Quality Assessment Based Upon Comparison with Models
Many models based on the physics of radiation transfer through the clear atmosphere have been developed (Lacis and Hansen 1974; Atwater and Ball 1978; Hoyt 1978; Bird and Hulstrom 1981a, …
Solar Horizontal Diffuse and Beam Irradiation on Clear Days
There exist a number of models to determine the solar horizontal diffuse irradiation on a clear day (Kondratyev 1969) but they are complex and have very stringent conditions. Similarly, there …
Foreword
Reading the twenty chapters of this book caused me mixed reactions, though all were positive. My responses were shaped by several factors. Although I have maintained a “watching brief’ on …
Modelling the Statistical Properties of Solar Radiation and Proposal of a Technique Based on Boltzmann Statistics
Joaquin Tovar-Pescador 1 Introduction Solar radiation affects all the Earth’s processes related to the environment and plays a fundamental role in the development of human activities. Among these processes, solar …
Radiometer Uncertainty Sources
Sensitivity Functions Combined uncertainties depend on the product of the sensitivity functions (partial derivatives of the response with respect to the measurement equation variables) and error source magnitudes, et. The …
Parameter’s Dependence on the Local Climatology
As we have shown, the distributions and models proposed depend on the local climate. In the case of the Tovar’s model the parameters A1, A2, kt01, kt02, X1, ^2 should …
Conclusions
We urge the reader to remember, as he or she studies the rest of this book, that there are no perfect measurements. However, the field of solar radiometry has critically …
Clear Day Horizontal Beam Irradiation
The clear day horizontal beam irradiation is also defined as that incident on a horizontal surface on a clear day, viz., KT > 0.7. The clear day horizontal beam index …
Preface
Solar radiation data at ground level are important for a wide range of applications in meteorology, engineering, agricultural sciences (particularly for soil physics, agricultural hydrology, crop modeling and estimating crop …
Physical and Statistical Modelling of Solar Radiation
In order to understand and to model the behaviour of solar radiation, two approaches can be used (Festa and Ratto, 1993). a) The first one is called “physical modelling”, and …
Thermal Offsets
Climate research studies of solar radiation instrumentation, such as those made by the Baseline Surface Radiation Network (BSRN) participants, have characterized thermal offsets in thermopile pyranometers with all-black sensors measuring …
Distributions of 1-minute кb Values Conditioned by Optical Air Mass
Figure 3.16 shows the kb frequency distributions for different optical air masses for Armilla (Spain). All the curves present a bimodal appearance, with two well defined maxima. The first maximum, …
Fractal Classification of Typical Meteorological Days from Global Solar Irradiance: Application to Five Sites of Different Climates
Samia Harrouni 1 Introduction To electrify remote areas, the use of solar energy is the best economical and technological solution. The choice of the sites for the installation of photovoltaic …
Correlation Between Clear Day Horizontal Diffuse and Beam Indices
Ever since the publication of the pioneering work by Liu and Jordan (1960) there have been persistent efforts to develop correlations between global, direct and diffuse irradiation. We have previously …
Acknowledgments
A critical part of writing any book is the reviewing process, and the authors and editor are very much obliged to the following researchers who patiently helped them read through …
Stochastic Processes. Stationarity
Stochastic processes concern sequences of events governed by probabilistic laws (Karlin and Taylor 1975). A stochastic process X={X(t), t є T} is a collection of random variables. That is, for …
Geometric, Environmental and Equipment Uncertainty
Additional contributors to the uncertainty of all radiometers include: temperature coefficients, linearity, thermal electromotive forces, and electromagnetic interference. Moreover, the field of view of many pyrheliometers differs from that of …
One-Minute kd Values Distributions Conditioned by the Optical Air Mass
The analysis of the experimental distributions of 1-minute horizontal diffuse irradiation has been carried out following the same approach as for kt and kb. The diffuse component has been analysed …
Solar Radiation
This section reviews the properties of solar radiation on Earth and summaries well-known models which are used to estimate the amount of radiation falling on a tilted plane. Extraterrestrial solar …
Analysis of Solar Irradiation Distribution Types
The analysis of the frequency distribution and distribution type of a particular solar irradiation database are very important parameters in the design of solar irradiation conversion systems. The conversion system …
Solar Radiation Measurement: Progress in Radiometry for Improved Modeling
Christian A. Gueymard and Daryl R. Myers 1 Introduction This chapter is designed to be a concise introduction to modern solar radiometry and how solar radiation measurements can be properly …
The “k” Indices
The seasonal and diurnal variations of solar irradiance are described by well - established astronomical relationships. At the short-term, the behaviour of solar radiation is mainly ruled by the stochastic …
Optimal Radiometry and Correction Techniques
Previous sections have described the sources of errors that affect solar radiation measurements. During the last decade, the results from high-quality research in ra - diometry have considerably improved our …
Conditioned Distributions kt
We have also analysed the PDFs and the CDFs of the kt conditioned by the kt hourly average value represented, respectively, by f(kt|kH) and F(kt|kH) expressions. In order to obtain …
Discussion of the Two Methods
According to the analysis of Dubuc et al. (Dubuc et al. 1989), the Box-counting dimension and the Minkowski-Bouligand dimension are mathematically equivalent in limit thus, Db = Dm. However, they …
Frequency Distribution and Distribution Types for Clear Day Irradiation Index
The frequency distribution type for each monthly Kc database was determined based upon their respective skewness and kurtosis values. It was observed that January, February, March and December are classified …
Solar Radiation Measurement Fundamentals
Solar radiation consists of electromagnetic radiation emitted by the Sun in spectral regions ranging from X-rays to radio waves. Terrestrial applications of renewable energy utilizing solar radiation generally rely on …
Density and Cumulative Distribution Functions
In mathematical sense a histogram is simply a mapping mi that counts the number of observations (frequencies) that fall into various disjoint categories (known as bins or intervals). The histograms …
Measurement Networks and Data Quality Assessment
Finding measured solar radiation data involves locating measurement networks and experimental stations. Most countries have established and maintained national networks, but the number and quality of these networks is constantly …
Conclusions and Future Work
We would like to relate some of the main results of this work and to discuss the future research in the field of the modelling of the statistical properties of …
Measuring the Fractal Dimension of Signals
4.1 A Survey of Existing Methods Many natural processes described by time series (e. g., noises, economical and demographic data, electric signals... etc.) are also fractals in the sense that …
Frequency Distribution and Distribution Types for Clear Day Horizontal Beam Irradiation Index
The frequency distribution of the clear day horizontal beam irradiation index for the database consisting of all 12 months is shown in Fig. 4.9. Since the data are normalized, viz., …
Components of Solar Radiation in the Atmosphere
From the Earth, the solar disk subtends a solid angle of about 0.5° on average. Due to the eccentricity of the Earth’s elliptical orbit (0.0167), the distance from the Earth …
A Research Survey on the Statistical Behaviour of Solar Radiation Components
We will shortly review here the most important studies on the statistical solar radiation behaviour, with special focus on those works that have produced important advances on solar radiation modelisation. …
Large Networks and Primary Data Sources
Member countries of WMO contribute measured data to the World Radiation Data Center (WRDC), located at the Main Geophysical Observatory in St. Petersburg, Russia. The WRDC serves as a central …
