A comparison between two DEM products to calculate a visibility analysis for military operations using FOSSGIS

Abstract

Visibility analysis, commonly known as viewshed, is a valuable function in any geographic information system (GIS) and is a critical tool used for many applications, including the military, for representing the overall visibility and surface characteristics of the terrain. The first step to perform a visibility analysis is selecting the digital elevation model (DEM). This study conducted a comparative viewshed analysis, utilising the TanDEM-X 90m and the SRTM 30m DEM products to determine if the lower resolution DEM is suitable to deliver accurate and reliable viewshed analysis results for military purposes. Strategically placed observer points were used to calculate the viewshed analysis and determine if specific target areas (military bases) are visible or not. It was interesting to note that all military bases were either visible or not visible from all observer point locations for both DEMs utilised, however it is unavoidable that the accuracy of a visibility analysis is influenced by the quality of the elevation data source.