Towed array shape measuring system

Abstract

The invention discloses a towed array shape measuring system which comprises a seabed positioning sound reference, a shipborne calibration communication unit and a towed attitude processing unit. The seabed positioning sound benchmark synchronously and periodically emits positioning sound pulse signals outwards to provide a position reference benchmark for the towed array; the shipborne calibration communication unit is used for performing absolute coordinate calibration and communication control and acquiring sound velocity profile information on a propagation path of the positioning sound pulse signal; and the towed attitude processing unit solves the real-time spatial position of each array element, and further reconstructs the dynamic formation of the whole towed array. According to the invention, through the long-baseline acoustic positioning network which is arranged at the seabed and has known accurate coordinates, time delay resolving is carried out on acoustic pulse signals received by array elements of the towed array, the problems of accumulative errors and response lag of calculation of a traditional dynamic model are avoided, and under the large maneuvering states of speed change, turning and the like of the tugboat, the time delay of the tugboat is solved. And the real spatial form of the towed array can be accurately obtained in real time.

Description

Technical Field

[0001] This invention belongs to the field of underwater acoustic engineering technology, and in particular relates to a towed array measurement system. Background Technology

[0002] Towed linear array sonar is a key device in underwater target detection. It detects and locates distant underwater targets by towing a linear array of multiple hydrophone elements underwater, utilizing the propagation characteristics of sound waves. However, towed arrays operate in complex marine environments, affected by current disturbances, tugboat maneuvers (such as acceleration, deceleration, and turning), and the array's own dynamic characteristics. This often causes deformations such as bending and twisting, making it impossible to maintain an ideal straight line or preset geometric configuration. Such array distortion directly leads to beamforming deviations and increased target azimuth estimation errors, severely impacting the sonar system's detection performance and positioning accuracy. Therefore, accurately and in real-time acquiring the actual spatial shape of the towed array (i.e., its "array configuration") is crucial for array compensation, beam optimization, and improved detection efficiency in sonar signal processing.

[0003] Currently, towed array measurement technology mainly includes the following two types:

[0004] 1. The method based on inertial sensors and dynamic models typically involves installing an inertial measurement unit (IMU) at the bow of a surface vessel or towed array. By combining parameters such as tow cable tension, vessel speed, and ocean currents, a cable-array coupled dynamic model is established to deduce the spatial position of the entire array. This method is applicable under steady-state towing conditions, but when the tugboat maneuvers significantly or the array is impacted by dynamic ocean currents, the model error accumulates significantly, making it difficult to accurately reflect the instantaneous shape of the array, especially at the tail of the array where the error is greater.

[0005] 2. Embedding depth and attitude sensors in the linear array for local attitude estimation involves deploying several attitude sensors (such as compasses and inclinometers) and depth sensors in the towed array, and reconstructing the array shape through piecewise fitting. While this method improves local accuracy, the number of sensors is limited, and it cannot obtain the absolute position information of the array elements. It still relies on model assumptions and has insufficient response to nonlinear deformations. Furthermore, existing systems generally suffer from low data update rates, large communication delays, and inability to adapt to large-scale maneuver measurements.

[0006] However, existing underwater acoustic positioning systems are mostly used for locating static or low-speed targets. A complete system solution suitable for continuous and high-precision array measurement of towed arrays under high-speed and maneuvering conditions has not yet been formed. Especially in deep sea and large-scale test areas, there are still technical bottlenecks in the deployment, calibration, synchronization, and real-time data processing of the system.

[0007] Therefore, there is an urgent need for a towed array formation measurement system that can adapt to the deep-sea environment, support large-scale maneuvering and towing, and has high-precision synchronization and real-time processing capabilities, in order to overcome the problems of insufficient formation measurement accuracy, slow response, and limited applicability in existing technologies. Summary of the Invention

[0008] To address the problem that existing towed array formation measurement technologies struggle to acquire the true formation in real time and with high precision under conditions of large-scale tugboat maneuvers and dynamic array deformation, this invention provides a towed array formation measurement system that is highly applicable, efficient, reliable, low-cost, and accurate in real time.

[0009] The technical solution of this invention is as follows:

[0010] A towed array measurement system includes a seabed positioning acoustic reference, a shipborne calibration and communication unit, and a towed attitude processing unit.

