Wide dynamic underwater sound collection method suitable for underwater glider and hydrophone

Abstract

The invention discloses a wide dynamic underwater sound acquisition method suitable for an underwater glider and a hydrophone, and the method comprises the steps: configuring a unique hydrophone into four parallel band-pass filtering and amplifying circuits, each band-pass filtering and amplifying circuit having different acquisition frequency bands; after the underwater glider enters water, underwater sound collection is carried out based on the only installed hydrophone, and underwater sound signals of four collection frequency bands are collected at the same time through four parallel band-pass filtering and amplifying circuits. Through four paths of differentiated gains and frequency segmentation, the wide dynamic full frequency band can be covered, the dynamic range is improved, a single hydrophone integrates four channels, cables and installation space among multiple devices are saved, and the underwater glider compact layout is adapted; the channels are activated on demand, the total power consumption can be reduced, and the endurance time is prolonged. Under the conditions of low power consumption and limited volume of the underwater glider, wide dynamic range signal acquisition can be realized, and signals can be processed in real time.

Description

Technical Field

[0001] This application relates to the field of deep-sea marine instrument technology, and in particular to a wide dynamic range underwater acoustic acquisition method and hydrophone suitable for underwater gliders. Background Technology

[0002] Underwater gliders, as a new type of unmanned underwater transport platform, have shown broad application prospects in fields such as marine environmental monitoring, resource exploration, and military reconnaissance due to their characteristics of low power consumption, long range, and wide-area operation. Underwater acoustic signals, as an important carrier of underwater information transmission, play a crucial role in the acquisition and analysis of these signals for tasks such as marine scientific research, underwater target detection, and communication.

[0003] However, underwater gliders are small underwater robot platforms with limited space for carrying sensors and limited energy, which can affect the quality of underwater acoustic acquisition in complex marine environments. Summary of the Invention

[0004] In view of this, this application provides a wide dynamic range underwater acoustic acquisition method and hydrophone suitable for underwater gliders. It integrates a 4-channel bandpass filter amplifier circuit into a single hydrophone housing (the size is smaller than that of traditional multi-hydrophone arrays), and uses a "gain gradation + frequency segmentation + dynamic switching" mechanism to achieve wide dynamic range coverage. It does not require the additional deployment of multiple hydrophones or gain switching circuits, which solves the strict limitations of underwater gliders on equipment size and power consumption, while meeting the requirements of "high and low frequency coverage and synchronous acquisition of strong and weak signals" in complex underwater acoustic environments.

[0005] According to one aspect of this application, a wide dynamic range underwater acoustic acquisition method suitable for underwater gliders is provided, the wide dynamic range underwater acoustic acquisition method suitable for underwater gliders includes: For the single hydrophone, the single hydrophone is configured as a 4-channel parallel bandpass filter amplifier circuit, and each channel of the bandpass filter amplifier circuit is configured to a different acquisition frequency band. The configured unique hydrophone is installed on the underwater glider so that underwater sound can be collected based on the installed unique hydrophone after the underwater glider is launched into the water. When the single hydrophone is collecting underwater acoustic signals, it simultaneously collects underwater acoustic signals from four frequency bands through a parallel four-channel bandpass filter amplifier circuit. The underwater glider is also equipped with a memory array, and the underwater acoustic signals collected from each frequency band are independently stored in the corresponding memory unit of the memory array.

[0006] According to another aspect of this application, a hydrophone is provided, the hydrophone corresponding to an underwater acoustic signal acquisition system, the underwater acoustic signal acquisition system comprising: Signal acquisition module, signal processing module, control module, and information interaction module; The signal acquisition module is used to acquire raw underwater acoustic signals and convert the acquired raw underwater acoustic signals into electrical signals; The signal processing module is used to filter, amplify, and digitize electrical signals to obtain digitized underwater acoustic signals. The control module is used to control the signal acquisition module and the signal processing module; The information interaction module is used to communicate with the main control system of the underwater glider.

[0007] Based on the above technical solution, this application provides a wide dynamic range underwater acoustic acquisition method and hydrophone suitable for underwater gliders. A single hydrophone is configured as a four-channel parallel bandpass filter amplifier circuit, with each channel representing a different acquisition frequency band. After the underwater glider is launched, underwater acoustic acquisition is performed based on the installed single hydrophone. The four parallel bandpass filter amplifier circuits simultaneously acquire underwater acoustic signals from four acquisition frequency bands. Through four channels of differentiated gain and frequency segmentation, a wide dynamic range can be covered, improving the dynamic range. A single hydrophone integrates four channels, eliminating the need for cables and installation space between multiple devices, and adapting to the compact layout of underwater gliders. Channels are activated on demand, reducing overall power consumption and extending endurance. This method enables wide dynamic range signal acquisition and real-time signal processing in the context of low power consumption and limited size of underwater gliders.

