CN113495275A - Passive positioning method, system and application for vertical synthetic aperture of single hydrophone - Google Patents

Abstract

The invention belongs to the technical field of underwater target detection, and discloses a passive positioning method, system and application of a single hydrophone vertical synthetic aperture, constructing a single hydrophone synthetic vertical aperture strategy and a sound field model; Motion velocity estimation; define distance-depth ambiguity function to estimate target distance and depth; define distance cost function to improve target distance and depth estimation accuracy, and obtain optimal target position. Aiming at the problems of high design complexity, difficult deployment, and difficult attitude control of long-aperture vertical arrays, the present invention utilizes a single hydrophone to vertically move to realize the vertical array synthetic aperture, and combines the vertical array matching field passive positioning method to estimate underwater targets. Position and movement speed; under the premise of reducing the complexity of system design and layout, give full play to the advantages of vertical array target detection, provide new ideas for underwater moving platforms to detect targets, and provide technical support for improving the detection capabilities of moving platforms.

Description

A passive positioning method, system and application of a single hydrophone vertical synthetic aperture

technical field

The invention belongs to the technical field of underwater target detection, and in particular relates to a single hydrophone vertical synthetic aperture passive positioning method, system and application.

Background technique

At present, the radiated noise of targets in water is mostly concentrated in the low frequency band, and the wavelength of the sound wave is long. Whether it is the target azimuth resolution ability or the target positioning accuracy, higher requirements are put forward for the sonar aperture. Compared with a single hydrophone or a short aperture array, the design complexity and engineering deployment difficulty of a long array sonar system are significantly improved. Therefore, the passive detection technology of synthetic aperture sonar based on a single hydrophone or a short array is widely used. It is widely used in underwater acoustic countermeasures and target detection and positioning.

Scholars at home and abroad have also done a lot of theoretical and experimental research on the matching field passive localization method based on vertical array. The research results show that compared with horizontal array, vertical array has certain advantages in low-frequency target detection and localization. However, in practical applications, since the vertical array has great disadvantages in deployment and attitude control, especially for moving carriers, and in the deep sea environment, it is difficult to ensure the effective aperture of the vertical array.

(1) Long aperture vertical array has high design complexity and poor engineering practicability

Long-aperture vertical arrays have problems such as high design complexity, difficult deployment, and difficult attitude control. Especially for moving carriers, the deployment of long-aperture vertical arrays is almost impossible, which also limits the application of vertical arrays. A single hydrophone synthetic aperture can simplify the system design complexity and improve the maneuverability and flexibility of the detection system.

(2) The underwater motion detection platform lacks effective vertical array synthesis technology

At present, distributed detection methods based on small motion platforms have been widely concerned and applied. Multi-platform cooperation requires information transmission, and the detection capability of a single platform is limited. In order to improve the detection capability of a single platform, it is necessary to carry out research on vertical synthetic aperture technology based on a single platform with vertical motion, and give full play to the advantages of vertical arrays in the application of underwater target detection.

At present, small underwater platforms such as underwater gliders, UUVs, wave gliders, and submersible buoy systems are widely used in the field of underwater target detection. Using the vertical movement information of the underwater movement detection platform and the acoustic data obtained during the movement, through The vertical synthetic aperture technology fully exploits the advantages of array processing in acoustic detection, provides new detection methods for small moving platforms, and improves the acoustic detection capabilities of moving platforms.

Although the horizontal synthetic aperture technology and its corresponding positioning methods are relatively mature, there are few public reports on the vertical synthetic aperture positioning method. Therefore, the vertical synthetic aperture also provides a new idea for the underwater motion platform to detect underwater targets.

Through the above analysis, the existing problems and defects in the prior art are:

(1) Long-aperture vertical arrays have problems such as high design complexity, difficult deployment, and difficult attitude control. Especially for moving carriers, the deployment of long-aperture vertical arrays is almost impossible, which limits the application of vertical arrays.

(2) The underwater motion detection platform lacks effective vertical array synthesis technology, information transmission is required for multi-platform cooperation, and the detection capability of a single platform is limited.

(3) There are few public reports about the vertical synthetic aperture positioning method.

