212 results about "Sonar system" patented technology

The invention relates to the technical field of underwater detection and navigation, in particular to a sonar real-time high-precision synchronous positioning and map building optimization method based on a dynamic sliding window and inertial navigation, and the method comprises the steps: introducing a dynamic sliding window adjustment module and an inertial navigation module, the dynamic sliding window adjusting mechanism dynamically adjusts the length of a sliding window according to the operation state (such as the movement speed and the steering angular speed) of a sonar system, the real-time performance is enhanced by reducing the window in a high-dynamic environment, and the map precision is improved by enlarging the window in a low-dynamic environment. The sliding window adjustment rule is driven by output parameters of the inertial navigation module, including acceleration, angular velocity and the like, the size of the sliding window is adjusted in real time according to the motion state (such as speed and steering angular velocity) of the sonar system, and the environmental perception ability of the sonar system in a complex scene is improved.

The invention belongs to the technical field of underwater target imaging and detection, and particularly relates to a multi-source data fusion method for sonar detection positioning, which comprises a forward-looking sonar system comprising a transmitting array and a receiving array, the transmitting array is positioned above the receiving array and is used for transmitting a vertical wave beam to scan a target, and the receiving array is positioned above the receiving array and is used for transmitting a vertical wave beam to scan the target. Locking the direction of the vertical wave beam to position a target, transmitting a horizontal wave beam to carry out fan-shaped strip scanning along the direction of the vertical wave beam, then carrying out feature extraction and target imaging on each sonar echo signal, fusing the extracted multi-level target features, and then carrying out classification identification on the target features. The receiving array is used for receiving echo signals transmitted by the transmitting array, and an external interconnection connector is arranged above the transmitting array and is used for being in communication connection with display equipment for image transmission, performing multi-level information fusion processing on target characteristics from the active sonar and performing target category judgment; and the target detection and positioning precision is effectively improved.

The invention belongs to the technical field of underwater acoustic engineering and digital signal processing, and particularly relates to a fractional delay FIR (Finite Impulse Response) phase calibration method and system of a multichannel sonar system. Comprising the steps of signal acquisition and reference channel selection; high-precision relative delay estimation; calculating a cross-correlation function of other channel signals and the reference channel signal, performing coarse estimation by searching a peak point of the amplitude of the cross-correlation function, and performing fine estimation on the peak position by using a parabola interpolation method to obtain the delay time of each channel relative to the reference channel; designing an FIR fractional delay filter; digital filtering and phase calibration; verifying a calibration effect; and calculating the phase of each channel signal at the target frequency point after calibration, and counting the standard deviation of each channel signal so as to evaluate the improvement degree of phase consistency. The method aims at overcoming the defect that traditional integral multiple sampling delay correction precision is insufficient, high-precision phase compensation of a sub-sampling point level is achieved, and therefore the performance of algorithms such as beam forming of a multi-channel sonar system is remarkably improved.

A system for generating live sonar images is provided having a first and second sonar transducer assembly. The sonar transducer assemblies each have sonar transducer elements configured to transmit sonar beam(s) into an underwater environment to form respective coverage volumes. The sonar transducer assemblies each define a respective facing direction. The system includes bracket(s) having alignment feature(s). The bracket(s) are configured to mount the sonar transducer assemblies to a watercraft, and the alignment feature(s) are configured to position the sonar transducer assemblies so that the facing directions are different and relative to each other so as to create continuous coverage of the underwater environment. Continuous coverage has an overall coverage volume that is greater than either of the coverage volumes individually. Sonar return data from the sonar transducer elements is used to form a live sonar image representative of sonar returns received from the overall coverage volume.

