periscope

(redirected from periscopic)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to periscopic: periscopic sextant, periscopic lens

periscope

(pĕr`ĭskōp) [Gr.,=view around], instrument to enable a person to see objects not in his direct line of vision or concealed by some intervening body. Its essential parts are a tube, prisms, lenses, mirrors, and an eyepiece. The image is received in one mirror and reflected through the tube with its lenses to a mirror visible to the viewer. Periscopes used in submarines are so arranged that they can be turned to permit a view of the entire horizon, with built-in rangefinders and typically six times magnification. Submarine periscopes are of noncorrosive metal, have tubes up to 30 ft (9.1 m) long and about 6 in. (15 cm) in diameter (only a small section projects above the water), and may be withdrawn into the submarine. Many smaller types of periscopes are used in trenches and tanks. With the development of fiber optics, periscopes (known as cystoscopes or endoscopes) have become useful in medicine.

Periscope

 

an optical instrument for viewing from such military shelters as trenches and dugouts, from tanks, and from submarines. Many periscopes permit measurement of horizontal and vertical angles on the terrain and also range-finding. The design and optical characteristics of a periscope are determined by its purpose, place of installation, and the depth from which observations are to be made.

The simplest periscope is the vertical type, consisting of a vertical sighting tube and two mirrors. Set at 45° angles to the axis of the tube, the mirrors form an optical system that refracts light rays coming from the observed object and directs them toward the observer’s eye. Periscopes in which right-angle prisms are installed in the tube instead of mirrors are common, as are telescopic lens systems and rotating systems, which can be used to obtain an erect magnified image. The field of vision of a periscope with low magnification (up to 1.5 power) is about 40°; it usually decreases with greater magnification. Certain types of periscopes give panoramic vision.

periscope

[′per·ə‚skōp]
(optics)
An optical instrument used to provide a raised line of vision where it may not be practical or possible, as in entrenchments, tanks, or submarines; the raised line of vision is obtained by the use of mirrors or prisms within the structure of the item; it may have single or dual optical systems.
A thin astigmatic lens which approximates a meniscus shape and has a base curve of ±1.25 diopters.
References in periodicals archive ?
The commander is equipped with a periscopic sight provided with either a two-FoV direct view optic sight or a three-FoV CCD for day aiming and surveillance, and a three-FoV thermal imager.
(17) Sebald mentions another important reason for the choice of periscopic narration in his interview with Der Spiegel.
The one on the top with square-shaped chamber is said to be the periscopic camera with a 10x lens.
A combined periscopic gunner's sight with a dependent LOS (movement in the vertical plane together with the weapon) and a non-stabilized electric drive were used to fire the main weapon and coupled machine gun of the first-generation BMP-1 IFV.
Tailing off into a blue-broom "tail fin," extending upward into periscopic tin-can "oculars," and opening out into a wing of honeycombed steel, its metallic chassis seems to be a transformed workbench centered by two disks or "gears," one of blue Plexiglas, another of mosaicked mirror, the whole seeming to refer to the studio in which it was made.
As part of the navigation team, I did all of the celestial observations for the navigator using the periscopic sextant.
The Pro variant is said to be a camera-centric device and the latest leak has suggested that it will sport a periscopic camera just like we have seen in the recently-launched Huawei P30 Pro.
However, incorporating the lenses would have caused increased device thickness, which the company circumvented by employing a periscopic module that is placed horizontally.