[0011] The seabed positioning acoustic reference is used to be deployed on the seabed to form an underwater long-baseline acoustic positioning network with known geodetic coordinates, and to periodically transmit positioning acoustic pulse signals outward in a synchronous manner to provide a position reference reference for the towed array.

[0012] The shipborne calibration and communication unit is used to perform time synchronization before the seabed positioning acoustic reference is deployed, and to perform absolute coordinate calibration and communication control during and after deployment, and to obtain sound velocity profile information on the propagation path of the positioning acoustic pulse signal.

[0013] The towed attitude processing unit is used to receive and process the positioning acoustic pulse signals collected by the acoustic receivers deployed on each element of the towed array, and combine the sound velocity profile information with the coordinates of the seabed positioning acoustic reference to calculate the real-time spatial position of each element based on the long baseline underwater acoustic positioning principle, thereby reconstructing the dynamic array of the entire towed array.

[0014] Preferably, the seabed positioning acoustic reference unit includes one synchronizer and six sets of acoustic references;

[0015] The synchronizer is used to synchronize the time of each device before the reference is deployed. The acoustic reference is deployed on the seabed. The deployment configuration of the 6 acoustic references makes the coverage of the underwater long baseline acoustic positioning network not less than 10km×10km.

[0016] Preferably, each acoustic reference includes a positioning acoustic transceiver, an acoustic calibration release device, and an anchoring structure;

[0017] The positioning acoustic transceiver is a cylindrical body with a diameter not exceeding 200mm, a height not exceeding 1.3m, and a weight not exceeding 40kg; its transducer is a transceiver-transducer; it has load-bearing structures at both ends and is connected to the float in the anchoring structure and the acoustic calibration release device via cables;

[0018] The acoustic calibration release device is a cylindrical body with a diameter of no more than 200mm, a height of no more than 1.3m, and a weight of no more than 40kg; its transducer is a transceiver transducer; one end has a load-bearing structure and is connected to the positioning acoustic transceiver device, and the other end is equipped with a load release mechanism that can release a weight of no less than 1200kg.

[0019] The anchoring structure includes a buoy, rope, sinker, and connectors. Before the sinker is released, the acoustic reference is in a state of negative buoyancy, and after the sinker is released, it becomes a state of positive buoyancy.

[0020] Preferably, the positioning sound transceiver is configured to: perform self-test, receive underwater acoustic commands from the shipborne calibration communication unit, and control the transmission and cessation of positioning sound pulses;

[0021] The positioning acoustic transceiver is powered by an internal battery and can support at least 100 hours of acoustic pulse transmission.

[0022] Preferably, the positioning sound transceiver transmits positioning sound pulses in a synchronous transmission mode, with a transmission period of no more than 4 seconds and a signal frequency of no more than 6kHz.

[0023] Preferably, the acoustic calibration release is configured to: perform a self-test, receive underwater acoustic commands from the rangefinder, respond to the rangefinder's interrogation signals, perform interrogation-response mutual ranging with other releases, conduct acoustic communication with the rangefinder, and release a sinker;

[0024] The acoustic calibration release device is powered by an internal battery and can operate for no less than 10 days under typical conditions of completing one calibration and one release.

[0025] Preferably, the anchoring structure is configured such that, after the sinker is released, the time it takes to bring the acoustic reference from the seabed at a depth of 2500 meters to the surface does not exceed 30 minutes.

[0026] Preferably, the shipborne calibration communication unit includes a sound velocity profiler, an attitude sensor, a satellite positioning unit, a rangefinder, and a positioning control terminal;

[0027] The sound velocity profiler is used to obtain full-depth sound velocity distribution information from the sea surface to the seabed in the test sea area;

[0028] The attitude sensor, combined with the satellite positioning unit, is used to provide the rangefinder with real-time position and attitude reference in the geodetic coordinate system;

[0029] The rangefinder is used to calibrate the absolute coordinates of all acoustic references through an acoustic interrogation-response method;

[0030] The positioning instrument control terminal is used to send underwater acoustic commands to the positioning acoustic transceiver device to control the start and stop of its positioning acoustic pulse transmission.

