RU2249233C1 - Method of finding poaching fishing tools placed on ground or inside bottom layer of deposits - Google Patents

Abstract

FIELD: fishery underwater acoustics.

SUBSTANCE: vessel being involved in finding poaching fishing tool tows underwater apparatus by means of cable-rope. There is satellite navigation system on the vessel which allows high-precision determining coordinates of vessel. There is also computer on the vessel providing control for operation of all sections disposed on vessel and in towed underwater apparatus. Computer finally solves the problems of efficient finding, detecting, identifying and determining of space coordinates of poaching fishing tools located on ground or bottom deposit layer. Sea biological objects generate wide-band signals which objects sit in traps connected to each other by halyard.

EFFECT: improved efficiency of finding.

9 dwg

Description

The invention relates to the field of field sonar and can be used in the fishing industry to search for unmarked (poaching) fishing gear located on the ground and in the bottom sediment layer.

The problem that is solved by the invention is the effective search, recognition and determination of the spatial coordinates of unmarked (poaching) fishing gear located on the ground and in the bottom sediment layer, in the interest of ensuring the rational use of marine biological resources.

The method is implemented as follows.

A vessel searching for an unmarked fishing gear is towed by an underwater vehicle using a cable. There is a satellite navigation system on the vessel, which allows to determine the coordinates of the vessel in space with high accuracy, as well as an electronic computer (PC), which provides control of the operation of all paths on the vessel and in the towed underwater vehicle (BPA). In addition, the computer ultimately solves the problems of efficient search, detection, recognition and determination of the spatial coordinates of unmarked fishing gear located on the ground and in the bottom sediment layer. At the same time, marine biological objects (MBO) are located in traps connected with each other by means of a special halyard, emitting in the process of their activity broadband signals Ω _b .

In the path of parametric emission of broadband signals using a series-electrically connected pump signal generation block at frequencies ω ₃ and ω ₄ , a second power amplifier and a second emitter of high-frequency (RF) pump signals, the RF pump signal is generated, amplified to the required level, and emitted into the aqueous medium at frequencies ω ₃ and ω ₄ . In the aquatic environment, a broadband wave of difference frequency Ω ₂ = ω ₃ -ω ₄ is generated, with the help of which the entire water column is located from the surface to the bottom.

In the continuous emission path of an intense RF pump signal using a series-electrically connected signal generation unit at a pump frequency ω _n1 , a third power amplifier and a third RF pump signal emitter, an RF pump signal is generated, amplified to the required level, and emitted into an aqueous medium at a frequency ω _n1 close to the subharmonic of the resonant frequency of air bubbles ω ₀ located in the surface water layer in the region of the location of the third radiator of the RF pump signal. In an aqueous medium, a nonlinear interaction of the backward-scattered RF pump wave ω ' _{n1 occurs} with the broadband wave Ω' ₂ reflected from the inhomogeneities (sound diffusers located throughout the water column) of the aqueous medium. In this case, an RF wave is generated at the combination frequency ω ' _n1 ± Ω' ₂ , which is received using the first RF receiver located in the lower part of the ship's hull, the path of parametric reception of broadband signals. Next, the RF signal at the combination frequency ω ' _n1 ± Ω' _{2 is} fed to the input of the filter unit, where RF interference is suppressed. From the output of the filter block the RF signal at the combination frequency ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{n1}}$ ± Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{2}}$ arrives at the corresponding signal processing unit, in which the useful broadband signal Ω ′ _{2 is extracted} from the RF signal at the combination frequency ω ′ _n1 ± Ω ′ ₂ by the detection method. From the output of the processing unit, the broadband signal Ω ' _{2 is} fed to the input of the computer, where it is compared with the reference signal Ω ₂ and a decision is made on the spatial (resonance frequency, length, etc.) and acoustic (resonant frequency, layer strength, etc.) sound-scattering characteristics layers (ZRS) located in the water column (carried out acoustic spectroscopy of sound diffusers). Based on the results obtained, the towing horizon of the underwater vehicle is set equal to the upper boundary of the layer of deep biological air defense systems or the upper boundary of the layer of bottom biological air defense systems.

In this case, in the path of parametric radiation relative to broadband signals, using the series-connected electrically generated block for generating the RF pump signals at frequencies ω ₁ and ω ₂ , the first power amplifier and the first radiator of the RF pump signals at frequencies ω ₁ and ω ₂ , the formation is amplified to the required level and radiation of the RF pump signal at frequencies ω ₁ and ω ₂ close to the resonant frequency ω _{0 of} air bubbles located in the surface water layer in the region of the location of the first radiator of the RF signal Pumps ω ₁ and ω ₂ . A relatively broadband wave of difference frequency Ω ₁ = ω ₁ -ω ₂ is generated in the aquatic environment, with the help of which the bottom is located over a large area, including an unmarked fishing gear located on the ground and in the bottom layer of sediments at different angles to the direction of travel vessel. In the path of parametric radiation of relatively narrow-band and less intense signals, the formation and amplification to the necessary level are carried out using a series-electrically connected unit for generating high-frequency pump signals at frequencies ω ₅ and ω ₆ , a fourth power amplifier and a fourth radiator for high-frequency pump signals at frequencies ω ₅ and ω ₆ level and radiation into the aqueous medium of HF pump signals at frequencies ω ₅ and ω ₆ . In the aquatic environment, a wave is generated with respect to the narrow-band difference frequency Ω ₃ = ω ₅ -ω ₆ , it is used to locate an unmarked fishing gear (at a shorter range, in narrow solid angle, at the optimal course of movement of the towed underwater vehicle, etc.), the reflected wave of the difference frequency Ω ' _{3 is} received and more reliably (in the final case) unmarked fishing gears are recognized and their coordinates are more accurately determined.

In the path of continuous radiation of a less intense RF pump signal using a series-electrically connected pump signal generation block at a frequency of ω _n2 , a fifth power amplifier and a fifth RF pump signal emitter, the RF pump signal is generated, amplified to the required level, and emitted at a frequency of ω _n2 close to the resonant frequency ω _s of the sound diffusers that dominate the horizon of the towed underwater vehicle in the area of the fifth emitter of the RF pump signal.

