Large-depth hydrophone amplitude response measurement method based on deep sea environment noise field depth distribution

Abstract

The invention discloses a large-depth hydrophone amplitude response measurement method based on deep sea environment noise field depth distribution, and the method comprises the steps: receiving a field measurement result of a noise spectrum level through matching a calibrated hydrophone or a standard hydrophone under low pressure, and carrying out the measurement of the amplitude response of a large-depth hydrophone based on a noise field modeling result of a marine environment parameter and a sound field model in a measurement period; the noise field full-depth distribution rule of the tested sea area is obtained, then the difference value between the noise field full-depth distribution rule and the actual measurement result of the hydrophone to be tested is calculated, the difference value is compensated to the amplitude response nominal value of the hydrophone to be tested, and the amplitude response of the hydrophone to be tested in the large-depth environment can be obtained. The invention provides a new way for obtaining the sensitivity of the hydrophone in a deep-sea large-depth environment.

Description

Technical Field

[0001] The invention belongs to the field of measurement technology, and in particular relates to a method for measuring amplitude response of a deep-sea hydrophone based on the depth distribution of a deep-sea environmental noise field. Background Art

[0002] As the working frequency of underwater acoustic communication and underwater acoustic detection equipment gradually develops towards the low-frequency field and deep sea, it is urgent to establish low-frequency underwater acoustic measurement standard equipment and test methods under high hydrostatic pressure to solve the laboratory or field measurement problem of hydrophone amplitude response under high hydrostatic pressure. For normal pressure conditions, "Low-frequency Calibration Method for Acoustic Hydrophone (GB / T 4130-2000)" proposes a primary calibration method (including coupled cavity reciprocity method, piezoelectric compensation method, and vibrating liquid column method) and a secondary calibration method (closed cavity comparison method and piston sounder calibration method) for hydrophone sensitivity in the 1Hz-3.15kHz frequency band. The vibrating liquid column method is a method of determining the sound pressure sensitivity of the hydrophone by measuring the vibration acceleration. This method is used by the national military; the coupled cavity and vibrating liquid column method test equipment is generally not large, has certain requirements on the transducer size, and cannot measure multiple transducers at the same time, and has low efficiency. Acoustic Transducer Measurement (GB / T 7965-2002) proposes free-field sensitivity measurement methods including reciprocity method and comparison method, which realizes sensitivity measurement in the mid-high frequency band; the secondary calibration of hydrophone includes two methods: comparison between the calibrated hydrophone and the standard hydrophone and comparison between the calibrated hydrophone and the standard transmitter. The former method is usually used, while the latter method is rarely used. The comparison method needs to meet the free-field conditions. In addition, the reverberation sound field method mainly forms a reverberation area with relatively stable sound energy in a limited space for testing. In practice, due to reasons such as the sound field volume and reflection, the ideal reverberation sound field conditions cannot be met. Although spatial averaging can eliminate certain reverberation sound field inhomogeneities from the measurement, the current research and construction of reverberation water tanks is immature and has not yet reached the practical stage. Under high hydrostatic pressure, the static capacitance of the hydrophone piezoelectric element will change significantly, which has a great impact on the receiving sensitivity. Under the conditions of 10MPa high hydrostatic pressure and 2-200kHz frequency band, according to the spherical wave reciprocity principle, by measuring the transfer impedance between the transmitting transducer, the reciprocal transducer and the receiving hydrophone, a standard hydrophone free-field sensitivity calibration system based on a high-pressure anechoic water tank has been established. However, there is currently no effective measurement method for measuring the sensitivity of hydrophones under higher hydrostatic pressures above 10MPa, and for measuring the sensitivity of hydrophones in the low frequency band below 2kHz under 10Mpa high hydrostatic pressure. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the present invention provides a method for measuring the amplitude response of a deep-sea hydrophone based on the depth distribution of the deep-sea environmental noise field. By matching the field measurement results of the noise spectrum level received by a calibrated hydrophone or a standard hydrophone under low pressure, and the noise field modeling results based on the ocean environmental parameters and the sound field model during the measurement, the full-depth distribution law of the noise field in the test sea area is obtained, and then the difference between the actual measurement result of the hydrophone to be tested is calculated, and the difference is compensated to the nominal value of the amplitude response of the hydrophone to be tested, so that the amplitude response of the hydrophone to be tested in a deep-sea deep environment can be obtained. The present invention provides a new way to obtain the sensitivity of hydrophones in deep-sea deep environments.

