UNITED STATES OF AMERICA

GLOBAL POSITIONING SYSTEM

Status and U.S. Policy UpdateSwedish Radio Navigation Seminar

Stockholm, Sweden

October 21, 2008

Charles DanielsSenior Advisor, National Coordination Office

United States of America

22

Overview

• Introduction

• Global Positioning System

• Modernization Plans

• U.S. Policy

33

Space-Based PNT Applications Impact A Wide Range of Economic Activities

4

OilExploration

OilExploration

Fishing & BoatingFishing & Boating

AviationAviation Surveying & MappingSurveying & Mapping

Trucking & ShippingTrucking & Shipping

Satellite OperationsSatellite

Operations

Precision AgriculturePrecision

Agriculture

Power GridManagementPower Grid

Management

Personal NavigationPersonal

Navigation

CommunicationsNetwork

Synchronization

CommunicationsNetwork

Synchronization

44

Introduction

• Like the Internet, GPS is a critical component of the global information infrastructure – Scalable applications enabling broad new capabilities – Facilitating innovations in efficiency, safety,

environmental protection, public security and science

• During the past decade, GPS has grown into a global utility providing space-based positioning, navigation and timing (PNT) – Consistent, predictable, dependable policy and

performance– Augmentations improve performance

5

GPS Introduction

• Owned and operated by the U.S. Government– Funded by U.S. taxpayers

– Managed at a national level as a multi-use asset

– Acquired and operated by the U.S. Air Force on behalf of the U.S. Government per US Law Title 10, Section 2281

– 30 years of operation – 1st launch February 1978

• GPS service is a one-way broadcast, like FM radio– Unlimited number of users

– Civil GPS signals are free of direct user fees

• Public domain documentation– Available on an equal basis to users and industry

– Anyone in the world can develop GPS user equipment

66

Overview

• Introduction

• Global Positioning System

• Modernization Plans

• U.S. Policy

77

The Global Positioning System

• Baseline 24 satellite constellation in medium earth orbit

• Global coverage, 24 hours a day, all weather conditions

• Satellites broadcast precise time and orbit information on L-band radio frequencies

• Two types of signals:– Standard (free of direct user fees)

– Precise (U.S. and Allied military)

• Three segments: – Space

– Ground control

– User equipment

88

GPS Constellation Status

• 33 Satellites on Orbit– 13 Block IIA

– 12 Block IIR

– 6 Block IIR-M

– 2 Block IIA Spares

• Next launchs: – March 2009 – IIR-M 20

– August 2009 – IIR-M 21 (Last IIR)

– October 2009 – 1st Launch of IIF

31 Healthy SatellitesAs of October 17, 2008 (Baseline Constellation: 24)

31 Healthy SatellitesAs of October 17, 2008 (Baseline Constellation: 24)

99

GroundAntenna

Master Control Station (Schriever AFB)

GPS Operational Control Segment (OCS)

AscensioAscensionn

Diego Diego GarciaGarcia

Cape Cape CanaveralCanaveralHawaiiHawaii

Kwajalein Kwajalein

Schriever Schriever AFB AFB

ColoradoColorado S KoreaS Korea

AustraliaAustralia

BahrainBahrain

S AfricaS Africa

EnglandEngland

ArgentinaArgentina

EcuadorEcuador

TahitiTahiti

USNOUSNO

AlaskaAlaska

MonitorStation

New New ZealanZealandd

Vandenberg Vandenberg AFB AFB

CaliforniaCalifornia

NGA Monitor Station

OCS Monitor Station

Ground Antenna Future Monitor Station

Master Control Station

Backup Master Control Station

1010

GPS Signal in Space Performance

Global GPS civil service performance commitmentcontinuously met since 1993 (15 yrs)

Global GPS civil service performance commitmentcontinuously met since 1993 (15 yrs)

Decreasing range error

Performance Standard

4.64.3

3.02.7

2.11.8

1.51.1

0

1

2

3

4

5

6

7

1990 1992 1994 1996 1997 1999 2001 2005

RM

S U

ser

Range E

rror

(m)

2007

.92

1111

GPS SPS PS UPDATECOMPARISON OF GPS SPS PERFORMANCE PARAMETERS

GPS Performance Standard Metric

SPS Signal Specification August 1998

(user performance)

SPS Performance Standard October 2001(signal in space)

