scholarly journals OPTICAL POLARIZED EFFECTS FOR QUANTITATIVE REMOTE SENSING

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 593-598
Author(s):  
L. Yan ◽  
Y. Li ◽  
H. Mortimer ◽  
R. Zhang ◽  
J. Peltoniemi ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Linear Polarization ◽  
Rayleigh Scattering ◽  
Weather Conditions ◽  
Degree Of Polarization ◽  
Gradual Change ◽  
Distribution Law ◽  
Solar Altitude ◽  
Quantitative Remote Sensing ◽  
Skylight Polarization

Abstract. Polarization is one of the four basic physical properties of solar radiation. After the solar radiation reaches the surface of these media, it reflects, scatters or refracts, and exhibits different degrees of polarization. We use Rayleigh scattering model to get the simulation results of the sky polarization field. We use polarized fisheye camera to collect the sky polarization image, and calculate the distribution pattern of DOLP (degree of linear polarization) and AOLP (azimuth of linear polarization) of the skylight. The stability and gradual change of the degree of polarization in the zenith direction are verified, and the distribution law and daily change law of the degree of polarization in the sky are obtained. With the increase of the solar altitude angle, the degree of polarization will decrease. We also observed the skylight polarization in different weather conditions.

The Polarization Properties Research of Atmospheric Based on Actual Weather Conditions

2014 ◽  
Vol 556-562 ◽  
pp. 933-936
Author(s):  
Fei Zhang ◽  
Xiao Ping Du ◽  
Shen Wang
Keyword(s):  
Rayleigh Scattering ◽  
Weather Conditions ◽  
Mie Scattering ◽  
New Method ◽  
Degree Of Polarization ◽  
Scattering Angle ◽  
Polarization Characteristics ◽  
Simulation Results

A new method to calculate the polarization properties of the atmosphere by combining the Rayleigh scattering and Mie scattering is proposed in this paper. We inversed the values of the required data by experiment and simulated of the atmosphere polarization characteristics under the same conditions. The simulation results show that the proposed method can accurately describe the variation of the atmosphere polarization properties. Besides, the results show such variation: in the same weather conditions, the degree of polarization is gradually increased while scattering angle is gradually increased as 90°; in the same detect conditions, the degree of polarization decreases with the deteriorating weather conditions.

scholarly journals Skylight Polarization patterns and Animal Orientation

1982 ◽  
Vol 96 (1) ◽  
pp. 69-91 ◽  
Author(s):  
MICHAEL L. BRINES ◽  
JAMES L. GOULD
Keyword(s):  
Rayleigh Scattering ◽  
Polarized Light ◽  
Processing System ◽  
Light Polarization ◽  
Degree Of Polarization ◽  
Atmospheric Conditions ◽  
Apparent Paradox ◽  
Skylight Polarization ◽  
Visible Wavelengths ◽  
Vector Orientation

1. Although many invertebrate animals orient by means of ultraviolet sky-light polarization patterns, existing measurements of these patterns are inadequate for full analysis of the biologically relevant information available from the sky. To fill this gap we have used a precision scanning polarimeter to measure simultaneously the intensity, degree, and direction of vibration (E-vector orientation) of polarized light at 5° intervals over the sky. The resulting sky maps were constructed for u.v. (350 nm) and visible wavelengths (500 and 650 nm) under a variety of atmospheric conditions. 2. Our measurements confirmed that the patterns of radiance and degree of polarization of skylight are highly variable and hence unreliable as orientation cues; but patterns of E-vector orientation are relatively stable and predictable over most of the sky under all but very hazy or overcast conditions. 3. The observed E-vector patterns correspond more closely to predictions based on first order (Rayleigh) scattering at 650 and 500 nm than at 350 nm. This is true both in terms of absolute accuracy and the proportion of the sky with relatively ‘correct’ information. Yet most insects respond to polarization patterns only at u.v. wavelengths. This apparent paradox can perhaps be resolved by assuming that there is no great selective advantage for any particular wavelength when large areas of blue sky are visible, but that under special and difficult conditions ultraviolet has advantages over longer wavelengths. Measurements under partially cloud-covered sky, for instance, or under extensive vegetation, show that both spuriously polarized and unpolarized light resulting from reflexions present more troublesome interference at longer wavelengths than in the u.v. 4. The accuracy of orientation achieved by dancing honey bees appears to be greater than can readily be accounted for by assuming that they use a strictly geometrical or analytical processing system for their orientation to polarized light.