[0008] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0009] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A flowchart illustrating a wide dynamic range underwater acoustic acquisition method suitable for underwater gliders provided in an embodiment of this application is shown. Figure 2 This paper illustrates a schematic diagram of an underwater acoustic signal acquisition system architecture suitable for underwater gliders, provided in an embodiment of this application. Figure 3 This illustration shows a schematic diagram of different frequency bands of marine acoustic signals provided in an embodiment of this application; Figure 4 A schematic diagram of the structure of a hydrophone provided in an embodiment of this application is shown. Detailed Implementation

[0010] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0011] This embodiment provides a wide dynamic range underwater acoustic acquisition method suitable for underwater gliders, the method comprising: Step 101: For the single hydrophone, configure the single hydrophone as a 4-channel parallel bandpass filter amplifier circuit, and configure each channel of the bandpass filter amplifier circuit to a different acquisition frequency band.

[0012] Step 102: Install the configured unique hydrophone on the underwater glider so that underwater sound can be collected based on the installed unique hydrophone after the underwater glider is launched.

[0013] Step 103: When the only hydrophone is collecting underwater acoustic signals, it simultaneously collects underwater acoustic signals of four frequency bands through a parallel four-channel bandpass filter amplifier circuit. The underwater glider is also equipped with a memory array, and the underwater acoustic signals of each frequency band are independently stored in the corresponding memory unit of the memory array.

[0014] Most existing underwater acoustic signal acquisition systems use multi-channel hydrophone arrays (multiple hydrophones) to acquire multiple signals. However, underwater gliders are small underwater robot platforms with limited space for sensors and limited energy, making them highly sensitive to the size and power consumption of underwater acoustic signal acquisition systems. Underwater acoustic signals are easily saturated at low frequencies (such as low-frequency impacts caused by severe sea conditions or ship noise), while at high frequencies they may be covered by environmental noise, making it difficult to acquire signals completely and without distortion over a wide dynamic range. Most underwater acoustic signal systems rely on offline sampling and post-processing, resulting in large data volumes, high storage and communication costs, and power consumption that is difficult to meet the needs of small underwater gliders for long-term autonomous platforms.

[0015] In the above embodiments of this application, an underwater acoustic signal acquisition system can be built and installed on a single hydrophone so as to achieve small size, low power consumption, wide dynamic range, and real-time processing of underwater acoustic signals.

[0016] Specifically, the working process of an underwater acoustic signal acquisition system is as follows: Figure 1 As shown, the underwater acoustic signal acquisition system is as follows: Figure 2 As shown, the underwater acoustic signal acquisition system is installed on the hydrophone, which is in turn installed on the underwater glider. The underwater glider also carries a main control system and a battery pack. Specifically, the underwater acoustic signal acquisition system serves the hydrophone and includes a signal acquisition module, a signal processing module, a control module, and an information interaction module. In particular, it is... Figure 2As shown, the underwater acoustic signal acquisition system also includes a data storage module, i.e., a memory array, for storing the acquired underwater acoustic signals, and a power management module for providing power to the hydrophones. The underwater glider is equipped with a satellite communication antenna for communicating with the shore-based system via a communication satellite.

[0017] Furthermore, by synchronously acquiring underwater acoustic signals of different frequency bands through four parallel bandpass circuits, it is possible to capture underwater acoustic signals of the entire frequency band without omission, meeting the needs of multiple scenarios such as marine biological acoustics and communication signals; each independent gain level (such as 60dB / 40dB / 30dB / 20dB) matches the signal strength of different frequency bands, avoiding high and low frequency signal saturation or signal-to-noise ratio imbalance; the memory array stores frequency bands independently to prevent signal crosstalk and facilitate subsequent frequency division analysis and feature extraction; the unique hydrophone multiplexing design reduces the size and power consumption of the equipment and is suitable for the limited payload of underwater gliders.

[0018] Optionally, in step 101, the single hydrophone is configured as a 4-channel parallel bandpass filter amplifier circuit, including: Step 1011: Construct a bandpass filter amplifier circuit based on a high-pass equalizer, gain module, adjustable digital anti-aliasing filter, differential driver, and digital-to-analog converter.

[0019] Step 1012: In the single hydrophone, a 4-channel parallel bandpass filter amplifier circuit is integrated.

