Application of GIS to Fast Track Planning and Monitoring of Development Agenda

Transcription

1 Application of GIS to Fast Track Planning and Monitoring of Development Agenda Advantages & Disadvantages of RS August 2018

2 ADVANTAGES Large areal coverage (inaccessible areas) Resolutions spatial/spectral/radiometric/temporal Multi sensors Multi users Operational monitoring Myriad of Applications Combinations & Integration Data democracy & Costs

3 ADVANTAGES -Images do not lie -Gives aerial view of an area which cannot be seen from the ground -See what the human eye cannot see -Large area coverage -Can acquire data from inaccessible regions -Operational observation system from space -geostationary or polar orbiting

4 ADVANTAGES (Spatial resolution) From global -> continental -> regional -> local -> your house or 18 th hole on your preferred golf course

5 OCEANOGRAPHY Sea surface temperature, altimetry, algae production ADVANTAGES (Spectral Resolution)

6 ADVANTAGES (Radiometric Resolution) 2 Bit 4 grey shades 8 Bit 256 grey shades

7 ADVANTAGES (Temporal Resolution) Urban development monitoring Disaster (fire monitoring) July 2003 Drought monitoring July 2002

8 ADVANTAGES (Multi-sensors) - Passive/active sensors - Data manipulation -Data Fusion RGB=1997,2000,2004 RADARSAT 2 over Queen Maud land ANTARCTICA = SANEA IV Resolution merge of 10m MS and 2.5m panchromatic

9 ADVANTAGES (Multi-users) National Stakeholders Government Departments Data provision to government departments (Single license multi-user arrangement) Value-added data products and services

10 ADVANTAGES (Operational Monitoring) Detect and display active fire using each WAMIS sensor constellation overpass Operate on both internet and SMS alert

11 ADVANTAGES (Myriad of Applications) Aerosol Properties Ambient Nitrogen Dioxide Concentration Ambient Ozone Concentration Ambient Particulate Matter (fine) Composition Ambient Particulate Matter Composition (coarse) Ambient Particulate Matter Concentration (coarse) Ambient Particulate Matter Concentration (fine) Ambient Sulphur Dioxide Concentration Ambient Volitile Organic Compounds Bathymetry Biodiversity Biomass Burned Area/Fires Carbon (stores, uptake, flux) Cloud Cover (cloud index) Cloud Parameters (Other) Cloud Water/Ice Amounts (3D Distribution) Column Nitrogen Dioxide Concentration Column Ozone Concentration Column Particulate Matter Concentration (coarse) Column Particulate Matter Concentration (fine) Column Sulphur Dioxide Concentration Contaminants/Pollutants (Inorganic/Organic) Cultivation Currents Curvature Deforestation Desertification Direct Normal Irradiation (DNI) Elevation Evaporation Evapotranspiration EVI Floods Forest Cover Forest Management Practices Forest Structure Fraction of Absorbed Photo synthetically Active Radiation (FAPAR) Fraction of Photo synthetically Active Radiation (fapar) Fuel Load/Characteristics Glacier/Ice Cap Elevation Glacier/Ice Sheet Depth Glacier/Ice Sheet Extent Global Horizontal Irradiation (GHI) Gross Primary Productivity Groundwater Lake/Reservoir Levels Land Cover Land Surface Temperature Land Use Leaf Area Index Net Primary Productivity (NPP) Non-Native Species Normalized Difference Vegetation Index (NDI) Nutrients (Phosphorous, Nitrogen, Potassium, Nitrates, Sulphates) Ocean Salinity Ocean Topography Photo synthetically Active Radiation (PAR) Population Pore Pressure Precipitation Rock Strength, Permeability, Spacing, orientation SAVI Sea Ice Cover Sea Level Sea Surface Temperature (SST) Seismicity Slip Slope Angle Slope Movement Snow Cover Extent Snow Depth Snow Water Equivalent (SWE) Soil Carbon Soil Composition Soil Moisture Soil Thickness Strain Stream/River Flow, Discharge, Height, Stage Surface Air Temperature Surface Atmospheric Pressure Surface Deformation Surface Humidity Surface Radiation Budget Surface Wind Direction Surface Wind Speed Upper Level Humidity Upper Level Temperature Upper Level Winds Urbanization Vector Population Vegetation Cover Vegetation Type Water Bodies (location) Water Quality & Composition, ph and salinity, Dissolved Oxygen Content Water Run-Off Water Use