Disclosed in the present invention is a method for identifying morphological features of an underwater pile group of a bridge on the basis of a three-dimensional sonar point cloud, comprising the following steps: collecting point cloud data of the three-dimensional morphology of underwater pile foundations of a bridge: using a three-dimensional real-time sonar system-mounted survey vessel to perform multi-directional scanning around the underwater pile foundations of the bridge and performing real-time stitching, so as to acquire point cloud data of the complete morphology of the underwater pile foundations; on the basis of the point cloud data of the complete morphology of the underwater pile foundations, performing pile foundation extraction by means of a point cloud minimum cut method, and on the basis of a single pile foundation extracted after segmentation, projecting the pile foundation point cloud to an XOY plane to obtain a planar pile foundation point cloud; on the basis of the planar pile foundation point cloud, performing pile foundation morphological feature identification by means of an iterative MAD method; and on the basis of the identification result, mapping a complete pile foundation morphological feature point cloud back to an original three-dimensional space on the basis of elevation information so as to obtain a three-dimensional pile foundation point cloud having complete morphological features. The present invention can implement accurate identification of complete pile foundation point cloud morphological features.

The invention discloses a high-frequency shallow water bottom reverberation signal modeling method, and belongs to the technical field of underwater acoustic engineering and signal processing. The method comprises the following steps: setting a modeling hypothesis; a cylindrical array geometric structure is constructed, scattering units are divided, and channel parameters and scattering functions are obtained in combination with a Bellhop tool and a GABIM model; generating a reverberation signal time domain expression, deducing an array receiving signal spatial domain expression and calculating a spatial spectrum; the model can also adjust underwater environment parameters to realize simulation under different conditions, and performs time domain and space domain theoretical analysis on reverberation signals based on a cylindrical array. Multi-dimensional underwater environment parameters are fused, and the modeling precision is improved; a receiving and transmitting combined cylindrical array is adapted, and spatial gain is embodied; experiments prove that the average error is within 3dB, the practicability is outstanding, support can be provided for design and optimization of the sonar system, and the method is suitable for underwater reverberation signal simulation and characteristic analysis of the sonar system in the high-frequency shallow water environment.

The invention discloses a dynamic reconfigurable towed linear array sonar system and an optimization method. The system comprises a water surface mother ship, a towed cable towed by the mother ship, and a towed platform connected to the tail end of the towed cable. A sonar array storage bin and a control system are arranged in the dragging platform; a cable track is fixedly arranged on the outer surface of the dragging cable; the device further comprises a plurality of sonar sliding blocks, and the sonar sliding blocks are meshed with the cable track through sliding grooves in the sonar sliding blocks so that the sonar sliding blocks can slide along the cable track. A sonar unit is installed on the sonar sliding block. A front driving mechanism and a rear driving mechanism are arranged at the head end and the tail end of the sonar sliding block correspondingly and used for driving the sonar sliding block to ascend or descend along the cable track. According to the invention, the attitude of the towing cable is changed by actively controlling the relative spatial position of the towing platform and the mother ship, and the sonar array attached to the cable is remodeled accordingly. Finally, by monitoring acoustic performance feedback, a'perception-decision-control-optimization 'closed-loop system is formed.

The invention provides a method and a system for positioning an underwater target with known depth. The method comprises the following steps: adopting a cross array as a receiving array; the two hydrophones in the horizontal direction form a first group of hydrophones, and the two hydrophones in the vertical direction form a second group of hydrophones; receiving a pulse signal of a target sound source, and estimating a time difference of arrival through a secondary cross-correlation method; estimating the pitch angle of the target sound source according to the time difference of arrival of the second group of hydrophones; estimating the azimuth angle of the target sound source according to the pitch angle of the target sound source and the time difference of arrival of the first group of hydrophones; and estimating the target sound source distance according to the target sound source depth and the pitch angle. The method has the advantages that under the condition that only the depth of the target position is known and the sound source and the receiving array cannot communicate, the target sound source can be accurately and rapidly subjected to direction finding and positioning. The method can be widely applied to an underwater passive sonar system with a known target depth, and can be expanded to a weak signal detection system.

