CN109489799A - A kind of Bottom sound speed substep inversion method based on double vector hydrophones - Google Patents
A kind of Bottom sound speed substep inversion method based on double vector hydrophones Download PDFInfo
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Abstract
The present invention relates to a kind of Bottom sound speed substep inversion method based on double vector hydrophones, first with the vertical vibration velocity signal reconstruction vertical direction point-to-point transmission sound field Green's function of noise field, extract the arrival structure on different more ways, to obtain the relational expression between the velocity of sound and thickness of seabed layered structure and each layer of sedimentary, then corresponding seafloor model is selected, finally using the vertical vibration velocity signal vertical coherence characteristic of noise field come the Inversion for bottom velocity of sound.Substep inversion method proposed by the present invention can guarantee that the seafloor model selected in inverting is correctly, to provide guarantee for the accuracy of inversion result.Furthermore substep inversion method can characterize the submarine sedimentary strata velocity of sound with thickness with an inverting amount, and the dimension of parameter search space when reducing inverting improves the efficiency of inverting.
Description
Technical field
The invention belongs to Underwater acoustic signal processing technologies, are related to a kind of Bottom sound speed substep inverting based on double vector hydrophones
Method.
Background technique
Ambient sea noise is the background sound field in ocean, it is always carved, and there are in Yu Haiyang.Any sonar set
Performance can all be influenced by ambient sea noise.Traditional marine acoustics is by ambient sea noise signal as interference letter
Number, the purpose for studying noise field is to inhibit noise, improves signal-to-noise ratio, promotes the operating distance of sonar set to the full extent.
In fact, ambient sea noise signal constantly interacts with sea and seabed in communication process, so can take in noise field
Band ocean environment parameter (especially bottom parameters) information, therefore can use noise field spatial character and come passive inverting acquisition sea
The parameters,acoustic at bottom.Relative to active inversion method, passive inversion method can save research cost without actively emitting signal
And good concealment.Currently with the passive inverting of eolian noise there are mainly two types of approach for sound parameter, simple separately below to introduce:
The first approach is that the inverting of ground sound parameter is carried out using underwater ambient noise vertical directivity structure, is used
Small more array element vertical linear arrays of spacing receive ambient sea noise signal, do to noise signal is received in different graze angular direction
Wave beam forming obtains the intensity of acoustic wave that all directions reach in noise field, is obtained by doing ratio to uplink beam and downlink wave beam
Bottom reflection coefficient constructs cost function with actual measurement bottom reflection coefficient using theoretical, optimizing algorithm appropriate is then selected to search
One group of optimized parameter of rope makes cost function optimal, so that inverting obtains the reflection coefficient in practical seabed.Since submarine acoustic is joined
Number can influence significantly bottom reflection coefficient, so can cross inverting with noise field vertical directivity structure obtains relatively accurate ground
Sound parameter.But this method needs orthogonal array to be just able to achieve and has higher requirement to array element quantity and array element spacing.
Furthermore vertical array lay recycle relatively cumbersome and underwater vertical array posture it is difficult to ensure that, therefore vertically referred to noise field
The cost of next inverting the sound parameter of tropism is higher and operation difficulty is larger.
Second of approach is using noise field vertical coherence characteristic come inverting.This method only needs two water vertically laid
Device is listened, whole system lays the relatively easy and underwater relatively good guarantee of posture.By received to two hydrophones
Noise signal, which does cross-correlation and does normalized, obtains point-to-point transmission coherent function, then with the relevant letter of actual measurement and theoretical noise field
Number construction cost function carrys out inverting and obtains submarine acoustic parameter.What big multi-method all utilized at present is hanging down for noise field sound pressure signal
Straight coherent structure is come what is realized, and Zhou Jianbo et al. is using noise field vertical coherence structure to this more sensitive spy of Bottom sound speed
Sign, proposes a kind of Bottom sound speed inversion method based on the vertical vibration velocity signal coherence structure of noise field, obtains more accurately
Bottom sound speed inversion result.
Above two inversion method assumes that seabed layered structure is known, and needs to cut open equal acoustics by shallow in practice
Equipment could obtain the layered structure in seabed, and the shallow acquisition seabed layered structure needs that cut open is utilized actively to emit acoustic signals, just
The advantage of passive inverting can be lost.
Summary of the invention
Technical problems to be solved
In order to avoid the shortcomings of the prior art, the present invention proposes a kind of Bottom sound speed based on double vector hydrophones point
Inversion method is walked, Bottom sound speed is obtained rapidly and accurately with smaller cost.
