A method and device for locating pulse sound source on ice using single vector hydrophone

Abstract

The present invention belongs to the field of polar acoustic technology, and specifically relates to a method and device for locating pulse sound sources on ice using a single vector hydrophone, and performing cross-ice positioning in sea areas covered by polar sea ice. Existing methods cannot well realize the construction of a three-dimensional observation platform in polar regions, and it is necessary to develop new communication technologies to overcome this problem and improve the information transmission capabilities between submarines and other communication equipment. Based on the theory of polar sound propagation, the present invention explores the mapping relationship between the arrival time of different modal wave fields and the spatial position of the sound source, and utilizes the characteristics of the vector hydrophone that can simultaneously receive the amplitude and direction information of the sound wave velocity, and implements the evaluation of the height and distance of the air pulse sound source based on a single array element. The signal attenuation in a complex ice and water environment is reduced, and the signal propagation quality is improved. The cross-medium detection of airborne sound sources underwater can be realized more covertly, while reducing costs and construction risks.

Description

Technical Field

[0001] The present invention belongs to the field of polar acoustic technology, and specifically relates to a method and device for locating an ice pulse sound source by using a single vector hydrophone, and performing cross-ice layer positioning in a sea area covered with polar sea ice. Background Art

[0002] The Arctic region is a new space for the global governance system, so achieving cross-media aerial sound source underwater detection is of great significance to the formation of cross-domain perception in the polar regions.

[0003] Due to meteorological conditions, the Arctic sea ice hinders ships and makes it difficult for surface vessels to easily enter the core area of ​​the Arctic. The widespread presence of sea ice also limits the scope of information exchange between the atmosphere and sea water. Therefore, a more efficient communication method is needed to achieve effective information transmission.

[0004] The coverage of radars over the polar regions is significantly limited due to the absorption of electromagnetic waves by ice and water. Especially for long-range radars, the low-altitude blind spots in the polar environment make it impossible to accurately monitor aerial targets, which poses a huge threat to security, environmental monitoring and aviation activities in the Arctic region.

[0005] In addition, even if the radar detects an aerial target, the absorption and attenuation of electromagnetic waves in the ice-water medium will severely limit the transmission of information to underwater submersibles and other equipment. In the marine environment, acoustic observation is a common method, but in the polar regions it is more used in waters under the ice. If you want to achieve cross-ice detection of aerial targets, you usually need to arrange relay equipment on the ice surface to receive the signals generated by the aerial targets and transmit the signals to the underwater submersible. However, this method has the problems of poor concealment, increased cost burden and construction risks.

[0006] In summary, existing methods cannot effectively build a three-dimensional observation platform in the polar region. Therefore, it is necessary to develop new communication technologies to overcome this problem and improve the information transmission capabilities between submarines and other communication equipment. Summary of the invention

[0007] In view of the problems that the use of electromagnetic wave methods in the prior art is limited and the ice-based detectors are inconvenient to use, the present invention proposes a method and device for locating pulse sound sources on ice using a single vector hydrophone, thereby achieving accurate positioning of aerial targets in a polar environment.

[0008] The acoustic energy generated by the airborne pulse sound source can be transmitted into the water across the ice layer through the fluid-solid coupling boundary. During the process, the acoustic energy propagates along multiple paths and at different speeds, resulting in the complexity of the underwater sound field. Based on the polar sound propagation theory, the present invention explores the mapping relationship between the arrival time of different modal wave fields and the spatial position of the sound source, and utilizes the characteristics of the vector hydrophone that can simultaneously receive the pressure, velocity and direction information of the sound wave, and evaluates the height and distance of the airborne pulse sound source based on a single array element.

[0009] The cross-medium sound propagation path used in the present invention includes a direct wave path in water ( Figure 2 Path 1) and inter-ice plate longitudinal wave path ( Figure 2 Middle path 2).

[0010] Direct wave path in water: The pulse sound source S in the air excites the sound field. The sound waves reach the ice layer directly below the sound source and cause the ice layer to vibrate. The sound waves propagate in the water in the form of spherical diffusion at the lower surface S′ of the ice layer.

