Periscope refers to a device that protrudes from the sea surface or the ground from a low-lying tunnel to spy on the activities on the sea surface or the ground. Its structure is the same as that of an ordinary telescope on the ground, except that two additional mirrors are added to make the object light be reflected twice and turned to the eyes. Periscope is often used in submarines, tunnels and tanks to observe the enemy.
Function
The only way for submarines in underwater navigation to observe sea level and air conditions is to use periscope. Most submarines are equipped with two periscopes ―― an attack periscope and an observation periscope. The former is used to find and aim at water targets, while the latter is mainly used to observe sea and air conditions and navigation observation. Before the submarine surfaced, the captain must command the submarine to make a 36-degree observation of the sea level with the periscope at the depth, in order to find the possible enemy situation as soon as possible. Submarines will only surface if there is no threat.
defects
the main component of the periscope is a long steel mast, which can rise to a height of 5 meters outside the command tower. Prisms and lenses are installed at both ends, which can enlarge the field of view of the periscope to 1X to 6X. There are two obvious problems in the use of periscope. The main problem is vibration. When the periscope is completely raised, the slender periscope mast will affect the normal navigation of the submarine and cause lateral instability. When the submarine's speed exceeds 6 knots, the periscope mast will bring great vibration, which will make it completely unusable. Later, additional mast supports were installed on the submarine, and the shape of the top of the periscope was redesigned and improved to reduce water wave resistance. Although the vibration has not been completely eliminated, it has been greatly improved. Another important problem is the fog produced by periscope lenses. Because the air inside the submarine is humid, the lens of the periscope will produce fog, so the periscope must be waterproof and sealed as much as possible when it is designed and manufactured. When a submarine is attacked by a deep bomb, it is easy to damage the sealing structure of the periscope, which leads to fog.
The observation periscope has a seat and pedal that can move with the lifting rod of the periscope. It is mainly used for sea and air observation and course confirmation before the submarine floats. The attack periscope is not available, and it is mainly used for enemy observation, target ranging and attack azimuth angle calculation. At the same time, the observation telescope is better at night observation.
Emerging technologies
However, AN/APS-116 anti-submarine search radar is specially designed to detect periscope-like targets with short exposure time in high sea conditions, so up periscope means exposing targets.
Edit this paragraph
Make a periscope
Preparation
To make a periscope, you only need two square mirrors and a piece of cardboard. If your small mirror is 1 cm long and 7 cm wide, you should prepare a Zhang Kuan 4×7=28 cm cardboard. The length of cardboard can be determined by itself according to the conditions. If the cardboard is longer, the periscope can be made higher.
manufacturing process
draw three parallel lines on the cardboard, and the distance between each line is seven centimeters as shown in the picture. Cut off the blackened part. Draw a mark along the dotted line with a knife (be careful not to cut through). Then, use the edge of the table to fold it, so as to make a rectangular box and stick it with kraft paper.
When using white tape to make a small mirror look like getting off the boat and sailing underwater, you must also use periscope to observe the sea surface.
Mystery of Invention
Who invented periscope? Now it is impossible to find out. The earliest ancient book in the world that recorded the principle of periscope was Huainan Wanbi Shu in China in the second century BC. The book records such a passage: "Take a big mirror and hang it high, put a water tray under it, and you will see your neighbors."
Similar inventions in history
In ancient times, under the eaves of some ancient temples in deep mountains in China, a bronze mirror was often hung obliquely. If you put a basin of water on the ground inside the temple gate, it will be the simplest periscope, and the narrow path and passers-by outside the temple gate will be reflected in the water.
1. Let's talk about making an inverted periscope. How to say the word "Kuang" in the overall shape of the inverted periscope? Remove the word "Wang" inside. That's it. Put two mirrors at 45 degrees at the upper and lower corners. You can draw a sketch, assuming that when a light enters the upper part of the mirror at the upper corner, its reflected light will be reflected at the lower part of the mirror below, thus standing upside down.
2. The upright periscope is shaped like a "Z", which makes the line connecting the upper part and the lower part vertical. Or, the shape is an "I" shape, and the right half of the upper horizontal line is removed. The left half of the lower horizontal line is removed. This image is upright.
The included angle between the two mirrors of the inverted periscope is 9 degrees, while the two mirrors of the upright periscope are parallel to each other.
Edit this paragraph
How to make it
Buy two small mirrors. Make two right-angle elbow cylinders with cardboard, the diameter of which is slightly larger than that of the small mirror. Open a 45 oblique opening at the two right angles of the paper tube, insert two small mirrors into the oblique opening relatively (as shown in Figure 1.1-3), stick them together with paper strips, and sleeve the two right-angle cylinders together to form a simple periscope.
hold the bottom tube still and turn the top tube, from which you can see the distant scenery.
