RU2484492C1 - Hydroacoustic system for measuring coordinates of sound source in shallow sea - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: hydroacoustic measurement system has N composite acoustic receivers, a telemetering unit having voltage dividers, an analogue-to-digital converting circuit, a single electronic multiplexing circuit, a modulator and an optical emitter, a system for collecting, processing and transmitting information and a device for accessing digital data networks. An orthogonal bottom base is formed in the hydroacoustic measurement system by three composite acoustic receivers P1, P2 and P3. Additional composite acoustic receivers and the receiver P1 form a bottom vertically oriented equidistant antenna. The system for collecting, processing and displaying information further includes an (N+1)-channel unit for calculating the vertical component of the intensity vector, a unit for determining the maximum of the vertical component of the intensity vector, an (N+3)-channel unit for calculating horizontal components of the intensity vector, an (N+1)-channel unit for calculating the azimuthal angle, a unit for calculating the averaged azimuthal angle, a unit for calculating the azimuthal angle for composite acoustic receivers P2 and P3 and a unit for determining coordinates of the sound source.

EFFECT: longer range of the hydroacoustic system and reduced error in measuring coordinates of a sound source by increasing the aperture of its measurement system.

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Description

The invention relates to hydroacoustics and can be used to measure the coordinates of the source of sound waves in the shallow sea in passive mode using acoustic receivers mounted on the seabed, the coordinates of which and the angular position are considered known.

A device is known [Schurov V.A. Vector ocean acoustics. Vladivostok: Dalnauka, 2003. P.31.] For measuring the azimuthal angle to a sound source in passive mode, containing a sound pressure receiver installed at the bottom and a three-component receiver of the vibrational velocity vector, which together form an acoustic combined receiver, as well as local angular position sensors coordinate systems associated with the acoustic receiver relative to the geographical coordinate system. In this device, the components of the intensity vector I _x , I _y are measured in a local orthogonal coordinate system associated with an acoustic combined receiver, and the direction to the sound source is determined by the formula

$$\varphi =arctg\left(\frac{I_y}{I_x}\right)(\mathrm{one})$$

where φ is the azimuthal angle in the horizontal plane, measured from the X axis of the local coordinate system associated with the acoustic combined receiver. If necessary, the results of measurements of the angular position of the sound source in the local coordinate system are recalculated into the bearing.

Similarly, you can determine the elevation angle if the acoustic combined receiver is located in the near zone of the sound source

$$\theta =arctg\left(\frac{I_z}{I_r}\right),I_r=\sqrt{I_x^2+I_y^2}(2)$$

The disadvantage of this measuring device is the large measurement error of the azimuthal angle and bearing, due to the insufficient directivity of the acoustic combined receiver, which is dipole, and the short range associated with the insufficient noise immunity of a single acoustic combined receiver. In addition, if the combined receiver is located in the far zone of the source or if the measuring system operates in a shallow sea, then formula (2) gives a large error and cannot be used to measure the elevation angle of the sound source.

A device is known [RF Patent for Utility Model 82972, IPC, H04B 10/00], in which a multichannel digital combined hydroacoustic complex containing N acoustic combined receivers, each of which consists of a hydrophone, a three-component vector receiver and connected to amplifiers, a telemetric unit, the input of which is connected to the output of the acoustic combined receivers, including voltage dividers, analog-to-digital conversion circuit, a single circuit electronic multiplexing, a modulator and an optical emitter connected by an optical line of communication with an optical receiver, as well as a system for collecting, processing and displaying information, containing a collection unit for processing and displaying information, the input of which is connected to the output of the optical receiver, an access device to digital data transmission networks, the input of which is connected to the output of the information processing and display unit, and the radiation shaper, the input and output of which are connected to the input and output of the collection unit processing and displaying information. In this device, N acoustic combined receivers and a program module for forming the radiation pattern in real time form a hydroacoustic antenna, which has increased noise immunity and low measurement error of the azimuthal angle and bearing to the sound source compared to the analogue [1]. This device is the closest to the claimed invention.