The difficulty of solving the above problems and defects is as follows:

(1) The moving platform cannot carry the vertical array. The vertical array can only work in the form of submersible buoys and fixed platforms. The moving platform is the main carrier of the sonar system. The vertical array detection technology of the moving platform needs to find another way.

(2) At present, the synthetic aperture technology is mostly used in the horizontal direction, and the vertical synthetic aperture technology for the underwater sports platform needs to be developed urgently.

(3) Designing a single-hydrophone vertical synthetic aperture method of mode base matching, and realizing the "1+2" dimension parameter estimation algorithm of speed and distance + depth is the key to realize passive positioning.

The significance of solving the above problems and defects is:

(1) Under the premise of reducing the complexity of vertical array system design and deployment, the advantages of vertical array target detection can be fully utilized, and it is suitable for UUV, AUV, glider and other platforms.

(2) In line with the current development trend of small platform detection technology, it provides new detection methods for moving small platforms, and provides technical support for improving the detection capability of a single underwater small platform.

(3) The vertical synthetic aperture processing of a single hydrophone can effectively reduce the amount of information transmission and reduce the pressure of data communication for multi-platform cooperation.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the prior art, the present invention provides a single hydrophone vertical synthetic aperture passive positioning method, system and application, aiming to solve the problems of high design complexity, difficult deployment and difficult attitude control of long aperture vertical arrays. And other issues.

The present invention is realized like this, a kind of single hydrophone vertical synthetic aperture passive positioning method, described single hydrophone vertical synthetic aperture passive positioning method comprises the following steps:

The first step is to construct a single hydrophone synthetic vertical aperture strategy and sound field model; provide the theoretical basis for the passive positioning of the single hydrophone vertical synthetic aperture and a forward sound field model for matching processing.

Step 2: Define the velocity cost function and estimate the radial motion velocity of the target; by measuring the environmental data and calculating the sound field model, using the model-based matching and optimization algorithm, the target motion information is obtained, and the a priori information is provided for the target distance-depth estimation .

Step 3: Define the distance-depth ambiguity function, and estimate the target distance and depth; on the premise of known radial motion velocity, combined with the traditional matching field processing idea, provide the ambiguity function for estimating the target distance and depth, which is as follows: The premise of accurately estimating the target position in one step.

Step 4: Define the cost function of distance estimation, improve the accuracy of target distance estimation, and obtain the optimal target position estimation result; use the target distance-depth ambiguity function to further define the cost function of distance estimation, reduce the influence of side lobes and multi-values, and improve the distance Estimate the accuracy and give the optimal target position estimation result.

Further, in step 1, described constructing single hydrophone synthetic vertical aperture strategy and sound field model, including:

Assume that the target moves at a constant speed along the angle θ between the horizontal line connecting the target and the hydrophone, the velocity is V, the radial velocity v=Vcosθ, and the target radiates a simple harmonic signal with a circular frequency of ω; the non-directional hydrophone Do a uniform motion in the depth direction, and the moving speed is u. The depth of the hydrophone at time 0 is z ₀ , and the depth H of the ocean floor at time T moves. Taking the hydrophone at time 0 as the reference point, assuming that the unknown horizontal distance of the target is r ₀ and the target depth is z _s , it can be approximately equivalent geometrically that the target is stationary, and the vertical velocity of the hydrophone is u, Horizontal movement speed is -v.

If the marine environment information is known, the normal wave eigenwave number k _n and the eigenfunction Φ _n (z) are calculated, and the sound pressure analysis signal received by the hydrophone in the time t∈[0,T] is:

in,

If the moving target is used as the reference point, the movement trajectory of the hydrophone can be synthesized into an inclined line array. The horizontal spacing of the array elements is ΔR=vcosθΔt, the vertical spacing is ΔZ=uΔt, and Δt is the vertical array synthesis sampling time. The n-th equivalent array element, that is, the signal received at the n-th sampling time is:

Further, the method for obtaining the marine environment information is as follows: attaching a temperature and pressure sensor during the lowering of the hydrophone to measure the temperature profile and the actual depth of the hydrophone at different times.

