Amplitude-phase joint sounding method and system based on DSP

Abstract

The invention provides an amplitude-phase joint sounding method based on a DSP, and relates to the technical field of multi-beam sounding, the method is realized through a multi-core DSP chip, the multi-core DSP chip adopts a master-slave architecture, a master core is responsible for overall control, each slave core is responsible for data processing of a corresponding beam angle, and the method comprises the following steps: when the beam angle is smaller than a preset threshold value, determining that the beam angle is smaller than the preset threshold value; a WMT amplitude sounding method is realized through a multi-core DSP chip, and the WMT amplitude sounding method utilizes amplitude energy information of a beam signal to estimate echo round-trip time; when the beam angle is larger than a preset threshold value, the sub-array phase difference sounding method is achieved through the multi-core DSP chip, and the echo round-trip time is estimated through the phase difference time sequence zero crossing point position of the beam signals in the sub-array phase difference sounding method. By adopting the scheme, accurate and reliable measurement results can be obtained in different environments.

Description

Technical Field

[0001] This application relates to the technical field of multi-beam sounding, and particularly to an amplitude-phase joint sounding method and system based on DSP. Background Art

[0002] As an important part of the earth, the ocean contains extremely rich natural resources. The development of ocean resources usually depends on accurate seabed terrain information. Traditional sounding equipment is limited by its measurement accuracy and efficiency and cannot meet the growing needs of ocean exploration work. People need sounding equipment with higher detection accuracy and efficiency and a wider detection range. The multi-beam sounding system has the advantages of high precision and high efficiency, and can achieve fine measurement of the seabed topography and geomorphology. It not only provides key data support for the exploration, development and utilization of ocean resources, but also can assist in environmental monitoring and assessment, providing a scientific basis for ocean ecological protection.

[0003] As the core algorithm of the multi-beam sounding system, the underwater sounding algorithm not only determines the performance upper limit of the multi-beam sounding system, but also directly affects the accuracy and efficiency of seabed topography mapping. Summary of the Invention

[0004] This application aims to at least solve one of the technical problems in the related art to some extent.

[0005] To this end, the first object of this application is to propose an amplitude-phase joint sounding method based on DSP, which can obtain accurate and reliable measurement results in different environments.

[0006] The second object of this application is to propose an amplitude-phase joint sounding system based on DSP.

[0007] To achieve the above object, the first aspect embodiment of this application proposes an amplitude-phase joint sounding method based on DSP. This method is implemented by a multi-core DSP chip. The multi-core DSP chip adopts a master-slave architecture. The master core is responsible for overall control, and each slave core is responsible for data processing of the corresponding beam angle. The method includes:

[0008] When the beam angle is less than a preset threshold, the WMT amplitude sounding method is implemented by the multi-core DSP chip. Among them, the WMT amplitude sounding method estimates the round-trip time of the echo using the amplitude energy information of the beam signal;

[0009] When the beam angle is greater than the preset threshold, the sub-array phase difference sounding method is implemented by the multi-core DSP chip. Among them, the sub-array phase difference sounding method estimates the round-trip time of the echo using the zero-crossing position of the phase difference time series of the beam signal.

[0010] Optionally, in an embodiment of the present application, the multi-core DSP chip implements the transfer of inter-core messages through IPC interrupts and realizes the synchronization of multi-core data processing by using shared memory.

[0011] Optionally, in an embodiment of the present application, implementing the WMT amplitude sounding method includes:

[0012] Estimate the echo time based on the echo angle, and set an echo time window based on the estimated echo time;

[0013] Use the bisection iteration method to search for the maximum energy range. In each iteration search, trisect the current frame data, compare the sum of the energy values of each divided interval, determine the interval with the maximum energy, and use this interval to replace the original search range. Repeat the iteration process until the length of the final interval is less than the set echo time window;

[0014] After searching for the echo arrival time range, calculate the echo arrival time value according to the centroid method.

[0015] Optionally, in an embodiment of the present application, implementing the sub-array phase difference sounding method includes:

[0016] Use the separated aperture method to obtain the beamforming result data of two sub-arrays;

[0017] Conjugately multiply the two sub-arrays and perform sliding smoothing processing to obtain the data after sliding processing;

[0018] Find the phase of the data after sliding processing to obtain the phase difference sequence;

[0019] Calculate the time range of the beam echo arrival according to the beam angle, and use this range as the estimated interval of the echo arrival time;

[0020] Perform quadratic curve fitting on the phase difference data within the estimated interval, calculate the zero crossing point of the quadratic curve, and use the corresponding moment of this point as the echo arrival time value.

