The lineage of the line: space syntax parameters from the analysis of urban DEMs

A number of shortcomings of spacesyntax -- a well-known technique of urban analysis -- were recently discussed in the scientific literature. They are mostly traceable to the reliance in space syntax on the 'axial map': a simplified line-of-sight description of the city, which is then analysed based on its topology. This paper explores how another type of urban representations -- namely the urban digital elevation model (DEM), a raster map which stores building heights -- could prove helpful in providing complementary information to space syntax. Although the use of DEMs is common in the geosciences, their application in urban studies is more recent and shows promise. This paper presents several analysis algorithms to derive urban lines of sight, viewsheds, travelling time maps, and simulations based on cellular automata. The relevance of the approach is discussed, suggesting that it could effectively complement traditional space syntax in the coming years.