Technical solution
A kind of Bottom sound speed substep inversion method based on double vector hydrophones, it is characterised in that steps are as follows:
Step 1 establishes the sound field Green's function extraction model based on the vertical vibration velocity signal of noise field:
Acoustic pressure cross-spectral density function:
Vertical vibration velocity cross-spectral density function:
Acoustic pressure time-space correlation function:
Vertical vibration velocity time-space correlation function:
Wherein: q2For noise source spectral intensity, k2For with reference to wave number, um(z) and u 'mIt (z) is m rank eigenfunction in depth z
The value and its derivative at place, kmFor m rank characteristic value, R0For the radius of noise source disk, ρ and c are respectively water body density at sound source
And the velocity of sound,Indicate inversefouriertransform, ω is angular frequency, and τ is time delay；Acoustic pressure/vertical vibration velocity time-space correlation function is proportional to
Sound field time domain Green function passes through extraction so each relevant peaks correspond to different more way arrival times in time-space correlation function
Different multipath structure arrival times can obtain the pass in the layered structure and every layer of sedimentary in seabed between the velocity of sound and thickness
It is formula；
Step 2 establishes the Bottom sound speed substep inverse model based on double vertical velocity hydrophones:
Normalized is done to two spot noise cross-spectral density functions and obtains theoretical noise field vertical coherence function C12(ω):
Survey noise field vertical coherence functionSolution procedure is as follows:
Wherein: N is data snapshot sum, and Δ T is each snapshot data length, X1(f,ΔTn) and X2(f,ΔTn) respectively
For the Frequency Domain Solution for the vertical vibration velocity signal of n-th of snapshot noise field that first hydrophone and second hydrophone acquire；
Step 3 provides the Bottom sound speed inverse model based on noise field vector signal vertical coherence characteristic:
Wherein: FcostFor cost function, N is the frequency point sum considered, Γ andRespectively theoretical and actual measurement noise field sound
Pressure/vertical vibration velocity coherent function；Characteristic value and eigenfunction equivalent in Γ are needed seawater parameters,acoustic, submarine acoustic parameter
And receiver parameters,acoustic is input in propagation model and is calculated；
The layered structure in seabed and the relationship of Bottom sound speed and thickness can be obtained by step 1, if seabed is half nothing
Seabed is limited, then the bottom parameters collection Ω to inverting can be expressed as Ω=[cb,ρb,αb], if there are K layers of sedimentary in seabed, that
Bottom parameters collection Ω to inverting can be expressed as
Ω=[cb1,ρb1,αb1,hb1…cbK,ρbK,αbK,hbK,cbK+1,ρbK+1,αbK+1]；
Wherein K+1 layers of expression semo-infinite basal layer
One group of parameter is searched in given submarine acoustic parameter search space Ω using niche genetic algorithmSo that
Cost function FcostMinimum, then this group of parameter is true bottom parameters.
Beneficial effect
A kind of Bottom sound speed substep inversion method based on double vector hydrophones proposed by the present invention, it is first vertical with noise field
Vibration velocity signal reconstruction vertical direction point-to-point transmission sound field Green's function, extracts the arrival structure on different more ways, to obtain seabed point
Relational expression between layer structure and the velocity of sound and thickness of each layer of sedimentary, then selects corresponding seafloor model, finally
Using the vertical vibration velocity signal vertical coherence characteristic of noise field come the Inversion for bottom velocity of sound.Substep inversion method proposed by the present invention can
Guarantee that the seafloor model selected in inverting is correctly, to provide guarantee for the accuracy of inversion result.Furthermore substep is anti-
The method of drilling can characterize the submarine sedimentary strata velocity of sound with thickness with an inverting amount, parameter search space when reducing inverting
Dimension improves the efficiency of inverting.
Present invention combination vector hydrophone is mentioned in advantage of both the acquisition of seabed layered structure and Bottom sound speed acquisition
Go out the Bottom sound speed substep inversion method based on double vector hydrophones: first obtaining practical seabed with the vertical vibration velocity signal of noise field
Layered structure, the seafloor model that then reselection and practical seabed match carry out inverting.The present invention only needs two vertical vibration velocitys
Hydrophone waits acoustic equipments without active sound source or shallow cut open, with experimentation is low, experimental implementation is simple, hidden
The advantages that covering property is high has stronger engineering application value.
Detailed description of the invention
Fig. 1: semo-infinite seabed waveguide schematic diagram
Fig. 2: the double-deck seabed waveguide schematic diagram
Fig. 3: more ways are extracted with the vertical vibration velocity correlation function of (a) acoustic pressure correlation function derivative (b) in the waveguide of semo-infinite seabed
Structure；
Fig. 4: multipath structure is extracted with acoustic pressure correlation function derivative in semo-infinite seabed
Fig. 5: multipath structure is extracted with acoustic pressure correlation function derivative in the double-deck seabed
Fig. 6: the Sound speed profile of actual measurement
Fig. 7: experimental facilities lays schematic diagram
Fig. 8: pressure hydrophone extracts multipath structure (a) 30s data；(b) 60s data；(c) 120s data；(d)600s
Data；
Fig. 9: vertical velocity hydrophone extracts multipath structure (a) 30s data；(b) 60s data；(c) 120s data；(d)
600s data
Figure 10: multilayer seabed waveguide sub-bottom reflection echo schematic diagram
The multipath structure extracted under Figure 11: I class waveguide environmental with vertical velocity hydrophone
Figure 12: influence of the seafloor model of mismatch to sound field forecast result is selected
Vertical velocity hydrophone extracts multipath structure under Figure 13: II class waveguide environmental
Figure 14: influence of the seafloor model of mismatch to sound field forecast result is selected
Figure 15: the bottom parameters substep inversion process figure based on double vector hydrophones
Specific embodiment
Now in conjunction with embodiment, attached drawing, the invention will be further described:
First with the vertical vibration velocity signal reconstruction sound field Green's function of noise field, extraction is vertically split between two hydrophones
More ways reach structure, reach structure using difference mostly way and obtain submarine sedimentary strata layered structure and every layer of deposit thickness and sound
Relational expression between speed.Then corresponding seafloor model is selected to carry out inverting, finally utilizes the vertical vibration velocity signal of noise field
Coherent structure carries out the inverting of Bottom sound speed.The present invention mainly is unfolded to introduce from the following aspects: initially setting up and is based on making an uproar
The sound field Green's function extracting method of the vertical vibration velocity signal of sound field proves that vertical velocity hydrophone can be wanted very much by theoretical simulation
Inhibition distant place interference source influence, be experimentally confirmed vertical velocity hydrophone can greatly be promoted Green's function reconstruct
Efficiency.Then substep inverse model is given, by emulating the influence for discussing the seafloor model of selection mismatch and forecasting to sound field,
Demonstrate the necessity of substep inverting.This two parts is introduced respectively below.
