RU2762349C1 - Method for covert hydroacoustic search for an autonomous bottom underwater object - Google Patents

Abstract

FIELD: surveillance.

SUBSTANCE: area of application: the invention relates to the field of underwater navigation and can be used in hydroacoustic monitoring systems for various purposes, integrated underwater surveillance systems, positional network-centric networks for covert hydroacoustic search for underwater objects located at the bottom of a known marine area from a surface search vessel in standby mode after completing the corresponding mission. Substance: the substantial differences of the claimed method are the use of adaptive coherent compensation for concentrated interference of interfering shipping traffic in partial reception paths of a direction-finding antenna, performed in pauses between the intervals of emission of a navigation signal from the underwater object, with frequency separation of interference from different surface sources in three selected sub-bands of frequencies and suspension of coherent compensation for the duration of reception of the navigation signal of the pinger beacon, when processing a navigation signal of the pinger beacon of an autonomous bottom underwater object on the search vessel, performing linear amplitude detection and post-detector addition of signals of partial reception paths of the direction-finding antenna after coherent compensation, which in combination allows for covert hydroacoustic search for an autonomous bottom underwater object in conditions of influence of concentrated interference of near and far shipping traffic.

EFFECT: provided covert hydroacoustic search for an autonomous bottom underwater object from a surface search vessel in conditions of influence of concentrated interference of near and far shipping traffic, implemented by modifying the structure of processing the navigation signal of the pinger beacon of an autonomous bottom underwater object on the search vessel.

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Description

The proposed invention relates to the field of underwater navigation and can be used in hydroacoustic monitoring systems for various purposes, integrated underwater surveillance systems, positional network-centric networks for covert hydroacoustic search from a surface search vessel for underwater objects located at the bottom of a known sea area in a dormant mode after completing the corresponding mission ...

There is a method of navigation [1], where the investigated polygon of the water area is coordinated by three acoustic transponder beacons, with which the autonomous underwater object interacts, receiving a request and transmitting its acoustic signal, and the beacons transmit their distances to the underwater object to the search vessel. The vessel calculates the coordinates of the object as the point of intersection of three spheres and refines them as the vessel approaches the underwater object.

This method is rather cumbersome, requires a lot of ship time for deployment, is expensive to operate, and does not ensure the secrecy of hydroacoustic search, since the signals of interaction of an autonomous underwater object, responder beacons and a search vessel are detected and identified by existing hydroacoustic observation and monitoring equipment, which is highly undesirable. circumstance when performing some reconnaissance and monitoring tasks in various sea areas.

Known hydroacoustic navigation system [2] with an ultrashort base for positioning underwater objects, in which the surface vessel is equipped with a four-element direction finding antenna of diametrically-orthogonal geometry, and the requested underwater object transmits to the surface vessel a combined signal, in general, consisting of navigation and information units. Appropriate processing of this signal makes it possible to determine with sufficient accuracy the parameters of the location of the underwater object: bearing, elevation, range, inclination distance relative to the surface vessel, and to receive the necessary information messages from the object. In this system, secrecy is also not provided, since the signals of interaction between the underwater object and the surface vessel are detected and identified by the existing hydroacoustic observation and monitoring means.

There is a method [3] for determining the location of an autonomous underwater vehicle equipped with a pinger beacon, emitting periodic tones, pre-synchronized with the ship's generator of similar reference signals, relative to the search vessel, the pinger beacon signals being received by the ship's antenna, calculating their time offset relative to of the same reference signals, multiplying which by the speed of sound in water, obtain the slant distance from the pinger beacon to the ship, using the ship's receiving antenna of the dipole type with a minimum radiation pattern and mechanically rotating it about the vertical axis, fix the bearing of the pinger beacon of the underwater vehicle relative to the ship coordinates by the minimum amplitude of the received signal, as well as using the ship's echo sounder, the depth of the water area under the ship is determined, then the range of the apparatus is calculated from the geometric construction, which, together with the bearing angle, gives an estimate of the approximate, relative the search vessel, the coordinates of the autonomous bottom underwater vehicle, which are constantly updated as the vessel moves in the direction of the positioned underwater vehicle.

This method also has a disadvantage associated with the lack of secrecy of the process of hydroacoustic search for an autonomous bottom underwater object, due to the use and possible identification of unmasking, artificially originated acoustic signals, which, according to hydroacoustic reconnaissance data, indicate the very fact of carrying out attention-grabbing underwater work.

The known method [4] of a covert hydroacoustic search from a surface search vessel of an autonomous bottom underwater object, which is a prototype method of the proposed method, which assumes, in the general process of hydroacoustic search, the following actions, procedures and operations.

1. The search vessel is equipped with a direction finding antenna of diametrically orthogonal geometry of the location of four receiving hydrophones, a weakly directional transmitting hydroacoustic antenna, equipment for receiving and processing the navigation signal of a pinger beacon of an autonomous bottom underwater object based on a highly stable reference generator, equipment for generating activation and ascent signals an autonomous bottom underwater object, a hydroacoustic echo sounder for measuring the depth of the search water area with the structure of sounding pulses, which makes it possible to provide acoustic perception of the procedure for measuring the depth of the water area of the search, approaching a possible hybrid noise background of the marine environment.

2. Equip an autonomous bottom underwater object with a buoyancy change system, weakly directional receiving and transmitting hydroacoustic antennas, equipment for receiving and processing signals for activation and surfacing of a search vessel, a pinger beacon that generates a repetitive navigation signal using a highly stable reference generator.

3. During the preparation of the mission of the autonomous underwater object on the underwater object and the search vessel, the signals emitted during the hydroacoustic search are formed and stored: on the autonomous underwater object - the navigation signal of the pinger beacon, on the search vessel - activation and ascent signals of the autonomous bottom underwater object having a given structure, amplitude, time and frequency parameters, by acoustic perception approaching the possible background noise of the known search water area, while the activation and surfacing signals of the search vessel consist of two components: the starting message and the identification message, and the navigation signal of the pinger beacon of the autonomous bottom underwater object contains four components: a starting message, an identification message, a navigation message in the form of a harmonic signal of the frequency known on the search vessel and a quasi-white noise masking the navigation message, the frequency parameters of which ensure the required accuracy in determining the angles x coordinates of the autonomous bottom underwater object relative to the search vessel in the process of its hydroacoustic search, in addition, the structure and parameters of the emitted navigation signal of the pinger beacon of the autonomous bottom underwater object are a priori known on the search vessel, and the structure and parameters of the emitted signals of activation and surfacing of the search vessel are known a priori at an autonomous bottom underwater facility.

4. Prior to the search, the procedure for calibrating the partial paths for receiving the navigation signal of the search vessel is performed, with the receipt and storage of the calibration corrections.

