+-----------------------+-----------------------+----+
| IC2b PRECISION |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC2b(1) LAND   |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| \(i\) HMI      | 4x10^-8^ per approach |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(ii\) Alarm   | 4.5 m                 |                       | R  |
| Limit          |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(iii\) Time   | 2 sec                 |                       | RE |
| to Alarm       |                       |                       | F4 |
+----------------+-----------------------+-----------------------+----+
| IC2b(2) SEA    |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| \(i\) HMI      | 1x10^-7^ per approach |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(ii\) Alarm   | 1.1 m                 |                       | R  |
| Limit          |                       |                       | EF |
|                |                       |                       | 4  |
+----------------+-----------------------+-----------------------+----+
| \(iii\) Time   | 1 sec                 |                       | RE |
| to Alarm       |                       |                       | F4 |
+----------------+-----------------------+-----------------------+----+
| IC2c           | 6 / .999              |                       | R  |
| UNPREPARED     |                       |                       | EF |
| SURFACE        |                       |                       | 39 |
+----------------+-----------------------+-----------------------+----+
|                |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| II SPACE       | Monitor 24 hr/day up  | Monitor 24 hr/day up  | SA |
|                | to geosynchronous     | to geosynchronous     | TO |
|                | altitude, 100%        | altitude              | PS |
|                | monitoring below      |                       | A  |
|                | 10,000 km altitude    | Time to alarm 3 sec   | DT |
|                |                       |                       |    |
|                | Time to alarm 6 sec   |                       |    |
+----------------+-----------------------+-----------------------+----+
| IIA UP TO      |                       |                       |    |
| GEOSYNCH       |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IIB GEO AND    |                       |                       |    |
| BEYOND (Earth  |                       |                       |    |
| Orbiting)      |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
|                |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IIIA SYSTEM    | 24 hours/day globally |                       | R  |
| MONITORING     |                       |                       | EF |
|                |                       |                       | 12 |
+----------------+-----------------------+-----------------------+----+
| IIIB STATUS    | \< 60 sec             |                       |    |
| UPDATE         |                       |                       |    |
+----------------+-----------------------+-----------------------+----+

+----------------+-----------------------+-----------------------+----+
| **INTEGRITY -  |                       |                       |    |
| CIVIL**        |                       |                       |    |
+================+=======================+=======================+====+
| **OPERATIONAL  | **REQUIREMENTS**      |                       | ** |
| ENVIRONMENT/   |                       |                       | SO |
| MISSION**      |                       |                       | UR |
|                |                       |                       | CE |
|                |                       |                       | ** |
+----------------+-----------------------+-----------------------+----+
|                | **THRESHOLD**         | **OBJECTIVE**         |    |
+----------------+-----------------------+-----------------------+----+
| I. EARTH AND   |                       |                       |    |
| ATMOSPHERE     |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IA LAND        |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IA1 SURFACE    | 10 sec to alarm       | 5 sec to alarm        | R  |
|                |                       |                       | EF |
|                |                       |                       | 44 |
+----------------+-----------------------+-----------------------+----+
| IB MARINE      | 10 sec to alarm       |                       | R  |
|                |                       |                       | EF |
|                |                       |                       | 44 |
+----------------+-----------------------+-----------------------+----+
| IC AIR         |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC1 Enroute    | 1-10^-5^/hour         | 1-10^-5^/hour         | F  |
| through        |                       |                       | AA |
| non-precision  |                       |                       |    |
| approach       |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC1a TIME TO   | 10 seconds            | 10 seconds            | F  |
| ALERT          |                       |                       | AA |
+----------------+-----------------------+-----------------------+----+
| IC2 CATEGORY I | 1-3.5 x 10^-7^ per    | 1-3.5 x 10^-7^ per    | F  |
| PRECISION      | approach              | approach              | AA |
| APPROACH       |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC2a TIME TO   | 6 seconds             | 6 seconds             | F  |
| ALERT I        |                       |                       | AA |
+----------------+-----------------------+-----------------------+----+
| IC3 CATEGORY   | 1 - 2.5 X 10^-9^ per  | 1 - 2.5 X 10^-9^ per  | F  |
| II PRECISION   | approach              | approach              | AA |
| APPROACH       |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC3a TIME TO   | 1 second              | 1 second              | F  |
| ALERT          |                       |                       | AA |
+----------------+-----------------------+-----------------------+----+
| IC4 CATEGORY   | 1 - 2 X 10^-9^ per    | 1 - 2 X 10^-9^ per    | F  |
| III PRECISION  | approach              | approach              | AA |
| APPROACH       |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IC4a TIME TO   | 1 second              | 1 second              | F  |
| ALERT          |                       |                       | AA |
+----------------+-----------------------+-----------------------+----+
| II SPACE       | Monitor 24 hr/day up  | Monitor 24 hr/day up  | SA |
|                | to geosynchronous     | to geosynchronous     | TO |
|                | altitude, 100%        | altitude              | PS |
|                | monitoring below      |                       | A  |
|                | 10,000 km altitude    | Time to alarm 3 sec   | DT |
|                |                       |                       |    |
|                | Time to alarm 6 sec   |                       |    |
+----------------+-----------------------+-----------------------+----+
| IIA UP TO      |                       |                       |    |
| GEOSYNCH       |                       |                       |    |
+----------------+-----------------------+-----------------------+----+
| IIB GEO AND    |                       |                       |    |
| BEYOND (Earth  |                       |                       |    |
| Orbiting)      |                       |                       |    |
+----------------+-----------------------+-----------------------+----+

  ---------------------------------------------------------------------------------
  **AVAILABILITY -                                                     
  MILITARY**                                                           
  ------------------ ------------------------ ------------------------ ------------
  **OPERATIONAL      **REQUIREMENTS**                                  **SOURCE**
  ENVIRONMENT/                                                         
  MISSION**                                                            

                     **THRESHOLD**            **OBJECTIVE**            

  I. EARTH AND                                                         
  ATMOSPHERE                                                           

  IA LAND                                                              

  IA1 SURFACE                                                          

  IA1e ARMY                                                            

  IA1e(1) CHEMICAL                                                     

  IA1e(1) ENGINEER                                                     

  IA1e(1)(a) MINE                                                      
  NEUTRAL                                                              

  IA1e(1)(b) MINE                                                      
  DISPENSING                                                           

  IA1e(1)(c)                                                           

  IA2 SUBTERRANEAN                                                     

  IB MARINE                                                            

  IC AIR                                                               

  IC1 EN ROUTE                                                         

  IC1a AIRWAY        99.999%                                           REF 4

  IC1b OCEANIC       99.999%                                           REF 4

  IC2                                                                  
  APPROACH/LANDING                                                     

  IC2b PRECISION                                                       

  IC2b(1) LAND                                                         

  \(i\) SINGLE       99.8%                    99.9%                    REF 4
  RUNWAY                                                               

  \(ii\) MULTIPLE    99.99%                   99.999%                  REF 4
  AIRPORTS                                                             

  IC2B(2) SEA        99.8%                                             REF 4

  II SPACE           100% over 24 hours       100% over 24 hours       SATOPS ADT

  IIA UP TO GEOSYNCH                                                   

  IIB GEO AND BEYOND                                                   
  (Earth Orbiting)                                                     

  SERVICE            98%, OVER 24 HOUR PERIOD 100% OVER 24 HOUR PERIOD REF 12
  AVAILABILITY                                                         

  SERVICE            98%                      99.79%                   REF 12
  RELIABILITY                                                          

                                                                       

                                                                       
  ---------------------------------------------------------------------------------

  ---------------------------------------------------------------------------------
  **AVAILABILITY -                                                     
  CIVIL**                                                              
  ------------------ ------------------------ ------------------------ ------------
  **OPERATIONAL      **REQUIREMENTS**                                  **SOURCE**
  ENVIRONMENT/                                                         
  MISSION**                                                            

                     **THRESHOLD**            **OBJECTIVE**            

  I. EARTH AND                                                         
  ATMOSPHERE                                                           

  A LAND                                                               

  IA1 SURFACE        100% over 24 hours                                Ref 44

  IA2 SUBTERRANEAN                                                     

  IB MARINE          99.9%                                             

  IB1 Ocean                                                            

  IB1a All Craft     99% fix at least every                            Ref 31
                     12 hours                                          

  IB1b Large Ships   99%                                               Ref 31

  IB1c Resource      99%                                               Ref 31
  Exploration                                                          

  IB1d Search        99%                                               Ref 31
  Operations                                                           

  IB2 Coastal                                                          

  IB2a All Ships     99.7%                                             Ref 31

  IB2b Recreation    99%                                               Ref 31
  Boats/Small                                                          
  Vessels                                                              

  IB2c Commercial    99%                                               Ref 31
  Fishing                                                              

  IB2d Resource      99%                                               Ref 31
  Exploration                                                          

  IB2e Search        99.7%                                             Ref 31
  Operations, Law                                                      
  Enforcement                                                          

  IB2f Recreational  99%                                               Ref 31
  Sports Fishing                                                       

  IB3 Harbor                                                           
  Entrance/ Approach                                                   

  IB3a Large Ships   99.7%                                             Ref 31
  and Tows                                                             

  IB3b Smaller Ships 99.9%                                             Ref 31

  IB3c Resource      99%                                               Ref 31
  Exploration                                                          

  IB3d Engineering & 99%                                               Ref 31
  Construction                                                         
  Vessels                                                              