(1) it establishes the sound field Green's function based on the vertical vibration velocity signal of noise field and extracts model
1. theoretical modeling
The sonic pressure field Green's function G of point dynamite source in horizontal slice waveguidePWith vertical vibration velocity field Green's function GVIt is respectively as follows:
Wherein knAnd unThe respectively characteristic value and eigenfunction of n-th order normal mode, ρ0For water body density, subscript at sound source
[] ' indicate that Derivative Operation symbol, N are the order of the mode considered, N=N1+N2+N3, wherein N1、N2、N3Respectively waveguide normal mode
The order of order, the non-waveguide normal mode order of truncation and the discrete mode for approximate continuous spectrum contribution.It obtains accurate
Near field sound field solution, need to consider the contribution of continuous spectrum and the contribution of non-waveguide normal mode multistage enough.
Assuming that seabed is horizontal slice, the velocity of sound in seawater and seabed, density and decaying are only related with depth, and and away from
From unrelated, noise source is evenly distributed on z under seasDepth, two hydrophones vertically split are located at z1And z2In depth, half
Diameter is R0Disk internal noise source act on lower z1With z2Point-to-point transmission noise field acoustic pressure cross-spectral density function and vertical vibration velocity cross-spectrum are close
Degree function is respectively as follows:
(1) formula is updated to (3) formula, (2) formula, which is updated to (4) formula progress abbreviation, can be obtained noise in horizontal slice medium
Acoustic pressure cross-spectral density function and vertical vibration velocity cross-spectral density function.It should be strongly noted that due to considering the non-wave of high-order
Lead normal mode be used to approximate continuous spectrum discrete normal mode contribution, the corresponding characteristic value imaginary part of these normal modes often compared with
Greatly, so the coherent term between different normal modes cannot be ignored during to (3) formula and (4) formula abbreviation.
The available space point-to-point transmission noise field vertical coherence function of normalized is done to (5) formula and (6) formula:
Wherein ωmFor m-th of angular frequency point.C12For z1And z2Noise field vertical coherence function between two receiving points.
Inverse-Fourier transform is done to (5) formula and (6) formula respectively and obtains coherent function time-domain expression:
WhereinIndicate inverse-Fourier transform operator.
The sound field Green's function between two receiving points can be obtained in (8) formula of utilization, and sound field Green's function is able to reflect sound source
Multi-path propagation structure between receiving point, using way arrival time more than difference may determine that seabed layered structure and each layer
Relationship between middle deposit thickness and sedimentary velocity of sound the two.
Reconstruct is vertically split between two hydrophones for sound field Green's function, only the noise on hydrophone line top
Source has stable cross-correlation phase, in cross-correlation procedure can coherent superposition, the noise sources of other positions shaken due to phase
It swings and cancels out each other.In view of fluctuation effect, the usually noise source near hydrophone line in Fresnel region plays main tribute
It offers.So for reconstructing and vertically splitting point-to-point transmission sound field Green's function, only close to the acoustic signals of vertically propagating
For useful signal, the signal that other directions are propagated is as existing for interference.In practical Oceanic waveguide, what horizontal direction was propagated makes an uproar
Noise energy of the acoustic energy much stronger than vertically propagating.Since pressure hydrophone is omnidirectional, receives and come from each side
To acoustic wave energy generally require very prolonged noise so reconstructing sound field Green's function with two pressure hydrophones
(noise data for generally requiring several hours or even more than ten hour) does cross-correlation and adds up that low-angle propagation can be inhibited
Interference signal extracts the clearly multipath structure of vertically propagating relatively.In addition, when hydrophone nearby has strong interference source
In the presence of, virtual more ways are often extracted with pressure hydrophone and reach structure, seabed accurate judgement layered can be made
At interference.Vertical velocity hydrophone has dipole directive property in vertical direction, and low-angle can be inhibited to propagate well
Acoustic wave energy improves the signal-to-noise ratio of vertically propagating signal, so more ways of point-to-point transmission can be extracted within a short period of time
Transmission structure.In addition, vertical velocity hydrophone can effectively inhibit the nonstationary noise in a distant place in the directive property of vertical direction
The interference in source (such as boat noise, drilling platforms work noise), to inhibit the virtual appearance for reaching structure.Therefore Vertical Vibrating
Fast hydrophone has great superiority compared with pressure hydrophone in terms of vertical direction sound field Green's function reconstruct.