The present invention relates to the field of waterway monitoring technology, and specifically, to a real-time monitoring method and system for water depth of a port waterway. It includes: S1, selecting a monitoring point in the waterway, installing an intelligent buoy for monitoring waterway data at the monitoring point, the intelligent buoy is used to monitor waterway data, and deploying an acoustic Doppler current profiler to monitor the bottom flow velocity; S2, collecting waterway data collected by a sonar system and an acoustic Doppler current profiler; S3, constructing a waterway sedimentation model, and combining the real-time waterway data after preprocessing, introducing a time-dependent function, and correcting the measurement error of the real-time water depth data caused by silt silting; S4, based on the above steps S1-S3, constructing a network including multiple monitoring points to form a three-dimensional monitoring system for the waterway. By establishing a preliminary waterway sedimentation model of sedimentation rate and average bottom flow velocity, and introducing a time-dependent function and terrain factors, the prediction accuracy of future water depth changes in the waterway is improved.

Sonar steering systems offering improved functionality and ease of use for an operator (e.g., an angler) are provided. A sonar steering system is configured to automatically adjust the directional coverage volume of the sonar system in a hands-free manner to allow the operator to focus on other tasks. Some such sonar steering systems are configured to adjust the directional coverage volume of the sonar transducers to maintain a target such as an area of interest (AOI) within the sonar display despite movement of the watercraft relative to the target. Accordingly, the coverage volume may be automatically adjusted to maintain the aim of the sonar transducers at a target that is moving through the water, such as a school of fish.

The invention relates to the technical field of underwater acoustic signal processing in a sonar system, in particular to a large-aperture array robust adaptive waveform recovery method based on focusing covariance sparse reconstruction, and the method comprises the steps: carrying out the time-frequency transformation of all array element receiving time domain data, and obtaining array element domain-frequency domain data; constructing sampling covariance matrixes corresponding to different frequency points according to the array element domain-frequency domain data; constructing a multi-frequency-point focusing covariance matrix according to the sampling covariance matrix and the array manifold vector corresponding to each frequency point; constructing a sparse dictionary matrix adaptive to the focusing covariance matrix according to the linear relation between the focusing covariances of the frequency points, and obtaining a sparse expression of the focusing covariance matrix; according to the sparse representation form of the focusing covariance matrix, utilizing a sparse criterion to carry out iterative reconstruction on the focusing covariance matrix; and robust adaptive waveform recovery is carried out by using the focusing covariance matrix after sparse iteration reconstruction. According to the method, the short-time adaptive waveform recovery performance of the large-aperture array is remarkably improved.

The invention relates to the technical field of underwater operation equipment, solves the problems that existing dam underwater crack repairing depends on divers or complex equipment, the automation degree is low, the construction period is long, the comprehensive cost is high and the adaptability is poor, and particularly relates to concrete dam underwater crack repairing and leaking stoppage equipment which comprises a robot for underwater cruise, and the robot comprises a machine body; the cruise vision module comprises a foresight navigation lens group, a look-around lens group, a bottom wide-angle lens, an active illumination system, an obstacle avoidance sonar system and a topographic mapping sonar; the crack detection module comprises a crack scanning ultrasonic detector, a high-resolution strip-shaped scanning lens group, a laser ray scanner, a multispectral imager, a laser distance measuring sensor, a water flow sensor and an attitude sensor, the crack repairing module comprises two groups of mechanical arms for punching and grouting, and the central controller controls the robot to execute. Crack filling, structure bonding recovery and long-acting sealing are achieved, and meanwhile the construction difficulty and the comprehensive cost are reduced.

