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The first versions of SMARTS were developed by Dr. Gueymard while he was at the Florida Solar Energy Center. [2] [3] [4] The model employed a structure similar to the earlier SPCTRAL2 model, still offered by the National Renewable Energy Laboratory (), but with finer spectral resolution, as well as updated extraterrestrial spectrum and transmittance functions.
Mathematically, for the spectral power distribution of a radiant exitance or irradiance one may write: =where M(λ) is the spectral irradiance (or exitance) of the light (SI units: W/m 2 = kg·m −1 ·s −3); Φ is the radiant flux of the source (SI unit: watt, W); A is the area over which the radiant flux is integrated (SI unit: square meter, m 2); and λ is the wavelength (SI unit: meter, m).
cis-1,2-disub. alkenes 1660 medium trans-1,2-disub. alkenes 1675 medium trisub., tetrasub. alkenes 1670 weak conjugated C═C dienes 1600 strong 1650 strong with benzene ring 1625 strong with C═O 1600 strong C═C (both sp 2) any 1640–1680 medium aromatic C═C any 1450 weak to strong (usually 3 or 4) 1500 1580 1600 C≡C terminal alkynes
The SI unit of irradiance is the watt per square metre (symbol W⋅m −2 or W/m 2). The CGS unit erg per square centimetre per second (erg⋅cm −2 ⋅s −1) is often used in astronomy. Irradiance is often called intensity, but this term is avoided in radiometry where such usage leads to confusion with radiant intensity.
A solar simulator’s spectral match is computed by comparing its output spectrum to the integrated irradiance in several wavelength intervals. The reference percentage of total irradiance is shown below in Table 2 for the standard terrestrial spectra of AM1.5G and AM1.5D, and the extraterrestrial spectrum, AM0. Below is a plot of these two ...
The field of spectroradiometry concerns itself with the measurement of absolute radiometric quantities in narrow wavelength intervals. [1] It is useful to sample the spectrum with narrow bandwidth and wavelength increments because many sources have line structures [2] Most often in spectroradiometry, spectral irradiance is the desired measurement.
I (x, t ; r 1, ν) is defined to be such that a virtual source area, dA 1, containing the point P 1, is an apparent emitter of a small but finite amount of energy dE transported by radiation of frequencies (ν, ν + dν) in a small time duration dt, where = (,;,) (), and where θ 1 is the angle between the line of propagation r and the normal P 1 N 1 to dA 1; the effective destination of ...
The air mass coefficient can be used to help characterize the solar spectrum after solar radiation has traveled through the atmosphere. The air mass coefficient is commonly used to characterize the performance of solar cells under standardized conditions, and is often referred to using the syntax "AM" followed by a number.