The disadvantage of this device is the impossibility of a significant increase in the number of combined acoustic receivers and antenna aperture due to significant dispersion distortion of the acoustic signal during its propagation in the shallow sea. Due to such distortions, the phasing algorithms of the signals received by individual antenna elements, which form the basis for the functioning of the beam former, and the algorithm for determining the azimuthal angle to the sound source by formula (1) become ineffective. As a result, the range of the measuring antenna does not increase, and the measurement error of the bearing does not decrease with increasing aperture of the antenna. In addition, when the measuring complex operates in the shallow sea, the errors in determining the elevation angle and coordinates of the sound source become unacceptably large.

The present invention is based on the task of increasing the range of the complex and reducing the measurement error of the azimuthal angle, elevation angle and coordinates of the sound source by increasing the aperture of its measuring system. To achieve this goal, it is proposed to use the correlation properties of the sound field with respect to the vertical component of the intensity vector. In accordance with the results of the work [Schurov V.A., Kuleshov V.P., Tkachenko E.S. Vortices of acoustic intensity in the shallow sea // Technical Acoustics. 2010. No. 12. http://www.ejta.org ] the vertical component of the intensity vector has a pronounced periodic structure in the sound field created by the sound source in the shallow sea at distances significantly exceeding the size of the near zone r _b = H ² / λ (H is the depth of the sea, λ is the wavelength at the middle frequency of the operating frequency range). This means that the sound fields are highly correlated with respect to the vertical component of the intensity vector measured at various points spaced in space over distances significantly exceeding the size of the near zone. In addition, the maximum amplitude of the vertical component of the intensity vector exactly corresponds to the source horizon.

To accomplish this task in a sonar measuring complex containing N acoustic combined receivers, each of which consists of a hydrophone, a three-component vector receiver and amplifiers connected to them, a telemetry unit, the input of which is connected to the output of the acoustic combined receivers, including voltage dividers, analog-digital a conversion circuit, a single electronic multiplexing circuit, and an optical emitter connected by an optical communication line to an optical res by faith, a system for collecting, processing and displaying information containing a unit for collecting, processing and displaying information, the input of which is connected to the output of the optical receiver, and a device for accessing digital data networks, the input of which is connected to the output of the block for collecting, processing and transmission of information, by combined three acoustic receivers P1, P2, P3, the bottom formed orthogonal to the base, wherein the base distance L _x between detectors P1, P2 is oriented along the x axis, the base distance L _y is equal to the projection distance m waiting receivers P1, P3 on the Y-axis of the local orthogonal coordinate system, the basic distances are chosen from the condition L _x ≥H ² / λ, L _y ≥H ² / λ, a combined acoustic receiver P1 supplemented N acoustic receivers combined, forming a vertically oriented (N +1) -element equidistant antenna, in which the distance between the acoustic combined receivers is equal to the specified error in determining the vertical coordinate of the sound source Δz, and the number of acoustic combined receivers is N = H / Δz.

In addition, an (N + 1) -channel unit for calculating the vertical component of the intensity vector, the input of which is connected to the output of the unit for collecting, processing and displaying information, a unit for determining the maximum of the vertical component of the intensity vector, whose input connected to the output of the (N + 1) -channel unit for calculating the vertical components of the intensity vector, (N + 3) -channel unit for calculating the horizontal components of the intensity vector, the input of which is connected to the unit of information collection, processing and display, (N + 1) -channel calculating the azimuthal angle for the first acoustic combined receiver P1, the input of which is connected to the first output of the (N + 3) -channel calculating horizontal components of the intensity vector, the calculation unit averaged azimuthal angle for the first acoustic combined receiver P1, the first input of which is connected to the output of the (N + 1) -channel azimuthal angle calculation unit for the first acoustic combined receiver P1, and w The second input is connected to the second output of the (N + 3) -channel unit for calculating the horizontal components of the intensity vector, and the average azimuthal angle <φ ₁ > is determined by the formula

$$〈{\varphi }_{\mathrm{one}}〉={\displaystyle \sum _{n=\mathrm{one}}^{N+\mathrm{one}}{\varphi }_n\frac{I_{xn}^2+I_{yn}^2}{I^2},I^2={\displaystyle \sum _{n=\mathrm{one}}^{N+\mathrm{one}}(I_{xn}^2+I_{yn}^2)(3)}}$$

where φ _n , I _xn , I _yn is the azimuthal angle and intensity vector components related to the n-th acoustic combined receiver of a vertical (N + 1) -element antenna, and the horizon of the acoustic combined receiver corresponding to the maximum of the vertical component is taken as the source horizon intensity vector, determined in the block for determining the maximum of the vertical component of the intensity vector. Information from the output of the unit for calculating the average azimuthal angle and the unit for determining the maximum of the vertical component of the intensity vector is fed to the first input of the unit for determining the coordinates of the sound source.