[0031] Preferably, the sound velocity profiler is powered by an internal battery, operates at a depth of not less than 3,500 meters, and is lowered by a marine winch to measure the sound velocity profile.

[0032] Preferably, the transducers of the rangefinder and the positioning instrument control terminal are both transceiver transducers, which are rigidly connected to the ship via a moon pool or a side mounting rod.

[0033] The acoustic communication distance between the rangefinder and the acoustic calibration release device is not less than 7 kilometers, and the maximum working depth is not less than 10 meters.

[0034] The acoustic communication distance between the positioning instrument control terminal and the positioning acoustic transceiver is not less than 7 kilometers, and the maximum working depth is not less than 10 meters.

[0035] The beneficial effects of this invention are as follows:

[0036] 1. A towed array measurement system is proposed. Through a long-baseline acoustic positioning network with known precise coordinates deployed on the seabed, the system directly calculates the time delay of the acoustic pulse signals received by each element of the towed array. This avoids the accumulated errors and response lag problems of traditional dynamic model calculations. Under high-maneuver conditions such as tugboat speed changes and turns, it can accurately and in real-time acquire the true spatial shape of the towed array. The maximum working depth of the seabed acoustic reference is no less than 6000 meters, and a single deployment can achieve array measurement over a sea area of ​​no less than 10km × 10km. It possesses strong deep-sea operational capabilities and a wide effective working area, meeting the needs of modern underwater exploration and large-scale marine surveys for towed array measurement.

[0037] 2. Through an acoustic interrogation-response mechanism between the shipborne rangefinder and the acoustic reference, combined with ship position and attitude information, the absolute coordinate calibration of all seabed acoustic references can be efficiently completed. The acoustic reference adopts an anchored structure and integrates an acoustic release device. After the test, it can be released and retrieved by command, reducing operating costs and improving equipment reusability. The system can simultaneously receive and process positioning signals from no less than 1500 acoustic channels, with a high sampling frequency (no less than 12kHz). Combined with sound velocity profile correction and high-performance workstation calculation, it ensures real-time processing and display of large amounts of data. The system highly integrates deployment, calibration, measurement, control, and retrieval functional modules, with a clear operation process and strong practicality.

[0038] 3. The key equipment of the system (such as the positioning sound transceiver and acoustic calibration release device) adopts pressure-resistant and corrosion-resistant materials, internal battery power supply and transceiver combination transducer design, with compact structure, can work stably for no less than 10 days in harsh deep-sea environment, ensuring the reliability of long-term sea trials. Attached Figure Description

[0039] Figure 1 The present invention provides a schematic diagram of a towed array measurement system. Detailed Implementation

[0040] The present invention will be further described below with reference to specific embodiments and accompanying drawings:

[0041] Example 1:

[0042] like Figure 1 As shown, this embodiment provides a towed array formation measurement system, including a seabed positioning acoustic reference, a shipborne calibration communication unit, and a towed attitude processing unit.

[0043] The seabed positioning acoustic reference is used to be deployed on the seabed to form an underwater long-baseline acoustic positioning network with known geodetic coordinates, and to periodically transmit positioning acoustic pulse signals outward in a synchronous manner to provide a position reference reference for the towed array.

[0044] The shipborne calibration and communication unit is used to perform time synchronization before the seabed positioning acoustic reference is deployed, and to perform absolute coordinate calibration and communication control during and after deployment, and to obtain sound velocity profile information on the propagation path of the positioning acoustic pulse signal.

[0045] The towed attitude processing unit is used to receive and process the positioning acoustic pulse signals collected by the acoustic receivers deployed on each element of the towed array, and combine the sound velocity profile information with the coordinates of the seabed positioning acoustic reference to calculate the real-time spatial position of each element based on the long baseline underwater acoustic positioning principle, thereby reconstructing the dynamic array of the entire towed array.

[0046] In this invention, the overall workflow can be divided into three steps: first, the seabed positioning acoustic reference is deployed to the seabed and the absolute coordinate calibration is completed; second, the positioning acoustic signal emitted by the seabed positioning acoustic reference is received and collected; and third, the real-time position of each element of the towed array is calculated through data processing to reconstruct the dynamic array shape.

