An environment-adaptive passive sonar array element data real-time generation method

Abstract

The application provides an environment-adaptive passive sonar array element data real-time generation method, which can introduce target and receiving platform motion situation information in real time, obtain real-time marine environment data information, predict a sound field channel function by using a parabolic equation sound propagation model under a complex marine environment, and realizes real-time simulation generation of passive sonar array element data by using a multi-module step-by-step parallel calculation strategy, and has the advantages of real-time calculation, high-precision calculation, strong universality, strong scalability, good environmental applicability and the like, and has a relatively broad application prospect in underwater acoustic countermeasures, simulation deduction and auxiliary decision-making.

Description

A method for real-time generation of metadata for an environment-adaptive passive sonar array Technical Field

[0001] This invention relates to the field of sonar array element domain data processing, and mainly to a method for real-time generation of environmentally adaptive passive sonar array element data. Background Technology

[0002] Acquiring actual sonar array element-domain data is difficult, requiring significant human and material resources, and the resulting data samples are limited, failing to meet the needs of practical sonar design and performance verification. Therefore, a passive sonar array element-domain data simulation generation technique is proposed. The purpose of passive sonar array element-domain data simulation is to address the challenge of limited measured sonar array element-domain data samples through simulation, while simultaneously achieving data sample generalization under different environments and conditions, supporting the performance verification of sonar signal processing technology and the design and optimization of novel sonars.

[0003] The current passive sonar array element-domain data simulation technology mainly uses a serial structure, including the following steps: First, setting the motion state information of the receiving array platform and the target; second, setting the radiated noise parameters of the underwater target and generating the target radiated noise time-domain waveform data; third, setting the parameters of the passive sonar receiving array; fourth, calculating the relative positional relationship between the target and each array element of the receiving platform based on the motion state of the receiving array and the target, and the receiving array parameters; fifth, generating the sound field channel function time-domain waveform on each array element using a normal mode model based on the positional relationship; sixth, generating the received signal in the receiving array element domain by using the target radiated noise time-domain waveform and the sound field channel function time-domain waveform through convolution operation; seventh, setting the marine environmental noise parameters and generating the marine environmental background noise time-domain signal for each array element; eighth, summing the received signal with the background noise to finally generate the passive sonar array element-domain simulation data.

[0004] Current methods for generating passive sonar array metadata have several problems in practical engineering applications, mainly in the following aspects: First, it is difficult to generate data based on the real-time motion status information of the target and the receiving platform; second, the underwater acoustic propagation models used cannot quickly or even in real-time predict the sound field signal function in a distance-independent marine environment; third, the data simulation process usually does not effectively utilize the marine environment database, resulting in prediction results that cannot match the environment; fourth, problems with the data generation process and architecture prevent real-time data generation. To address these issues, this invention proposes a novel real-time, high-precision method for generating passive sonar array metadata, solving problems such as real-time acquisition of arbitrary motion status, real-time acquisition and response of marine environmental data, rapid calculation of the sound field under varying distance conditions, and real-time generation of array metadata. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a method for real-time generation of metadata for an environment-adaptive passive sonar array.

[0006] The objective of this invention is achieved through the following technical solution: A method for real-time generation of passive sonar array metadata that is environmentally adaptive. This method involves real-time induction of target and receiving platform motion status information, acquisition of real-time marine environmental data, prediction of the sound field channel function using a parabolic equation sound propagation model in complex marine environments, and real-time simulation generation of passive sonar array metadata through a multi-module, step-by-step parallel computing strategy. The specific steps are as follows:

[0007] Step 1: Receive the platform's motion status and receive the sonar platform's latitude and longitude (LonB, LatB) and speed V in real time. B Heading D B and water depth Z B The time interval is ΔT;

[0008] Step 2: Target motion status acquisition, real-time reception of the target's latitude and longitude (LonT, LatT) and water entry depth ZT, with a time interval of ΔT;

[0009] Step 3: Setting sonar operating parameters, including setting the sonar operating frequency band (FL, FH), sampling frequency Fs, and spatial coordinates of the sonar receiving array elements (X(1:N), Y(1:N), Z(1:N)), where N is the number of array elements, X is due north, Y is due east, and Z is the depth direction.