In addition, the azimuthal angle calculation unit for acoustic combined receivers P2 and P3 is included in the information collection, processing and transmission system, the input of which is connected to the third output of the (N + 3) -channel unit for calculating the horizontal components of the intensity vector, the unit for determining the coordinates of the sound source the first input of which is connected to the output of the unit for determining the maximum of the vertical component of the intensity vector, the second input is connected to the output of the unit for calculating the average azimuthal angle for n of the first acoustic combined receiver P1, the third input is connected to the output of the azimuthal angle calculation unit for acoustic combined receivers P2 and P3, the horizon of the acoustic combined receiver, which corresponds to the maximum of the vertical component of the intensity vector, determined in the block for determining the maximum of the vertical component of the intensity vector, is taken as the source horizon, and the horizontal coordinates of the sound source are the coordinates of the center of gravity of the triangle, images nnogo intersection of three lines of position <φ _1> = const, φ ₂ = const, φ ₃ = const, corresponding to the three azimuthal angles <φ _1>, φ _2, φ _3. Such a triangle is called a residual triangle, and its size characterizes the error in determining the coordinates of the sound source. This error is minimized if the center of gravity of the residual triangle is taken as the true coordinates of the sound source. It is well known that the center of gravity of a triangle is the intersection point of its medians, i.e. the center of gravity is uniquely defined for any triangle.

In the proposed complex, the essential features common with the prototype are:

- N acoustic combined receivers, each of which consists of a hydrophone, a three-component vector receiver and amplifiers connected to them;

- a telemetry unit including voltage dividers, an analog-to-digital conversion circuit, a single electronic multiplexing circuit, a modulator and an optical emitter connected by an optical communication line to an optical receiver;

- a system for collecting, processing and transmitting information, comprising a unit for collecting, processing and transmitting information, and a device for accessing digital data networks.

Distinctive essential features are:

,- through three acoustic combined receivers P1, P2, P3, a bottom orthogonal base is formed in which the base distance L _x between the receivers P1, P2 is oriented along the X axis, the base distance L _y is equal to the projection of the distance between the receivers P1, P3 on the Y axis of the local orthogonal system coordinates, and the base distances are selected from the condition $$L_x\ge \raisebox{1ex}{$H^2$}\!\left/ \!\raisebox{-1ex}{$\lambda $}\right.,L_y\ge \raisebox{1ex}{$H^2$}\!\left/ \!\raisebox{-1ex}{$\lambda $}\right.$$

,

- N additional acoustic combined receivers and receiver P1 form a bottom vertically oriented equidistant antenna, in which the distance between the acoustic combined receivers is equal to the specified error in determining the vertical coordinate (horizon) of the sound source Δz, and the number of receivers is N = H / Δz,

- (N + 1) -channel unit for calculating the vertical component of the intensity vector, the input of which is connected to the output of the unit for collecting, processing and displaying information;

- a unit for determining the maximum of the vertical component of the intensity vector, the input of which is connected to the output of the (N + 1) -channel unit for calculating the vertical component of the intensity vector;

- N + 3-channel unit for calculating the horizontal components of the intensity vector, the input of which is connected to the output of the unit for collecting, processing and displaying information;

- (N + 1) -channel block for calculating the azimuthal angle, the input of which is connected to the first output of the (N + 3) -channel block for calculating the horizontal components of the intensity vector;

- a unit for calculating the average azimuthal angle, the first input of which is connected to the output of the (N + 1) -channel unit for calculating the azimuthal angle, and the second input is connected to the second output of the (N + 3) -channel unit for calculating the horizontal components of the intensity vector;

- the average azimuthal angle is determined by the formula (3)

, $$〈{\varphi }_{\mathrm{one}}〉={\displaystyle \sum _{n=\mathrm{one}}^{N+\mathrm{one}}{\varphi }_n\frac{I_{xn}^2+I_{yn}^2}{I^2},I^2={\displaystyle \sum _{n=\mathrm{one}}^{N+\mathrm{one}}(I_{xn}^2+I_{yn}^2)}}$$

