CBE Research Portal

May 15, 2019

Measurement and Simulation of Circadian Lighting

Completed in 2016.

The human ocular system has two functions. While the most well-known function is to facilitate vision, a growing body of research demonstrates its role in resetting the internal body clock to synchronize with the 24-hour daily cycle. Most research on circadian rhythms is performed in controlled laboratory environments. Lighting professionals increasingly appreciate the influence of light on human health and wellbeing. A holistic approach to design necessitates consideration for both visual and non-visual aspects of lighting. There are established methods for measuring, simulating, and analyzing the luminous environment for photopic responses, but very few methods and tools exist to measure or simulate the circadian light. In the measurement part of this research, tristimulus colour calibration procedures for high dynamic range photography are developed to measure circadian lighting. In the simulation part, a multispectral circadian lighting simulation tool named Lark Spectral Lighting, is developed in Grasshoper/Rhino environment, the simulation engine is Radiance; and it is provided as an open source and freely available tool. The objective is to make circadian lighting analysis more accessible to architects, lighting designers, researchers, and other interested parties.