Mapping Lines of Sight

William Davies has created a really interesting demo map that uses turf.js to map viewsheds. He was inspired to create the map after seeing Esri's Campus Blue Lights map, which uses viewsheds to show where the beacons on emergency telephones can be seen on a university campus.

William's Viewshed map uses turf.js to show where lines of sight intersect with building polygons on a Mapbox map. The map animates a pair of sunglasses around the Egyptian pyramids. A circular polygon shows the viewshed from the point of view of the sunglasses. The holes in this circular polygon show where the sunglasses' point of view is interrupted by the pyramids and other buildings.

The map is very impressive. It is also a pretty neat demonstration of the power of turf.js for carrying out advanced geospatial analysis with interactive mapping libraries.