[0021] To achieve the above object, an embodiment of the second aspect of the present invention proposes an amplitude-phase joint sounding system based on DSP, which is used for:

[0022] When the beam angle is less than the preset threshold, implement the WMT amplitude sounding method through a multi-core DSP chip. Among them, the multi-core DSP chip adopts a master-slave architecture, the master core is responsible for overall control, and each slave core is responsible for data processing corresponding to the beam angle. The WMT amplitude sounding method estimates the round-trip time of the echo by using the amplitude energy information of the beam signal;

[0023] When the beam angle is greater than a preset threshold, a subarray phase difference sounding method is implemented through a multi-core DSP chip. Among them, the subarray phase difference sounding method estimates the round-trip time of the echo using the zero-crossing position of the phase difference time series of the beam signal.

[0024] Optionally, in an embodiment of the present application, the multi-core DSP chip uses the IPC interrupt method to implement the transmission of inter-core messages and uses the shared memory method to synchronize multi-core data processing.

[0025] Optionally, in an embodiment of the present application, a WMT amplitude sounding method is implemented, including:

[0026] Estimate the echo time based on the echo angle and set an echo time window based on the estimated echo time;

[0027] Use the bisection iteration method to search for the maximum energy range. In each iteration search, divide the current frame data into three equal parts, compare the sum of the energy values of each divided interval, determine the interval with the maximum energy, and use this interval to replace the original search range. Repeat the iteration process until the length of the final interval is less than the set echo time window;

[0028] After searching for the echo arrival time range, calculate the echo arrival time value according to the centroid method.

[0029] Optionally, in an embodiment of the present application, a subarray phase difference sounding method is implemented, including:

[0030] Use the separated aperture method to obtain the beamforming result data of two subarrays;

[0031] Conjugate multiply the two subarrays and perform sliding smoothing processing to obtain the data after sliding processing;

[0032] Obtain the phase difference sequence by calculating the phase of the data after sliding processing;

[0033] Calculate the time range of the beam echo arrival according to the beam angle and use this range as the estimated interval of the echo arrival time;

[0034] Perform quadratic curve fitting on the phase difference data within the estimated interval and calculate the zero-crossing point of the quadratic curve. Use the moment corresponding to this point as the echo arrival time value.

[0035] The amplitude-phase joint sounding method and system based on DSP in the embodiments of the present application adopt the WMT amplitude detection method when the beam angle is less than the preset threshold, accurately calculate the arrival time of the echo using the amplitude information of the signal, adopt the phase difference method when the beam angle is greater than the preset threshold, and determine the arrival time of the echo by detecting the moment when the phase difference is zero. During the sounding process, the algorithm is automatically switched according to the angle size of the echo signal to ensure accurate and reliable measurement results in different environments; the engineering implementation of the underwater sounding algorithm is completed using the multi-core synchronous processing method on the DSP chip, and the program design of the algorithm is completed using several cores of the DSP in the master-slave model. Among them, the master core is responsible for the overall control of the entire program, and the slave cores are respectively responsible for the data processing of different beam angles in the amplitude-phase joint sounding algorithm. This processing method improves the processing speed of the underwater sounding algorithm and ensures the real-time performance and efficiency of the sounding system.

[0036] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present application. Brief Description of the Drawings

[0037] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of the embodiments in conjunction with the drawings, where:

[0038] Figure 1 is a schematic flowchart of a method for amplitude-phase joint sounding based on DSP provided in Embodiment 1 of the present application;

[0039] Figure 2 is a diagram of the task allocation of each core of the DSP in the embodiment of the present application;

[0040] Figure 3 is a flowchart of the program implementation of the amplitude detection method in the embodiment of the present application;

[0041] Figure 4 is a flowchart of the program implementation of the phase detection method in the embodiment of the present application;

[0042] Figure 5 is an example diagram of the detection results of the WMT method and the phase difference method in the embodiment of the present application. Detailed Embodiments

[0043] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application.

[0044] The amplitude-phase joint sounding method and system based on DSP according to the embodiments of the present application will be described below with reference to the accompanying drawings.

[0045] Figure 1 FIG. 4 is a schematic flowchart of an amplitude-phase joint sounding method based on DSP provided in Embodiment 1 of the present application. This method is implemented by a multi-core DSP chip. The multi-core DSP chip adopts a master-slave architecture. The master core is responsible for overall control, and each slave core is responsible for data processing of corresponding beam angles.