The invention discloses a control chip of an underwater sonar system and underwater sonar equipment, the sonar system comprises a plurality of receiving array elements, the control chip comprises a processor system core and a programmable logic core, and the processor system core is used for controlling the programmable logic core to operate; the programmable logic core comprises a plurality of intellectual property cores, and each intellectual property core comprises a digital down-conversion module, an FFT (Fast Fourier Transform) module and a beam forming module; wherein the digital down-conversion module is used for obtaining a first frequency conversion signal based on an echo signal received by a receiving array element in response to a first instruction; the FFT module is used for responding to a second instruction and obtaining sub-band data based on the first frequency conversion signal; the beam forming module is used for responding to a third instruction and obtaining total output in a preset direction based on the sub-band data; and the detection module is used for obtaining target object information based on the total output in the preset direction.

The invention relates to the technical field of surface water body treatment, and discloses a multifunctional unmanned ship, which comprises a ship body, a power system, a control system, a sensor module, an execution module and a data communication module, the ship body adopts a streamline design, the load capacity is 55kg, and the anti-storm grade reaches above level 3; the power system is driven by hybrid energy and comprises a solar cell panel and a lithium battery pack. The control system supports autonomous navigation, path planning and obstacle avoidance functions based on an artificial intelligence algorithm; the sensor module comprises a water quality sensor probe, a visual identification system and a sonar system; the execution module comprises a garbage collection device and a rescue device; the data communication module comprises a wireless communication antenna, supports wireless network transmission and uploads collected data to a cloud platform. Water quality monitoring, water surface cleaning, fish and bird recognition, underwater topographic mapping and emergency rescue functions are integrated on a single platform, so that the comprehensive efficiency of water area management is remarkably improved.

The invention discloses a one-dimensional error analysis method, system and device for a synthetic aperture sonar imaging method, and relates to the technical field of image processing, and the one-dimensional error analysis method comprises the steps: calculating a joint directivity function of a transmitting array element and a receiving array element according to the directivity functions of the transmitting array element and the receiving array element, and determining the beam width of a sonar system; according to the farthest imaging distance and the beam width of the sonar system, calculating the coordinates of the target to be set in the azimuth direction in the imaging area; according to the geometrical relationship, calculating the distance error between the accurate instantaneous two-way slant distance between different positions in the sonar azimuth direction and the target and the approximate slant distance of the to-be-evaluated imaging method; determining the minimum number of targets to be set and coordinates in the distance direction in the imaging area, and determining a receiving array element of a distance error to be inspected; and calculating the distance error between the accurate instantaneous two-way slant distance and the approximate slant distance of the to-be-evaluated imaging method, so that the method can quickly evaluate the advantages and disadvantages of the sonar imaging method.

The present invention provides a method and system for underwater target detection based on microwave surface vibration sensing, comprising the following steps: Step S1: Using a carrier platform to drive a microwave transceiver to sense surface vibrations and extract surface vibration information generated by underwater target acoustic excitation; Step S2: Eliminating wave motion information and carrier platform motion information; Step S3: Analyzing the surface vibration information generated by underwater target acoustic excitation to locate the target water area; and Step S4: Detecting and locating the target and calculating its depth. The present invention proposes a method and system for underwater target detection based on microwave surface vibration sensing. The method utilizes a carrier platform equipped with a microwave transceiver to identify and locate underwater targets by extracting surface vibration information. This method addresses the difficulties encountered by existing underwater target detection methods in achieving maneuverable detection, long-distance detection, and accurate target positioning. It also overcomes the high power and bulk of existing active sonar systems and the heavy reliance of passive sonar on advanced materials and processes.

The invention provides a monitoring device for quickly checking river channel pollution discharge, and relates to the field of monitoring devices. The monitoring device comprises a remote control hovercraft platform, the remote control hovercraft platform comprises a hovercraft design, a power system, a control system and a communication system, the hovercraft design selects a hovercraft suitable for river width and water flow conditions, the power system uses an efficient lithium battery pack to ensure long-time endurance, and the communication system is connected with the control system. The control system comprises a GPS module, an automatic driving system and an obstacle avoidance system, the GPS module is used for real-time positioning and path planning, the obstacle avoidance system adopts a laser radar sensor and is used for detecting front obstacles and automatically avoiding the obstacles, and the communication system utilizes a radio communication technology. Through the high-definition camera and the infrared camera above the water surface and the camera and the sonar system underwater, omnibearing monitoring of the river channel environment is achieved, the system adopts a modular design, all the components are mutually independent, and expansion and maintenance are easy.

