Monitoring and Discrimination for Sky Conditions using Multi-temporal Whole Sky Imageries

摘要

Solar radiation is known as the origin of energy on earth surface. Therefore, to estimate the radiation is the indispensable for understanding the radiation and carbon balances in one of the environmental problems. However, the radiation is affected by various sky conditions especially caused by the existence of clouds. Authors have been considering the methodology how to estimate total solar radiation which includes direct and defuse radiations using whole sky images. We have proposed the method to extract the cloud area and estimate cloud cover using Sky Index (SI) which we developed so far. Here, as one of the applications by using multi-temporal whole sky imageries in order to understand the relationship between the solar radiations and sky conditions, we describe the results of sky conditions monitoring and discrimination using the Enhanced Sky Indexes.