rayleighRayleigh Criterion refers to imagingoptical system Medium,Discriminative abilityIt measures the ability to separate the images of two adjacent objects.Due to diffraction, the image formed by the system is no longer an ideal geometric point image, but has a certain sizefacula（Aili spot）When two object points are too close and their image spots overlap, it may be impossible to distinguish the image of two object points, that is, there is aResolution limitThis resolution limit usually adopts the criterion proposed by Rayleigh: when the center of one Airy spot is at the first level with another Airy spotDark ringWhen they coincide, they can just distinguish two images.
Spectral lineMany, easy to overlap, and only two adjacent spectral lines are considered to be separated when they are clear enough.Rayleigh criterion shows that under ideal conditions:Spectral line intensityequal;Imaging systemnothingaberration, there is no halo near the spectral line;slitWhen the width is infinite, when the diffraction main line of one spectral line happens to fall on the first dark line of another spectral line, it can be considered that these two spectral lines have just been distinguished.[1]
Calculation formula
Announce
edit
Rayleigh criterion:
(radians)[2]
Where,
Is the resolution,
Is the wavelength,
Is the aperture of the optical system.
In the visible light range, take
=550 nm,
In centimeters,
In angular seconds, the calculation formula is
(Angular seconds)[2]
For example, the resolution of the human eye is 14/0.6=23 ", while the resolution of the 2.16m telescope is 14/216=0". 06. According to this data, the distance that the human eye can distinguish the details at a distance of 10cm is 0.9 km, and the ability of the 2.16m telescope is to extend this distance to more than 300 km.