The invention provides a communication and positioning integrated sonar system, and relates to the technical field of communication, and the system comprises a communication module which is used for determining a communication algorithm according to an obtained communication distance and the signal-to-noise ratio of an original communication signal, carrying out the modulation and coding of the original communication signal through the communication algorithm, and transmitting the modulated and coded original communication signal to a communication module. Generating a communication code stream; the communication and positioning integrated module is used for embedding a preset original positioning signal into the communication code stream to generate a fusion signal through a coding multiplexing technology; and the positioning module is used for determining a positioning algorithm according to the signal-to-noise ratio and the coherent interference coefficient of the fused signal, and generating corresponding position information through the positioning algorithm according to the positioning information in the fused signal. According to the invention, the information transmission efficiency of the sonar system can be effectively improved.

The invention relates to the field of wharf construction, and particularly discloses a wharf bottom pile detection method based on multi-beam scanning and a BIM technology, and the method comprises the following steps: S1, installing and debugging data collection equipment which comprises an underwater three-dimensional sonar multi-beam measurement system and an unmanned ship matched with a high-precision inertial navigation system; s2, acquiring three-dimensional point cloud data of the underwater structure of the wharf by using a multi-beam sonar system, and performing data correction; s3, splicing, noise reduction and three-dimensional output processing are conducted on the collected wharf pile foundation data; s4, establishing a Revit model of the underwater pile foundation based on a building information model (BIM) technology; and S5, pile collision checking calculation is conducted on the basis of the Revit model of the underwater pile foundation, and the position of the pile foundation is adjusted and optimized till pile collision detection can be passed. The method has the advantages of being accurate in evaluation and high in checking calculation efficiency.

The invention relates to an underwater acoustic transducer which can resist long-term work under the condition of deep sea high water pressure, is high in sensitivity, wide in band, low in noise and high in electromagnetic interference resistance, is used in deep sea detection and communication sonar systems, and solves the problems that an existing underwater acoustic transducer is low in receiving sensitivity along with increase of water pressure, poor in long-term work corrosion resistance and low in cost. And noise of the hydrophone and external electromagnetic interference cause signal interference. A novel high polymer material is adopted to reduce acoustic impedance, enhance the coupling effect with seawater and reduce sound wave reflection loss. Meanwhile, by optimizing the internal structure design, the stability and durability of the device under the deep sea high pressure condition are ensured. And the hydrophone shell is made of an alloy material with good corrosion resistance, so that the hydrophone shell is prevented from being corroded in a marine environment for a long time, and the service life is prolonged. By improving the design and manufacturing process of the transducer, the transducer can cover acoustic signals in a broadband range, and the multi-spectrum requirement of a deep sea detection and communication system is met. Advanced noise suppression technology and shielding measures are adopted, noise of the hydrophone is effectively reduced, external electromagnetic interference resistance is improved, and it is guaranteed that high-quality acoustic data are obtained in a complex deep sea environment. In conclusion, the invention provides the hydrophone which is excellent in working performance in the deep sea high-pressure environment, has the characteristics of high sensitivity, broadband response and the like, can effectively resist the influence of a severe environment, and provides key technical support for deep sea detection and a communication sonar system.