  IB3e Fishing,      99.7%                                             Ref 31
  Recreation, Other                                                    
  Small Vessels                                                        

  IB4 Inland                                                           
  Waterway                                                             

  IB4a All Ships and 99.9%                                             Ref 31
  Tows                                                                 

  IB4b Recreation    99%                                               Ref 31
  Boats/Smaller                                                        
  Vessels                                                              

  IC AIR                                                               

  IC1 ENROUTE        99.999% (3-dimensional), 99.999% (3-dimensional), FAA
  THROUGH            Mask angle 5 degrees     Mask angle 5 degrees     
  NON-PRECISION      above horizon            above horizon            
  APPROACH                                                             

  IC2 CATEGORY I     99.9% (3-dimensional),   99.9% (3-dimensional),   FAA
  PRECISION APPROACH Mask angle 5 degrees     Mask angle 5 degrees     
                     above horizon            above horizon            

  IC3 CATEGORY II    99.9% (3-dimensional),   99.9% (3-dimensional),   FAA
  PRECISION APPROACH Mask angle 5 degrees     Mask angle 5 degrees     
                     above horizon            above horizon            

  IC4 CATEGORY III   99.9% (3-dimensional),   99.9% (3-dimensional),   FAA
  PRECISION APPROACH Mask angle 5 degrees     Mask angle 5 degrees     
                     above horizon            above horizon            

  II SPACE           100% over 24 hrs         100% over 24 hrs         SATOPS ADT

  IIA UP TO GEOSYNCH                                                   

  IIB GEO AND BEYOND                                                   
  (Earth Orbiting)                                                     

                                                                       

  III PVT SYSTEM                                                       

  IIIA SERVICE       98 %                     99.999 %                 Ref 12
  AVAILABILITY                                                         

  IIIB SERVICE       98 %                     99.97 %                  Ref 12
  RELIABILITY                                                          
  ---------------------------------------------------------------------------------

  -------------------------------------------------------------------------------
  **TIMING                                                           
  ACCURACY -                                                         
  MILITARY**                                                         
  ---------------- ------------------------ ------------------------ ------------
  **OPERATIONAL    **REQUIREMENTS**                                  **SOURCE**
  ENVIRONMENT/                                                       
  MISSION**                                                          

                   **THRESHOLD**            **OBJECTIVE**            

  I. EARTH AND                                                       
  ATMOSPHERE                                                         

  IA LAND                                                            

  IA1 SURFACE                                                        

  IA1a             1 MICROSECOND ACCURACY                            REF 39
  COMMUNICATIONS   TO UTC (USNO)                                     
  SITES                                                              

  IA1b RADAR SITES \< 1 MICROSECOND                                  REF 39
                   ACCURACY TO UTC (USNO)                            

  IA1c ECCM COMM,  10 nanosec to 5 MICROSEC                          REF 39
  RADAR AND        ACCURACY TO UTC (USNO)                            
  SURVEILLANCE                                                       
  SYSTEMS                                                            

  IA1e ARMY LAND   100 nsec                 10 nsec                  Army CCSD-OP

  IA2 SUBTERRANEAN                                                   

  IB MARINE                                                          

  IB1 NAVY         TIME/TIME INTERVAL                                
                   (SEC-1 SIGMA)                                     

  IB1a ENROUTE                                                       
  NAVIGATION                                                         

  IB1a(3) INLAND   0.025                                             REF 39
  WATERS                                                             

  IB1b MINE        \< 10 nsec                                        REF 4
  WARFARE                                                            

  IB1c SPECIAL                                                       
  WARFARE                                                            

  IB1c(1) PARADROP 10                                                REF 39

  \(2\) SMALL      30                                                REF 39
  CRAFT                                                              

  \(3\) COMBAT                                                       
  SWIMMING                                                           

  (3)(a) ENROUTE   30                                                REF 39

  (3)(b) RENDEVOUS                                                   

  \(4\) LAND                                                         
  WARFARE                                                            

  (4)(a) ENROUTE   10                                                REF 39

  (4)(B) RENDEVOUS 10                                                REF 39

  \(5\) INSERTION  10                                                REF 39

  \(6\) EXTRACTION 10                                                REF 39

  IB1f                                                               
  HYDROGRAPHIC/                                                      
  OCEANOGRAPHIC                                                      
  SURVEYS                                                            

  IB1f(1)          20                                                REF 39
  HYDROGRAPHIC                                                       
  SURVEY                                                             

  IC AIR                                                             

  IC1 PRECISION    \< 10 nsec                                        REF 4
  GUIDED MISSILES                                                    

  IC2 LOW ACCURACY 1 MILLISECOND ACCURACY                            
  AIRCRAFT         TO UTC (USNO)                                     

  II SPACE                                                           

  IIA PPS TIME     20 nsec                  1 nsec                   REF 12
  TRANSFER OF UTC                                                    
  (USNO)                                                             

  IIB Satellite    25 nsec                  0.01 nsec                SATOPS ADT
  Operations                                (post-processed)         
  -------------------------------------------------------------------------------

  -------------------------------------------------------------------------------
  **TIMING                                                           
  ACCURACY -                                                         
  CIVIL**                                                            
  ---------------- ------------------------ ------------------------ ------------
  **OPERATIONAL    **REQUIREMENTS**                                  **SOURCE**
  ENVIRONMENT/                                                       
  MISSION**                                                          

                   **THRESHOLD**            **OBJECTIVE**            

  I. EARTH AND                                                       
  ATMOSPHERE                                                         

  IA LAND                                                            

  IA1 SURFACE      10 ns                    1 nsec                   REF 44

  IA1a POWER GRIDS 1 microsecond                                     REF 44

  IA1b UTC TO USNO 10 nsec                                           REF 44
  TIME                                                               
  DIFFERENTIAL                                                       

  IB MARINE                                                          

  IC AIR                                                             

  IC1 ADS \*       5 msec                   5 msec                   FAA
  COMMUNICATIONS                                                     
  USING TDMA                                                         

  II SPACE                                                           

  IIA SPS Time     340 nsec (95%)           340 nsec (95%)           Ref 12
  Transfer from                                                      
  UTC                                                                

  IIB HYDROGEN     1 nsec                                            NASA/JPL
  MASER IN SPACE                                                     

  IIC MEASURE      0.1 nsec (1 sigma)                                NASA/JPL
  MASER STABILITY                                                    

  IID Satellite    25 nsec                  0.01 nsec                SATOPS ADT
  Operations                                (post-processed)         
  -------------------------------------------------------------------------------

\* ADS = Automatic Dependent Surveillance

  -------------------------------------------------------------------------------
  **COVERAGE -                                                       
  MILITARY**                                                         
  ---------------- ------------------------ ------------------------ ------------
  **OPERATIONAL    **REQUIREMENTS**                                  **SOURCE**
  ENVIRONMENT/                                                       
  MISSION**                                                          

                   **THRESHOLD**            **OBJECTIVE**            

  I. EARTH AND                                                       
  ATMOSPHERE                                                         

  IA LAND                                                            

  IA1 SURFACE      100% when unobstructed                            REF 12
                   by natural or man-made                            
                   structure                                         

  IA2 SUBTERRANEAN TBD                                               

  IB MARINE        Worldwide through all                             REF 12
                   operating environments                            

  IC AIR           Worldwide through all                             REF 12
                   operating environments                            

                                                                     

  II SPACE         Worldwide to             Worldwide to twice       SATOPS ADT
                   geostationary altitude   geostationary altitude   
                                            (supporting highly       
                                            elliptical orbit         
                                            satellites)              

  IIA UP TO                                                          
  GEOSYNCH                                                           

  IIB GEO AND                                                        
  BEYOND (Earth                                                      
  Orbiting)                                                          

                                                                     

                                                                     

                                                                     
  -------------------------------------------------------------------------------

  -------------------------------------------------------------------------------
  **COVERAGE -                                                       
  CIVIL**                                                            
  ---------------- ------------------------ ------------------------ ------------
  **OPERATIONAL    **REQUIREMENTS**                                  **SOURCE**
  ENVIRONMENT/                                                       
  MISSION**                                                          

  I. EARTH AND     **THRESHOLD**            **OBJECTIVE**            
  ATMOSPHERE                                                         

  IA LAND                                                            

  IA1 SURFACE      Worldwide through all                             REF 44
                   operating environments                            

  IA2 SUBTERRANEAN                                                   

  IB MARINE        Worldwide through all                             REF 44
                   operating environments                            

  IC AIR           Global (per availability Global (per availability FAA
                   and continuity of        and continuity of        
                   service requirements)    service requirements)    

                                                                     

  II SPACE         Worldwide to             Worldwide to twice       SATOPS ADT
                   geostationary altitude   geostationary altitude   
                                            (supporting highly       
                                            elliptical orbit         
                                            satellites)              

  IIA UP TO                                                          
  GEOSYNCH                                                           

  IIB GEO AND                                                        
  BEYOND (Earth                                                      
  Orbiting)                                                          

                                                                     

                                                                     

                                                                     
  -------------------------------------------------------------------------------

  ---------------------------------------------------------------------------------
  **CONTINUITY OF                                                      
  SERVICE -                                                            
  MILITARY**                                                           
  ------------------ ------------------------ ------------------------ ------------
  **OPERATIONAL      **REQUIREMENTS**                                  **SOURCE**
  ENVIRONMENT/                                                         
  MISSION**                                                            