Further, in step 2, the target radial motion velocity estimation includes:

Similar to the weighted wave number forming process, set the target moving speed interval v'∈[V ₁ ,V ₂ ], take exp(-ik _m v't) as the "steering" vector, the eigenfunction Φ _m of the mth normal wave (z ₀ +ut) does the following for the weighted vector:

In the numerical integration of formula (3), the time step should satisfy vΔt<λ, that is, the horizontal spacing of the synthetic aperture is smaller than the wavelength of the acoustic wave. Without loss of generality, let z ₀ =0, uT = H, and H is the depth of the water body.

According to the orthogonality of normal waves, when n=m and v'=v, |F _m | takes the maximum value.

Define the cost function that determines the speed of the target movement:

The maximum value of the cost function corresponds to an estimate of the radial velocity of the target:

Further, in step 3, the defined distance-depth ambiguity function includes:

Write equation (3) in matrix form:

F=MS (6)

in,

F=[F ₁ (v),F ₁ (v),...,F _N (v)] ^T ;

Then there are:

S = M ^-1 F (8)

The ambiguity function that defines the estimated target distance and depth (r-z) is:

Substituting equation (7) into equation (9), when r=r0, the ambiguity function can be approximately expressed as:

The distance and depth corresponding to the maximum value of the ambiguity function RD are the target distance and depth:

Further, in step 4, the defined distance estimation cost function includes:

Similar to the matching field processing method, Equation (11) is used to estimate the position of the sound source, and multiple maxima appear in the r-z ambiguity plane. In order to better judge the real position, the normalized cost function |RD(r,z) | is:

Define the distance cost function to examine the accuracy of depth estimation at different distances:

in,

Then the estimated distance is:

The optimal target position estimation result is:

(r _s ,z _s )=(r _max ,z _max (r _max )) (15)

Another object of the present invention is to provide a single hydrophone vertical synthetic aperture passive positioning system applying the single hydrophone vertical synthetic aperture passive positioning method, and the single hydrophone vertical synthetic aperture passive positioning system comprises:

Model building module for building a single hydrophone synthetic vertical aperture strategy and sound field model;

The motion velocity estimation module is used to estimate the radial motion velocity of the target by defining the velocity estimation cost function;

The target position estimation module is used to estimate the target distance and depth by defining the distance-depth ambiguity function;

The target position estimation module is used to improve the target distance and depth estimation accuracy by defining the distance estimation cost function, and obtain the optimal target position estimation result.

Another object of the present invention is to provide a computer device, the computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the following step:

(1) Build a synthetic vertical aperture strategy and sound field model for a single hydrophone;

(2) Define the speed estimation cost function to estimate the radial motion speed of the target;

(3) Define the distance-depth ambiguity function to estimate the target distance and depth;

(4) Define the cost function of distance estimation, improve the accuracy of target distance and depth estimation, and obtain the optimal target position.

Another object of the present invention is to provide a computer-readable storage medium that stores a computer program, and when the computer program is executed by a processor, the processor performs the following steps:

(1) Build a synthetic vertical aperture strategy and sound field model for a single hydrophone;

(2) Define the speed estimation cost function to estimate the radial motion speed of the target;

(3) Define the distance-depth ambiguity function to estimate the target distance and depth;

(4) Define the cost function of distance estimation, improve the accuracy of target distance and depth estimation, and obtain the optimal target position.

Another object of the present invention is to provide an information data processing terminal for implementing the single hydrophone vertical synthetic aperture passive positioning system.

Combined with all the above technical solutions, the advantages and positive effects of the present invention are as follows: theoretical and experimental studies show that the passive positioning technology based on vertical array has certain advantages in passive detection and positioning of low-frequency underwater acoustic targets. Aiming at the problems of high design complexity, difficult deployment, and difficult attitude control of long-aperture vertical arrays, the present invention utilizes a single hydrophone that moves vertically to realize the vertical array synthetic aperture, and combines the vertical array matching field passive positioning method to estimate underwater Information such as target position and movement speed. Under the premise of reducing the complexity of system design and layout, the present invention gives full play to the advantages of vertical array target detection, provides new ideas for the detection of targets of the underwater moving platform, and provides technical support for improving the detection capability of the moving platform. Meanwhile, the single hydrophone vertical synthetic aperture passive positioning method provided by the present invention also has the following effects:

(1) Low system design complexity

The passive positioning system based on a single hydrophone vertical array synthetic aperture has low design complexity. Compared with the long aperture vertical array detection system, this method only needs one hydrophone or a short array composed of several hydrophones.

