USING SATELLITE DATA TO PREDICT ZENITH LUMINANCE IN HONG KONG

摘要

This paper presents a method to predict hourly zenith luminance by cloud index n derived from satellite data. This study first classifies three sky conditions by cloud index: n > 0.39. 0.14 ≤ n≤ 0.39 and n < 0.14, corresponding to overcast, partly cloudy and clear skies, more specifically to sky 1, sky 8 and sky 13 of the "Hong Kong Representative Sky". Hourly zenith luminance then is derived by relative standard overcast sky zenith luminance and relative standard clear sky zenith luminance determined by cloud index. The MBE and the RMSE are 0,49 kcd/m~2 and 3,37 kcd/m~2 respectively.