• Arnfield, A. J., and Grimmond C. S. B. , 1998: Canyon geometry, the urban fabric and nocturnal cooling: A simulation approach. Phys. Geogr, 11 , 209239.

    • Search Google Scholar
    • Export Citation
  • Bärring, L., Mattson J. O. , and Lindqvist S. , 1985: Canyon geometry, street temperatures and urban heat island in Malmo, Sweden. J. Climatol, 5 , 433444.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bishop, C. M., 1995: Neural Networks for Pattern Recognition. Oxford University Press, 482 pp.

  • Blennow, K., 1995: Sky view factors from high-resolution scanned fish-eye lens photographic negatives. J. Atmos. Oceanic Technol, 12 , 13571362.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Blennow, K., and Persson P. , 1998: Modelling local-scale frost variations using mobile temperature measurements with a GIS. Agric. For. Meteor, 89 , 5971.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cannon, A. J., and McKendry I. G. , 2002: A graphical sensitivity analysis for statistical climate models: Application to Indian monsoon rainfall prediction by artificial neural networks and multiple linear regression models. Int. J. Climatol, 22 , 16871708.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chapman, L., Thornes J. E. , and Bradley A. V. , 2001a: Modelling of road surface temperature from a geographical parameter database. Part 2: Numerical. Meteor. Appl, 8 , 421436.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chapman, L., Thornes J. E. , and Bradley A. V. , 2001b: Rapid determination of canyon geometry parameters for use in surface radiation budgets. Theor. Appl. Climatol, 69 , 8189.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chapman, L., Thornes J. E. , and Bradley A. V. , 2002: Short communication: Sky-view factor approximation using GPS receivers. Int. J. Climatol, 22 , 615621.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Dodson, A. H., Shardlow P. J. , Hubbard L. C. M. , Elgered G. , and Jarlemark P. O. J. , 1996: Wet tropospheric effects on precise relative GPS height determination. J. Geod, 70 , 188202.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Grimmond, C. S. B., Potter S. K. , Zutter H. N. , and Souch C. , 2001: Rapid methods to estimate sky-view factors applied to urban areas. Int. J. Climatol, 21 , 903913.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Holmer, B., Postgård U. , and Eriksson M. , 2001: Sky view factors in canopies calculated with IDRISI. Theor. Appl. Climatol, 68 , 3340.

  • Johnson, G. T., and Watson I. D. , 1984: The determination of view-factors in urban canyons. J. Appl. Climate Meteor, 23 , 329335.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Karlsson, I. M., 2000: Nocturnal air temperature variations between forest and open areas. J. Appl. Meteor, 39 , 851862.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Leick, A., 1995: GPS Satellite Surveying. 2d ed. John Wiley & Sons, 560 pp.

  • Ni, F., Cavazos T. , Hughes M. K. , Comrie A. C. , and Funkhouser G. , 2002: Cool season precipitation in the southwestern USA since AD1000: Comparison of linear and nonlinear techniques for reconstruction. Int. J. Climatol, 22 , 16451662.

    • Search Google Scholar
    • Export Citation
  • Oke, T. R., 1981: Canyon geometry and the nocturnal urban heat island: Comparison of scale model and field observations. J. Climatol, 1 , 237254.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Postgård, U., and Nunez M. , 2000: Continuous measurements of sky-view factors along roads and their relationship to air and road surface temperature. Road climate variations related to weather and topography. Ph.D. thesis, University of Gothenberg, Sweden.

    • Search Google Scholar
    • Export Citation
  • Sigrist, P., Coppin P. , and Hermy M. , 1999: Impact of forest canopy on quality and accuracy of GPS measurements. Int. J. Remote Sens, 20 , 35953610.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Steyn, D. G., 1980: The calculation of view-factors from fisheye-lens photographs: Research note. J. Atmos. Ocean Sci, 18 , 254258.

  • Steyn, D. G., Hay J. D. , Watson I. D. , and Johnson G. T. , 1986: The determination of sky-view factors in urban environments using video imagery. J. Atmos. Oceanic Technol, 3 , 759764.

    • Crossref
    • Search Google Scholar
    • Export Citation
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Real-Time Sky-View Factor Calculation and Approximation

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  • 1 Entice Technology Ltd., School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
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Abstract

Previously, the acquisition of sky-view factor data for climate studies has been time consuming and dependent on postprocessing. However, advances in technology now mean that techniques using fish-eye imagery can be algorithmically processed in real time to provide an instant calculation of the sky-view factor. Although data collection is often limited due to the need to survey under homogenous overcast skies, vast datasets can now be rapidly assembled for the training of proxy “all weather” techniques. An artificial neural network is used to estimate the sky-view factor using raw global positioning system (GPS) data and is shown to explain over 69% of the variation of the sky-view factor in urban areas.

Corresponding author address: Dr. L. Chapman, Entice Technology Ltd., School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. Email: l.chapman@bham.ac.uk

Abstract

Previously, the acquisition of sky-view factor data for climate studies has been time consuming and dependent on postprocessing. However, advances in technology now mean that techniques using fish-eye imagery can be algorithmically processed in real time to provide an instant calculation of the sky-view factor. Although data collection is often limited due to the need to survey under homogenous overcast skies, vast datasets can now be rapidly assembled for the training of proxy “all weather” techniques. An artificial neural network is used to estimate the sky-view factor using raw global positioning system (GPS) data and is shown to explain over 69% of the variation of the sky-view factor in urban areas.

Corresponding author address: Dr. L. Chapman, Entice Technology Ltd., School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. Email: l.chapman@bham.ac.uk

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