[0004] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0005] Step 1: In the selected test sea area, deploy the deep-depth hydrophones to be tested in the form of vertical linear arrays or distributed arrays, and use pressure sensors to record the deployment depth information of the hydrophones to be tested. Different frequencies f of the hydrophone to be tested k The nominal sensitivity is M0(f k ); Q represents the number of hydrophones, and q represents the serial number of hydrophones at different depths;

[0006] Within 1000 meters underwater, at a certain depth, deploy two or more standard hydrophones or calibrated hydrophones, whose amplitude response is M B (f k );

[0007] Step 2: After the measurement system is deployed, the experimental ship moves away from the measurement system and shuts down the main engine of the experimental ship to eliminate the influence of the experimental ship;

[0008] The standard hydrophone or calibrated hydrophone and the hydrophone to be tested continuously record the ocean ambient noise with a sampling rate of f s Greater than twice the upper limit of the measurement frequency band; synchronously measure other marine environmental parameters such as sound velocity profile data SSP, wind speed and seabed bottom characteristics during the experiment; after recovering the measurement system, use the power spectrum estimation method to calculate the measured marine environmental spectrum level NL averaged over one-third octave bandwidth exp ;

[0009] Step 3: For the ship noise source, based on the Automatic Ship Identification System AIS satellite data or the Voluntary Ship System VOS database, the space is divided into grids to obtain the distribution density d of different types of ships. S ; Then, based on the empirical formula of radiation source level of different types of ship radiation noise sources, the ship radiation noise source level NSL per unit area of ​​space is obtained ship (f k ,st);

[0010] For wind noise sources, based on the NCEP database of the National Center for Environmental Prediction or the wind speed v of the National Marine Environmental Prediction Center wind Real-time data or reanalysis data are divided into grids in space to obtain the spatial distribution of wind speed. Then, based on the empirical formula of wind noise source level, the wind noise source level NSL per unit area of ​​space is obtained. wind (f k ,v wind );

[0011] The intensity of the monopole noise source per unit area is expressed as

[0012] Step 4: Test the seabed topography and sound velocity profile of the ocean environment parameters. Based on the principle of acoustic field reciprocity, use the parabolic equation or ray method to establish a noise field numerical calculation model, superimpose the contribution of ship noise sources and wind noise sources to the total noise field, and obtain the vertical distribution characteristics of the deep-sea environmental noise spectrum level NL simu (z r ,f k ), calculate the one-third octave bandwidth average f k The simulated ocean environment spectrum level NL simu ;z r It means that the pressure sensor is used to record the deployment depth information of the hydrophone to be tested;

[0013] Step 5: After eliminating the discrete interference in the noise data, a snapshot time period t i In the receiving depth-frequency two-dimensional plane, a simulated ocean environmental noise spectrum level matrix based on sound field calculation is constructed. Measured noise spectral level matrix based on calibrated hydrophones, hydrophones under test and sea trial data Analyze multiple snapshots (L1, L2, ..., L N ) ocean noise data, and after making the measured matrix of the calibrated hydrophone and the simulation matrix consistent or with the minimum error, the vertical distribution characteristic NL simu (z r ,f k ) as the standard, and obtain the mean square error between the noise spectrum matrix of the hydrophone to be tested and the simulation noise spectrum matrix where e i (z r ,f k )=NL simu (z r ,f k )-NL exp (z r ,f k ), e 12 Compensate to the nominal sensitivity of the hydrophone to obtain the actual sensitivity of the hydrophone Get the corresponding snapshot time (t1, t2, ..., t N ) The amplitude response of the hydrophone to be tested (M1, M2, …, M N ), find its mean M=(M1+M2+…+M N ) / N to reduce the error, and the mean value M is the final amplitude response of the hydrophone to be tested.

[0014] Preferably, the vertical distribution characteristic of the ambient noise spectrum level refers to the variation law of the noise spectrum level from the sea surface to the seabed, that is, different hydrostatic pressures.

[0015] A computer program, wherein the computer program enables a computer to execute the above method for measuring the amplitude response of a deep-depth hydrophone.