[0010] Step 4: Motion parameter topology solution, calculate the horizontal distance R(k△T,1:N) between the target and each element of the receiving array at different times, where k represents the time sequence number;

[0011] Step 5: Set the marine environmental parameters required for underwater channel function calculation, including sound velocity profile, seabed topography, and seabed sediment parameters;

[0012] Step 6: Calculate the underwater channel function using the parabolic equation underwater acoustic propagation model to generate the channel function of the target radiated noise reaching each receiving array element under the target's motion state;

[0013] Step 7: Set the target radiated noise parameters, including the continuous spectrum, line spectrum, and modulation spectrum parameters of the radiated noise, as inputs for generating the target radiated noise signal;

[0014] Step 8: Target radiation noise signal generation;

[0015] Step 9: Sonar target signal generation, which generates the signal received by each element of the receiving array after the target radiated noise propagates through the underwater acoustic channel;

[0016] Step 10: Generation of sonar array element domain data.

[0017] Furthermore, in step 4, using the latitude and longitude of the receiving platform (LonB(k△T), LatB(k△T)) and the latitude and longitude of the target (LonT(k△T), LatT(k△T)), the distance coordinates (X) of the target relative to the platform are calculated using the Earth coordinate system. TD (k△T),Y TD (k△T)); Based on the receiving platform's heading and the array element's spatial coordinates, the coordinates of each array element relative to the array center under actual conditions are calculated as follows:

[0018]

[0019] The horizontal distance between the target and the array element is:

[0020]

[0021] Furthermore, step 6 specifically includes the following steps:

[0022] Based on the time interval, the frequency sampling interval of the broadband channel function The number of frequencies used in the sound field calculation is: Using the sound velocity profile at time 1, seabed topography, and seabed sediment parameters, the sound field at different frequencies is rapidly obtained through parallel computation using a parabolic equation model sound field calculation formula.

[0023]

[0024] Where p(r) is the sound pressure at a distance r, Δr is the recursive distance, and L p Let a and b be the order of the Padé approximation, respectively, and k0 be the reference wavenumber.

[0025] The frequency domain expression of the channel function is:

[0026] P(FL:△f:FH,r)=[p(FL,r),p(FL+△f,r),...,p(FH-△f,r),p(FH,r)]

[0027] Based on the horizontal distance R(△T:△T:M△T,1:N) between the target and the array elements, the frequency domain channel function P for different array elements at different times is obtained. A (FL:△f:FH,△T:△T:M△T,1:N):

[0028] P A(FL:△f:FH,△T:△T:M△T,1:N)=P(FL:△f:FH,R(△T:△T:M△T,1:N))

[0029] The time-domain channel function with a duration of 2ΔT is obtained using the inverse Fourier transform:

[0030] ht(0:1 / Fs:(2△T-1 / Fs),△T:△T:M△T,1:N)=FFT -1 (P A (FL:△f:FH,△T:△T:M△T,1:N)).

[0031] Furthermore, in step 8, a target radiated noise signal is generated. Based on the set spectral parameters, the expression for the radiated noise signal is:

[0032]

[0033] In the formula, represents the line spectrum components of the ship's radiated noise; n(0:1 / Fs:(△T-1 / Fs)) represents random noise; For the modulation components of ship radiated noise, n cav (0:1 / Fs:(△T-1 / Fs)) represents a continuous spectrum signal;

[0034] Using a 50% time overlap calculation ensures the phase continuity of the simulated signal. The radiated noise signal, after being supplemented with ΔT time overlap, is as follows:

[0035] St(0:1 / Fs:(2△T-1 / Fs))=[S(0:1 / Fs:(△T-1 / Fs))0*(1:△T*Fs)].

[0036] Furthermore, step 9 includes the following steps:

[0037] The first target signal received by each array element is obtained by convolving the target radiated noise with the channel function:

[0038] R △T (0:1 / Fs:(2△T-1 / Fs),1:N)

[0039] =St(0:1 / Fs:(2△T-1 / Fs))·ht(0:1 / Fs:(2△T-1 / Fs),△T,1:N)

[0040] The target signal in the second time period is:

[0041] R 2△T (△T+0:1 / Fs:(2△T-1 / Fs),1:N)

[0042] =St(△T+0:1 / Fs:(2△T-1 / Fs))·ht(0:1 / Fs:(2△T-1 / Fs),2△T,1:N)

[0043] The target signal in the Mth time period is:

[0044] R M△T ((M-1)△T+0:1 / Fs:(2△T-1 / Fs),1:N)

[0045] =St((M-1)△T+0:1 / Fs:(2△T-1 / Fs))·ht(0:1 / Fs:(2△T-1 / Fs),M△T,1:N)

[0046] Where <·> represents convolution operation;

[0047] Finally, the target signal Rt received by each array element is obtained by summing the signals at different time intervals.

