Three-dimensional cloud volume reconstruction from the Multi-angle Imaging SpectroRadiometer

Cloud volume reconstruction;Ray casting;Remote sensing;Multi-angle Imaging SpectroRadiometer (MISR)

Lee, Byungsuk ; Di Girolamo ; Larry

关键词: Cloud volume reconstruction;    Ray casting;    Remote sensing;    Multi-angle Imaging SpectroRadiometer (MISR);   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/99363/LEE-THESIS-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Clouds continue to contribute the largest uncertainty to estimates and interpretations of the Earth's energy budget, and their representation in climate models has been recognized for decades as a dominant source of uncertainty in climate change projections. It has been suggested that understanding the 3-D structure of cloud would lead to better understanding of the Earth's radiative and latent fluxes. Indeed, knowing cloud 3-D geometry could lead to: 1) improving our understanding of cloud microphysical properties and processes, and 2) improving our knowledge of the radiative effects of cloud on the Earth's energy budget.The Multi-angle Imaging SpectroRadiometer (MISR) is on board the Terra satellite, in its 17th year of operation as of 2017. MISR provides nine views of the same scene that allow scientists to visualize the 3-D structure of observed clouds to a certain extent. Taking advantage of such multi-angle characteristic, this project aims to reconstruct cloud volumes from MISR data. The reconstruction domain is defined such that it takes into account the curvature of the Earth’s ellipsoidal surface. The input satellite images used are the Radiometric Camera-by-camera Cloud Masks at 1.1 km resolution developed by the MISR science team, and custom cloud masks at 275 m resolution developed from MISR RGB images in this project. Due to the time difference between each camera view angle, wind correction is performed on the input cloud masks. For the reconstruction method, “ray casting” algorithms that fully account for the instrument's geometric properties are developed. The reconstruction results are presented for three hand-picked MISR cloud scenes. Strengths and limitations of the reconstruction method are explored, and the outlook for the use of the reconstruction results are discussed.