[0047] Therefore, the towed array formation measurement system provided in Embodiment 1 of the present invention comprises three main parts: a seabed positioning acoustic reference, a shipborne calibration and communication unit, and a towed attitude processing unit. The specific structure and function of each part are as follows:

[0048] I. Seabed Positioning Acoustic Reference Point: The seabed positioning acoustic reference point is the geodetic reference point of the system, used to construct an underwater long-baseline acoustic positioning network. It consists of one synchronizer and six sets of acoustic reference points.

[0049] 1. Synchronizer: Before the reference is deployed, it is used to synchronize the time of all equipment participating in the test (including shipboard equipment and acoustic reference) to ensure that the clock of the whole system is consistent.

[0050] 2. Acoustic reference: Each acoustic reference includes a positioning acoustic transceiver, an acoustic calibration release device, and an anchoring structure. A total of 6 sets are deployed, which can realize towed array array measurement in a sea area of ​​not less than 10km×10km. Its maximum working depth is not less than 6000 meters, and its continuous working time is not less than 10 days.

[0051] (1) Positioning sound transceiver:

[0052] Structure and Appearance: The overall structure is cylindrical, with a diameter not exceeding 200mm, a height not exceeding 1.3m, and a weight not exceeding 40kg. The hull is made of pressure-resistant and seawater corrosion-resistant materials (such as stainless steel). Load-bearing structures are designed at both ends for easy connection to mooring buoys and acoustic calibration release devices via cables.

[0053] Core components and power supply: The transducer uses a combined transceiver transducer. It is powered by an internal battery and can support at least 100 hours of acoustic pulse emission.

[0054] Functions and Signals: The main functions include self-testing, receiving underwater acoustic commands from the shipborne unit (positioning instrument control terminal), and transmitting and stopping positioning acoustic pulses. Positioning acoustic pulses are transmitted synchronously, with a transmission period not exceeding 4 seconds and a signal frequency not exceeding 6kHz.

[0055] (2) Acoustic calibration release device:

[0056] Structure and Appearance: The overall structure is cylindrical, with a diameter not exceeding 200mm, a height not exceeding 1.3m, and a weight not exceeding 40kg. The shell material is the same as that of the positioning acoustic transceiver. One end has a load-bearing structure connected to the positioning acoustic transceiver, and the other end is a load release mechanism.

[0057] Core components and power supply: The transducer adopts a combined transceiver transducer. It is powered by an internal battery and can operate for no less than 10 days under typical conditions of completing one calibration and one release.

[0058] Functions and performance: Main functions include self-testing, receiving underwater acoustic commands from the rangefinder, responding to interrogation signals from the rangefinder, conducting interrogation-response mutual ranging with other release devices, acoustic communication with the rangefinder, and releasing a sinker. Its release mechanism can release sinkers weighing no less than 1200 kg.

[0059] (3) Anchorage structure:

[0060] Composition: Includes buoys, ropes, sinkers, and connectors, all made of seawater-resistant materials.

[0061] Operating status: Before the slack is released, the entire acoustic reference system (including the device, release mechanism, and slack) is under negative buoyancy in seawater and sits stably on the bottom. After the slack is released, the acoustic reference system (device and release mechanism) becomes under positive buoyancy under the action of the buoy and can rise from the seabed. For example, the time to rise from the seabed at a depth of 2500 meters to the surface does not exceed 30 minutes.

[0062] II. Shipborne Calibration and Communication Unit: The shipborne calibration and communication unit is installed on the test vessel and is responsible for reference calibration, communication control, and environmental parameter measurement. It includes one of each of the following devices:

[0063] 1. Sound velocity profiler: Powered by an internal battery, with a working depth of not less than 3500 meters.

[0064] Usage: The ship is slowly lowered to the seabed using a ship winch. The sound speed at different water depths is measured in real time during the lowering and retrieval process to obtain full-depth sound speed profile information of the test sea area.

[0065] Function: To provide accurate sound velocity data for sound ray bending correction in subsequent positioning calculations.

[0066] 2. Attitude sensor and satellite positioning unit: Power supply is 220V AC.

