scholarly journals A Three-Dimensional Radiation Transfer Model to Evaluate Performance of Compound Parabolic Concentrator-Based Photovoltaic Systems

Energies ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 896 ◽  
Author(s):  
Jingjing Tang ◽  
Yamei Yu ◽  
Runsheng Tang
Keyword(s):  
Radiation Transfer ◽  
Three Dimensional ◽  
Transfer Model ◽  
Photovoltaic Systems ◽  
Compound Parabolic Concentrator ◽  
Radiation Transfer Model

scholarly journals Influence of clouds on the spectral actinic flux density in the lower troposphere (INSPECTRO): overview of the field campaigns

2008 ◽  
Vol 8 (6) ◽  
pp. 1789-1812 ◽  
Author(s):  
S. Thiel ◽  
L. Ammannato ◽  
A. Bais ◽  
B. Bandy ◽  
M. Blumthaler ◽  
...  
Keyword(s):  
Flux Density ◽  
Radiation Field ◽  
Radiation Transfer ◽  
Three Dimensional ◽  
Transfer Model ◽  
Model Calculations ◽  
Actinic Flux ◽  
Airborne Measurements ◽  
Actinic Radiation ◽  
Radiation Transfer Model

Abstract. Ultraviolet radiation is the key factor driving tropospheric photochemistry. It is strongly modulated by clouds and aerosols. A quantitative understanding of the radiation field and its effect on photochemistry is thus only possible with a detailed knowledge of the interaction between clouds and radiation. The overall objective of the project INSPECTRO was the characterization of the three-dimensional actinic radiation field under cloudy conditions. This was achieved during two measurement campaigns in Norfolk (East Anglia, UK) and Lower Bavaria (Germany) combining space-based, aircraft and ground-based measurements as well as simulations with the one-dimensional radiation transfer model UVSPEC and the three-dimensional radiation transfer model MYSTIC. During both campaigns the spectral actinic flux density was measured at several locations at ground level and in the air by up to four different aircraft. This allows the comparison of measured and simulated actinic radiation profiles. In addition satellite data were used to complete the information of the three dimensional input data set for the simulation. A three-dimensional simulation of actinic flux density data under cloudy sky conditions requires a realistic simulation of the cloud field to be used as an input for the 3-D radiation transfer model calculations. Two different approaches were applied, to derive high- and low-resolution data sets, with a grid resolution of about 100 m and 1 km, respectively. The results of the measured and simulated radiation profiles as well as the results of the ground based measurements are presented in terms of photolysis rate profiles for ozone and nitrogen dioxide. During both campaigns all spectroradiometer systems agreed within ±10% if mandatory corrections e.g. stray light correction were applied. Stability changes of the systems were below 5% over the 4 week campaign periods and negligible over a few days. The J(O1D) data of the single monochromator systems can be evaluated for zenith angles less than 70°, which was satisfied by nearly all airborne measurements during both campaigns. The comparison of the airborne measurements with corresponding simulations is presented for the total, downward and upward flux during selected clear sky periods of both campaigns. The compliance between the measured (from three aircraft) and simulated downward and total flux profiles lies in the range of ±15%.

scholarly journals Influence of clouds on the spectral actinic flux density in the lower troposphere (INSPECTRO): overview of the field campaigns

2007 ◽  
Vol 7 (5) ◽  
pp. 13417-13473
Author(s):  
S. Thiel ◽  
L. Ammannato ◽  
A. Bais ◽  
B. Bandy ◽  
M. Blumthaler ◽  
...  
Keyword(s):  
Flux Density ◽  
Radiation Field ◽  
Radiation Transfer ◽  
Three Dimensional ◽  
Transfer Model ◽  
Model Calculations ◽  
Actinic Flux ◽  
Airborne Measurements ◽  
Actinic Radiation ◽  
Radiation Transfer Model

Abstract. Ultraviolet radiation is the key factor driving tropospheric photochemistry. It is strongly modulated by clouds and aerosols. A quantitative understanding of the radiation field and its effect on photochemistry is thus only possible with a detailed knowledge of the interaction between clouds and radiation. The overall objective of the project INSPECTRO was the characterization of the three-dimensional actinic radiation field under cloudy conditions. This was achieved during two measurement campaigns in Norfolk (East Anglia, UK) and Lower Bavaria (Germany) combining space-based, aircraft and ground-based measurements as well as simulations with the one-dimensional radiation transfer model UVSPEC and the three-dimensional radiation transfer model MYSTIC. During both campaigns the spectral actinic flux density was measured at several locations at ground level and in the air by up to four different aircraft. This allows the comparison of measured and simulated actinic radiation profiles. In addition satellite data were used to complete the information of the three dimensional input data set for the simulation. A three-dimensional simulation of actinic flux density data under cloudy sky conditions requires a realistic simulation of the cloud field to be used as an input for the 3-D radiation transfer model calculations. Two different approaches were applied, to derive high- and low-resolution data sets, with a grid resolution of about 100 m and 1 km, respectively. The results of the measured and simulated radiation profiles as well as the results of the ground based measurements are presented in terms of photolysis rate profiles for ozone and nitrogen dioxide. During both campaigns all spectroradiometer systems agreed within ±10% if mandatory corrections e.g. stray light correction were applied. Stability changes of the systems were below 5% over the 4 week campaign periods and negligible over a few days. The J(O1D) data of the single monochromator systems can be evaluated for zenith angles less than 70°, which was satisfied by nearly all airborne measurements during both campaigns. The comparison of the airborne measurements with corresponding simulations is presented for the total, downward and upward flux during selected clear sky periods of both campaigns. The compliance between the measured (from three aircraft) and simulated downward and total flux profiles lies in the range of ±15%.