[0011] The path of longitudinal waves between ice sheets: The airborne pulse sound source S excites the sound field, and the sound waves are incident at a specific angle. ( The sound waves are incident on the upper surface of the ice layer, and the ice layer vibrates to excite longitudinal waves between the plates. While the sound waves propagate in the ice layer, part of the sound energy continues to leak into the water through the ice-water interface at a specific leakage angle γ (γ is the angle between the propagation direction and the ice surface normal). , specific leakage angle γ and air sound speed c a 、Longitudinal wave speed between ice sheets c p and the speed of sound in water c w The angle value can be obtained according to Snell's law:

[0012]

[0013] The present invention proposes a method for locating an ice pulse sound source using a single vector hydrophone, the method comprising the following steps:

[0014] S1, using a single vector hydrophone to receive the sound wave signal S0 excited by the air pulse sound source S underwater;

[0015] S2, separating the signal S1 propagating along the direct wave path in the water and the signal S2 propagating along the longitudinal wave path between the ice sheets from the acoustic wave signal S0;

[0016] S3, extract the vector medium particle velocity information of signal S1 , calculate the azimuth angle α of the air pulse sound source S relative to the underwater receiving point O and the pitch angle β of the direct wave in the water;

[0017] S4, calculating the time delay of the vector hydrophone receiving signals of different paths through geometric relationships;

[0018] S5. Establishing the positioning equation of the air pulse sound source according to the propagation delay information;

[0019] S6. Solve the positioning equation to obtain the distance and height information of the air pulse sound source.

[0020] Advantageously, the vibration velocity information in S3 but:

[0021] α=arctan(V y / V x )

[0022]

[0023] Advantageously, in S4, the delay of signal S1 is t1, and the delay of signal S2 is t2:

[0024]

[0025]

[0026]

[0027]

[0028] Where h is the underwater depth of the vector hydrophone, x is the height of the airborne pulse sound source S from the ice surface, and c a The speed of sound in air, c p is the sound velocity of longitudinal waves between ice sheets, c w is the speed of sound in water, is a specific incident angle, and γ is a specific leakage angle.

[0029] Advantageously, in S5, the time delay difference between the two signal paths is recorded as Δt, Δt=t1-t2, then the positioning equation of the air pulse sound source is:

[0030]

[0031] Advantageously, in S6, the height x of the air pulse sound source S from the ice surface is first calculated, and the horizontal distance D and vertical distance H of the air pulse sound source S relative to the underwater receiving point O are calculated based on the geometric relationship, thereby determining the coordinates of the air pulse sound source S as (Dcosα, Dsinα, H).

[0032] The present invention also proposes a device for locating an impulse sound source on ice using a single vector hydrophone, and the device is used to execute the above-mentioned positioning method.

[0033] Advantageously, the device includes a processing module, which processes the acoustic wave signal S0 excited by the air pulse sound source S received by the single vector hydrophone underwater, separates the signal S1 propagating along the direct wave path in the water and the signal S2 propagating along the longitudinal wave path between the ice sheets from the acoustic wave signal S0; extracts the vector medium particle velocity information of the signal S1 , calculate the azimuth angle α of the air pulse sound source S relative to the underwater receiving point O and the pitch angle β of the direct wave in the water; calculate the time delay of the vector hydrophone receiving signals from different paths through geometric relationships; establish the positioning equation of the air pulse sound source based on the propagation delay information; solve the positioning equation to obtain the distance and height information of the air pulse sound source.

[0034] Advantageously, the vibration velocity information but:

[0035] α=arctan(V y / V x )

[0036]

[0037] Advantageously, the time delay of signal S1 is t1, and the time delay of signal S2 is t2:

[0038]

[0039]

[0040]

[0041]

[0042] Where h is the underwater depth of the vector hydrophone, x is the height of the airborne pulse sound source S from the ice surface, and c a The speed of sound in air, c p is the sound velocity of longitudinal waves between ice sheets, c w is the speed of sound in water, is a specific incident angle, and γ is a specific leakage angle.

[0043] Advantageously, the time delay difference between the two signal paths is recorded as Δt, Δt=t1-t2, then the positioning equation of the air pulse sound source is:

[0044]

[0045] Beneficial effects: Based on the channel analysis of sound propagation across air-ice-water media, the present invention uses two natural independent channels for sound energy to propagate across ice layers in polar ice environments: the direct wave propagation channel in water and the longitudinal wave propagation channel between ice sheets. This method can achieve cross-ice layer assessment of the distance and height of airborne pulse sound sources using a single vector hydrophone. Its beneficial effects are shown in the following aspects:

[0046] (1) High positioning accuracy

[0047] Compared with traditional radar and electromagnetic wave technology, the present invention adopts sound wave propagation, which reduces signal attenuation in complex ice and water environments and improves signal propagation quality, making positioning accuracy in polar regions more reliable and effective.