2. simulation analysis
The ocean environment parameter of emulation is shown in Fig. 1 and Fig. 2, Hai Shen 86m, and the velocity of sound is 1500m/s in water, and noise source is located at sea
On infinity plane in lower 0.1m depth.The frequency of sound wave range of emulation is 100-1500Hz.Vertical reception battle array is located at 20m-
Within the scope of the 80m depth of water.Consider that whether there is or not two kinds of situations of layering in seabed: (1) seabed is respectively without layering, substrate longitudinal wave velocity and density
1800m/s and 2.0g/cm3.(2) floor parameter is identical when there are layering, floor parameter and seabed in seabed without layering, sedimentary longitudinal wave
The velocity of sound and density are respectively 1600m/s and 1.5g/cm3。
Cross-correlation is done to two received noise signals of hydrophone and does inversefouriertransform, obtained time domain cross-correlation letter
It is exactly the theory of the Acoustic Wave Propagation that emits with reference to hydrophone as virtual sound source to other hydrophones that several each peak values is corresponding
Arrival time.Acoustic pressure correlation function derivative under 1 environment of analogous diagram, seabed decaying take 0.2dB/ λ, and battle array spacing is the linear array cloth of 1m
It is placed within the scope of water body 20m-80m.Simulation process are as follows: using vertical array top hydrophone as hydrophone is referred to, (8) formula of utilization is asked
Noise field acoustic pressure cross-spectral density and vertical vibration velocity cross-spectral density between other hydrophones and reference hydrophone are solved, then is anti-Fu to it
In leaf transformation obtain cross-correlation function time solution.
What Fig. 3 (a) was provided is to reach structure with more ways that pressure hydrophone extracts, and Cong Tuzhong can be clearly seen that four
More way paths, successively are as follows: a bow wave, direct wave, seabed primary reflection and sea primary reflection.Wherein bow wave reaches road
Diameter is not that physics reaches path, so being sometimes also referred to as virtual bow wave.Virtual bow wave is propagated with seabed critical angle,
His way more than three is propagated with 90 ° of angles.What Fig. 3 (b) was provided is to reach structure with more ways that vertical velocity hydrophone extracts,
Obviously virtual bow wave can be effectively inhibited with vertical velocity hydrophone reach structure, virtual bow wave is propagated with critical angle,
The acoustic signals main energetic of the boat noise source excitation in a distant place is to be less than critical angle and propagate, and vertical velocity hydrophone is to small
It is more insensitive in the sound wave that critical angle is propagated, so reconstructing sound field Green's function with vertical velocity hydrophone can centainly have
Effect inhibits the interference in distant place nonstationary noise source.
What Fig. 4 was provided is acoustic pressure field correlation derivative under Fig. 2 waveguide environmental, because the emphasis that bow wave is not this paper is ground
Object is studied carefully, so seabed attenuation of P-wave takes 1.0dB/ λ in emulation, so being substantially not visible bow wave reaches structure.In simulation result
First three bright line respectively represents: a direct wave；B bottom echo；C sea surface reflection wave.In the situation known to the water body velocity of sound, by
Direct wave can be estimated sea water advanced with bottom echo arrival time, can be estimated by direct wave and sea surface reflection wave arrival time
Meter receives position of the battle array in water body.
What Fig. 5 was provided is acoustic pressure cross-correlation function derivative under Fig. 2 waveguide environmental.Preceding four bright lines respectively represent: a is through
Wave；Interface echo in b sedimentary；C sea surface reflection wave；Interface echo under d sedimentary.Utilize interface in sedimentary and lower bound
Difference Δ t can determine the thickness deltat H and sedimentary velocity of sound c of sedimentary at the time of face back wave reachessRelationship, it is assumed that sedimentary
The velocity of sound is the uniform velocity of sound, then three meets 2 Δ H=cs×Δt。
3. experimental verification
Carry out vector ambient sea noise using dual vector hydrophone array at the South Sea and obtains experiment.Experiment is selected in south
Extra large neritic area, close constant, the Hai Shenyue 86m of level in experiment sea area seabed.Sound velocity in seawater section is as shown in Figure 6.Seabed longitudinal wave sound
Speed, density, attenuation of P-wave coefficient are respectively 1604m/s, 1.74g/cm3,0.45dB/λ.Experimental facilities lays schematic diagram and sees Fig. 7.
Dual vector hydrophone array is suspended on board, and two hydrophone array element spacing are 18m, No. 1 and No. 2 vector hydrophones distance respectively
Sea 25m and 43m.
