视域（viewsheds）原本是指在视野范围内区域，在建筑或艺术领域中，意指从某一特定地点可以看到的地理区域或地区特色。

1. ↑ 艺术与建筑索引典—视域 于2011 年4 月11 日查阅

A viewshed is the geographical area that is visible from a location. It includes all surrounding points that are in line-of-sight with that location and excludes points that are beyond the horizon or obstructed by terrain and other features (e.g., buildings, trees). Conversely, it can also refer to area from which an object can be seen. A viewshed is not necessarily "visible" to humans; the same concept is used in radio communications to indicate where a specific combination of transmitter, antenna, and terrain allow reception of signal.