[0016] An electronic device, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device executes the above-mentioned large depth hydrophone amplitude response measurement method

[0017] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for measuring the amplitude response of a deep-depth hydrophone.

[0018] A chip comprises: a processor, which is used to call and run a computer program from a memory, so that a device equipped with the chip executes the above-mentioned large-depth hydrophone amplitude response measurement method.

[0019] A computer program product, comprising a computer storage medium storing a computer program, wherein the computer program comprises instructions executable by at least one processor, and when the instructions are executed by the at least one processor, the above-mentioned method for measuring the amplitude response of a deep-depth hydrophone is implemented.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1) Under high hydrostatic pressure conditions, especially high hydrostatic pressure greater than 10MPa, accurate measurement of deep-sea hydrophone sensitivity at great depths is achieved; 2) The requirements for the hydrophone's external dimensions are low, and simultaneous measurement of multiple hydrophones or simultaneous measurement under different pressures can be achieved, and its measurement efficiency is relatively high; 3) The measurement method covers a wide frequency band, and basically achieves the measurement of hydrophone sensitivity in the commonly used frequency bands of hydrophones (including low frequency bands); 4) The measurement method utilizes the ocean background field, does not require the emission of sound source equipment or vibration test platforms, and can simultaneously implement other active hydroacoustic tests and hydrophone amplitude response measurements, does not require equipment calibration before the test, and has high utilization rates of test facilities and time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the overall flow chart of the amplitude response measurement of the deep-depth hydrophone of the present invention;

[0023] Figure 2 Schematic diagram of the distribution of marine environmental parameters and noise sources according to an embodiment of the present invention, (a) sound velocity profile and anchor structure, (b) seabed topography, (c) wind noise source, (d) ship noise source;

[0024] Figure 3 The receiving noise spectrum levels of the calibrated hydrophone (receiving depth 708m) and the hydrophone to be tested (receiving depth 718m) according to the embodiment of the present invention, (a) the receiving noise spectrum level of the calibrated hydrophone, (b) the receiving noise spectrum level of the hydrophone to be tested;

[0025] Figure 4 Schematic diagram of noise field modeling and theoretical law of noise spectrum level depth distribution (125Hz, 400Hz and 800Hz) according to an embodiment of the present invention, (a) schematic diagram of noise field modeling, (b) noise field depth distribution characteristics;

[0026] Figure 5 is the sensitivity change value of the hydrophone to be tested in the embodiment of the present invention (nominal value -190dB, the thick dotted line is its mean value);

[0027] Figure 6 The noise spectrum level after the amplitude response compensation of the hydrophone to be tested in Example 8 of the present invention (receiving depth 3718m);

[0028] Figure 7 The nominal and measured values ​​of the amplitude response of the hydrophone under test in Example 8 of the present invention are the propagation loss results (100 Hz), (a) SD = 50 m, nominal sensitivity; (b) SD = 50 m, measured value; (c) SD = 300 m, nominal sensitivity; (d) SD = 300 m, measured value;

[0029] Figure 8 Comparison of propagation losses at different frequencies obtained by the nominal and measured values ​​of the amplitude response of the 8# deep-depth hydrophone to be tested in the present invention; (a) SD = 50m, nominal value, (b) SD = 50m, measured value, (c) SD = 300m, nominal value, (d) SD = 300m, measured value. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0031] The present invention proposes a method for measuring the amplitude response / sensitivity of a deep-sea hydrophone of deep-sea environmental noise depth distribution. The method obtains the theoretical law of the depth distribution of the ocean noise field in the test sea area by constructing the field measurement value of the noise spectrum level received by a calibrated hydrophone or a standard hydrophone under low pressure and the matching objective function between the ocean environmental parameters during the measurement and the noise field modeling value of the sound field model. The difference between the measured value of the hydrophone to be tested and the theoretical law is calculated and compensated to the nominal value of the amplitude response of the hydrophone to be tested, thereby realizing the amplitude response measurement of the hydrophone to be tested in highly static water.