Rayleigh Scattering of Excimer Laser Light from Some Simple Molecules at 193 nm and 248 nm: The Effect of Polarization upon Imaging Diagnostics

1997 ◽  
Vol 51 (7) ◽  
pp. 1012-1016 ◽  
Author(s):  
Wolfgang Reckers ◽  
Yongwei Gu ◽  
Erhard W. Rothe ◽  
Heinrich Voges
Keyword(s):  
Excimer Laser ◽  
Cross Sections ◽  
Linear Polarization ◽  
Rayleigh Scattering ◽  
Polarization State ◽  
Degree Of Polarization ◽  
Important Species ◽  
Pass Through ◽  
Simple Molecules ◽  
193 Nm

Tunable excimer laser beams are increasingly used for imaging of combustion and/or flow systems. We (1) describe the need to use known polarization phenomena in interpreting diagnostics based on Rayleigh scattering (RS); (2) present relative RS cross sections for some important species at the most relevant wavelengths, 193 and 248 nm; and (3) measure the degree of linear polarization and the locking efficiency of the excimer beam, which are important diagnostic parameters that are otherwise difficult to obtain. Laser sheets, whose direction of linear polarization are adjustable, pass through gases. The Rayleigh light goes into intensified charge-coupled dervice (CCD) cameras. We report RS cross sections, normalized to those for N2, at 193 nm for H2, O2, H2O, CO2, and CH4, and at 248 nm for Ar, H2, O2, H2O, CO2, and CH4. Even when these normalized RS cross sections are used, the diagnostics can be very sensitive to the laser beam's polarization state. For example, for CO2, the normalized cross section changes by a factor of 4 with polarization. This usually unwanted sensitivity is greatest when an unmodified tunable excimer laser is used. The degree of polarization of the lasers, as well as their locking efficiency, is derived via RS from the spherical molecules Ar and CH4.

scholarly journals Atmospheric influences on infrared-laser signals used for occultation measurements between Low Earth Orbit satellites

2011 ◽  
Vol 4 (10) ◽  
pp. 2273-2292 ◽  
Author(s):  
S. Schweitzer ◽  
G. Kirchengast ◽  
V. Proschek
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Thermal Radiation ◽  
Rayleigh Scattering ◽  
Infrared Laser ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Wind Speed Profile ◽  
Upper Troposphere ◽  
Trace Species

Abstract. LEO-LEO infrared-laser occultation (LIO) is a new occultation technique between Low Earth Orbit (LEO) satellites, which applies signals in the short wave infrared spectral range (SWIR) within 2 μm to 2.5 μm. It is part of the LEO-LEO microwave and infrared-laser occultation (LMIO) method that enables to retrieve thermodynamic profiles (pressure, temperature, humidity) and altitude levels from microwave signals and profiles of greenhouse gases and further variables such as line-of-sight wind speed from simultaneously measured LIO signals. Due to the novelty of the LMIO method, detailed knowledge of atmospheric influences on LIO signals and of their suitability for accurate trace species retrieval did not yet exist. Here we discuss these influences, assessing effects from refraction, trace species absorption, aerosol extinction and Rayleigh scattering in detail, and addressing clouds, turbulence, wind, scattered solar radiation and terrestrial thermal radiation as well. We show that the influence of refractive defocusing, foreign species absorption, aerosols and turbulence is observable, but can be rendered small to negligible by use of the differential transmission principle with a close frequency spacing of LIO absorption and reference signals within 0.5%. The influences of Rayleigh scattering and terrestrial thermal radiation are found negligible. Cloud-scattered solar radiation can be observable under bright-day conditions, but this influence can be made negligible by a close time spacing (within 5 ms) of interleaved laser-pulse and background signals. Cloud extinction loss generally blocks SWIR signals, except very thin or sub-visible cirrus clouds, which can be addressed by retrieving a cloud layering profile and exploiting it in the trace species retrieval. Wind can have a small influence on the trace species absorption, which can be made negligible by using a simultaneously retrieved or a moderately accurate background wind speed profile. We conclude that the set of SWIR channels proposed for implementing the LMIO method (Kirchengast and Schweitzer, 2011) provides adequate sensitivity to accurately retrieve eight trace species of key importance to climate and atmospheric chemistry (H2O, CO2, 13CO2, C18OO, CH4, N2O, O3, CO) in the upper troposphere/lower stratosphere region outside clouds under all atmospheric conditions. Two further species (HDO, H218O) can be retrieved in the upper troposphere.

scholarly journals Characteristics of solar radiation at Xiaotang, in the northern marginal zone of the Taklimakan Desert

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12373
Author(s):  
Lili Jin ◽  
Sasa Zhou ◽  
Qing He ◽  
Alim Abbas
Keyword(s):  
Solar Radiation ◽  
Scattered Radiation ◽  
Weather Conditions ◽  
Taklimakan Desert ◽  
Observation Data ◽  
Total Radiation ◽  
Direct Radiation ◽  
Northern Margin ◽  
Monthly Total ◽  
Atmospheric Transmittance