[0020] In the above embodiments of this application, such as Figure 1 As shown, the bandpass filter amplifier circuit consists of a high-pass equalizer, a gain module, an adjustable digital anti-aliasing filter, a differential driver, and a digital-to-analog converter. Simultaneously, four parallel bandpass filter amplifier circuits are integrated within a single hydrophone. The high-pass equalizer is controlled by a microcontroller unit and can be turned on or off. A clock, quartz crystal oscillator, and clock buffer are also added when integrating the four parallel bandpass filter amplifier circuits. The microcontroller unit also integrates serial peripheral interfaces—master-output-slave-in, master-in-slave-output, chip select, and clock. Figure 1In this system, the clock provides a unified time reference for the entire hydrophone, ensuring that all modules (such as the high-pass equalizer, adjustable digital anti-aliasing filter, and digital-to-analog converter) work in precise timing. For example, during analog-to-digital conversion, the clock signal controls the sampling time, ensuring the stability of the sampling frequency and thus accurately converting continuous analog underwater acoustic signals (electrical signals) into discrete digital underwater acoustic signals. The quartz crystal oscillator is a high-precision frequency source that utilizes the piezoelectric effect of quartz crystals to generate a stable and precise oscillation frequency. It provides the fundamental frequency signal for the clock circuit and is the source of the clock signal for the entire underwater acoustic signal acquisition system. The stability of its output frequency directly affects the accuracy of the clock signal, and consequently, the accuracy and reliability of the hydrophone's underwater acoustic signal processing. The clock buffer is used to buffer and amplify the clock signal generated by the quartz crystal oscillator, enhancing the driving capability of the clock signal. Since the clock signal needs to drive multiple modules, the clock buffer ensures that the clock signal maintains sufficient amplitude and a good waveform when transmitted to each module, avoiding abnormal module operation due to signal attenuation or distortion. The reference voltage provides a stable voltage reference for the analog circuits (such as amplifiers and filters) in a hydrophone. During signal amplification and filtering, the operating characteristics of many circuits (such as gain and cutoff frequency) are related to the reference voltage. A stable reference voltage ensures the stable performance of these circuits and reduces signal distortion and errors caused by voltage fluctuations. The Serial Peripheral Interface - Master-Output-Slave-Input is one of the data transmission lines of the serial peripheral interface, used by the master device (such as a microcontroller unit) to send data to slave devices (such as digital-to-analog converters). In the hydrophone's underwater acoustic signal acquisition system, the microcontroller unit transmits control commands, configuration parameters, and other information to various modules via the SPI-MOSI line, enabling the setting of module operating modes and parameter adjustments. The Serial Peripheral Interface - Chip Select is used to select a specific slave device for communication. When multiple slave devices are connected to the same SPI bus in the underwater acoustic signal acquisition system, the microcontroller unit activates the target slave device by controlling the SPI-CS signal, enabling it to transmit data with the master device, while other unselected slave devices remain inactive to avoid bus conflicts. The Serial Peripheral Interface - Clock provides a clock synchronization signal for data transmission through the SPI interface. It controls the data transmission rhythm on the SPI-MOSI (master-out, slave-in) and SPI-MISO (master-in, slave-out) lines, ensuring data transmission and reception synchronization between the master and slave devices, and guaranteeing the accuracy and reliability of data transmission.

[0021] Optionally, a single hydrophone is used to acquire the initial underwater acoustic signal. This single hydrophone corresponds to a shared gain module for four bandpass filter amplifier circuits. Each bandpass filter amplifier circuit is controlled by the same microcontroller unit, and each bandpass filter amplifier circuit is configured with a different gain level. The gain corresponding to any gain level is provided jointly by the shared gain module and the gain module built into the bandpass filter amplifier circuit. In step 103, underwater acoustic signals in four acquisition frequency bands are simultaneously acquired through the four parallel bandpass filter amplifier circuits, including: Step 1031: The microcontroller controls the on / off state of the high-pass equalizer of each bandpass filter amplifier circuit. At the same time, it combines the high-pass equalizer, gain module, adjustable digital anti-aliasing filter, differential driver and digital-to-analog converter of each bandpass filter amplifier circuit to simultaneously acquire underwater acoustic signals in four acquisition frequency bands. The gain levels include 60dB, 40dB, 30dB and 20dB.

[0022] In the above embodiments of this application, each bandpass filter amplifier circuit is independently controlled by a microcontroller unit to achieve synchronous acquisition of underwater acoustic signals in four frequency bands, avoiding signal loss caused by time-division sampling; combined with multiple gain levels (60dB / 40dB / 30dB / 20dB) and a high-pass equalizer, it adapts to the signal strength of different frequency bands and improves the signal-to-noise ratio of high and low frequency signals; the adjustable digital anti-aliasing filter and differential driver work together to suppress noise and ensure the purity of signals in each frequency band; the parallel architecture reduces data latency, and the digital-to-analog converter directly outputs digital signals, simplifying the subsequent storage and analysis process.

