Method for measuring amplitude response of large-depth hydrophone based on depth distribution of deep-sea environmental noise field

Abstract

The application discloses a kind of big depth hydrophone amplitude response measurement methods based on deep-sea environmental noise field depth distribution, by matching the field measurement result of the noise spectrum level received by calibrated hydrophone or standard hydrophone under low pressure, the noise field modeling result based on the ocean environmental parameter during measurement and sound field model, obtain the noise field full-depth distribution law of test sea area, then calculate the difference between its and the measured result of the hydrophone to be measured, compensate it to the nominal value of the amplitude response of the hydrophone to be measured, the amplitude response of the hydrophone to be measured in the big depth environment can be obtained.The application provides a new way for obtaining the sensitivity of hydrophone in deep-sea big depth environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of measurement, and particularly relates to a large-depth hydrophone amplitude response measurement method based on deep-sea environmental noise field depth distribution. BACKGROUND

[0002] With the working frequency of underwater acoustic communication and underwater acoustic detection equipment gradually developing towards the low frequency field and deep sea, it is urgent to establish a low frequency underwater acoustic metrological standard equipment and test method under high hydrostatic pressure to solve the problem of laboratory or field measurement of hydrophone amplitude response under high hydrostatic pressure. Under normal pressure, the "Acoustic Hydrophone Low Frequency Calibration Method (GB / T 4130-2000)" proposes a first level calibration method (including coupling cavity reciprocity method, piezoelectric compensation method, and vibrating liquid column method) and a second level calibration method (closed cavity comparison method and piston sound generator calibration method) for the sensitivity of hydrophones in the frequency band range of 1Hz-3.15kHz. The vibrating liquid column method is a method for determining the sound pressure sensitivity of the hydrophone by measuring the vibration acceleration, and this method is a national military standard. The coupling cavity and vibrating liquid column method test devices are generally not large, have certain requirements for the size of the transducer, and cannot measure multiple transducers at the same time, which is low in efficiency. The "Acoustic Transducer Measurement (GB / T 7965-2002)" proposes a free field sensitivity measurement method including reciprocity method and comparison method, which realizes the sensitivity measurement in the medium and high frequency band. The second level calibration of the hydrophone includes two methods: comparison between the calibrated hydrophone and the standard hydrophone, and comparison between the calibrated hydrophone and the standard transmitter. The first method is usually adopted, and the second method is rarely adopted. The comparison method needs to meet the free field condition. In addition, the reverberation sound field method mainly forms a relatively stable reverberation area in a limited space for testing. Due to the volume of the sound field and reflection, the ideal reverberation sound field condition cannot be met in practice. Although the spatial averaging can eliminate the unevenness of the reverberation sound field to some extent, the research and construction of the reverberation pool are not mature, and it is not yet in the practical stage. Under high hydrostatic pressure, the static capacitance of the piezoelectric element of the hydrophone will change significantly, which will have a great influence on the receiving sensitivity. Under the condition of 10MPa high hydrostatic pressure and 2-200kHz frequency band, according to the spherical wave reciprocity principle, the transfer impedance between the transmitting transducer, the reciprocal transducer and the receiving hydrophone is measured, and a standard hydrophone free field sensitivity calibration system based on a high-pressure anechoic tank is established. However, there is no effective measurement means for the sensitivity measurement of the hydrophone under higher hydrostatic pressure of 10MPa or more, and the sensitivity measurement of the hydrophone under 10MPa high hydrostatic pressure and below 2kHz low frequency band. SUMMARY

[0003] In order to overcome the prior art, the present application provides a large-depth hydrophone amplitude response measurement method based on deep-sea environmental noise field depth distribution, which matches the in-situ measurement results of the noise spectrum level received by the calibrated hydrophone or standard hydrophone under low pressure, obtains the noise field full-depth distribution law of the test sea area based on the noise field modeling results of the marine environmental parameters and sound field model during the measurement, then calculates the difference between the test results of the to-be-tested hydrophone, compensates the difference to the nominal value of the to-be-tested hydrophone amplitude response, and the to-be-tested hydrophone amplitude response in the large-depth environment is obtained. The present application provides a new way for obtaining the sensitivity of the hydrophone in the deep-sea large-depth environment.

