SatelliteOperatio

ns

SatelliteOperatio

ns

TeleCommTeleComm

Oil ExplorationOil Exploration

Trucking & Shipping

Trucking & Shipping

Surveying & MappingSurveying & Mapping

Precision AgriculturePrecision

Agriculture

GPS enables a diverse array of applications

Power GridsPower Grids

IntelliDriveIntelliDrive

NextGenNextGenTransit

Operations

TransitOperatio

ns

Disease ControlDisease Control

Personal NavigationPersonal

Navigation

Fishing & BoatingFishing & Boating

GPS Constellation Status

• Very robust constellation; exceeds user requirements

• 31 satellites currently in operation

• 11 GPS IIA

• 12 GPS IIR

• 7 GPS IIR-M

• 1 GPS IIF (set healthy 26 Aug 2010)

• 4 additional satellites in residual status

• 1 additional IIR-M waiting to be set healthy

• Global GPS civil service performance commitment met continuously since December 1993

Baseline Constellation = “24 Expandable”

3

4

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

Alternate Master Control Station

5

N/A

1.61.2 1.1

0.9

0

1

2

3

4

5

6

7

RM

S S

IS U

RE (

m)

RM

S S

ignal-

in-S

pace

Use

r R

an

ge E

rror

(UR

E),

m

ete

rs

2008 SPS Performance Standard(Worst of any SPS SIS URE)

2001 SPS Performance Standard(RMS over all SPS SIS URE)

N/A N/A N/AN/A

Selective Availability (SA)

System accuracy exceeds published standard

System accuracy exceeds published standard

Signal-in-Space User Range Error is the difference between a GPS satellite’s navigation data (position and clock) and the truth, projected on the line-of-sight to the user

1990 1992 1994 1996 1997 2001 2004 2006 20092008

1.0

Current GPS Accuracy

6

GPS Modernization

GPS II R / IIR-MGPS II R / IIR-M

20052005

• IIA/IIR capabilities plus• 2nd civil signal

(L2C)• M-Code (L1M &

L2M)

GPS IIAGPS IIA

19951995

• Standard Service• Single

frequency (L1)• Coarse

acquisition code navigation

• Precise Service• Y-Code (L1Y &

L2Y)

GPS IIFGPS IIF

20102010

• IIR-M capability plus• 3rd civil signal

(L5)• 12 year design

life

GPS IIIGPS III

2014 - 20252014 - 2025

• Backward compatible• 4th civil signal (L1C)• Increased accuracy• Increased integrity

Architecture Evolution Plan

(AEP)

Next Generation

Control Segment

(OCX)

LegacyControlSystem

7

Latest U.S. Policy

• Provide continuous worldwide access for peaceful uses, free of direct user charges

• Encourage compatibility and interoperability with foreign GNSS services

• Operate and maintain constellation to satisfy civil and national security needs– Foreign PNT may be used to strengthen

resiliency

• Invest in domestic capabilities and support international activities to detect, mitigate and increase resiliency to harmful interference

8

Summary

• GPS performance is better than ever and will continue to improve– Augmentations enable even higher

performance– New civil GPS signal available now– Many additional upgrades scheduled

• U.S. policy encourages worldwide use of civil GPS and augmentations– Permits U.S use of foreign PNT to increase

resiliency

• International cooperation is a priority– Compatibility and interoperability are critical

9

For Additional Information…

GPS.gov PNT.gov

10

Contact Information

Hank SkalskiDOT Liaison to Air Force Space

Command

Air Force Space Command Headquarters

AFSPC/OST150 Vandenberg St., Suite 1105

Peterson AFB, CO 80914

Phone: +01.719.554.2570Fax: +01.719.554.6719

Email: Hank.Skalski@peterson.af.mil