How does antifrogman sonar work?

This is no different from the ordinary active sonar principle, which is also a process of emitting, receiving, and processing sound wave signals.

It's just that frogmen belong to small targets, and the required frequency band for sonar is high, a few hundred hertz, to increase resolution. Of course, the transducer base element is also very small, the base array is much smaller than other sonars, the transmission power is not too high, and the high-frequency attenuation is very fast, and the action distance is very short, about dozens of meters.

Sonar works on the principle that it is a tool that uses sound for reconnaissance.

1. Sonar is composed of transmitters, transducers, receivers, displays, timers, controllers and other main components. The transmitter creates an electrical signal, passes through a transducer (usually a piezoelectric crystal), and transmits the electrical signal into an acoustic signal and sends it into water.

2. When the acoustic signal is transmitted in the water, if it encounters a target such as a submarine, a mine, or a school of fish, it will be reflected back, and the reflected sound wave will be received by the transducer and turned into an electrical signal, which will be amplified and displayed on the fluorescent screen or turned into sound in the headphones. The distance to the target can be determined based on the signal round-trip time, and the nature of the target can be judged based on the pitch of the voice.

3. The target is a submarine, which is a steel shell, and the echo is not only clear, but also has a long echo; The echoes of the school of fish are low and chaotic. If the target is moving, then the pitch of the echo should change due to the "Doppler effect": the pitch keeps getting higher, indicating that the target is moving closer to them; The pitch keeps getting lower, indicating that the target is far away from us.

According to the time, phase, intensity and other information of the received signal, the azimuth, distance, volume and other information of the reflector are analyzed.

Underwater sound waves are used for detection, localization, and communication.

It's a high-frequency transducer. It can emit sound waves of a certain frequency in a directional manner, and the sound waves travel out, and when they encounter obstacles, they will reflect back, and sonar will record the time of the sound waves to and fro. Then, according to the speed of the sound wave in the medium, the distance from the obstacle to the sonar can be calculated.

Emitting sound waves, they will reflect back when they encounter obstacles, and Geng measures the distance from the sonar to the obstacles.

The electronic equipment that uses underwater sound waves to detect, locate and communicate underwater targets is the most widely used and important device in hydroacoustics.

Same with radar! But he's in the water.

Use underwater sound waves to detect and locate underwater targets.

Sonar is an electronic device that uses sound waves in water to detect, locate, and communicate. Acoustics (sonar) is the main technology used by navies to conduct underwater surveillance, which is used to detect, classify, locate and track underwater targets; Carry out underwater communication and navigation, ensure the tactical maneuvering of ships, anti-submarine aircraft and anti-submarine *** and the use of underwater ***. In addition, sonar technology is widely used in torpedo guidance, mine fuzes, fish detection, offshore oil exploration, ship navigation, underwater operations, hydrographic surveys, and seabed geological and geomorphological surveys.

Sonar can be divided into various types of sonar according to the way it works, according to the object of equipment, according to the tactical use, according to the carrying mode of the base array, and according to the technical characteristics. For example, according to the way of work, it can be divided into active sonar and passive sonar; According to the equipment object, it can be divided into surface ship sonar, submarine sonar, aviation sonar, portable sonar and coastal sonar, and so on.

The sonar system is basically composed of a signal generated by it, amplified by it, a modulator controls the sonar or sonar array, and the sound wave will reflect back when it encounters an object, and then it is received by the hydrophone, and the signal amplification processing is recorded and analyzed. See ** for the rationale.

。Sonar works on the principle of echo sounding (similar to radar). Sonar is divided into passive sonar (or agitated sonar) and active sonar according to the way it works, and today's sonar has both.

Take passive sonar as an example: when a target in water or on the surface of the water moves, mechanical vibration and noise will be generated, and transmitted to the sonar transducer through the seawater medium, and the transducer converts the sound wave into an electrical signal and transmits it to the receiver, which is amplified and transmitted to the display console for display and audiometry orientation. Passive sonar has good concealment and strong ability to identify targets, but it cannot reconnoiter stationary targets.

Active sonar solves this problem, but active sonar is easy to expose itself and has a short detection range.

Sonar detectors work by emitting sound waves and receiving the reflected acoustic signals. The electromagnetic waves that radar relies on are heavily attenuated underwater and simply not enough for long-range detection. The sound wave is generated by the vibration of the object, and the propagation distance in the water is very far, and a huge ** in the water can be heard thousands of kilometers away.

The sonar device is generally composed of three parts: the base array, the electronic cabinet and the auxiliary equipment. The base array is composed of a certain geometric arrangement and combination of underwater acoustic transducers, and its shape is usually spherical, cylindrical, flat or line row, and it is divided into receiving base array, transmitter array or transmitting and receiving integrated base array. Electronic cabinets generally have subsystems such as transmitting, receiving, displaying, and controlling.

Auxiliary equipment includes power supply equipment, connecting cables, underwater junction boxes and amplifiers, lifting, rotating, pitching, retracting, dragging, hoisting, putting and other devices that are matched with the transmission control of the sonar base array, as well as sonar shrouds.

Transducer is an important device in sonar, which is a device that converts sound energy with other forms of energy such as mechanical energy, electrical energy, magnetic energy, etc.

There are two categories, active sonar and passive sonar.

Sonar is the main technology used by navies of various countries for underwater surveillance, which is used to detect, classify, locate and track underwater targets; Carry out underwater communication and navigation, ensure the tactical maneuvering of ships, anti-submarine aircraft and anti-submarine *** and the use of underwater ***. In addition, sonar technology is widely used in torpedo guidance, mine fuzes, fish detection, offshore oil exploration, ship navigation, underwater operations, hydrographic surveys, and seabed geological and geomorphological surveys.

As with the development of many science and technology, the needs of society and the progress of science and technology have promoted the development of sonar technology. The Russian Navy specially converted a nuclear K-403 submarine into a sonar test boat, which shows the importance it attaches to it.

When it comes to observation and measurement in water, only sound waves are the only ones that have unique conditions. This is due to the fact that the range of action of other detection means is very short, and the penetration ability of light in the water is very limited, even in the clearest seawater, people can only see objects within ten meters to tens of meters;

Electromagnetic waves also decay too quickly in water, and the shorter the wavelength, the greater the loss, even if high-power low-frequency electromagnetic waves are used, they can only propagate a few tens of meters. However, the attenuation of sound waves propagating in the water is much smaller, in the deep-sea channel, a bomb of a few kilograms, 20,000 kilometers away can also receive a signal, low-frequency sound waves can also penetrate the seabed thousands of meters of the formation, and get the information in the formation. No more effective means of measuring and observing in water than sound waves has been found.