98 results about "Sound speed profile" patented technology

The invention provides a system for improving positioning precision under a complex underwater acoustic channel and an optimization method, and relates to the field of underwater positioning. The system for improving the positioning precision under the complex underwater acoustic channel comprises a time delay estimation module, a sound velocity profile data module, a sound ray correction module, a slope distance value precision module and a precision improvement module, and the time delay estimation module is mainly used for obtaining more accurate time delay data; the sound velocity profile data module is mainly used for acquiring sound velocity profile data of a positioning area. According to the method, a real sound ray path is estimated by using a sound ray correction method, measurement errors of bubbles in water, sound velocity change and position and propagation time are considered, the positioning precision is further improved, and the comprehensive optimization method enables the system to accurately reflect the real position of a target in a complex underwater environment, so that the positioning accuracy is improved. The overall performance of underwater target positioning is remarkably improved, and the actual requirement of high-precision positioning is met.

The invention relates to the technical field of beam fusion, and discloses an irregular water area underwater topographic surveying and mapping method based on multi-beam fusion, which comprises the following steps: acquiring multi-voyage sounding data of a target irregular water area by using a multi-platform multi-beam sounding system such as a coastal patrol ship and an unmanned surveying ship, and performing sound velocity profile correction, attitude correction and tide level reduction to obtain a target irregular water area; unifying to the same space-time reference and plane rectangular coordinate system, and constructing an initial underwater terrain digital elevation model in an irregular water area range by adopting Gaussian weighted interpolation; defining an influence area by taking a hydraulic structure as a center, decomposing a local terrain into a background terrain and a scouring residual error, performing polar coordinate conversion and angular terrain spectrum analysis in the influence area, and calculating an axisymmetric form dominance index of the scouring pit; and constructing a topographic form shaping factor based on the axisymmetric form dominance index of the scouring pit, the maximum scouring depth and the influence radius, performing frequency domain modulation on the Fourier coefficient, and reconstructing the corrected local topography to obtain a final underwater topography DEM.

The invention discloses a low-frequency sound propagation loss forecasting method suitable for a polar region sea area, and the method comprises the steps: building a two-dimensional ice layer model of a forecast sea area according to remote sensing data based on the setting that sea ice of the polar region sea area is a uniform elastic medium; calculating hydrological conditions of the ocean sound channel of the polar sea area; establishing a forecast sea area two-dimensional seabed model according to the seabed topography sediment database; an under-ice sound field model is constructed based on a three-dimensional cylindrical coordinate system, sound pressure from unit intensity sound sources with different sizes and depths to a receiving point in a forecast sea area is calculated through a frequency domain finite element method in combination with a PML technology, and sound propagation loss of a needed position is obtained through calculation. According to the method, the application limitation of traditional ray and normal wave theories under complex boundary conditions is broken through through a finite element method, a synergistic effect mechanism of actual ice layer parameter space change, submarine topography fluctuation and sound velocity profile gradient characteristics is systematically analyzed, and sound field modeling is more accurately carried out on different ice layers and submarine topographies in the Chukong sea region all year round; the influence of sound wave propagation is simulated.

The invention belongs to the technical field of underwater target detection, and discloses an underwater target depth coherent estimation method and system, and the method comprises the steps: receiving a single snapshot signal radiated by a target through a sensor array carried by an underwater carrier, and constructing a potential normal wave orthogonal mode space of a sound field under the condition that a sound velocity profile is known, estimating normal wave parameters (namely normal wave horizontal wave number and vertical modal function) and depth-related modal characteristics (namely modal amplitude) by using the sparsity of the sound field projected in the orthogonal modal space as a constraint, and coherently estimating the depth of the underwater target by using a modal polarity-based search method. According to the method, target depth coherent estimation is realized in a marine environment with unknown seabed sediment by using a single frequency component in a single snapshot noise signal radiated by the target, the accuracy of polarity estimation is improved by using a theoretical depth ambiguity function learned by the KAN network, and the method can be used for underwater target positioning, identification and the like. The method is suitable for carrier platforms such as vertical array subsurface buoys and vertical array buoys.

