RT info:eu-repo/semantics/doctoralThesis
T1 Configuración y metodología para el uso de cámaras de todo cielo en la obtención de parámetros atmosféricos.
A1 Antuña Sánchez, Juan Carlos
A2 Universidad de Valladolid. Escuela de Doctorado
K1 Atmósfera
K1 Radiación solar
K1 Tierra
K1 Atmospheric aerosols
K1 Aerosoles atmosféricos
K1 All-sky cameras
K1 Cámaras de todo cielo
K1 Sky radiance
K1 Radiancia del cielo
K1 2501.08 Óptica Atmosférica
AB Atmospheric aerosols, solid or liquid particles floating in the atmosphere, play an important role in the Earth's climate, since they scatter and absorb part of the solar radiation reaching the Earth. The aerosol properties are usually obtained by measuring the diffuse solar radiation incoming in different directions (sky radiance), which is partially formed by the scattering of aerosols. The sky radiance is usually measured with photometers. A cheaper alternative to these photometers are the all-sky cameras, which capture images of the whole sky. In this doctoral thesis we propose the use of all-sky cameras to retrieve atmospheric parameters like the sky radiance and some aerosol properties, which can be obtained from these radiances.In this work, the ORION application has been developed to calibrate geometrically the all-sky cameras through the position of the stars. These calibrations are essential to locate the pixels of the camera pointing to a specific direction, such as the directions in which the sky radiance will be extracted. An all-sky camera has been geometrically calibrated with ORION, but it also has been configured to capture images in RAW format at different exposure times. The multi-exposure configuration, in addition with a exhaustive characterization of the camera (effective wavelengths, linearity, read noise, etc.), has allowed to obtain a linear high dynamic range image of the sky applying a proposed methodology. The sky radiance is proportional to the linear image obtained, so a relative sky radiance can be obtained with this proposed methodology.Once the relative sky radiances have been obtained with the all-sky camera, they have been used as input parameter in the GRASP (Generalized Retrieval of Atmosphere and Surface Properties) inversion algorithm to obtain some aerosol properties. It has been studied, using synthetic data, what aerosol properties can be derived from the relative sky radiance measured by all-sky cameras. The aerosol properties obtained with real measurements on GRASP have been compared with those independently derived by an AERONET (AErosol RObotic NETwork) photometer.This work concludes that, if the methodologies developed in this doctoral thesis are applied, a properly configured all-sky camera can be used to calculate the sky radiance, at least in a relative way, and these radiances can be also used to retrieve aerosol properties.
YR 2021
FD 2021
LK https://uvadoc.uva.es/handle/10324/60022
UL https://uvadoc.uva.es/handle/10324/60022
LA spa
NO Escuela de Doctorado
DS UVaDOC
RD 20-may-2024