[0048] Furthermore, step 10 includes the following steps: adding a noise signal to the target signal to obtain sonar array element domain data Ra under any situation:

[0049] Ra(0:1 / Fs:(t*Fs-1))=Rt(0:1 / Fs:(t*Fs-1))+Nt(0:1 / Fs:(t*Fs-1)).

[0050] Furthermore, the different steps described above are processed in a time-division parallel manner to achieve real-time generation of passive sonar array metadata.

[0051] The beneficial effects of this invention are as follows:

[0052] Current passive sonar array element-domain data simulation technology cannot meet the requirements of real-time computing. Limited accuracy in channel function calculation and the inability to set the target and platform motion states in real time prevent passive sonar array data simulators from playing a significant role in practical engineering applications. This invention aims to propose a real-time generation method for passive sonar array element data based on a parabolic equation model. This method simultaneously possesses functions such as real-time computing, accurate prediction, and rapid parameter response, accelerating the application and transformation of simulation technology in engineering. The method mainly addresses the following problems:

[0053] (1) Solving the problem of high-precision generation of passive sonar array metadata. The method of this invention uses a parabolic equation model instead of an environment-independent sound field prediction model (plane wave, cylindrical wave or spherical wave attenuation model) to calculate the channel function of the underwater sound field, thereby improving the accuracy of passive sonar array metadata simulation.

[0054] (2) Solving the problem of matching passive sonar array element domain data with the actual environment. The method of the present invention fully considers the actual marine environment data. When calculating the sound field, actual marine environment parameters, seabed topography, seabed sediment parameters, etc. can be used, which improves the environmental applicability of the data simulation.

[0055] (3) Solving the problem of real-time generation of passive sonar array element domain data. The method of this invention utilizes methods such as parallel acoustic field computing and multi-module synchronous computing to achieve rapid and real-time prediction of passive sonar array element domain data simulation. It can quickly generate massive amounts of simulation data to support sonar array design and sonar signal processing method verification.

[0056] (4) Solving the problem of sonar array metadata generation under arbitrary motion states of the target and platform. The method of the present invention adopts a multi-module time-division asynchronous design, which can realize the real-time generation of passive sonar array metadata of the target and receiving platform under arbitrary motion states, and enable real-time setting and rapid response of motion parameters during simulation. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art or ordinary skills, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 is a flowchart of the passive sonar array metadata simulation process.

[0059] Figure 2 is a timing diagram of the passive sonar array metadata simulation. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0061] This invention proposes a real-time method for generating passive sonar array metadata that is environmentally adaptive. This method can acquire real-time marine environmental data by incorporating motion status information from the target and receiving platform, using a parabolic acoustic propagation model in complex marine environments to predict the acoustic field channel function, and employing a multi-module, step-by-step parallel computing strategy to achieve real-time simulation and generation of passive sonar array metadata. The data simulation process consists of 10 steps, and the flowchart is shown in Figure 1. The functions and implementation methods of each step are described below.

[0062] Step 1: Receiving platform motion status signal

[0063] Responsible for receiving real-time latitude and longitude (LonB, LatB) and speed V from the sonar platform. B Heading D B and water depth Z B The time interval is △T.

[0064] Step 2: Target motion status introduction

[0065] It is responsible for receiving the target's latitude and longitude (LonT, LatT) and water depth ZT in real time, with a time interval of ΔT.

[0066] Step 3: Setting Sonar Operating Parameters

[0067] Responsible for setting the sonar's operating frequency band (FL, FH), sampling frequency Fs, and spatial coordinates of the sonar receiving array elements (X(1:N), Y(1:N), Z(1:N)), where N is the number of elements, X is due north, Y is due east, and Z is the depth direction.

[0068] Step 4: Topology calculation of motion parameters

[0069] It is responsible for calculating the horizontal distance R(k△T,1:N) between the target and each element of the receiving array at different times, where k represents the time sequence number.

[0070] Using the latitude and longitude of the receiving platform (LonB(k△T), LatB(k△T)) and the latitude and longitude of the target (LonT(k△T), LatT(k△T)), the distance coordinates (X) of the target relative to the platform can be calculated using the Earth coordinate system. TD (k△T),Y TD (k△T)). Based on the receiving platform's heading and the array element spatial coordinates, the coordinates of each array element relative to the array center under actual conditions can be calculated as follows:

[0071]

[0072] Therefore, the horizontal distance between the target and the array element is:

[0073]

[0074] Step 5: Setting marine environmental parameters

[0075] It is responsible for setting the sound velocity profile, seabed topography, and seabed sediment parameters required for underwater channel calculations. With the support of a marine environmental database, it can quickly generate three types of data adaptively using the latitude and longitude (LonB(k△T), LatB(k△T)) and (LonT(k△T), LatT(k△T)) of the target and receiving platform.