The invention particularly relates to a deep sea reliable sound path long baseline robust positioning method based on iterative equivalent sound velocity correction, which comprises the following steps: firstly, selecting a coordinate origin, and delimiting a positioning area by taking the coordinate origin as a center; a sonar receiving array is distributed to a proper position, a hydroacoustics numerical calculation ray model is utilized to establish a sound field model according to data such as a sound velocity profile, a target sound source depth and a horizontal distance range, and an equivalent sound velocity table is obtained. Then, inputting an initial equivalent sound velocity vector and an initial relative propagation time vector, and obtaining initial target position estimation by using a hyperbolic intersection method; next, the equivalent sound velocity and the target position are updated through iteration, and an adaptive adjustment item is introduced, so that the convergence and robustness of the algorithm are improved; and finally, judging whether iteration is terminated or not by utilizing a maximum likelihood error function. The method combines the hyperbolic intersection method to efficiently solve and adaptively adjust items, is high in positioning precision, is high in calculation efficiency, and is suitable for underwater real-time high-precision positioning tasks.

The invention relates to an unmanned ship area coverage search path planning method, which comprises the following steps of: 1, calling environmental data such as submarine topography and hydrological environment of a task area by utilizing an environmental database, dispersing a sea area into a plurality of grids by adopting a grid method, and drawing a sounding map and a sound velocity profile map of the area, the motion space of the unmanned ship is simplified into a two-dimensional plane, under-actuated and high-inertia motion characteristics of the unmanned ship are considered, the unmanned ship is regarded as vector points with the direction and the speed, meanwhile, speed constraint is achieved by limiting the upper limit and the lower limit of the speed, and steering constraint is achieved by setting the maximum steering angle in unit time. According to the invention, the convergence capability, robustness and adaptability of a path planning algorithm are effectively improved; and the coverage efficiency of the target area is effectively improved.

The invention relates to the technical field of marine acoustics, in particular to a multi-criterion selection method for a complex marine environment sound field calculation model, which comprises the following steps: S1, acquiring environmental parameters of a target sea area; s2, judging whether the terrain is horizontally changed, whether the seabed sediment is horizontally changed and whether the sound velocity profile gradient is horizontally changed according to the environmental parameters, if the terrain is horizontally unchanged, the seabed sediment is horizontally unchanged and the sound velocity profile gradient is horizontally unchanged, judging that the sound field environment level is unchanged, otherwise, judging that the sound field environment level is changed; and S3, selecting a model according to whether the sound field environment level is changed or not, if the sound field environment level is unchanged, selecting a shallow sea smooth average sound field model or a deep sea generalized phase integral model WKBZ according to a sea depth threshold value, and if the sound field environment level is changed, selecting a parabolic equation model RAM or a ray model BELLHOP according to a terrain type and a frequency threshold value. Through a multi-criterion selection method, scientization and engineering of complex marine environment sound field calculation model selection can be realized.

The invention relates to an underwater acoustic communication cooperative control method and device based on multiple parameters, equipment and a storage medium. The method comprises the steps of obtaining environmental parameters, calculating basic sound velocity data based on the environmental parameters, determining a sound velocity profile formula corresponding to the basic sound velocity data, correcting the basic sound velocity data based on the sound velocity profile formula to obtain corrected sound velocity, and determining the distance between an underwater node and a water surface base station. The method comprises the following steps: acquiring the corrected sound velocity, the distance, the data volume and the residual energy to be transmitted of an underwater node, inputting the corrected sound velocity, the distance, the data volume and the residual energy into a pre-constructed communication optimization model to obtain a target communication frequency and a target transmitting power, and controlling the underwater node to communicate with a water surface base station based on the target communication frequency and the target transmitting power. The communication efficiency can be improved, the communication conflict risk is reduced, the node endurance time is prolonged, and the communication stability and reliability are improved.