5. As the search vessel moves along the search water area, its transmitting antenna into the aquatic environment of the lower hemisphere space relative to the search vessel emits a repeating hydroacoustic activation signal of an autonomous bottom underwater object, exceeding the background noise of the water environment of the search water area.

6. Received by means of the receiving antenna and carry out the necessary processing on the autonomous bottom underwater object of the hydroacoustic activation signal of the search vessel.

7. The equipment of the autonomous bottom underwater object is transferred, upon the fact of reliable reception of the activation signal, from the sleeping mode to the operating mode.

8. The transmitting antenna of an autonomous bottom underwater object is emitted into the aquatic environment of the search area, in the directions of the upper hemisphere, relative to the seabed, a hydroacoustic navigation signal, which exceeds the background noise of the aquatic environment, generated by a pinger beacon and repeating with an interval longer than its duration.

9. The direction finding antenna of the search vessel receives the navigation signal of the pinger beacon and is subjected to appropriate processing, with the subsequent termination, in fact of its reliable reception, of radiation by the transmitting antenna of the search vessel of the sonar activation signal of the autonomous bottom underwater object.

10. Measure and store the depth of the water area of the search by the echo sounder of the search vessel.

11. During the search process, on the search vessel, the procedure for determining and storing the angular coordinates of the autonomous bottom underwater object relative to the search vessel is carried out, coordinated with the geometric parameters of the direction finding antenna and allowing the autonomous bottom underwater object to be positioned relative to the search vessel with the required accuracy in conditions of low signal / masking noise of the pinger beacon navigation message.

12. Approximate values of the range and slope distance to the autonomous bottom underwater object using the corresponding trigonometric ratios are estimated and memorized at a certain elevation angle and measured depth of the water area of the search.

13. The course of movement of the search vessel is corrected based on the updated parameters of the location of the autonomous bottom underwater object relative to the search vessel, as it moves through the search water area to a predetermined safe ascent range of the autonomous bottom underwater object.

14. The transmitting antenna of the search vessel is emitted into the aquatic environment of the search water area, in the space of the lower hemisphere, relative to the search vessel, in the pause between the emissions of the navigation signal of the pinger beacon of the autonomous bottom underwater object, the hydroacoustic signal of the ascent of the autonomous bottom underwater object exceeding the background noise of the aquatic environment.

15. Receive on the autonomous bottom underwater object by means of the receiving antenna, with the implementation of the necessary processing, the hydroacoustic signal of ascent.

16. On the fact of reliable reception of the ascent signal, the emission of the navigation signal of the pinger beacon by the transmitting antenna of the autonomous bottom underwater object is stopped.

17. The corresponding actuators of the system for changing the buoyancy of the autonomous bottom underwater object are launched.

18. If, after the first emission by the search vessel of the ascent signal, the reception of navigation signals of the pinger beacon of the autonomous bottom underwater object on the search vessel does not stop, then the re-emission of the ascent signal is carried out.

Fragments of sonograms of records of sounds of sea animals, fish, crustaceans and noises of the shallow or deep sea with specified amplitude, time and frequency parameters are used as the necessary components of the activation and surfacing signals of the search vessel, the navigation signal of the pinger beacon of the autonomous bottom underwater object. In this case, the fragments used have a pronounced impulse character with a well-distinguishable structure for reliable impulse reception, and fragments of sonograms of recordings of shallow or deep sea noise, selected depending on the depth of the known water area of the search for an autonomous underwater object and having statistical characteristics similar to quasi-white noise, serve as the basis for the formation of noise masking the harmonic navigation message of the pinger beacon of the autonomous bottom underwater object.

The frequency parameters of the quasi-white noise masking the navigation message of the pinger beacon of the autonomous underwater object are determined based on the required accuracy of estimating the angular coordinates of the autonomous bottom underwater object relative to the search vessel during its hydroacoustic search, ensuring that the lower boundary frequency of its spectrum exceeds the frequency of harmonic oscillations of the navigation transmissions at least five times, and the upper cutoff frequency of the quasi-white noise spectrum is matched with the upper border of the passband of the transmission path of the autonomous bottom underwater object.

During the hydroacoustic search of an autonomous bottom underwater object within the search water area, it is possible that various surface vessels may appear, passing by the search vessel at different distances and interfering with the reception of the navigation signal of the pinger beacon of the autonomous bottom underwater object on the search vessel, arising from the reflection of the noise hydroacoustic signals of the surface vessels. ships from the seabed.

FIG. 1 shows an example of the occurrence of two interferences from passing surface vessels during hydroacoustic search of an autonomous unmanned underwater vehicle, where the following are indicated: 1 - surface search vessel; 2 - autonomous unmanned underwater vehicle; 3 - direction finding antenna of the search vessel; 4 - muddy seabed; 5, 6 - passing surface vessels; 7 - rocky fragments of the seabed; ϕ, θ - bearing and elevation angle of the autonomous unmanned underwater vehicle in the coordinate system of the direction finding antenna of the search vessel; d is the range of an autonomous unmanned underwater vehicle; h is the immersion depth of an unmanned underwater vehicle; r _n - the slope distance from the search vessel to the unmanned underwater vehicle.

The presented example of a possible reflection from rock fragments of the seabed of interfering hydroacoustic signals of passing vessels corresponds to the appearance, when processing a pinger beacon signal of an autonomous unmanned underwater vehicle on a search vessel, two interference sources, the sources of which (places of reflection from rock fragments of the seabed) have elevation angles (in the coordinate system direction finding antenna of the search vessel) exceeding the elevation angle of the positioned autonomous unmanned underwater vehicle.

Warships and civilian ships plying in various waters of the world's oceans are very strong sources of interference in the process of the considered hydroacoustic search for autonomous underwater objects. The noises created by these objects can be conditionally divided into three groups: noises of machines and auxiliary mechanisms, noises associated with the operation of propellers, and hydrodynamic noises.

FIG. 2 shows the most typical noise spectra of various surface vessels taken from sources [5].

Noise interference from surface vessels, according to available statistics, can be classified as concentrated (narrow-band) interference with frequency spectra located in a relatively low-frequency (in terms of the range of propagation of acoustic vibrations) frequency range (from tens of hertz to one kilohertz), as a result of which the levels of such interference in places of possible reception of navigation signals when searching for underwater objects can exceed the level of fluctuation noise of the marine environment by 80-100 dB.

In a mathematical assessment of the effectiveness of suppression of concentrated interference in various radio engineering systems, the interference model is used in the form of a narrow-band random process with varying amplitude and phase of oscillations of a given average frequency of its energy spectrum [6].

