SVF-CDM: Sky View Factor, a Continuous Digital Model for large cities using SVFPy

Abstract

The Sky View Factor (SVF) has been used as an index of dimensionality and complexity reduction in several areas of knowledge to model and qualify the urban environment and the landscape. This article proposes a new method to calculate the Digital Continuous Model of SVF (SVF-CDM) from LiDAR 3D ALS surveys for large cities. The method is described from the perspective of single-point computing and then adapted to a more efficient heuristic computational process called here SVFPy . The SVF-CDM processing was carried out for the entire length of the São Paulo and New York cities, with a spatial resolution of 50 cm and 1.25 ft (38.1 cm), respectively. Method validation was based on comparing a sample of random points, and the median errors were -0.53 (São Paulo) and 1.37 (New York) percentage points. The results indicate that the SVF-CDM has advantages over other digital models and features for urban morphology analysis. Whether visually or through its dimensional and statistical expression, the presented model manages to express the nuances and morphological aspects of the studied areas. In this way, we conclude that we are facing a significant advance for the models of urban studies, not only because it considers the perspective of the pedestrian but also because it is a powerful resource for studies and disciplines related to the urban form without disregarding all its complexity.