GFDRR/sirs-compare

Compare open school-location sources (OpenStreetMap vs Overture Maps) over satellite imagery - SIRS West Africa. # SIRS Compare **Live app: gfdrr.github.io A lightweight public web app to compare **open** school-location datasets over high-resolution satellite imagery for five West African countries: **Niger, Guinea, Mali, Benin, and Ghana**. Pick a country, switch to the **Agreement** view to see which schools appear in both OpenStreetMap and Overture Maps and which are unique to one source, check how well their names agree, and toggle on building footprints and campus polygons to compare points against actual school compounds on the imagery. This app deliberately includes **only open data** (OpenStreetMap and Overture Maps). UNICEF Giga school data is **intentionally excluded** from this public app and is compared separately in a private variant. ## What it shows - **Basemap**: Esri World Imagery (with an optional OpenStreetMap street basemap toggle). - **Country selector** that loads each country's layers and zooms to it. - **Two view modes**: - *By source*: OpenStreetMap schools (green) vs Overture Maps education places (orange). - *Agreement*: points colored by cross-source match status - in both (cyan), OSM only (green), Overture only (orange) - with dashed connector lines between matched pairs when zoomed in. - **Match analysis panel**: matched pair count, share of Overture found in OSM, median offset between matched points, and name agreement rate for the selected country. - **Footprint layers**: - *OSM school grounds*: `amenity=school` polygons (campus/compound outlines). - *OSM school buildings*: `building` footprints that intersect school grounds, are tagged as schools (`building=school` / `amenity=school`), or contain an `amenity=school` node. Each popup states why the building qualifies. - *Overture edu buildings*: building footprints tagged `subtype=education`, drawn as a dashed orange outline so the solid OSM buildings stay visible underneath - solid green is OSM-only, green with an orange ring is in both, a dashed orange ring alone …