The invention relates to the technical field of underwater sound detection, in particular to a broadband sound source depth estimation method matched with a deep sea sound velocity profile, and the method comprises the steps: obtaining a frequency-vertical arrival angle spectrum for an underwater broadband sound source in a mode of carrying out broadband beam forming processing on a receiving sound field of a vertical linear array; analyzing the characteristics of the interference period of the frequency-vertical arrival angle spectrum by using a layered medium model, and establishing a corresponding relation between the interference period and the sound source depth; based on the corresponding relation between the interference period and the sound source depth, mapping the frequency-vertical arrival angle spectrum to a glancing angle-depth domain to form an ambiguity plane of the sound source depth; and based on the ambiguity plane, depth estimation of the underwater broadband sound source is realized. According to the method, accurate and rapid depth estimation of the underwater broadband sound source can still be realized at a long distance, and meanwhile, the method has good environmental adaptability.

The application discloses a kind of sea surface convergence zone parameter calculation method and system based on sound propagation loss, method includes: propagation loss acquisition step: according to horizontal sound velocity profile variation data, seabed topography variation data and seabed sediment parameter, propagation loss data is obtained by sound propagation model;Convergence path acquisition step: based on propagation loss data, convergence path data and convergence zone quantity parameter are obtained by constant false alarm processing technique and connected domain technique;Convergence zone center point acquisition step: based on convergence path data, the position of convergence zone center point is determined by constant false alarm technique;Convergence zone boundary acquisition step: based on the gradient variation characteristics of convergence zone center point position combined with propagation loss data, the range boundary of the range boundary of convergence zone center point position is determined, and the detection and identification of underwater acoustic field convergence zone under complex marine environment are realized by the application.

The invention relates to a regional ocean sound propagation field millisecond-level prediction method based on a deep neural network, and the method comprises the steps: constructing two factors which have the greatest influence on a sound propagation field for a target region: a sound velocity profile and a terrain; an environment information data set of an area sound propagation field is constructed by constructing an annual sound velocity profile of a target area node and building a large number of two-dimensional terrain models by extending around the node by 360 degrees, and the sound propagation fields of the area under different environment conditions are calculated by using a traditional sound field calculation model to serve as a training set; feature simplification parameters of the sound velocity profile and the terrain in each environment sample are extracted to serve as guide information of a corresponding sound propagation field, and a deep neural network is built to learn distribution rules of the sound propagation fields under different environment conditions in the area; and finally, the trained model can quickly predict the corresponding sound propagation field in the region according to different environmental condition characteristic batches.

The invention provides an ocean sound field correlation calculation method, device and equipment and a readable storage medium. The method comprises the steps of setting sea depth, a sound velocity profile, position parameters of a sound source and position parameters of each array element in a receiving array in a Bellhop ray model; time delay and amplitude coefficients of waves of a target type from the sound source to each array element are calculated based on a Bellhop ray model, and the target type is determined according to a sound area where the array element is located; calculating to obtain a time domain signal received by each array element according to the time domain signal emitted by the sound source and the time delay and amplitude coefficient of the wave of the target type from the sound source to each array element; and calculating the correlation coefficient of each array element relative to the target array element according to the time domain signals received by each array element and the target array element. According to the invention, the Bellhop ray model is used to accurately calculate the time delay and amplitude coefficient of the specific sound wave propagation in the ocean, the analysis of the ocean sound field correlation is transferred from the frequency domain to the time domain, and the calculation efficiency and accuracy of the ocean sound field correlation calculation are improved.

The present application relates to a kind of multi-sensor wideband sound source positioning method suitable for deep-sea reliable sound path environment, utilize the same sound source D-SR time delay measurement value observed by deep-sea large depth multi-sensor to carry out three-dimensional positioning to sound source.In the first stage, based on the position of each sensor, depth, observed D-SR time delay and water body sound velocity profile information, a matrix and a vector are constructed, there is a linear relationship between the two and the position of sound source, the least square method is used to solve this linear relationship, obtain the estimation result of the two-dimensional position of sound source, based on two-dimensional position estimation result, the depth estimation result of sound source is obtained using depth solution formula;In the second stage, based on the three-dimensional position of sound source estimated in the first stage, the D-SR time delay value of the position of each sensor is predicted, then an auxiliary variable matrix is constructed, and new sound source two-dimensional horizontal position estimation result is obtained according to the rule of auxiliary variable estimator (IVE), and finally the final sound source depth estimation result is obtained according to depth solution formula.

