The Experts below are selected from a list of 25212 Experts worldwide ranked by ideXlab platform
Valeriy Kovalskyy - One of the best experts on this subject based on the ideXlab platform.
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correction to optimal Solar Geometry definition for global long term landsat time series bidirectional reflectance normalization
IEEE Transactions on Geoscience and Remote Sensing, 2018Co-Authors: Hankui K Zhang, David P Roy, Valeriy KovalskyyAbstract:The following typographical errors are present in the right-hand side of the following equation of the paper [1] :
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Optimal Solar Geometry Definition for Global Long-Term Landsat Time-Series Bidirectional Reflectance Normalization
IEEE Transactions on Geoscience and Remote Sensing, 2016Co-Authors: Hankui K Zhang, Valeriy KovalskyyAbstract:The systematic generation of global Landsat time-series products has been advocated, and studies have suggested the need to minimize Landsat reflectance anisotropy effects. Considering a global year of non-Antarctic Landsat 5 and 7 acquisitions, the scene center Solar zenith varied from 22.14° to 89.71°, with a mean of 43.23°. However, a Solar zenith angle definition suitable for generation of global bidirectional reflectance normalized Landsat time series has not been considered. In this paper, a Solar zenith optimal definition is developed in terms of the following criteria: i) ensuring that it can be modeled for any location and date; ii) ensuring that it is constant or smoothly changing with respect to space and time and has global annual variation no greater than the variation in the observed Landsat Solar zenith angles $(\theta_{s})$ ; and iii) minimizing the differences between $\theta_{s}$ and the Solar zenith angle used for normalization. Global coverage Landsat data are used to evaluate four Solar zenith angle definitions, namely, fixed Solar zenith angles, i.e., $(\theta_{\mathrm{fixed}})$ , the Solar zenith at local Solar noon, i.e., $(\theta_{\mathrm{Solar\ noon}})$ , the Solar zenith at the global mean Landsat overpass time, i.e., $(\theta_{\mathrm{mean\ overpass\ time}})$ , and the Solar zenith at a latitude-varying local time parameterized by a polynomial function of latitude, i.e., $(\theta_{\mathrm{poly\ overpass\ time}})$ , that effectively provides a model of $\theta_{s}$ . The optimal definition for global and long time-series Landsat bidirectional reflectance normalization is $(\theta_{\mathrm{poly\ overpass\ time}})$ . The polynomial coefficients are provided so that users may implement Landsat bidirectional reflectance normalization algorithms using this optimal Solar Geometry.
Hankui K Zhang - One of the best experts on this subject based on the ideXlab platform.
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correction to optimal Solar Geometry definition for global long term landsat time series bidirectional reflectance normalization
IEEE Transactions on Geoscience and Remote Sensing, 2018Co-Authors: Hankui K Zhang, David P Roy, Valeriy KovalskyyAbstract:The following typographical errors are present in the right-hand side of the following equation of the paper [1] :
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Optimal Solar Geometry Definition for Global Long-Term Landsat Time-Series Bidirectional Reflectance Normalization
IEEE Transactions on Geoscience and Remote Sensing, 2016Co-Authors: Hankui K Zhang, Valeriy KovalskyyAbstract:The systematic generation of global Landsat time-series products has been advocated, and studies have suggested the need to minimize Landsat reflectance anisotropy effects. Considering a global year of non-Antarctic Landsat 5 and 7 acquisitions, the scene center Solar zenith varied from 22.14° to 89.71°, with a mean of 43.23°. However, a Solar zenith angle definition suitable for generation of global bidirectional reflectance normalized Landsat time series has not been considered. In this paper, a Solar zenith optimal definition is developed in terms of the following criteria: i) ensuring that it can be modeled for any location and date; ii) ensuring that it is constant or smoothly changing with respect to space and time and has global annual variation no greater than the variation in the observed Landsat Solar zenith angles $(\theta_{s})$ ; and iii) minimizing the differences between $\theta_{s}$ and the Solar zenith angle used for normalization. Global coverage Landsat data are used to evaluate four Solar zenith angle definitions, namely, fixed Solar zenith angles, i.e., $(\theta_{\mathrm{fixed}})$ , the Solar zenith at local Solar noon, i.e., $(\theta_{\mathrm{Solar\ noon}})$ , the Solar zenith at the global mean Landsat overpass time, i.e., $(\theta_{\mathrm{mean\ overpass\ time}})$ , and the Solar zenith at a latitude-varying local time parameterized by a polynomial function of latitude, i.e., $(\theta_{\mathrm{poly\ overpass\ time}})$ , that effectively provides a model of $\theta_{s}$ . The optimal definition for global and long time-series Landsat bidirectional reflectance normalization is $(\theta_{\mathrm{poly\ overpass\ time}})$ . The polynomial coefficients are provided so that users may implement Landsat bidirectional reflectance normalization algorithms using this optimal Solar Geometry.