(2) Suitable for a variety of installation platforms

The vertical array synthetic aperture is matched with pressure sensor and carrier hydrology winch (or other crane). Ship-borne winch, underwater unmanned motion platform, submersible buoy system.

(3) Diversified detection methods

It can work on a single base or in distributed collaboration. Whether it is a ship-borne method or an underwater unmanned platform or a submersible buoy system, it can realize a multi-platform cooperation mode, which is suitable for large-scale distributed detection, which greatly improves the mobility and flexibility of the detection system.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following will briefly introduce the accompanying drawings that need to be used in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a flowchart of a method for passively positioning a vertical synthetic aperture of a single hydrophone according to an embodiment of the present invention.

2 is a structural block diagram of a single hydrophone vertical synthetic aperture passive positioning system provided by an embodiment of the present invention;

In the figure: 1. Model building module; 2. Movement velocity estimation module; 3. Target parameter calculation module; 4. Target position estimation module.

FIG. 3 is a schematic diagram of a vertical array synthetic aperture of a single hydrophone provided by an embodiment of the present invention.

Fig. 3 (a) is that the target provided by the embodiment of the present invention moves at a constant speed along the direction of the included angle θ between the target and the hydrophone, and the hydrophone moves at a constant speed along the depth direction at a speed u while the target moves. Schematic diagram of the movement.

Figure 3(b) is a schematic diagram of a synthetic aperture provided by an embodiment of the present invention. Assuming that the target is fixed, an inclined linear array can be synthesized according to the depth of the hydrophone at different times and the distance from the target. The horizontal spacing of the array elements is ΔR =vΔt, the vertical spacing is ΔZ=uΔt, and Δt is the synthetic aperture sampling time.

FIG. 4 is a top view of the relative position and motion state of the target and the hydrophone provided by an embodiment of the present invention.

FIG. 5 is a schematic diagram of a target radial velocity estimation result (velocity 5 m/s) provided by an embodiment of the present invention.

Fig. 6 is a schematic diagram of a target distance-depth estimation result provided by an embodiment of the present invention (distance 6km, depth 30m).

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

In view of the problems existing in the prior art, the present invention provides a method, system and application for passive positioning of a single hydrophone vertical synthetic aperture. The present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figure 1, the single hydrophone vertical synthetic aperture passive positioning method provided by the embodiment of the present invention comprises the following steps:

S101, build a single hydrophone synthetic vertical aperture strategy and sound field model;

S102, define a speed estimation cost function, and perform target radial motion speed estimation;

S103, define a distance-depth ambiguity function, and estimate the target distance and depth;

S104, define a distance estimation cost function, improve the distance and depth estimation accuracy, and obtain an optimal target position estimation result.

As shown in Figure 2, the single hydrophone vertical synthetic aperture passive positioning system provided by the embodiment of the present invention includes:

Model building module 1, used to build a single hydrophone synthetic vertical aperture strategy and sound field model;

The motion speed estimation module 2 is used to estimate the radial motion speed of the target by defining the cost function of speed estimation;

The target parameter calculation module 3 is used to estimate the target distance and depth by defining a distance-depth ambiguity function;

The target position estimation module 4 is used to improve the distance and depth estimation accuracy by defining the distance estimation cost function, and obtain the optimal target position estimation result.

The technical solutions of the present invention will be further described below in conjunction with the embodiments.