The invention belongs to the technical field of underwater acoustic communication, and relates to an ocean sound velocity profile prediction method based on fusion weighted EOF-LSTM, and the method comprises the steps: constructing a historical sound velocity profile data matrix; based on the year difference and the month difference with the target year and month, obtaining a comprehensive time distance, and constructing a Gaussian weighting function; performing normalization processing, calculating a weighted average sound velocity profile, extracting a spatial change mode of the sound velocity profile, realizing dimension reduction and feature extraction, and calculating a principal component; constructing a time window sample by using the principal component time sequence; using LSTM network training to obtain a principal component prediction value, reconstructing a sound velocity profile, and obtaining a target year monthly sound velocity profile prediction value; and extracting a real sound velocity profile value of the target year, and performing error comparison with the predicted value. And a weighting function is constructed for the average sound velocity profile for weighting, an optimal time step length is searched for LSTM input data, an error is used as a reference iterative optimization weight parameter, and effective reduction of a prediction error is realized.

The utility model provides a support frame for a sound velocity profiler, and relates to the technical field of sound velocity profilers, the support frame comprises a sound velocity profiler body and a mounting frame, and the sound velocity profiler body is mounted in the middle of the inner side of the mounting frame; the two ends of the inner side of the mounting frame are both provided with balancing weights, the two sets of balancing weights are both fixedly mounted on the inner wall of the mounting frame, the two sets of balancing weights are arranged on the two sides of the outer surface of the sound velocity profiler body respectively, the side ends of the balancing weights are connected with clamping rings, and the clamping rings are used for clamping and fixing the sound velocity profiler body. According to the utility model, the two groups of balancing weights are mounted in the mounting frame to increase the balance weight, so that the sound velocity profiler body is lowered to the deep position of the seabed for detection work, and the gravity applied by the two groups of balancing weights can relieve the fluctuation of the sound velocity profiler body caused by the flowing of seawater; therefore, the stability and accuracy of the sound velocity profiler body during detection work in seawater are enhanced.

The present application discloses a method, device, equipment and medium for determining the distance of a deep-sea sound propagation convergence zone, belonging to the field of marine acoustic technology. The method comprises: obtaining the water depth data and corresponding sound speed at the boundary of each layer of seawater in the target sea area, and constructing a three-layer broken line model of the sound speed profile; constructing a first circular arc trajectory group and a second circular arc trajectory group based on the three-layer broken line model, the sound source position of the target sea area and Snell's law; determining the first critical sound ray trajectory and the second critical sound ray trajectory of the deep-sea convergence zone of the target sea area based on the first circular arc trajectory group and the second circular arc trajectory group; determining the convergence zone distance of the target sea area based on the first critical sound ray trajectory and the second critical sound ray trajectory. This method improves the calculation efficiency of the deep-sea convergence zone distance.

This invention discloses a sound velocity profile assimilation and inversion method and system based on dual physical data driving. The method includes: performing adaptive observation and sparse characterization of the sound propagation path to obtain the sparse characterization results; performing long-term noise cross-correlation calculation and passive time delay self-calibration to obtain the virtual sound source arrival time series after absolute time delay reference correction; performing constraint verification through a physical-data dual-driven, dual-stream coupled generative inversion network; acquiring a broadband electromagnetic response time series and performing cross-medium electromagnetic-acoustic joint inversion constraints to obtain a strongly constrained calibrated full-depth sound velocity profile; and performing ensemble Kalman filtering assimilation and uncertainty propagation based on POD order reduction. This invention can quantify the uncertainty of the inversion results. As a sound velocity profile assimilation and inversion method and system based on dual physical data driving, this invention can be widely applied in the field of underwater acoustic engineering technology.

