RU2733085C1 - Method of communication of underwater vehicle with aircraft - Google Patents

Abstract

FIELD: underwater sound and audio communication.

SUBSTANCE: invention relates to underwater sound and audio communication and can be used in hydroacoustic systems for organization of one-way communication immersed in water environment of object with air object. Method of communication of underwater vehicle with aircraft is characterized by that radiating path is located on underwater vehicle and consists of control computer, a pulse generator, a power amplifier, a radiating hydroacoustic antenna, and the receiving path is located on the aircraft and consists of a receiving acoustic antenna, a preamplifier, a band-pass filter, an exciter, a power amplifier emitting radio antennae, wherein the depth of submersion of the underwater vehicle (or its hydroacoustic antenna) shall not exceed the wavelength of the acoustic signal emitted by the hydroacoustic antenna; frequency of acoustic signal should lie in low-frequency (less than 1 kHz) or infrasound range; hydroacoustic antenna must have either a spherical or cylindrical emitting surface; dimensions of underwater vehicle shall not exceed the wavelength of emitted acoustic signal.

EFFECT: broader functional capabilities of communication systems installed on underwater and aircraft, high technical reliability and security of transmitting and receiving information for unilateral communication of underwater vehicles with aircraft.

1 cl, 1 dwg

Description

The invention relates to underwater and sound communication and can be used in hydroacoustic systems for organizing one-way communication of an object submerged in a water environment with an air object.

At present [1] the main methods of transmitting information from an underwater vehicle to an aircraft are associated with the direct ascent of the underwater vehicle to use radio antennas of ultra-short-wave or short-wave ranges [2], or the use of a sonar buoy [3], which can be dropped from the aircraft [ 4] or released from an underwater vehicle [5].

To begin with, let's consider the features associated with the emergence of an underwater vehicle to the surface to establish radio communication. Firstly, if an underwater vehicle floats to the surface, then by doing so it unmasks its location, and can be easily detected both by radars and satellites, and visually, which may be undesirable for a number of reasons. Secondly, ascent to the surface of an underwater vehicle may be difficult or even impossible due to the loss of buoyancy due to an accident or any other abnormal situation. Thirdly, it is worth taking into account drifting hydroacoustic stations and buoys, as well as stationary underwater platforms installed on the bottom, the surfacing of which may not be provided at all [6].

It is also possible to highlight a number of disadvantages typical of the use of sonar buoys in order to transfer information from an underwater vehicle to an aircraft. The first and main disadvantage is the one-time use of the sonar buoy. Together with the very short operating time of the sonar buoy and its high cost [7], this method of information transmission is extremely expensive. The second drawback is the limitations associated with the roughness of the sea and the speed of movement of the underwater vehicle. The third drawback is the overall dimensions of the hydroacoustic buoy [4, 5]. If the installation of a group of sonar buoys on large submarines has long been worked out without difficulty, then in the case of small autonomous unmanned underwater vehicles or underwater sonar stations and platforms, the expediency of using a group of sonar buoys is questionable.

The known method of two-way communication with an underwater object [8], designed to organize the exchange of information immersed in the aquatic environment of an object with underwater, surface, ground and air objects. In this method, the body of the underwater object is used as an active vibrator for communication. A shunt bridge is installed between the bow and stern points of the underwater object. The shunt bridge serves as a winding of the matching transformer. In the area of the stern and bow points, transformers are installed. These transformers are connected to the bypass link. One of the transformers is connected to the input of the radio receiver, and the other is connected to the input of the radio transmitter. In this case, the bow and stern points of the underwater object are used as the most distant points.

The disadvantage of the analogue is the dependence of the method on the length of the shunt bridge and the geometrical dimensions of the underwater object, which ensure the maximum separation distance of the end points of its conducting body, which is used as an active electric vibrator of the receiving and transmitting antennas. This solution is focused on underwater objects with a large displacement and will not provide long communication ranges on small autonomous unmanned underwater vehicles, marine robotic systems and bathyscaphes.

Also known is a method of two-way long-distance radio communication with an underwater object [9], designed to organize two-way communication and navigation without surfacing an object immersed in the aquatic environment, for example, a submarine, with underwater, surface, ground, air objects and spacecraft, including covering the water surface with ice. The technical result consists in improving the method of two-way long-distance radio communication of an underwater object with underwater, surface, ground, air and space objects, reducing the power of radiated radio waves, increasing the information content and secrecy of radio communication. For this, in the method of two-way long-distance radio communication with an underwater object of underwater, surface, ground, air objects and spacecraft, including when the water and earth surfaces are covered with ice, radio waves with an extremely low power density of 10 μW / cm are used to receive and transmit information radio signals. ² and below at the resonant frequencies of the radio transparency of the aquatic environment in the extremely high-frequency (EHF) and ultra-high-frequency (UHF) ranges. At the same time, generators of tunable and resonant fixed carrier frequencies of EHF and UHF ranges and highly sensitive radio receivers at a fixed UHF or EHF resonant frequency are used, transmitting and receiving coordinated contact and remote directional low-noise antennas and antenna systems, means of encoding, decoding and data processing located in places reception and transmission of radio signals at the carrier resonant frequencies of the aquatic environment.