                     **THRESHOLD**            **OBJECTIVE**            

  I. EARTH AND                                                         
  ATMOSPHERE                                                           

  IA LAND                                                              

  IA1 SURFACE                                                          

  IA2 SUBTERRANEAN                                                     

  IB MARINE                                                            

  IC AIR                                                               

  IC1 EN ROUTE                                                         

  IC1a AIRWAY                                                          

  Multiple Craft \>  10^-8^ / hr                                       REF 4
  200 nm                                                               

  Multiple Craft \<  10^-6^ / hr                                       REF 4
  200 nm                                                               

  Single Craft       10^-4^                                            REF 4

  IC1b Oceanic                                                         

  Multiple Craft \>  10^-8^ / hr                                       REF 4
  200 nm                                                               

  Multiple Craft \<  10^-6^ / hr                                       REF 4
  200 nm                                                               

  Single Craft       10^-4^                                            REF 4

  IC2                                                                  
  APPROACH/LANDING                                                     

  IC2a NONPRECISION                                                    

  IC2a(1) LAND                                                         

  Multiple Craft \>  10^-8^ / hr                                       REF 4
  200 nm                                                               

  Multiple Craft \<  10^-6^ / hr                                       REF 4
  200 nm                                                               

  Single Craft       10^-4^                                            REF 4

  IC2a(2) SEA                                                          

  Multiple Craft \>  10^-8^ / hr                                       REF 4
  200 nm                                                               

  Multiple Craft \<  10^-6^ / hr                                       REF 4
  200 nm                                                               

  Single Craft       10^-4^                                            REF 4

  IC2b PRECISION                                                       

  IC2b(1) LAND       \<2X10^-5^ per approach                           REF 4

  IC2b(2) SEA                                                          

  \(a\) Air Capable  2X10^-5^ per approach                             REF 4
  Ship                                                                 

  \(b\) Last 12      HMI rate                                          REF 4
  seconds                                                              

  II SPACE                                                             

  IIA UP TO GEOSYNCH                                                   

  IIB GEO AND BEYOND                                                   
  (Earth Orbiting)                                                     
  ---------------------------------------------------------------------------------

  -------------------------------------------------------------------------------
  **CONTINUITY OF                                                    
  SERVICE -                                                          
  CIVIL**                                                            
  ---------------- ------------------------ ------------------------ ------------
  **OPERATIONAL    **REQUIREMENTS**                                  **SOURCE**
  ENVIRONMENT/                                                       
  MISSION**                                                          

                   **THRESHOLD**            **OBJECTIVE**            

  I. EARTH AND                                                       
  ATMOSPHERE                                                         

  IA LAND                                                            

  IA1 SURFACE                                                        

  IA2 SUBTERRANEAN                                                   

  IB MARINE                                                          

  IC AIR                                                             

  IC1 ENROUTE THRU 1 - 10^-4^ per hour      1 - 10^-4^ per hour      FAA
  NON PRECISION                                                      
  APPROACH                                                           

                                                                     

                                                                     

  IC2 CAT I        1 - 10^-5^ (in any 15    1 - 10^-5^ (in any 15    FAA
  PRECISION        second time period)      second time period)      
  APPROACH                                                           

                                                                     

  IC3 CAT II       1 - 8 x 10^-6^ (in any   1 - 8 x 10^-6^ (in any   FAA
  PRECISION        15 second time period)   15 second time period)   
  APPROACH                                                           

                                                                     

  IC4 CAT III      1 - 6 x 10^-6^ (in any   1 - 6 x 10^-6^ (in any   FAA
  PRECISION        30 second time period)   30 second time period)   
  APPROACH                                                           

                                                                     

  II SPACE                                                           

  IIA UP TO                                                          
  GEOSYNCH                                                           

  IIB GEO AND                                                        
  BEYOND (Earth                                                      
  Orbiting)                                                          
  -------------------------------------------------------------------------------

**APPENDIX B**

**ACRONYMS AND ABBREVIATIONS**

**Appendix B**

**ACRONYMS and ABBREVIATIONS**

14^th^ AF Fourteenth Air Force

3-d three dimensions

A~o~ Operational Availability

Acq Acquisition

ADT Architecture Development Team

AFSCN Air Force Satellite Control Network

AFSPC Air Force Space Command

AJ Antijam

AIS Automated Information Systems

AMP Acquisition Master Plan

AOR Area of Responsibility

Arch Architecture

ASAT Anti-Satellite

ATC Air Traffic Control

BDA Battle Damage Assessment

C/A Coarse Acquisition

C-SCAN Carrier System for Controlled Approach of Naval Aircraft

C2 Command and Control

C4I Command, Control, Communications, Computers, and Intelligence

CJCS Chairman, Joint Chiefs of Staff

CJCSI Chairman, Joint Chiefs of Staff Instruction

cm Centimeter

CONOPS Concept of Operations

CONUS Continental United States

COS Continuity of Service

CRD Capstone Requirements Document

D~o~ Operational Dependability

DGPS Differential Global Positioning System

DIA Defense Intelligence Agency

DME Distance Measuring Equipment

DOC Department of Commerce

DoD Department of Defense

DOT Department of Transportation

DPG Defense Planning Guidance

DPS

DRMS Distance Root Mean Square

DSMAC Digital Scene Matching Area Correlation

EGNOS European Geostationary Navigation Overlay Service

el Elevation

EMP Electromagnetic Pulse

EPA Environmental Protection Agency

EW Electronic Warfare

FAA Federal Aviation Administration

FDE Fault Detection and Exclusion

FL Flight Level

FRP Federal Radionavigation Plan

FOC Full Operational Capability

FY Fiscal Year

GA Ground Antenna

GANS Global Access, Navigation, and Safety

GATM Global Air Traffic Management

GCA Ground Controlled Approach

GCCS Global Command and Control System

GCSS Global Command Support System

GIS Geographic Information System

GEO Geosynchronous Earth Orbit

GLONASS Global Navigation Satellite System

GPS Global Positioning System

GZ Ground Zero

HEO Highly Elliptical Orbit

HMI Hazardously Misleading Information

ICAO International Civil Air Organization

IGEB Interagency GPS Executive Board

ILS Instrument Landing System

IMO International Maritime Organization

INS Inertial Navigation System

ISS International Space Station

IVHS Intelligent Vehicle Highway System

IW Information Warfare

JCAB Japan Civil Aviation Bureau

JPALS Joint Precision Approach and Landing System

JPL Jet Propulsion Laboratory

JROC Joint Requirements Oversight Council

JTIDS Joint Tactical Information Distribution System

Km Kilometer

KPP Key Performance Parameter

LAAS Local Area Augmentation System

LEO Low Earth Orbit

LORAN Long Range Navigation

m Meter

mm Millimeter

MAP Mission Area Plan

MATCALS Marine Air Traffic Control and Landing System

Mgt Management

MHz Megahertz

MIJI Meaconing, Interference, Jamming, and Intrusion

MLS Microwave Landing System

MNP Master Navigation Plan

MNS Mission Need Statement

MRAALS Marine Remote Area Approach and Landing System

MTSAT Multi-function Transport Satellite

MTW Major Theater War

NAIC National Air Intelligence Center

NAS National Airspace System

NASA National Aeronautics and Space Administration

NAVAIDS Navigation Aids

NDB Nondirectional Beacons

NIPRNET Non-Secure Internet Protocol Router Network

NM Nautical Mile

NRT Near-Real-Time

nsec Nanosecond

NSTC National Science and Technology Council

NUDET Nuclear Detection

Obj Objective

Ops Operations

ORD Operational Requirements Document

OTH Over-the-Horizon

PADS Position Azimuth Determining System

PALS Precision Approach Landing System

PAR Precision Approach Radar

PDD Presidential Decision Directive

POM Program Objective Memorandum

POS/NAV Positioning and Navigation

PP Post Processing

PPBS Planning, Programming, and Budgeting System

PPS Precise Positioning System

PVT Positioning, Velocity, and Time

RAIM Receiver Autonomous Integrity Monitoring

RF Radio Frequency

RNP Required Navigation Performance

Rqmts Requirements

RTK Real-Time Kinematics

SA Selective Availability

SATNAV Satellite Navigation

SATOPS Satellite Operations

sec Second

SEP Spherical Error Probable

SIAGL Survey Instrument Azimuth Gyroscope Lightweight

SIGINT Signals Intelligence

SIPRNET Secure Internet Protocol Router Network

SIS Signals in Space

SMC Space and Missile Systems Center

SPS Standard Positioning Service

SRP/PDS Stabilization Reference Package/Position Determining System

SSC Small Scale Contingency

STAR System Threat Assessment Report

SV Space Vehicle

TACAN Tactical Air Navigation

TBP To Be Provided

TERCOM Terrain Contour Matching

TOPEX/POSEIDON TOPographic EXperiment/POSEIDON

UE User Equipment

US United States

USAF United States Air Force

USC United States Code

USCG United States Coast Guard

USG US Government

USNO United States Naval Observatory

USSPACECOM United States Space Command

UTC Coordinated Universal Time

UTC (USNO) UTC as maintained at the USNO

VHF Very High Frequency

VOR/DME Very High Frequency Omnidirectional Range/Distance Measuring
Equipment

VTS Vessel Traffic Service

WAAS Wide Area Augmentation System

WGS World Geodetic Survey

**APPENDIX C**

**GLOSSARY**

**Appendix C**

**GLOSSARY**

Air Traffic Control (ATC) - A service operated by appropriate authority
to promote the safe, orderly, and expeditious flow of air traffic.