Recommended in the prototype method [4], the time-frequency parameters of the navigation signal emitted by the pinger beacon of the autonomous bottom underwater object, shown in FIG. 3, allow us to draw two important system conclusions:

- a navigation signal with a total duration of no more than 2.22 seconds is emitted during the hydroacoustic search with a frequency of at least 8 seconds, that is, it has a large duty cycle with a time interval at which only interference can be present - fluctuation noise of the marine environment and concentrated interference of near and long distance navigation, but there is no navigation signal of the pinger beacon of the autonomous bottom underwater object;

- the frequency spectra of lumped interference for near and long-distance navigation are in the frequency range of the pinger beacon navigation signal identification message, which does not allow suppression of navigation interference by means of conventional frequency filtering and reliable reception of the pinger beacon navigation signal identification message on the search vessel with subsequent processing navigation message in the process of searching for an autonomous bottom underwater object.

The technical result of the proposed method is the implementation of a covert hydroacoustic search from a surface search vessel of an autonomous bottom underwater object under the influence of concentrated interference from near and long-distance navigation, implemented by modifying the structure of processing the navigation signal of the pinger beacon of an autonomous bottom underwater object on a search vessel.

This technical result is achieved due to the fact that in the method of covert hydroacoustic search from a surface search vessel of an autonomous bottom underwater object, which is in a dormant mode at the bottom of a known sea area after completing a corresponding mission, which consists in equipping the search vessel with a diametric direction finding antenna, which is coordinated with its course. orthogonal geometry of the arrangement of four receiving hydrophones, a weakly directional transmitting hydroacoustic antenna, equipment for receiving and processing the navigation signal of the pinger beacon of an autonomous bottom underwater object based on a highly stable reference generator, equipment for generating activation signals and ascent of an autonomous bottom underwater object, a sonar echo sounder for measuring the depth of the search water area structure of sounding pulses, allowing to provide acoustic perception of the procedure for measuring the depth of the water area of the search, approaching a possible hybrid noise background of the marine environment, in equipping an autonomous bottom underwater object with a buoyancy change system, weakly directional receiving and transmitting hydroacoustic antennas, equipment for receiving and processing signals for activation and surfacing of a search vessel, a pinger beacon that generates, using a highly stable reference generator, a repetitive navigation signal, in the formation and memorization during the preparation of the mission of an autonomous underwater object on an underwater object and a search vessel, the signals emitted during the hydroacoustic search process: on an autonomous underwater object - a navigation signal of a pinger beacon, on a search vessel - activation and ascent signals of an autonomous underwater bottom object having a given structure , amplitude, time and frequency parameters, according to the acoustic perception, approaching the possible background noise of the known search area, while the activation and surfacing signals of the search vessel consist of two components: signals and identification messages, and the navigation signal of the pinger-beacon of an autonomous underwater object contains four components: a starting message, an identification message, a navigation message in the form of a harmonic signal of the frequency known on the search vessel and a quasi-white noise masking the navigation message, the frequency parameters of which ensure the required determination accuracy angular coordinates of the autonomous bottom underwater object relative to the search vessel in the process of its hydroacoustic search, in addition, the structure and parameters of the emitted navigation signal of the pinger beacon of the autonomous bottom underwater object are a priori known on the search vessel, and the structure and parameters of the emitted signals of activation and surfacing of the search vessel are known a priori on an autonomous seabed underwater object, in the execution before the search of the procedure for the calibration of the partial paths for receiving the navigation signal of the search vessel with the receipt and storage of calibration corrections, in a repetitive , as the search vessel moves through the search water area, its transmitting antenna radiates into the aquatic environment of the lower hemisphere, relative to the search vessel, the hydroacoustic signal of activation of an autonomous bottom underwater object, exceeding the background noise of the water environment of the search water area, in reception by the receiving antenna and the necessary processing on an autonomous bottom underwater object of a hydroacoustic signal of activation of a search vessel, in translation of the equipment of an autonomous bottom underwater object, upon the fact of reliable reception of an activation signal, from a sleeping mode to an operating mode, in the radiation of a transmitting antenna of an autonomous bottom underwater object into the aquatic environment of the search water area, in the directions of the upper hemisphere, relative to the seabed, a hydroacoustic navigation signal exceeding the background noise of the aquatic environment, generated by a pinger beacon and repeated with an interval longer than its duration, in the reception of the direction finding antenna of a search vessel on the signal of the pinger beacon and its corresponding processing, with the subsequent termination, upon the fact of its reliable reception, of the emission by the transmitting antenna of the search vessel of the hydroacoustic signal of activation of the autonomous bottom underwater object, in measuring and storing the depth of the water area of the search by the echo sounder of the search vessel, in implementation, in the process search, on the search vessel, the procedure for determining and storing the angular coordinates of the autonomous underwater bottom object relative to the search vessel, coordinated with the geometrical parameters of the direction finding antenna and allowing positioning of the autonomous bottom underwater object relative to the search vessel with the required accuracy in conditions of low signal / masking noise ratio of the navigation signal of the beacon - pinger, in assessing and memorizing at a certain elevation angle and measured depth of the water area of the search for approximate values of the range and slope distance to the autonomous bottom underwater object using the appropriate trigonometric ratios, in correcting the course of movement of the search vessel based on the updated parameters of the location of the autonomous bottom underwater object relative to the search vessel, as it moves through the search water area to a predetermined safe surfacing range of the autonomous bottom underwater object, in the radiation of the transmitting antenna of the search vessel into the aquatic environment the search water area, in the space of the lower hemisphere, relative to the search vessel, in the pause between the emissions of the navigation signal of the pinger beacon of the autonomous bottom underwater object, the hydroacoustic signal of the ascent of the autonomous bottom underwater object, exceeding the background noise of the aquatic environment, in the reception through the receiving antenna and the necessary processing on the autonomous the bottom underwater object of the hydroacoustic ascent signal, in the termination, on the fact of reliable reception of the ascent signal, the radiation by the transmitting antenna of the autonomous bottom underwater object of the navigation on the signal of the pinger beacon, in the launch of the corresponding actuators of the system for changing the buoyancy of the autonomous bottom underwater object, modify the structure of processing the navigation signal of the pinger beacon of the autonomous bottom underwater object on the search vessel: divide the possible frequency range of concentrated interference of interfering navigation into three sub-bands - according to the maximum number interference that can be suppressed using a four-element direction finding antenna, four groups of signal processing channels are organized from four partial DF antenna receiving paths, of four receiving channels in each group, according to the “three for one” principle - to suppress concentrated interference in one, basically, the receiving channel of the group uses three corresponding auxiliary receiving channels, carried out in each group of signal processing channels, during the absence of radiation, the signal of the pinger beacon, which is briefly repeated during the hydroacoustic search, coherent compensation of oscillations of concentrated interference of the main reception channel with weighted oscillations of concentrated interference of auxiliary reception channels using the operation of adaptive complex weighting, while the signals of each auxiliary reception channel are subjected to frequency filtering in the corresponding subband of the possible frequency range of concentrated interference of interfering navigation, then linear amplitude detection and post-detection the addition of the signals of the partial reception paths of the direction finding antenna is carried out, with the appearance of the radiation of the pinger beacon, the post-detector reception of the starting message of the navigation signal, after which for a known time corresponding to the total duration of the identification message and the navigation message of the pinger beacon, the operation of the adaptive complex weighing is suspended with the saving earlier of the obtained complex weighting coefficients, receive the pinger beacon signal identification message, rea lick, after making a decision on the reliable reception of the pinger beacon signal identification message, the procedure for determining the angular coordinates of the autonomous bottom underwater object relative to the search vessel with preliminary band-pass filtering of the pinger beacon signal in the frequency band of its navigation message masked by noise and suppression of concentrated navigation interference outside the filtering band ...