[0032] A method for measuring the amplitude response / sensitivity of a deep-sea hydrophone with a depth distribution of deep-sea environmental noise, the steps are as follows:

[0033] (1) In the selected quiet deep-sea test area, try to avoid other passing ships to reduce the impact of the marine environment on the measurement results. Deploy the deep-sea hydrophones to be tested in the form of vertical linear arrays or distributed arrays, and use pressure sensors to record the deployment depth information of the hydrophones to be tested. Different frequencies f of the hydrophone to be tested k The nominal sensitivity is M0(f k ); Within 1000 meters (10Mpa hydrostatic pressure), at a certain depth, deploy two or more standard hydrophones or calibrated hydrophones, whose amplitude response is M B (f k ).

[0034] (2) After the measurement system is deployed, the test ship moves away from the measurement system and shuts down the main engine of the test ship to eliminate the influence of the test ship. The standard hydrophone or calibrated hydrophone and the hydrophone to be tested continuously record the ocean ambient noise for a period of time, with a sampling rate of f s (should be greater than twice the upper limit frequency of the measurement frequency band) and the time should be as long as possible to reduce the error of ocean environment fluctuations, such as more than 1 day. Synchronously measure the sound speed profile data (SSP), wind speed, seabed bottom characteristics and other ocean environment parameters during the experiment; after recovering the measurement system, use the power spectrum estimation method to calculate the measured ocean environment spectrum level NL averaged over one-third octave bandwidth exp .

[0035] (3) For the ship noise source, based on the automatic ship identification system (AIS) satellite data or the voluntary ship system (VOS) database, the space is divided according to a certain grid to obtain the distribution density d of different types of ships. S ; Then, based on the empirical formula of radiation source level of different types of ship radiation noise sources, the ship radiation noise source level NSL per unit area of ​​space is obtained ship (f k ,st); for wind noise sources, based on the National Center for Environmental Prediction (NCEP) database or the National Marine Environmental Prediction Center wind speed vwind Real-time data or reanalysis data are divided into certain grids in space to obtain the spatial distribution of wind speed. Then, based on the empirical formula of wind noise source level, the wind noise source level NSL per unit area of ​​space is obtained. wind (f k ,v wind ); the intensity of the monopole noise source per unit area can be expressed as

[0036] (4) Using the seabed topography, sound velocity profile and other marine environmental parameters of the test area, based on the principle of acoustic field reciprocity, using parabolic equations or ray methods, a noise field numerical calculation model is established, and the contribution of ship noise sources and wind noise sources to the total noise field is superimposed to obtain the vertical distribution characteristics of the deep-sea environmental noise spectrum level NL simu (z r ,f k ) (i.e. the noise spectrum level variation from the sea surface to the sea bottom, i.e. different hydrostatic pressures), calculate the one-third octave bandwidth average f k The simulated ocean environment spectrum level NL simu ;

[0037] (5) After eliminating the discrete interference in the noise data, a snapshot time period t i In the receiving depth-frequency two-dimensional plane, a simulated ocean environmental noise spectrum level matrix based on sound field calculation is constructed. Measured noise spectral level matrix based on calibrated hydrophones, hydrophones under test and sea trial data Analyze multiple snapshots (L1, L2, ..., L N ) ocean noise data, optimize the noise field numerical calculation process, make the calibrated hydrophone measured matrix and the simulation matrix consistent or the error is minimized, then the vertical distribution characteristics of the noise field NL simu (z r ,f k ) as the standard, and obtain the mean square error between the noise spectrum matrix of the hydrophone to be tested and the simulation noise spectrum matrix where e i (z r ,f k )=NL simu (z r ,f k )-NL exp (z r ,f k ), e 12 Compensate to the nominal sensitivity of the hydrophone to obtain the actual sensitivity of the hydrophone Get the corresponding snapshot time (t1, t2, ..., t N ) The amplitude response of the hydrophone to be tested (M1, M2, …, M N), find its mean (M=(M1+M2+…+M N ) / N) to reduce the error, and the mean value M is the final amplitude response of the hydrophone to be tested.