Approach Reference Datum - A point at a specified height above the
runway centerline and the threshold. The height of the MLS approach
reference datum is 15 meters (50 ft). A tolerance of plus 3 meters (10
ft) is permitted.

Area Navigation (RNAV) - Application of the navigation process providing
the capability to establish and maintain a flight path on any
arbitrarily chosen course that remains within the coverage area of
navigation sources being used.

Automatic Dependent Surveillance - A function in which aircraft
automatically transmit navigation data derived from onboard navigation
systems via a datalink for use by air traffic control.

Block II/IIA - The satellites that form the initial GPS constellation at
FOC.

Cellular Triangulation - A method of location determination using the
cellular phone system where the control channel signals from a mobile
phone are captured by two or more fixed base stations and processed
according to an algorithm to determine the location of the mobile
receiver.

Circular Error Probable (CEP) - In a circular normal distribution (the
magnitudes of the two one-dimensional input errors are equal and the
angle of cut is 90 o ), circular error probable is the radius of the
circle containing 50 percent of the individual measurements being made,
or the radius of the circle inside of which there is a 50 percent
probability of being located.

Coastal Confluence Zone (CCZ) - Harbor entrance to 50 nautical miles
offshore or the edge of the continental shelf (100 fathom curve),
whichever is greater.

Common-use Systems - Systems used by both civil and military sectors.

Conterminous US - Forty-eight adjoining states and the District of
Columbia.

Coordinate Conversion - The act of changing the coordinate values from
one system to another; e.g., from geodetic coordinates (latitude and
longitude) to Universal Transverse Mercator grid coordinates.

Coordinated Universal Time (UTC) - UTC, an atomic time scale, is the
basis for civil and DoD time. It is occasionally adjusted by one-second
increments to ensure that the difference between the uniform time scale,
defined by atomic clocks, does not differ from the earth's rotation by
more than 0.9 seconds. UTC (USNO) is the real-time realization of UTC
for the purpose of UTC dissemination by the GPS.

Differential - A technique used to improve radionavigation system
accuracy by determining positioning error at a known location and
subsequently transmitting the determined error, or corrective factors,
to users of the same radionavigation system, operating in the same area.

Distance Root Mean Square (drms) - The root-mean-square value of the
distances from the true location point of the position fixes in a
collection of measurements. As used in this document, 2 drms is the
radius of a circle that contains at least 95 percent of all possible
fixes that can be obtained with a system at any one place. Actually, the
percentage of fixes contained within 2 drms varies between approximately
95.5 percent and 98.2 percent, depending on the degree of ellipticity of
the error distribution.

En Route - A phase of navigation covering operations between a point of
departure and termination of a mission. For airborne missions the en
route phase of navigation has two subcategories, en route domestic and
en route oceanic.

En Route Domestic - The phase of flight between departure and arrival
terminal phases, with departure and arrival points within the
conterminous United States.

En Route Oceanic - The phase of flight between the departure and arrival
terminal phases, with an extended flight path over an ocean.

Flight Technical Error (FTE) - The contribution of the pilot in using
the presented information to control aircraft position.

Full Operational Capability (FOC) - For GPS, this is defined as the
capability that will occur when 24 operational (Block II/IIA) satellites
are operating in their assigned orbits and have been tested for military
functionality and meet military requirements.

Geocentric - Relative to the Earth as a center, measured from the center
of mass of the Earth.

Geodesy - The science related to the determination of the size and shape
of the Earth (geoid) by such direct measurements as triangulation,
leveling, and gravimetric observations; which determines the external
gravitational field of the Earth and, to a limited degree, the internal
structure.

Geometric Dilution Of Precision (GDOP) - All geometric factors that
degrade the accuracy of position fixes derived from
externally-referenced navigation systems.

Inclination - One of the orbital elements (parameters) that specifies
the orientation of an orbit. Inclination is the angle between the
orbital plane and a reference plane, the plane of the celestial equator
for geocentric orbits and the ecliptic for heliocentric orbits.

Initial Operational Capability (IOC) - For GPS, this is defined as the
capability that will occur when 24 GPS satellites (Block I/II/IIA) are
operating in their assigned orbits and are available for navigation use.

Multipath Transmission - The propagation phenomenon that results in
signals reaching the receiving antenna by two or more paths. When two or
more signals arrive simultaneously, wave interference results. The
received signal fades if the wave interference is time varying or if one
of the terminals is in motion.

Meaconing - A technique of manipulating radio frequency signals to
provide false navigation information.

Nanosecond (ns) - One billionth of a second.

National Airspace System (NAS) - The NAS includes US airspace; air
navigation facilities, equipment and services; airports or landing
areas; aeronautical charts, information and service; rules, regulations
and procedures; technical information; and labor and material used to
control and/or manage flight activities in airspace under the
jurisdiction of the US System components shared jointly with the
military are included.

National Command Authority (NCA) - The NCA is the President or the
Secretary of Defense, with the approval of the President. The term NCA
is used to signify constitutional authority to direct the Armed Forces
in their execution of military action. Both movement of troops and
execution of military action must be directed by the NCA; by law, no one
else in the chain of command has the authority to take such action.

Nautical Mile (nm) - A unit of distance used principally in navigation.
The International Nautical Mile is 1,852 meters long.

Navigation - The process of planning, recording, and controlling the
movement of a craft or vehicle from one place to another.

Nonprecision Approach - A standard instrument approach procedure in
which no electronic glide slope is provided (e.g., VOR, TACAN, Loran-C,
or NDB).

Primary Means of Navigation - Identifies navigation equipment which
provides the only required means on an aircraft of satisfying the
necessary level of accuracy, integrity, and availability for a
particular area, route, procedure, or operation. The failure of a
primary means of navigation requires reversion to a non-normal means of
navigation (e.g., dead reckoning).

Precise Time - A time not to exceed a range which is defined by user
requirements.

Precision Approach - A standard instrument approach procedure using a
ground-based system in which an electronic glide slope is provided
(e.g., ILS).

Primary-means Navigation System - Meets accuracy and integrity
requirements, but does not meet full availability and continuity
requirements.

Pseudolite - Ground-based transmitters that can be configured to emit
GPS-like signals for enhancing the GPS by providing increased accuracy,
integrity, and availability.

Radiodetermination - The determination of position, or the obtaining of
information relating to positions, by means of the propagation
properties of radio waves.

Radiolocation - Radiodetermination used for purposes other than those of
radionavigation.

Radionavigation - The determination of position, or the obtaining of
information relating to position, for the purposes of navigation by
means of the propagation properties of radio waves.

Receiver Autonomous Integrity Monitoring (RAIM) - A technique whereby a
civil GPS receiver/processor determines the integrity of the GPS
navigation signals without reference to sensors or non-DoD integrity
systems other than the receiver itself. This determination is achieved
by a consistency check among redundant pseudorange measurements.

Reliability - The probability of performing a specified function without
failure under given conditions for a specified period of time.

Required Navigation Performance - A statement of the navigation
performance accuracy necessary for operation within a defined airspace,
including the operating parameters of the navigation systems used within
that airspace.

RHO (Ranging Mode) - A mode of operation of a radionavigation system in
which the times for the radio signals to travel from each transmitting
station to the receiver are measured rather than their differences (as
in the hyperbolic mode).

Roadside Beacons - A system using infrared or radio waves to communicate
between transceivers placed at roadsides and the in-vehicle transceivers
for navigation and route guidance functions.

Sigma - See Standard Deviation.

Sole-means Navigation System - Meets accuracy, integrity, availability,
and continuity requirements.

Spherical Error Probable (SEP) - The radius of a sphere within which
there is a 50 percent probability of locating a point or being located.
SEP is the three-dimensional analogue of CEP.

Standard Deviation (sigma) - A measure of the dispersion of random
errors about the mean value. If a large number of measurements or
observations of the same quantity are made, the standard deviation is
the square root of the sum of the squares of deviations from the mean
value divided by the number of observations less one. Averaged, the
standard deviation of their average is less than the standard deviation
of any one observation, but can never be less than the systematic errors
common to all observations

Supplemental Air Navigation System - An approved navigation system that
can be used in controlled airspace of the National Airspace System in
conjunction with a primary means of navigation.

Supplemental-means of Navigation - Meets accuracy and integrity
requirements for a given phase of flight. Does not meet availability and
continuity requirements. Must be used in conjunction with a sole-means
system.

Surveillance - The observation of an area or space for the purpose of
determining the position and movements of craft or vehicles in that area
or space.

Survey - The act of making measurements to determine the relative
position of points on, above, or beneath the Earth's surface.

Surveying - That branch of applied mathematics which teaches the art of
determining accurately the area of any part of the Earth's surface, the
lengths and directions of the bounding lines, the contour of the
surface, etc., and accurately delineating the whole on a map or chart
for a specified datum.

Terminal - A phase of navigation covering operations required to
initiate or terminate a planned mission or function at appropriate
facilities. For airborne missions, the terminal phase is used to
describe airspace in which approach control service or airport traffic
control service is provided.

Terminal Area - A general term used to describe airspace in which
approach control service or airport traffic control service is provided.

Theta - Bearing or direction to a fixed point to define a line of
position.

