Scale Model Measurements for a Daylighting Photometric Data Base

We present initial results of a study to produce a high-precision photometric reference data base using scale model photometry and computational daylighting prediction tools. For this study the SUPERLITE computer code was used. We illustrate the importance and difficulty of fine-tuning the scale model experimental set-up and measurement procedures to produce highly precise results. We discuss the advantage of separating the direct component of illumination from the internal reflected component as an aid to understanding discrepancies between measurements and calculations. We use results of the study to suggest the circumstances in which calculation procedures should be used to generate the references, and those in which the precise scale model photometry is the recommended technique. Further research directions in the field are described.