Edit this paragraph
The working principle of periscope
According to the current technical level, the submarine integrated imaging system basically consists of eight categories of imaging systems. In the following, according to the order of on-board and off-board imaging systems, the technical status and characteristics of eight imaging systems are described respectively.
periscope imaging system
Modern submarine periscope was invented in the early 2th century. When the German Navy built its first submarine in 196, it had already used quite perfect optical periscope, which consisted of objective lens, image conversion system and eyepiece. At that time, the periscope had a periscope power of 5~7 meters, a close observation distance, a narrow field of view and poor image quality, and it could not be used at night. The main functions of traditional periscope include observing ships on the water surface, observing aircraft in the air, estimating the distance of the attacked target, providing its position and distance to the fire control system, and implementing landmark navigation or astronomical navigation in the submerged state.
Modern periscope manufacturers have developed a new generation of photoelectric periscope by applying the latest achievements of low-light-level night vision, infrared thermal imaging, laser ranging, computer, automatic control, stealth and other photoelectric technologies. Take the latest SERO 4 periscope developed by Germany in 23 as an example. The main technical performance includes: the pitch range is -15 degrees to+6 degrees, 1.5 times, 6 times and 12 times magnification, the high-precision aiming line is biaxial stable, and the periscope entrance pupil diameter >; 21 mm, periscope is about 12 meters. It can be equipped with a variety of cameras and sensors, such as digital cameras, low-light-level television cameras, color television cameras, thermal cameras, eye-safe laser rangefinders, etc., for submarine commanders to choose according to actual needs; It can also provide the video signal to the monitor of the combat system in real time to realize synchronous observation. The serial interface of periscope system can be used for different battle system consoles to realize remote control operation. The periscope system has a good observation effect in daytime and nighttime conditions, which can effectively monitor the sea surface and air, collect navigation data, search and identify various maritime targets, and the observed images can be recorded for playback.
The panoramic periscope recently developed by the US Navy is also worthy of attention. It is the re-application of early panoramic periscope technology under modern technical conditions, and the prospect of the technology is still being verified. In addition, foreign countries attach great importance to the modular design of periscope and have widely adopted it. Without changing the basic structure and function of periscope, the old sensor can be easily replaced as needed, and the performance of periscope can be improved.
the modern photoelectric periscope technology is quite mature, and it is impossible to improve it greatly. The inherent disadvantages of the traditional penetrating periscope are very obvious: the main defect is that the periscope must penetrate the submarine shell, and the larger the diameter of the mirror tube, the greater the influence on the submarine pressure resistance; Secondly, the rotating diameter of the periscope lens is generally .6 meters, which occupies too much space in the originally limited boat, which is very unfavorable to the layout of the submarine command module. Thirdly, the periscope is only suitable for one person to operate and observe, and it is impossible for many people to observe at the same time, which is not conducive to the enjoyment of operational information resources. Although there are progressive defects, photoelectric periscope is still the most commonly used imaging observation device for naval submarines in various countries at present and in the future.
photoelectric mast system
In p>1976, kollmorgen Company formally put forward the original principle of photoelectric mast for naval review. In 198s, the development plan of non-penetrating photoelectric mast was officially launched. Nowadays, photoelectric mast has developed from concept and principle prototype to engineering model. The navies of the United States, Britain and France have eliminated the traditional penetrating periscope on new nuclear-powered submarines, and they will all be equipped with photoelectric masts. The selection indicates that the submarine photoelectric mast technology has reached a quite mature and reliable level. The biggest difference between photoelectric mast and conventional periscope is that photoelectric mast is a "non-penetrating mast". It consists of three parts: photoelectric mast observation head, non-penetrating mast and in-boat control console. AN/BVS-1 imaging system is the photoelectric mast system on the Virginia class submarine in the United States. Besides the functions of the existing periscope system, it can also provide functions such as electronic intelligence collection, surveillance and target attack.
Compared with the traditional penetrating periscope, the photoelectric mast has many advantages: for example, the photoelectric mast does not penetrate the pressure hull, but is directly arranged in the appropriate position of the command module, which not only improves the pressure strength of the submarine, but also facilitates the layout of the command module; The observation head of the photoelectric mast is equipped with various photoelectric detection sensors, electronic warfare and communication antennas. The situation outside the boat can be photographed by TV and infrared camera, then transmitted to the boat and displayed on the monitor and big screen of the console. Photoelectric mast is gradually replacing penetrating periscope and becoming an important part of submarine combat information system.