scholarly journals Accelerated RAPID Model Using Heterogeneous Porous Objects

2018 ◽  
Vol 10 (8) ◽  
pp. 1264 ◽  
Author(s):  
Huaguo Huang
Keyword(s):  
Three Dimensional ◽  
Computation Time ◽  
Single Scattering ◽  
Projection Algorithm ◽  
Forest Plot ◽  
Transfer Model ◽  
Bidirectional Reflectance Factor ◽  
Reflectance Factor ◽  
Radiation Transfer Model ◽  
Porous Object

To enhance the capability of three-dimensional (3D) radiative transfer models at the kilometer scale (km-scale), the radiosity applicable to porous individual objects (RAPID) model has been upgraded to RAPID3. The major innovation is that the homogeneous porous object concept (HOMOBJ) used for a tree crown scale is extended to a heterogeneous porous object (HETOBJ) for a forest plot scale. Correspondingly, the radiosity-graphics-combined method has been extended from HOMOBJ to HETOBJ, including the random dynamic projection algorithm, the updated modules of view factors, the single scattering estimation, the multiple scattering solutions, and the bidirectional reflectance factor (BRF) calculations. Five cases of the third radiation transfer model intercomparison (RAMI-3) have been used to verify RAPID3 by the RAMI-3 online checker. Seven scenes with different degrees of topography (valleys and hills) at 500 m size have also been simulated. Using a personal computer (CPU 2.5 GHz, memory 4 GB), the computation time of BRF at 500 m is only approximately 13 min per scene. The mean root mean square error is 0.015. RAPID3 simulated the enhanced contrast of BRF between backward and forward directions due to topography. RAPID3 has been integrated into the free RAPID platform, which should be very useful for the remote sensing community. In addition, the HETOBJ concept may also be useful for the speedup of ray tracing models.

scholarly journals Radiative transfer model of the dust structures of CRL 2688

2011 ◽  
Vol 7 (S283) ◽  
pp. 520-521
Author(s):  
Dejan Vinković ◽  
Bruce Balick
Keyword(s):  
Energy Distribution ◽  
Radiation Transfer ◽  
Spectral Energy Distribution ◽  
Polar Axis ◽  
Radiative Transfer Model ◽  
Spectral Energy ◽  
Transfer Model ◽  
Giant Star ◽  
Basic Features ◽  
Radiation Transfer Model

AbstractNew Hubble images of the reflection nebula CRL 2688 from 0.6 to 1.6μm reveal significant variations of color and opacity in the distribution of scattered starlight. We have constructed a detailed radiation-transfer model consisting principally of an optically thick equatorial disk-like structure; bipolar lobes with density enhancements along the polar axis and at the base of lobes; an optically thin extended envelope containing spherical density-enhanced shells to mimic the outer rings of CRL 2688; and a pair of near-stellar caps that collimate and redden the dispersing starlight near its source. Our model nicely reproduces all of the basic features detected in the HST images, including the famous searchlights and arcs, as well as the measured spectral energy distribution (“SED”) of CRL 2688. Assuming a distance of 420 pc we estimate the light originates in a giant star with a temperature T ~ 7000 K and a luminosity L = 5500 ± 1100 L⊙.

scholarly journals Validation of the New Algorithm for Rain Rate Retrieval from AMSR2 Data Using TMI Rain Rate Product

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Elizaveta Zabolotskikh ◽  
Bertrand Chapron
Keyword(s):  
Rain Rate ◽  
Radiation Transfer ◽  
Liquid Water Content ◽  
Transfer Model ◽  
Ice Clouds ◽  
Brightness Temperatures ◽  
X Band ◽  
Microwave Sounding ◽  
Radiation Transfer Model ◽  
Rain Measurement

A new algorithm is derived for rain rate (RR) estimation from Advanced Microwave Sounding Radiometer 2 (AMSR2) measurements taken at 6.9, 7.3, and 10.65 GHz. The algorithm is based on the numerical simulation of brightness temperatures (TB) for AMSR2 lower frequency channels, using a simplified radiation transfer model. Simultaneous meteorological and hydrological observations, supplemented with modeled values of cloud liquid water content and rain rate values, are used for the calculation of an ensemble of AMSR2TBs and RRs. Ice clouds are not taken into account. AMSR2 brightness temperature differences at C- and X-band channels are then used as inputs to train a neural network (NN) function for RR retrieval. Validation is performed against Tropical Rain Measurement Mission (TRMM) Microwave Instrument (TMI) RR products. For colocated AMSR2-TMI measurements, obtained within 10 min intervals, errors are about 1 mm/h. The new algorithm is applicable for RR estimation up to 20 mm/h. ForRR<2 mm/h the retrieval error is 0.3 mm/h. ForRR>10 mm/h the algorithm significantly underestimates TMI RR.

Global vertically resolved aerosol direct radiation effect from three years of CALIOP data using the FORTH radiation transfer model

2019 ◽  
Vol 224 ◽  
pp. 138-156 ◽  
Author(s):  
M.B. Korras-Carraca ◽  
V. Pappas ◽  
N. Hatzianastassiou ◽  
I. Vardavas ◽  
C. Matsoukas
Keyword(s):  
Radiation Effect ◽  
Radiation Transfer ◽  
Transfer Model ◽  
Direct Radiation ◽  
Radiation Transfer Model
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