A periscope is a device with which you can observe objects outside our field of vision. Complex and precise instruments are made for complex and accurate observations. In these cases, the periscopes are equipped with a very complex optical system. However, for amateur purposes, you can construct a simple periscope from two pocket mirrors. It will allow you to penetrate the secrets of the life of shy birds and other animals.
The proposed design has an important additional advantage: the periscope can be significantly lengthened if the object of interest is hidden behind a high obstacle. The necessary materials are sold in stationery and dry goods stores. You will need two sheets of flexible cardboard and two pocket mirrors. The shape of the mirrors does not matter - they can be either round or rectangular. - but always the same.
In accordance with the size of the mirrors, glue two tubes about 50 cm long out of cardboard or paper, and one of them should be slightly larger in diameter so that the tubes fit into each other. (If you have rectangular mirrors, then, of course, the "holders" in the cut can be square).
When the glue dries, cut one hole with a sharp knife in the side walls of the tubes, at their ends. Moreover, the hole through which you will look into the periscope, make a diameter of about G cm. And the hole in the second tube should correspond in size to the mirror inserted outside.
Cutting a hole in a square tube is very easy, but if the cross section is round, it is more difficult. It is very important to keep in mind that the center of the holes must coincide with the center of the mirrors. Glue the sun protection devices to the holes, it is much more convenient to conduct observations with them.
From pieces of cardboard or foam, make two stands with holders to position the mirrors in the tubes.
After the glue that connects the stands, holders and mirrors has dried, the finished units of our periscope are inserted into one another. Again, it is necessary to precisely adjust their position in relation to the holes cut in the side walls of the tubes. The mirrors should be at an angle of 45 ° to the longitudinal axis of the device and direct the observed image as shown in the figure.
Before the final installation of the periscope, you need to perform one more operation - painting. The inner surfaces of the periscope are painted black, for example, with drawing ink. This improves observation conditions. Paint the outside of the periscope with gray or gray-green water-repellent paint. These colors are maximum, they blend well with the surrounding objects.
ROMAN KOZAK
The magazine "Horizons of technology for children" №8-85.
PERISCOPE, an optical device that makes it possible to examine objects located in horizontal planes that do not coincide with the horizontal plane of the observer's eye. It is used on submarines for observing the sea surface when the boat is submerged, in the land army - for safe and invisible observation of the enemy from protected points, in technology - for examining inaccessible internal parts of products. In its simplest form, the periscope consists of a vertical tube (Fig. 1) with two mirrors S 1 and S 2 tilted at an angle of 45 ° or prisms with total internal reflection, located parallel to each other at different ends of the tube and facing each other with their reflective surfaces ... However, the periscope reflective system can be designed in different ways. The system of two parallel mirrors (Fig. 2a) gives a direct image, the right and left sides of which are identical with the corresponding sides of the observed object.
A system of two perpendicular mirrors (Fig. 2b) gives the opposite image, and since it is viewed by an observer with his back to the object, the right and left sides change their places. Image flipping and side displacement can be easily achieved by placing a refractive prism in the system, but the need to observe with the back to the object, and therefore the difficulty in orientation, remains, and therefore the second system is less suitable. The disadvantages of the periscope shown in FIG. 1 and used in trench warfare, are an insignificant angle of view α (about 10-12 °) and a small aperture ratio, which forces one to be limited to a length of no more than 1000 mm with a relatively large pipe diameter - up to 330 mm. Therefore, in a periscope, a reflective system is usually associated with a lens system. This is achieved by attaching a telescope to the reflective system of the periscope, one or two. At the same time, since an ordinary astronomical tube gives a reverse image with displaced sides, the combination of perpendicular mirrors with such a tube will give a direct image with correctly located sides. The disadvantage of this system is the position of the observer with his back to the object, as mentioned above.
