Practical Applications for Environment and Agriculture in Rural Africa

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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
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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

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Stainless steel rod driven to refusal
Poured in place concrete post
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(No Transcript)
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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
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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
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Misperceptions about Accuracy

• Assumptions
• It will take care of itself
• Well work on it later
• The maps look good
• The maps look accurate
• We dont really need that much accuracy
• What we have is good enough
• Just load whatever data we can get
• Its too expensive
• Too little attention and understanding

? 2000
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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
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Autonomous Positioning Before May 1, 2000
25 - 100 m

• L1C/A Code
• Selective Availability On

Worst Case Horizontal 100 m
1996 Federal Radionavigation Plan Section A2-1,
Part B http//www.navcen.uscg.mil/policy/frp1996
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Standalone Positioning Today
4 - 6 m

• L1C/A Code
• No Selective Availability
• Accuracy Improvement Initiative

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

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Resource grade GPS Positioning
1 foot
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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.)

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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

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Continuously Operating Reference Stations (CORS)

• Variety of Geodetic Quality Dual-Frequency
• Receivers and Antennas are available
• Manufacturers include
• Allen-Osborne
• Ashtech/Thales
• Leica
• Trimble

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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

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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

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(No Transcript)
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International GNSS Service Tracking Network
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Not Operational
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What is OPUS?

• NGS On-Line Positioning User Service
• Processes GPS data
• Global availability (masked)
• 3 goals
• Simplicity
• Consistency
• Reliability

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http//www.ngs.noaa.gov/OPUS
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• Unaugmented GPS for Agriculture and Environment

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Locating and Recording Natural and Cultural
Features for Local and Regional Planning
Village in Ghana
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Wild Fruit Burkina Faso
Processing Mango Guinea
Food Security and Reforestation
Improved Granary Uganda
Children Planting Trees Ghana
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Pond Construction Cameroon
Purifying Water Cameroon
Developing, Protecting, and Ensuring Water
Supplies
Solar Panels for Water Pumps Niger
Dam Improvement Madagascar
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Preparing, Monitoring, and Managing Wildfires
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Protecting and Managing Wildlife and Habitats
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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
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At the end of the Day Change can occur with GPS
Sunset in Zambia
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Contact Information

• 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 [phone]
• Fax [phone]
• Ken.Alexander_at_PNT.gov
• Presentation available http//pnt.gov

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• Backup

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