Time Interval - The duration of a segment of time without reference to
where the time interval begins or ends.

TOPEX/POSEIDON - TOPographic EXperiment/POSEIDON mission, a joint
US/French oceanic mapping mission launched in August 1992.

Universal Transverse Mercator (UTM) Grid - A military grid system based
on the Transverse Mercator projection applied to maps of the Earth's
surface extending to 84 degrees N and 80 degrees S latitudes.

Vehicle Location Monitoring - A service provided to maintain the orderly
and safe movement of platforms or vehicles. It encompasses the
systematic observation of airspace, surface and subsurface areas by
electronic, visual or other means to locate, identify, and control the
movement of platforms or vehicles.

World Geodetic System (WGS) - A consistent set of parameters describing
the size and shape of the Earth, the positions of a network of points
with respect to the center of mass of the Earth, transformations from
major geodetic datums, and the potential of the Earth (usually in terms
of harmonic coefficients).

**APPENDIX D**

**REFERENCES**

**Appendix D**

**REFERENCES**

1.  CSAF/CV Message, 281504Z January 1997, Subject: Global Positioning
    System Capstone Requirements Document

2.  [AF Navigation and Safety Master Plan, 26 Aug 96]{.underline}.

3.  [Example of an RMA Enabling Technology with
    Implications]{.underline}, Earl W. Rubright, 27 Mar 97.

4.  US Navy Operational Requirements Document for GPS User Equipment,
    Undated (DRAFT)

5.  US Navy MNS for Protection and Prevention of Space-Based Global
    Navigation Systems, 12 March 96

6.  Joint USAF-USN MNS for Precision Approach and Landing Capability, 9
    August 1994.

7.  Under Secretary of Defense and the Vice Chairman, Joint Chiefs of
    Staff Memorandum of 6 June 1996.

    Directed actions which are intended to "enable DoD aircraft to take
    off, fly and recover to non-precision approach minima anywhere in
    the world without reference to ground-based radionavigation aids."

8.  Capstone Requirements Document 001-97, Global Air Traffic
    Management, HQ AMC/XPQN, (Draft), Revision 1, 12 May 1997

9.  AMC MNS 001-92, Data Link Capability, 28 Jun 93

10. Air Force Space Command Mission Need Statement 003-92 for Improved
    Worldwide Navigational Positioning System, AFSPACECOM/DRFN, 29
    January 1993

11. AFSPACECOM (USAF 003-78) I/II/III SORD, Navstar Global Positioning
    System (GPS), AFSPACECOM/XPSS, 22 Jan 90.

12. Air Force Space Command Operational Requirements Document
    003-92-III, Worldwide Navigational Positioning System, HQ AFSPC/DR,
    21 March 1997 (Draft).

13. Chairman, Joint Chiefs of Staff Instruction 6130.01, CJCS Master
    Navigation Plan, 20 May 1994

14. White House Commission on Aviation Safety and Security, Final Report
    to President Clinton, February 12, 1997

15. Concept of Operations for the NAVSTAR Global Positioning System
    (GPS), HQ AFSPC/DOXC, June 1996

16. Annex A to the Concept of Operations for Air Force Satellite
    Control, "Backup Operations," HQ AFSPC/DOXC, Undated

17. Systems Operation Concept Description For The Block IIF NAVSTAR
    Global Positioning System, prepared for the Space and Missile
    Systems Center, 1 February 1997 (Draft)

18. Air Force Modernization Planning, Space Information Dominance
    Mission Area Plan, HQ AFSPC/XPX, 17 December 1996

19. 1994 Federal Radionavigation Plan, Eighth Edition, Department of
    Defense (USD/A&T) and Department of Transportation (OST/P), May 1995

20. ACC ORD 003-95-I/II, Operational Protection and Prevention of Global
    Space-Based Navigation Systems Navigation Warfare (NAVWAR), undated
    (Draft).

21. AMC MNS 004-93, Intraformation Positioning/Collision Avoidance
    Capability, 23 Nov 93

22. AMC MNS 007-93, Reduced Vertical Separation Minima (RVSM)
    Capability, 8 Jan 94.

23. A Technical Report to the Secretary of Transportation on a National
    Approach to Augmented GPS Service, December, 1994.

24. Joint US Department of Defense/US Department of Transportation Task
    Force, *The Global Positioning System: Management and Operation of a
    Dual Use System*, Washington, DC, December 1993 (Added)

25. DoD Memorandum to National Academy of Public Administration from
    DUSD (Space), 10 April 1995, Re: Draft Study on GPS.

26. DoD Memorandum to Dr James Schlesinger from USD (A&T), 22 May 1995,
    Re: NAPA and NAS GPS Study.

27. Navstar Global Positioning System (GPS), System Threat Assessment
    Report (STAR) (U), NAIC-1574-0407-97, March 1997

28. The Space Systems Threat Environment Description, (SECRET), dated 11
    September 1995, produced by the National Air Intelligence Center
    (NAIC)

29. Space Information Dominance Mission Area Plan, HQ AFSPC/XPX, 17
    December 1996

30. Operational Requirements Document I (ORD) Joint Precision Approach
    Landing System ACAT Level ID, 15 Oct 96

31. 1996 Federal Radionavigation Plan (draft), Ninth Edition, Department
    of Defense (USD/A&T) and Department of Transportation (OST/P)

32. Headquarters Air Combat Command ORD for GPS Navigation Warfare User
    Requirements (Draft), May 1996

33. [ESA In Brief]{.underline}, European Space Agency Bulletin Nr. 87,
    August 1996

34. Global Positioning and Navigation News

35. US Army Signal Center ORD for the GPS Tactical Receiver, 24 Mar 1997

36. FAA ORD for Local Area Augmentation System, Change 1, 7 December
    1995

37. Air Mobility Command MNS for Required Navigation Performance (AMC
    003-97) (Draft), Undated

38. Department of Defense Directive 4650.5, Positioning and Navigation
    Systems Administration and Planning, 5 Dec 1990

39. Chairman, Joint Chiefs of Staff Instruction 6130.01, 1997 CJCS
    Master Navigation Plan, (Draft)

40. USSPACECOM MNS 003-95, Operational Protection and Prevention of
    Global Space-Based Navigation Systems (U), Sep 95

41. AFSPC Operational Requirements Document for Global Positioning
    System Jammer, (Draft)

42. Duffet-Smith, P. \`\`Time.\'\' Practical Astronomy with Your
    Calculator, 3rd ed. Cambridge, England: Cambridge University Press,
    pp. 1-23, 1992.

43. [New World Vistas]{.underline}, Space Applications Volume, Science
    Advisory Board, December, 1995.

44. DOT Requirements Survey in Support of the PVT CRD, March 1997 and
    Continuing

45. SMC/CZ GPS Modernization Briefing, 24 June 1997Briefing

46. [The "Global Positioning System, Charting the Future"
    Study]{.underline}. May 1995, published by the National Academy of
    Public Administration and the National Research Council.

47. Universal Joint Task List, Version 3.0, CJCSM 3500.04A, 13
    September, 1996.

48. Joint Vision 2010, Office of the Joint Chiefs of Staff, 1997.

49. The Global Positioning System, A Shared National Asset, National
    Research Council, 1995

50. DoD Directive 4650.5, Positioning and Navigation Systems
    Administration and Planning, December 5, 1990

51. [Air Combat Command MNS 003-95 for Operational Protection and
    Prevention of Global Space-based Navigation Systems]{.underline}, 27
    Sep 1995

**APPENDIX E**

**OTHER PVT SYSTEMS**

**Appendix E**

**Other PvT Systems**

This appendix is a supplement to Section 3. It summarizes the
capabilities of special-purpose PVT systems that were developed (or are
under development) for specific purposes. Their development and fielding
is not intended to satisfy the general military and civil need for PVT
services documented in Section 4 and Appendix A of this CRD. This
appendix is limited to a tabular summary (Table E-1) of system
capabilities and characteristics. For more detail on these systems refer
to the CJCS Master Navigation Plan and the Federal Radionavigation Plan.