What Fig. 8 was provided is the acoustic pressure correlation function derivative that Data Processing in Experiment obtains, (a)-(d) correspond respectively to 30s,
The result that 60s, 120s and 600s acoustic pressure data are handled.Three red point vertical lines correspond respectively to direct wave, sea in figure
Back wave and bottom echo theoretical arrival time.As we can see from the figure: direct wave can be extracted with the data of 30s
Structure is reached, but there are many correlation peaks after direct wave, with the increase for the noise data length being averaged, correlation function
Amplitude scintillation it is smaller and smaller, when the data length being averaged increases to 600s, in bottom echo position of theoretical arrival time
There are a relevant peaks, but the amplitude of the relevant peaks is weaker, can not judge whether the relevant peaks are that bottom echo reaches.
What Fig. 9 was provided is the vertical vibration velocity correlation function that Data Processing in Experiment obtains.It can be with the vertical vibration velocity data of 30s
Direct wave is extracted, there are a relevant peaks near bottom echo theoretical arrival time, but the correlation peak-to-peak amplitude is weaker, it can not
Whether accurate judgement is that bottom echo reaches.When the vertical vibration velocity data length being averaged increases to 60s, so that it may relatively more clear
Bottom echo is seen clearly.The data length being averaged is continued growing, direct wave and bottom echo arrival structure are more clear
It is clear.Comparison diagram 8 can see, and not extract bottom echo using the acoustic pressure data of 600s, and use the vertical vibration velocity of 60s
Data can extract bottom echo.Relative to pressure hydrophone, the efficiency of multipath structure is extracted with vertical velocity hydrophone
Improve 10 times or more.
4. conclusion
Emulation with the results showed that reconstructing vertical direction point-to-point transmission sound field Green's function with vertical velocity hydrophone more
Tool advantage.On the one hand, the dry of distant place nonstationary noise source can effectively be inhibited with vertical vibration velocity signal reconstruction sound field Green's function
It disturbs, extracts true physics multipath structure, provided safeguard to extract correct seabed layered structure.On the other hand, Vertical Vibrating
Fast hydrophone has dipole directive property in vertical direction, can effectively promotion signal ratio, can greatly promote Green
The efficiency of function reconstruct, provides seabed layered structure priori knowledge for the quick obtaining of submarine acoustic parameter.
(2) based on the Bottom sound speed substep inversion method of double vertical velocity hydrophones
1. theoretical modeling
Different more ways in waveguide, which can be extracted, using noise signal known to the introduction of front reaches structure.Assuming that seabed
There are N layers of sedimentary (see Figure 10), the n-th layer sedimentary velocity of sound, density, decaying and thickness are respectively cbn、ρbn、αbnWith hn, n-th layer
It is t at the time of the back wave at interface reaches hydrophone in sedimentaryn.So the n-th layer sedimentary velocity of sound and thickness are full therebetween
Foot formula:
2hn=(tn+1-tn)cbn (9)
Deposit thickness can be characterized with the sedimentary velocity of sound with an amount using above formula, reduce the dimension of inverting variable
Degree, can be improved the efficiency of inverting to a certain extent.
It has been determined that seabed layered structure may be selected by corresponding seafloor model to establish inverse model.Amount to inverting
For the velocity of sound of sedimentary and substrate, density and decaying.Refutation process is exactly the vertical coherence function C for calculating model12(ω) and
Observe obtained vertical coherence functionIt is matched, when objective function is optimal, inverting obtains optimal seabed ginseng
Number vector.Objective function FcostIs defined as:
Wherein theoretical noise field vertical coherence function C12(ω) is calculated by formula (7).Survey noise field vertical coherence letter
NumberSolution procedure is as follows: setting the vertical vibration velocity signal time sequence of noise field of No.1 hydrophone and the acquisition of No. two hydrophones
Respectively x1(t) and x2(t), data are divided into N sections, every segment data is Δ T seconds long, each segment noise signal after equal part
It is respectively X that Frequency Domain Solution is obtained after Fourier transformation1(ω,ΔTn) and X2(ω,ΔTn), in order to reduce noise source stochastic behaviour pair
The influence of calculated result is averaged the noise correlation coefficients after N sections of normalization, finally obtains and survey noise between two hydrophones
Field coherent function
F under one group of bottom parameters is obtained using Genetic algorithm searchingcostWhen minimum, this group of C12(ω) corresponding bottom parameters
The as obtained submarine acoustic parameter of inverting.
2. simulation analysis
Two kinds of Oceanic waveguides are emulated, I class Oceanic waveguide is semo-infinite seabed, and II class Oceanic waveguide is the sea for having sedimentary
Bottom.Two kinds of waveguide seabeds sound parameter discussion section and true value be shown in Table 1.The water body velocity of sound is 1500m/s, and Hai Shen 34m, two connect
It receives hydrophone and is located at 27m and 30m.The incoherent noise source of intensity is evenly distributed on the infinity under sea in 0.1m depth
In plane, the frequency of sound wave bandwidth range of emulation is 100Hz-2500Hz.