In an aqueous medium, a nonlinear interaction of backward-scattered RF pump waves ω ' _n1 and ω' _{n2 occurs} with reflected waves at difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ , as well as noise emission Ω _b MBO, and RF waves are generated at combination frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₂ , ω ' _n1 ± Ω' ₃ , ω ' _n1 ± Ω _b , ω' _n2 ± Ω ' ₁ , ω' _n2 ± Ω ' ₂ , ω ' _n2 ± Ω' ₃ , ω ' _n2 ± Ω _b , which are respectively received using the first RF receiver of the path for parametric reception of broadband signals and with the help of the second RF receiver of the highly directional couple path metric reception of broadband signals. Further, the RF signals at the combination frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₃ and ω ' _n1 ± Ω _b are fed to the inputs of the respective filter units where RF interference is suppressed. From the output of the filter block, the RF signals at the combination frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₃ and ω ' _n1 ± Ω _b are fed to the inputs of the corresponding signal processing units, in which the selection of useful broadband signals Ω' ₁ , Ω ' ₃ and Ω _b from the HF signals at the combination frequencies ω' _n1 ± Ω ' ₁ , ω' _n1 ± Ω ' ₃ and ω' _n1 ± Ω _b by the detection method. From the outputs of the signal processing units, the broadband signals Ω ′ ₁ , Ω ′ ₃ and Ω _b are fed to the input of the computer. At the same time, the signals at the high-frequency combination frequencies ω ' _n2 ± Ω' ₁ , ω ' _n2 ± Ω' ₂ , ω ' _n2 ± Ω' ₃ , ω ' _n2 ± Ω _b come from the output of the second high-frequency receiver to the input of the multi-channel filter block, where the suppression of RF interference on each channel (each RF combinational frequency) is carried out. From the output of the filter block, the RF signals at the combination frequencies ω ' _n2 ± Ω' ₁ , ω ' _n2 ± Ω' ₂ , ω ' _n2 ± Ω' ₃ , ω ' _n2 ± Ω _b are fed to the corresponding inputs of the multi-channel signal processing unit, in which the broadband signals Ω ' ₁ , Ω' ₂ , Ω ' ₃ and Ω _{b are extracted} from the RF signals at the combination frequencies ω' _n2 ± Ω ' ₁ , ω' _n2 ± Ω ' ₂ , ω' _n2 ± Ω ' ₃ , ω' _H2 ± Ω _b by the detection method. From the output of the multi-channel signal processing unit, useful broadband signals Ω ′ ₁ , Ω ′ ₃ and Ω _b are fed to the input of the computer.

At the same time, in the path of linear reception of broadband signals using a serially connected broadband receiver located at the bottom of the towed underwater vehicle, a multi-channel filter unit and a multi-channel unit for processing broadband signals, the reflected signals are received, filtered and processed at difference frequencies Ω ' ₁ , Ω ' ₂ and Ω' ₃ , as well as noise emissions Ω _b MBO located in an unmarked fishing gear. In a computer, all useful signals Ω ' ₁ , Ω' ₃ and Ω _{b are} compared with the reference signals Ω ₁ , Ω ₃ and Ω _b and the final decision is made on the detection, identification and determination of the spatial coordinates of the unmarked (bacon) fishing gear located on the ground and in the bottom sediment layer (9 silt).

A known method for the detection of marine objects (including biological), which consists in the formation, amplification and radiation into the aquatic environment of hydroacoustic signals; propagation of hydroacoustic signals, including towards the marine object; receiving and identifying sonar signals that have passed through the aquatic environment and reflected from the marine object, as well as deciding on its detection and determining the spatial coordinates of the object [1].

The disadvantages of this method include:

1. The difficulty of detecting a marine object with negligible reflectivity (for example, discharged accumulations of fish, accumulations of invertebrates, fishing gear, etc.).

2. The inability to detect a marine object (for example, fishing gear) located in the bottom layer of sediment.

3. Insignificant range, due to the low signal to noise ratio (C / P), especially in conditions of surface and bottom reverb, at the output of the receiving part of the device.

4. Low reliability of recognition of a marine object.

There is a method of searching and identifying marine objects (including biological) by the characteristic noise emitted by them, which consists in the formation and emission of hydroacoustic signals of a biological nature into the aquatic environment; the propagation of hydroacoustic signals of a biological nature in the aquatic environment, including towards the receiving part of the device; receiving and recognizing hydroacoustic signals of a biological nature that have passed through the aquatic environment, as well as determining their spatial coordinates and deciding on the detection of marine objects [2].

The disadvantages of this method include:

1. The difficulty of detecting a marine object with a low level of underwater noise and signals (for example, discharged accumulations of fish, accumulations of invertebrates, etc.).

2. The inability to detect a marine object (for example, fishing gear), including those located in the bottom layer of sediment.

3. A small range due to the low signal to noise ratio (C / P), especially in conditions of increased sea noise (due to sea waves, etc.) at the output of the receiving part of the device.

4. Low reliability of recognition of a marine object.

There is a method of generating directed low-frequency (LF) radiation of signals in an aqueous medium based on the laws of parametric conversion of RF pump waves in a non-linear aqueous medium. The method consists in irradiating the aquatic environment with ultrasonic signals at close frequencies and forming in the aquatic environment highly directional radiation of a difference frequency wave (VChF) propagating in the direction of the marine object; receiving and identifying hydroacoustic signals of HFV that passed through the aquatic environment and reflected from the marine object, as well as determining the spatial coordinates of marine objects and deciding on their detection [3].

The disadvantages of this method include:

1. The low efficiency of the method due to the small value of the coefficient of conversion of the acoustic energy of the high-frequency pump waves into the acoustic energy of the low-frequency wave of the difference frequency.

2. The difficulty of detecting a marine object with a low level of underwater noise and signals (for example, discharged accumulations of fish, accumulations of invertebrates, etc.).

3. Insignificant range, due to the low signal to noise ratio (C / P), especially in conditions of increased sea noise (due to sea waves, etc.) at the output of the receiving part of the device.

4. Low reliability of recognition of a marine object.

The closest in technical essence to the claimed method relates to the method selected as the prototype method, the formation of directional radiation of low-frequency signals, which consists in the formation, amplification and emission into the aqueous medium of two high-frequency pump signals at frequencies ω ₁ and ω ₂ close to the resonant frequency biological sound scatterers ω _s , dominating in the region of interaction of RF pump signals at a given time of the day in a specific geographical region of the World Ocean, generation of low-frequency waves of a difference frequency in an aqueous medium Ω ₁ = ω ₁ -ω ₂ , locating with the help of the researched one, receiving the reflected wave of the difference frequency Ω ' ₁ , recognizing the studied object and determining its spatial coordinates [4].

The disadvantages of this method include:

1. The low efficiency of the method in the absence of biological scatterers of sound (their low concentration) in the region of interaction of the RF pump waves.