The invention provides a method and a system for calculating multi-path arrival time under a deep sea fluctuating sea surface. The method comprises the following steps: generating a one-dimensional fluctuating sea surface as a sea surface parameter through a Monte Carlo method; using a bubble layer model to correct the sound velocity profile as an environmental parameter; and inputting the sea surface parameters and the environmental parameters into the ray model, and outputting multi-path arrival time data under the fluctuating sea surface. The method has the advantages that the defect that an existing traditional calculation method for the multi-path arrival time under the fluctuating sea surface does not consider the fluctuating sea surface and near sea surface bubble mixing layer factors can be overcome, and the influence of sea surface storm waves on the multi-path arrival time is more comprehensively considered.

The invention relates to the technical field of surveying and mapping positioning, in particular to a high-precision offset positioning sounding auxiliary system and a use method, and the system comprises a positioning sensing module, an attitude and offset measurement module, a sound velocity profile measurement module, a data processing unit, and a communication and storage module. And the data of the positioning sensing module, the attitude and offset measurement module and the sound velocity profile measurement module are transmitted to the data processing unit through the communication and storage module for fusion processing. The system is suitable for high-precision sounding scenes of complex water areas such as near banks, ports, channels, underwater obstacle dense areas and the like; the problem that the absolute coordinate precision of a depth point is insufficient due to multi-source errors in traditional depth sounding positioning is solved.

The invention discloses a sound velocity profile measuring device and method based on an offshore fixed platform, and belongs to the technical field of marine environment monitoring, the device comprises a hydrological winch, a self-tensioning winch and a central control unit which are arranged on the offshore fixed platform, and a steering wheel arranged on the seabed, the hydrological winch is connected with and controls the lifting stroke of the survey equipment through an optical cable integrated with an electric signal transmission function, the self-tensioning winch is connected to the survey equipment through a geological cable after passing through a seabed steering wheel, and the central control unit coordinates and controls the two winches to maintain constant set tension. According to the invention, through the strategy of cooperative operation of double winches and seabed steering anchoring, the problems of difficult cable path control, large tension fluctuation, unstable equipment attitude and the like when full-sea-depth profile measurement is carried out from a fixed platform are solved, high-reliability sound velocity profile observation is realized, and the quality of measured data is improved.

The invention relates to an integrated navigation precision improvement method based on fused hydrological information, which belongs to the technical field of inertial navigation, and comprises the following steps: S1, based on hydrological information of a target navigation sea area, calculating to obtain a sound velocity profile of the target navigation sea area and wave beam angles of each water layer of the target navigation sea area; s2, based on the sound velocity profile of the target navigation sea area and each water layer beam angle, obtaining a corrected Doppler measurement speed; s3, compensating the corrected Doppler measurement speed based on the beam incident angle after equivalent refraction to obtain a compensated Doppler measurement speed; and S4, fusing the compensated Doppler measurement speed with the inertial navigation speed to obtain a corrected navigation calculation result of the ship or the underwater vehicle. According to the invention, the hydrological environment data and the inertial navigation data are fused, so that the position precision and reliability of the ship or the underwater vehicle during long-time autonomous navigation are greatly improved.

The present invention discloses a method for dimensionality reduction representation of a sound velocity profile using Rossby wave modes, which relates to the field of dimensionality reduction of sound velocity profiles and includes the following steps: quantifying the stratified characteristics of the target sea area; calculating the Rossby wave modes based on the Brent-Vaisala frequency to obtain the first five-order Rossby wave modes; converting the 0th to 5th order Rossby wave modes into sound velocity perturbation modes based on the temperature gradient of the stratified temperature profile; obtaining the coefficients of each sound velocity perturbation mode during the sound velocity profile reconstruction process; representing and reconstructing the sound velocity profile using the coefficients in the sound velocity profile reconstruction process. This method can quickly reconstruct any sound velocity profile that conforms to physical laws, providing support for ensuring the detection performance of the sonar system. This method has very low sample requirements and can even be implemented by relying on global ocean data products such as WOA23 in the absence of historical measurement samples of the sea area.

