Application of photogrammetry in lighting calculations for obstructed interiors

Previous work has investigated light loss and illuminance distribution in obstructed interiors and put forward the use of 'standard obstructions' as a tool for classification of obstruction. Obstructions may be described for light loss purposes by the ratio of their vertical surface area to the floor area of the interior (VFR), which in practice must be either calculated or estimated. These can be dificult processes to apply to obstruction configurations other than simple rectilinear objects such as standard obstructions. This paper introduces photogrammetry as a tool for modelling obstructions and indicates potential uses of the method in lighting. Two case studies demonstrate the applicability of photogrammetry to modelling obstructions and hence lighting loss. The results confirm that this technology will accelerate the incorporation the effect of obstructions in lighting analysis and design.