A viewshed accuracy assessment: Comparison of field-derived and computer-derived viewsheds.

摘要

A viewshed is the visible area from an observation location, or what can be seen from a particular vantage point. Viewsheds are calculated using Digital Elevation Models (DEMs) and are used widely by the wireless communications industry, city planners, and military planners. The goal of this research was to determine which combination of DEM interpolation methods and spatial resolutions result in the most accurate DEM and which DEMs produce the most accurate viewsheds. Results indicate the most accurate viewshed was computed from a surface generated from one of the least accurate DEMs (inverse distance weighted at 10 meter spatial resolution). DEM-derived viewsheds vary by as little as 60 percent and as much as 116 percent from field-derived calculations. The variation of the computer-derived viewshed always under predicted the visible area. This research highlights some limitations in the viewshed calculation and serves as a caution to users of viewsheds computed from commercial geographic information system software.