Significant differences of the proposed method are the use of adaptive coherent compensation of lumped interference of disturbing navigation in the partial reception paths of the direction finding antenna performed in the pauses between the intervals of radiation of the navigation signal from the underwater object, with frequency separation of interference from different surface sources in three selected frequency subbands and the suspension of coherent compensation for the time of receiving the navigation signal of the pinger beacon, after coherent compensation of linear amplitude detection and post-detector addition of signals from the partial reception paths of the direction finding antenna, which together allows for a covert sonar search for an autonomous bottom underwater object under the influence of concentrated interference of near and long distance navigation.

The set of essential features of the proposed method has a causal relationship with the achieved technical result, from which it can be concluded that this technical solution is new, has an inventive step, since it does not explicitly follow from the existing level of technology, and is suitable for practical use.

The proposed invention is illustrated by drawings.

FIG. 1 shows an example of the occurrence of two interference from passing surface vessels during hydroacoustic search of an autonomous uninhabited bottom underwater vehicle.

FIG. 2 shows the most typical noise spectra of various surface vessels.

FIG. 3 shows the time-frequency structure of the navigation signal of the pinger beacon of an autonomous bottom underwater object.

FIG. 4 explains the structure of processing the navigation signal of the pinger beacon of an autonomous bottom underwater object on a search vessel in the process of hydroacoustic search.

FIG. 5 depicts the ratio of the frequency bands of the identification message of the navigation signal of the pinger beacon of the autonomous bottom underwater object and the possible frequency range of concentrated interference interfering with navigation.

FIG. 6 shows the enlarged functional operations of coherent compensation of lumped interference of interfering navigation in the partial reception paths of the direction finding antenna of the search vessel.

FIG. 7 shows an example of the technical implementation of a group of signal processing channels for the implementation of adaptive coherent compensation of lumped interference from disturbing navigation in each partial path for receiving the direction finding antenna of a search vessel.

FIG. 8 and FIG. 9 shows the results of modeling, according to the assessment of the energy efficiency of coherent compensation of three lumped interference interfering with navigation on a search vessel.

The procedure for the general process of a covert hydroacoustic search for an autonomous bottom underwater object of the proposed method is similar to the procedure for the prototype method, the differences are manifested in the actions of a private process - the processing of the navigation signal of the pinger beacon of an autonomous bottom underwater object on a search vessel.

The processing of the navigation signal of the pinger beacon of the autonomous bottom underwater object on the search vessel in the process of covert hydroacoustic search involves the implementation of the following order of actions, procedures and operations, which for clarity of perception are presented in the form of a graphical structure in Fig. 4.

1. The hydroacoustic signals of the aquatic environment of the search area are received by the direction-finding antenna of the diametrically-orthogonal geometry of the location of the four receiving hydrophones. Such signals are long-term fluctuation noises of the marine environment, lumped interference from interfering navigation, and a short-term navigation signal of the pinger beacon of an autonomous bottom underwater object.

2. The signals of the partial reception paths, received by the hydrophones of the direction finding antenna, are amplified to the level necessary for their further processing.

3. Carry out adaptive coherent compensation [7] of concentrated interference of interfering navigation in the partial paths of receiving direction finding antenna with the following actions and operations.

3.1. The possible frequency range of lumped interference disturbing navigation is divided into three sub-bands - according to the maximum amount of interference that can be suppressed using a four-element direction finding antenna, for frequency filtering of interference from various surface sources dispersed over the search area, the frequency spectra of which fall into the corresponding sub-bands of the possible frequency range of concentrated interference with interfering shipping.

FIG. 5 schematically shows the ratio of the frequency ranges of the broadband pinger identification message of an autonomous bottom underwater object and narrowband interference disturbing navigation, where: ΔF _s is the frequency range of the pinger identification message of an autonomous bottom underwater object; ΔF _p - possible frequency range of lumped disturbances to obstructing navigation; ΔF ₁ , ΔF ₂ , ΔF ₃ - sub-bands of frequencies of concentrated disturbances of disturbing navigation selected for frequency filtering.

In accordance with the frequency parameters of the navigation signal emitted by the pinger beacon of the autonomous bottom underwater object and the typical noise spectra of surface vessels shown in Figs. 3 and FIG. 2, as well as the preferred circuit design of the octave bandpass filters of the low-frequency range, it is possible to select the following values for the frequency range of the identification message for the navigation signal of the autonomous bottom underwater object and the frequency sub-ranges of concentrated interference of disturbing navigation: ΔF _s = 0.1 ... 8 kHz (frequency band 7.9 kHz ), ΔF ₁ = 0.1 ... 0.2 kHz (frequency band 100 Hz), ΔF ₂ = 0.2 ... 0.4 kHz (frequency band 200 Hz), ΔF ₃ = 0.4 ... 0.8 kHz (frequency band 400 Hz).

3.2. Four groups of signal processing channels are organized from four partial DF antenna receiving channels, of four receiving channels in each group, according to the “three for one” principle - to suppress concentrated interference in one main receiving channel of the group, three corresponding auxiliary receiving channels are used.

3.3. In each group of signal processing channels, during the absence of radiation, which is briefly repeated in the process of hydroacoustic search for the navigation signal of the pinger beacon of an autonomous bottom underwater object, coherent compensation of oscillations of concentrated interference of the main reception channel by weighted oscillations of concentrated interference of auxiliary reception channels using the operation of adaptive complex weighing is carried out, in this case, the signals of each auxiliary reception channel are subjected to frequency filtering in the corresponding sub-band of the possible frequency range of lumped interference interfering with navigation.