[0076] Step 6: Underwater Channel Function Calculation

[0077] This function is responsible for generating the channel function for the target radiated noise arriving at each receiving array element under the target's motion state. To ensure the fidelity and environmental adaptability of the channel function, a parabolic underwater acoustic propagation model is adopted instead of the commonly used normal mode wave model or ray model to improve the accuracy and speed of sound field calculation in complex marine environments.

[0078] Calculating the broadband channel function using a parabolic model still requires a certain amount of computation time, which cannot be completed within the time interval ΔT. Let's assume the required time is T = MΔT. Therefore, to ensure that the passive sonar array metadata simulation meets real-time requirements, the following approximation method is used for the sound field calculation: within time T, the terrain changes slowly between the target and the receiving platform, so uniform seabed topography parameters and marine environmental parameters can be used.

[0079] Based on the time interval, the frequency sampling interval of the broadband channel function The number of frequencies used in the sound field calculation is: Using the sound velocity profile at time 1, seabed topography, and seabed sediment parameters, and employing the parabolic equation model sound field calculation formula, the sound field at different frequencies can be quickly obtained through parallel computation.

[0080]

[0081] Where p(r) is the sound pressure at a distance r, Δr is the recursive distance, and L p Let be the order of the Padé approximation, a and b be the coefficients of the Padé approximation, and k0 be the reference wavenumber.

[0082] The frequency domain expression of the channel function is:

[0083] P(FL:△f:FH,r)=[p(FL,r),p(FL+△f,r),...,p(FH-△f,r),p(FH,r)]

[0084] Based on the horizontal distance R(△T:△T:M△T,1:N) between the target and the array elements, the frequency domain channel function P for different array elements at different times can be obtained. A (FL:△f:FH,△T:△T:M△T,1:N):

[0085] PA (FL:△f:FH,△T:△T:M△T,1:N)=P(FL:△f:FH,R(△T:△T:M△T,1:N))

[0086] The time-domain channel function with a duration of 2ΔT can be obtained using the inverse Fourier transform:

[0087] ht(0:1 / Fs:(2△T-1 / Fs),△T:△T:M△T,1:N)=FFT -1 (P A (FL:△f:FH,△T:△T:M△T,1:N))

[0088] Step 7: Target Radiated Noise Parameter Settings

[0089] It is responsible for setting the continuous spectrum, line spectrum, and modulation spectrum parameters of the radiated noise as inputs for generating the target radiated noise signal.

[0090] Step 8: Target Radiated Noise Signal Generation

[0091] Responsible for generating the target radiated noise signal. Based on the set spectral parameters, the expression of the radiated noise signal is:

[0092]

[0093] In the formula, represents the line spectrum components of the ship's radiated noise; n(0:1 / Fs:(△T-1 / Fs)) represents random noise; For the modulation components of ship radiated noise, n cav (0:1 / Fs:(△T-1 / Fs)) is a continuous spectrum signal.

[0094] To maintain the phase continuity of the simulated signal, a 50% time overlap is used in the calculation. The radiated noise signal, after being supplemented with ΔT time overlap, is as follows:

[0095] St(0:1 / Fs:(2△T-1 / Fs))=[S(0:1 / Fs:(△T-1 / Fs))0*(1:△T*Fs)]

[0096] Step 9: Sonar target signal generation

[0097] This is responsible for generating the signals received by each element of the receiving array after the target radiated noise propagates through the underwater acoustic channel. The first target signal received by each element can be obtained by convolving the target radiated noise with the channel function:

[0098] R △T (0:1 / Fs:(2△T-1 / Fs),1:N)

[0099] =St(0:1 / Fs:(2△T-1 / Fs))·ht(0:1 / Fs:(2△T-1 / Fs),△T,1:N)

[0100] The target signal in the second time period is:

[0101] R 2△T (△T+0:1 / Fs:(2△T-1 / Fs),1:N)

[0102] =St(△T+0:1 / Fs:(2△T-1 / Fs))·ht(0:1 / Fs:(2△T-1 / Fs),2△T,1:N)

[0103] The target signal in the Mth time period is:

[0104] R M△T ((M-1)△T+0:1 / Fs:(2△T-1 / Fs),1:N)

[0105] =St((M-1)△T+0:1 / Fs:(2△T-1 / Fs))·ht(0:1 / Fs:(2△T-1 / Fs),M△T,1:N)

[0106] In this context, <·> represents the convolution operation.