**Table E-1. Other PVT Systems**

+------------+-------+-------+-------+-------+-------+-------+-------+
|            |       |       |       |       | **Sta |       |       |
|            |       |       |       |       | tus** |       |       |
+============+=======+=======+=======+=======+=======+=======+=======+
| **System** | *     | **    | **    | *     | **    | **Ci  | **    |
|            | *Serv | Cover | Accur | *Avai | DoD** | vil** | Opera |
|            | ice** | age** | acy** | labil |       |       | tor** |
|            |       |       |       | ity** |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Air        | Commu |       |       |       | HQ    |       | Mil   |
| Traffic    | nicat |       |       |       | USAF  |       | itary |
| Control    | ions, |       |       |       | MNS   |       | Ser   |
| and        | N     |       |       |       | 0     |       | vices |
| Landing    | aviga |       |       |       | 01-96 |       |       |
| Systems    | tion, |       |       |       |       |       |       |
|            | Su    |       |       |       |       |       |       |
|            | rveil |       |       |       |       |       |       |
|            | lance |       |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Air        | Ident | LOS   | ± 300 |       | O     |       | Mil   |
| Traffic    | ifica | (\<   | m     |       | perat |       | itary |
| Control    | tion, | 250   | range |       | ional |       | Ser   |
| Radar      | P     | nm)   |       |       |       |       | vices |
| Beacon     | ositi |       | ±     |       |       |       |       |
| System     | oning |       | 1.6   |       |       |       |       |
|            | (Alti |       | -5.6° |       |       |       |       |
|            | tude) |       | be    |       |       |       |       |
|            |       |       | aring |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Air        | P     | Depe  | R     |       | O     |       | Mil   |
| Traffic    | ositi | ndent | ange: |       | perat |       | itary |
| Control    | oning | on    | ± 150 |       | ional |       | Ser   |
| Radar      |       | alt   | m,    |       |       |       | vices |
|            |       | itude |       |       |       |       |       |
|            |       |       | Bea   |       |       |       |       |
|            |       |       | ring: |       |       |       |       |
|            |       |       | ±     |       |       |       |       |
|            |       |       | 1.2°  |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Bottom     | P     |       | ± 200 |       | O     |       | US    |
| Contour    | ositi |       | m     |       | perat |       | Navy  |
| Navigation | oning |       | (with |       | ional |       |       |
|            | (from |       | acc   |       |       |       |       |
|            | sea   |       | urate |       |       |       |       |
|            | bo    |       | ch    |       |       |       |       |
|            | ttom) |       | arts) |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Carrier    | P     | R     | Rela  |       | O     |       | US    |
| Systems    | ositi | ange: | tive: |       | perat |       | Navy  |
| for        | oning | 19 km |       |       | ional |       |       |
| Controlled |       |       | ±     |       |       |       |       |
| Approach   |       | Azi   | 0.2°  |       |       |       |       |
| of Naval   |       | muth: | az    |       |       |       |       |
| Aircraft   |       | +20°  | imuth |       |       |       |       |
|            |       |       |       |       |       |       |       |
|            |       | Eleva | ±     |       |       |       |       |
|            |       | tion: | 0.1°  |       |       |       |       |
|            |       | 0-10° | elev  |       |       |       |       |
|            |       |       | ation |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Celestial  | P     | G     | Av    |       | O     | O     | Mil   |
| Navigation | ositi | lobal | erage |       | perat | perat | itary |
|            | oning |       | e     |       | ional | ional | Serv  |
|            |       |       | rror: |       |       |       | ices, |
|            |       |       |       |       |       |       | Civil |
|            |       |       | 2 nm, |       |       |       | users |
|            |       |       | 3 -   |       |       |       |       |
|            |       |       | 30 m  |       |       |       |       |
|            |       |       | with  |       |       |       |       |
|            |       |       | autom |       |       |       |       |
|            |       |       | ation |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Co         | P     | Natio | Pre   |       |       | 75    | Nat   |
| ntinuously | ositi | nwide | cise, |       |       | sta   | ional |
| Operating  | oning |       | rel   |       |       | tions | Geo   |
| Reference  | (post |       | ative |       |       | as of | detic |
| Station    | p     |       | to    |       |       | Sep   | S     |
|            | roces |       | NAD   |       |       | 96    | urvey |
|            | sing) |       | 83    |       |       | (many | (     |
|            |       |       |       |       |       | are   | DGPS, |
|            |       |       |       |       |       | dual  | WAAS, |
|            |       |       |       |       |       | use)  | NOAA) |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Di         | Po    | TBD   | Si    |       | JPALS |       | Mil   |
| fferential | sitio |       | milar |       | a     |       | itary |
| GPS        | ning, |       | to    |       | cquis |       | Ser   |
|            | Velo  |       | WAAS  |       | ition |       | vices |
|            | city, |       | /LAAS |       |       |       |       |
|            | T     |       |       |       |       |       |       |
|            | iming |       |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Digital    | P     | Pri   | 1 sq  |       | Ac    | See   | Mil   |
| Airport    | ositi | mary: | m     |       | quisi | DoD   | itary |
| Su         | oning | 60 nm | t     |       | tion, |       | Serv  |
| rveillance |       | rad   | aget: |       | joint |       | ices, |
| Radar      |       | to    | Azi   |       | DoD   |       | FAA   |
|            |       | 24K   | muth: |       | and   |       |       |
|            |       | ft    | 0.16° |       | FAA   |       |       |
|            |       | AGL;  | rms,  |       |       |       |       |
|            |       | Secon | R     |       |       |       |       |
|            |       | dary: | ange: |       |       |       |       |
|            |       | 120   | .125  |       |       |       |       |
|            |       | nm to | nm at |       |       |       |       |
|            |       | 60K   | .80   |       |       |       |       |
|            |       | ft    | Pd    |       |       |       |       |
|            |       | AGL   |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Direction  | P     | Line  | Rela  | 99%   | O     |       | Mill  |
| Finding    | ositi | of    | tive: |       | perat |       | itary |
|            | oning | sight |       |       | ional |       | Ser   |
|            | (Bea  | from  | ± 3   |       |       |       | vices |
|            | ring) | t     | to 5° |       |       |       |       |
|            |       | ransm |       |       |       |       |       |
|            |       | itter |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Doppler    | Po    | G     | 0.1   |       | O     |       | Mil   |
|            | sitio | lobal | to    |       | perat |       | itary |
|            | ning, |       | 0.3%  |       | ional |       | Ser   |
|            | Vel   |       |       |       |       |       | vices |
|            | ocity |       |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Digital    | P     | T     |       |       | O     |       | US    |
| Scene      | ositi | arget |       |       | perat |       | Navy  |
| Matching   | oning | area  |       |       | ional |       |       |
| Area       | (mi   |       |       |       |       |       |       |
| C          | ssile |       |       |       |       |       |       |
| orrelation | guid  |       |       |       |       |       |       |
|            | ance) |       |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Joint      | P     | Tac   | 75 m  |       | O     |       | Mil   |
| Tactical   | ositi | tical |       |       | perat |       | itary |
| I          | oning | th    |       |       | ional |       | Ser   |
| nformation |       | eater |       |       |       |       | vices |
| Di         |       |       |       |       |       |       |       |
| stribution |       |       |       |       |       |       |       |
| System     |       |       |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Marine Air | P     | Azi   | Azi   |       | O     |       | US    |
| Traffic    | ositi | muth: | muth: |       | perat |       | M     |
| and        | oning | ± 23° | ± 3 m |       | ional |       | arine |
| Landing    |       | Eleva |       |       |       |       | Corps |
| System     |       | tion: | Eleva |       |       |       |       |
|            |       | -1°   | tion: |       |       |       |       |
|            |       | to    | ± 2 m |       |       |       |       |
|            |       | +7°   |       |       |       |       |       |
|            |       |       | (at 1 |       |       |       |       |
|            |       |       | km)   |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Marine     | P     | Dist  | Az: ± |       | O     |       | US    |
| Remote     | ositi | ance: | 1.74  |       | perat |       | M     |
| Area       | oning | 18.5  | m     |       | ional |       | arine |
| Approach   |       | km    |       |       |       |       | Corps |
| and        |       |       | El:   |       |       |       |       |
| Landing    |       | Azi   | 0.87  |       |       |       |       |
| System     |       | muth: | m     |       |       |       |       |
|            |       | ± 20° |       |       |       |       |       |
|            |       |       | R     |       |       |       |       |
|            |       | Eleva | ange: |       |       |       |       |
|            |       | tion: | ± 70  |       |       |       |       |
|            |       | 0 -   | m     |       |       |       |       |
|            |       | 20°   |       |       |       |       |       |
|            |       |       | at 1  |       |       |       |       |
|            |       |       | km    |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Maritime   | Po    | US    | 10    | 99.9% |       | Op    | US    |
| Di         | sitio | C     | m     | in    |       | erati | Coast |
| fferential | ning, | oasts | eters | sel   |       | onal, | Guard |
| GPS        | Velo  | to 20 | or    | ected |       | Ra    |       |
|            | city, | nm    | less  | wate  |       | pidly |       |
|            | T     | from  | (2    | rways |       | incre |       |
|            | iming | s     | drms) | and   |       | asing |       |
|            |       | hore, |       | 99.7% |       | use   |       |
|            |       | Ha    |       | in    |       |       |       |
|            |       | waii, |       | other |       |       |       |
|            |       | co    |       | areas |       |       |       |
|            |       | astal |       |       |       |       |       |
|            |       | Al    |       |       |       |       |       |
|            |       | aska, |       |       |       |       |       |
|            |       | P     |       |       |       |       |       |
|            |       | uerto |       |       |       |       |       |
|            |       | Rico, |       |       |       |       |       |
|            |       | major |       |       |       |       |       |
|            |       | US    |       |       |       |       |       |
|            |       | r     |       |       |       |       |       |
|            |       | ivers |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Mobile     |       |       |       | 37    | O     |       | US    |
| Microwave  |       |       |       | m     | perat |       | Air   |
| Landing    |       |       |       | obile | ional |       | Force |
| System     |       |       |       | sets  |       |       |       |
|            |       |       |       | for   |       |       |       |
|            |       |       |       | c     |       |       |       |
|            |       |       |       | ontin |       |       |       |