Coherent compensation of concentrated interference in the partial reception paths of a DF antenna with a three-for-one constellation can be represented by the enlarged functional operations shown in FIG. 6, where are indicated: 1 - amplification of signals of partial reception paths of the direction finding antenna, 2 - frequency filtering of interference oscillations in the frequency subband ΔF ₁ , 3 - frequency filtering of interference oscillations in the frequency subband ΔF ₂ , 4 - frequency filtering of interference oscillations in the frequency subband ΔF ₃ , 5 - formation of complex weighting coefficients for coherent compensation of interference oscillations in the corresponding partial reception path, 6 - complex weighting of interference oscillations of the corresponding partial reception paths of three frequency subbands, 7 - subtraction from the interference oscillations of the corresponding partial reception path of weighted interference oscillations of three frequency subbands the range of lumped interference obstructing navigation.

An example of the technical implementation of a group of signal processing channels for the implementation of adaptive coherent compensation of lumped interference from interfering navigation in each partial path for receiving a direction finding antenna of a search vessel is shown in Fig. 7, where indicated: F1, F2, F3 - band pass filters with frequency bands ΔF ₁ , ΔF ₂ , ΔF _3, respectively; KP - quadrature signal converters; P1 - signal multipliers; P2 - signal multipliers with limit limitation of the multiplied signals; And - managed integrators; С - signal adder; Inv - signal inverter.

Shown in FIG. 7 functional linkages structure of elements of the signal processing channels implements adaptive coherent compensation signals arriving at input 1, the weighted signals are applied to inputs 2, 3, 4, the method of steepest gradient descent [7], with the formation of the corresponding coefficients W ₁ ... W ₆ complex weighing. To implement adaptive coherent compensation of concentrated interference in the receiving paths of the direction finding antenna of the search vessel, connections of Inputs 1-4 of each of the four groups of signal processing channels to the corresponding receiving paths of the direction finding antenna are organized. The order of connections is shown in table. one.

4. After coherent compensation of concentrated interference of interfering navigation, linear amplitude detection and post-detector addition of signals from partial reception paths of the direction finding antenna are performed in order to ensure that the signal-to-noise ratio is sufficient for reliable reception of the parcel to identify the navigation signal of the pinger beacon of the autonomous bottom underwater object.

5. With the appearance of the radiation of the pinger beacon of the autonomous bottom underwater object, the post-detection reception and processing of the starting message of the navigation signal are carried out.

6. After receiving and processing the starting message of the navigation signal (see the functional operation in Fig. 6 and the signal from the receiver of the starting message in Fig. 7), the operation is suspended for a known time corresponding to the total duration of the identification message and the navigation message of the pinger beacon. adaptive complex weighing with preservation of the previously obtained complex weighting coefficients, which makes it possible to avoid suppression, as a result of coherent compensation, of the received message of identification of the navigation signal of the pinger beacon of the autonomous bottom underwater object.

7. Receiving and processing the identification message of the navigation signal of the pinger beacon of the autonomous bottom underwater object is carried out.

8. The procedure for determining the angular coordinates of the autonomous bottom underwater object relative to the search vessel with preliminary band-pass filtering of the pinger beacon signal in the frequency band of its noise-masked navigation message and suppression of out-of-band filtering of lumped traffic interferences.

The principle of receiving the starting message and sending the identification of the navigation signal of the pinger beacon of the autonomous bottom underwater object, the functional composition and technical implementation of the equipment necessary for this are similar to the algorithmic and hardware attributes used in the prototype method.

Possible technical implementation of the equipment of the search vessel and the autonomous bottom underwater object of the proposed method coincides with the technical implementation of the equipment of the said objects of the prototype method.

Examples of possible circuitry implementation of functional elements of a group of signal processing channels with coherent compensation of lumped interference from interfering navigation in the partial reception paths of the direction finding antenna of a search vessel are presented in Table. 2.

Circuit design of bandpass filters for frequency filtering of the pinger beacon signal in the partial reception paths of the direction finding antenna in the frequency band of its noise-masked navigation message is similar to the design of bandpass filters [8] for filtering the interference of three frequency sub-bands of the possible frequency range of concentrated interference interfering with navigation.

The interference suppression of interfering navigation is based on the principle of space-time processing [13] of the navigation signal of the pinger beacon of an autonomous underwater object with adaptive coherent compensation of concentrated interference in the partial reception paths of the direction finding antenna of a search vessel, using spatial, temporal and frequency differences in the navigation signal and interfering interference ...

Let us estimate the energy efficiency of spatio-temporal processing for the case of coherent compensation of three lumped interference disturbing navigation, which characterizes the worst scenario of a covert hydroacoustic search for an autonomous bottom underwater object from a search vessel.

Before proceeding to a quantitative assessment of the energy efficiency parameters, it should be noted that the coherent compensation of disturbing navigation interference is aimed at suppressing narrow-band disturbing navigation interference with the provision of the required reliable reception of a broadband pulse signal for the identification of a pinger beacon of an autonomous uninhabited bottom underwater object.

Therefore, the coefficients of the complex weighting of the oscillations of the partial reception paths of the direction finding antenna of the search vessel, formed with coherent compensation of narrow-band interference of interfering navigation, make it possible, on the one hand, to effectively suppress them, but, on the other hand, lead to distortions of the shape of the broadband signal of the pinger beacon identification message , due to changes in the levels of its spectral components, which can lead to a decrease in the reliability of the subsequent reception.

In this regard, in order to approximately estimate the permissible distortions of the shape of the broadband signal of the identification message of the pinger beacon in the partial reception paths of the direction finding antenna (after coherent compensation of interference), the parameters of the energy efficiency of space-time processing will be determined at several frequencies of its spectrum.

In the mathematical description of the operations of coherent compensation of narrow-band interference, a natural question arises of choosing the form of presentation of interference interfering with navigation (hereinafter referred to as interference) and the signal for sending the identification of a pinger beacon of an autonomous bottom underwater object (hereinafter referred to as a signal), which must be reliably received on a search vessel under the influence of these interference and fluctuation noise of the marine environment.

The form of signal and noise representation should help to reduce the cumbersomeness of the used mathematical transformations, in order to eliminate possible errors in calculations, to reflect the parameters of real signals and interference to the necessary extent during the hydroacoustic search from a surface ship of an autonomous bottom underwater object, and not lead to an unacceptable distortion of the final results due to the introduced mathematical assumptions.

Taking into account the necessary correctness of mathematical transformations and physical features of the used hydroacoustic communication channel, we introduce the following assumptions:

- the signal and interference in the four partial reception paths of the direction finding antenna are represented by complex numbers in exponential form, while the modulus of the complex number is interpreted as the amplitude of the real signal, and the imaginary argument (the angle of inclination of the vector relative to the real axis on the complex plane) is interpreted as its phase, from the form presentation excludes two components - frequency and time;

- the levels of the received signal, interference and fluctuation noise of the marine environment in each partial path of the DF antenna are assumed to be the same, respectively, this is due to the small spatial spacing of the DF antenna receiving hydrophones;

- fluctuation noises of the marine environment in the partial reception paths of the direction finding antenna are considered uncorrelated, this physical aspect of the formation of marine environment noise, for the frequency range used in the claimed method, is confirmed by experimental studies;

- there are no correlations between the signal and interference in the partial reception paths of the direction finding antenna, due to the independence of the sources generating them.