The characteristics of solar radiation and the influence of sand and dust on solar radiation in the northern margin of Taklimakan Desert were analyzed using radiation observation data from 2018. The results showed that the annual total radiation, direct radiation, and scattered radiation at Xiaotang were 5,781.8, 2,337.9, and 3,323.8 MJ m−2, respectively. The maximum monthly total radiation, direct radiation, and scattered radiation were observed in July (679.8 MJ m−2), August (317.3 MJ m−2), and May (455.7 MJ m−2), respectively. The aerosol optical depth corresponded well with the scattered radiation, and the maximum value was in May. Further analysis showed a significant correlation between the total radiation and solar height angle under different weather conditions. Under the same solar height angle, total radiation was higher during clear days but lower on sandstorm days. Calculation of atmospheric transmittance showed that the average atmospheric transmittance on a clear day was 0.67; on sand-and-dust days, it was 0.46. When the atmospheric transmittance was 0.5, the increase in scattering radiation by aerosol in the air began to decrease. Probability analysis of radiation indicated the following probabilities of total radiation <500 W m−2 occurring on clear, floating-dust, blowing-sand, and sandstorm days: 67.1%, 76.3%, 76.1%, and 91.8%, respectively. Dust had the greatest influence on direct radiation; the probabilities of direct radiation <200 W m−2occurring on clear, floating-dust, blowing-sand, and sandstorm days were 44.5%, 93.5%, 91.3%, and 100%, respectively, whereas those of scattered radiation <600 W m−2were 100%, 99.1%, 98.1%, and 100%, respectively. Therefore, the presence of dust in the air will reduce scattered radiation.

scholarly journals Identification of solar radiation effect on climatic indicators of the territory of Ukraine

2018 ◽  
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Air Temperature ◽  
Temperature Regime ◽  
Atmospheric Pressure ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Practical Significance ◽  
Statistical Dependence ◽  
Physical Processes

Formulation of the problem. Understanding that solar energy is the main source of the majority of biological, chemical and physical processes on Earth, investigation of its influence on different climatic fields allows us to define the features of its space and hour fluctuations. To define radiation and temperature regime of the territory it is necessary to determine climatic features of the spreading surface, which absorbs and will transform solar energy. Considering the fact that modern climatic changes and their consequences cover all components of the system, today there is a problem of their further study for comprehension of atmospheric processes, modeling weather conditions on different territories depending on the properties. The purpose of the article is to determine interrelations between indexes of solar radiation (the Wolf's number) and air temperature, atmospheric pressure on the territory of Ukraine during 1965-2015, their change in space and time. Methods. Correlative method is one of the main methods of a statistical analysis which allows us to receive correlation coefficients of solar radiation variability indexes, air temperature, atmospheric pressure on the territory of the research. This technique estimates the extent of solar radiation influence on temperature regime of the territory and distribution of atmospheric pressure. Results. Coefficients of correlation, which characterize variability of solar radiation indexes, air temperature and atmospheric pressure on the explored territory have been received by means of statistical correlation analysis method. This technique allows us to estimate the degree and nature of solar radiation influence on a temperature regime of the territory and distribution of atmospheric pressure. It has been defined that direct correlative connection between indexes of solar radiation is characteristic of air temperature and atmospheric pressure fields. Significant statistical dependence between incoming solar radiation on the territory of Ukraine and atmospheric pressure has been noted during the spring and autumn periods mainly at the majority of stations. Between indexes of solar radiation and air temperature the inverse correlative connection in winter will be transformed to a direct connection during the spring and summer periods. Scientific novelty and practical significance. Physical processes, which happen in the atmosphere, are characterized by complex interrelations. For further research it is important to define solar radiation value and the extent of influence on climatic conditions.

scholarly journals Forecasting and Modelling of Solar Radiation for Photovoltaic (PV) Systems

2021 ◽  
Author(s):  
Ines Sansa ◽  
Najiba Mrabet Bellaaj
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
Cloud Cover ◽  
Moving Average ◽  
Arma Model ◽  
Weather Conditions ◽  
Pv Systems ◽  
Auto Regressive ◽  
Micro Grid ◽  
One Year

Solar radiation is characterized by its fluctuation because it depends to different factors such as the day hour, the speed wind, the cloud cover and some other weather conditions. Certainly, this fluctuation can affect the PV power production and then its integration on the electrical micro grid. An accurate forecasting of solar radiation is so important to avoid these problems. In this chapter, the solar radiation is treated as time series and it is predicted using the Auto Regressive and Moving Average (ARMA) model. Based on the solar radiation forecasting results, the photovoltaic (PV) power is then forecasted. The choice of ARMA model has been carried out in order to exploit its own strength. This model is characterized by its flexibility and its ability to extract the useful statistical properties, for time series predictions, it is among the most used models. In this work, ARMA model is used to forecast the solar radiation one year in advance considering the weekly radiation averages. Simulation results have proven the effectiveness of ARMA model to forecast the small solar radiation fluctuations.