[0004] The technical scheme adopted by the present application to solve the technical problems is as follows:

[0005] Step 1: In the selected test sea area, the to-be-tested large-depth hydrophone is arranged in the form of vertical linear array or distributed array, and the pressure sensor is used to record the depth information of the to-be-tested hydrophone The to-be-tested hydrophone has different frequencies f k The sensitivity nominal value is M0(f k ); Q represents the number of hydrophones, and q represents the serial number of the hydrophone at different depths;

[0006] Within 1000 meters under water, two or more standard hydrophones or calibrated hydrophones are arranged at certain depths, and the amplitude response of the standard hydrophone or calibrated hydrophone is M B (f k );

[0007] Step 2: After the measurement system is arranged, the experimental ship is far away from the measurement system and the main engine of the experimental ship is turned off to eliminate the influence of the experimental ship;

[0008] The standard hydrophone or calibrated hydrophone and the to-be-tested hydrophone continuously record the marine environmental noise, and the sampling rate f s is greater than twice the upper limit frequency of the measurement frequency band; the sound speed profile data SSP, wind speed and seabed characteristics and other marine environmental parameters during the experiment are measured synchronously; after the measurement system is recovered, the measured marine environmental spectrum level NL exp is calculated by using the power spectrum estimation method in the one-third octave bandwidth.

[0009] Step 3: For the ship noise source, the grid is divided in space based on the AIS satellite data of the automatic ship identification system or the VOS database of the voluntary ship system, and the distribution density d S of different types of ships is obtained; then based on the empirical formula of the radiation noise source level of different types of st ship radiation noise sources, the spatial unit area ship radiation noise source level NSL ship (f k ,st) is obtained.

[0010] For the wind closure noise source, based on the NCEP database of the National Environmental Forecasting Center or the wind speed v wind The real-time data or reanalysis data are divided by grid in space to obtain the spatial distribution of wind speed, and then based on the wind closure noise source level empirical formula, the spatial unit area wind closure noise source level NSL is obtained wind (f k ,v wind );

[0011] The monopole noise source strength in unit area is expressed as

[0012] Step 4: Test the sea bottom topography, sound speed profile and other marine environmental parameters, based on the reciprocity principle of sound field, use parabolic equation or ray method to establish a numerical calculation model of noise field, superimpose the contributions of ship noise source and wind closure noise source to the total noise field, and obtain the vertical distribution characteristics of deep sea environmental noise spectrum level NL simu (z r ,f k ), calculate the simulation marine environmental spectrum level NL k f simu of one-third octave bandwidth average; z r represents the information of the depth of the water sensor to be measured recorded by the pressure sensor;

[0013] Step 5: After excluding the discrete interference in the noise data, in a fast snap time period t i , a simulation marine environmental noise spectrum level matrix based on sound field calculation is constructed on the receiving depth-frequency two-dimensional plane Based on the calibrated hydrophone, the measured noise spectrum level matrix of the water sensor to be measured and the sea trial data Analyze the marine noise data of multiple snaps (L1, L2,..., L N ), make the measured matrix of the calibrated hydrophone and the simulation matrix consistent or the error minimum, and then take the noise field vertical distribution characteristics NL simu (z r ,f k ) at this time as the standard, obtain the mean square error between the noise spectrum level matrix of the water sensor to be measured and the simulation noise spectrum level matrix Where e i (z r ,f k ) = NL simu (z r ,f k )- NL exp (z r ,f k ), compensate e 12 to the nominal sensitivity of the water sensor to be measured, and obtain the measured sensitivity of the water sensor to be measured acquire the amplitude responses (M1, M2, …, M N ) of the hydrophone to be measured at the corresponding snapshot time (t1, t2, …, t N ), calculate the average value M=(M1+M2+…+M k ) / N to reduce the error, and the average value M is the final amplitude response of the hydrophone to be measured.