[0067] The satellite positioning unit includes a satellite receiver and antenna, combined with an attitude sensor (such as an inertial measurement unit, IMU).

[0068] Function: To measure the position, heading, roll, pitch and other attitude information of the test ship in real time, and to fuse this information to provide the rangefinder with a high-precision position and attitude reference in a geodetic coordinate system.

[0069] 3. Rangefinder:

[0070] Installation and Connection: The transducer is a combined transceiver transducer. During use, it is rigidly connected to the hull via the ship's moon pool or side mounting rod, ensuring that the transducer is submerged in water at a depth of not less than 10 meters.

[0071] Power supply and performance: Powered by 220V AC. The acoustic communication distance between the device and the underwater acoustic calibration release unit is no less than 7 kilometers.

[0072] Core function: Send various underwater acoustic commands to the release device.

[0073] It transmits an interrogation signal and receives a response signal from the release device to perform one-way ranging.

[0074] Receive the mutual ranging data reported by each release device after the mutual ranging is completed.

[0075] By combining its precise geodetic coordinates, attitude, and sound velocity profile information, the absolute coordinates of all seabed acoustic references in the geodetic coordinate system are calculated, and the calibration work is completed.

[0076] 4. Positioning device control terminal:

[0077] Installation and Connection: The transducer is a combined transceiver transducer. The installation method is the same as that of the rangefinder. It is rigidly connected to the ship through the moon pool or the side mounting rod. The maximum working depth is not less than 10 meters.

[0078] Power supply and performance: Powered by 220V AC. The acoustic communication distance with the seabed positioning acoustic transceiver is no less than 7 kilometers.

[0079] Core function: Sends underwater acoustic commands to underwater positioning acoustic transceivers, specifically for controlling the "on" and "off" states of positioning acoustic pulse transmission.

[0080] III. Drag Attitude Processing Unit: The drag attitude processing unit is responsible for signal acquisition, data processing, and formation display.

[0081] 1. Towed array element acoustic receiver: Essentially a high-sensitivity hydrophone. Each element of the towed linear array is equipped with this acoustic receiver, which is used to receive the positioning acoustic pulse signal emitted by the seabed acoustic reference.

[0082] The acoustic receivers of all array elements transmit the collected analog signals to the signal acquisition system on the test vessel via a dedicated underwater adapter cable.

[0083] 2. High-performance workstation: Powered by 220V AC, it is the core of the system's data processing.

[0084] (1) Hardware interface: Equipped with a high-speed data acquisition card and an Ethernet port, it can receive positioning acoustic pulse waveform data from no less than 1500 acoustic channels of the towed array in real time via UDP or TCP protocol, and the signal waveform sampling frequency is no less than 12kHz.

[0085] (2) Software system: Dedicated data processing software is loaded and run on the workstation. This software mainly includes:

[0086] 1) Data Preprocessing Module: Receives and stores waveform data from all channels; performs preprocessing such as filtering and denoising on the received positioning acoustic pulses; calculates the acoustic wave propagation delay between each array element and each acoustic reference. The system design ensures that the number of positioning acoustic pulses involved in processing is no less than 80% of the total number of acoustic reference pulses emitted during the entire test, to guarantee data reliability.

[0087] 2) Positioning and calculation module: Based on the principle of long-baseline underwater acoustic positioning, it uses the pre-processed time delay data, known acoustic reference coordinates and sound velocity profile information, and corrects the measurement error caused by the sound velocity gradient through the sound ray bending compensation algorithm. Finally, it calculates the high-precision relative position of each towed array element and realizes array shape measurement.

[0088] 3) Display and control module: Displays the calculated towed array posture, position of each element, and other information in real time in a two-dimensional or three-dimensional graphical manner, and provides a human-computer interaction interface.

[0089] The present invention provides a towed array formation measurement system, the block diagram of which is shown below. Figure 1 As shown, the specific operating steps are as follows:

[0090] ① Status check: Before the test, each device (seabed positioning acoustic reference, shipborne calibration communication unit, towed attitude processing unit) is powered on for self-test and functional check to confirm that there are no faults.

[0091] ② Sound speed profile measurement: The test vessel sails to the test sea area, and a sound speed profiler is deployed to complete the measurement of sound speed information at all ocean depths in that sea area.