Claims

1. A method for measuring the amplitude response of a deep-sea hydrophone based on the depth distribution of deep-sea environmental noise field, characterized in that: The steps include: Step 1: In the selected test sea area, deploy the deep-depth hydrophones to be tested in the form of vertical linear arrays or distributed arrays, and use pressure sensors to record the deployment depth information of the hydrophones to be tested. q=1,2,...,Q, different frequencies f of the hydrophone to be tested k The nominal sensitivity is M0(f k ); Q represents the number of hydrophones, and q represents the serial number of hydrophones at different depths; Within 1000 meters underwater, at a certain depth, deploy two or more standard hydrophones or calibrated hydrophones, whose amplitude response is M B (f k ); Step 2: After the measurement system is deployed, the experimental ship moves away from the measurement system and shuts down the main engine of the experimental ship to eliminate the influence of the experimental ship; The standard hydrophone or calibrated hydrophone and the hydrophone to be tested continuously record the ocean ambient noise with a sampling rate of f s Greater than twice the upper limit of the measurement frequency band; synchronously measure other marine environmental parameters such as sound velocity profile data SSP, wind speed and seabed bottom characteristics during the experiment; after recovering the measurement system, use the power spectrum estimation method to calculate the measured marine environmental spectrum level NL averaged over one-third octave bandwidth exp ; Step 3: For the ship noise source, based on the Automatic Ship Identification System AIS satellite data or the Voluntary Ship System VOS database, the space is divided into grids to obtain the distribution density d of different types of ships. S ; Then, based on the empirical formula of radiation source level of different types of ship radiation noise sources, the ship radiation noise source level NSL per unit area of ​​space is obtained ship (f k ,st); For wind noise sources, based on the NCEP database of the National Center for Environmental Prediction or the wind speed v of the National Marine Environmental Prediction Center wind Real-time data or reanalysis data are divided into grids in space to obtain the spatial distribution of wind speed. Then, based on the empirical formula of wind noise source level, the wind noise source level NSL per unit area of ​​space is obtained. wind (f k ,v wind ); The intensity of the monopole noise source per unit area is expressed as Step 4: Test the seabed topography and sound velocity profile of the ocean environment parameters. Based on the principle of acoustic field reciprocity, use the parabolic equation or ray method to establish a noise field numerical calculation model, superimpose the contribution of ship noise sources and wind noise sources to the total noise field, and obtain the vertical distribution characteristics of the deep-sea environmental noise spectrum level NL simu (z r ,f k ), calculate the one-third octave bandwidth average f k The simulated ocean environment spectrum level NL simu ; z r It means that the pressure sensor is used to record the deployment depth information of the hydrophone to be tested; Step 5: After eliminating the discrete interference in the noise data, a snapshot time period t i In the receiving depth-frequency two-dimensional plane, a simulated ocean environmental noise spectrum level matrix based on sound field calculation is constructed. Measured noise spectral level matrix based on calibrated hydrophones, hydrophones under test and sea trial data Analyze multiple snapshots (L1, L2, ..., L N ) ocean noise data, and after making the measured matrix of the calibrated hydrophone and the simulation matrix consistent or with the minimum error, the vertical distribution characteristic NL simu (z r ,f k ) as the standard, and obtain the mean square error between the noise spectrum matrix of the hydrophone to be tested and the simulation noise spectrum matrix where e i (z r ,f k )=NL simu (z r ,f k )-NL exp (z r ,f k ), e 12 Compensate to the nominal sensitivity of the hydrophone to obtain the actual sensitivity of the hydrophone Get the corresponding snapshot time (t1, t2, ..., t N ) The amplitude response of the hydrophone to be tested (M1, M2, ..., M N ), find its mean M=(M1+M2+...+M N ) / N to reduce the error, and the mean value M is the final amplitude response of the hydrophone to be tested.

2. The method for measuring the amplitude response of a deep-sea hydrophone based on the depth distribution of the deep-sea environmental noise field according to claim 1 is characterized in that: The vertical distribution characteristics of the ambient noise spectrum level refer to the variation pattern of the noise spectrum level from the sea surface to the sea bottom, that is, different hydrostatic pressures.

3. A computer program, characterized in that The computer program enables a computer to execute the method according to any one of claims 1 to 2.

4. An electronic device, characterized in that: include: Processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device executes the method as claimed in any one of claims 1 to 2.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 2 is implemented.

6. A chip, characterized in that: include: A processor, configured to call and run a computer program from a memory, so that a device equipped with the chip executes a method as claimed in any one of claims 1 to 2.

7. A computer program product, characterized in that The computer program product comprises a computer storage medium storing a computer program, wherein the computer program comprises instructions executable by at least one processor, and when the instructions are executed by the at least one processor, the method according to any one of claims 1 to 2 is implemented.

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