Attaching an astronomical tube to a system of parallel mirrors is also impractical, since the image will turn out upside down, with turned sides. Therefore, a periscope usually combines a system of parallel mirrors and a terrestrial telescope, which gives a direct image. However, the installation of two astronomical tubes after two inversions will also give a direct image, which is why it is also used in the periscope. In this case, the pipes are placed with lenses facing each other. The refractive system of the periscope does not present any peculiarities in comparison with the telescope, however, the choice of one or another combination of telescopes (more precisely lenses), their number and focal length is determined by the required angle of view and aperture of the periscope. In the best periscopes, image brightness is reduced by ≈30% depending on the system and lens type.
Since the clarity of the image also depends on the color of objects, the improvement of visibility is also achieved by using color filters. In the simplest form of a periscope (Fig. 3), the upper lens O 1 gives at point B 1 a real image of the object, refracting the rays reflected by the prism P 1. The collecting lens U creates at point B2 also a real image of the object, which is reflected by the prism P2 and viewed through the eyepiece O 2 with the eye of the observer. Achromatic lenses are commonly used in pipes, and measures are taken to eliminate other aberration distortions. By installing one after the other two telescopes, acting like the one described above, it is possible to increase the distance between the prisms without affecting the periscope's luminosity and its field of view. The simplest periscope of this type is shown in FIG. 4. Already the first periscopes of this type gave a field of view of 45 ° and an increase of 1.6 with an optical length of 5 m with a tube diameter of 150 mm.
Because observation with one eye is tiresome, then periscopes were proposed that give an image on frosted glass, but this image significantly lost its clarity, and therefore the use of frosted glasses in periscopes did not gain popularity.
The next stage in the development of the idea of \u200b\u200bperiscopes was attempts to eliminate the need to rotate the periscope tube when viewing the horizon at 360 °. This was achieved by connecting several (up to 8) periscopes on one tube; in each of the eyepieces, the corresponding part of the horizon was examined, and the observer had to go around the tube. Multiplier periscopes of this kind did not give the whole picture as a whole, and therefore omniscopes were proposed that give the entire horizon in the form of a ring pattern due to the replacement of the objective with a spherical refractive surface. Instruments of this kind, differing in considerable complexity, did not give an increase in the vertical field of view, which prevented the observation of aircraft, and distorted the image, and therefore fell out of use. More successful was the strengthening of the optical system in the inner tube, which could rotate inside the outer tube independently of the latter (Fig. 5).
Panoramic periscopes of this kind, or kleptoscopes, require some additional optical device. The light beam, penetrating into the periscope head through a spherical glass cover H, which protects the device from water ingress and does not play an optical role, propagates through the optical system P 1, B 1, B 2, etc., which is fixed in the inner tube J. The latter rotates with the help of a cylindrical gear train, shown at the bottom of the device with handle G, regardless of the outer casing M. In this case, the image falling on the lens B 3, refracted by the prism P2 and viewed by the eyepiece, will rotate about the light axis of the eyepiece. To avoid this, a quadrangular prism D is fixed inside the inner tube, rotating about the vertical axis by means of planetary gear K 1, K 2, K 3 at half speed and straightening the image.
The optical essence of the device is clear from FIG. 6, which shows how rotating the prism rotates the image at twice the speed. An increase in the field of view in the vertical direction from 30 ° in a conventional periscope to 90 ° is achieved in the zenith periscope by installing a prism in the objective part of the device, rotating about the horizontal axis, regardless of the rotation of the entire upper part about the vertical axis to view the horizon. The optical part of this type of periscope is shown in FIG. 7.
Periscopes are used on submarines for two purposes: observation and control of torpedo fire. Observation can consist of simple orientation in the environment and a closer examination of individual objects. Objects for observation d. B. visible in full size. At the same time, it has been practically established that for accurate reproduction with monocular observation of objects that are usually observed with the naked eye binocularly, an increase in the device should be used. more than 1.