However, due to the complicated technology and high price, only a few submarines have used a photoelectric mast at present. For example, Russian "Delta Ⅲ" and "Delta Ⅳ" missile nuclear submarines are equipped with a "Brick Rain" photoelectric mast. Only the American "Virginia" class attack nuclear submarine used two photoelectric masts. Although the British "Smart" and French "Victory" attack nuclear submarines are also equipped with two photoelectric masts, they have not yet been launched and it will take time to serve. At present, a photoelectric mast and a periscope are commonly used together. For example, some submarine snorkel camera monitoring systems in the United States, Britain, Germany, France, Russia, Japan, Egypt and other countries were invented by Germany during World War II. In the 196s, we began to study how to use the periscope observation device under the condition of the snorkel, so that the snorkel can be used for multiple purposes. At that time, the first choice was to install periscope on the snorkel, for example, the NavS periscope of Zeiss company in Germany could be installed on the snorkel of submarine. In recent years, more attention has been paid to the installation of observation and communication devices on submarine snorkel. In the American patent "snorkel device of submarine" applied by IKL company in Germany in September 24, how to configure periscope, radar and communication antenna on snorkel is described in detail, mainly involving electronic imaging technology and radar early warning technology. The snorkel camera monitoring system applies the submarine photoelectric mast technology to the snorkel device, so that the submarine can keep alert observation, communication and radar early warning while working in the snorkel state, which improves the concealment of the submarine. From a technical point of view, if you have mastered the photoelectric mast technology, it will not be very difficult to realize it on the snorkel. This technology has attracted the attention of people in the submarine industry.
Camera TV system in enclosure and shell
This is a special application of TV camera system in submarine. It is mainly used to inspect and monitor the external environment and various launching conditions of the submarine, and can also provide optical navigation for submarine activities under the ice. The application of TV camera system in submarine hull has a history of at least 3 years, and the specific application is more common in British, Russian and Nordic naval submarines. The underwater television camera system installed on the British submarine enclosure is specially developed for the needs of submarine activities on ice or underwater. It can provide safe underwater navigation and is an important auxiliary device for submarine to float. Generally speaking, as far as navigation systems are concerned. Two underwater TV cameras should be arranged on the submarine enclosure, one of which is placed in the upward observation position and the other in the forward view position at an angle of 4 degrees with the horizontal direction. This arrangement is very beneficial for the submarine to get the best quality image when it is floating or maneuvering forward. The OE-285 camera of British Unitary Mlad Company has been equipped with British submarines. It is an enhanced silicon target camera, which can observe various targets by weak light under the condition of cloudy starlight. OE-285 camera is an important auxiliary equipment when submarine moves in the Arctic Ocean.
Virtual periscope system
This is the submarine underwater camera system being studied by the US Navy. Although it is called a "virtual" periscope, it is completely different from the "virtual reality" in the field of computer technology and the camera system on the enclosure. Virtual periscope is a kind of optical sensor that looks through the water completely from the submarine platform, including submarine underwater camera, processor and image display. The so-called "virtual" means that the image display can reproduce the incomplete image in the hemispherical field of view of the upper part of the sea as a complete image. Virtual periscope is integrated with submarine sensor system, which can reduce the number of times submarine commanders use conventional periscope and improve submarine stealth.
Virtual periscope technology can also minimize the probability of collision between submarines and surface ships. Before the submarine floats to the submerged depth, it must be confirmed that there are no ships in the floating area. The "transition zone" from the diving depth to about 15 feet (46 meters) underwater is an unsafe area for submarine underwater activities. In this embarrassing area, the submarine can't see whether there is a sailing ship above because it is "too deep" and can't pass safely because it is "too shallow" below the sailing ship. However, this transition zone may contain the best underwater acoustic search depth and the best avoidance depth, and it is the most ideal depth area for submarines to operate safely in shallow water. If the submarine loses this transition zone, its mobility will be greatly reduced. If the submarine uses virtual periscope technology to observe the surrounding situation, it can move safely in this transition area.
the optical principle of virtual periscope is different from that of ordinary periscope. Ordinary periscope receives light at a certain position on the sea; Virtual periscope is to use one or several upward-looking cameras under water to receive light from space and penetrate the sea. The virtual periscope project uses the imaging technology of reconstructing weak refracted light to develop an underwater camera system (including software system) that can detect water targets. Virtual periscope is not only a special imaging technology, but also completely suitable for the application of submarine special operations forces. This technology is in the experimental stage.
Photoelectric Buoy System
As early as the early 198s, the United States applied for the patent of photoelectric buoy technology. In 199s, the ship imaging system company in Pocahontas, Massachusetts, USA started the design and research of photoelectric buoys for submarines.