Efficient Data Structure and Highly Scalable Algorithm for Total-Viewshed Computation

This paper presents an efficient and highly scalable algorithm, designed from scratch, to calculate total-viewshed in large high-resolution digital elevation models (DEMs) without restrictions as to whether or not the observer is linked to the ground. The keys to the high efficiency of the proposed method are: 1) the selection of a reliable sampling to represent the subareas of study; 2) the use of a compact and stable data structure to store the calculated data; and 3) the high reutilization of data and calculation between the large number of viewpoints. The obtained results demonstrate that the proposed algorithm is the fastest over the most commonly used GIS-software showing very similar numerical accuracy.