Currently, all submarine periscopes have a magnification of 1.35-1.50 for easy orientation. For a close examination of individual items, increase db. more, with the highest possible illumination. At present, an increase of X 6 is used. periscopes have a double requirement for magnification. This requirement is satisfied in bifocal periscopes, the optical part of the objective of which is given in Fig. 8.
The change in magnification is achieved by rotating the system through 180 °, while the O 1 lens and the K 1 lens do not move. For a higher magnification, the V '1, P "2, V' 2 system is used, for a smaller one - the V 1, P 1, V 2 system. The appearance of the lower part of the zenith bifocal periscope is given in Fig. 9.
The described construction for changing the magnification is not the only one. More simply, the same goal is achieved by removing unnecessary lenses from the optical axis of the device, fixed in a frame that can be rotated at will about the axis. The latter is constructed vertically or horizontally. For direction finding objects, determining their distance, course, speed and for controlling torpedo firing, periscopes are equipped with special devices. FIG. 10 and 11 show the bottom of the periscope and the observed field of view for a periscope equipped with a vertical reference rangefinder.
FIG. 12 shows the field of view of the periscope for determining distance and heading according to the alignment principle.
FIG. 13 shows the lower part of a periscope equipped with a photographic camera, and FIG. 14 - the lower part of the periscope with a device for controlling torpedo fire.
The periscope head, when moving, causes waveforms on the sea surface, which make it possible to establish the presence of a submarine. To reduce visibility, the head of the periscope is made as small as possible, which reduces the aperture of the periscope and requires overcoming significant optical difficulties. Usually, only the upper part of the pipe is arranged narrow, gradually expanding it downward. The best modern periscopes, with a tube length of more than 10 m and a diameter of 180 mm, have an upper part about 1 m long with a diameter of only 45 mm. However, it has now been established by experience that the discovery of a submarine is achieved not by the detection of the periscope head itself, but by the visibility of its trace on the sea surface, which persists for a long time. Therefore, at present, the periscope is protruded above the sea surface periodically for a few seconds necessary for the observation, and now it is hidden until it appears again after a certain period of time. The wave formation caused in this case is much closer to the usual waves of sea water.
The difference in temperature in the pipe and in the environment in conjunction with the humidity of the air inside the periscope leads to fogging of the optical system, to eliminate which devices are arranged for drying the periscope. An air tube is installed inside the periscope, led to the top of the tube and outward at the bottom of the periscope. On the other side of the latter, an opening is made from which air is sucked out of the periscope and enters a filter charged with calcium chloride (Fig. 15), after which it is pumped into the upper part of the periscope by an air pump through an inner pipe.
The periscope tubes must meet special requirements for strength and rigidity in order to avoid disruption of the optical system; in addition, their material should not affect the magnetic needle, which would disrupt the operation of the ship's compasses. In addition, pipes d. B. especially resistant to corrosion in seawater, since in addition to the destruction of the pipes themselves, the tightness of the connection in the gland through which the periscope extends from the hull of the boat will be violated. Finally, the geometric shape of the pipes must be particularly precise, which, given their large length, creates significant difficulties in production. A common material for pipes is low-magnetic stainless nickel steel (Germany) or special bronze - Imadium (England), which has sufficient elasticity and rigidity.
Reinforcement of the periscope in the hull of the submarine (Fig. 16) causes difficulties, depending both on the need to prevent the ingress of seawater between the periscope tube and the hull of the boat, and on the vibration of the latter, which disturbs the clarity of the image. The elimination of these difficulties lies in the design of an oil seal that is sufficiently waterproof and at the same time resilient, securely connected to the hull of the boat. The pipes themselves must have devices for quickly lifting and lowering them inside the hull of the boat, which, with a periscope weight of hundreds of kg, leads to mechanical difficulties and the need to install motors 1, which rotate winches 2, 4 (3 - turn on for middle position, 5 - manual drive , 6, 7 - handles for the clutch mechanism). When raising or lowering the tube, observation is made impossible as the eyepiece moves rapidly vertically. At the same time, the need for observation is especially great when the boat is surfacing. To eliminate this, a special platform for the observer is used, connected to the periscope and moving with it. However, this causes an overload of the periscope tubes and the need to allocate a special shaft in the ship's hull to move the observer. Therefore, a stationary periscope system is more often used, which allows the observer to maintain his position and not interrupt his work while the periscope is moving.
