Automatic Delineation of Sky View in Urban Canyons by 3-Dimensional GIS

Accurate delineation of sky view and determination of view-factors in urban canyons is crucial parameter used to characterize radiation properties on urban areas and to express the relationship between the visible area of the sky and the portion of the sky covered by buildings viewed from a specific point of observation. However, to date, most sky view and view-factor calculation endeavors have been done manually and by high cost-equipment methods. As a mean to resolve this problem, this paper presents the use of 3-dimensional Geographic Information System (GIS) for simulating a spatial representation of urban canyons obstructions to sky vault automatically in real-time, in place of many other high cost-equipment methods for delineating sky view and determining view factor, while allowing an automatic delineation of urban canyon geometry. Furthermore, this tool can simulate the current constellation status of positioning-satellite like Global Positioning System (GPS), and evaluate the satellite-based positioning environment concern to signal-shading problem.