1 Parameter discussion section of table and emulation true value
What Figure 11 was provided is that the more way arrival of theory extracted in the waveguide of semo-infinite seabed with two vertical velocity hydrophones are tied
Structure.Only have substrate echo there is no sedimentary echo as we can see from the figure, so the waveguide of semo-infinite seabed should be selected to carry out
Inverting.It is semo-infinite seabed that table 2, which gives practical seabed, using seafloor model (the seabed mould chosen in inverse model of adaptation
Type and practical seafloor model are identical) with using mismatch seafloor model (seafloor model chosen in inverse model and practical seabed
Model is not identical) the obtained submarine acoustic parameter of inverting.Practical semo-infinite Bottom sound speed is 2000m/s, with the seabed mould of mismatch
The submarine sedimentary strata velocity of sound and the substrate velocity of sound that type inverting obtains are respectively 2004.5m/s and 2325.0m/s.The deposition that inverting obtains
Layer parameter and the practical semo-infinite substrate velocity of sound are relatively.
2 semo-infinite seabed waveguide of table matching seafloor model and mismatch seafloor model inversion result
Usually our invertings the purpose of sound parameter be that the ground sound parameter obtained with inverting carries out sound field forecast.Figure 12 pairs
Than the sound field of ground sound Parameters Forecasting obtained with mismatch seafloor model inverting and the sound field forecast with true bottom parameters, emulation
The frequency of sound wave of middle selection is 100Hz, and sound source depth and reception depth are respectively 10m and 20m.It can be seen that practical seabed is
Semo-infinite seabed, the sound field forecast with the bottom parameters that mismatch model inverting obtains is within the scope of 0-50km and realistic acoustic field
There are obvious differences.
For II class waveguide, it will be apparent that there are two seabed involuting waves to reach structure, and one is interface echo in sedimentary, reaches
Moment is 0.0073s, and one is interface echo under sedimentary, arrival time 0.0095s.So when to II class waveguide inverting
The double-deck seafloor model should be selected to carry out inverting, it is assumed that the sedimentary velocity of sound is cb1, then the thickness h of sedimentary1=0.0011cb1。
Table 3 gives practical seabed as the double-deck seabed, is obtained using adaptation seafloor model with using the inverting of mismatch seafloor model
The submarine acoustic parameter arrived.The true submarine sedimentary strata velocity of sound and the substrate velocity of sound are respectively 1800m/s and 2000m/s.Selection is lost
The Bottom sound speed that the seafloor model inverting matched obtains is respectively 1830.3m/s and 1805.9m/s.It can be seen that the double-deck seabed is worked as
The velocity of sound of Bottom sound speed that the inverting of semo-infinite seabed obtains and practical submarine sedimentary strata is done relatively, this is because to noise field
It is the submarine surface velocity of sound that vertical coherence structure, which plays mainly influence, so bottom parameters that inverting obtains and practical submarine sedimentary strata
Parameter relatively.
What Figure 14 was provided is that the Acoustic Wave Propagation of the ground sound Parameters Forecasting obtained with mismatch model inverting and true propagation are damaged
Lose comparison.The ground sound parameter obtained as we can see from the figure with mismatch model inverting will lead to the sound field forecast result of mistake, most
Big difference can reach 35dB.Therefore it is necessary for selecting correct seafloor model to carry out inverting.
Table 3 double-deck seabed waveguide matching seafloor model and mismatch seafloor model inversion result
3. conclusion
The velocity of sound of submarine surface can only be obtained as a result, the base of deeper can not be obtained by selecting the seafloor model of mistake to carry out inverting
The bottom velocity of sound.And sound field is calculated using the ground sound parameter that mismatch model inverting obtains and will lead to the sound field forecast result of mistake.This
Invent the substep inversion method that provides can guarantee the seafloor model selected in inverting and practical seafloor model be it is matched, effectively
Ground improves the accuracy of inversion result.
Specific embodiment:
Figure 15 is the Bottom sound speed substep inversion method flow chart based on double vector hydrophones, is embodied as follows: to two
A received time-domain signal of vector hydrophone does inversefouriertransform and obtains the sound pressure signal of each Frequency point, then to frequency domain sound
Pressure signal does cross-correlation and obtains point-to-point transmission noise field cross-spectral density function, finally does normalized to cross-spectral density function and obtains
The measured result of noise field vertical coherence function；Anti- Fourier is to the vertical vibration velocity signal cross-spectral density function of two o'clock noise field to become
It changes extraction point-to-point transmission mostly way and reaches structure, mostly reach whether structure decision seabed has layered structure and each deposition on the way using difference
Then relationship between thickness degree and the velocity of sound selects corresponding seafloor model, utilize theoretical and actual measurement noise field coherent function
Cost function is constructed, noise field coherent function notional result and actual measurement under a certain group of parameter are searched for using niche genetic algorithm and tied
Fruit matching is optimal, then this group of parameter is the ground sound parameter that inverting obtains.