Let us write down the signal-interference processes in the first (main) partial channel for receiving the direction finding antenna of a search vessel in the following form, suitable for further transformations,

- дисперсия флуктуационного шума морской среды.where X ₁ , Y ₁ , Y ₂ , Y ₃ are the amplitudes of the signal and three disturbances, respectively; ψ ₁ , ϕ ₁ , ξ ₁ , φ ₁ are the phases of the signal and three hindrances due to the spatial separation of the sources of the signal and hindrances, as well as the hydrophones of the direction finding antenna of the search vessel;

- dispersion of fluctuation noise of the marine environment.

Signal-interference processes in auxiliary partial reception paths (second, third and fourth) are presented, respectively:

where ΔF _s is the signal frequency band; X ₂ , X ₃ , X ₄ - signal amplitudes after frequency filtering in the frequency sub-bands ΔF ₁ , ΔF ₂ , ΔF _3, respectively; ψ ₂₁ - Phase of the signal of the second partial receiving path after frequency filtering in the frequency subband ΔF ₁ ; ψ ₃₂ - phase of the signal of the third partial receiving path after frequency filtering in the frequency sub-band ΔF ₂ ; ψ ₄₃ - the phase of the signal of the fourth partial receiving path after frequency filtering in the frequency sub-band ΔF ₃ ; ϕ ₂ is the phase of the first interference of the second partial receiving path after frequency filtering in the frequency subband ΔF ₁ ; ξ ₃ - phase of the second interference of the third partial receiving path after frequency filtering in the frequency sub-band ΔF ₂ ; φ ₄ - the phase of the third interference of the fourth partial receiving path after frequency filtering in the frequency subband.

The diagonal square matrix A of correlations of interference fluctuations (three uncorrelated interference disturbing navigation and fluctuation noise of the marine environment) of the second, third and fourth partial paths for receiving the direction finding antenna has the form

The vector S of correlations of interference oscillations of the first and second, first and third, first and fourth partial paths of receiving the direction finding antenna will be written accordingly:

Determine the elements of the inverse matrix A ^{-1 of} correlations of interference oscillations of the second, third and fourth partial paths of receiving the direction finding antenna:

Let us denote the interference / fluctuation noise ratio in the partial reception paths of the direction finding antenna:

then the complex weighting coefficients for coherent compensation of interference oscillations in the main partial reception path with weighted interference oscillations of the auxiliary (second, third and fourth) partial reception paths, which are formed in the group of signal processing channels (see Fig. 7) after completion of the adaptation process by the method of the fastest gradient descent, we find on the basis of the matrix Wiener-Hopf equation known in the theory of adaptive signal processing [13] from the relations:

which, taking into account dependencies (4) and (5), are converted to the form

The level of interference oscillations, for their coherent compensation in the main receiving path, is determined by the sum of weighted oscillations of three auxiliary receiving paths:

The power of the uncompensated residual of interference in the main receiving path of the direction finding antenna as a result of performing coherent compensation is:

- помехи основного парциального тракта приема; * - знак комплексного сопряжения.where

- interference of the main partial receiving path; * - complex conjugation sign.

The increased, as a result of coherent compensation, the variance of the fluctuation noise of the marine environment of the main partial path for receiving the direction finding antenna is determined by the ratio:

Let us introduce additional designations:

where α ₁ , α ₂ , α ₃ , α ₄ are the signal-to-fluctuation noise ratios in the partial reception paths of the direction finding antenna.

In this case, the signal-to-noise ratio (SNR) in each of the four partial reception paths of the direction finding antenna after coherent compensation will be described by the following relationship:

where i = 1, 2, 3, 4 is the number of the partial receiving path; H _i [dB] is the reduction factor of the signal power in the partial receiving path by reducing the amplitudes of the spectral components in the frequency subbands ΔF ₁ , ΔF ₂ , ΔF _{3 for} filtering interference after the operation of subtracting signals.

FIG. 8, as an example, shows the dependences of the signal-to-noise ratio on the interference / fluctuation noise ratio for different signal-to-fluctuation noise ratios with coherent compensation of three narrow-band noise, calculated using dependence (11), with the following parameters of signal-noise processes in partial paths DF antenna reception: H ₁ = H ₂ = H ₃ = H ₄ = 3 dB; α ₁ = α ₂ = α ₃ = α ₄ = 10, 20, 30 dB; ΔF ₁ = 100 Hz; ΔF ₂ = 200 Hz; ΔF ₃ = 400 Hz; ΔF _s = 7.9 kHz; β ₁ = β ₂ = β ₃ = 1… 100 dB. In this case, we have GSP ₁ = GSP ₂ = GSP ₃ = GSP ₄ .

As seen in FIG. 8, the signal-to-noise ratios in the four partial reception paths of the direction-finding antenna after coherent compensation do not depend on the interference / fluctuation noise ratios and are determined by the signal-to-fluctuation noise ratios _{reduced by the values of the signal power reduction coefficients H 1} , H ₂ , H ₃ , H _4.

To determine the values of the coefficients H ₁ , H ₂ , H ₃ , H _{4 of the} decrease in the signal power in the partial reception paths of the direction finding antenna after coherent compensation, it is necessary to know the spectral density of the signal of the identification message of the pinger beacon of an autonomous bottom underwater object in the frequency range ΔF _s , which will be characterized by the spectral composition of the sound recordings of the marine environment selected for masking sonogram fragments.

For a quantitative assessment of the possible reduction in the power of the spectral components of the signal in the frequency range ΔF _{p of} interference to shipping, one can use analytical expressions obtained within the framework of the used mathematical model of signal-interference processes in the partial reception paths of the direction finding antenna:

where

H _ij (i = 1, 2, 3, 4; j = 1, 2, 3) is the power reduction factor of the signal of the i-th partial receiving path in the j-th sub-band of shipping interference frequencies; i is the number of the partial path for receiving the direction finding antenna; j is the number of the frequency sub-band of shipping interference.