|            |       |       |       | gency |       |       |       |
|            |       |       |       | opera |       |       |       |
|            |       |       |       | tions |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| National   | T     | B     | W     |       |       | Ope   | NIST  |
| Institute  | iming | eyond | ithin |       |       | ratio |       |
| of         |       | line  | 1     |       |       | nal - |       |
| Standards  |       | of    | μsec  |       |       | sta   |       |
| and        |       | sight | of    |       |       | tions |       |
| Technology |       | of    | USNO  |       |       | at    |       |
| (WWV,      |       | stat  | M     |       |       | Bo    |       |
| WWVH)      |       | ions, | aster |       |       | ulder |       |
|            |       | de    | C     |       |       | CO    |       |
|            |       | pends | lock; |       |       | and   |       |
|            |       | on    | BLOS  |       |       | H     |       |
|            |       | p     | is 1  |       |       | awaii |       |
|            |       | ropag | msec  |       |       |       |       |
|            |       | ation | (     |       |       |       |       |
|            |       |       | corre |       |       |       |       |
|            |       |       | cted) |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| North      | P     | Worl  | Az    |       | O     |       | US    |
| Seeking    | ositi | dwide | e     |       | perat |       | Army  |
| Gyroscope  | oning | from  | rror: |       | ional |       |       |
|            |       | 0-75° | 8.5   |       |       |       |       |
|            |       | lat   | mils  |       |       |       |       |
|            |       | itude |       |       |       |       |       |
|            |       |       | Ver   |       |       |       |       |
|            |       |       | tical |       |       |       |       |
|            |       |       | angle |       |       |       |       |
|            |       |       | e     |       |       |       |       |
|            |       |       | rror: |       |       |       |       |
|            |       |       | 3.5   |       |       |       |       |
|            |       |       | mils  |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Position   | P     | Div   | Horz: |       | A     |       | US    |
| Location   | ositi | ision | 25-30 |       | cquis |       | Army  |
| Reporting  | oning | tac   | m     |       | ition |       |       |
| System     |       | tical |       |       |       |       | US    |
|            |       | area, | Ver   |       |       |       | M     |
|            |       | 100   | tical |       |       |       | arine |
|            |       | nm    | e     |       |       |       | Corps |
|            |       | for   | rror: |       |       |       |       |
|            |       | air   | 3% of |       |       |       |       |
|            |       | craft | pla   |       |       |       |       |
|            |       |       | tform |       |       |       |       |
|            |       |       | alt.  |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Precision  | P     | Dist  | Az    |       | O     |       | US    |
| Approach   | ositi | ance: | imuth |       | perat |       | Navy  |
| and        | oning | 15 km | &     |       | ional |       |       |
| Landing    |       |       | eleva |       |       |       |       |
| System     |       | Azi   | tion: |       |       |       |       |
|            |       | muth: |       |       |       |       |       |
|            |       | ± 55° | ±     |       |       |       |       |
|            |       |       | 0     |       |       |       |       |
|            |       | Eleva | .044° |       |       |       |       |
|            |       | tion: |       |       |       |       |       |
|            |       | -15   |       |       |       |       |       |
|            |       | to    |       |       |       |       |       |
|            |       | +30°  |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Polarfix   | P     | 5 km  | ± 0.5 |       | O     |       | US    |
|            | ositi |       | m ±   |       | perat |       | Navy, |
|            | oning |       | 0.1 % |       | ional |       |       |
|            |       |       | of    |       |       |       | US    |
|            |       |       | mea   |       |       |       | Army  |
|            |       |       | sured |       |       |       |       |
|            |       |       | dist. |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Position   | P     | 7 hr  | Hor:  | Re    | O     |       | US    |
| and        | ositi | or 55 | 4 m   | liabi | perat |       | Army  |
| Azimuth    | oning | km    | CEP   | lity: | ional |       |       |
| D          |       | mi    |       |       |       |       |       |
| etermining |       | ssion | Vert: | 500   |       |       |       |
| System     |       | dur   | 2 m   | to    |       |       |       |
|            |       | ation | PE    | 1000  |       |       |       |
|            |       |       |       | hours |       |       |       |
|            |       |       | 0.4   | MTBF  |       |       |       |
|            |       |       | mil   |       |       |       |       |
|            |       |       | (PE)  |       |       |       |       |
|            |       |       | d     |       |       |       |       |
|            |       |       | irect |       |       |       |       |
|            |       |       | ional |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Precision  | Multi |       |       |       | JPALS |       | Mil   |
| Landing    | -mode |       |       |       | a     |       | itary |
| System     | rec   |       |       |       | cquis |       | Ser   |
| Receiver   | eiver |       |       |       | ition |       | vices |
|            | (ILS, |       |       |       |       |       |       |
|            | MLS,  |       |       |       |       |       |       |
|            | DGPS) |       |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Survey     | P     | Worl  | ±     |       | O     |       | US    |
| I          | ositi | dwide | 0.15  |       | perat |       | Army  |
| nstrument, | oning | (from | mils  |       | ional |       |       |
| Azimuth    |       | 0 to  | di    |       |       |       |       |
| Gyro,      |       | 75°   | vided |       |       |       |       |
| L          |       | lati  | by    |       |       |       |       |
| ightweight |       | tude) | c     |       |       |       |       |
|            |       |       | osine |       |       |       |       |
|            |       |       | of    |       |       |       |       |
|            |       |       | lat   |       |       |       |       |
|            |       |       | itude |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Sta        | P     |       |       |       | O     |       | Mil   |
| bilization | ositi |       |       |       | perat |       | itary |
| Reference  | oning |       |       |       | ional |       | Ser   |
| Package/   | (     |       |       |       |       |       | vices |
| Position   | direc |       |       |       |       |       |       |
| D          | tion, |       |       |       |       |       |       |
| etermining | eleva |       |       |       |       |       |       |
| System     | tion, |       |       |       |       |       |       |
|            | cant) |       |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Terrain    | P     | Sp    |       |       | O     |       | Mil   |
| Contour    | ositi | ecifi |       |       | perat |       | itary |
| Matching   | oning | cally |       |       | ional |       | Ser   |
|            |       | digi- |       |       |       |       | vices |
|            |       | tized |       |       |       |       |       |
|            |       | land  |       |       |       |       |       |
|            |       | areas |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Vessel     | P     | 0-24  | R     |       |       | O     | US    |
| Traffic    | ositi | nm    | ange: |       |       | perat | Coast |
| Services   | oning | from  | ± 20  |       |       | ional | Guard |
|            |       | an    | yds   |       |       |       |       |
|            |       | tenna |       |       |       |       |       |
|            |       |       | Bea   |       |       |       |       |
|            |       |       | ring: |       |       |       |       |
|            |       |       | ±     |       |       |       |       |
|            |       |       | 1.25° |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+
| Other      |       |       |       |       |       |       |       |
| S          |       |       |       |       |       |       |       |
| pecial-use |       |       |       |       |       |       |       |
| Systems:   |       |       |       |       |       |       |       |
| Doppler    |       |       |       |       |       |       |       |
| Log,       |       |       |       |       |       |       |       |
| Advanced   |       |       |       |       |       |       |       |
| HF         |       |       |       |       |       |       |       |
| Submarine  |       |       |       |       |       |       |       |
| SONAR,     |       |       |       |       |       |       |       |
| Precise    |       |       |       |       |       |       |       |
| Integrated |       |       |       |       |       |       |       |
| Navigation |       |       |       |       |       |       |       |
| System,    |       |       |       |       |       |       |       |
| Modular    |       |       |       |       |       |       |       |
| Position   |       |       |       |       |       |       |       |
| and        |       |       |       |       |       |       |       |
| Azimuth    |       |       |       |       |       |       |       |
| System and |       |       |       |       |       |       |       |
| MA         |       |       |       |       |       |       |       |
| PS-Hybrid, |       |       |       |       |       |       |       |
| Improved   |       |       |       |       |       |       |       |
| Instrument |       |       |       |       |       |       |       |
| Azimuth    |       |       |       |       |       |       |       |
| Gyro       |       |       |       |       |       |       |       |
| Li         |       |       |       |       |       |       |       |
| ghtweight, |       |       |       |       |       |       |       |
| Gun-Laying |       |       |       |       |       |       |       |
| P          |       |       |       |       |       |       |       |
| ositioning |       |       |       |       |       |       |       |
| System,    |       |       |       |       |       |       |       |
| L          |       |       |       |       |       |       |       |
| ightweight |       |       |       |       |       |       |       |
| Laser      |       |       |       |       |       |       |       |
| Designator |       |       |       |       |       |       |       |
| Ra         |       |       |       |       |       |       |       |
| ngefinder, |       |       |       |       |       |       |       |
| Multiple   |       |       |       |       |       |       |       |
| Launch     |       |       |       |       |       |       |       |
| Rocket     |       |       |       |       |       |       |       |
| System,    |       |       |       |       |       |       |       |
| Integrated |       |       |       |       |       |       |       |
| Commu      |       |       |       |       |       |       |       |
| nications, |       |       |       |       |       |       |       |
| N          |       |       |       |       |       |       |       |
| avigation, |       |       |       |       |       |       |       |
| and        |       |       |       |       |       |       |       |
| Iden       |       |       |       |       |       |       |       |
| tification |       |       |       |       |       |       |       |
| Avionics,  |       |       |       |       |       |       |       |
| Im         |       |       |       |       |       |       |       |
| provements |       |       |       |       |       |       |       |
| in Precise |       |       |       |       |       |       |       |
| Time and   |       |       |       |       |       |       |       |
| Time       |       |       |       |       |       |       |       |
| Interval   |       |       |       |       |       |       |       |
+------------+-------+-------+-------+-------+-------+-------+-------+