,

where φ _n , I _xn , I _yn is the azimuthal angle and the components of the intensity vector related to the nth acoustic combined receiver,

- the horizon of the sound source (for the vertical coordinate) is the horizon of the acoustic combined receiver, which corresponds to the maximum of the vertical component of the intensity vector, which is determined in the unit for determining the maximum of the vertical component of the intensity vector;

- the horizontal coordinates of the sound source are the coordinates of the center of gravity of the triangle formed by the intersection of three position lines <φ ₁ > = const, φ ₂ = const, φ ₃ = const, corresponding to the three azimuthal angles <φ ₁ >, φ ₂ , φ ₃ .

Thus, it is this combination of essential features of the claimed device that allows you to create a sonar measuring complex for measuring the coordinates of the sound source, reduce the measurement error and increase the range of the complex itself when working in the shallow sea.

The novelty of the proposed device lies in the fact that it uses a bottom vertically oriented equidistant antenna as a measuring complex, in which the distance between the acoustic combined receivers is equal to the specified error in determining the vertical coordinate (horizon) of the sound source Δz, and the vertical component of the vector is used as the working signal intensity. It is this characteristic that has the greatest spatial correlation in the sound field in the shallow sea, is least affected by interference, and has a causal relationship with the source horizon.

In addition, to determine the horizontal coordinates of the sound source, an orthogonal bottom base is used, formed by three combined acoustic receivers P1, P2, P3, and redundant information about the angular position of the sound source, which minimizes the error in their determination. It is this feature that can significantly reduce the measurement error and increase the range of the entire device.

Based on the foregoing, we can conclude that the set of essential features of the claimed invention has a causal relationship with the achieved technical result.

The invention is illustrated by drawings, where figure 1 shows a bottom vertically oriented equidistant antenna and a triple of acoustic combined receivers P1, P2, P3, forming a bottom orthogonal base, i.e. the location geometry of the acoustic receivers and the sound source relative to the local coordinate system, figure 2 - three acoustic receivers P1, P2, P3 in the horizontal plane; figure 3 is a block diagram of a sonar measuring complex.

The claimed sonar system for measuring the coordinates of a sound source in a shallow sea contains an (N + 3) -element bottom antenna I, a telemetry unit II and a system III for collecting, processing and transmitting information.

The bottom antenna I contains three acoustic combined receivers P1, P2, P3, forming a bottom orthogonal base, and a vertically oriented equidistant antenna formed by N acoustic combined receivers and a receiver P1, each of which consists of a hydrophone, a three-component vector receiver and amplifiers connected to them (not shown in the drawing). The location geometry of the acoustic receivers and the sound source relative to the local coordinate system is illustrated in figure 1 and figure 2.

The telemetry unit includes: voltage dividers 1, analog-to-digital conversion circuit 2, a single electronic multiplexing circuit 3, a modulator 4 and an optical emitter 5 connected by an optical communication line 6 to an optical receiver 7.

The system III for collecting, processing and transmitting information contains: block 8 for collecting, processing and transmitting information, (N + 1) -channel block 9 for calculating the vertical component of the intensity vector, the input of which is connected to the output of block 8, block 10 for determining the maximum of the vertical component of the intensity vector the input of which is connected to the output of the (N + 1) -channel block 9 for calculating the vertical components of the intensity vector, the (N + 3) -channel block 11 for calculating the horizontal components of the intensity vector, the input of which is connected to the output of block 8 , processing and displaying information, (N + 1) -channel block 12 calculating the azimuthal angle, the input of which is connected to the first output of the (N + 3) -channel block 11 calculating the horizontal components of the intensity vector, block 13 calculating the averaged azimuthal angle, the first input of which connected to the output of the (N + 1) -channel block 12 calculating the azimuthal angle, and the second input is connected to the second output of the (N + 3) -channel block 11 calculating the horizontal components of the intensity vector.