In order to assess the decrease in the power of the spectral components of the signal in the partial reception paths, based on relations (12) - (15), calculations were made for the following characteristics of the process of covert hydroacoustic search for an autonomous bottom underwater object:

- the search vessel uses a direction finding antenna of diametrically-orthogonal geometry with dimensions of 0.2 m and 0.1 m in the horizontal and vertical planes, respectively, with an inclined distance to the autonomous bottom underwater object (signal source) of 500 m;

- there is an effect of three narrow-band disturbances to shipping with the central frequencies of the spectra of 150, 300 and 600 Hz;

- the frequencies of the spectral components of the signal for the identification of the pinger beacon of the autonomous bottom underwater object are taken equal to the central frequencies of the interference spectra;

- bearings of sources of interference (interfering surface vessels) relative to the course of the search vessel are - for the first interference 60 °, for the second 140 °, for the third 240 °;

- the elevation angle of the signal source (autonomous bottom underwater object) relative to the water surface of the search area is taken equal to 70 °;

- the elevation angles of the sources of interference (places of reflection from the seabed of acoustic vibrations of interfering surface vessels) are chosen equal - for the first interference 10 °, for the second 20 °, for the third 30 °;

- slope distances to sources - the first interference is 5000 m, the second interference is 3000 m, the third interference is 1000 m;

- the interference / fluctuation noise ratios β ₁ , β ₂ , β ₃ in the partial reception paths of the direction finding antenna are taken - for the first interference 40 dB, for the second 30 dB, for the third 20 dB;

- the frequency band ΔF _{s of the} navigation signal of the pinger beacon of the autonomous bottom underwater object is 7.9 kHz;

- bands ΔF ₁ , ΔF ₂ , ΔF ₃ for frequency filtering of interference to navigation are chosen equal to 100, 200 and 400 Hz, respectively;

- the sought-for power reduction factors of the spectral components of the signal in the partial reception paths are investigated as functions of all possible bearings (0 °… 360 °) of the signal source during the hydroacoustic search of an autonomous bottom underwater object.

The calculations made it possible to identify:

- a significant scatter of values and a different nature of changes in the power reduction factors of the spectral components of the signal along the partial reception paths of the direction finding antenna;

- significant changes in the power reduction factors depending on the bearing of the signal source.

The corresponding calculations also showed that, despite significant changes in the power reduction factors, their spread and different nature of changes along the partial reception paths of the direction finding antenna, due to the introduction of linear amplitude detection with post-detector addition of partial signals, after coherent compensation, the complete suppression of the spectral components of the signal at the interference frequencies shipping.

This is illustrated by the dependences of the signal-to-noise ratios for three spectral components of the signal (150, 300, and 600 Hz) after the post-detector addition operation, obtained for the above conditions of covert hydroacoustic search for an autonomous bottom underwater object and shown in Fig. 9. The signal-to-fluctuation noise ratio for the indicated spectral components of the signal in the partial reception paths is taken equal to 30 dB.

From FIG. 9, it can be seen that after the post-detector addition operation there is no complete suppression of the indicated spectral components of the signal, depending on the change in the bearing of the signal source, which confirms the advisability of introducing this operation after the implementation of coherent compensation of navigation interference in the process of covert sonar search for an autonomous bottom underwater object.

Suppression of interference to navigation with the use of coherent compensation in the process of covert hydroacoustic search is carried out under the conditions of a wide variety of relative movements of the search and interfering vessels in the water area of the search for an autonomous uninhabited bottom underwater object.

Since the coherent compensation of interference to navigation assumes for a certain time corresponding to the total duration of the identification message and the navigation message of the pinger beacon, the suspension of the adaptive complex weighing while maintaining the previously obtained complex weighting coefficients, this action under the conditions of relative movements of the search and interfering vessels can lead to a decrease in the ratio signal / noise after coherent compensation. This is due to the changes in the phase relationships of interference oscillations in the partial reception paths of the direction finding antenna that appear due to the movements of the search and interfering vessels, which differ from the phase relationships that determine the coefficients of the optimal complex weighting, which leads to an increase in the uncompensated residual of interference and a decrease in the signal / interference ratio after coherent compensation ...

The basic parameter of the spatial movement of surface objects can be the maximum change in the bearings of interfering vessels relative to the search vessel during the time it receives the navigation signal of the pinger beacon of the autonomous bottom underwater object, which depends on the course of the vessels, the distance between the vessels and the speeds of their movement.

The worst scenario of a covert hydroacoustic search for an autonomous underwater bottom object is the movement of the search vessel and the interfering vessels in parallel collision courses with the movement of the disturbing vessels from the traverse of the search vessel. Such movement of vessels leads to the maximum, for the selected observation time, a change in the bearings of interfering ships relative to the search one, characterizing the worst conditions for the impact of interference with interfering navigation.

Calculations of the signal-to-noise ratio after coherent compensation of interference in the partial paths of receiving the direction finding antenna at maximum changes in the bearings of the interfering vessels relative to the search vessel, during the time it receives the navigation signal of the pinger beacon of an autonomous underwater object, in the specified scenario of the movement of the search and disturbing vessels with the following initial data:

- the duration of the navigation signal of the pinger beacon of the autonomous bottom underwater object was chosen equal to 2.2 seconds in accordance with the recommendations [4] to ensure effective covert hydroacoustic search;

- the maximum speed of the search vessel is taken equal to five knots, which also corresponds to the recommendations [4] to ensure the required positioning accuracy of the autonomous bottom underwater object;

- the range of speeds of movement of interfering vessels (from drift to 40 knots) is selected on the basis of data [14] on the most common speeds of movement of modern surface vessels of various technological devices and purposes;

- the traverse distance of 0.3 miles between the search and interfering vessels is set from considerations of assessing the maximum change in bearing at a possible critical distance between vessels, taking into account the rules [15] for preventing collisions of vessels at sea.

The obtained calculation results indicate that there is no decrease in the signal-to-noise ratio after coherent compensation of interference in the partial reception paths of the direction finding antenna in the worst scenario of a covert hydroacoustic search for an autonomous bottom underwater object in conditions of movement of surface interfering vessels at speeds up to 40 knots.

Such results are explained by very insignificant changes in the phase ratios of interference oscillations in the partial paths of receiving the direction finding antenna, with the relative movements of the search and interfering vessels, due to the small linear dimensions of the direction finding antenna of the search vessel in comparison with the distances to the sources of interference - the places where acoustic vibrations of interfering surface vessels are reflected from the sea. bottom.

Thus, the proposed technical solution makes it possible to achieve the desired effect - the implementation of a covert hydroacoustic search for an autonomous bottom underwater object from a surface search vessel under the influence of interference to navigation, due to the previously unused combination: the use of coherent compensation of concentrated interference of interfering navigation in search vessel, performed in the pauses between the intervals of radiation of the navigation signal from the underwater object, which includes frequency separation of interference from different surface sources in three selected frequency subbands, complex weighting in the selected subbands of oscillation frequencies of concentrated interference of the corresponding partial paths for receiving the direction finding antenna, subtraction from oscillations of concentrated interference of each main partial channel for receiving three corresponding auxiliary partial reception paths, suspension of coherent compensation for the time of receiving the navigation signal of the pinger beacon, after coherent compensation of linear amplitude detection and post-detector addition of signals from the partial reception paths of the direction finding antenna, which together makes it possible to realize reliable reception of the navigation signal of an autonomous bottom underwater an object on a search vessel in conditions of obstruction of interfering navigation.

