K. Blennow, SKY VIEW FACTORS FROM HIGH-RESOLUTION SCANNED FISH-EYE LENS PHOTOGRAPHIC NEGATIVES, Journal of atmospheric and oceanic technology, 12(6), 1995, pp. 1357-1362
A computerized method for calculating the sky view factor from fish-ey
e lens photographic negatives is presented. The images are scanned and
stored on CD ROM, each CD holding 100 images. The images on be retrie
ved at very high resolutions of up to 2048 X 3072 pixels for one 24 mm
X 36 mm negative. The calculations include corrections for lens proje
ction distortion and restrictions in field of view. They are compared
to standard methods of calculating the sky view factor. For applicatio
ns of the sky view factor where the effective infrared radiation is of
interest, a method to account for zenith angular variation in atmosph
eric transmissivity to infrared radiation is presented.