2. Low noise immunity of the method due to the non-directional (weakly directional) reception of the reflected signals.

3. The complexity of the detection and direction finding of a small-sized (with low reflectivity) marine object.

4. Low reliability of recognition of marine objects.

The problem that is solved by the invention is to develop a method that is free from the above disadvantages.

The technical result of the proposed method is an effective search, recognition and determination of the spatial coordinates of unmarked (poaching) fishing gear located on the ground and in the bottom sediment layer, in the interest of ensuring the rational use of marine biological resources.

This goal is achieved by the fact that in the known method, which consists in the formation, amplification and emission into the aquatic environment of the RF pump signals at frequencies ω ₁ and ω ₂ close to the resonant frequency of sound scatterers that dominate in the interaction region of the RF pump signals at frequencies ω ₁ and ω ₂ , using the first emitter of RF signals located in the lower part of the ship’s hull, generating a difference frequency wave Ω ₁ = ω ₁ -ω ₂ in the aquatic environment, locating the object under study with it, receiving a reflected difference frequency wave Ω ' ₁ , p recognition of the studied object and determination of its spatial coordinates, unmarked fishing gears are used as the studied object; RF pump signals at frequencies ω ₁ and ω ₂ are close to the resonant frequency of air bubbles ω ₀ located in the surface water layer in the region of the location of the first radiator of RF pump signals ω ₁ and ω ₂ ; the difference frequency wave Ω ₁ is relatively broadband; In addition, the formation, amplification and emission of the RF pump signals at frequencies ω ₃ and ω ₄ into the aqueous medium is carried out using the second radiator of the RF signals located in the lower part of the ship’s hull. A broadband wave of difference frequency Ω ₂ = ω ₃ -ω is generated in the aqueous medium ₄ , with the help of which the entire water column is located, the reflected waves of the difference frequency Ω ′ _{2 are} received, the acoustic characteristics of the sound diffusers and their spatial position in the entire water column are determined; additionally formed, amplified and continuously radiated into the aqueous medium using the third radiator of RF signals located in the lower part of the ship’s hull, the RF pump signal at a frequency ω n ₁ close to the subharmonic of the resonant frequency of air bubbles ω ₀ located in the surface water layer in the region the location of the third emitter of RF signals; In addition, the formation, amplification and emission of the RF pump signals at frequencies ω ₅ and ω ₆ into the aqueous medium is carried out with the help of the fourth radiator of the RF signals located in the lower part of the underwater vehicle towed at a predetermined depth, a wave is generated in the aqueous medium relative to the narrow-band difference frequency Ω ₃ = ω ₅ -ω ₆ , it is used to locate unmarked fishing gears, a reflected wave of the difference frequency Ω ' _{3 is} received, unmarked fishing gears and more their spatial coordinates are accurately determined; additionally generated, amplified and continuously radiated into the water environment using the fifth emitter of RF signals located in the lower part of the towed underwater vehicle, the RF pump signal at a frequency of ω _H2 close to the resonant frequency of sound diffusers ω _s that dominate the horizon of towed underwater vehicle in the area the location of the fifth emitter of RF signals; reception of reflected signals at difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ , as well as noise emissions Ω _b MBO located in unmarked fishing gear, is carried out using a broadband receiver located at the bottom of the towed underwater vehicle; in addition, in the aqueous medium, a nonlinear interaction of the backward-scattered RF pump waves ω ' _n1 and ω' _n2 with the reflected waves at the difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ , as well as the noise emission Ω _b MBO, occurs waves at combination frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₂ , ω ' _n1 ± Ω' ₃ , ω ' _n1 ± Ω _b , ω' _n2 ± Ω ' ₁ , ω' _n2 ± Ω ' ₂ , ω ' _n2 ± Ω' ₃ and ω ' _n2 ± Ω _b, which are received using the first RF receiver located at the bottom of the hull and using the second RF receiver located at the bottom of the towed watercraft, after demodulation, the signals at the difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ are distinguished, as well as noise emission Ω _b MBO; additionally used information on the current coordinates of the vessel, obtained using the satellite navigation system; additionally, a computer is used to process signals at frequencies Ω ' ₁ , Ω' ₂ , Ω ' ₃ , Ω _b , ω' _n1 ± Ω ' ₁ , ω' _n1 ± Ω ' ₂ , ω' _n1 ± Ω ' ₃ , ω' _n1 ± Ω _b , ω ' _n2 ± Ω' ₁ , ω ' _n2 ± Ω' ₂ , ω ' _n2 ± Ω' ₃ and ω ' _n2 ± Ω _b , as well as for acoustic spectroscopy of sound diffusers throughout the water column, recognition and assessment spatial coordinates of unmarked fishing gear.

Improving the efficiency of the search for unmarked fishing gear is achieved due to the fact that:

1. Optimized (from the point of view of maximum efficiency of the interaction of acoustic waves during their propagation in the aquatic environment) the operation of all paths of parametric radiation and directional parametric reception of signals located on the vessel and in the BPA:

- preliminary carried out using the path of parametric radiation of broadband signals, acoustic spectroscopy of sound diffusers, dominant in the entire water column;

- the parameters of the pump signals for the paths of parametric radiation and directional parametric reception of signals are selected based on the obtained data on the acoustic spectroscopy of sound diffusers (based on the maximum nonlinearity of the aqueous medium at the resonant frequencies of sound diffusers), which leads to an increase in the efficiency of use of these paths in general.

2. Ship's paths of parametric radiation of relatively relatively wideband signals, continuous radiation of an intense RF pump signal and directional parametric reception of broadband signals are used and for examining a large bottom area, but with relatively low spatial resolution.

3. Information from paths of parametric radiation, directional parametric reception and linear reception of signals located on the ship and in the control room is integrated and processed on a computer.

Improving the efficiency (reliability) of recognition of unmarked fishing gear is achieved due to the fact that:

1. Used BPA with paths of parametric radiation relative to narrowband and less intense signals, continuous radiation of a less intense RF pump signal, highly directional parametric reception of broadband signals and linear reception of broadband signals. At the same time, the BPA is towed at a given depth and course, away from the vessel, to ensure high noise immunity of the signal paths (parametric and linear), a more detailed examination of the bottom and sediment layer, including with unmarked fishing gear located on the ground.

2. Information from paths of parametric radiation, directional parametric reception and linear reception of signals located on the ship and in the control room is integrated and processed on a computer.

Improving the efficiency (accuracy) of determining the spatial coordinates of unmarked is achieved due to the fact that:

1. Information is used on the spatial position of the vessel, BPA and, ultimately, the unmarked fishing gear from the ship’s high-precision navigation satellite system.

