1. 1 Nationwide Differential GPS (NDGPS) Real-Time Data Streaming Federal Geodetic Control Subcommittee Silver Spring, MD January 10, 2012 Timothy A. Klein Senior Policy Advisor/RITA NDGPS Coordinator Timothy.Klein@dot.gov NDGPS@dot.gov

2. 2 GPS-Based Applications are Critical to Major DOT Initiatives Reliable and accurate positioning worldwide Reduced delays More fuel-efficient routes Increased system capacity with enhanced safety Aviation – NextGen ITS/Connected Vehicle Rail – Positive Train Control Reduced probability of collisions Increased efficiency and capacity Rapid rail structure and conditioning mapping Enable crash prevention among vehicles and between vehicles and infrastructure Increased mobility and reduced environmental impact

3. 3 NDGPS Applications Partners Department of Commerce –Continuously Operating Reference Stations –Severe Weather Forecasting – water vapor estimates to national weather models –Space Weather Monitoring – free electron mapping Federal Resource Agencies (USDA, NPS, USGS) –One meter real-time positioning and navigation –Fire management and safety –Survey and mapping; GIS applications State, County and Local Governments, Private and Non-Profit Sectors –Lands, parks and environmental resources management –Precision agriculture –Mining and other resource management

4. 4 NDGPS Program Status Inland (DOT) Tower Recapitalization –Upgrade reference stations/integrity monitors/antenna –Install IP-based operations system –Upgrade transmitters –Receiving FY12 funding to begin Buildout Unlikely –No DOT support for construction funding –Strong support for O&M and recap USCG Status –Reduced requirements; budget concerns –Looking at future of broadcast system; timing backup? –FY12 study of NDGPS real-time accuracy estimates and measurements “Market Reality” Status –Limited interest in commercial use of broadcast signal –Few DGPS board manufacturers; firms leaving the field –No new program budgeting for civil positioning/navigation

5. 5 Potential “Best Uses” of a National Asset Strengthening the Asset for 10 -15 Years –But will the broadcast mission last that long? –Is there a role for streaming NDGPS observables, with or without broadcast? –Whom could this investment serve? Strongest Continuing User Group – CORS User Community –Robust, service availability-guaranteed CORS sites –23% of CORS solutions use an NDGPS-CORS site –Data streaming in RTCM format test-proven (1cm horizontal, 3cm vertical) –Would prefer to maintain broadcast capability Continuing requirement - transportation services –Can streaming data meet dynamic accuracy requirements? –Desire to complete HA-NDGPS broadcast prototype Questioning requirement – Coast Guard/maritime –Can streaming data meet positioning and navigation requirements? –Can streaming data improve harbor safety?

6. 6 NGS Streaming of CORS Data (including NDGPS) Single Baseline of 55 kms to Streaming Station Using Trimble R8 Model 3 GNSS Using a Trimble GeoXH 2008

7. 7 Pluses: Free Easy to use with receiver built in support Only one GPS receiver required Provides real-time, dual-frequency RTK positioning. Some streaming sites provide GLONASS data. Open source so other entities can produce a value-added product Minuses: Requires cell phone coverage and an unlimited data cell plan which can be expensive Data link drains the cell battery in relatively short amount of time (about an hour so external power is recommended ) Lat/Long reference frame is ITRF. This can add an unnecessary level of complication to integration with existing NAD83 referenced data. Single baseline The number of streaming sites is limited at this time NGS Streaming of CORS Data (including NDGPS)