The disadvantage of the analogue is the dependence of the method on the properties of the aqueous medium in which the underwater object is located. The chemical composition of the aquatic environment can vary over a wide range of values, depending on the area and depth. Thus, the resonant frequency of the radio transparency of the aquatic environment will change.

The closest in technical essence to the claimed invention is a method for transmitting information from an underwater object to an aircraft [10], intended for use in radar and hydroacoustic systems when organizing combined communication channels in sea conditions. The achieved technical result is an increase in the time of a communication session between a moving underwater object and an aircraft. This result is achieved due to the fact that the frequency of the electromagnetic waves is changed synchronously with the change in the angle of incidence according to a certain law.

The disadvantage of the prototype is the need to coordinate different types of media at the interface. For the aquatic environment, the carrier of information is hydroacoustic waves, while for the air, the carrier of information is electromagnetic waves.

The objective of the invention is to develop a method for transmitting information from an underwater vehicle to an aircraft by means of acoustic waves.

The technical result of the invention is to expand the functionality of communication systems installed on underwater and aircraft, improve the technical reliability and secrecy of transmission and reception of information for one-way communication of underwater vehicles with aircraft.

Theoretical and experimental studies show [11, 12] that, under certain conditions, the effect of anomalous transparency of the water-air interface for acoustic waves is observed. The essence of the effect lies in a significant increase in the pressure transmission coefficient of acoustic waves from water to air. The value of the transmission coefficient depends on the wave distance between the hydroacoustic antenna and the interface between the media. The reason for the effect is explained by the properties of an inhomogeneous plane wave. The amplitude of an inhomogeneous plane wave amplitude rapidly decreases in the direction of propagation. Therefore, an inhomogeneous plane wave exists only in the near field of the hydroacoustic antenna, and its contribution to the far field of the hydroacoustic antenna is insignificant. At the same time, the contribution of an inhomogeneous plane wave to the near acoustic field is much greater than the contribution of a homogeneous plane wave. Therefore, to implement the method of communication between an underwater vehicle and an aircraft, a number of conditions must be met:

- the immersion depth of the underwater vehicle (or its hydroacoustic antenna) should not exceed the wavelength emitted by the hydroacoustic antenna of the acoustic signal. For example, at a signal frequency of 500 Hz, the immersion depth of the underwater vehicle (or its sonar antenna) should not exceed 3 m;

- the frequency of the acoustic signal should be in the low-frequency (less than 1 kHz) or infrasonic ranges. At higher frequencies, the underwater vehicle will be forced to approach close to the interface, which is not always possible during strong sea waves;

- the sonar antenna must have either a spherical or cylindrical radiating surface. Since an acoustic wave with a spherical (or cylindrical) wavefront is the sum of homogeneous and inhomogeneous plane waves. As a result, the level of acoustic pressure in the air will simultaneously depend on two types of plane waves. An inhomogeneous plane wave is absent in an acoustic wave with a plane wavefront;

- the dimensions of the underwater vehicle should not exceed the wavelength of the emitted acoustic signal. Otherwise, multiple reflections of the acoustic signal may occur between the interface between the media and the body of the underwater vehicle.

The essence of the invention is presented in figure 1, where:

1 - information input device;

2 - control computer;

3 - pulse generator;

4 - power amplifier;

5 - emitting hydroacoustic antenna;

6 - receiving acoustic antenna;

7 - preamplifier;

8 - band pass filter;

9 - pathogen;

10 - power amplifier;

11 - emitting radio antenna.

The proposed method is implemented as follows.

The emitting path of the communication system is located on the underwater vehicle (Fig. 1, blocks 1-5). Any hydroacoustic apparatus, both manned and non-manned, can act as an underwater vehicle. Using the input device 1, the operator enters the transmitted message and the parameters of its transmission into the control computer 2, which converts the message and the parameters of its transmission into control electrical signals. Further, the control electrical signals from the output of the control computer 2 are fed to the input of the pulse generator 3, which, under the influence of the control electrical signals, generates electrical radio pulses of a given duration, amplitude and frequency. If the underwater carrier is uninhabited, then the input device 1 is absent, and the control computer 2 generates control electrical signals according to the program algorithm embedded in it. From the output of the pulse generator 3, electrical signals are fed to the input of the power amplifier 4, which converts a low-power electrical signal at the input into a higher-power signal at the output with minimal distortion of the shape. From the output of the power amplifier 4, the electrical signal is fed to the input of the emitting hydroacoustic antenna 5, which converts the electrical signal into a hydroacoustic signal, and then radiates it into the aquatic environment. The acoustic axis of the emitting piezoceramic hydroacoustic antenna 5 should be oriented towards the water surface.