[0023] Optionally, the gain levels of different bandpass filter amplifier circuits decrease sequentially, with multiple gain levels from highest to lowest being the first high gain level, the second high gain level, the third high gain level, and the lowest gain level. In step 1031, the on / off state of the high-pass equalizer of each bandpass filter amplifier circuit is controlled by the microcontroller unit. Simultaneously, by combining the high-pass equalizer, gain module, adjustable digital anti-aliasing filter, differential driver, and digital-to-analog converter of each bandpass filter amplifier circuit, underwater acoustic signals from four acquisition frequency bands are simultaneously acquired, including: Step 10311: Close the high-pass equalizer in the bandpass filter amplifier circuit at the lowest gain level through the microcontroller unit.

[0024] Step 10312: For any bandpass filter amplifier circuit with a gain level higher than the lowest gain level, and the corresponding acquisition frequency band of the bandpass filter amplifier circuit, the original underwater acoustic signal located outside the acquisition frequency band is removed by a high-pass equalizer to obtain a filtered underwater acoustic signal; the filtered underwater acoustic signal is amplified to the detectable range of the digital-to-analog converter by a gain module to obtain an amplified underwater acoustic signal; the amplified underwater acoustic signal is filtered by an adjustable digital anti-aliasing filter to obtain a filtered underwater acoustic signal; the common-mode noise of the filtered underwater acoustic signal is suppressed by a differential driver to obtain a noise-filtered underwater acoustic signal; the noise-filtered underwater acoustic signal is downsampled by a digital-to-analog converter to obtain the digitized underwater acoustic signal of the acquisition channel corresponding to the bandpass filter amplifier circuit.

[0025] Step 10313: For the bandpass filter amplifier circuit with the lowest gain setting, the initial underwater acoustic signal collected by the hydrophone is directly amplified to the detectable range of the digital-to-analog converter through the gain module, and after passing through the adjustable digital anti-aliasing filter, differential driver and digital-to-analog converter, the digitized underwater acoustic signal of the acquisition channel corresponding to the bandpass filter amplifier circuit is obtained.

[0026] In the above embodiments of this application, simultaneous acquisition using four parallel bandpass filter amplifier circuits can cover a wide dynamic range. Specifically, the four bandpass filter amplifier circuits are, for example, CHA, CHB, CHC, and CHD, and the configuration of each bandpass filter amplifier circuit is as follows: CHA high gain (60dB, by Figure 1 It can be seen that (the sum of the 20dB common gain module in the hydrophone section and the 40dB gain module in the bandpass filter amplifier circuit) the high-pass equalizer is turned on; CHB medium gain (40dB=20dB+20dB), with high-pass equalizer on; CHC with low gain (30dB = 20dB + 10dB), and High-pass equalizer on; CHD low gain (20dB=20dB+0dB), high-pass equalizer closed.

[0027] Therefore, it is possible to collect full-band signals to cover a wide dynamic range.

[0028] Specifically, the microcontroller unit (MCU) intelligently manages four parallel bandpass filter amplifier circuit acquisition channels (the bandpass filter amplifier circuit, also known as CHA-CHD, employs differentiated signal processing strategies for different gain levels; the specific process is as follows:) 1. For the first high gain level, the second high gain level, and the third high gain level (e.g., CHA, CHB, CHC): The MCU keeps its high-pass equalizer on to precisely remove the raw underwater acoustic signal outside the target acquisition frequency band of this channel, resulting in a "filtered underwater acoustic signal." The signal is then amplified. A gain module amplifies the weak "filtered signal" to a level that the back-end circuitry (especially the digital-to-analog converter) can effectively process, resulting in an "amplified underwater acoustic signal." An adjustable digital anti-aliasing filter filters the amplified underwater acoustic signal to prevent spectral aliasing during subsequent sampling, resulting in a "filtered underwater acoustic signal." A differential driver suppresses common-mode noise introduced during signal transmission, improving signal quality, resulting in a "noise-filtered underwater acoustic signal." Finally, the digital-to-analog converter downsamples the clean analog signal, converting it into the final "digital underwater acoustic signal" for this acquisition channel.

[0029] 2. Bandpass filter amplifier circuit with the lowest gain setting (such as CHD): The MCU will close its high-pass equalizer. The signal processing flow is thus simplified: the "initial underwater acoustic signal" acquired by the hydrophone goes directly into the gain module for amplification, and then undergoes the same anti-aliasing filtering, noise suppression and digitization steps as the channels mentioned above.

[0030] Therefore, by applying the technical solution of this embodiment, the high-gain channel can focus on processing weak signals in a specific frequency band, avoiding low-frequency noise interference; while the low-gain channel is responsible for acquiring full-band signals that may contain large-amplitude low-frequency components without distortion. The combination of these two channels achieves synchronous high-fidelity acquisition of ultra-wide dynamic range full-band underwater acoustic signals.