[0014] Preferably, the vertical distribution characteristics of the ambient noise spectrum level refer to the variation of the noise spectrum level from the sea surface to the sea bottom, i.e., different hydrostatic pressures.

[0015] A computer program, which causes a computer to execute the above-mentioned large-depth hydrophone amplitude response measurement method.

[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, which stores a computer program, and the computer program is executed by a processor to implement the above-mentioned large-depth hydrophone amplitude response measurement method.

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

[0019] A computer program product, which comprises a computer storage medium, the computer storage medium stores a computer program, and the computer program comprises instructions executable by at least one processor, and the instructions are executed by the at least one processor to implement the above-mentioned large-depth hydrophone amplitude response measurement method.

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

[0021] 1) The present application realizes accurate measurement of the sensitivity of a deep-sea large-depth hydrophone under high hydrostatic pressure, especially high hydrostatic pressure greater than 10 MPa; 2) The present application has low requirements on the size of the hydrophone, and can realize simultaneous measurement of multiple hydrophones or under different pressures, and has high measurement efficiency; 3) The present application covers a wide frequency band range, and basically realizes measurement of the sensitivity of a hydrophone in a commonly used frequency band (including a low frequency band); 4) The present application utilizes the ocean background field, does not need to emit a sound source device or a vibration test platform, can be implemented simultaneously with other active underwater acoustic tests and amplitude response measurement of the hydrophone, does not need to calibrate the equipment before the test, and has high utilization rate of test facilities and time. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The overall flow chart of the amplitude response measurement of the large-depth hydrophone of the present application;

[0023] Figure 2 The schematic diagram of the ocean environment parameters and noise source distribution of the embodiment of the present application, (a) the sound velocity profile and the anchoring structure, (b) the seafloor topography, (c) the wind-related noise source, (d) the ship noise source;

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

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

[0026] Figure 5 The sensitivity change value (the nominal value is -190 dB, and the mean value is the coarse dashed line) of the hydrophone to be measured of the embodiment of the present application;

[0027] Figure 6 The compensated noise spectrum level of the amplitude response of the 8# hydrophone to be measured (receiving depth 3718 m) of the embodiment of the present application;

[0028] Figure 7 The propagation loss results of the amplitude response of the 8# hydrophone to be measured (100 Hz) of the embodiment of the present application, (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 The comparison of the propagation loss of different frequencies obtained by the nominal value and the measured value of the amplitude response of the 8# large-depth hydrophone to be measured of the embodiment of the present application, (a) SD=50 m, nominal value, (b) SD=50 m, measured value, (c) SD=300 m, nominal value, (d) SD=300 m, measured value. DETAILED DESCRIPTION

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

[0031] This invention proposes a method for measuring the amplitude response / sensitivity of a deep-sea hydrophone in terms of the depth distribution of deep-sea environmental noise. By constructing a matching objective function between the field measurement value of the noise spectrum level received by a calibrated or standard hydrophone under low pressure and the noise field modeling value based on the marine environmental parameters and sound field model during the measurement period, the theoretical law of the depth distribution of marine noise field in the test sea area is obtained. The difference between the measured value of the hydrophone under test and the theoretical law is calculated and compensated into the nominal value of the amplitude response of the hydrophone under test, thus realizing the measurement of the amplitude response of the hydrophone under test in highly still water.

[0032] A method for measuring the amplitude response / sensitivity of a deep-sea hydrophone in measuring the depth distribution of deep-sea environmental noise, comprising the following steps:

[0033] (1) In the selected quiet deep-sea test area, with as few other ships passing by as possible to reduce the impact of the marine environment on the measurement results, deploy the hydrophones to be tested at great depths in the form of a vertical linear array or a distributed array, and use pressure sensors to record the deployment depth information of the hydrophones to be tested. Different frequencies f of the hydrophone under test k The nominal sensitivity value is M0(f) k Within a depth of 1000 meters (10 MPa hydrostatic pressure), at certain intervals, deploy two or more standard or calibrated hydrophones, and their amplitude response is M. B (f k ).