In addition, the azimuthal angle calculation unit 14 for acoustic combined receivers P2 and P3, the input of which is connected to the third output of the (N + 3) -channel block 11 for calculating the horizontal components of the intensity vector, determination unit 15 is additionally included in the information collection, processing and transmission system the coordinates of the sound source, the first input of which is connected to the output of block 10 for determining the maximum of the vertical component of the intensity vector, the second input is connected to the output of block 13 for calculating the average azimuthal for the first acoustic combined receiver P1, the third input is connected to the output of the azimuthal angle calculation unit 14 for the acoustic combined receivers P2 and P3, the horizon of the acoustic combined receiver, which corresponds to the maximum vertical component of the intensity vector, determined in block 10 for determining the maximum vertical components of the intensity vector, and the horizontal coordinates of the sound source are the coordinates of the center of gravity triangles formed by the intersection of three position lines <φ ₁ > = const, φ ₂ = const, φ ₃ = const, corresponding to the three azimuthal angles <φ ₁ >, φ ₂ , φ ₃ . Information about the calculated coordinates of the sound source from the output of block 15 is fed to the input of block 16 of the access device to digital data networks.

Hydroacoustic complex works as follows.

The sound wave emitted by the sound source is received by acoustic combined receivers forming antenna I, in which the receivers P1, P2, P3 form the bottom orthogonal base, and the receiver P1 is supplemented by a vertically oriented equidistant antenna. All signals from the outputs of the acoustic receivers are fed to the input of the telemetry unit II, and after passing through the voltage dividers 1, the analog-to-digital conversion circuit 2 and the single electronic multiplexing circuit 3 are converted into a digital information stream coming through modulator 4, an optical emitter 5, and an optical line 6 communications to the optical receiver 7. From the output of the optical receiver 7, the information is received in digital form to the input of the unit 8 for collecting, processing and displaying information in the collection system III, processed and and display information. In block 8 for collecting, processing and displaying information, the signals are again separated by separate channels of sound pressure and components of the vibrational velocity vector and enter the (N + 1) -channel unit 9 for calculating the spectral density S _i (ω, r _i ) = ρ (ω, r _i ) V _z * (ω, r _i ) is the vertical power flow. In accordance with the results of the work [Schurov V.A., Kuleshov V.P., Tkachenko E.S. Vortices of acoustic intensity in the shallow sea // Technical Acoustics. 2010. No. 12. http://www.ejta.org. ] it is these quantities that have the greatest spatial correlation, are least affected by interference, and are connected by the simplest connection with the horizon of a sound source in a sound field formed in a shallow sea. These properties of the spectral density field of the vertical power flow are used in further processing of acoustic information. This processing is reduced to calculating the vertical component of the intensity vector I _z (ω, r _i ) = ReS _i (ω, r _i ) in block 9 for each of the N + 1 acoustic combined receivers and then finding the maximum of these values in block 10. For the horizon of the sound source is the horizon of the acoustic combined receiver, which corresponds to the maximum value of the vertical component of the intensity vector, and the corresponding information is fed to the first input of the block 15 for determining the coordinates of the sound source. The same signaling information from the output of information collection, processing, and display unit 8 is fed to the input of the (N + 3) -channel unit 11 for calculating the horizontal components of the intensity vector, from the first output of which the numerical values of the horizontal components of the intensity vector I _x (ω, r _i ) , I _y (ω, r _i ) are fed to the input of the (N + 1) -channel block 12 for calculating the azimuthal angle. Numerical estimates of the azimuthal angle to the sound source, calculated by formula (1) for each of the (N + 1) acoustic combined receivers, are averaged in block 13 by formula (3), and the averaged values of the azimuthal angle are transmitted to the second input of the source coordinate determination unit 15 sound. The very procedure of averaging individual values of the azimuthal angle allows us to reduce the random component of the measurement error of this quantity.

In addition, the azimuthal angle calculation unit 14 for acoustic combined receivers P2 and P3, the input of which is connected to the third output of the (N + 3) -channel block 11 for calculating the horizontal components of the intensity vector, determination unit 15 is additionally included in the information collection, processing and transmission system the coordinates of the sound source, the first input of which is connected to the output of block 10 for determining the maximum of the vertical component of the intensity vector, the second input is connected to the output of block 13 for calculating the average azimuthal for the first acoustic combined receiver P1, the third input is connected to the output of the azimuthal angle calculation unit 14 for the acoustic combined receivers P2 and P3, the horizon of the acoustic combined receiver, which corresponds to the maximum vertical component of the intensity vector, determined in block 10 for determining the maximum vertical components of the intensity vector, and the horizontal coordinates of the sound source are the coordinates of the center of gravity triangles formed by the intersection of three position lines <φ ₁ > = const, φ ₂ = const, φ ₃ = const, corresponding to the three azimuthal angles <φ ₁ >, ω ₂ , φ ₃ . Information about the calculated coordinates of the sound source from the output of block 15 is fed to the input of block 16 of the access device to digital data networks.