2. Information from paths of parametric radiation, directional parametric reception and linear reception of signals located on the ship and in the control room is integrated and processed on a computer.

Distinctive features of the prototype features of the proposed method:

1. Unmarked fishing gear located on the ground and in the bottom sediment layer is used as the object under study.

2. The RF pump signals at frequencies ω ₁ and ω ₂ are close to the resonant frequency of air bubbles ω ₀ located in the surface water layer in the region of the location of the first radiator of the RF pump signals.

3. The difference frequency wave Ω ₁ is relatively broadband.

4. Additionally, the formation, amplification, and radiation of the RF pump signals at frequencies ω ₃ and ω ₄ into the aqueous medium is carried out using a second RF emitter located in the lower part of the ship’s hull; a broadband wave of difference frequency Ω ₂ = ω ₃ - ω ₄ , with the help of which the entire water column is located, reflected waves of the difference frequency Ω ' _{2 are} received, the acoustic characteristics of the sound diffusers and their spatial position in the entire water column are determined.

5. Additionally, an RF pump signal at a frequency ω _H1 close to the subharmonic of the resonant frequency of air bubbles ω ₀ located in the near-surface water layer in the area of location is formed, amplified, and continuously radiated into the water using the third RF emitter located in the lower part of the ship’s hull third RF emitter.

6. Additionally, the formation, amplification and emission of the RF pump signals at frequencies ω ₅ and ω ₆ into the aqueous medium is carried out using the fourth RF emitter located in the lower part of the underwater vehicle towed at a predetermined depth using a cable-rope, underwater generation waves with respect to the narrow-band difference frequency Ω ₃ = ω ₅ -ω ₆ , unlabelled fishing gears are located with its help, the reflected wave of the difference frequency Ω ' _{3 is} received, unmarked fishing gears are more accurately recognized and more accurately their spatial coordinates are determined.

7. Additionally, the RF pump signal is generated, amplified and continuously radiated into the aquatic environment using the fifth RF emitter located at the bottom of the towed underwater vehicle at a frequency ω _H2 close to the resonant frequency of sound scatterers ω _s that dominate the towed underwater vehicle in the area of the fifth RF emitter.

8. Reception of reflected signals at the difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ , as well as noise emissions Ω _b MBO located in unmarked fishing gear, is carried out using a broadband receiver located at the bottom of the towed underwater vehicle.

9. In addition, a nonlinear interaction of the backward-scattered RF pump waves ω ' _n1 and ω' _H2 with the reflected waves at the difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ , as well as the noise emission Ω _b MBO, occurs in an aqueous medium RF waves are generated at the combination frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₂ , ω ' _n1 ± Ω' ₃ , ω ' _n1 ± Ω _b , ω' _n2 ± Ω ' ₁ , ω' _n2 ± Ω ' ₂ , ω' _n2 ± Ω ' ₃ and ω' _n2 ± Ω _b, which are received using the first RF receiver located in the lower part of the ship's hull and using the second RF receiver located in the lower part of the towed underwater vehicle, after demodulation, the signals at the difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ are distinguished, as well as noise emission Ω _b MBO.

10. Additionally, information on the current coordinates of the vessel obtained using the satellite navigation system is used.

11. Additionally, a computer is used to process signals at frequencies Ω ' ₁ , Ω' ₂ , Ω ' ₃ , ω' _н1 ± Ω ' ₁ , ω' _н1 ± Ω ' ₂ , ω' _н1 ± Ω ' ₃ , ω' _н1 ± Ω _b , ω ' _n2 ± Ω' ₁ , ω ' _n2 ± Ω' ₂ , ω ' _n2 ± Ω' ₃ and ω ' _n2 ± Ω _b , as well as for acoustic spectroscopy of sound diffusers throughout the water column, recognition and assessment of spatial coordinates of unmarked fishing gear.

The presence of distinctive features from the prototype features allows us to conclude that the proposed method meets the criterion of "novelty."

An analysis of the known technical solutions in order to detect the indicated distinctive features in them showed the following.

Signs 1 and 10 are known in industrial fisheries, and sign 8 is known in sonar.

Symptoms 2-9 and 11 are new. At the same time, it is known to use features 2-5, 7 in nonlinear sonar to increase the efficiency of using parametric emitting and parametric receiving antennas. The use of BPA is also known for the study of marine sediments in marine geophysics and the search for marine objects located on the ground.

Thus, the presence of new features, together with the known ones, ensures that the proposed solution has a new property that does not coincide with the properties of the known technical solutions - to provide an effective search, reliable recognition and accurate determination of the spatial coordinates of unmarked (poaching) fishing gear located on the ground and in the bottom sediment layer, in the interest of ensuring the rational use of marine biological resources.

In this case, we have a new set of features and their new relationship, moreover, it is not a simple combination of new features already known in hydroacoustics (including nonlinear hydroacoustics), industrial fisheries, marine geophysics and navigation, namely, operations in the proposed sequence and leads to a qualitatively new effect.

This circumstance allows us to conclude that the developed method meets the criterion of "significant differences".

Figure 1 presents a functional diagram of the implementation of the developed method for the search for unmarked (poaching) fishing gear located on the ground and in the bottom layer of sediment.

Figure 2, 3 and 4 presents the structural diagrams of a device that implements the developed method of highly directional radiation and reception of broadband sonar signals.

The device comprises a vessel (1) towed by a cable-rope (2) an underwater vehicle (3) and an unmarked fishing gear (4) located on the ground and in the bottom sediment layer. On the ship (1) there is a satellite navigation system (5), a computer (6), as well as the paths: parametric radiation of intense relatively broadband signals (7); parametric radiation of broadband signals (8); continuous radiation of an intense RF pump signal (9); directional parametric reception of broadband signals (10). The towed underwater vehicle (3) contains the following paths: parametric radiation relative to narrowband and less intense signals (11); continuous emission of a less intense RF pump signal (12); highly directional parametric reception of broadband signals (13) and linear reception of broadband signals (14).

