GPS Constellation, Modernization Plans and Policy

(Bonus: DOI GPS Survey)

Milo RobinsonDOI Senior Advisor

National Coordination OfficePosition Navigation and Timing

for

USGS Geospatial LiaisonsFebruary, 2011

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

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WHITE HOUSEWHITE HOUSE

ADVISORY BOARD

Sponsor: NASA

ADVISORY BOARD

Sponsor: NASA

NATIONALEXECUTIVE COMMITTEEFOR SPACE-BASED PNT

Executive Steering GroupCo-Chairs: Defense, Transportation

NATIONALEXECUTIVE COMMITTEEFOR SPACE-BASED PNT

Executive Steering GroupCo-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 ForumCo-Chairs: Defense,

Transportation

Engineering ForumCo-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

4

Key Points

• GPS performance is better than ever and will continue to improve– Augmentations (WAAS, NDGPS, CORS) 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

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

• Introduction• Global Positioning System• Modernization Plans• U.S. Policy• DOI GPS Survey

5

Overview

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The Global Positioning System

• Baseline 24+3 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:– Free or Civil– U.S. and Allied military

• Three segments: – Space– Ground control– User equipment

GPS Constellation Status

• 11 Block IIA• 12 Block IIR• 8 Block IIR-M

– Transmitting new second civil signal– 1 GPS IIR-M in on-orbit testing

• 1 Block IIF– In Test and Checkout – First of 12 Boeing satellites

• 3 additional satellites in residual status

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

32 Operational Satellites(Baseline Constellation: 24+3)

7

8

GroundAntenna

Master Control Station (Schriever AFB)

GPS Operational Control Segment (OCS)

Ascension

Diego Garcia

Cape CanaveralHawaii

Kwajalein

Schriever AFB

ColoradoS Korea

Australia

Bahrain

S Africa

England

Argentina

Ecuador

Tahiti

USNO

Alaska

MonitorStation

New Zealand

Vandenberg AFB

California

NGA Monitor Station

OCS Monitor Station

Ground Antenna Future Monitor Station

Master Control Station

Alternate Master Control Station

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

ange 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

9

1990 1992 1994 1996 1997 2001 2004 2006 20092008

Decreasing range error1.0

Current GPS Accuracy

• Introduction• Global Positioning System• Modernization Plans• U.S. Policy• DOI GPS Survey

10

Overview

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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• Civil (Free access)– Single frequency (L1)

Coarse acquisition (C/A) code navigation

• Military– Y-Code (L1Y & L2Y)

Increasing System Capabilities w Increasing Defense / Civil Benefit

GPS Modernization Program

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Second Civil Signal (L2C)

• Designed to meet commercial needs– Higher accuracy via ionospheric

correction– Expected to generate over $5 billion

in user productivity benefits• Available since 2005• On 24 satellites by 2016

Increases accuracyfor consumers

Benefits existing professional receivers

Supports miniaturization, possible indoor use

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Third Civil Signal (L5)

• Designed to meet demanding requirements for transport safety– Uses highly protected

Aeronautical Radionavigation Service (ARNS) band

• May also enable global, centimeter-level accuracy using new techniques

• Opportunity for international interoperability

• Demonstration signal launched in 2008

• 24 satellites by 2018

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Fourth Civil Signal (L1C)

• Designed with international partners for interoperability

• Modernized civil signal at L1 frequency– More robust navigation across a

broad range of user applications– Improved performance in

challenged tracking environments– Original signal retained for

backward compatibility• Launches with GPS III in 2014• On 24 satellites by ~2021

Under trees

Inside cities

• Introduction• Global Positioning System• Modernization Plans• U.S. Policy• DOI GPS Survey

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Overview

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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 Space-Based PNT Policy

• 2007: Selective Availability removed from GPS III satellites

• 2010: U.S. President issues new National Space Policy

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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

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For Additional Information…

GPS.gov PNT.gov

• Introduction• Global Positioning System• Modernization Plans• U.S. Policy• Bonus: DOI GPS Survey

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Overview

DOI GPS Survey

• Distributed widely to Department employees

• During Spring and Summer 2010• Over 1450 responses• Including over 450 written comments

– “GPS is so integrated into what I do that everything is GPS related.”

• Responses span every bureau and every state

• Caveat: DOI survey not NCO PNT activity

Who Completed the Survey?

Technical Users20%

Coordina-tors9%

Managers7%

Users64%

Breakout by Roles

USGS26%

BLM21%

NPS19%

FWS15%

BIA6%

BOR5%

NBC4%

OSM2%

Other2%

MMS >1%

Breakout by Bureau

Major Results

• Estimate 10,000 DOI GPS users • Most are part-time users • $100-200 million invested on GPS hardware and

software• $12-24 million spent annually on maintenance • Employees need and want GPS training and

education– 58 % feel they need GPS Training

• GPS meets the broad range of positional accuracies required for DOI

• GPS coordination is valued• The largest use of GPS is for the inventory and

management of natural resources

If there is an outage,A majority of users do not have a back-up

plan

What did the Comments Say?

• “I'd like to emphasize the need for GPS coordinators and training,” summarizes the view of many comments.

• “We would benefit from upgraded technology…,” is another important point made in many comments.

Key actions suggested by the survey

• Increase training and education (a priority)• Prepare for the expanded use of GPS and

related Global Navigation Satellite Systems• Support field users• Improve coordination within Bureaus, within

DOI and with other Departments• Provide Department level coordination,

policies, and guidance on the appropriate use of GPS equipment for typical GPS applications

Recommendations

• Strategic Plan for GPSDevelop a strategic plan to guide the Department’s GPS activities. The plan, more importantly the planning process, can provide a long term framework and policy support for improving GPS use.

• Work plan for GPS Near term actions, one-to two-year time frame, are suggested by the GPS survey and should be used to launch efficiencies in GPS operations and eliminate gaps in capabilities. – A work plan for training/education is a priority.

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Contact Information

Milo RobinsonSenior Advisor

U.S. National Coordination OfficeSpace-Based Positioning, Navigation and

Timing 1401 Constitution Ave, N.W.

Washington, D.C. 20230-0001

(202) 482-0019 (703) 648-5162

Milo.Robinson@pnt.govmrobinson@usgs.gov