The invention discloses an acoustic chromatography flow field and temperature synchronous assimilation method based on acoustic propagation path tracking, and belongs to the technical field of acoustic chromatography flow field assimilation, and the method comprises the following steps: S1, obtaining acoustic propagation path information: collecting temperature and salinity profile data of a target sea area, calculating to obtain a background sound velocity profile of a target sea area based on a sound velocity empirical formula by using temperature, salinity and depth hydrological data, and obtaining an accurate sound propagation path between each sound tomography observation station pair of the target sea area by using a sound propagation model; s2, establishing a flow velocity observation operator; s3, establishing a temperature observation operator; and S4, establishing a temperature and flow velocity synchronous assimilation observation operator. According to the method, the problems of small application range and low assimilation precision of the existing acoustic tomography flow field assimilation technology can be solved, and the flow field and the temperature field are synchronously assimilated on the basis of the acoustic propagation path tracking technology, so that the precision of the flow field and the temperature field is synchronously improved.

This invention relates to the field of underwater acoustic positioning and topographic detection in marine environments, providing a rapid calculation method and system for the incident angle and propagation time of a direct sound ray between two points. The method includes: dividing seawater into layers based on a sound velocity profile; adaptively dividing the incident angle interval according to a preset comprehensive error threshold; calculating the horizontal displacement and propagation time of the sound ray corresponding to different incident angles; and constructing an interpolation coefficient table through third-order polynomial fitting; combining the piecewise displacement of the water depth intervals where the sound ray originates and terminates, obtaining the third-order polynomial fitting coefficients of the horizontal displacement with respect to the incident angle from the polynomial interpolation coefficient table, constructing a cubic equation with respect to the incident angle, solving it using the Cardano method, and iteratively obtaining the incident angle correction value according to a preset angle error threshold; calculating the propagation time; and finally outputting the incident angle and propagation time of the sound ray. This method replaces layer-by-layer calculation with interpolation modeling, achieving high accuracy, rapid convergence, and coefficient table reuse.

This invention relates to the field of beam fusion technology and discloses a method for underwater topography mapping of irregular waters based on multi-beam fusion. The method includes: acquiring multi-voyage bathymetry data of the target irregular waters using a multi-platform multi-beam bathymetry system such as a patrol vessel or unmanned survey vessel; after sound velocity profile correction, attitude correction, and tidal level calculation, unifying the data to the same spatiotemporal reference and Cartesian coordinate system; constructing an initial underwater topography digital elevation model within the irregular water area using Gaussian weighted interpolation; delineating the influence area centered on the hydraulic structure; decomposing the local topography into background topography and scour residual; performing polar coordinate transformation and angular topographic spectrum analysis within the influence area to calculate the axisymmetric morphological dominance index of the scour pit; constructing a topography shaping factor based on the axisymmetric morphological dominance index of the scour pit, the maximum scour depth, and the influence radius; frequency-domain modulation of the Fourier coefficients; and reconstructing the corrected local topography to obtain the final underwater topography DEM.

The application discloses a kind of temperature sound velocity parameter measurement methods in ice based on rod longitudinal vibration mode inversion, belong to ice layer acoustic measurement technical field, including the following steps: S1, layout thin stick, and vibration signal is collected;S2, vibration signal is analyzed, and the resonance frequency set of thin stick longitudinal vibration is obtained;S3, construct non-uniform longitudinal vibration model, and according to the resonance frequency set of thin stick longitudinal vibration is inverted, and the thin stick Young's modulus distribution is obtained;S4, thin stick Young's modulus distribution is mapped as thin stick along the temperature distribution of axial direction, and thin stick along the temperature distribution of axial direction is regarded as the equivalent representation of ice layer along corresponding depth direction temperature distribution;S5, obtain sound velocity profile.The application excites and measures the longitudinal vibration response of thin stick in ice layer, utilizes the sensitive characteristics of thin stick longitudinal vibration mode to material parameter change under non-uniform thermal environment, realizes the inversion estimation of ice layer internal temperature distribution and sound velocity profile.