scholarly journals Some Effects of Multiple Scattering on the Distribution of Solar Radiation in Snow and Ice

1972 ◽  
Vol 11 (63) ◽  
pp. 357-368 ◽  
Author(s):  
Bruce R. Barkstrom
Keyword(s):  
Solar Radiation ◽  
Multiple Scattering ◽  
Specular Reflection ◽  
Scattering Problem ◽  
Solar Flux ◽  
Isotropic Scattering ◽  
Solar Altitude ◽  
Exponential Decrease ◽  
The Antarctic ◽  
Upward Flux

AbstractMultiple scattering of the solar flux in snow and “bubbly” ice can account for the variable albedo, the non-specular reflection, the non-exponential flux decrease near the surface, and the large upward flux within the medium. The scattering problem has been formulated and solved exactly, assuming isotropic scattering in a plane-parallel, semi-infinite, grey medium. The solution shows a non-exponential flux decrease near the surface and an exponential decrease deep in the medium. For such a medium, the albedo will increase with decreasing solar altitude in a manner which agrees to within one per cent of observed snow albedos in the Antarctic.

Diurnal albedo variation of black spruce and sphagnum–sedge bogs

1976 ◽  
Vol 6 (3) ◽  
pp. 247-252 ◽  
Author(s):  
Erwin R. Berglund ◽  
Arnett C. Mace Jr.
Keyword(s):  
Solar Radiation ◽  
Black Spruce ◽  
Specular Reflection ◽  
Radiation Quality ◽  
Surface Flattening ◽  
Solar Altitude ◽  
Space And Time ◽  
Time Variations ◽  
Dominant Influence

Diurnal albedo relationships were determined for black spruce (Piceamariana (Mill.) B.S.P.) and sphagnum–sedge bogs in northern Minnesota. Two opposing, cart-mounted, Kipp and Zonen pyranometers traversed a tramway to integrate space and time variations of incoming and reflected solar radiation (waveband 0.3–3.0 microns (μ)).The black spruce stand's diurnal albedo was parabolic. Albedo increased with solar altitude to a maximum at 1200 h (7–8%) and then decreased. Greatest within-season variation occurred during June and September. Canopy roughness was the dominant influence on albedo variation and differences.The sphagnum–sedge type diurnal albedo was M-shaped. A minimum albedo between two maxima occurred at 1200 h. Albedos increased from the 1200-h minimum to each maxima as a result of reported surface 'flattening' effects, increased specular reflection, and changes in solar radiation quality. Albedos before the first and after the second maxima were dominated by the microrelief roughness of the sphagnum–sedge hummocks.

scholarly journals Concentrator photovoltaic module architectures with capabilities for capture and conversion of full global solar radiation

2016 ◽  
Vol 113 (51) ◽  
pp. E8210-E8218 ◽  
Author(s):  
Kyu-Tae Lee ◽  
Yuan Yao ◽  
Junwen He ◽  
Brent Fisher ◽  
Xing Sheng ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Flat Plate ◽  
Large Scale ◽  
Experimental Studies ◽  
Weather Conditions ◽  
Global Solar Radiation ◽  
Photovoltaic Module ◽  
Module Design ◽  
Direct Normal Irradiance ◽  
Cost Of Energy

Emerging classes of concentrator photovoltaic (CPV) modules reach efficiencies that are far greater than those of even the highest performance flat-plate PV technologies, with architectures that have the potential to provide the lowest cost of energy in locations with high direct normal irradiance (DNI). A disadvantage is their inability to effectively use diffuse sunlight, thereby constraining widespread geographic deployment and limiting performance even under the most favorable DNI conditions. This study introduces a module design that integrates capabilities in flat-plate PV directly with the most sophisticated CPV technologies, for capture of both direct and diffuse sunlight, thereby achieving efficiency in PV conversion of the global solar radiation. Specific examples of this scheme exploit commodity silicon (Si) cells integrated with two different CPV module designs, where they capture light that is not efficiently directed by the concentrator optics onto large-scale arrays of miniature multijunction (MJ) solar cells that use advanced III–V semiconductor technologies. In this CPV+scheme (“+” denotes the addition of diffuse collector), the Si and MJ cells operate independently on indirect and direct solar radiation, respectively. On-sun experimental studies of CPV+modules at latitudes of 35.9886° N (Durham, NC), 40.1125° N (Bondville, IL), and 38.9072° N (Washington, DC) show improvements in absolute module efficiencies of between 1.02% and 8.45% over values obtained using otherwise similar CPV modules, depending on weather conditions. These concepts have the potential to expand the geographic reach and improve the cost-effectiveness of the highest efficiency forms of PV power generation.

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