Jose M Cardemil - One of the best experts on this subject based on the ideXlab platform.
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estimating the potential for Solar energy utilization in chile by satellite derived data and ground station measurements
Solar Energy, 2015Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Cristian Cortes, Alan Pino, Marcelo Salgado, John Boland, Jose M CardemilAbstract:Abstract The progress in Solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning more than three years of data, satellite estimations from the recently developed Chile-SR model including three full years of data, and simulations that evaluate the potential for Solar thermal, photovoltaics (PV) and concentrated Solar power (CSP) utilization. The satellite estimation model adapts the Brasil-SR methodology with the combined use of visible and infrared (IR) satellite images, an enhanced treatment for altitude-corrected meteorological variables and an effective cloud cover computations that allows the estimation of the global horizontal and diffuse horizontal irradiation on an hourly basis. Direct normal irradiation (DNI) is computed from the direct horizontal irradiation by applying the Boland–Ridley–Laurent (BRL) model of diffuse fraction and proper Solar Geometry corrections. Comparison of the satellite-derived data with the ground station data shows good agreement and low error levels thus served for model validation. The results indicate that Chile is endowed with one of the highest levels of Solar resource in the world in terms of annual irradiation for large portions of its territory. There is a small decrease in yearly levels of GHI and DNI with latitude that in practice indicate that most of the country shares exceptional conditions for Solar energy. However, coastal regions have a large decrease in both GHI and DNI due to the persistence of seasonal cloud covers with daily cycles. The use of irradiation data from the Chile-SR model for system simulation indicates that Solar fractions over 80% are achievable for residential-sized Solar thermal systems in most of the country, with PV systems yielding between 4.5 and 8 kW h/kWpv, and CSP annual yields of up to 240 GW h/year for a 50 MW parabolic trough plant. These results indicate that the country has the potential for ample utilization of Solar energy conversion technologies in most of its territory when considering annual GHI and DNI, suitable terrain availability and energy (electricity and heat) demand from industrial, commercial and residential activities.
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Solar energy resource assessment in chile satellite estimation and ground station measurements
Renewable Energy, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Cristian Cortes, Alan Pino, Jose M CardemilAbstract:The progress from the last four years in Solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different procedures for the meteorological variables and the effective cloud cover computations that allow estimation of the global horizontal and diffuse irradiation on an hourly basis. Direct normal irradiation is computed by applying proper Solar Geometry corrections to the direct horizontal irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest Solar resources in the world.
Rodrigo Escobar - One of the best experts on this subject based on the ideXlab platform.
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estimating the potential for Solar energy utilization in chile by satellite derived data and ground station measurements
Solar Energy, 2015Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Cristian Cortes, Alan Pino, Marcelo Salgado, John Boland, Jose M CardemilAbstract:Abstract The progress in Solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning more than three years of data, satellite estimations from the recently developed Chile-SR model including three full years of data, and simulations that evaluate the potential for Solar thermal, photovoltaics (PV) and concentrated Solar power (CSP) utilization. The satellite estimation model adapts the Brasil-SR methodology with the combined use of visible and infrared (IR) satellite images, an enhanced treatment for altitude-corrected meteorological variables and an effective cloud cover computations that allows the estimation of the global horizontal and diffuse horizontal irradiation on an hourly basis. Direct normal irradiation (DNI) is computed from the direct horizontal irradiation by applying the Boland–Ridley–Laurent (BRL) model of diffuse fraction and proper Solar Geometry corrections. Comparison of the satellite-derived data with the ground station data shows good agreement and low error levels thus served for model validation. The results indicate that Chile is endowed with one of the highest levels of Solar resource in the world in terms of annual irradiation for large portions of its territory. There is a small decrease in yearly levels of GHI and DNI with latitude that in practice indicate that most of the country shares exceptional conditions for Solar energy. However, coastal regions have a large decrease in both GHI and DNI due to the persistence of seasonal cloud covers with daily cycles. The use of irradiation data from the Chile-SR model for system simulation indicates that Solar fractions over 80% are achievable for residential-sized Solar thermal systems in most of the country, with PV systems yielding between 4.5 and 8 kW h/kWpv, and CSP annual yields of up to 240 GW h/year for a 50 MW parabolic trough plant. These results indicate that the country has the potential for ample utilization of Solar energy conversion technologies in most of its territory when considering annual GHI and DNI, suitable terrain availability and energy (electricity and heat) demand from industrial, commercial and residential activities.