[0092] ③ Placement and preliminary calibration of the positioning acoustic reference:

[0093] a. The test vessel sails to the preset coordinate point and uses a synchronizer to complete the timing settings of all equipment.

[0094] b. Deploy the first set of acoustic reference lines to the seabed.

[0095] c. After deploying the second set of acoustic references, the test vessel orbits its coordinates along a preset trajectory (such as a circle). During this period, the shipborne rangefinder conducts multiple "interrogation-response" distance measurements with the acoustic calibration release device of the acoustic reference, and calculates the absolute coordinates of the acoustic reference (as initial known points) by combining sound ray correction technology, satellite positioning, and attitude sensor data.

[0096] ④ Full network calibration of acoustic reference coordinates:

[0097] a. After all six acoustic reference sets are deployed, the shipborne rangefinder sends a "mutual ranging" command to each reference.

[0098] b. After receiving the instruction, each benchmark calibration release device will conduct an "interrogation-response" process to complete the distance measurement between each other.

[0099] c. After receiving all mutual distance measurement data, the rangefinder combines the known initial point coordinates, sound speed information, and its own ship position to calculate the geodetic coordinates of all 6 sets of acoustic references, thus completing the calibration.

[0100] ⑤ Activate positioning pulse transmission:

[0101] a. Use the shipborne positioning instrument control terminal to send an "on" command to all seabed positioning acoustic transceivers.

[0102] b. Each device begins to synchronously emit positioning sound pulses at a preset cycle (e.g., 4 seconds).

[0103] ⑥ Towed navigation and formation measurement:

[0104] a. The test vessel released the tow array and began towing navigation tests within the sea area covered by the positioning network consisting of six acoustic references.

[0105] b. Each element receiver on the towed array continuously receives positioning sound pulses.

[0106] c. The received acoustic signals are collected and transmitted in real time to the high-performance workstation on the ship via Ethernet.

[0107] d. The data processing software on the workstation calculates in real time and outputs the dynamic formation of the dragged array.

[0108] ⑦ Stop pulse emission and repeat the test:

[0109] a. After a single test flight, a "stop" command is sent through the positioning instrument control terminal to stop the transmission of positioning acoustic pulses.

[0110] b. If multiple tests on different routes are required, repeat steps ⑤-⑥.

[0111] ⑧ Recycling:

[0112] a. Retrieve the towed array: After all sea trials are completed, retrieve the towed array to the test vessel.

[0113] b. Retrieval of Acoustic Reference Points: The test vessel sails to the vicinity of the sea surface where the acoustic reference points to be retrieved are located. A "release" command is transmitted to the calibration release device of the reference point via a rangefinder. Upon receiving the command, the release device activates and releases the sinker; the acoustic reference point (positioning acoustic transceiver and calibration release device) rises to the surface under the influence of a buoy and is retrieved; this process is repeated until all acoustic reference points are retrieved.

[0114] Through the above implementation methods, the towed array formation measurement system of the present invention realizes real-time, high-precision measurement of the spatial morphology of underwater towed arrays under complex maneuvering conditions.

[0115] It should be noted that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Equivalent modifications made based on the above embodiments are all within the scope of protection of the present invention.

Claims

1. A towed array measurement system, characterized in that, This includes an underwater positioning acoustic reference, a shipborne calibration and communication unit, and a towed attitude processing unit; The seabed positioning acoustic reference is used to be deployed on the seabed to form an underwater long-baseline acoustic positioning network with known geodetic coordinates, and to periodically transmit positioning acoustic pulse signals outward in a synchronous manner to provide a position reference reference for the towed array. The shipborne calibration and communication unit is used to perform time synchronization before the seabed positioning acoustic reference is deployed, and to perform absolute coordinate calibration and communication control during and after deployment, and to obtain sound velocity profile information on the propagation path of the positioning acoustic pulse signal. The towed attitude processing unit is used to receive and process the positioning acoustic pulse signals collected by the acoustic receivers deployed on each element of the towed array, and combine the sound velocity profile information with the coordinates of the seabed positioning acoustic reference to calculate the real-time spatial position of each element based on the long baseline underwater acoustic positioning principle, thereby reconstructing the dynamic array of the entire towed array.