[0107] The final target signal Rt received by each array element is obtained by summing the signals over different time periods, i.e.:

[0108] Rt(0:1 / Fs:(△T-1 / Fs),1:N)=R △T (0:1 / Fs:(△T-1 / Fs),1:N)

[0109] Rt(△T+(0:1 / Fs:(△T-1 / Fs)),1:N)=R △T (△T+(0:1 / Fs:(△T-1 / Fs)),1:N)+R 2△T (0:1 / Fs:(△T-1 / Fs),1:N)

[0110] Rt(2△T+(0:1 / Fs:(△T-1 / Fs)),1:N)=R 2△T (△T+(0:1 / Fs:(△T-1 / Fs)),1:N)+R 3△T (0:1 / Fs:(△T-1 / Fs),1:N)

[0111] ...

[0112] Rt((M-1)△T+(0:1 / Fs:(△T-1 / Fs)),1:N)=R (M-1)△T(△T+(0:1 / Fs:(△T-1 / Fs)),1:N)+R M△T (0:1 / Fs:(△T-1 / Fs),1:N)

[0113] Rt(M△T+(0:1 / Fs:(△T-1 / Fs)),1:N)=R M△T (△T+(0:1 / Fs:(△T-1 / Fs)),1:N)+R (M+1)△T (0:1 / Fs:(△T-1 / Fs),1:N)

[0114] ...

[0115] Step 10: Generation of sonar array element domain data

[0116] This is responsible for generating passive sonar array element-domain data. By adding a noise signal to the target signal mentioned above, sonar array element-domain data Ra under any situation can be obtained:

[0117] Ra(0:1 / Fs:(t*Fs-1))=Rt(0:1 / Fs:(t*Fs-1))+Nt(0:1 / Fs:(t*Fs-1))

[0118] To achieve real-time generation of passive sonar array metadata, different steps are processed in parallel with time-division multiplexing. Figure 2 shows the simulation timing diagram of passive sonar array metadata. Label 1 represents the receiving platform motion situation initiation, label 2 represents the target motion situation initiation, label 3 represents sonar operating parameter settings, label 4 represents motion parameter topology calculation, label 5 represents marine environment parameter settings, label 6 represents target radiated noise parameter settings, label 7 represents target radiated noise signal generation, label 8 represents underwater channel function calculation, label 9 represents sonar target signal generation, and label 10 represents sonar array metadata generation. As can be seen from the timing diagram, the time period from 0 to 3T is the data simulation setup process, where 0 to T is the situation initiation stage, T to 2T is the situation calculation and radiated noise generation or initiation stage, and 2T to 3T is the channel calculation and array metadata generation stage. After a 3T preparation period (typically on the order of seconds), the real-time data simulation output stage begins, where all modules can run in real time, ultimately achieving real-time generation of passive sonar array metadata under arbitrary situations and complex marine environments.

[0119] The core technology of this invention lies in the proposal of a method for real-time generation of passive sonar array metadata under arbitrary situations and actual marine environments. This method can simultaneously meet the functions of real-time target acquisition and receiving platform arbitrary motion states, rapid parallel calculation of channel functions using parabolic equation models under actual marine environments, and real-time generation of array metadata, and has significant engineering application value.

[0120] (1) The new method can import motion situation information in real time. The situation can be set and changed in real time during the simulation process, which can better adapt to the real-time battlefield environment.

[0121] (2) The new method can use the real-time location information to obtain sound velocity profiles, seabed topography and seabed sediment parameters from the marine environment database during the simulation process, thereby improving the realism and environmental adaptability of the simulation.

[0122] (3) The new method uses a parabolic equation model instead of the attenuation model, normal mode model and ray model, which can improve the flexibility and accuracy of underwater channel function prediction.

[0123] (4) The new method proposes a real-time generation architecture for passive sonar array metadata, which adopts a step-by-step parallel strategy. This can compress the real-time computing response time to the second level and achieve rapid response of motion parameters, thus solving a key problem for the engineering transformation and application of data simulation.