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Solar energy resource assessment in chile satellite estimation and ground station measurements
Renewable Energy, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Cristian Cortes, Alan Pino, Jose M CardemilAbstract:The progress from the last four years in Solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different procedures for the meteorological variables and the effective cloud cover computations that allow estimation of the global horizontal and diffuse irradiation on an hourly basis. Direct normal irradiation is computed by applying proper Solar Geometry corrections to the direct horizontal irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest Solar resources in the world.
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Solar energy resource assessment in chile satellite estimation and ground station measurement
Energy Procedia, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Alberto Ortega, Cristian E Cortes, Alan Pinot, John BolandAbstract:Abstract The progress from the last four years in Solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different treatments for the meteorological variables and the effective cloud cover computations which allow estimation of the global horizontal irradiation on an hourly basis. The BRL model of diffuse radiation is then applied in order to estimate the diffuse fraction and diffuse irradiation, from which the Direct horizontal irradiation is then computed. Direct normal irradiation is computed by applying proper Solar Geometry corrections to the direct horizontal irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest Solar resources in the world, although the resource variability is higher than previously thought.
John Boland - One of the best experts on this subject based on the ideXlab platform.
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estimating the potential for Solar energy utilization in chile by satellite derived data and ground station measurements
Solar Energy, 2015Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Cristian Cortes, Alan Pino, Marcelo Salgado, John Boland, Jose M CardemilAbstract:Abstract The progress in Solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning more than three years of data, satellite estimations from the recently developed Chile-SR model including three full years of data, and simulations that evaluate the potential for Solar thermal, photovoltaics (PV) and concentrated Solar power (CSP) utilization. The satellite estimation model adapts the Brasil-SR methodology with the combined use of visible and infrared (IR) satellite images, an enhanced treatment for altitude-corrected meteorological variables and an effective cloud cover computations that allows the estimation of the global horizontal and diffuse horizontal irradiation on an hourly basis. Direct normal irradiation (DNI) is computed from the direct horizontal irradiation by applying the Boland–Ridley–Laurent (BRL) model of diffuse fraction and proper Solar Geometry corrections. Comparison of the satellite-derived data with the ground station data shows good agreement and low error levels thus served for model validation. The results indicate that Chile is endowed with one of the highest levels of Solar resource in the world in terms of annual irradiation for large portions of its territory. There is a small decrease in yearly levels of GHI and DNI with latitude that in practice indicate that most of the country shares exceptional conditions for Solar energy. However, coastal regions have a large decrease in both GHI and DNI due to the persistence of seasonal cloud covers with daily cycles. The use of irradiation data from the Chile-SR model for system simulation indicates that Solar fractions over 80% are achievable for residential-sized Solar thermal systems in most of the country, with PV systems yielding between 4.5 and 8 kW h/kWpv, and CSP annual yields of up to 240 GW h/year for a 50 MW parabolic trough plant. These results indicate that the country has the potential for ample utilization of Solar energy conversion technologies in most of its territory when considering annual GHI and DNI, suitable terrain availability and energy (electricity and heat) demand from industrial, commercial and residential activities.
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Solar energy resource assessment in chile satellite estimation and ground station measurement
Energy Procedia, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Alberto Ortega, Cristian E Cortes, Alan Pinot, John BolandAbstract:Abstract The progress from the last four years in Solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different treatments for the meteorological variables and the effective cloud cover computations which allow estimation of the global horizontal irradiation on an hourly basis. The BRL model of diffuse radiation is then applied in order to estimate the diffuse fraction and diffuse irradiation, from which the Direct horizontal irradiation is then computed. Direct normal irradiation is computed by applying proper Solar Geometry corrections to the direct horizontal irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest Solar resources in the world, although the resource variability is higher than previously thought.
