On the accurate estimation of gap fraction during daytime with digital cover photography

Yorum Hwang1, Youngryel Ryu1, Hyungsuk Kimm2, Craig Macfarlane3, Mait Lang4 and Oliver Sonnentag5, (1)Seoul National University, Department of Landscape Architecture and Rural Systems Engineering, Seoul, Korea, Republic of (South), (2)University of Illinois at Urbana-Champaign, Department of Natural Resources and Environmental Sciences, Urbana, United States, (3)CSIRO Land and Water Flagship, Private Bag No. 5, Wembley,WA6917, Australia, (4)Tartu Observatory, 61602 Tõravere, Tartu, Estonia, (5)University of Montreal, Geography, Montreal, QC, Canada