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Practical Applications for Environment and Agriculture in Rural Africa

This session explores the practical applications of Global Navigation Satellite System (GNSS) technologies in agriculture and environmental sectors in rural Africa. It covers topics such as geodetic control, spatial data accuracy, and the importance of high accuracy data. The session also discusses the use of resource-grade GPS for achieving accurate Geographic Information Systems (GIS), and the role of Continuously Operating Reference Stations (CORS) in providing accurate positioning.

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Practical Applications for Environment and Agriculture in Rural Africa

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  1. Practical Applications for Environment and Agriculture in Rural Africa Session 4: GNSS implementation and uses in agriculture and environment United Nations/Zambia/ESA Regional Workshop on the Applications of Global Navigation Satellite System Technologies in Sub-Saharan Africa 26 June 2006, Lusaka, Zambia Presented on behalf of : Dave Doyle, Chief Geodetic Surveyor DOC National Oceanic and Atmospheric Administration, National Ocean Service National Geodetic Survey & Michael Rasher, National GPS CoordinatorUSDA Natural Resources Conservation Service National Cartography & Geospatial Centerby Ken Alexander Senior AdvisorNational Space-Based PNT Coordination Office

  2. Geodetic Control • Network of monumented points • Precisely measured in accordance with standard procedures • Meets accuracy specifications • Adjusted to tie together and documented for multiple uses

  3. Stainless steel rod driven to refusal Poured in place concrete post

  4. Spatial Data Accuracy • Accuracy crucial to building useful Geodetic Information Systems (GISs) • GIS builders and users must understand: • Impact of data accuracy • Details of spatial data accuracy • Spatial data accuracy needs • Surveying and mapping professionals should: • Understand accuracy needs of users • Be involved in data design and collection  2000

  5. Why High Accuracy • Realistic, useable representation of data • For local government, facilities management, utility and other applications • Large scale applications can be conducted • Maps and decision making information reliable • Data can be aligned and easily integrated • Survey data and GPS data can be input directly • High accuracy data saves expense for many operations  2000

  6. Misperceptions about Accuracy • Assumptions: • It will take care of itself • We’ll work on it later • The maps look good • The maps look accurate • We don’t really need that much accuracy • What we have is good enough • Just load whatever data we can get • It’s too expensive • Too little attention and understanding  2000

  7. Results of Inadequate Data Accuracy • Data mismatches, inconsistencies, lack of registration • Confusion • Battling basemaps • Wasted resources • Decisions based on “bad” data • Decisions based on in appropriate data • Lawsuits • Failed projects  2000

  8. Autonomous Positioning: Before May 1, 2000 • L1C/A Code • Selective Availability On 25 - 100 m Worst Case Horizontal 100 m 1996 Federal Radionavigation Plan Section A2-1, Part B http://www.navcen.uscg.mil/policy/frp1996

  9. Standalone Positioning Today • L1C/A Code • No Selective Availability • Accuracy Improvement Initiative ~ 4 - 6 m

  10. Unaugmented Positioning: next decade Improved resistance to interference and availability ~ 1 – 3 m Standalone GPS, Galileo, GLONASS Combined constellations to provide modest accuracy improvements?

  11. Achieving Accurate GIS • GIS needs: resource (survey) grade GPS • Accuracy ~ one foot • GPS data can be used to adjust other data • Can be used for survey control • GPS = Accuracy

  12. Resource grade GPS Positioning: ~ 1 foot

  13. Large Area High Accuracy Differential Reference System • ACCURATE: cm accuracy on a global scale • MULTIPURPOSE: Best Support for: Geodesy, Geophysics, Surveying, Navigation, Mapping, Charting and other GIS activities • ACTIVE: Accessible through Continuously Operating Reference Stations (CORS) and other post processed (derived) products • INTEGRATED -- Support International services and standards (e.g. International Earth Rotation Service, International GPS Service etc.)

  14. Continuously Operating Reference Stations (CORS) Installed and operated by diverse, Federal, State, International and local Agencies • NOAA/National Geodetic Survey • NOAA/OAR Forecast Systems Lab • U.S. Coast Guard - DGPS/NDGPS • Corps of Engineers - DGPS • FAA - WAAS/LAAS (Future) • State DOTs • County and City • Academia • Private Companies

  15. Continuously Operating Reference Stations (CORS) • Variety of “Geodetic Quality” Dual-Frequency • Receivers and Antennas are available • Manufacturers include: • Allen-Osborne Ashtech/Thales Leica • Trimble

  16. CORS Requirements • Receiver/Antenna at least dual frequency (L1 and L2) • Very stable mounting • Reliable power available • Provider has on-site Internet access • Secured location • Approximate cost ~ $30 – 50k each

  17. Continuously Operating Reference Stations (CORS) • International Terrestrial Reference Plane Coordinates • Network data collection - Hourly & Daily • Daily 3D Network Integrity Adjustment • Public Data Distribution - Internet • (http://www.ngs.noaa.gov/CORS/cors-data.html) • 11 Year • NGS Provides: • Global On-Line Data Holding

  18. International GNSS Service Tracking Network

  19. Not Operational

  20. What is OPUS? • NGS On-Line Positioning User Service • Processes GPS data • Global availability (masked) • 3 goals: • Simplicity • Consistency • Reliability

  21. You’ve got mail! OPUS solution http://www.ngs.noaa.gov/OPUS

  22. Unaugmented GPS for Agriculture and Environment

  23. Locating and Recording Natural and Cultural Features for Local and Regional Planning Village in Ghana

  24. Wild Fruit Burkina Faso Processing Mango Guinea Food Security and Reforestation Improved Granary Uganda Children Planting Trees Ghana

  25. Purifying Water Cameroon Pond Construction Cameroon Developing, Protecting, and Ensuring Water Supplies Solar Panels for Water Pumps Niger Dam ImprovementMadagascar

  26. Preparing, Monitoring, and Managing Wildfires

  27. Protecting and Managing Wildlife and Habitats

  28. “We must feed our people, have safe drinking water, treat the ill ...transportation, exports and other things will come in time. “ Global Positioning System Practical Applications for Agriculture and Environment in Rural Africa

  29. At the end of the Day… Change can occur with GPS Sunset in Zambia

  30. Ken Alexander, Senior Advisor National Space-Based PNT Coordination Office Herbert C. Hoover Bldg., Rm. 6822 1401 Constitution Avenue, NW Washington, D.C. 20230 Ph: (202) 482-5809 Fax: (202) 482-4429 Ken.Alexander@PNT.gov Presentation available: http://pnt.gov Contact Information

  31. Backup

  32. How Does OPUS Work? NGS-PAGES software used 3 “best” CORS selected3 separate baselines computed3 separate positions averaged

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