[0046] As Figure 1 shown, the amplitude-phase joint sounding method based on DSP includes the following steps:

[0047] Step 101, when the beam angle is less than a preset threshold, implement the WMT amplitude sounding method through the multi-core DSP chip. Among them, the WMT amplitude sounding method estimates the round-trip time of the echo using the amplitude energy information of the beam signal;

[0048] In this embodiment, to ensure the real-time performance of the sounding algorithm processing, the engineering implementation of the underwater sounding algorithm is completed on the DSP chip using a multi-core synchronous processing method. The program design of the algorithm is completed using 5 cores of the DSP in a master-slave model. Among them, 1 master core is responsible for the overall control of the entire program, and 4 slave cores are respectively responsible for data processing of different beam angles in the amplitude-phase joint sounding algorithm. This processing method improves the processing speed of the underwater sounding algorithm and ensures the real-time performance and efficiency of the sounding system.

[0049] In this embodiment, considering that the system has a large number of beams and the calculation logic of the sounding algorithm is relatively complex, to ensure real-time performance, a multi-core TMS320C6678 chip of TI is selected as the multi-core DSP chip, and its multi-core function is used to complete the sounding algorithm processing operation.

[0050] In this embodiment, the program processing is carried out in a master-slave mode. Core0 serves as the master core and is responsible for managing the data transmission between other devices and scheduling tasks for the slave cores. Core1-Core4 serve as slave cores. The main function is to share the calculation tasks of the underwater sounding algorithm, and the algorithms processed by each slave core are the same. To improve the calculation efficiency, according to the different beam angles, the calculation tasks are assigned to different slave cores. Core1 is responsible for calculating the arrival time of the 1st to 128th beams, Core2 is responsible for calculating the 129th to 256th beams, and so on. The working tasks of each core in the DSP program design are as Figure 2 shown.

[0051] In this embodiment, during the DSP multi-core processing, there is data transfer and message interaction between cores. TMS320C6678 has multiple methods to achieve fast inter-core data and message transfer, including shared memory space, semaphores, and IPC interrupts, etc. This embodiment uses the IPC interrupt method to achieve inter-core message transfer. This method allows different cores to transfer information through interrupt signals. When a core needs to send a message to another core, the sending core will first trigger an IPC interrupt, and the receiving core will perform corresponding processing after receiving the interrupt, thereby achieving inter-core message transfer. In addition, this embodiment also uses the shared memory method to achieve the synchronization of multi-core data processing. By reasonably partitioning and managing the shared memory, it can ensure that each core of the DSP can maintain synchronization when processing data, avoiding data inconsistency or conflict situations.

[0052] In this embodiment, when the angle is less than 15°, the WMT amplitude detection method is adopted. The WMT method uses the amplitude energy information of the beam signal to estimate the round-trip time of the echo. The program design process of the WMT method in the DSP is as Figure 3 shown:

[0053] (1) First, estimate the echo time based on the echo angle, and set a specific echo time window according to this estimate. The echo time window calculation formula:

[0054]

[0055] where τ is the pulse duration, θ 0 =α + sin -1 (λk / dM), k = -M / 2 + 1:M / 2, α is the array tilt angle, l is the beam number, λ is the wavelength, d is the element spacing, c is the sound speed, M can take 2 - 2.5 times the number of array elements, H is the water depth, θ R is the 3dB main beam width, θ 0 is the preformed beam angle.

[0056] (2) Then, use the dichotomy iteration method to search for the maximum energy range, that is, divide a frame of data [x 0 , x N into three intervals [ω 1 , ω 2 , [ω 2 , ω 3 , [ω 3 , ω 4 , and determine the interval with the maximum energy by comparing the sum of the energy values of the three different intervals. Assume that the data after beamforming is Data_I(x) and Data_Q(x), then the energy in these three intervals is:

[0057] E 1 =∑Data_I2 (x) + Data_Q 2 (z), x ∈ [ω 1 , ω 2

[0058] E 2 = ∑Data_I 2 (x) + Data_Q 2 (x), x ∈ [ω 2 , ω 3

[0059] E 3 = ∑Data_I 2 (x) + Data_Q 2 (x), x ∈ [ω 3 , ω 4

[0060] (3) After determining the interval with the maximum energy, immediately replace the original search range with this interval and repeat the above iterative process until the length of the finally obtained interval is less than the preset echo time window. After finding the echo arrival time range, calculate the echo arrival time value according to the centroid method. The echo arrival time calculation formula is:

[0061]

[0062] where A(n) is the amplitude at time t(n) in the region with the maximum energy.

[0063] Step 102, when the beam angle is greater than the preset threshold, implement the sub-array phase difference sounding method through a multi-core DSP chip. Among them, the sub-array phase difference sounding method estimates the round-trip time of the echo using the zero-crossing position of the phase difference time series of the beam signal.