In this case, on the vessel (1), the path of parametric emission of relatively relatively broadband signals (7) contains electrically connected pump signal generation unit (15) at frequencies ω ₁ and ω ₂ , a first power amplifier (16) and a first radiator (17) of RF signals pumping at frequencies ω ₁ and ω ₂ close to the resonant frequency of air bubbles ω ₀ located in the surface water layer in the region of the location of the first radiator of the RF pump signals (17); the path of parametric radiation of broadband signals (8) contains a series-electrically connected pump signal generation unit (18) at frequencies ω ₃ and ω ₄ , a second power amplifier (19) and a second emitter (20) of RF pump signals at frequencies ω ₃ and ω ₄ ; the continuous radiation path of the intense RF pump signal (9) contains a series-electrically connected signal generation unit (21) at a pump frequency ω _n1 , a third power amplifier (22) and a third radiator (23) of an RF pump signal at a frequency ω _n1 close to the resonance subharmonic the frequency of air bubbles ω ₀ located in the surface water layer in the region of the location of the third radiator of the RF pump signal (23); the path (10) of the directional parametric reception of broadband signals at frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₂ , ω ' _n1 ± Ω' ₃ and ω ' _n1 ± Ω _b contains the first RF receiver in series (24 ) located in the lower part of the ship's hull, filter blocks (25), (26) and (27), respectively, for filtering signals at frequencies ω ' _н1 ± Ω' ₁ and ω ' _н1 ± Ω' ₃ , as well as ω ' _n1 ± Ω ' ₂ and ω' _n1 ± Ω _b and the processing units (18), (29) and (30) of the signals at frequencies ω ' _n1 ± Ω' ₁ corresponding to the filter blocks (25), (26) and (27) and ω ' _n1 ± Ω' ₃ , as well as ω ' _n1 ± Ω' ₂ and ω ' _n1 ± Ω _b .

Moreover, on a towed underwater vehicle (3), the path of parametric radiation with respect to narrowband and less intense signals (11) contains a series-electrically connected block (31) for generating high-frequency pump signals at frequencies ω ₅ and ω ₆ , a fourth power amplifier (32) and a fourth radiator (33) HF pump signals at frequencies ω ₅ and ω ₆ located in the lower part of the underwater vehicle towed at a given depth; the continuous radiation path of a less intense rf pump signal (12) contains a series-connected block (34) for generating a pump signal at a frequency of ω _n2 , a fifth power amplifier (35) and a fifth emitter (36) of a rf pump signal at a frequency of ω _n2 close to the resonant frequency sound diffusers ω _s , dominant on the horizon of the towed underwater vehicle in the area of the fifth emitter of the RF pump signal; the path of highly directional parametric reception of broadband signals (13) contains a second RF receiver (37) of signals ω ' _n2 ± Ω' ₁ , ω ' _n2 ± Ω' ₂ , ω ' _n2 ± Ω' ₃ and ω ' _n2 ± Ω _b a multi-channel block of filters (38) of high-frequency signals and a multi-channel block of signal processing of high-frequency signals (39); the linear reception path for broadband signals (14) contains a series-electrically connected broadband receiver (40) of signals at difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ , as well as noise emissions Ω _b MBO located in an unmarked fishing gear (4), multi-channel a filter unit (41) for wideband signals Ω ' ₁ , Ω' ₂ , Ω ' ₃ and Ω _b , as well as a multi-channel block (42) for processing broadband signals Ω' ₁ , Ω ' ₂ , Ω' ₃ and Ω _b .

An unmarked fishing gear (4) located on the ground and in the bottom sediment layer contains traps (44) for MBO (45) connected in series with each other using a special halyard (43). At the same time, an unmarked fishing gear is held at the bottom with the help of two anchors (46) located at both its edges.

The method is implemented as follows (Fig.1, 2, 3 and 4). A vessel (1) searching for an unmarked fishing gear (4) is towed by an underwater vehicle (3) using a cable (2). On the ship (1) there is a satellite navigation system (5), which allows to determine the coordinates of the ship in space with high accuracy, as well as a computer (6), which provides control of the operation of all paths on the ship (1) and the towed underwater vehicle (3). In addition, the computer (6) ultimately solves the problems of efficient search, recognition and determination of the spatial coordinates of unmarked fishing gear (4) located on the ground and in the bottom sediment layer. Moreover, in the traps (44) interconnected by means of a special halyard (43), there are MBO (45), which emit broadband signals Ω _b during their life activity.

In the path of parametric radiation of broadband signals (8) using a series-electrically connected pump signal generation unit (18) at frequencies ω ₃ and ω ₄ , a second power amplifier (19) and a second emitter (20) of RF pump signals, the amplification is generated to the required level and radiation into the aqueous medium of the RF pump signal at frequencies ω ₃ and ω ₄ . In the aquatic environment, a broadband wave of difference frequency Ω ₂ = ω ₃ -ω ₄ is generated, with the help of which the entire water column is located from the surface to the bottom.

In the path of continuous emission of an intense RF pump signal (9), using a series-electrically connected signal generation unit (21) at a pump frequency ω _N1 , a third power amplifier (22) and a third radiator (23) of the RF pump signal, the amplification is generated to the required level and radiation into the aqueous medium of the RF pump signal at a frequency ω _n1 close to the subharmonic of the resonant frequency of air bubbles ω ₀ located in the surface water layer in the region of the location of the third radiator of the RF pump signal and (23). In an aqueous medium, a nonlinear interaction of the backward-scattered RF pump wave ω ' _{n1 occurs} with the broadband wave Ω' ₂ reflected from the inhomogeneities (sound diffusers located throughout the water column) of the aqueous medium. In this case, an RF wave is generated at the combination frequency ω ' _n1 ± Ω' ₂ , which is received using the first RF receiver (24) located in the lower part of the ship's hull (1), tract (10) for parametric reception of broadband signals. Next, the RF signal at the combination frequency ω ' _n1 ± Ω' _{2 is} fed to the input of the filter unit (26), where RF interference is suppressed. From the output of the filter unit (26), the RF signal at the combination frequency ω ' _n1 ± Ω' _{2 is} fed to the corresponding signal processing unit (29), in which the useful broadband signal Ω ' _{2 is extracted} from the RF signal at the combination frequency ω' _n1 ± Ω ' ₂ detection method. From the output of the processing unit (29), the broadband signal Ω ' _{2 is} fed to the input of the computer, where it is compared with the reference signal Ω ₂ and a decision is made on spatial (horizon, length, etc.) and acoustic (resonant frequency, layer strength, etc. ) characteristics of air defense systems located in the entire water column (acoustic spectroscopy of sound diffusers is carried out). For example (Fig. 1), the vertical length of the near surface ZRS is h ₁ (m), and the resonant size of the dominant air bubbles in the layer is l ₁ , the vertical length of the deep biological SAM is h ₂ (m), and the resonant size of air bubbles dominating in the layer is l ₂ , the vertical length of the near-bottom biological ZRS is h ₃ (m), and the resonant size of the air bubbles dominating in the layer is l ₃ . Based on the obtained results on acoustic spectroscopy of sound diffusers, the towing horizon of the underwater vehicle (3) is set equal to the upper boundary of the layer of deep biological air defense systems or the upper boundary of the layer of bottom biological air defense systems.