[0048] (2) Long detection distance

[0049] Compared with electromagnetic waves, sound waves attenuate less in ice-water media, which means that sound waves can propagate over longer distances, making it possible to detect distant targets.

[0050] (3) High concealment

[0051] There is no need to deploy relay equipment on the ice surface, which reduces the exposure risk of underwater submersibles and other equipment. Cross-media detection of aerial sound sources underwater can be achieved more covertly, while reducing costs and construction risks.

[0052] The features, functions, and advantages that have been discussed can be achieved independently in various examples or may be combined in yet other examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Examples, as well as preferred modes of use, other purpose machine descriptions, will be best understood by reference to the following detailed description of examples of the invention when read in conjunction with the accompanying drawings, in which:

[0054] Figure 1 It is a flow chart of the pulse sound source localization method of the present invention;

[0055] Figure 2 It is a two-dimensional scene schematic diagram of the positioning principle of the present invention;

[0056] Figure 3 It is a schematic diagram of pitch angle and azimuth angle. DETAILED DESCRIPTION

[0057] The disclosed examples will be more fully described with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples may be described and these examples should not be construed as limited to the examples set forth herein. On the contrary, describing these examples makes the disclosure of the present invention thorough and complete and will fully convey the scope of the present disclosure to those skilled in the art.

[0058] refer to Figure 1 As shown in the flowchart, the method for locating the pulse sound source on ice of the present invention comprises the following steps:

[0059] Step 1: Use a single vector hydrophone to receive the sound wave signal excited by the pulse sound source S in the air underwater, recorded as S0.

[0060] like Figure 2 As shown, the sound waves excited by the air pulse sound source S propagate along path 1 and path 2 at the same time. A single vector hydrophone is used to receive the mixed sound wave signal of path 1 and path 2 at the underwater receiving point O, which is recorded as S0, and the time delay difference is Δt.

[0061] Step 2: Use signal processing technology to separate the signal S1 propagating along path 1 and the signal S2 propagating along path 2 from the received mixed sound wave signal S0.

[0062] Step 3: Extract the vector medium particle velocity information of signal S1 , calculate the azimuth angle α of the air pulse sound source S relative to the underwater receiving point O and the pitch angle β of the direct wave in the water.

[0063] Use a single vector hydrophone to obtain the vector medium particle velocity information of the direct wave in the water at the underwater receiving point O

[0064] like Figure 3 As shown, the airborne pulse sound source S has an azimuth angle α in the horizontal plane relative to the vector hydrophone, as Figure 2 As shown, the direct wave in water has a pitch angle β:

[0065] α=arctan(V y / V x )

[0066]

[0067] Step 4: Calculate the time delay of the vector hydrophone receiving signals from different paths.

[0068] The vector hydrophone receives signals S1 and S2 at the underwater receiving point O. The propagation delay of signal S1 from the air pulse sound source S to the underwater receiving point O via path 1 is t1, and the propagation delay of signal S2 from the air pulse sound source S to the underwater receiving point O via path 2 is t2.

[0069] like Figure 2 As shown, h is the underwater depth of the vector hydrophone, and x is the height of the air pulse sound source S from the ice surface. a 、Longitudinal wave speed between ice sheets c p and the speed of sound in water cw .x / c a is the time delay of the sound wave from the air pulse sound source S to the upper surface of the ice layer after vertical incidence. Since the time delay of the sound wave from the upper surface of the ice layer to the lower surface of the ice layer is short, it can be ignored. is the time delay of the direct wave in the water propagating from point S′ on the lower surface of the ice layer to the underwater receiving point O of the single vector hydrophone. The time delay relationship of the direct wave in the water received by the single vector hydrophone can be obtained as follows:

[0070]

[0071] After exciting the sound wave from the air pulse sound source, it The time delay required for incident light to reach the upper surface of the ice layer; It is the time delay required for the longitudinal wave between plates to propagate a certain distance in the ice layer; is the time delay required for the inter-plate longitudinal wave to propagate from the lower surface of the ice layer to the underwater receiving point O at a specific leakage angle γ. The time delay relationship for the single vector hydrophone to receive the inter-plate longitudinal wave in the ice layer can be obtained as follows:

[0072]

[0073] Step 5: Establish the positioning equation of the air pulse sound source based on the propagation delay information.

