Quantitative study of reflection of sunlight by a glass curtain wall resulting in a visual masking effect.

Because of the complexity of the shapes of the structures of buildings, the glass curtain walls of such buildings have different geometries; some of these glass curtain walls have high reflectivity and can strongly focus incident solar light. Under ideal conditions, the solar radiation flux incident onto the glass curtain wall and the solar flux reflected from the glass curtain wall can be theoretically determined. When exposed to an intense light source, human eyes exhibit a visual masking effect when processing an image; the resulting noise level and signal-to-noise ratio in the image are studied. Using field measurements to measure the reflected sunlight of two types of glass curtain walls, the energy distributions of the light reflected from these two different glass curtain walls are determined. This paper focuses on analysis of the experimental results and the cause of the visual masking effect due to the reflection of sunlight from a glass curtain wall and on the method of quantitative calculation of the visual masking effect.