Moreover, in the path of parametric radiation with respect to broadband signals (7) using a series-electrically connected unit for generating RF pump signals (15) at frequencies ω ₁ and ω ₂ , the first power amplifier (16) and the first emitter (17) of the RF pump signals at frequencies ω ₁ and ω ₂ is the formation, amplification to the required level and the emission of the RF pump signal at frequencies ω ₁ and ω ₂ close to the resonant frequency ω _{0 of} air bubbles (in Fig. 1 with size l ₁ ) located in the near-surface water layer in the region situated I first radiator (17) RF signals pump ω ₁ and ω _2. A relatively broadband wave of difference frequency Ω ₁ = ω ₁ -ω ₂ is generated in the aquatic environment, with the help of which the bottom is located over a large area, including an unmarked fishing gear located on the ground and in the bottom layer of sediments at different angles to the direction of travel vessel (1). In the path (11) of parametric radiation with respect to narrowband and less intense signals, using the series-electrically connected unit (31) for generating the RF pump signals at frequencies ω ₅ and ω ₆ , the fourth power amplifier (32) and the fourth emitter (33) of the RF pump signals frequencies ω ₅ and ω ₆ is the formation, amplification to the required level and radiation into the aqueous medium of the RF pump signals at frequencies ω ₅ and ω ₆ . In the aquatic environment, a wave is generated with respect to the narrow-band difference frequency Ω ₃ = ω ₅ -ω ₆ , it is used to locate an unmarked fishing gear (at a shorter range, in narrow solid angle, at the optimal course of movement of the towed underwater vehicle, etc.), the reflected wave of the difference frequency Ω ' _{3 is} received and more reliably (in the final case) unmarked fishing gears are recognized and their coordinates are more accurately determined.

In the continuous emission path of a less intense RF pump signal (12), using a series-electrically connected unit (34) for generating a pump signal at a frequency ω _H2 , a fifth power amplifier (35) and a fifth emitter (36) of the RF pump signal, the amplification is generated to the required the level and radiation of the RF pump signal at a frequency ω _n2 close to the resonant frequency ω _s of the sound diffusers (in Fig. 1 of size l ₂ ), which dominate the horizon of the towed underwater vehicle (3) in the area of the fifth radiation Teacher (36) HF pump signal.

In an aqueous medium, a nonlinear interaction of backward-scattered RF pump waves ω ' _n1 and ω' _{n2 occurs} with reflected waves at difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ , as well as noise emission Ω _b MBO, and RF waves are generated at the combination frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₂ , ω ' _n1 ± Ω' ₃ , ω ' _n1 ± Ω _b and ω' _n2 ± Ω ' ₁ , ω' _n2 ± Ω ' ₂ , ω ' _n2 ± Ω' ₃ , ω ' _n2 ± Ω _b, which are respectively received using the first RF receiver (24) of the path (10) for parametric reception of broadband signals and using the second RF receiver (37) of the path parametric reception of broadband signals (13). Further (by analogy with the RF signal at the Raman frequency ω ' _n1 ± Ω' ₂ ), the RF signals at the Raman frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₃ , and ω ' _n1 ± Ω _b are fed to the inputs of the corresponding filter blocks (25) and (27), where RF interference is suppressed. From the output of the filter unit (26), the RF signals at the combination frequencies ω ' _n1 ± Ω' ₁ , ω ' _n1 ± Ω' ₃ , and ω ' _n1 ± Ω _b are fed to the inputs of the corresponding signal processing units (28) and (30), in which the useful broadband signals Ω ' ₁ , Ω' ₂ and Ω ' _{b are extracted} from the RF signals at the combination frequencies ω' _n1 ± Ω ' ₁ , ω' _n1 ± Ω ' ₃ and ω' _n1 ± Ω _b by the detection method. From the outputs of the signal processing units (28) and (30), the broadband signals Ω ′ ₁ , Ω ′ ₂ and Ω ′ _b are fed to the input of the computer. At the same time, the signals at the high-frequency combination frequencies ω ' _n2 ± Ω' ₁ , ω ' _n2 ± Ω' ₂ , ω ' _n2 ± Ω' ₃ , ω ' _n2 ± Ω _b come from the output of the second high-frequency receiver (37) to the input of the multi-channel filter block (38), where RF interference is suppressed for each channel (each RF combination frequency). From the output of the filter unit (26), the RF signals at the combination frequencies ω ' _n2 ± Ω' ₁ , ω ' _n2 ± Ω' ₂ , ω ' _n2 ± Ω' ₃ , ω ' _n2 ± Ω _b are fed to the corresponding inputs of the multi-channel signal processing unit (39), in which the broadband signals Ω ' ₁ , Ω' ₂ , Ω ' ₃ , and Ω _{b are extracted} from the HF signals at the combination frequencies ω' _n2 ± Ω ' ₁ , ω' _n2 ± Ω ' ₂ , ω' _n2 ± Ω ' ₃ , ω' _n2 ± Ω _b by the detection method. From the output of the multi-channel signal processing unit (39), useful broadband signals Ω ′ ₁ , Ω ′ ₃ and Ω _b are fed to the input of the computer.

At the same time, in the linear reception path of broadband signals (14) using a series-electrically connected broadband receiver (40) located in the lower part of the towed underwater vehicle (3), a multi-channel filter block (41) and a multi-channel block (42) for processing broadband signals reception, filtering and processing of reflected signals at difference frequencies Ω ' ₁ , Ω' ₂ and Ω ' ₃ , as well as noise emissions Ω _b MBO located in an unmarked fishing gear (4). In a computer, all useful signals Ω ' ₁ , Ω' ₃ and Ω _{b are} compared with the reference signals Ω ₁ , Ω ₃ and Ω _b and the final decision is made on the detection, identification and determination of the spatial coordinates of the unmarked (bacon) fishing gear located on the ground and in the bottom sediment layer.

Figure 5 presents typical, experimentally obtained, the dependence of the nonlinearity parameter ε of the aquatic environment (vertical axis) on the signal frequency (f, kHz) and the horizontal (× 2 m) location of the emitter-receiver acoustic system for the south (figa) and northern (figb) geographical regions [5]. As can be seen from Fig. 5, there is a pronounced dependence of the nonlinearity parameter on frequency (in the range of ~ 7 to ~ 52 kHz) and depth (in the range of ~ 22 to ~ 60 m) for the surface layer of air bubbles formed in water during wind waves (in Fig. 1, layer h ₁ with characteristic bubble sizes l ₁ ). In this case (Fig. 5a), the value of the nonlinearity parameter at a frequency of ~ 32 kHz reaches ~ 300, which is 2 orders of magnitude higher than for the nonlinearity parameter of a homogeneous (free of air bubbles) aqueous medium [6].

