Simple Calculator
Choose a standard geometry and enter its dimensions.
Show Formula
Spatial / GIS Calculator
Calculate the solid angle subtended by a 3D triangle or planar polygon from an observer.
About & Methods
This tool calculates the solid angle subtended by standard geometric targets or by an observer-target configuration in three dimensions. WGS84 geographic coordinates are converted to ECEF and then to an observer-centered local ENU frame before calculation.
Scientific scope and limitations
Version 1.0 supports arbitrary 3D triangles and planar or approximately planar simple polygons without holes. “3D visibility” refers to geometric angular extent; terrain viewshed, external occlusion, atmospheric visibility, and DEM analysis are outside this release.
Privacy and map use
Calculations, coordinate transformations, GeoJSON parsing, and exports run in the browser. The application does not send calculation geometry to a computation server. When the optional geographic basemap is displayed, the browser requests map tiles from OpenStreetMap.