This system (Fig. 17) dismembers the ocular and objective parts of the periscope; the first remains stationary, and the second moves vertically with the pipe. To connect them optically, a four-sided prism is installed at the bottom of the pipe, etc. the light beam in the periscope of this design is reflected four times, changing its direction. Since the movement of the tube changes the distance between the lower prism and the eyepiece, the latter intercepts the light beam at its various points (depending on the position of the tube), which violates the optical unity of the system and leads to the need to include in it another movable lens that regulates the beam rays according to the position of the pipe.
Usually, at least two periscopes are installed on submarines. Initially, this was due to the desire to have a spare device. At present, when two periscopes of different designs are required - for observation and attack, the periscope used during the attack is at the same time a spare in case of damage to one of them, which is important for performing the main task - observation. Sometimes, in addition to the indicated periscopes, a third one is also installed, a spare one, used exclusively for damage to both main ones.
Army periscopes are characterized by greater simplicity of design compared to naval ones, while maintaining the main features and improvements of the device. Their design is different depending on the purpose. A typical trench periscope consists of a wooden tube with two mirrors (Fig. 1). The device of the periscope tube is more complicated, it includes an optical refractive system, but does not differ in special dimensions; such a tube is usually arranged on the principle of a panoramic periscope (Fig. 18).
The dugout periscope (Fig. 19) is similar in design to the simplest marine type and is intended for making observations from shelters.
The mast periscope is used to observe distant objects or in the forest, replacing inconvenient and cumbersome towers. It reaches a height of 9-26 m and consists of a mast that serves to reinforce the optical system, mounted inside two short large diameter pipes. The eyepiece tube is attached to the carriage at the bottom of the mast, and the objective tube is attached to the retractable top of the mast. Thus, in this type there are no intermediate lenses, which, despite a significant increase (up to x 10), at a low position of the mast causes the latter to decrease as the mast extends with a simultaneous decrease in image clarity. The mast is mounted on a special carriage, which also serves to transport the device, and the mast moves. The carriage is quite stable and requires additional fastening with branches only in strong winds. The periscope is successfully used in technology for examining holes drilled in long forgings (shafts, tool channels, etc.), to check the absence of cavities, cracks, and other defects. The device consists of a mirror located at an angle of 45 ° to the channel axis, fixed on a special frame and connected to the illuminator. The frame moves inside the channel on a special rod and can rotate about the channel axis. The telescopic part is mounted separately and is placed outside the test forging; it serves not to transmit the image, as in an ordinary periscope, but to better view the field of view captured by the periscope.
A periscope is an optical instrument. It is a telescope that has a system of mirrors, prisms and lenses. Its purpose is to carry out surveillance from a variety of shelters, which include shelters, armored towers, tanks, submarines.
Historical roots
The periscope dates back to the 1430s, when the inventor Johannes Gutenberg invented a device that allowed observing the spectacles at fairs in the city of Aachen (Germany) over the heads of the crowds.
The periscope and its structure were described by the scientist Jan Hevelius in his treatises in 1647. He intended to use it in the study and description of the lunar surface. He was also the first to suggest using them for military purposes.
The first periscopes
The first real and workable periscope was patented in 1845 by the American inventor Sarah Mather. She managed to seriously improve this device and bring it to practical use in the armed forces. So, during the Civil War in the United States, soldiers attached periscopes to their guns for covert and safe shooting for themselves.
The French inventor and scientist Davy adapted the periscope for the naval forces in 1854. His device consisted of two mirrors deployed at an angle of 45 degrees, which were placed in a tube. And the first periscope used on was invented by the American Doughty during the American Civil War in 1861-1865.