[0034] (2) After the measurement system is deployed, the experimental vessel is moved away from the system and its main engine is shut down to eliminate any influence from the vessel. Standard or calibrated hydrophones and the hydrophone under test continuously record marine environmental noise for a period of time at a sampling rate f. s (The frequency should be greater than twice the upper limit of the measurement band), and the measurement time should be as long as possible to minimize errors caused by fluctuations in the marine environment, such as more than one day. Simultaneously measure sound velocity profile (SSP), wind speed, seabed sediment characteristics, and other marine environmental parameters during the experiment; after recovering the measurement system, calculate the measured marine environmental spectral level NL (averaged by one-third octave band) using power spectrum estimation methods. exp .

[0035] (3) For ship noise sources, based on Automatic Ship Identification System (AIS) satellite data or 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 empirical formulas for the radiated noise level of different types of ship radiated noise sources, the NSL (Noise Level of Ship Radiation) per unit area of ​​space is obtained. ship (f k For wind-related noise sources, based on the National Center for Environmental Forecasting (NCEP) database or the National Marine Environmental Forecasting Center's wind speed v...wind Real-time data or reanalysis data is divided in space according to a certain grid to obtain the spatial distribution of wind speed, and then based on the empirical formula of wind noise source level, the spatial unit area wind noise source level NSL is obtained wind (f k ,v wind ); the monopole noise source strength in unit area can be expressed as

[0036] (4) Using the seabed topography, sound speed profile and other marine environmental parameters of the test sea area, based on the reciprocity principle of sound field, using parabolic equation or ray method, a numerical calculation model of noise field is established, the total noise field contribution of ship noise source and wind noise source is superimposed, and the vertical distribution characteristics of deep sea ambient noise spectrum level NL are obtained simu (z r ,f k ) (i.e. the change rule of noise spectrum level from sea surface to seabed, i.e. different hydrostatic pressure), the simulation of marine environment spectrum level NL k f simu of one-third octave bandwidth average is calculated;

[0037] (5) After excluding the discrete interference in the noise data, in a snapshot time period t i , a simulation matrix of marine environmental noise spectrum level based on sound field calculation is constructed on the receiving depth-frequency two-dimensional plane Based on the calibrated hydrophone, the measured noise spectrum level matrix of the tested hydrophone and the sea trial data Analysis of marine noise data of multiple snapshots (L1, L2, …, L N ) optimizes the numerical calculation process of noise field, so that the measured matrix and the simulation matrix of the calibrated hydrophone are consistent or the error is minimized, and then the noise field vertical distribution characteristics NL simu (z r ,f k ) at this time are taken as the standard to obtain the mean square error between the noise spectrum level matrix of the tested hydrophone and the simulation noise spectrum level matrix Where e i (z r ,f k ) = NL simu (z r ,f k ) - NL exp (z r ,f k ), e 12 is compensated to the nominal sensitivity of the tested hydrophone to obtain the measured sensitivity of the tested hydrophone The corresponding snapshot time (t1, t2, …, t N ) is obtained The amplitude response (M1, M2, …, M N), and its mean value (M = (M1+ M2+…+M N ) / N) is calculated to reduce error, and the mean value M is the final amplitude response of the hydrophone to be measured.

