新型人工天空半球内表面亮度分布的理论

Theory about the Brightness Distribution over the Inside Surface of New-Style Artificial Sky Hemisphere

针对旧式人工天空半球内表面亮度分布不合理的现象 ,提出一种新型人工天空半球的构造方法 ,并从理论上加以论证 .在新型人工天空半球内 ,用均匀扩散透射材料形成环形散射光源 ,从天顶到地平线依次贴上反光系数递减的材料 ,可使人工天空半球内表面亮度分布与全阴天的真实天空亮度分布一致 .这对于改进现有人工天空半球的亮度分布 ,提高模型测量采光系数的真实性和准确性 ,以及模拟不同地区气候散射光环境都有实际意义 .

Directing against the irrational practice of the brightness over the inside surface of old style sky hemisphere, the method is advanced for constructing a new style one which is then demonstrated theoretically. Circularly scattering light source is formed by evenly diffusive and transmitted material within this new style sky hemisphere. The sticking of meterial with decreasing reflectivity from zenith to ground line in proper sequence will make the brightness distribution over the inside surface of sky hemisphere to agree with the brightness distribution of true sky during cloudy day. This is of practical significance to the improvement of brightness distribution of the sky hemisphere now available, and to the promotion of realness and correctness of measuring lighting factor by model, and to the simulation of scattering light environment in different regions and climates.