The invention discloses a target positioning method and device based on a sonar system, and a storage medium, and the method comprises the steps: responding to a target point marked by a user on an azimuth history graph, determining a preset angle closest to an input side angle of a detection target corresponding to the target point, and taking the preset angle as an estimated side angle; and determining a left adjacent side angle and a right adjacent side angle which are adjacent to the estimated side angle on the left side and the right side. And determining an error correction direction and a correction coefficient of the estimated broadside angle according to the signal intensity corresponding to the estimated broadside angle, the signal intensity corresponding to the left adjacent broadside angle and the signal intensity corresponding to the right adjacent broadside angle. And correcting the estimated broadside angle according to the correction coefficient and the azimuth resolution corresponding to the estimated broadside angle. According to the method, the broadside angle corresponding to the user recording moment is not directly used as the actual broadside angle, but the orientation with the strongest actual signal of the received detection target is predicted, the actual broadside angle is determined, broadside angle errors caused by orientation resolution limitation are reduced, and the detection target can be positioned more accurately according to the actual broadside angle.

The present invention discloses a method and system for assessing fishery resources in the entire water layer using fishery acoustic methods. This method uses a multi-band sonar system to pre-detect each water layer of the target water body, obtain sonar echo data, analyze the sonar detection quality, and determine the optimal sonar frequency range. Water quality characteristics are detected based on this frequency, and receiving parameters are optimized to obtain fishery resource detection data and optimize data accuracy. Based on a deep learning algorithm, a fishery resource analysis model is constructed to assess the status of fishery resources in the target water body. The assessment results are integrated to generate a spatial distribution change map of fishery resources and predict resource change trends. The system includes modules such as sonar detection, data optimization, analysis and evaluation, and resource prediction, and can accurately assess and predict fishery resources in the entire water layer, improving the scientific nature and sustainability of fishery resource management.

The invention relates to the technical field of unmanned ship intelligent cruise, in particular to an unmanned ship intelligent cruise method and system based on multi-modal perception, and the method comprises the steps: determining a current navigation direction according to a current unmanned ship coordinate and a target task coordinate, carrying out the edge recognition of a remote sensing satellite image, and obtaining an obstacle contour image; performing contour boundary smoothing processing on the obstacle contour image to obtain an obstacle boundary image, performing path feasibility planning according to the obstacle boundary image, a radar system and a sonar system to obtain a coordinate navigation data set, and performing optimal path selection based on the coordinate navigation data set to obtain an optimal navigation path. According to the invention, the globality and efficiency of path planning of the unmanned ship can be improved, and fuel consumption and navigation time in the cruising process of the unmanned ship are reduced.

The acousto-optic combined underwater target autonomous searching and positioning method comprises the following steps: establishing an underwater target searching platform based on an underwater unmanned vehicle; pre-establishing an underwater target detection model on the underwater target searching platform; inputting a given target type, a task area and a target quantity into a task decision system; the task decision-making system firstly identifies information transmitted from the sonar system; the task decision system identifies information transmitted from the optical camera system; the task decision-making system judges the suspicious target object; the underwater unmanned vehicle continues to search or return voyage on the given target type, task area and target number, or acousto-optic combination is carried out in a return voyage target detection mode, and sonar detection and optical detection are combined far and near, and large-range preliminary screening and approaching recognition confirmation are combined; the underwater target searching efficiency is improved, the detection and discovery capability is also improved, and the problems of low searching efficiency, difficult positioning and the like are solved.

The invention provides an underwater environment area dynamic search method, which comprises the following steps of: transmitting and receiving a sound wave signal by using a multi-beam sonar system, obtaining a high-resolution underwater environment image, and extracting particle size distribution data of submarine sediments through image analysis; establishing a mapping model by combining the sound wave frequency and the sediment acoustic characteristics to calculate a scattering intensity distribution map; adopting a pattern recognition algorithm to recognize the sediment particle size and the sound wave incident angle, and correcting inertial navigation data errors; a spatial filtering parameter optimization model is established based on sediment particle size distribution, filtering parameters are adjusted to remove noise, and scattering signal features are extracted; the configuration of the receiving array and the search area are dynamically adjusted according to the particle size change of the sediment, accurate and real-time analysis and environment adaptability search of the particle size distribution of the underwater sediment are realized, and the efficiency and accuracy of underwater detection are greatly improved.