[0074] The time delay difference between the two signal paths is recorded as Δt, Δt = t1-t2, and the positioning equation of the air pulse sound source is:

[0075]

[0076] Step 6: Solve the positioning equation to obtain the distance and height information of the air pulse sound source.

[0077] Specifically, the speed of sound in air c a , the speed of sound of longitudinal waves in ice c p 、Sound speed in water c w , angle of incidence , leakage angle γ, pitch angle β of the direct wave in water, underwater depth h of the vector hydrophone, propagation delay difference Δt between the direct wave in water and the longitudinal wave between the ice plates received by the vector hydrophone are all known quantities, and the height x of the air pulse sound source S from the ice surface can be calculated.

[0078] like Figure 3 The geometric relationship is shown:

[0079]

[0080] Where ψ is the pitch angle of the air pulse sound source relative to the underwater receiving point O.

[0081] Specifically, the horizontal distance D, vertical distance H, pitch angle ψ, and azimuth angle α of the air pulse sound source S relative to the underwater receiving point O can all be obtained. Further, a Cartesian space coordinate system is established with the point O where the vector hydrophone is located as the origin. From the geometric relationship, it can be seen that the coordinates of the air pulse sound source S are (Dcosα, Dsinα, H).

[0082] The purpose of the examples and descriptions presented has been to illustrate descriptions of different advantageous arrangements, but the descriptions are not intended to be exclusive or limited to examples of the disclosed form. Many modifications and variations will be apparent to those skilled in the art. In addition, different advantageous examples may be described as having different advantages compared to other advantageous examples. The selected example or examples are selected and described in order to best illustrate the principles of the examples, practical applications, and to enable those of ordinary skill in the art to understand the disclosure of various examples with various modifications suitable for the particular use contemplated.

Claims

1. A method for locating an ice pulse sound source using a single vector hydrophone, characterized in that: The method comprises the following steps: S1, using a single vector hydrophone to receive the sound wave signal S0 excited by the air pulse sound source S underwater; S2, separating the signal S1 propagating along the direct wave path in the water and the signal S2 propagating along the longitudinal wave path between the ice sheets from the acoustic wave signal S0; S3, extract the vector medium particle velocity information of signal S1 The azimuth angle α of the air pulse sound source S relative to the underwater receiving point O and the pitch angle β of the direct wave in the water are calculated; wherein the vibration velocity information but: α=arctan(V y / V x ) S4, calculating the time delay of the vector hydrophone receiving signals of different paths through geometric relationships; The delay of signal S1 is t1, and the delay of signal S2 is t2: Where h is the underwater depth of the vector hydrophone, x is the height of the airborne pulse sound source S from the ice surface, and c a The speed of sound in air, c p is the sound velocity of longitudinal waves between ice sheets, c w is the speed of sound in water, is the specific incident angle, γ is the specific leakage angle; S5. Establishing the positioning equation of the air pulse sound source according to the propagation delay information; S6. Solve the positioning equation to obtain the distance and height information of the air pulse sound source.

2. The method for locating an ice pulse sound source using a single vector hydrophone according to claim 1, characterized in that: In S5, the time delay difference between the two signal paths is recorded as Δt, Δt = t1-t2, then the positioning equation of the air pulse sound source is:

3. The method for locating an ice pulse sound source using a single vector hydrophone according to claim 2, characterized in that: In S6, the height x of the air pulse sound source S from the ice surface is first calculated, and the horizontal distance D and vertical distance H of the air pulse sound source S relative to the underwater receiving point O are calculated based on the geometric relationship, thereby determining the coordinates of the air pulse sound source S as (Dcosα, Dsinα, H).

4. A device for locating an impulse sound source on ice using a single vector hydrophone, characterized in that: The device is used to execute the positioning method as described in any one of claims 1 to 3.

5. The device for locating an impulse sound source on ice using a single vector hydrophone according to claim 4, characterized in that: The device includes a processing module, which processes the sound wave signal S0 excited by the air pulse sound source S received by the single vector hydrophone underwater, separates the signal S1 propagating along the direct wave path in the water and the signal S2 propagating along the longitudinal wave path between ice sheets from the sound wave signal S0; extracts the vector medium particle velocity information of the signal S1 Calculate the azimuth angle α of the air pulse sound source S relative to the underwater receiving point O and the pitch angle β of the direct wave in the water; calculate the time delay of the vector hydrophone receiving signals from different paths through geometric relationships; The positioning equation of the airborne pulse sound source is established based on the propagation delay information; The positioning equation is solved to obtain the distance and height information of the pulse sound source in the air.

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