During World War I, combatants also used periscopes of various designs to fire from cover.
During the Second World War, these devices were widely used on the battlefields. In addition to submarines, they were used to observe the enemy from shelters and dugouts, as well as on tanks.
Almost since the appearance of submarines, periscopes on them have been used to carry out observation when the submarine is underwater. This happens at the so-called "periscope depth".
They are designed to clarify the navigation situation on the sea surface and to detect aircraft. When the submarine begins to submerge, the periscope tube is retracted into the sub's hull.
Design
The classic periscope is a construction of three separately located devices and parts:
- Optical tube.
- Lifting device.
- Drawer units with oil seals.
The most complex structural mechanism is the optical system. These are two astronomical tubes aligned with each other by lenses. They are equipped with mirror prisms of total internal reflection.
The submarines have additional devices for the periscope. These include rangefinder devices, systems for determining heading angles, photo and video cameras, light filters, and drying systems.
To establish the distance to the target in the periscope, two types of devices are used - ranging grids and micrometers.
A light filter is irreplaceable in the periscope. It is located in front of the eyepiece, divided into three sectors. Each sector is a glass of a certain color.
The camera of the apparatus or another, designed to obtain an image, is necessary to establish the facts of hitting targets and record events on the surface. These devices are installed behind the periscope eyepiece on special brackets.
The periscope tube is hollow and contains air, which contains a certain amount of water vapor. In order to remove moisture deposited on the lenses, which condenses on them due to temperature changes, a special drying device is used. This procedure is carried out by quickly passing dry air through the pipe. It absorbs accumulated moisture.
On a submarine, the periscope looks like a pipe protruding above the wheelhouse with a "knob" at the end.
Use tactics
To ensure stealth, the submarine's periscope is raised from under the water at regular intervals. These intervals depend on weather conditions, speed and range of objects of observation.
The periscope assists the submarine commander in determining the direction (bearing) from the submarine to the target. Allows you to determine the heading angle of the enemy vessel, its characteristics (type, speed, armament, etc.). Gives information about the moment of the torpedo salvo.
The dimensions of the periscope protruding from under the water, its head head, should be as small as possible. This is necessary to prevent the enemy from fixing the location of the submarine.
For submarines, enemy aircraft are very dangerous. As a result, during the crossings of submarines, considerable attention is paid to monitoring the air situation.
However, to carry out such a combined observation, the end part of the periscopes is quite massive, since it houses the anti-aircraft observation optics.
Therefore, two periscopes are installed on submarines, namely the commander (attack) and anti-aircraft. With the help of the latter, it is possible to monitor not only the air situation, but also the sea surface (from the zenith to the horizon).
After the periscope is raised, the air hemisphere is examined. Observation of the water surface is initially carried out in the bow sector, and then goes on to review the entire horizon.
To ensure stealth, including from enemy radar systems, in the intervals between the ascents of the periscope, the submarine maneuvers at a safe depth.
Typically, the elevation of the submarine's periscope above sea level is in the range from 1 to 1.5 meters. This corresponds to a horizon visibility at a distance of 21-25 cables (about 4.5 km).
The periscope, as mentioned above, should be above the sea surface for the shortest possible period of time. This is especially important for a submarine that starts an attack. Practice says that it takes a little time to determine the distance and other parameters, about 10 seconds. Such a time interval for the presence of the periscope on the surface ensures its complete secrecy, so it is impossible to detect it in such a short time.
Footprints on the surface of the sea
When the submarine moves, the periscope leaves behind a trail and a breaker. It can be clearly seen not only in calm weather, but also with a slight roughness of the sea. The length and nature of the breaker, the size of the track, are in direct proportion to the speed of the submarine.
So, at a speed of 5 knots (about 9 km / h), the length of the periscope trail is about 25 m. The foam trail from it is clearly visible. If the speed of the submarine is 8 knots (about 15 km / h), then the length of the track is already 40 m, and the breaker is visible at a great distance.