The receiving path of the communication system is located on the aircraft (Fig. 1, blocks 6-10). Low-noise unmanned aerial vehicles must be used as an aircraft. This is justified by the fact that the level of their acoustic noise is much lower and the cost is less than that of manned jet or rotorcraft. The acoustic antenna 6 receives acoustic signals transmitted from water to air and converts them into electrical signals. It is recommended to use highly sensitive electro-acoustic transducers of the electrostatic type as an acoustic antenna 6. From the output of the acoustic antenna 6, the electrical signal enters the input of the preamplifier 7, which matches the impedances and raises the signal level to a practically acceptable value. Further, from the output of the preamplifier 7, the electrical signal is fed to the input of the band-pass filter 8, which makes it possible to isolate the spectrum components of the useful electrical signal and suppress unwanted ones, thereby improving the signal-to-noise ratio. From the output of the bandpass filter 8, the electrical signal is fed to the input of the exciter 9, which combines the functions of the master oscillator of the carrier wave frequency and the modulating device that changes the parameters of the emitted wave in accordance with the signal to be transmitted. From the output of the exciter 9, the electrical signal is fed to the input of the power amplifier 10, which increases the power of the electrical signal of the exciter to the required level. From the output of the power amplifier 10, the electrical signal is fed to the input of the emitting radio antenna 11, which converts the energy of the electromagnetic vibration into an electromagnetic wave propagating in space.

The industrial applicability of the invention is determined by the fact that the proposed method can be implemented according to the above description and drawing using well-known and widespread components.

Literature

1. Malashenko A.E., Mironenko M.V. and others. Creation and operation of radio-hydroacoustic systems for monitoring the hydrophysical fields of sea areas. - Vladivostok: SKB SAMI FEB RAS, 2012 .-- 263 p.

2. Sutyagin I. Means of communication of nuclear submarines of the Los Angeles type // Foreign military review. - 1995. - No. 9. - S. 52-57.

3. The device is a hydroacoustic jet buoy. Patent 2400392 RU from 25.05.2009, B63B22 / 00, B63G6 / 00.

4. Polmar N. The Naval Institute Guide to the Ships and Aircraft of the U.S. Fleet. 17th. - Annapolis: Naval Institute Press, - 2001, 592 p.

5. Friedman N. The Naval Institute guide to world naval weapons systems, 1997-1998. - Annapolis: Naval Institute Press, 1997 .-- 808 p.

6. Buoy station for hydrophysical measurements. Patent 2090431 RU from 28.02.1995, B63B22 / 06.

7. Artemiev A. Submarine hunters // Aviation and cosmonautics. - 1996. - T. 18. No. 7. - S. 3-11.

8. Method of two-way communication with an underwater object. Patent 2361364 RU from 18.06.2007, H04B 7/26, H04B 13/02.

9. Method of two-way long-distance radio communication with an underwater object. Patent 2666904 RU from 06.06.2017, H04B 13/02.

10. Method of transferring information from an underwater object to an aircraft. Patent 2710026 RU from 10.12.2018, G01S 13/78.

11. Voloshchenko A.P., Tarasov S.P. Effect of anomalous transparency of the liquid-gas interface for sound waves // Acoustic journal. 2013. T. 59. No. 2. P 186-192.

12. Voloshchenko A.P., Tarasov S.P. Experimental study of the transmission of low-frequency acoustic waves through a water – air interface // J. Acoust. Soc. Am. 2019. - V. 145. No. 1. - P. 143-148.

Claims (2)

1. A method of communication between an underwater vehicle and an aircraft, characterized in that the emitting path is located on the underwater vehicle and consists of a control computer, a pulse generator, a power amplifier, a radiating hydroacoustic antenna, and the receiving path is located on the aircraft and consists of a receiving acoustic antenna, a preamplifier, bandpass filter, exciter, power amplifier, radiating radio antenna, and the immersion depth of the underwater vehicle (or its hydroacoustic antenna) should not exceed the wavelength of the acoustic signal emitted by the hydroacoustic antenna; the frequency of the acoustic signal should be in the low-frequency (less than 1 kHz) or infrasonic ranges; the sonar antenna must have either a spherical or cylindrical radiating surface; the dimensions of the underwater vehicle should not exceed the wavelength of the emitted acoustic signal. 2. The method according to claim 1, characterized in that the emitting path comprises an information input device.

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