Claims

1. A method for measuring the amplitude response of a deep-ocean hydrophone based on the depth distribution of the ambient noise field in the deep sea, characterized in that, The method comprises the following steps: Step 1: In the selected test sea area, the to-be-tested large-depth hydrophone is arranged in the form of vertical line array or distributed array, and the pressure sensor is used to record the arrangement depth information of the to-be-tested hydrophone Different frequencies f of the to-be-tested hydrophone l The nominal value of the sensitivity is M0(f l ); Q represents the number of hydrophones, and q represents the serial number of the hydrophone at different depths Within 1000 meters of the water surface, at intervals of depth, two or more standard hydrophones or calibrated hydrophones are deployed, whose amplitude response is M B (f l ); Step 2: After the measurement system is laid out, the experimental ship is far away from the measurement system and the main engine of the experimental ship is turned off to eliminate the influence of the experimental ship; Both the standard hydrophone or calibrated hydrophone and the hydrophone to be measured record the ocean ambient noise continuously, and the sampling rate f s is greater than twice the upper limit frequency of the measured frequency band; the sound speed profile data SSP, wind speed and seabed characteristics during the synchronous measurement experiment are measured; after the measurement system is recovered, the measured ocean ambient spectrum level NL is calculated by using the power spectrum estimation method with one-third octave band average exp ; Step 3: Based on the AIS satellite data or VOS database, the spatial distribution density d of different types of ships is obtained by dividing the space with a grid for the ship noise source S ; Then, based on the empirical formula of the radiation source level of different types of ship radiation noise sources, the spatial unit area ship radiation noise source level NSL ship (f l ,st) is obtained. For wind-related noise sources, based on the National Environmental Prediction Center NCEP database or the National Oceanic and Environmental Prediction Center wind speed v wind Real-time data or reanalysis data, divided by grid in space, get the spatial distribution of wind speed, then based on the wind-related noise source level empirical formula, get the spatial unit area of wind-related noise source level NSL wind (f l ,v wind ); The monopole noise source strength in a unit area is expressed as Step 4: test the sea bottom topography and the sound speed profile of the sea environment parameters, based on the sound field reciprocity principle, use the parabolic equation or ray method to establish a numerical calculation model of the noise field, superimpose the contribution of the ship noise source and the wind noise source 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 simulation of the vertical distribution characteristics of the ocean environmental noise spectrum level NL k f simu ; z r represents recording the depth information of the to-be-tested hydrophone by using a pressure sensor; Step 5: After removing the discrete interference in the noise data, a snapshot time period t i In the receiving depth-frequency two-dimensional plane, the simulation ocean ambient noise spectrum level matrix based on the sound field calculation is constructed The measured noise spectrum level matrix based on the calibrated hydrophone, the to-be-tested hydrophone and the sea trial data The ocean noise data of multiple snapshots (L1, L2,..., L N ) are analyzed, and the to-be-tested hydrophone measured matrix and the simulation matrix are made consistent or the error is minimized simu (z r ,f k ) is taken as the standard, the mean square error between the to-be-tested hydrophone noise spectrum level matrix and the simulation noise spectrum level matrix is obtained Where e i (z r ,f k ) = NL simu (z r ,f k ) - NL exp (z r ,f k ), the e 12 is compensated into the to-be-tested hydrophone nominal sensitivity, and the to-be-tested hydrophone measured sensitivity is obtained The to-be-tested hydrophone amplitude response (M1, M2,..., M N ) at the corresponding snapshot time (t1, t2,..., t N ) is obtained, and the mean value M = (M1 + M2 + … + M N ) / N is calculated to reduce the error, and the mean value M is the final to-be-tested hydrophone amplitude response.

2. The method according to claim 1, wherein, The vertical distribution characteristics of the ambient noise spectrum level refer to the variation of the noise spectrum level from the sea surface to the sea bottom, i.e.

3. An electronic device, comprising: Comprise: A processor and a memory; The memory is used for storing a computer program, and the processor is used for executing the computer program stored in the memory, so that the electronic device executes the method in any one of claims 1-2.

4. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the method in any one of claims 1-2.

5. A chip, characterized by Comprise: A processor is used for calling and running a computer program from a memory, so that the device installed with the chip executes the method in any one of claims 1-2.

6. A computer program product, characterised in that, The computer program product comprises a computer storage medium, the computer storage medium stores a computer program, and 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 in any one of claims 1-2 is implemented.

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