Claims (1)

A hydro-acoustic measuring complex containing N acoustic combined receivers, each of which consists of a hydrophone, a three-component vector receiver and amplifiers connected to them, a telemetry unit, the input of which is connected to the output of the acoustic combined receivers, including voltage dividers, an analog-to-digital conversion circuit, a single circuit electronic multiplexing, modulator and optical emitter, connected by an optical line of communication with an optical receiver, a collection system, processing information and data transmission, comprising a unit for collecting, processing and transmitting information, the input of which is connected to the output of the optical receiver, and a device for accessing digital data networks, characterized in that in the measuring complex through three acoustic combined receivers P1, P2, P3 is formed bottom orthogonal base, wherein the base distance L _x between detectors P1, P2 is oriented along the x axis, the base distance L _y is equal to the distance between the projection receivers P1, P3 on the y-axis orthogonal system local to rdinat and base distances are chosen from the condition $$L_x\ge \raisebox{1ex}{$H^2$}\!\left/ \!\raisebox{-1ex}{$\lambda $}\right.,L_y\ge \raisebox{1ex}{$H^2$}\!\left/ \!\raisebox{-1ex}{$\lambda $}\right.,$$

N additional acoustic combined receivers and receiver P1 form a bottom vertically oriented equidistant antenna, in which the distance between the acoustic combined receivers is equal to the specified error in determining the vertical coordinate (horizon) of the sound source Δz, and the number of receivers N = H / Δz, in the collection, processing and Information display additionally introduced (N + 1) -channel unit for calculating the vertical components of the intensity vector, the input of which is connected to the output of the collection unit, processing information display, a unit for determining the maximum of the vertical component of the intensity vector, the input of which is connected to the output of the (N + 1) -channel unit for calculating the vertical components of the intensity vector, (N + 3) -channel unit for calculating the horizontal components of the intensity vector, the input of which is connected to the output of the unit collection, processing and display of information, (N + 1) -channel block for calculating the azimuthal angle, the input of which is connected to the first output of the (N + 3) -channel block for calculating the horizontal components of the vector , the unit for calculating the averaged azimuthal angle, the first input of which is connected to the output of the (N + 3) -channel unit for calculating the azimuthal angle, the second input is connected to the second output of the (N + 3) -channel unit for calculating the horizontal components of the intensity vector, the azimuthal angle calculating unit for acoustic combined receivers P2 and P3, the input of which is connected to the third output of the (N + 3) -channel unit for calculating the horizontal components of the intensity vector, the unit for determining the coordinates of the sound source, the first input of which connected to the output of the unit for determining the maximum of the vertical component of the intensity vector, the second input is connected to the output of the unit for calculating the average azimuthal angle for the first acoustic combined receiver P1, the third input is connected to the output of the unit for calculating the azimuthal angles for acoustic combined receivers P2 and P3, and the output is connected to the input access devices to digital data networks, and the average azimuthal angle is determined by the formula
$$〈{\phi }_{\mathrm{one}}〉={\displaystyle \sum _{n=\mathrm{one}}^{N+\mathrm{one}}{\phi }_n\frac{I_{xn}^2+I_{yn}^2}{I^2},I^2={\displaystyle \sum _{n=\mathrm{one}}^{N+\mathrm{one}}(I_{xn}^2+I_{yn}^2)}},$$

where φ _n , I _xn , I _yn is the azimuthal angle and the horizontal components of the intensity vector related to the ny acoustic combined receiver, the horizon of the sound source is the horizon of the acoustic combined receiver, which corresponds to the maximum of the vertical component of the intensity vector, and the horizontal coordinates of the sound source are taken the coordinates of the center of gravity of the triangle formed by the intersection of three lines of position <φ _1> = const, φ ₂ = const, φ ₃ = const for three azimuthal angles <φ _1>, φ _2, φ ₃ corresponds permanently.

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