**APPENDIX F**

**PVT SYSTEM GRADING RATIONALE**

**RATIONALE**

User requirements referred to are those documented in Section 4 and
Appendix A.

GREEN (G) indicates [all]{.underline} user requirements of the
particular system will be satisfied.

YELLOW (Y) indicates [some]{.underline} user requirements will be met,
but some will not.

RED (R) indicates [no]{.underline} user requirements will be met by the
system.

ASSUMPTIONS/CRITERIA: Rating systems that were fielded to meet a
specific purpose in a particular environment is, of necessity,
subjective. Assumptions and criteria used are stated below.

a\. Availability was measured against the basis of the system\'s ability
to provide required PVT information within acceptable limits documented
for signal outages.

b\. Coverage was based on the system\'s ability to provide global
coverage (a user requirement). For example, GPS LAAS provides service
within its operating radius of the LAAS transmitter, but since
transmitters are not deployed to cover the globe, it can't be rated
green for coverage.

3\. Security ratings were determined by the system\'s ability or
potential ability to operate and provide PVT information in a jamming,
spoofing, and exploitation environment, even though a system may not
have been designed with security in mind.

4\. Affordability was determined by the relative expense of that system
compared to others that provide essentially the same service. While a
system may indeed be determined to be worth its cost, it may still be
considered yellow or red because of the cost relative to similar
systems. Additionally, existing systems' projected funding levels were
also included in this analysis. For example, GPS was rated yellow
because it has budget disconnects from what is required to fully satisfy
mission requirements.

5\. Interoperability was judged based on the system\'s adaptability to
provide service to all/many users, despite its originally intended
mission. For example, Bottom Contour Navigation may well satisfy the
requirements for sub-surface/surface marine users, but it would be very
difficult, if not impossible, for that system to support aviation users.
Therefore, it received a yellow rating.

F.1 **GROUND CONTROLLED APPROACH/PRECISION APPROACH RADAR**

This system has coverage problems since a user must be within line of
sight and within a specified approach corridor from the end of an
airport runway to use these systems. The signals are unencrypted causing
security concerns. Maintenance on the transmitters is costly.

F.2 **GLOBAL POSITIONING SYSTEM**

The current stand alone system will not be able to provide the
accuracies all users will require in the future, but some users will
continue to be satisfied. System security remains to be dealt with
through protection and prevention. Characteristics rated as red or
yellow will require some kind of augmentation, such as pitot-static, or
inertial systems.

F.3 **INSTRUMENT LANDING SYSTEM**

This system is a precision approach and landing system only, and as
such, usage and coverage is limited to approach corridors to airport
runways. Availability approaches 100%.

F.4 **INERTIAL NAVIGATION SYSTEM**

Since this system is self-contained, security and survivability
generally satisfy future requirements. Timing accuracy remains a
critical shortfall. Integrity could either be acceptable, in the case of
a complete INS failure, or unacceptable, in the case of insidious drift
rates.

F.5 **LORAN-C**

This system is scheduled for deactivation, and was considered red
"across the board."

F.6 **MARITIME DIFFERENTIAL GPS**

Since the system is intended for maritime only use, signal availability
and coverage were downgraded. With system growth and maturity, these
ratings could be upgraded. Interoperability was also a weakness since
separate receivers, or at a minimum, upgraded GPS receivers are
required. Survivability of the signal is questionable in times of
conflict.

F.7 GPS WIDE AREA AUGMENTATION SYSTEM

One of the best current systems to meet future requirements, the issues
of security, survivability, and cost are still of concern.

F.8 **GPS LOCAL AREA AUGMENTATION SYSTEM**

Similar in capability to the Coast Guard's Maritime DGPS system, the
limitations for this system are, unsurprisingly, shared as well.

F.9 **MARINE AIR TRAFFIC CONTROL & LANDING SYSTEM**

This system was developed to satisfy precision traffic control and
landing for Navy and USMC aircraft at expeditionary airfields. Provides
excellent position accuracy, while velocity and timing accuracies are
limited to non-existent. Coverage is obviously limited to those fields
broadcasting this signal to arriving aircraft, typically 15 km.
Survivability is a concern.

F.10 **AIR TRAFFIC CONTROL RADAR**

RADARs are limited in accuracy capability, whether position or velocity.
Availability and coverage are dependent upon altitude, survivability is
suspect given radar homing weapons and anti-radar defenses, and security
is questionable given today's anti-radar capabilities. Maintenance costs
are high for this system.

F.11 **BOTTOM CONTOUR NAVIGATION**

Coverage of ocean bottom terrain is limited to areas that have
previously been charted. Echo sounder (sonar) is used to determine
submarine position comparing readings with bottom terrain features.
Accuracy is only about 200m. No timing information is provided.

F.12 **CARRIER SYSTEMS FOR CONTROLLED APPROACH OF NAVAL AIRCRAFT**

Limited in coverage to the approach end of aircraft carriers, and
accessible to naval aviation on approach to landing on those carriers.
Similar to ILS. Security is of concern, as is survivability. Users other
than naval aircraft would need modification to take advantage of this
system. Timing accuracy is not provided.

F.13 **CELESTIAL NAVIGATION**

Traditionally practiced celestial navigation results in typical position
accuracies of 2 nautical miles. Access to navigation information and
corrections can be improved by performing calculations electronically,
and position accuracies of 3-30 meters can be attained with automated
systems such as STELLA---The System To Estimate Latitude and Longitude
Astronomically.

F.14 **DIFFERENTIAL GPS (DGPS)**

This is a reference to the DGPS under study by DoD. Concerns exist over
security and survivability of DGPS signals. DGPS can continue to operate
while part of the system is down or corrupted. However, some accuracies
are jeopardized in the process. The issue of affordability is based on
the current development of the system as well as additional hardware
that is required for operation and use of signal. The integrity and
signal availability are currently under study.

F.15 **DIGITAL AIRPORT SURVEILLANCE RADAR**

DASR accuracies are good for cruise and general location monitoring, but
range errors cause it to become less reliable for close approach
situations. In addition, its coverage is limited to the capacity and
location of the RADAR installations, and is limited to aircraft usage.
RADAR serviceability concerns exist for the long term, and times of
disrepair may increase.

F.16 **DIRECTION FINDING**

Provides good relative accuracies for bearing measurements but
positional accuracies are not very good. Coverage limited to
line-of-sight from user to the transmitter. Simple UHF transmissions
raise security and survivability concerns.

F.17 **DOPPLER**

Position and velocity accuracies are good. However, they are reliant
upon accurate data input into the system to augment the Doppler
readings. Additionally, the precision of the information varies with the
conditions experienced by the aircraft which leads to integrity faults.
While, the Doppler system is capable of being fitted on all aircraft,
its coverage is limited to numbers of aircraft fitted with Doppler as
well as the flight regimes of the aircraft themselves. Restrictions on
flight profiles while using this system may concern some users.

F.18 **DIGITAL SCENE MATCHING AREA CORRELATION**

This system is a target area missile guidance system. Unlike TERCOM,
DSMAC is reliant upon digitized photographs of target area. Without the
photographs the system is inoperable. Missile guidance to the target
area must be accomplished by other means.

F.19 **Joint Tactical Information Distribution System**

A command and control system, JTIDS has an inherent relative navigation
capability that can be programmed to emulate, on a time-shared basis,
the performance of a TACAN transponder. Position accuracy is 75 meters,
provided a minimum of four platforms in a suitable geometric position.
JTIDS is primarily limited to line-of-sight with some exceptions for
over-the horizon, so coverage is limited. Availability is limited to
those with a JTIDS terminal. Integrity is poor at this time as its
reliability has yet to be determined.

F.20 **SURVEY INSTRUMENT, AZIMUTH GYRO, LIGHTWEIGHT (SIAGL)**

A man portable, north seeking gyro, this system provides good bearing
accuracy, but time to initialize and observe is rather high (15 minutes
each) which lends itself to security concerns for artillery surveyors,
not as much for civil surveyors. Follow-on improvements to this system
indicate directional accuracies of .2 mil within 3 minutes after setup.
Coverage is limited to 75 degrees latitude.

F.21 STABILIZATION REFERENCE PACKAGE/POSITION DETERMINATION SYSTEM

Used on Multiple Launch Rocket System (MLRS), SRP/PDS provides
direction, elevation and cant angles. The system is susceptible to
errors in calculations and provides position location using data from
two odometers connected to vehicle tracks. and requires periodic updates
at control points.

F.22 **TERRAIN CONTOUR MATCHING (TERCOM)**

Using radar and barometric altimetry to determine a 3-D position by
comparing detected terrain profiles with prestored profiles of the
terrain being traversed, coverage of TERCOM is limited to land areas
that have previously been digitized. All other land regions are
unavailable to TERCOM, as will be large bodies of water.

F.23 **VESSEL TRAFFIC SERVICES (VTC)**

VTC is limited in use. Only eight stations currently available around
the US with a limited range around their base harbor. Accuracies
generally meet the needs of vessels, however, may be lacking in cases
where precise location and velocity information are needed such as
transportation of HAZMAT. Each VTC location is self supporting yet not
very protected from possible problems. Human operators are always needed
for monitoring.

[^1]: RAIM hole is defined to be any time that at least five GPS
    satellites are not in view above a mask angle of 7.5 degrees.

[^2]: Federal Radionavigation Plan, 1994

[^3]: System includes all segments of PVT. Integrity solutions may
    involve changes to all segments.

[^4]: CJCS MOP 6, Appendix B