[0031] Optionally, step 103, simultaneously acquiring underwater acoustic signals from four acquisition frequency bands through a parallel four-channel bandpass filter amplifier circuit, further includes: Step 1032: Configure the acquisition mode of the unique hydrophone. The acquisition mode includes a full-channel synchronous acquisition mode and a channel scene adjustment acquisition mode. The channel scene adjustment acquisition mode includes a deep-sea quiet water acquisition mode, a strong low-frequency noise environment acquisition mode, and a low-frequency application acquisition mode for earthquake monitoring.

[0032] Step 1033: If the only hydrophone is in full-channel synchronous acquisition mode, then the hydroacoustic signals of the four acquisition frequency bands are acquired simultaneously through the parallel four-channel bandpass filter amplifier circuit.

[0033] Step 1034: If the only hydrophone is in the deep-sea quiet water acquisition mode, the microcontroller activates the bandpass filter amplifier circuits of the first and second high gain levels and closes the high-pass equalizers of the bandpass filter amplifier circuits of the first and second high gain levels, so that the activated bandpass filter amplifier circuits can simultaneously acquire underwater acoustic signals in their respective acquisition frequency bands.

[0034] Step 1035: If the only hydrophone is in the strong low-frequency noise environment acquisition mode, the bandpass filter amplifier circuits of the second and third high gain levels are turned on through the microcontroller unit. At the same time, the high-pass equalizer of the bandpass filter amplifier circuit of the second high gain level is turned on, and the high-pass equalizer of the bandpass filter amplifier circuit of the third high gain level is turned off, so that the activated bandpass filter amplifier circuits can simultaneously acquire underwater acoustic signals in their respective acquisition frequency bands.

[0035] Step 1036: If the only hydrophone is in the low-frequency application acquisition mode for earthquake monitoring, the bandpass filter amplifier circuit at the lowest gain level is turned on through the microcontroller unit, and the high-pass equalizer of the bandpass filter amplifier circuit at the lowest gain level is also turned on, so that the bandpass filter amplifier circuit at the lowest gain level can acquire the underwater acoustic signal in the corresponding acquisition frequency band of the bandpass filter amplifier circuit at the lowest gain level.

[0036] In the above embodiments of this application, the marine background noise mainly consists of three parts: the first is ground sound, including broadband noise generated by natural processes such as wind and waves, rainfall, sea ice breaking, earthquakes and submarine volcanic activity; the second is biological sound, referring to various clicking, scraping and clicking sounds made by fish, crustaceans, marine mammals (such as whales and dolphins echolocation) and invertebrate larvae when foraging, socializing and navigating; the third is human-generated sound, which comes from human activities such as shipping (ship propellers and engines), oil and mineral exploration (sonar), offshore construction (wind power pile driving, drilling platforms), military exercises and blasting, as well as recreational boats and drones. Figure 3 The frequency bands of several ocean background noises are shown.

[0037] Specifically, the following acquisition configurations can be made for acquiring ocean acoustic signals in different frequency bands: 1. Full-channel synchronous acquisition mode, that is, four parallel bandpass filter amplifier circuits acquire data simultaneously.

[0038] 2. For adjusting the acquisition mode in a channel scenario, the following three types can be included: (1) Deep-sea quiet water acquisition mode, which can be used to collect fish acoustic signals: Enabling CHA (60dB) closes the Qualcomm equalizer, while simultaneously enabling CHB (40dB) closes the Qualcomm equalizer, which reduces power consumption but limits the dynamic range.

[0039] (2) The strong low-frequency noise environment acquisition mode is applicable in severe weather / dense ship environments: Enabling CHC (30dB) + High-pass equalizer (3200Hz high-pass filter) and simultaneously enabling CHD (20dB) + High-pass equalizer closed can suppress low-frequency saturation and preserve the integrity of high-frequency signals.

[0040] (3) Low-frequency application acquisition mode for earthquake monitoring: Only enable CHD (20dB) and use it with a high-pass equalizer. In particular, ensure that the ambient noise is higher than the device's noise floor. Configure the filter enable, sampling rate, gain level, and processing algorithm parameters via serial port commands. The device will start working automatically after being powered on and will output the results in real time or store them for later retrieval.

[0041] That is, by dynamically turning different bandpass filter amplifier circuits on / off and configuring the on / off state of their high-pass equalizers through the microcontroller unit, targeted signal acquisition can be achieved. More specifically: 1. Designed for collecting data in quiet deep-sea waters, suitable for environments with low background noise, it aims to efficiently collect weak acoustic signals emitted by organisms such as fish.

[0042] The MCU simultaneously enables the bandpass filter amplifier circuits for the first high-gain level (CHA, 40dB) and the second high-gain level (CHB, 20dB). The high-pass equalizers for both channels are then closed.

[0043] Because the two high-gain channels operate in parallel, they greatly amplify weak bio-acoustic signals, ensuring their effective capture. The closed equalizer prevents any signal (especially low-frequency components) from being filtered out, preserving the original acoustic characteristics to the maximum extent. This mode reduces the overall system power consumption by closing the other two channels while maintaining sensitivity.