Claims (1)
1. a kind of Bottom sound speed substep inversion method based on double vector hydrophones, it is characterised in that steps are as follows:
Step 1 establishes the sound field Green's function extraction model based on the vertical vibration velocity signal of noise field:
Acoustic pressure cross-spectral density function:
Vertical vibration velocity cross-spectral density function:
Acoustic pressure time-space correlation function:
Vertical vibration velocity time-space correlation function:
Wherein: q2For noise source spectral intensity, k2For with reference to wave number, um(z) and u 'mIt (z) is m rank eigenfunction at depth z
Value and its derivative, kmFor m rank characteristic value, R0For the radius of noise source disk, ρ and c are respectively water body density harmony at sound source
Speed,Indicate inversefouriertransform, ω is angular frequency, and τ is time delay；Acoustic pressure/vertical vibration velocity time-space correlation function is proportional to sound field
Time domain Green function, so each relevant peaks correspond to different more way arrival times in time-space correlation function, it is different by extracting
Multipath structure arrival time can obtain the relational expression in the layered structure and every layer of sedimentary in seabed between the velocity of sound and thickness；
Step 2 establishes the Bottom sound speed substep inverse model based on double vertical velocity hydrophones:
Normalized is done to two spot noise cross-spectral density functions and obtains theoretical noise field vertical coherence function C12(ω):
Survey noise field vertical coherence functionSolution procedure is as follows:
Wherein: N is data snapshot sum, and Δ T is each snapshot data length, X1(f,ΔTn) and X2(f,ΔTn) it is respectively first
The Frequency Domain Solution of a hydrophone and the vertical vibration velocity signal of n-th of snapshot noise field of second hydrophone acquisition；
Step 3 provides the Bottom sound speed inverse model based on noise field vector signal vertical coherence characteristic:
Wherein: FcostFor cost function, N is the frequency point sum considered, Γ andRespectively theoretical and actual measurement noise field acoustic pressure/hang down
Straight vibration velocity coherent function；Characteristic value in Γ and eigenfunction equivalent need by seawater parameters,acoustic, submarine acoustic parameter and
Receiver parameters,acoustic, which is input in propagation model, to be calculated；
The layered structure in seabed and the relationship of Bottom sound speed and thickness can be obtained by step 1, if seabed is semo-infinite sea
Bottom, then the bottom parameters collection Ω to inverting can be expressed as Ω=[cb,ρb,αb], if there are K layers of sedimentary in seabed,
It can so be expressed as to the bottom parameters collection Ω of inverting
Ω=[cb1,ρb1,αb1,hb1…cbK,ρbK,αbK,hbK,cbK+1,ρbK+1,αbK+1]；
Wherein K+1 layers of expression semo-infinite basal layer
One group of parameter is searched in given submarine acoustic parameter search space Ω using niche genetic algorithmSo that cost letter
Number FcostMinimum, then this group of parameter is true bottom parameters.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110411480A (en) * | 2019-08-27 | 2019-11-05 | 哈尔滨工程大学 | A kind of underwater motor platform acoustic navigation error prediction method under complexity marine environment |
| CN111580048A (en) * | 2020-05-09 | 2020-08-25 | 中国科学院声学研究所 | Broadband sound source depth estimation method using single-vector hydrophone |
| CN112729532A (en) * | 2021-01-05 | 2021-04-30 | 北京耘科科技有限公司 | Method, device, equipment and medium for acquiring near-field transfer function of shallow sea motion sound source |
| CN113011276A (en) * | 2021-02-25 | 2021-06-22 | 中国科学院声学研究所 | pseudo-Green function passive extraction method based on radiation noise of opportunity ship |
| CN113009419A (en) * | 2021-02-25 | 2021-06-22 | 中国科学院声学研究所 | Target depth estimation method based on frequency domain cross-correlation matching |
| CN113640806A (en) * | 2020-04-27 | 2021-11-12 | 中国科学院声学研究所 | Sedimentary stratum acoustic characteristic obtaining method and system based on multiple sonar equipment |
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Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4405036A (en) * | 1980-12-11 | 1983-09-20 | Marathon Oil Company | Seafloor velocity and amplitude measurement apparatus method |
| US4982375A (en) * | 1989-11-13 | 1991-01-01 | The United States Of America As Represented By The Secretary Of The Navy | Acoustic intensity probe |
| CN101539597A (en) * | 2009-04-29 | 2009-09-23 | 哈尔滨工程大学 | Multi-target method for distinguishing radiation noises having same frequency band |
| CN103293515A (en) * | 2012-11-19 | 2013-09-11 | 西北工业大学 | Ship and warship line spectrum noise source longitudinal distribution characteristic measuring method |
| CN103605108A (en) * | 2013-07-29 | 2014-02-26 | 哈尔滨工程大学 | High-precision remote direction estimation method of acoustic vector array |
