COMPARISON OF METHODOLOGIES FOR COMPUTING SKY VIEW FACTOR IN URBAN ENVIRONMENTS
Sky view factor ({Psi}{sub sky}) is used in radiation balance schemes for the partitioning of longwave and shortwave radiation within urban and forest canopies and complex terrain. In the urban environment, ({Psi}{sub sky}) and 1-({Psi}{sub sky}) give a measure of how much radiation penetrates the canopy and how much will be intercepted by the canopy, respectively. As part of the Oct. 2000 URBAN field Experiment in Salt Lake City (Shinn et al., 2001), photographs were taken in the downtown area at ground level shooting upwards using a fisheye lens. Utilizing image analysis and in-house processing software, ({Psi}{sub sky}) was computed for each photograph. Sky view factor was also computed from 3D building databases using the methodology developed by Ratti and Richens (1999). Although photographic methods for obtaining sky view factor are very accurate, they are time consuming to acquire. Commercial 3D building databases are becoming increasingly more available and sky view factor can be computed from them quite easily. In the future, 3D building datasets might be used to readily compute sky view factor for cities and therefore better estimates of the urban climate could be made. Comparisons of the two methods for computing sky view factor are compared in this paper.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 783427
- Report Number(s):
- LA-UR-01-4107; TRN: AH200129%%216
- Resource Relation:
- Conference: Conference title not supplied, Conference location not supplied, Conference dates not supplied; Other Information: PBD: 1 Jul 2001
- Country of Publication:
- United States
- Language:
- English
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