[0044] 2. The acquisition mode is designed for strong low-frequency noise environments and is suitable for harsh weather or areas with dense shipping traffic. It aims to suppress strong low-frequency noise (such as waves and engine noise) and prevent amplifier saturation, thereby clearly extracting high-frequency signals.

[0045] The MCU simultaneously enables the bandpass filter amplifier circuits for the second high-gain level (CHB, 40dB) and the third high-gain level (CHC, 30dB). The high-pass equalizer for the CHB channel is enabled (for high-pass filtering), while the high-pass equalizer for the CHD channel is disabled.

[0046] Because the CHB channel effectively suppresses low-frequency interference through high-pass filtering, it focuses on acquiring and processing mid-to-high frequency signals that are not overwhelmed by noise. The CHD channel, as a low-gain backup, ensures that high-frequency signals with large amplitudes can also be recorded completely. Together, they extend the effective dynamic range of the underwater acoustic signal acquisition system in noisy environments.

[0047] 3. Designed specifically for monitoring extremely low-frequency acoustic signals generated by geological activities such as earthquakes, this system is designed for low-frequency applications in earthquake monitoring.

[0048] The MCU only enables the bandpass filter amplifier circuit at the lowest gain level (CHD, 20dB). Enable the high-pass equalizer for this channel (and configure it to an extremely low cutoff frequency, such as 3200Hz).

[0049] The low-gain setting ensures that the powerful low-frequency signal does not cause amplifier saturation. Simultaneously, enabling the high-pass equalizer filters out lower-frequency environmental noise or system background noise that may interfere with the target signal, thereby improving the signal-to-noise ratio and accuracy of extremely low-frequency seismic signal acquisition.

[0050] In summary, the microcontroller unit (MCU) can flexibly switch between multiple acquisition modes according to task requirements. By precisely controlling the opening and closing of channels at different gain levels and the state of its high-pass equalizer, the underwater acoustic signal acquisition system achieves multiple functions, from high-sensitivity capture of weak signals to extracting effective information from strong noise, and then to specializing in extremely low-frequency monitoring, significantly enhancing the equipment's adaptability and data acquisition quality in complex marine environments.

[0051] By employing a single hydrophone for signal acquisition, the technical solution of this embodiment saves space on the underwater glider platform. The low-power design enables long-term autonomous platform operation; the four-channel gain bandpass design allows for targeted acquisition of signals at different target frequency bands and sound pressure levels, achieving wide dynamic range and distortion-free acquisition; the combination of high-pass equalization and a programmable (adjustable digital) anti-aliasing low-pass filter balances low-frequency suppression and high-frequency fidelity; and the MCU (Microcontroller Unit) incorporates multiple signal detection algorithms, reducing backend computation and bandwidth requirements.

[0052] Furthermore, as Figure 1 In a specific implementation of the method, this application provides a hydrophone, which corresponds to an underwater acoustic signal acquisition system, such as... Figure 4 As shown, the underwater acoustic signal acquisition system includes: Signal acquisition module 201, signal processing module 202, control module 203 and information interaction module 204; The signal acquisition module 201 is used to acquire raw underwater acoustic signals and convert the acquired raw underwater acoustic signals into electrical signals; Signal processing module 202 is used to filter, amplify and digitize electrical signals to obtain digitized underwater acoustic signals; Control module 203 is used to control the signal acquisition module and the signal processing module; The information interaction module 204 is used to communicate with the main control system of the underwater glider.

[0053] In the above embodiments of this application, combined with Figure 2As shown, the signal acquisition module 201 is used to divide the acquired underwater acoustic signal into four channels. After internal analog conditioning and analog-to-digital conversion, the signal is stored in a large-capacity memory array, which is also the information interaction module. The internal signal processing module 202 performs real-time calculation and analysis of noise spectrum data to reduce the amount of noise information data. The processed noise spectrum data is sent to the main control system of the underwater glider. After the underwater glider surfaces, the noise spectrum data from each location is transmitted to the shore-based control center via satellite channel, so as to obtain the environmental noise field information on the underwater glider's operating profile in a near real-time manner.

[0054] The signal acquisition module 201 includes four parallel gain channels with different gains to cover a wide sound pressure range. A single-stage high-pass equalizer is used to suppress low-frequency saturation and improve high-frequency dynamics. The cutoff frequency of the adjustable digital anti-aliasing filter is controlled by the MCU clock frequency to adapt to different sampling rates and application requirements. Four-channel ADC (digital-to-analog converter) sampling is used, and the MCU incorporates various signal detection algorithms to output acoustic parameters in real time. Notably, the signal processing module 202 and control module 203 employ a DSP (Digital Signal Processor) with hardware FFT, enabling rapid spectral analysis of the signal to meet the system's real-time requirements.

