Practical Applications for Environment and Agriculture in Rural Africa Session 4: GNSS implementation and uses in agriculture and environment United Nations/Zambia/ESA

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 Coordinator

USDA Natural Resources Conservation Service National Cartography & Geospatial Center

byKen AlexanderSenior Advisor

National Space-Based PNT Coordination Office

2UN Workshop Zambia27 June 2006

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


Poured in place concrete post

Stainless steel rod driven to refusal



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


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


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


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


Autonomous Positioning: Before May 1, 2000

• L1C/A Code • Selective Availability On

25 - 100 m

Worst Case Horizontal 100 m1996 Federal Radionavigation PlanSection A2-1, Part Bhttp://www.navcen.uscg.mil/policy/frp1996


Standalone Positioning Today

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

~ 4 - 6 m


Unaugmented Positioning: next decade

~ 1 – 3 m

Improved resistance to interference and availability

Standalone GPS, Galileo, GLONASS

Combined constellations to provide modest accuracy improvements?


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


Resource grade GPS Positioning:

~ 1 foot


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.)


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



Variety of “Geodetic Quality” Dual-Frequency

Receivers and Antennas are available

Manufacturers include:

Allen-Osborne

Ashtech/Thales

Leica

Trimble


•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

CORS Requirements



• 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



International GNSS Service Tracking Network


Not Operational


What is OPUS?• NGS On-Line Positioning User

Service

• Processes GPS data

• Global availability (masked)

• 3 goals:

– Simplicity

– Consistency

– Reliability


http://www.ngs.noaa.gov/OPUS

You’ve got mail!

OPUS solution


Unaugmented GPS for Agriculture and

Environment


Locating and Recording Locating and Recording Natural and Cultural Features Natural and Cultural Features

for Local and Regional for Local and Regional PlanningPlanning

Village in Ghana


Wild FruitWild Fruit Burkina FasoBurkina Faso

Processing MangoProcessing Mango GuineaGuinea

Children Planting TreesChildren Planting Trees GhanaGhana

Improved GranaryImproved Granary UgandaUganda

Food Security and ReforestationFood Security and Reforestation


Dam ImprovementDam Improvement MadagascarMadagascar

Solar Panels for Water PumpsSolar Panels for Water Pumps NigerNiger

Pond ConstructionPond Construction CameroonCameroon

Purifying WaterPurifying Water CameroonCameroon

Developing, Protecting, and Ensuring Water SuppliesDeveloping, Protecting, and Ensuring Water Supplies


Preparing, Monitoring, and Managing WildfiresPreparing, Monitoring, and Managing Wildfires

29UN Workshop Zambia27 June 2006Protecting and Managing Wildlife and Habitats Protecting and Managing Wildlife and Habitats


Global Positioning SystemPractical Applications for Agriculture and Environment

in Rural Africa

“We must feed our people, have safe drinking water, treat the

ill ...transportation, exports and other things will come in time. “


Sunset in Zambia

At the end of the Day…

Change can occur with GPS


Contact Information

Ken Alexander, Senior AdvisorNational Space-Based PNT Coordination Office

Herbert C. Hoover Bldg., Rm. 68221401 Constitution Avenue, NW

Washington, D.C. 20230Ph: (202) 482-5809Fax: (202) 482-4429

[email protected]

Presentation available: http://pnt.gov


Backup


NGS-PAGES software used

3 “best” CORS selected3 separate baselines computed3 separate positions averaged

How Does OPUS Work?

Documents

Practical Applications for Environment and Agriculture in Rural Africa Session 4: GNSS implementation and uses in agriculture and environment United Nations/Zambia/ESA