12 ADVANTAGES (Combination & integration) Combining sensors leads to temporal, spectral, spatial and cost benefits. Understanding integration and acquisition schedules offers possible solutions Costs per area and objectives Can be optimised

13 ADVANTAGES (Data democracy & costs) Relatively cheap compared to traditional methods of surveying. Many data providers have opted for data democracy. Costs if any are limited to extraction and processing as costs of production and delivery Many are freely available to the scientific community Many more are commercial but prices are becoming accessible

14 DISADVANTAGES Subjectivity - Interpretation Clouds Atmospheric/Radiometry (haze) Lifetime of instruments Skills requirement

15 DISADVANTAGES (Data inherent) Clouds Uncalibrated CCDs Band misalignment Missing bands. Positional accuracies

16 DISADVANTAGES Subjectivity - Interpretation Translating pixels images into classes without in-situ measurements remains a subjective interpretation on what represents what on the ground (see legend) Classification becomes simpler as more spectral bands become available. Compare: Panchromatic -> Hyperspectral

17 DISADVANTAGES (Clouds) The biggest disadvantage with optical sensors remain clouds which force additional steps like cloud removal to be able to harvest some of the acquisition

18 DISADVANTAGES (Atmosphere) Atmospheric interference (Haze, pollution, ice particles, etc.) becomes a handicap in RS measurements and necessitate additional steps like haze removal to enable interpretation of the results.

19 DISADVANTAGES (Instrument lifetime) RS instrument expensive to build and operate Instruments design limited by lifetime When the satellite reach end of life, acquisition of data ceases

20 DISADVANTAGES (Skills requirement) Theoretical knowledge Practicality and application skills Software competency

21 LIMITATIONS Subjectivity Clouds, Atmosphere, Radiometry Resolution (Spectral and Spatial) Classification Expense Temporal return

22 LIMITATIONS (Resolution) KLERKSDORP March a fierce storm damages homes & schools Before image 03/03/07 After image 3/13/07 Visual interpretation is subjective and remains so despite the help of automatic change detection but RS remains a good indicator of the change locations

23 LIMITATIONS (Classification) Inherent Challenges Shadows in the mountains or burned fields render the same signature as water bodies and require extra efforts to be circumvented for a perfect classification.

24 LIMITATIONS (Expense) Spot 5 Quick Bird LIDAR Accuracy 7m 2,5 meter 10-5cm Resolution m 0,6-2,5m Up to 5cm Delivery from order time 5 days 14 days 6 weeks Cost/km² R26 R150 R1 500 Number Tiles +/ / / Km²/Tile Time to cover SA 6 months 4 years 3 years Cost imagery Per coverage p/a R R R

25 LIMITATIONS (Temporal return) Example of monitoring considerations : Temporal vs Spectral vs Resolution JUNE JULY AUGUST SEPTEMBER MODIS m 250 LANDSAT 30m SPOT4 20m SPOT5 10m A calendar of sensors acquisitions is a must, knowledge of their individual contributions and their value add potential must be aligned with the application.

26 Thank You

27 WHAT? CURRENT TRENDS Data access & dissemination routes FROM On SANREN network 1GBps in RSA, HBK tested 500Mbps internationally TO Eumetcast or new SENTINEL model What about the Google Earth REVOLUTION

28 Data, Products and Services User Private Sector Government Students DPS Customer Services Reselling very high res data Reselling very high res data Extraction and data archiving Image Processing CXFS DMF Value Added Products Spot 5 annual mosaic Spot 5 subsets Ad hoc Fire Scar Mapping Fundisa Disk Processed Products

29 3D 3D navigation over Toulouse city Airborne Simulation And Toulouse City urban data base

30 Surface Water Evolution over the DEM 100 hours run NO 2 hours (red), 50 hours (green) and 100 hours (blue).

31 Contact us Website: Tel: (reception) ask for Customer Services Earth Observation