According to the current technical level, the submarine integrated imaging system is basically composed of several types of imaging systems. The technical status and characteristics of several imaging systems are described in the order of airborne and non-airborne imaging systems.
Periscope imaging system
The modern submarine periscope was invented in the early 20th century. When the German Navy built its first submarine in 1906, 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 power of 5 ~ 7 meters, a short observation distance, a narrow field of view and poor imaging quality, so it could not be used at night. The main functions of the traditional periscope include observing ships on the water, observing planes 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 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 SERO 400 periscope newly developed in Germany in 2003 as an example. The main technical performance includes: pitching range-15 ~ 60,10.5 times, 6 times, 12 times, high-precision sight line is biaxial stable, periscope entrance pupil diameter is greater than 2 1mm, and periscope force is about 12m. 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, laser rangefinders for human eye safety, etc. , for submarine commanders to choose according to actual needs; The video signal can also be provided to the monitor of the combat system in real time to realize synchronous observation. The serial interface of periscope system can be used for remote control of consoles of different combat systems. Periscope system has good observation effect in both day and night 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 and played back.
Modern photoelectric periscope technology is quite mature, and it is impossible to improve it greatly. The inherent shortcomings of the traditional penetrating periscope are very obvious: first of all, this is also the main defect. The periscope must penetrate the submarine shell, and the larger the diameter of the lens barrel, the greater the influence on the submarine pressure resistance; Secondly, the rotating diameter of periscope lens is generally 0.6 meters, which occupies a large space in the originally limited boat, which is very unfavorable to the layout of submarine command module; Thirdly, 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 combat information resources. Although there are some defects in progress, photoelectric periscope is still the most commonly used imaging observation equipment for naval submarines in various countries at present and in the future.
Photoelectric mast system
1976, kollmorgen company formally put forward the original photoelectric mast principle for naval inspection. Then in the 1980s, the development plan of the 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. This 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 photoelectric mast observation head, non-penetrating mast and in-ship console. The photoelectric mast system on the Virginia class submarine in the United States is an /BVS? 1 imaging system, in addition to the functions of the existing periscope system, 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 complex technology and high price, only a few submarines have used photoelectric masts at present. For example, Russia's "Delta Ⅲ" and "Delta Ⅳ" class missile nuclear submarines are equipped with "Brick Rain" photoelectric masts. Only the American "Virginia" class attack nuclear submarine used two photoelectric masts. At present, a photoelectric mast and a periscope are commonly used, such as some snorkeling camera monitoring systems in the United States, Britain, Germany, France, Russia, Japan, Egypt and other countries.
Camera TV system of shell part
This is a special application of TV camera system in submarine. It is mainly used to check and monitor the external environment and various launching conditions of submarines, and can also provide optical navigation for submarine activities under ice. Television camera system has been used in submarine hull for at least 30 years, especially in British, Russian and Nordic naval submarines. The underwater television camera system installed on the British submarine shell 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 floating. Generally speaking, as far as the navigation system is concerned, two underwater TV cameras should be arranged on the submarine shell, one of which is placed in the upward observation position and the other is placed in the forward view position at an angle of 40 with the horizontal direction. This arrangement is very beneficial for the submarine to obtain the best quality image when floating or maneuvering forward. OE of Simrad company in Britain? The 0285 camera has been equipped with a British submarine. It is an enhanced silicon target camera, which can observe various targets through weak light when the stars are cloudy. When does the submarine move in the Arctic Ocean, OE? 0285 camera is an important auxiliary equipment when submarine floats in ice.
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 shell. Virtual periscope is an optical sensor that can completely see the water surface 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 upper hemisphere field of view of the sea into a complete image. The integration of virtual periscope and submarine sensor system can reduce the number of times that 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 diving depth, it must be confirmed that there are no ships in the floating area. The "transition zone" from diving depth to about 150 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 sailboat above because it is "too deep", because the sailboat is "too shallow" to pass safely. 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 maneuverability 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 surface; Virtual periscope is to use one or several upward-looking cameras under water to receive light from space and penetrate the ocean. Virtual periscope project develops an underwater camera system (including software system) that can detect water targets by using the imaging technology of reconstructing weakly refracted light. Virtual periscope is not only a special imaging technology, but also fully suitable for the application of submarine special operations forces.
Photoelectric buoy system
The United States applied for the patent of photoelectric buoy technology as early as the early 1980s. In 1990s, the ship imaging system company in pocahontas, Massachusetts, USA started the design and research of photoelectric buoys for submarines. The company signed a research contract worth 654.38 million US dollars with the Defense Research Projects Agency to design and manufacture a camera buoy system (BCD) launched from submarines. BCD adopts CCD sensor, which is connected with submarine through optical fiber and cable. The stability and monitoring direction of CCD sensor are controlled by submarine, and the target image data is obtained on the water surface, and then converted into optical fiber signals and transmitted to submarine. The obtained information is processed by image enhancement algorithm software. The photoelectric buoy for submarine can be invisible to improve its concealment, such as disguised as ice or floating objects at sea. If the cost can be reduced, the photoelectric buoy can be designed to be disposable. It is also suggested to develop a multi-sensor photoelectric buoy system.
Uav system
The development of submarine unmanned aerial vehicle (UAV) has solved the problem that periscope and photoelectric mast periscope are low in height and cannot be observed from a distance. The submarine can get the images taken by the unmanned aerial vehicle when it is submerged, thus improving the concealment. The research on submarine-related UAV technology began in the mid-1980s. At that time, the drone was launched from the torpedo tube, and now it can be launched from the submarine mast. For example, the UAV launcher developed by kollmorgen Company in the United States is installed in the submarine mast, which can hold four UAVs at a time. The US Navy has applied UAV technology to Virginia-class and Ohio-class attack nuclear submarines. UAV can transmit the detected information to the launching submarine through military satellites, or forward it to other submarines, surface ships and operational command centers on land, and form an integrated information network with various systems such as underwater vehicles.