On figa, b presents echograms of signals with a fixed frequency of 25.5 kHz, recorded at the output of the ship's navigation and fish finder NEL-5P during testing of the developed method. As can be seen from figa, b, additional (to the near-surface bubble layer) inhomogeneity (non-linearity) can be introduced by biological air defense systems, which rise at night from depth to the upper layers of the sea. On figv, d presents the vertical distribution of the speed of sound (C) in depth (H) and the oscillogram of the probing signal of the sonar NEL-5P, respectively, in the depth range from 10 to 200 m in one of the areas of the Sea of Okhotsk during marine tests. As can be seen from figv in the surface layer of the sea recorded a sharp drop in the speed of sound (~ up to 25 m / s) due to the presence of air bubbles in the layer. The presence of sound diffusers in the near-surface layer of the sea during typical wind waves is confirmed by the waveforms of the signals from the NEL-5R sonic depth finder shown in Figs. 6g, 7b, and d. ZRS (figure 1 layer h ₃ with characteristic sizes of bubbles l ₃ ).

On figa, c and on figb, d shows the vertical distribution of the speed of sound (C) in depth (H) and the oscillogram of the probe signal of the sonar NEL-5P, respectively, in the depth range from 10 to 200 m in some areas of the Sea of Okhotsk during experimental research. As can be seen from figa, in the near-surface layer of the sea, the difference in sound velocity is recorded (~ up to 20 m / s), due to the presence of air bubbles in the layer, and in the deep air defense system a sharper difference in sound speed is recorded (~ up to 30 m / s) due to the presence of biological ZRS in the layer. The presence of sound diffusers in the near-surface and deep layers of the sea is also confirmed by the waveforms of the signals from the NEL-5R echo sounder shown in Fig. 7b, d. Moreover, the presence of three deep SAM systems due to the presence of biological ZRS (figure 1 layer h ₂ with characteristic sizes of bubbles l ₂ ).

On Fig illustrates an example of the operational recognition of MBO, located in an unmarked (poaching) fishing gear, according to the spectrum of combination frequency signals recorded at the output of the RF receiver located on the ship's hull. At the same time on figb presents the spectrogram of the scattered RF pump wave ω ' _n1 in the absence of noise MBO; on figv, d presents spectrograms of the RF signals of the Raman frequencies ω ' _n1 ± Ω _b recorded at the output of the RF receiver in the presence of MBO noise with a predominance of RF components in the spectrum of their noise emission (Fig.8c) and in the presence of MBO noise with a predominance of LF components in the spectrum of their noise emission. On figa illustrates the spectrogram of acoustic noise in the frequency range from units of Hz to 20 kHz in the absence of radiation of the RF pump signal at a frequency ω _n1 . As can be seen from figv, in the case of the dominance in the noise emission spectrum of MBO Ω _b RF components in the region of the RF pump signal ω ' _n1 RF combinational frequencies are recorded as a “pedestal”. In the case of the predominance in the noise emission spectrum of MBO Ω _b LF components in the region of the HF pump signal ω ' _n1 HF Raman frequencies are recorded in the form of a “bell” (Fig. 8g). At the same time (figv, d) there is a decrease (~ by 6-8 dB) of the level of the scattered RF pump signal ω ' _n1 compared to its similar parameter in the absence of a noisy object (fig.8b).

Figure 9, for example, presents sonograms of the noise of the crab-stringer opilio (Figa) and Kamchatka crab (Fig.9b), recorded at the output of the signal processing unit when implementing the developed method for searching for unmarked fishing gear. As can be seen from figa, in the frequency range from units of Hz to 3 kHz, three conditional frequency sub-ranges (400-600 Hz, 800-1200 Hz and 2.2-3 kHz) with the characteristic sounds of the opilio shear crab are distinctly recorded. While the sounds of the Kamchatka crab (significantly different in size and body structure) are lower frequency and the main energy of their noise is concentrated in the frequency range from 200 to 700 Hz (Fig. 9b).

Thus, MBO (invertebrates, fish, etc.) in unmarked (poaching) fishing gears can be detected and identified by the spectra of signals recorded at the input and output of the path of parametric reception of broadband signals (located on the ship and (or) in the BPA), as well as at the output of the linear path for receiving broadband signals located in the BPA.

An example implementation of the method.

In 1998, an unmarked order of traps (100 pcs.) With Kamchatka crab was hoisted aboard in the fishing area. For a more accurate estimate of the number of crabs, its species and biological state, 3 traps were taken (at the beginning, middle, and end of the order) and the typical (by group) amount of crab in them was averaged. Due to the limited time, non-commercial males (juveniles) and females were brought into one group. It turned out that in one “typical” trap there are 58 individuals of the crab, of which: ~ 25 individuals (~ 43%) are the commercial individuals of the crab, and the remaining 33 individuals. (~ 57%) - juveniles and females. At the same time, 11 pcs. (~ 20%) - dead crab (exclusively juveniles and females), ~ 30% (18 pcs.) - damaged crab (of which 2 pcs. Are commercial individuals, and 16 pcs. Are juveniles and females) and ~ 50% ( 29 pcs.) - whole individuals of the crab (23 of them - commercial individuals, and 6 pcs. - juveniles and females). In other words, 22 pcs. (~ 38%) of the total biomass was killed and damaged females and juvenile crab, the catch of which is strictly prohibited by the rules of fishing. Thus, in one lost order (out of 100 traps) 290 pcs. (~ 50%) crabs were substandard and accounted for current environmental losses, and the total loss of the crab was 580 individuals per unmarked crab order.

By analogy, we estimate the damage caused to the Opilio crab population by one unlabelled (poaching) crab order. In 1999, in the fishing area, 2 unmarked trap orders were taken aboard. It turned out that in one such “averaged” trap there are ~ 98 individuals of this crab, of which: -44 pcs. (~ 45%) are commercial individuals, and the rest are ~ 54 pcs. (~ 55%) - juveniles and females. At the same time, ~ 14 pcs. (~ 14%) - dead crab (~ 2 pcs. - commercial individuals, ~ 12 pcs. - juveniles and females), ~ 28 pcs. (~ 28%) - damaged crab (of which ~ 4 pcs. Are commercial individuals, and ~ 24 pcs. Are juveniles and females) and ~ 56 pcs. (~ 57%) - whole individuals of the crab (of which 38 pcs. Are commercial individuals, and 18 pcs. Are juveniles and females). Thus, in one lost order (~ 100 traps) 420 pcs. (~ 42%) crabs were substandard and accounted for current environmental losses, while the total loss of the opilio shear crab was 980 individuals per unmarked (poaching) crab order.