[0055] Large-capacity storage array (corresponding) Figure 2 The data storage module can select a MicroSD card (i.e., a TF card) as the storage medium. For easier file management, a Fatfs file system can be installed on the storage medium. The information interaction module 204 communicates with the underwater glider's main control system via an RS232 interface, receiving commands from the main control system and sending processing results. The two parties can agree on a communication format of 1 start bit + 8 data bits + no parity bit + 1 stop bit, with a baud rate of 115200bps.

[0056] It should be noted that other corresponding descriptions of the functional units involved in the hydrophone provided in this application embodiment can be found by referring to... Figures 1 to 2 The corresponding descriptions in the method will not be repeated here.

[0057] Those skilled in the art will understand that the device structure provided in this embodiment does not constitute a limitation on the device, and may include more or fewer components, or combine certain components, or have different component arrangements.

[0058] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of a preferred embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing this application. Those skilled in the art will understand that the modules in the apparatus of the embodiment can be distributed within the apparatus of the embodiment as described, or can be modified to be located in one or more apparatuses different from this embodiment. The modules of the above-described embodiment can be combined into one module, or further divided into multiple sub-modules.

[0059] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any modifications that can be made by those skilled in the art should fall within the protection scope of this application.

Claims

1. A wide dynamic range underwater acoustic acquisition method suitable for underwater gliders, characterized in that, The wide dynamic range underwater acoustic acquisition method applicable to underwater gliders includes: For the single hydrophone, the single hydrophone is configured as a 4-channel parallel bandpass filter amplifier circuit; Each bandpass filter amplifier circuit is configured to a different acquisition frequency band. The configured unique hydrophone is installed on the underwater glider so that underwater sound acquisition is performed based on the installed unique hydrophone after the underwater glider is launched. When the single hydrophone is collecting underwater acoustic signals, it simultaneously collects underwater acoustic signals from four frequency bands through a parallel four-channel bandpass filter amplifier circuit. The underwater glider is also equipped with a memory array, and the underwater acoustic signals collected from each frequency band are independently stored in the corresponding memory unit of the memory array.

2. The wide dynamic range underwater acoustic acquisition method for underwater gliders according to claim 1, characterized in that, The configuration of the single hydrophone as a 4-channel parallel bandpass filter amplifier circuit includes: A bandpass filter amplifier circuit is constructed based on a high-pass equalizer, gain module, adjustable digital anti-aliasing filter, differential driver, and digital-to-analog converter. The unique hydrophone integrates a 4-channel parallel bandpass filter amplifier circuit.

3. The wide dynamic range underwater acoustic acquisition method for underwater gliders according to claim 2, characterized in that, A single hydrophone is used to acquire the initial underwater acoustic signal. This single hydrophone corresponds to a shared gain module for four bandpass filter amplifier circuits. Each bandpass filter amplifier circuit is controlled by the same microcontroller unit, and each bandpass filter amplifier circuit is configured with different gain levels. The gain corresponding to any gain level is provided jointly by the shared gain module and the gain module of the bandpass filter amplifier circuit itself. The simultaneous acquisition of underwater acoustic signals in four acquisition frequency bands through the four parallel bandpass filter amplifier circuits includes: The microcontroller controls the on / off state of the high-pass equalizer of each bandpass filter amplifier circuit, and simultaneously collects underwater acoustic signals from four acquisition frequency bands by combining the high-pass equalizer, gain module, adjustable digital anti-aliasing filter, differential driver and digital-to-analog converter of each bandpass filter amplifier circuit.

4. The wide dynamic range underwater acoustic acquisition method for underwater gliders according to claim 3, characterized in that, The gain levels of different bandpass filter amplifier circuits decrease sequentially, with multiple gain levels from highest to lowest being the first high gain level, the second high gain level, the third high gain level, and the lowest gain level. The microcontroller controls the on / off state of the gain modules of different bandpass filter amplifier circuits, and simultaneously, in conjunction with the high-pass equalizer, gain module, adjustable digital anti-aliasing filter, differential driver, and digital-to-analog converter of each bandpass filter amplifier circuit, it acquires underwater acoustic signals from four acquisition frequency bands, including: The high-pass equalizer in the bandpass filter amplifier circuit at the lowest gain level is closed by the microcontroller unit. For any bandpass filter amplifier circuit with a gain level higher than the lowest gain level, a high-pass equalizer removes the original underwater acoustic signal located outside the acquisition frequency band corresponding to the bandpass filter amplifier circuit, resulting in a filtered underwater acoustic signal. A gain module amplifies the filtered underwater acoustic signal to the detectable range of the digital-to-analog converter, resulting in an amplified underwater acoustic signal. An adjustable digital anti-aliasing filter filters the amplified underwater acoustic signal, resulting in a filtered underwater acoustic signal. A differential driver suppresses common-mode noise in the filtered underwater acoustic signal, resulting in a noise-filtered underwater acoustic signal. Finally, a digital-to-analog converter downsamples the noise-filtered underwater acoustic signal to obtain the digitized underwater acoustic signal of the acquisition channel corresponding to the bandpass filter amplifier circuit. For the bandpass filter amplifier circuit with the lowest gain setting, the initial underwater acoustic signal collected by the hydrophone is directly amplified to the detectable range of the digital-to-analog converter through the gain module. After passing through an adjustable digital anti-aliasing filter, a differential driver, and a digital-to-analog converter, the digitized underwater acoustic signal of the acquisition channel corresponding to the bandpass filter amplifier circuit is obtained.

