Austria is largely covered by the Alps with its many spectacular summits – but from where can you see them? This question was the driver to build the Alpenblick app that allows one to interactively navigate on a 3D map and get insights on the mountain peak visibility in any location. A click on the map reveals the perspective from that location looking towards the closest summit. The map itself displays an opaque layer on-top which indicates that a mountain peak is visible from that location – the more intense the color the more peaks are visible. The summits are indicated with labels floating above the peak.
This project demonstrates the power of interactive prototyping since the development effort is quite low due to the availability of powerful and easy-to-use components. In the GIS world, this problem can be answered by performing a viewshed analysis which is a common functionality available in GIS tools. Using a publicly available digital elevation model (DEM) in a high resolution the viewshed can be calculated and exported by the software and further visualized in an app. This results in a layer that depicts the visibility from each location within 100 km from an observation height of 1.60 m (which is roughly the eye-height) above ground of significant summits of the Austrian Alps.
This idea was implemented as a web app utilizing the latest technologies, such as CesiumJS for an accurate 3D rendering of the terrain surface. This library has tools to perform geospatial operations that enable the creation and exploration of a 3D scene with only a few lines of code. The data was pre-processed with the powerful and open-source GIS tool QGIS and uses open data (Digitales Geländemodell (DGM) Österreich by Geoland, AlpsOver589m.xls by Eberhard Jurgalski et al.).