An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 5 Search : skin
masking
  ماسک‌زد   
mâskzad

Fr.: masque, masquage   

1) A method of improving → spatial resolution of images. → pupil masking; → unsharp masking.
2) Computers: The process of specifying a number of values that allow extracting desired information from a set of characters or bits while suppressing the undesired information.

Verbal noun of → mask.

pupil masking
  ماسک‌زد ِ مردمک   
mâskzad-e mardomak

Fr.: masquage de pupille   

A method for reaching the → diffraction-limited  → angular resolution of a monolithic telescope by using an → interferometric technique. A mask with several small openings is placed in the telescope pupil plane or in a conjugated plane so as to only pass light from selected regions, thus transforming the telescope into an array of small subapertures without redundancy. When the light from each of these separate subapertures is combined, → interference fringes are formed which encode information on the spatial structure of the source (Haniff et al. 1987, Nature 328, 694). Coupled with a novel technique which filters the → atmospheric turbulence through fibers, pupil masking allows reaching a high dynamic range (Perrin et al. 2006, MNRAS 373, 747), which is necessary for detecting very faint objects, such as → exoplanets, adjacent to bright stars.

pupil; → masking.

skin
  پوست   
pust (#)

Fr.: peau   

1) The external protective membrane or covering of an animal's body, or that surrounding the flesh of a fruit or vegetable.
2) The outer protective covering of a structure. → skin effect.

M.E., from O.N. skinn "animal hide;" cf. O.H.G. scinten, Ger. schinden "to flay, skin;" Ger. dialect schind "skin of a fruit," Flemish schinde "bark;" from PIE *sken- "to cut off."

Pust "skin;" Mid.Pers. pôst "skin;" O.Pers. pavastā- "thin clay envelope used to protect unbaked clay tablets;" Av. pastô-, in pastô.fraθanhəm "of the breadth of the skin;" Skt. pavásta- "cover," Proto-Indo-Iranian *pauastā- "cloth."

skin effect
  اُسکر ِ پوستی   
oskar-e pusti

Fr.: effet de peau   

The tendency of an → alternating current to concentrate in the outer layer of a conductor, caused by the → self-induction of the → conductor and resulting in increased → resistance.

skin; → effect.

unsharp masking
  ماسک‌زد ِ ناتیگ   
mâskzad-e nâtig

Fr.: masque floue   

A process for amplifying fine details in a registered image. Generally speaking, the process consists of creating a mask which contains larger scale features of the image and then subtracting the mask from the initial image.

un-; → sharp; → masking.