The application belongs to the technical field of sound velocity profile simplification, and discloses a sound velocity profile adaptive refinement method based on ranging error and chord inner effective area, which proposes a new measurement of chord inner area, quantifies the overall bending degree of the local curve by calculating the integral area between the curve segment and the chord, overcomes the defect that the existing method only reflects single-point deviation, and determines the effectiveness of the chord inner area by comparing the chord inner area with a threshold value to drive the adaptive refinement of the profile. On this basis, a closed-loop process driven by precision targets is established, the ranging error set by the user is taken as the input, the area difference threshold value is automatically calculated as the global constraint, the chord inner effective area criterion is used for iterative screening and feedback until the optimal simplified profile meeting the precision requirement is output, so that the leap from fuzzy empirical decision to quantitative target driving is realized, and the drawbacks of the traditional method, such as blind trial of parameters, poor shape preservation, and difficulty in balancing efficiency and precision, are fundamentally avoided.

The application relates to the technical field of wind tunnel flexible nozzle profile control devices, in particular to a continuous transonic wind tunnel liquid control flexible nozzle sound speed profile maintaining method, which comprises the following steps: calculating the total load of each support node of the flexible nozzle sound speed profile, assembling a node support mechanism to a flexible plate of the flexible nozzle, the node support mechanism comprising a mechanical locker, each node returning to a mechanical zero position and locking the mechanical locker; giving a sound speed nozzle shaping instruction of a hydraulic servo control system, unlocking the mechanical locker, and making the flexible nozzle profile run to the sound speed nozzle profile from the mechanical zero position through coordinated control of the hydraulic servo system; under the condition that the sound speed nozzle profile dynamic adjustment meets the control precision requirement, locking the mechanical locker, and the hydraulic servo system exiting the dynamic adjustment state, and the mechanical locker providing locking force to maintain the sound speed nozzle profile. The purpose of making the flexible nozzle sound speed profile more stable is achieved.

The present invention discloses a method for estimating target velocity and inverting sound velocity profiles based on modal decomposition. The method comprises the following steps: Step 1: Acquire a two-dimensional frequency domain sound field, obtain the normal wave vertical modal function through singular value decomposition, and obtain the normal wave horizontal wave number through Fourier transform; Step 2: Substitute the normal wave vertical modal function and the normal wave horizontal wave number into a modal difference equation to obtain the estimated sound velocity profile of each normal wave mode; Step 3: Set a loss function that measures the similarity between the sound velocity profiles corresponding to each normal wave mode, set a target velocity search interval, scan the target velocity search interval, and use the velocity value corresponding to the minimum loss function as the target velocity estimate. The present invention utilizes the narrowband signal radiated by the moving target to achieve target velocity estimation and sound velocity profile inversion in an unknown ocean environment.

The present invention provides a method and device for predicting seawater sound velocity profile based on BNNConvLSTM. The method comprises obtaining raw data within a preset time period of a sea area to be measured, and calculating the seawater sound velocity profile data of the sea area to be measured based on the raw data; applying a preset ConvLSTM model based on the seawater sound velocity profile data to obtain sound velocity profile prediction data of the sea area to be measured; and applying a preset BNNConvLSTM model based on the seawater sound velocity profile data to obtain a prediction interval of the sound velocity profile prediction data of the sea area to be measured within a specified confidence interval. The present invention makes full use of the spatiotemporal characteristics of the seawater sound velocity profile, designs a ConvLSTM model and a BNNConvLSTM model to respectively calculate the predicted value of the seawater sound velocity to be measured and the prediction interval within a specified confidence interval, thereby achieving a measurement of the uncertainty in the prediction caused by the variability of the marine environment.