SPS Performance Standard

September 2008 *

(signal in space)

CY 2007Performance**

1

Global Accuracy All-in-View Horizontal 95% All-in-View Vertical 95%

≤ 100 meters≤ 156 meters

≤ 13 meters≤ 22 meters

≤ 9 meters≤ 15 meters

2.32 meters4.45 meters

2

Worst Site Accuracy All-in-View Horizontal 95% All-in-View Vertical 95%

≤ 100 meters≤ 156 meters

≤ 36 meters≤ 77 meters

≤ 17 meters≤ 37 meters

3.63 meters4.95 meters

3 User Range Error (URE)

NONE≤ 6 meters RMS

(Constellation RMS URE)

≤ 7.8 meters 95%, (Worst Satellite URE) equivalent to 4 m

RMS

2.29 meters RMS(Worst Satellite

URE)

4 Geometry (PDOP ≤ 6)

≥ 95.87% global ≥ 83.92% worst site

≥ 98% global ≥ 88% worst site

≥ 98% global ≥ 88% worst site

99.988% global 98.958% worst

site

5 Constellation Availability

NONE

≥ 95% Probability of 24 Healthy Satellites ≥ 98% Probability of 21 Healthy Satellites

(assumes 24 primary slots)

≥ 95% Probability of 24 Healthy Satellites ≥ 98% Probability of

21 Healthy Satellites≥ 99.999%

Probability of 20 Healthy Satellites

(assumes 24 primary slots)

100% Probability of 22 Healthy

Satellites in 24 primary slots(FY2008) ***

* Green color indicates improvement in U.S. Government commitment to GPS civil service** As measured and reported at web site (http://www.nstb.tc.faa.gov/)*** As measured and reported at web site (http://www.gps.afspc.af.mil/gpsoc/)

12

International Augmentations

Differential GPS Networks

International GNSS Service Global Differential GPS System

Space-Based Augmentation Systems

1313

Overview

• Introduction

• Global Positioning System

• Modernization Plans

• U.S. Policy

1414

Recent GPS Improvements

• Launched 3 modernized satellites in past year– Largest GPS constellation size ever

– Second Civil Signal (L2C) now on orbit

• Transitioned to modernized master control station– Improved operational flexibility and responsiveness

– Added backup control station

• Expanded GPS ground network to triple amount of monitor data sent to control station– 10-15% improvement in accuracy of GPS data

broadcast

1515

Block IIA/IIR Block IIIBlock IIR-M, IIF• Backward compatibility

• 4th civil signal (L1C)• Increased accuracy• Increased anti-jam power

• Assured availability• Navigation surety• Controlled integrity• Increased security• System survivability

IIR-M: IIA/IIR capabilities plus• 2nd civil signal (L2C)•M-Code (L1M & L2M)

IIF: IIR-M capability plus• 3rd civil signal (L5)• Anti-jam flex power

Basic GPS• Standard Service– Single frequency (L1)– Coarse acquisition

(C/A) code navigation• Precise Service– Y-Code (L1Y & L2Y)– Y-Code navigation

Increasing System Capabilities Increasing Defense / Civil Benefit

GPS Modernization Program

16

Modernized GPS – New Signals

• Second civil signal (“L2C”)–Designed to meet commercial needs–Higher accuracy through ionospheric correction–Began with GPS Block IIR-M in Sep 2005; 24 satellites: ~2014

• Third civil signal (“L5”)–Designed to meet demanding requirements for transportation safety (safety-of-life)

–Uses highly protected Aeronautical Radio Navigation Service (ARNS) band–First launch: ~2009 (GPS IIR-M Demo); ~2009 (GPS IIF); 24 satellites: ~2016

• Fourth civil signal (“L1C”)–Designed with international partners to enable GNSS interoperability–Begins with GPS Block III; First launch: ~2014; 24 satellites: ~2021

17

Benefits of GPS Modernization

•System-wide improvements in accuracy, availability, integrity, and reliability to:

– Meet increasing civil, commercial and military demands

• Higher standalone accuracy

• More robust against interference

• Provides separate more secure Military signal

• Full capability of second (L2C) and third (L5) civil signals

• Full Capability of L1C for interoperability with other GNSS

• Improved indoor, mobile, and urban use

1818

GPS III Update

• Contract for GPS III-A satellites awarded in May 08– Selective Availability feature to be eliminated