When the submarine moves in calm weather, a pronounced white breaker color and a volumetric foamy trace appear from the periscope. It remains on the surface even after the device is retracted into the housing.
As a result, before raising it, the submarine commander takes measures to slow down the movement speed. In order to reduce the visibility of the submarine, the tip is streamlined. This is easy to see on the available periscope photos.
Other disadvantages
The disadvantages of this surveillance device include the following:
- It cannot be used at night or in poor visibility conditions.
- A periscope looking out of the water can be detected without significant difficulty both visually and with the help of radar equipment of a potential enemy.
- Photos of such a periscope taken by observers are the hallmark of the submarine's presence here.
- With its help, it is impossible to determine the distance to the target with the required accuracy. This circumstance reduces the effectiveness of the use of torpedoes on it. Moreover, the detection range of the periscope leaves much to be desired.
All of the above shortcomings have led to the fact that, in addition to periscopes, new, advanced surveillance tools for submarines have appeared. This is primarily a radar and hydroacoustics system.
The periscope is a must-have instrument on a submarine. The introduction of new devices (radar and hydroacoustic) into the technical systems of modern submarines did not diminish its role. They only supplemented its capabilities, making the submarine more "sighted" in poor visibility, in conditions of snow, rain, fog, etc.
- ▲ optical device for (what), improvement, ability, vision optical devices expand vision capabilities. ▼ a mirror allows you to see the other side of the field of view, for example, your face. polarizer. glasses optical device for correction ... ... Ideographic Dictionary of the Russian Language
An optical device that allows you to observe the sea horizon and the air from a submarine going under water at a certain shallow depth (about 5 m). Samoilov K.I. Marine dictionary. M. L .: State Naval Publishing House of the Union NKVMF ... ... Marine Dictionary
PERISCOPE, an optical device consisting of a series of MIRRORS or PRISM, designed to observe the surroundings from a shelter. The principle of operation is based on changing the direction of the observer's line of sight. Since World War II, the periscope is usually ... ... Scientific and technical encyclopedic dictionary
PERISCOPE - an optical device consisting of a visual (see) and a system of mirrors or prisms and serving to observe from a shelter over ground, air space or the sea surface, when direct observation is impossible, for example. from trenches, dugouts, ... ... Big Polytechnic Encyclopedia
This article is being proposed for deletion. You can find an explanation of the reasons and the corresponding discussion on the Wikipedia page: To be deleted / August 2, 2012. While the discussion process is not completed, you can try to improve the article, but you should ... ... Wikipedia
- (Greek, from peri, and skopeo I explore). A device in submarines for viewing the environment. Dictionary of foreign words included in the Russian language. Chudinov AN, 1910. periscope (gr. Periskopeo I look around, examine) an optical device with ... ... Dictionary of foreign words of the Russian language
periscope - a, m. périscope m. gr. periscopeo look. An optical device for observing objects located outside the immediate field of view of the observer. BAS 1. Lieutenant Kalyuzhny stood in front of a matte board, into which the periscope reflected ... ... Historical Dictionary of Russian Gallicisms
- (from peri ... and ... scope) 1) an optical device for observation from shelters (trenches, dugouts, etc.), tanks, submarines, etc. Using a periscope, horizontal and vertical angles are measured on the ground and distances are determined before the observed ... ... Big Encyclopedic Dictionary
PERISCOPE, periscope, man (from the Greek. periskopeo I look around) (special). Optical instrument, bent telescope for observing from the closures, from a submarine. Ushakov's explanatory dictionary. D.N. Ushakov. 1935 1940 ... Ushakov's Explanatory Dictionary
PERISCOPE, ah, husband. An optical device for observation from shelters (from a dugout, from a submarine, from an armored tower). Artillery, tank, trench, ship p. | adj. periscope, oh, oh. Ozhegov's Explanatory Dictionary. S.I. Ozhegov, N.Yu. Shvedova ... Ozhegov's Explanatory Dictionary