This set of features of a new technical solution distinguishes the proposed method from the currently known methods of hydroacoustic positioning of underwater objects.

List of sources used

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Claims (1)

A method of covert hydroacoustic search from a surface search vessel for an autonomous bottom underwater object in a dormant mode at the bottom of a known sea area after completing a corresponding mission, which consists in equipping a search vessel with a direction finding antenna, a diametrically orthogonal geometry of the location of four receiving hydrophones, a weakly directional transmitting hydroacoustic antenna, equipment for receiving and processing the navigation signal of the pinger beacon of an autonomous bottom underwater object based on a highly stable reference generator, equipment for generating activation signals and ascent of an autonomous bottom underwater object, a hydroacoustic echo sounder for measuring the depth of the search water area with a structure of probing pulses, which allows to provide acoustic perception of the measurement procedure depths of the search water area, approaching a possible hybrid noise background of the marine environment, equipped with an autonomous bottom th underwater object by a buoyancy change system, weakly directional receiving and transmitting hydroacoustic antennas, equipment for receiving and processing signals for activation and ascent of a search vessel, a pinger beacon that generates, using a highly stable reference generator, a repetitive navigation signal, in formation and memorization when preparing a mission for an autonomous underwater of an object on an underwater object and a search vessel signals emitted during the hydroacoustic search process: on an autonomous underwater object - a navigation signal of a pinger beacon, on a search vessel - activation and ascent signals of an autonomous underwater bottom object having a given structure, amplitude, time and frequency parameters, according to acoustic perception of a known search area approaching possible background noises, while the activation and surfacing signals of the search vessel consist of two components: the starting message and the identification message, and the navigation signal of the pinger beacon of an autonomous bottom underwater object contains four components: a starting message, an identification message, a navigation message in the form of a harmonic signal of the frequency known on the search vessel, and a quasi-white noise masking the navigation message, the frequency parameters of which ensure the necessary accuracy in determining the angular coordinates of an autonomous bottom underwater object relative to the search vessel in the process its hydroacoustic search, in addition, the structure and parameters of the emitted navigation signal of the beacon-pinger of the autonomous bottom underwater object are a priori known on the search vessel, and the structure and parameters of the emitted signals of activation and surfacing of the search vessel are a priori known on the autonomous bottom underwater object, when performed before the search procedure calibration of partial paths for receiving the navigation signal of the search vessel with the receipt and storage of calibration corrections, in repetitive, as the search vessel moves through the search water area, from its radiation by a transmitting antenna into the aquatic environment of the lower hemisphere space, relative to the search vessel, the hydroacoustic signal of activation of the autonomous bottom underwater object, exceeding the background noise of the aquatic environment of the search area, in receipt by the receiving antenna and the necessary processing on the autonomous bottom underwater object of the sonar activation signal of the search vessel, in the translation of the equipment of the autonomous bottom underwater object, on the fact of reliable reception of the activation signal, from the sleeping mode to the operating mode, in the radiation of the transmitting antenna of the autonomous bottom underwater object into the aquatic environment of the search area in the directions of the upper hemisphere, relative to the seabed, a hydroacoustic navigation signal exceeding the background noise aquatic environment, formed by a pinger beacon and repeated with an interval longer than its duration, in the reception of the navigation signal of the pinger beacon by the direction finding antenna of the search vessel and its corresponding processing the subsequent termination, upon the fact of its reliable reception, of the emission by the transmitting antenna of the search vessel of the hydroacoustic signal of activation of the autonomous bottom underwater object, in the measurement and memorization of the depth of the water area of the search by the echo sounder of the search vessel, in the implementation, in the search process, on the search vessel of the procedure for determining and storing angular coordinates of an autonomous bottom underwater object relative to a search vessel, consistent with the geometric parameters of a direction finding antenna and allowing positioning of an autonomous bottom underwater object relative to a search vessel with the required accuracy in conditions of low signal / masking noise ratios of the navigation message of the pinger beacon, in the assessment and storage of a certain elevation angle and the measured depth of the water area of the search for approximate values of the range and slope distance to the autonomous bottom underwater object using the corresponding trigonometric ratios, in correcting the course the position of the search vessel based on the updated parameters of the location of the autonomous bottom underwater object relative to the search vessel as it moves through the search water area to a predetermined safe surfacing range of the autonomous bottom underwater object, in the radiation of the transmitting antenna of the search vessel into the aquatic environment of the search water area, in the space of the lower hemisphere, relative to the search vessel, in the pause between the emissions of the navigation signal of the pinger beacon of the autonomous bottom underwater object, the hydroacoustic signal of the ascent of the autonomous bottom underwater object, exceeding the background noise of the aquatic environment, in the termination, upon the fact of reliable reception of the ascent signal, the radiation by the transmitting antenna of the autonomous bottom underwater object of the navigation signal of the pinger beacon, in the launch of the corresponding executive mechanisms of the system for changing the buoyancy of an autonomous bottom underwater object, characterized in that they modify the structure of processing the navigation signal of the pinger beacon of an autonomous bottom underwater object on a search vessel: they divide the possible frequency range of concentrated interference disturbing navigation into three sub-bands - according to the maximum amount of interference that can be suppressed from using a four-element direction-finding antenna, four groups of signal processing channels are organized from four partial receiving paths of a direction-finding antenna, out of four receiving channels in each group, according to the "three for one" principle - to suppress concentrated interference in one, main, group receiving channel, three corresponding auxiliary reception channels are carried out in each group of signal processing channels, during the absence of radiation, which is briefly repeated in the process of hydroacoustic search for a pinger beacon signal, coherent compensation of oscillations is strong interference of the main reception channel by weighted oscillations of concentrated interference of auxiliary reception channels using the operation of adaptive complex weighting, while the signals of each auxiliary reception channel are subjected to frequency filtering in the corresponding subband of the possible frequency range of concentrated interference of interfering navigation, then linear amplitude detection and post-detector addition of signals of partial paths for receiving the direction finding antenna, with the appearance of the radiation of the pinger beacon, the post-detector reception of the starting message of the navigation signal is carried out, after which, for a known time corresponding to the total duration of the identification message and the navigation message of the pinger beacon, the operation of the adaptive complex weighing is suspended with the preservation of the previously obtained complex coefficients weighing, receive the pinger beacon signal identification message, implement, after making a decision on the valid On receiving the pinger beacon signal identification message, the procedure for determining the angular coordinates of an autonomous bottom underwater object relative to the search vessel with preliminary bandpass filtering of the pinger beacon signal in the frequency band of its navigational message masked by noise and suppression of concentrated navigation disturbances outside the filtering band.

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