| CN104091048A (en) * | 2014-06-19 | 2014-10-08 | 哈尔滨工程大学 | Underwater target depth measuring method adopting passive vertical double-vector hydrophones |
| CN105589066A (en) * | 2015-12-14 | 2016-05-18 | 西北工业大学 | Method for estimating parameters of underwater constant-speed vehicle based on vertical vector array |
| CN105631194A (en) * | 2015-12-20 | 2016-06-01 | 西北工业大学 | Method for inversing sea-bottom attenuation coefficient by using modal dispersion curve energy difference |
| CN105929385A (en) * | 2016-04-06 | 2016-09-07 | 山东省科学院海洋仪器仪表研究所 | Bi-hydrophone LOFAR (low frequency analysis record) spectrogram analysis-based target depth distinguishing method |
| CN106441553A (en) * | 2016-09-30 | 2017-02-22 | 中国海洋大学 | Acoustic monitoring system and method based on ambient sea noise |
| CN106568496A (en) * | 2016-11-09 | 2017-04-19 | 哈尔滨工程大学 | Real-time transmission multivariate vector hydrophone array subsurface buoy system |
| CN106908520A (en) * | 2017-03-02 | 2017-06-30 | 山东科技大学 | Low-and high-frequency sediment parameter measurement instrument and sediment measurement method of parameters |
| RU2646528C1 (en) * | 2016-12-07 | 2018-03-05 | Федеральное государственное бюджетное учреждение науки Институт физики Земли им. О.Ю. Шмидта Российской академии наук (ИФЗ РАН) | Method of searching for mineral resources on the shelf of seas coated by ice |
| CN108181651A (en) * | 2017-12-25 | 2018-06-19 | 西北工业大学 | A kind of deep-sea geoacoustic inversion method based on reliable acoustic path |
| CN108845287A (en) * | 2018-04-09 | 2018-11-20 | 哈尔滨工程大学 | The single vector hydrophone coherent source Fast Azimuth estimation method of niche genetic algorithm |
| CN109000779A (en) * | 2018-07-12 | 2018-12-14 | 青岛中海潮科技有限公司 | A kind of ocean acoustic propagational reliability model Rapid matching system |
-
2018
- 2018-12-25 CN CN201811590470.2A patent/CN109489799B/en not_active Expired - Fee Related
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4405036A (en) * | 1980-12-11 | 1983-09-20 | Marathon Oil Company | Seafloor velocity and amplitude measurement apparatus method |
| US4982375A (en) * | 1989-11-13 | 1991-01-01 | The United States Of America As Represented By The Secretary Of The Navy | Acoustic intensity probe |
| CN101539597A (en) * | 2009-04-29 | 2009-09-23 | 哈尔滨工程大学 | Multi-target method for distinguishing radiation noises having same frequency band |
| CN103293515A (en) * | 2012-11-19 | 2013-09-11 | 西北工业大学 | Ship and warship line spectrum noise source longitudinal distribution characteristic measuring method |
| CN103605108A (en) * | 2013-07-29 | 2014-02-26 | 哈尔滨工程大学 | High-precision remote direction estimation method of acoustic vector array |
| CN104091048A (en) * | 2014-06-19 | 2014-10-08 | 哈尔滨工程大学 | Underwater target depth measuring method adopting passive vertical double-vector hydrophones |
| CN105589066A (en) * | 2015-12-14 | 2016-05-18 | 西北工业大学 | Method for estimating parameters of underwater constant-speed vehicle based on vertical vector array |
| CN105631194A (en) * | 2015-12-20 | 2016-06-01 | 西北工业大学 | Method for inversing sea-bottom attenuation coefficient by using modal dispersion curve energy difference |
| CN105929385A (en) * | 2016-04-06 | 2016-09-07 | 山东省科学院海洋仪器仪表研究所 | Bi-hydrophone LOFAR (low frequency analysis record) spectrogram analysis-based target depth distinguishing method |
| CN106441553A (en) * | 2016-09-30 | 2017-02-22 | 中国海洋大学 | Acoustic monitoring system and method based on ambient sea noise |
| CN106568496A (en) * | 2016-11-09 | 2017-04-19 | 哈尔滨工程大学 | Real-time transmission multivariate vector hydrophone array subsurface buoy system |
| RU2646528C1 (en) * | 2016-12-07 | 2018-03-05 | Федеральное государственное бюджетное учреждение науки Институт физики Земли им. О.Ю. Шмидта Российской академии наук (ИФЗ РАН) | Method of searching for mineral resources on the shelf of seas coated by ice |
| CN106908520A (en) * | 2017-03-02 | 2017-06-30 | 山东科技大学 | Low-and high-frequency sediment parameter measurement instrument and sediment measurement method of parameters |
| CN108181651A (en) * | 2017-12-25 | 2018-06-19 | 西北工业大学 | A kind of deep-sea geoacoustic inversion method based on reliable acoustic path |
| CN108845287A (en) * | 2018-04-09 | 2018-11-20 | 哈尔滨工程大学 | The single vector hydrophone coherent source Fast Azimuth estimation method of niche genetic algorithm |
| CN109000779A (en) * | 2018-07-12 | 2018-12-14 | 青岛中海潮科技有限公司 | A kind of ocean acoustic propagational reliability model Rapid matching system |
Non-Patent Citations (5)
| Title |
|---|
| JIANBO ZHOU: "《A spatial correlation model for the horizontal non-isotropic ocean ambient noise vector field》", 《JOURNAL OF LOW FREQUENCY NOISE VIBRATION & ACTIVE CONTROL》 * |
| JIANBO ZHOU: "《The effect of sea-surface roughness on ambient noise vertical directionality in shallow water waveguide》", 《2016 IEEE/OES CHINA OCEAN ACOUSTICS (COA)》 * |
| ZHOU J: "《Extracting the time domain Green"s function from ocean ambient noise using acoustic》", 《JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA》 * |
| 朱良明: "《浅海声压与垂直振速垂直相关特性研究》", 《2014年中国声学学会全国声学学术会议》 * |
| 郭新毅: "《海洋环境噪声研究发展概述及应用前景》", 《物理》 * |
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