Ten datasets, one decision: a field guide to built-up area products
Why the choice matters
Global built-up-area products can disagree for entirely reasonable reasons: they use different sensors, definitions, training data, spatial resolutions and update cycles. A product that performs well for national trends may be the wrong choice for neighbourhood-scale exposure analysis.
Start with the decision context
Before comparing maps, define the question. Are you measuring long-term urban growth, locating individual settlements, estimating exposed population or tracking post-disaster change? The required scale, date range and tolerance for false positives follow from that decision.
Compare before you commit
A practical assessment combines visual inspection with reference locations and a small set of repeatable metrics. The goal is not to crown a universal winner, but to document which product is fit for this analysis and where its limitations should shape the final recommendation.