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Derivation of the optical invariant, a measure of the light propagating through an optical system. The document ITU-R pp. 676–78 of the ITU-R section considers the atmosphere as being divided into spherical homogeneous layers; each layer has a constant refraction index. By the use of trigonometry, a couple of formulas and an algorithm were ...
Meteorological optics is "that part of atmospheric optics concerned with the study of patterns observable with the naked eye". [2] Nevertheless, the two terms are sometimes used interchangeably. Meteorological optical phenomena, as described in this article, are concerned with how the optical properties of Earth's atmosphere cause a wide range ...
When atmospheric refraction is considered, ray tracing becomes necessary (Kivalov 2007), and the absolute air mass integral becomes [7] = where is the index of refraction of air at the observer's elevation above sea level, is the index of refraction at elevation above sea level, = +, = + is the distance from the center of the Earth to a ...
Diagram showing displacement of the Sun's image at sunrise and sunset Comparison of inferior and superior mirages due to differing air refractive indices, n. Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. [1]
In 1998, NASA astrophysicist Yu Wang from the Jet Propulsion Laboratory for the first time proposed to use the Earth as an atmospheric lens. [2] Wang suggests in his paper that: [3] ''If we could build a space telescope using the Earth's atmosphere as an objective lens the aperture of such space telescope would be the diameter of the earth.
Image distance in a spherical mirror + = () Subscripts 1 and 2 refer to initial and final optical media respectively. These ratios are sometimes also used, following simply from other definitions of refractive index, wave phase velocity, and the luminal speed equation:
An electromagnetic wave propagating along a path C has the phase shift over C as if it was propagating a path in a vacuum, length of which, is equal to the optical path length of C. Thus, if a wave is traveling through several different media, then the optical path length of each medium can be added to find the total optical path length. The ...
Spectral optical depth or spectral optical thickness is the natural logarithm of the ratio of incident to transmitted spectral radiant power through a material. [1] Optical depth is dimensionless , and in particular is not a length, though it is a monotonically increasing function of optical path length , and approaches zero as the path length ...