The present invention relates to the field of underwater acoustic information processing technology, and provides a method for normalizing active sonar imaging data, comprising: S1, constructing an azimuth-distance matrix: obtaining azimuth-distance data through a sonar system and storing it in a polar coordinate system; S2, smoothing the data: after constructing the azimuth-distance matrix, smoothing each row of data to reduce the impact of noise; S3, calculating expected echo intensity: after completing the smoothing process, calculating the expected echo intensity of each detection point using a data-driven method; normalizing each row of data according to the corresponding expected echo intensity; S4, coordinate system conversion: after the normalization process, converting the processed azimuth-distance matrix data from a polar coordinate system to a rectangular coordinate system. The present invention can reduce the interference of background reverberation and noise on the detection of small targets at long distances.

The application discloses an underwater crack sonar image simulation method, a storage medium and equipment, crack regions of a binary graph in optical crack data are migrated to a target model of a sonar system for observation, crack sonar images under different simulation parameters are obtained based on a sonar ray tracing principle, and a typical acoustic atlas is provided for detection of underwater cracks by using a sonar device, so that the problem that various forms of underwater cracks lack typical expressions in sonar images in the field of detection of underwater structure cracks by using a sonar technology at present is solved, and a basis is provided for subsequent related work of accurate identification of underwater structure cracks through sonar images.

The invention relates to the technical field of ship water area depth detection, and discloses a ship water area depth detection method and system, which captures an echo signal by introducing an energy threshold, and further judges the time multiple relationship and the specific energy relationship between potential main echoes and potential secondary echoes to determine the water area depth of a ship. The problem of depth misjudgment caused by weak real underwater echo signals of a traditional sonar system in a complex water area environment is effectively solved. Compared with the traditional identification logic which only depends on'the first arrival and the strongest energy ', the method provided by the invention can more accurately identify the real bottom echo, even if the energy is very weak, thereby avoiding the situation that the secondary echo is misjudged as the real water bottom echo, remarkably improving the accuracy and reliability of water depth detection, and improving the accuracy and reliability of water depth detection. Especially in challenging environments such as organism attached to a ship body or soft sludge at the water bottom, more reliable depth information guarantee is provided for ship navigation.

The present application provides a method and system for positioning an underwater target with a known depth. The method includes: using a cross array as a receiving array; two hydrophones in the horizontal direction form the first group of hydrophones, and two hydrophones in the vertical direction form the second group of hydrophones; receiving the pulse signal of the target sound source, and estimating the time difference of arrival by the method of quadratic cross-correlation; estimating the elevation angle of the target sound source according to the time difference of arrival of the second group of hydrophones; estimating the azimuth angle of the target sound source according to the elevation angle of the target sound source and the time difference of arrival of the first group of hydrophones; estimating the distance of the target sound source according to the depth and elevation angle of the target sound source. The advantages of the present application are as follows: in the case where only the depth of the target position is known and there is no communication between the sound source and the receiving array, the present application can accurately and quickly direction-find and position the target sound source. The present application can be widely applied to underwater passive sonar systems with known target depths and can be extended to weak signal detection systems.

The present application relates to a kind of sonar system compensation circuit and method based on multi-channel switching;Wherein the circuit uses cascade architecture, the core is to use domestic CBMG708 multiplexer to build at least one program-controlled gain stage, by the gain resistance of different resistance in series after each selection end is connected to operational amplifier, multiple signal channels with 6dB gradient basic gain are formed.Combined with FPGA+ARM dual-core control module, according to target action distance, corresponding channel is gated in real time, the fast and accurate gain compensation of sonar signal of different distances such as near, middle and far is realized.The method ensures that the output signal amplitude in the whole distance range is higher than the detection threshold, while having the advantages of small gain error, low power consumption and supply chain controllable, effectively solves the problem of insufficient flexibility and slow response of traditional single-channel compensation circuit.