10/05/07 1

Update on DOT Nationwide Differential GPS (NDGPS) Program

Presentation to:

National Space-Based Positioning, Navigation and Timing Advisory Board

Doubletree HotelWashington, DC

Timothy A. KleinSenior Policy Advisor/RITA NDGPS Coordinator

NDGPS@dot.gov

U.S. Department of Transportation

Research andInnovative TechnologyAdministration

10/05/07 2

What is NDGPS?

• Nationwide Differential GPSAugmentation system composed of:

USGC/Maritime DGPS for Harbor/Entry Approach → 39 sites

USACE Sites for Inland Waterways → 9 sites DOT/Inland NDGPS for Terrestrial

Applications → 38 sites IOC = Single coverage over CONUSFOC = Dual coverage over CONUS Inland NDGPS currently 8 sites short of IOC

U.S. Department of Transportation

Research andInnovative TechnologyAdministration

10/05/07 3

NDGPS System Characteristics

• Accuracy1 – 3 meters at up to 150 km (10 m requirement)0.5 meter near the reference station5 cm with post-processing (CORS)Many field users report better results

• Integrity5 seconds at 100 bps2.5 seconds at 200 bps

• Designed for Use in Impeded Environments

U.S. Department of Transportation

Research andInnovative TechnologyAdministration

10/05/07 4

NDGPS Services

• NDGPS Provides to Multiple User Communities:Sub-meter accuracy in multiple terrestrial

applicationsAccurate real-time positioning in all surface

environments, including impeded environments (mountains, valleys, tunnels, urban canyons)

Post-processed data for increased accuracy for resource management and mapping

U.S. Department of Transportation

Research andInnovative TechnologyAdministration

10/05/07 5

NDGPS Partnerships

• Partners Currently Relying on NDGPS DataNational and Cooperative Continuously

Operating Reference Stations (CORS) Robust backbone stations for CORS Post-processing for repeatable survey,

mapping, and resource management applications.

National Oceanic and Atmospheric Admin. National Weather Service/Water Vapor Space Weather Prediction Center

UNAVCO Tectonic Plate Monitoring

U.S. Department of Transportation

Research andInnovative TechnologyAdministration

10/05/07 6

National Space-Based PNT ExecCom Action

• Action: DOT complete assessment of the need for inland component of NDGPSFinal resolution of to be determined by:

interagency requirements level of support

If no transportation requirements or other Federal user requirements, DOT intends to develop decommissioning plan for NDGPS

DOT cost share with other agencies possible if there is a transportation requirement

Due date: January 30, 2008

U.S. Department of Transportation

Research andInnovative TechnologyAdministration

10/05/07 7

Assessment Activities• Federal Register Notice (Closed 10/1/07)

Seeks requirements for continuing current inland NDGPS operations, completing NDGPS IOC or FOC

Seeks funding partnershipsStates that if further investment not in public

interest, DOT will plan decommissioning • Letters to Federal Agencies (In Work)

Seeks mission requirements for NDGPSSeeks funding sponsorship

• Independent Assessment (ARINC)Assess private sector/commercial requirementsAssess economic impacts

U.S. Department of Transportation

Research andInnovative TechnologyAdministration

10/05/07 8

NDGPS Funding• DOT FY08 Funding = $5M

Included in President’s request for DOT and in both Appropriations bills

Existing NDGPS maintenance and operations only; no construction/upgrade for sites

• DOT FY09 Funding = ??? If DOT does not fund inland NDGPS in FY09, USCG

has identified 12 DOT Funded Sites to preserve Maritime coverage.

• No matter the outcome for inland NDGPS, USCG will continue to operate and maintain Maritime DGPS

U.S. Department of Transportation

Research andInnovative TechnologyAdministration

10/05/07 9

Current Maritime + Inland NDGPS Coverage

Approximately 92% of the lower 48 states has single coverage and 65% has dual coverage.

10/05/07 10

Possible FY09 Maritime DGPS