Skip to content
Kharita Challenges

Problems

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

2 of 59 problems

Pick one for me
Track
Spatial Analysis0 problemsPostGIS / SQL1 problemPython1 problemRemote Sensing0 problemsCartography0 problemsWeb GIS2 problemsData Management0 problemsGIS Architecture1 problem
Level
Beginner1 problemIntermediate3 problemsAdvanced2 problemsExpert0 problems
Hand in
SQL1 problemPython1 problemGeoJSON0 problemsAnswers2 problemsSchema0 problemsDecisions0 problemsDataset file0 problems
Category
Data preparation1 problemData quality0 problemsSpatial analysis0 problemsRaster analysis1 problemCartography1 problemDecision support3 problemsGeospatial systems0 problemsWeb delivery2 problems
Sign in to track progress
AdvancedWeb deliveryAnswersClear all
  1. Not started, Deliver a compact sewer review mapProjectWeb delivery3 steps

    Extract a review cohort, make its browser payload inspectable, and measure the transfer budget.

    Web GISadvancedDifficulty: advanced580 XP~90 min9 checks

    Worked in 3 steps, each checked before the next one opens.

    1. Extract the review cohort · SQL
    2. Prepare the browser layer · Python
    3. Measure the transfer budget · Answers

    Dataset

    • NYC 311 sewer requests, 1–7 June 2025 · Point · 408 features · EPSG:4326

    What you’ll do

    • Query the exact review cohort
    • Serve a compact, inspectable WGS 84 point layer
    • Measure raw and compressed payload size from the delivered layer
    NYC 311urban servicestemporal GISheat mapGeoPandasAlso trains PostGIS / SQL, Python
    Open project
  2. Not started, Polling a live feed: what does it cost per day?Web deliveryAnswers

    Size the transfer cost of a live layer from the file as served — uncompressed, gzipped, and per day at scale — before choosing between polling and push.

    GIS ArchitectureadvancedDifficulty: advanced280 XP~35 min3 checks

    You hand in your answers as values.

    Dataset

    • Santander Cycles docking stations (live snapshot) · Point · 799 features · EPSG:4326

    What you’ll do

    • Measure a payload as served rather than as re-encoded
    • Quantify what transport compression buys
    • Extrapolate a polling design to a daily transfer figure
    capacity planningpollinggzippayloadarchitectureAlso trains Web GIS
    Open problem