Example 1

Theoretical and experimental studies show that the passive localization technology based on vertical array has certain advantages in passive detection and localization of low-frequency underwater acoustic targets. In view of the problems of high design complexity, difficult deployment, and difficult attitude control of long-aperture vertical arrays, a single hydrophone that moves vertically is used to realize the vertical array synthetic aperture, and combined with the passive positioning method of the vertical array matching field, the underwater target position is estimated. and movement speed. Under the premise of reducing the complexity of system design and layout, the advantages of vertical array target detection are given full play, new ideas are provided for the detection of targets of underwater moving platforms, and technical support is provided for improving the detection capabilities of moving platforms.

The passive positioning method for the vertical synthetic aperture of a single hydrophone provided by the embodiment of the present invention includes:

Step 1: Single-hydrophone synthetic vertical aperture strategy and sound field model

In order to simplify the vertical synthetic aperture model, the layered dielectric waveguide with constant level is considered here, and the basic principle of the vertical synthetic aperture is analyzed and discussed by using the normal wave method. Assume that the target moves at a uniform speed along the angle θ between the target and the horizontal line connecting the target and the hydrophone, the velocity is V, the radial velocity v=Vcosθ, and the target radiates a simple harmonic signal with a circular frequency of ω; the non-directional hydrophone Do a uniform motion in the depth direction, and the moving speed is u. The depth of the hydrophone at time 0 is z ₀ , and the depth H of the ocean floor at time T moves. Assume that the unknown horizontal distance of the target (with the hydrophone at time 0 as the reference point) is r ₀ , and the depth of the target is z _s , as shown in Figure 3(a). This can be approximately equivalent geometrically as the target is stationary, the vertical motion speed of the hydrophone is u, and the horizontal motion speed is -v, as shown in Fig. 3(b). Figure 4 is a top view of the positional relationship between the target and the hydrophone.

If the marine environment information is known (a temperature and pressure sensor can be attached during the deployment of the hydrophone to measure the temperature profile and the actual depth of the hydrophone at different times), the normal wave eigenwave number k _n and the eigenfunction Φ _n can be calculated ( z), the sound pressure analysis signal received by the hydrophone in the time t∈[0,T] is:

如果以运动目标作为参考点，水听器的移动 轨迹可以合成一条倾斜的线列阵，阵元水平间距为ΔR＝vcosθΔt，垂直间距为 ΔZ＝uΔt，Δt为垂直阵合成采样时间，如图3(b)所示。第n个等效阵元(第n个采样 时刻)接收的信号为：in,

If the moving target is used as the reference point, the movement trajectory of the hydrophone can be synthesized into an inclined line array. The horizontal spacing of the array elements is ΔR=vcosθΔt, the vertical spacing is ΔZ=uΔt, and Δt is the vertical array synthesis sampling time, as shown in Figure 3 (b). The signal received by the n-th equivalent array element (the n-th sampling time) is:

Step 2: Target radial motion velocity estimation method

Similar to the weighted wave number forming process, set the target moving speed interval v'∈[V ₁ ,V ₂ ], take exp(-ik _m v't) as the "steering" vector, the eigenfunction Φ _m of the mth normal wave (z ₀ +ut) does the following for the weighted vector:

In order to prevent the occurrence of grating lobes, in the numerical integration of equation (3), the time step should satisfy vΔt<λ, that is, the horizontal spacing of the synthetic aperture is smaller than the wavelength of the acoustic wave. Without loss of generality, let z ₀ =0, uT = H, and H is the depth of the water body.

According to the orthogonality of normal waves, when n=m and v'=v, |F _m | takes the maximum value. Define the cost function that determines the speed of the target movement:

The maximum value of the cost function corresponds to an estimate of the radial velocity of the target:

Step 3: Distance-Depth Ambiguity Function

Write equation (3) in matrix form:

F=MS (6)

in,

F=[F ₁ (v),F ₁ (v),...,F _N (v)] ^T ;

Then there are:

S = M ^-1 F (8)

The ambiguity function that defines the estimated target distance and depth (r-z) is:

Substituting equation (7) into equation (9), when r=r0, the ambiguity function can be approximately expressed as:

The distance and depth corresponding to the maximum value of the ambiguity function RD are the target distance and depth.