5. The wide dynamic range underwater acoustic acquisition method for underwater gliders according to claim 4, characterized in that, The gain levels include 60dB, 40dB, 30dB, and 20dB.

6. The wide dynamic range underwater acoustic acquisition method for underwater gliders according to claim 2, characterized in that, Before simultaneously acquiring underwater acoustic signals from four frequency bands via parallel four-channel bandpass filtering and amplification circuits, the wide dynamic range underwater acoustic acquisition method suitable for underwater gliders further includes: Configure the acquisition mode of the unique hydrophone, wherein the acquisition mode includes a full-channel synchronous acquisition mode and a channel scene-adjustable acquisition mode; Accordingly, the simultaneous acquisition of underwater acoustic signals in four acquisition frequency bands via a parallel four-channel bandpass filter amplifier circuit includes: If the only hydrophone is in full-channel synchronous acquisition mode, then the underwater acoustic signals of four acquisition frequency bands are acquired simultaneously through parallel four-channel bandpass filter amplifier circuits.

7. The wide dynamic range underwater acoustic acquisition method for underwater gliders according to claim 6, characterized in that, The gain levels of different bandpass filter amplifier circuits decrease sequentially. The multiple gain levels, from largest to smallest, are the first high gain level, the second high gain level, the third high gain level, and the lowest gain level. The channel scene adjustment acquisition modes include deep-sea quiet water acquisition mode, strong low-frequency noise environment acquisition mode, and earthquake monitoring low-frequency application acquisition mode. The wide dynamic range underwater acoustic acquisition method applicable to underwater gliders also includes: If the only hydrophone is in the deep-sea quiet water acquisition mode, the microcontroller will turn on the bandpass filter amplifier circuits of the first and second high gain levels and close the high-pass equalizers of the bandpass filter amplifier circuits of the first and second high gain levels, so that the activated bandpass filter amplifier circuits can simultaneously acquire underwater acoustic signals in their respective acquisition frequency bands. If the only hydrophone is in the strong low-frequency noise environment acquisition mode, the microcontroller will turn on the bandpass filter amplifier circuits of the second and third high gain levels, turn on the high-pass equalizer of the bandpass filter amplifier circuit of the second high gain level, and close the high-pass equalizer of the bandpass filter amplifier circuit of the third high gain level, so that the activated bandpass filter amplifier circuits can simultaneously acquire underwater acoustic signals in their respective acquisition frequency bands. If the only hydrophone is in the low-frequency application acquisition mode for earthquake monitoring, the microcontroller will activate the bandpass filter amplifier circuit at the lowest gain level and the high-pass equalizer of the bandpass filter amplifier circuit at the lowest gain level, so that the bandpass filter amplifier circuit at the lowest gain level can acquire underwater acoustic signals in the corresponding acquisition frequency band.

8. A hydrophone, characterized in that, The hydrophone is used to implement the wide dynamic range underwater acoustic acquisition method for underwater gliders as described in any one of claims 1 to 7, and the hydrophone corresponds to an underwater acoustic signal acquisition system, the underwater acoustic signal acquisition system comprising: Signal acquisition module, signal processing module, control module, and information interaction module; The signal acquisition module is used to acquire raw underwater acoustic signals and convert the acquired raw underwater acoustic signals into electrical signals; The signal processing module is used to filter, amplify, and digitize electrical signals to obtain digitized underwater acoustic signals. The control module is used to control the signal acquisition module and the signal processing module; The information interaction module is used to communicate with the main control system of the underwater glider.

9. The hydrophone according to claim 8, characterized in that, The signal acquisition module is also used for: The underwater acoustic signals are simultaneously acquired from four frequency bands using parallel four-channel bandpass filter amplifier circuits, each of which is configured with a different acquisition frequency band.

10. The hydrophone according to claim 9, characterized in that, The underwater acoustic signal acquisition system also includes: The data storage module is used to store the underwater acoustic signals collected in four frequency bands. The power management module is used to provide power to the hydrophone.

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