[0124] The present invention proposes a real-time generation method for passive sonar array metadata, which can introduce or set the motion status of the target and receiving platform in real time. During the simulation process, relevant simulation parameters can be changed at any time. It adopts actual marine environmental data and high-precision underwater acoustic propagation models in complex environments. It has the advantages of real-time calculation, high-precision calculation, strong versatility, strong scalability, and good environmental applicability. It has broad application prospects in underwater acoustic countermeasures, simulation and deduction, and decision support.

[0125] Glossary of relevant technical terms

[0126] Step-by-step parallelism: In the real-time simulation of passive sonar, some of the 10 steps are sequential, while others are computed in parallel on different computer threads.

[0127] Environmental Adaptation: During the simulation, actual marine environmental parameters can be read based on the motion status to generate high-precision signal function prediction results.

[0128] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for real-time generation of metadata for an environment-adaptive passive sonar array, characterized in that: Real-time acquisition of target and receiving platform motion status information, obtaining real-time marine environmental data, predicting sound field channel functions using a parabolic equation sound propagation model in complex marine environments, and achieving real-time simulation generation of passive sonar array metadata through a multi-module, step-by-step parallel computing strategy. The specific steps are as follows: Step 1: Acquiring the receiving platform's motion status, receiving the latitude and longitude of the sonar platform in real time. Speed ​​V B Heading D B and water depth Z B Step 2: Target motion status acquisition, real-time reception of the target's latitude and longitude (LonT, LatT) and water depth ZT, with a time interval of ∆T; Step 3: Sonar operating parameter settings, including setting the sonar operating frequency band (FL, FH), sampling frequency Fs, and spatial coordinates of the sonar receiving array elements. Where N is the number of array elements, X is due north, Y is due east, and Z is the depth direction; Step 4: Motion parameter topology solution, calculate the horizontal distance between the target and each array element of the receiving array at different times. , where k represents the time sequence number; Step 5, set the marine environmental parameters required for underwater channel function calculation, including sound velocity profile, seabed topography, and seabed sediment parameters; Step 6, use the parabolic equation underwater acoustic propagation model to calculate the underwater channel function and generate the channel function of the target radiated noise reaching each receiving array element under the target motion state; Step 7, set the target radiated noise parameters, setting the continuous spectrum, line spectrum, and modulation spectrum parameters of the radiated noise as inputs for generating the target radiated noise signal; Step 8: Target radiation noise signal generation; Step 9: Sonar target signal generation, generating the signal received on each element of the receiving array after the target radiated noise propagates through the underwater acoustic channel; Step 10: Sonar array data generation; In step 4, the latitude and longitude of the receiving platform are used. and the latitude and longitude of the target The distance coordinates of the target relative to the platform are calculated using the Earth coordinate system. Based on the receiving platform's heading and the array element's spatial coordinates, the coordinates of each array element relative to the array center under actual conditions are calculated as follows: The horizontal distance between the target and the array element is: In step 6, the specific steps are as follows: Based on the time interval, the broadband channel function frequency sampling interval... The number of frequencies for sound field calculation is: Using the sound velocity profile at the first time point, seabed topography, and seabed sediment parameters, the sound field at different frequencies is quickly obtained through parallel computation using the parabolic equation model sound field calculation formula. in, For the recursive distance, The order of the Padé approximation. The coefficients are those used in the Padé approximation. The reference wavenumber is used; the frequency domain expression of the channel function is: Based on the horizontal distance between the target and the array elements, the frequency domain channel function of different array elements at different times is obtained. ： The duration was obtained using the inverse Fourier transform. Time-domain channel function: In step 8, a target radiated noise signal is generated. Based on the set spectral parameters, the expression for the radiated noise signal is: In the formula, The components of the radiated noise line spectrum of the ship; It is random noise; For the modulation components of ship radiated noise, The signal is a continuous spectrum signal; a 50% time overlap is used for calculation to maintain the phase continuity of the simulated signal, and radiated noise signal is supplemented. The signal after time overlap is: Step 9 includes the following steps: The first target signal received by each array element is obtained by convolving the target radiated noise with the channel function: The target signal in the second time period is: The target signal in the Mth time period is: in, This represents a convolution operation; the final target signal received by each array element is obtained by summing signals from different time periods; step 10 includes the following steps: adding a noise signal to the above target signal to obtain sonar array data under any situation. ： 。 2. The method for real-time generation of environmentally adaptive passive sonar array metadata according to claim 1, characterized in that: The different steps described above are processed in a time-division parallel manner to achieve real-time generation of passive sonar array metadata.

Images