Step 4: Distance Estimation Cost Function

Similar to the matching field processing method, Equation (11) is used to estimate the position of the sound source, and multiple maxima appear in the r-z ambiguity plane. In order to better judge the real position, the normalized cost function |RD(r,z) | for:

In order to examine the accuracy of depth estimation at different distances, a distance cost function is defined:

in

Then the estimated distance is:

The optimal target position estimation result is:

(r _s ,z _s )=(r _max ,z _max (r _max )) (15)

Example 2: Simulation example

The simulation environment is Pekeris waveguide, the water body is uniform, the depth is 60m, the speed of sound is 1500m/s, and the density is 1.024g/cm ³ ; the seabed is a liquid semi-infinite space, the density is 1.7g/cm ³ , the speed of sound is 1650m/s, and the attenuation coefficient is 0.3 dB/λ. The frequency of the sound source is 1000 Hz, and it has a total of 15 normal waves of propagation modes. Set the target depth to 30m, the target to move at a uniform radial speed along the target-hydrophone connection line, the speed is v=5m/s, the vertical movement speed of the hydrophone is u=1m/s, and the initial distance is r ₀ =6km. The target moving speed search interval [0m/s, 10m/s], the interval is 0.5m/s. In order to prevent the occurrence of grating lobes, in the numerical integration of equation (2), the time step should satisfy vΔt < λ, that is, the horizontal spacing of the synthetic aperture is smaller than the wavelength of the acoustic wave. In this example, Δt = 0.1s. In general, the sampling time of experimental data is The interval is much less than 0.1s, which satisfies the condition of suppressing grating lobes.

Figure 5 is the result of the target radial motion velocity estimated by formula (5); Figure 6 is the result of the target distance-depth ambiguity function estimated by formula (11). The distance and depth corresponding to the maximum value are 6km and 30m, respectively.

In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in whole or in part in the form of a computer program product, the computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, all or part of the processes or functions described in accordance with the embodiments of the present invention are generated. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server, or data center Transmission to another website site, computer, server, or data center by wire (eg, coaxial cable, fiber optic, digital subscriber line (DSL), or wireless (eg, infrared, wireless, microwave, etc.)). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, or the like that contains one or more available mediums integrated. The usable media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, DVD), or semiconductor media (eg, Solid State Disk (SSD)), and the like.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art is within the technical scope disclosed by the present invention, and all within the spirit and principle of the present invention Any modifications, equivalent replacements and improvements made within the scope of the present invention should be included within the protection scope of the present invention.

Claims (10)

1. a single hydrophone vertical synthetic aperture passive positioning method, is characterized in that, described single hydrophone vertical synthetic aperture passive positioning method comprises: Build a single hydrophone synthetic vertical aperture strategy and sound field model; Define the velocity estimation cost function to estimate the radial velocity of the target; Define the distance-depth ambiguity function to estimate the target distance and depth; Define the cost function of distance estimation, improve the accuracy of target distance and depth estimation, and obtain the optimal target position. 2. The single hydrophone vertical synthetic aperture passive positioning method as claimed in claim 1, is characterized in that, described constructing single hydrophone synthetic vertical aperture strategy and sound field model, comprise: target is along with target and hydrophone. The horizontal connecting line makes a uniform motion in the direction of the angle θ, the speed is V, the radial motion speed v=Vcosθ, and the target radiates a simple harmonic signal with a circular frequency ω; the non-directional hydrophone moves uniformly in the depth direction, and the moving speed is u; the depth of the hydrophone at time 0 is z ₀ , and the depth H of the seabed moving at time T; taking the hydrophone at time 0 as the reference point, assuming that the unknown horizontal distance of the target is r ₀ , and the depth of the target is z _s , The approximate equivalent geometrically is that the target is stationary, the vertical motion speed of the hydrophone is u, and the horizontal motion speed is -v; If the marine environment information is known, the normal wave eigenwave number k _n and the eigenfunction Φ _n (z) are calculated, and the sound pressure analysis signal received by the hydrophone in the time t∈[0,T] is:

in,

If the moving target is used as the reference point, the movement trajectory of the hydrophone is synthesized into an inclined line array, the horizontal spacing of the array elements is ΔR=vcosθΔt, the vertical spacing is ΔZ=uΔt, and Δt is the vertical array synthesis sampling time; nth etc. The effective array element, that is, the signal received at the nth sampling time is:

3. The single-hydrophone vertical synthetic aperture passive positioning method as claimed in claim 2, wherein the acquisition method of the marine environment information is: a temperature and pressure sensor is attached during the laying down of the hydrophone, and the temperature profile and the hydrophone are measured. The actual depth of the listener at different times. 4. The method for passive positioning of a single hydrophone vertical synthetic aperture according to claim 1, wherein the estimation of the target radial motion speed comprises: a target moving speed interval v'∈[V ₁ ,V ₂ ], Taking exp(-ik _m v't) as the "steering" vector, and the eigenfunction Φ _m (z ₀ +ut) of the m-th normal wave as the weighting vector, do the following processing:

In the numerical integration, the time step should satisfy vΔt<λ, that is, the horizontal spacing of the synthetic aperture is smaller than the wavelength of the acoustic wave; without loss of generality, let z ₀ =0, uT = H, and H is the depth of the water body; According to the orthogonality of normal waves, when n=m, v'=v, |F _m | takes the maximum value; Define the cost function that determines the speed of the target movement:

The maximum value of the cost function corresponds to an estimate of the radial velocity of the target:

5. The single hydrophone vertical synthetic aperture passive positioning method of claim 1, wherein the defined distance-depth ambiguity function comprises: skill

Writing matrix form: F = MS; in, F=[F ₁ (v),F ₁ (v),...,F _N (v)] ^T ;

Then there are: S = M ^-1 F; The ambiguity function that defines the estimated target distance and depth (r-z) is:

Substitute the formula F=[F ₁ (v),F ₁ (v),...,F _N (v)] ^T into the formula

When r=r ₀ , the ambiguity function is approximately expressed as:

The distance and depth corresponding to the maximum value of the ambiguity function RD are the target distance and depth:

6. The single hydrophone vertical synthetic aperture passive positioning method as claimed in claim 1, wherein in step 4, the defined distance estimation cost function comprises: Similar to the matching field processing method, using the formula

To estimate the position of the sound source, multiple maxima appear in the rz ambiguity plane. In order to improve the accuracy of distance and depth estimation, the normalized cost function |RD(r,z)| is:

Define the distance cost function to examine the accuracy of depth estimation at different distances:

in,

Then the estimated distance is:

The optimal target position estimation result is: ( _rs , z _s )=(r _max , z _max (r _max )). 7 . A single hydrophone vertical synthetic aperture passive positioning system for implementing the single hydrophone vertical synthetic aperture passive positioning method according to any one of claims 1 to 6 , wherein the single hydrophone vertical synthetic aperture Aperture passive positioning systems include: Model building module for building a single hydrophone synthetic vertical aperture strategy and sound field model; The motion velocity estimation module is used to estimate the target radial motion velocity by defining the velocity estimation cost function; The target position estimation module is used to estimate the target distance and depth by defining the distance-depth ambiguity function; The target position estimation module is used to improve the target distance and depth estimation accuracy by defining the distance estimation cost function, and obtain the optimal target position estimation result. 8. A computer device, characterized in that the computer device comprises a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor is caused to perform the following steps: (1) Build a synthetic vertical aperture strategy and sound field model for a single hydrophone; (2) Define the speed estimation cost function to estimate the radial motion speed of the target; (3) Define the distance-depth ambiguity function to estimate the target distance and depth; (4) Define the cost function of distance estimation, improve the accuracy of target distance and depth estimation, and obtain the optimal target position. 9. A computer-readable storage medium storing a computer program, when the computer program is executed by a processor, the processor is caused to perform the following steps: (1) Build a synthetic vertical aperture strategy and sound field model for a single hydrophone; (2) Define the cost function of velocity estimation to estimate the radial velocity of the target; (3) Define the distance-depth ambiguity function to estimate the target distance and depth; (4) Define the cost function of distance estimation, improve the accuracy of target distance and depth estimation, and obtain the optimal target position. 10 . An information data processing terminal, wherein the information data processing terminal is used to implement the single hydrophone vertical synthetic aperture passive positioning system according to claim 7 .

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