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  2. Angular resolution - Wikipedia

    en.wikipedia.org/wiki/Angular_resolution

    The Rayleigh criterion shows that the minimum angular spread that can be ... Using a small-angle approximation, the angular resolution may be converted into a ...

  3. Optical resolution - Wikipedia

    en.wikipedia.org/wiki/Optical_resolution

    Optical resolution describes the ability ... is the half angle of the pencil of ... The resolution predicted by this formula is proportional to the Rayleigh-based ...

  4. Rayleigh length - Wikipedia

    en.wikipedia.org/wiki/Rayleigh_length

    Gaussian beam width () as a function of the axial distance .: beam waist; : confocal parameter; : Rayleigh length; : total angular spread In optics and especially laser science, the Rayleigh length or Rayleigh range, , is the distance along the propagation direction of a beam from the waist to the place where the area of the cross section is doubled. [1]

  5. Airy disk - Wikipedia

    en.wikipedia.org/wiki/Airy_disk

    The Rayleigh criterion for barely resolving two objects that are point sources of light, such as stars seen through a telescope, is that the center of the Airy disk for the first object occurs at the first minimum of the Airy disk of the second. This means that the angular resolution of a diffraction-limited system is given by the same formulae.

  6. Sparrow's resolution limit - Wikipedia

    en.wikipedia.org/wiki/Sparrow's_resolution_limit

    Sparrow's resolution limit is nearly equivalent to the theoretical diffraction limit of resolution, the wavelength of light divided by the aperture diameter, and about 20% smaller than the Rayleigh limit. For example, in a 200 mm (eight-inch) telescope, Rayleigh's resolution limit is 0.69 arc seconds, Sparrow's resolution limit is 0.54 arc seconds.

  7. Rayleigh distance - Wikipedia

    en.wikipedia.org/wiki/Rayleigh_distance

    Rayleigh distance in optics is the axial distance from a radiating aperture to a point at which the path difference between the axial ray and an edge ray is λ / 4. An approximation of the Rayleigh Distance is Z = D 2 2 λ {\displaystyle Z={\frac {D^{2}}{2\lambda }}} , in which Z is the Rayleigh distance, D is the aperture of radiation, λ the ...

  8. Rayleigh sky model - Wikipedia

    en.wikipedia.org/wiki/Rayleigh_sky_model

    The scattering angle (the angle at the zenith between the solar direction and the observer direction) along the horizon is a circle. From the East through the West it is 180° and from the West through the East it is 90° at twilight. When the sun is setting in the West, the angle is then 180° East through West, and only 90° West through East.

  9. Rayleigh (unit) - Wikipedia

    en.wikipedia.org/wiki/Rayleigh_(unit)

    The rayleigh is a unit of photon flux, used to measure faint light emitted in the sky, such as airglow and auroras. It was first proposed in 1956 by Donald M. Hunten, Franklin E. Roach, and Joseph W. Chamberlain. [1] It is named for Robert Strutt, 4th Baron Rayleigh (1875–1947). [2] Its symbol is R (also used for the röntgen, an unrelated unit).