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Kharita Challenges

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Real geospatial problems, graded automatically. Choose a track, a level and what you want to hand in.

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Spatial Analysis2 problemsPostGIS / SQL1 problemPython3 problemsRemote Sensing1 problemCartography1 problemWeb GIS0 problemsData Management7 problemsGIS Architecture0 problems
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SQL1 problemPython0 problemsGeoJSON0 problemsAnswers0 problemsSchema0 problemsDecisions0 problemsDataset file0 problems
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Data preparation2 problemsData quality1 problemSpatial analysis4 problemsRaster analysis0 problemsCartography0 problemsDecision support4 problemsGeospatial systems1 problemWeb delivery1 problem
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PostGIS / SQLData qualityClear all
  1. Not started, Are these country polygons fit to assign cities to?Data qualitySQL

    A point-in-polygon audit that exposes what 1:50m generalisation does to a coastline — and which places the attribute and the geometry disagree about.

    PostGIS / SQLadvancedDifficulty: advanced300 XP~45 min5 checks

    You hand in a spatial SQL query.

    Datasets

    • Populated places · Point · 1,251 features · EPSG:4326
    • Countries · MultiPolygon · 241 features · EPSG:4326

    What you’ll do

    • Join points to the polygon containing them with an outer join
    • Compare an attribute to a derived value with NULL-safe semantics
    • Return the disagreement list, including the points nothing contains
    ST_Containsouter joinIS DISTINCT FROMgeneralisationdata qualityAlso trains Data Management
    Open problem