2. The towed array formation measurement system according to claim 1, characterized in that, The seabed positioning acoustic reference unit includes one synchronizer and six sets of acoustic references; The synchronizer is used to synchronize the time of each device before the reference is deployed. The acoustic reference is deployed on the seabed. The deployment configuration of the 6 acoustic references makes the coverage of the underwater long baseline acoustic positioning network not less than 10km×10km.

3. The towed array formation measurement system according to claim 2, characterized in that, Each acoustic reference system includes a positioning acoustic transceiver, an acoustic calibration release device, and an anchoring structure. The positioning acoustic transceiver is a cylindrical body with a diameter not exceeding 200mm, a height not exceeding 1.3m, and a weight not exceeding 40kg; its transducer is a transceiver-transducer; it has load-bearing structures at both ends and is connected to the float in the anchoring structure and the acoustic calibration release device via cables; The acoustic calibration release device is a cylindrical body with a diameter of no more than 200mm, a height of no more than 1.3m, and a weight of no more than 40kg; its transducer is a transceiver transducer; one end has a load-bearing structure and is connected to the positioning acoustic transceiver device, and the other end is equipped with a load release mechanism that can release a weight of no less than 1200kg. The anchoring structure includes a buoy, rope, sinker, and connectors. Before the sinker is released, the acoustic reference is in a state of negative buoyancy, and after the sinker is released, it becomes a state of positive buoyancy.

4. The towed array formation measurement system according to claim 3, characterized in that, The positioning acoustic transceiver is configured to: perform self-test, receive underwater acoustic commands from the shipborne calibration communication unit, and control the transmission and cessation of positioning acoustic pulses; The positioning acoustic transceiver is powered by an internal battery and can support at least 100 hours of acoustic pulse transmission.

5. The towed array formation measurement system according to claim 4, characterized in that, The positioning sound transceiver device transmits positioning sound pulses in a synchronous transmission mode, with a transmission period of no more than 4 seconds and a signal frequency of no more than 6kHz.

6. The towed array formation measurement system according to claim 3, characterized in that, The acoustic calibration release is configured to: perform self-test, receive underwater acoustic commands from the rangefinder, respond to interrogation signals from the rangefinder, perform interrogation-response mutual ranging with other releases, conduct acoustic communication with the rangefinder, and release a sinker. The acoustic calibration release device is powered by an internal battery and can operate for no less than 10 days under typical conditions of completing one calibration and one release.

7. A towed array formation measurement system according to claim 3 or 6, characterized in that, The anchoring structure is configured such that, after the sinker is released, the time it takes to bring the acoustic reference from the seabed at a depth of 2,500 meters to the surface does not exceed 30 minutes.

8. The towed array formation measurement system according to claim 1, characterized in that, The shipborne calibration communication unit includes a sound velocity profiler, an attitude sensor, a satellite positioning unit, a rangefinder, and a positioning control terminal. The sound velocity profiler is used to obtain the full-depth sound velocity distribution information from the sea surface to the seabed in the test sea area; The attitude sensor, combined with the satellite positioning unit, is used to provide the rangefinder with real-time position and attitude reference in the geodetic coordinate system; The rangefinder is used to calibrate the absolute coordinates of all acoustic references through an acoustic interrogation-response method; The positioning instrument control terminal is used to send underwater acoustic commands to the positioning acoustic transceiver device to control the start and stop of its positioning acoustic pulse transmission.

9. A towed array formation measurement system according to claim 8, characterized in that, The sound velocity profiler is powered by an internal battery, operates at a depth of no less than 3,500 meters, and is lowered by a ship's winch to measure the sound velocity profile.

10. A towed array formation measurement system according to claim 8, characterized in that, The transducers of the rangefinder and the positioning instrument control terminal are both transceiver transducers, which are rigidly connected to the ship through the moon pool or the side mounting rod. The acoustic communication distance between the rangefinder and the acoustic calibration release device is not less than 7 kilometers, and the maximum working depth is not less than 10 meters. The acoustic communication distance between the positioning instrument control terminal and the positioning acoustic transceiver is not less than 7 kilometers, and the maximum working depth is not less than 10 meters.

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