1 POPSCAN – Etudes 2012 – Présentation du 31/1/13
IAASS 21-23 May 2013
Nathalie FUENTESFrench Space Agency
General Inspection and Quality Directorate
POPSCANA CNES GEO-INFORMATION STUDY FOR RE-ENTRY RISK ASSESSMENT
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A technology watch on Geographic Information (GI)
3 Objectives
► Calculate collective risk
numerical distribution of population
over the potential fallout zone
(ELECTRA)
► Display Critical areas
large urban areas, communication
networks, sensitive human activities,
protected areas (ORESTE)
► Provide land occupation
for environmental studiesComputed ELECTRA Impact footprint and
level of risk by cell, on ORESTE display
CNES Partner : SERTIT, Image Processing and Remote Sensing Service of the
University of Strasbourg, France,
specialized in GI Production and analysis derived from Earth observation data.
delivers crisis GI and maps within the charter « Space and Major Disasters »
N. Tholey, S. Battiston, M. Studer, M. Montabord
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Geographic Information Data Sources Inventory
5 Thématics
Population
Urban areas
Communication networks
Sensitive human activities
Land occupation / protected areas
28 relevant geographic databases with
world coverage
criterias : reliability, consistency, accuracy
and resolution, update frequency,
availability and cost, delivery format
Many other relevant geographic
databases, but with continental or
national coverage
Exhaustivité PrécisionExhaustivité Précision
Ourairports (NGA – US)
Technical summary sheets were elaboratedfor all relevant GI databases, including
appreciation on exhaustivity & precision
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Digital analysis, selected GI datasets
Population grids: Landscan 2010 GPWv3 2010
Urban areas: GRUMP Natural Earth Data VMAP0 ESRI GLOBCOVER DMSP ISA
Airports: OpenFlights OurAirports ESRI VMAP0 DAFIF
Global analysis impossible on whole world : Test areas defined in France,
French Guyana, Canada, Philippines, Indonésia, Africa, …
Landscan 2010 (ORNL - US)
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Digital analysis, method
Population grids : numerical comparisons with United Nations Organisation
population estimates, national statistic census on different sizes of administrative
units (state, regions, provinces, cities, …). Analyses on extrem values.
Population UNO (http ://esa.un.org/unpd/wpp/unpp/panel_population.htm) Canada Test Zone,and Statistic Institut of Canada (http ://www5.statcan.gc.ca/) references usedAdministrative limits : GADM (http://www.gadm.org/)
Urban areas : comparisons with urban coverage observed on satellite images.
Calculation of rates of detection, omission and over coverage.
Manilla Zone
ALOS AVNIR image and urbanarea of reference
Airports : comparisons with airports detected on satellite images. Calculation of
completeness rate, localisation precision.
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Test areas
Europe – France – South West, Bordeaux and Pau Zone
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North America – Canada – Ontario and Quebec - Timmins zone
Test areas
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South America – French Guyana
Test areas
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Asia – Philippines – Manilla zone
Test areas
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Asia – Indonesia – Banda Aceh zone
Test areas
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Africa – Burundi, Democratic Republic of Congo, Rwanda – Bukavu and Bujumbura zone
Test areas
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Results, population grids
About population distribution, two global
models are suitable :
►The gridded population of the world
GPWv3 updated and distributed by the
Center for International Earth Science
Network (CIESIN) at Columbia University.
This grid is the current CNES reference
database for ELECTRA calculations.
► The LandScanTM global population
database, produced by the Oak Ridge
National Laboratory ORNL, and
distributed by Eastview Company.
These two models are available on a grid format, allowing numerical
estimations on risks, and easy display via a geographic information system.
GPWv3 extrapolation 2010 (Ciesin)
on South West of France
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Results, population grids
GPWv3 and LandScanTM comparison, with advantages in green and limits in orange
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Results, population grids
Under estimation GPWv3 on world scale
and very often on national scale
(exception Guyana with major LANDSCAN under estimation)
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Results, population grids
Under estimation
GPWv3 observed on
national scale
(exception Guyana
with major
LANDSCAN under
estimation)
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Results, population grids
Under estimation GPWv3 on region scale (ex. Canada)
LANDSCAN GPWv3 2010
Difference with Statcan (Statistics Canada) in %
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Results, urban areas
Large imprecisions on many GI databases : omissions or over estimation on urban surfaces
Most conservative GI on a world scale : GRUMP (CIESIN, US) but no recent updateMost accurate GI on a world scale : DMSP ISA (NGA, US)
Taux de
détection
Taux
d’omission
Taux de
commission
DMSP ISA evaluation
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Results, airports
Ourairport (NGA, US) offers the
best completeness, even on
heliports and also the best
localisation precision.
Exhaustivité PrécisionExhaustivité Précision
19 POPSCAN – Etudes 2012 – Présentation du 31/1/13
Conclusion
Population grids comparison on GPWv3 and LandScanTM points out an
under estimation of global population for GPWv3 2010 projected grid, and a
suspension of updates. LandScanTM offers a better resolution and is updated
every year but does not provide any opportunity for extrapolation.
POPSCAN study will improve analysis
on urban areas and sensitive human
activities Geographic Information.
Next step is to study the construction
of a Air-traffic density mapping
with a world coverage, regular updates
and extrapolation capacity.
Openflights” , East coast of US