– First Launch 2013

• Contracts for Next-Generation Operational Control Segment (OCX) awarded in January 08– Will implement full functionality of L2C and L5

• Future increments of GPS III will incorporate additional capabilities– As technology matures and new requirements

are validated

1919

Overview

• Introduction

• Global Positioning System

• Modernization Plans

• U.S. Policy

2020

U.S. Policy History

• 1978: First GPS satellite launched

• 1983: U.S. President offers free civilian access to GPS

• 1996: U.S. policy establishes joint civil/military GPS management

• 1997: U.S. Congress passes law that civil GPS shall be provided free of direct user fees

• 2000: U.S. President set Selective Availability to “Zero”

• 2004: U.S. President issues U.S. Policy on Space-Based PNT

• 2007: U.S. President announces Selective Availability will no longer be built into modernized GPS III satellites

2121

U.S. Policy Promotes Global Use of GPS Technology

• No direct user fees for civil GPS services– Provided on a continuous, worldwide basis

• Open, public signal structures for all civil services– Promotes equal access for user equipment

manufacturing, applications development, and value-added services

– Encourages open, market-driven competition

• Global compatibility and interoperability with GPS

• Service improvements for civil, commercial, and scientific users worldwide

• Protection of radionavigation spectrum from disruption and interference

2222

WHITE HOUSEWHITE HOUSE

ADVISORY BOARD

Sponsor: NASA

ADVISORY BOARD

Sponsor: NASA

NATIONALEXECUTIVE COMMITTEEFOR SPACE-BASED PNT

Executive Steering Group

Co-Chairs: Defense, Transportation

NATIONALEXECUTIVE COMMITTEEFOR SPACE-BASED PNT

Executive Steering Group

Co-Chairs: Defense, Transportation

NATIONAL COORDINATION OFFICE

Host: Commerce

NATIONAL COORDINATION OFFICE

Host: Commerce

National Space-Based PNT Organization

GPS International Working Group

Chair: State

GPS International Working Group

Chair: State

Engineering Forum

Co-Chairs: Defense, Transportation

Engineering Forum

Co-Chairs: Defense, Transportation

Ad HocWorking Groups

Ad HocWorking Groups

DefenseDefense

TransportationTransportation

StateState

InteriorInterior

AgricultureAgriculture

CommerceCommerce

Homeland SecurityHomeland Security

Joint Chiefs of StaffJoint Chiefs of Staff

NASANASA

2323

Keys to the Global Success of GPS

• Program Stability and Performance– Civil service performance commitment met continuously

since December 1993

– Continuity of constellation and signals ensured through Air Force operation and acquisition

– Continuous improvements in accuracy, availability, etc.

– Funding through U.S. taxpayers

• Policy Stability and Transparency– Open access to civil GPS signals, free of direct user fees

– Open, free, and stable technical documentation

– Market-based competition worldwide

– Liberal export controls on GPS user equipment

– National-level policy coordination including civil and military leaders

• Commercial Entrepreneurship and Investment

24

U.S. Cooperation Efforts

• Cooperative relationships established with Europe, Japan, Russia, India, Australia

• U.S. goals:– Compatibility and

interoperability

– National security

– Level playing field in global markets

• Multilateral cooperation– International Committee on

GNSS

– ICAO, IMO, NATO

25

Goal of Civil Interoperability

Ideal interoperability provides users a PNT solution using signals from different GNSS systems– No additional

receiver cost or complexity

– No degradation in performanceInteroperable = Better Together Than

SeparateInteroperable = Better Together Than

Separate

26

Summary

• GPS performance is better than designed– New Civil GPS signal (L2C) now available on 6

satellites– Modernization will bring additional

improvements in Accurary and Availability.• Implementing U.S. National Space-Based PNT

Policy – National Executive Committee directly

engaged• U.S. policy encourages and promotes

worldwide use of civil GPS and augmentationsInternational cooperation through GNSS

compatibility and interoperability is a U.S. priority

International cooperation through GNSS compatibility and interoperability is a U.S.

priority

2727

For Additional Information…

Briefing available at:http://PNT.gov

28

Contact Info

Charles DanielsNational Coordination Office for Space-Based PNT

Washington, DC 20230

Tele: 202-482-6726

Email: charles.daniels@pnt.gov

Web sites: http://pnt.gov

http://gps.gov