The above figures, of course, are approximate. However, they to some extent allow us to estimate the scale of economic and environmental losses that occur during the crab fishery in the Russian Federation, including the use of unmarked (poaching) fishing gear.

Literature

1. Mitko VB, Evtyutov A.P., Gushchin S.E. Hydroacoustic communications and surveillance. - L .: Shipbuilding, 1982, p.119.

2. Shishkova E.V. Physical fundamentals of field sonar. - M.: Food Industry, 1977, p.213.

3. Novikov B.K., Rudenko S.V., Timoshenko V.N. Nonlinear sonar. - L .: Shipbuilding, 1978, p. 7-12.

4. The method of forming directional radiation of low-frequency signals. - RF patent No. 2096807, priority 01.02.94, application No. 94003782.

5. Bulanov V.A. Acoustics of microinhomogeneous liquids and methods of acoustic spectroscopy // Dissertation of the doctor of physical and mathematical sciences - Vladivostok: IPMT FEB RAS, 1996, p. 358-391.

6. Novikov B.K., Rudenko S.V., Timoshenko V.N. Nonlinear hydroacoustics, - L .: Shipbuilding, 1978, p. 7-12.

7. Bakharev S.A., Bondar L.F., Gorkavenko V.V. et al. Studies of the effect of hydrophysical parameters of the marine environment on the acoustic field in the offshore zone. - Report on the scientific research work “Aquatoria”, the State Committee for Fisheries. - Vladivostok: Dalrybvtuz, 1999, 151 p.

Claims (1)

A method of searching for unmarked (poaching) fishing gear located on the ground and in the bottom layer of sediments, which consists in the formation, amplification and emission of high-frequency pump signals at frequencies ω ₁ and ω ₂ close to the resonant frequency of sound diffusers that dominate in the interaction region high pump signals at frequencies ω ₁ and ω _2, by a first high-frequency signal transmitter, located at the bottom of the hull, generating in an aqueous medium wave frequency difference ω ₁ = ω ₁ -ω _2, lotsiruetsja Vania with the help of an object, the reception of the reflected wave at the difference frequency Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{one}}$ , recognition of the investigated object and determination of its spatial coordinates, characterized in that unmarked fishing gears are used as the studied object; high-frequency pump signals at frequencies ω ₁ and ω ₂ are close to the resonant frequency of air bubbles ω ₀ located in the surface water layer in the region of the first emitter of high-frequency pump signals ω ₁ and ω ₂ ; the difference frequency wave Ω ₁ is relatively broadband; additionally, the formation, amplification and emission of high-frequency pump signals at frequencies ω ₃ and ω ₄ into the aqueous medium is carried out using a second high-frequency signal emitter located in the lower part of the ship’s hull; a wide-band differential-frequency wave is generated in the aqueous medium Ω ₂ = ω ₃ -ω ₄ , with which the entire water column is located, the reflected waves of the difference frequency Ω are received $\genfrac{}{}{0ex}{}{\text{''}}{\text{2}}$ , the acoustic characteristics of sound diffusers and their spatial position in the entire water column are determined; in addition, a high-frequency pump signal at a frequency ω _n1 close to the subharmonic of the resonant frequency of air bubbles ω ₀ located in the surface layer of water in the area of location is additionally formed, amplified, and continuously radiated into the aqueous medium using the third emitter of high-frequency signals third emitter of high-frequency signals; additionally, the high-frequency pump signals are generated, amplified and emitted into the aqueous medium at frequencies ω ₅ and ω ₆ , using the fourth high-frequency signal emitter located in the lower part of the underwater vehicle towed at a predetermined depth, a wave is generated in the aquatic environment relatively narrow-band difference frequency Ω ₃ = ω ₅ -ω ₆ , it is used to locate unmarked fishing gear, a reflected wave of difference frequency Ω is received $\genfrac{}{}{0ex}{}{\text{''}}{\text{3}}$ , unmarked fishing gears are more accurately recognized and their spatial coordinates are more accurately determined; additionally formed, amplified and continuously radiated into the aquatic environment using the fifth emitter of high-frequency signals located in the lower part of the towed underwater vehicle, a high-frequency pump signal at a frequency of ω _H2 close to the resonant frequency of sound diffusers ω _s that dominate the horizon of the towed underwater vehicle in the area of the fifth emitter of high-frequency signals; reception of reflected signals at difference frequencies Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{one}}$ , Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{2}}$ and Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{3}}$ , as well as noise emissions Ω _{b of} marine biological objects found in unmarked fishing gear, is carried out using a broadband receiver located at the bottom of the towed underwater vehicle; additionally, in a water medium, a nonlinear interaction of high-frequency pump waves ω ' _n1 and ω' _n2 scattered in the opposite direction _occurs with reflected waves at difference frequencies Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{one}}$ , Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{2}}$ and Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{3}}$ , as well as noise emission Ω _{b of} marine biological objects, in this case high-frequency waves are generated at combination frequencies in ω ' _н1 ± Ω' ₁ , ω ' _н1 ± Ω' ₂ , ω ' _н1 ± Ω' ₃ , ω ' _н1 ± Ω _b , ω ' _n2 ± Ω' ₁ , ω ' _n2 ± Ω' ₂ , ω ' _n2 ± Ω' ₃ and ω ' _n2 ± Ω _b , which are received using the first high-frequency receiver located in the lower part of the ship's hull and using the second high-frequency the receiver located in the lower part of the towed underwater vehicle, after demodulation, the signals at the difference frequencies Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{one}}$ , Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{2}}$ and Ω $\genfrac{}{}{0ex}{}{\text{''}}{\text{3}}$ , as well as noise emission Ω _b , marine biological objects; additionally used information on the current coordinates of the vessel, obtained using the satellite navigation system; additionally, an electronic computer is used to process signals at frequencies Ω ' ₁ , Ω' ₂ , Ω ' ₃ , Ω _b , ω' _n1 ± Ω ' ₁ , ω' _n1 ± Ω ' ₂ , ω' _n1 ± Ω ' ₃ , ω ' _n1 ± Ω _b , ω' _n2 ± Ω ' ₁ , ω' _n2 ± Ω ' ₂ , ω' _n2 ± Ω ' ₃ and ω' _n2 ± Ω _b , as well as for acoustic spectroscopy of sound diffusers throughout the water column, recognition and estimation of spatial coordinates of unmarked fishing gear.

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