[0064] In this embodiment, when it is greater than 15°, the phase difference method is adopted. The sub-array phase difference detection method uses the zero-crossing position of the phase difference time series of the beam signal to estimate the round-trip time of the echo. The program design flow of the sub-array phase difference detection method in the DSP is as Figure 4 shown:

[0065] (1) First, use the method of separated apertures to obtain the beamforming result data S A (k, n) and S B (k, n), where k represents different beam numbers. Sub-array A is composed of the first M array elements (M is less than the total number of array elements), and sub-array B is composed of the last M array elements.

[0066] (2) Subsequently, conjugate multiply the two sub-arrays Then perform sliding smoothing processing on S AB (k, n): ​​​

[0067]

[0068] Among them, L w represents the length of the sliding window, and ω(n) is the weighting coefficient.

[0069] (3) After that, the phase difference sequence can be obtained by calculating the phase of the data after sliding processing

[0070] (4) Immediately afterwards, calculate the time range when the beam echo arrives according to the beam angle, and take this range as the estimation interval of TOA.

[0071] (5) Finally, perform quadratic curve fitting on the phase difference data within the estimation interval, and further calculate the zero crossing point of the quadratic curve. The moment corresponding to this point is the echo arrival time value.

[0072] In the amplitude-phase joint sounding method based on DSP in the embodiments of the present application, when the beam angle is less than the preset threshold, the WMT amplitude detection method is adopted to accurately calculate the arrival time of the echo by using the amplitude information of the signal. When the beam angle is greater than the preset threshold, the phase difference method is adopted to determine the arrival time of the echo by detecting the moment when the phase difference is zero. During the sounding process, the algorithm is automatically switched according to the angle size of the echo signal to ensure accurate and reliable measurement results in different environments; the engineering implementation of the underwater sounding algorithm is completed by using the multi-core synchronous processing method on the DSP chip. The program design of the algorithm is designed to use several cores of the DSP in the master-slave model. Among them, the master core is responsible for the overall control of the entire program, and the slave cores are respectively responsible for the data processing of different beam angles in the amplitude-phase joint sounding algorithm. This processing method improves the processing speed of the underwater sounding algorithm and ensures the real-time performance and efficiency of the sounding system.

[0073] This embodiment demonstrates the effect of the amplitude-phase joint sounding algorithm and the time performance of using DSP multi-core synchronization processing through simulation and testing. The experimental simulation conditions are set as a water depth of 100 meters and a seawater sound speed of 1500 m / s. The transmitted signal is a pulse signal with a frequency of 200 kHz and a duration of 0.003 s. The system sampling frequency is 400 KHz, and the element spacing of the receiving array is half a wavelength. Verify the effects of the WMT method and the sub-array phase difference method.

[0074] Figure 5The comparison of the detection results of the WMT detection method and the sub-array phase difference method in the simulation experiment under different angle conditions is shown. As can be seen from the figure, in the angle range of 0° and its adjacent areas, the echo signals received by the receiving array have a relatively large amplitude. At this time, applying the WMT algorithm can achieve a relatively satisfactory detection efficiency. However, as the angle of the detection target gradually deviates from the central area, the detection efficiency of the WMT algorithm also decreases. In the edge beam area, the phase difference detection algorithm shows better detection performance. But when the detection area is close to the central beam, the detection error of the phase difference detection method increases significantly.

[0075] To implement the above embodiments, the present application also proposes an amplitude-phase joint sounding system based on DSP, and this system is used for:

[0076] When the beam angle is less than the preset threshold, the WMT amplitude sounding method is implemented through a multi-core DSP chip. Among them, the multi-core DSP chip adopts a master-slave architecture, the master core is responsible for overall control, and each slave core is responsible for data processing of the corresponding beam angle. The WMT amplitude sounding method estimates the round-trip time of the echo using the amplitude energy information of the beam signal;

[0077] When the beam angle is greater than the preset threshold, the sub-array phase difference sounding method is implemented through a multi-core DSP chip. Among them, the sub-array phase difference sounding method estimates the round-trip time of the echo using the zero-crossing position of the phase difference time series of the beam signal.

[0078] Optionally, in an embodiment of the present application, the multi-core DSP chip uses the IPC interrupt method to implement the transfer of inter-core messages and uses the shared memory method to achieve the synchronization of multi-core data processing.

[0079] Optionally, in an embodiment of the present application, implementing the WMT amplitude sounding method includes:

[0080] Estimate the echo time based on the echo angle, and set the echo time window based on the estimated echo time;

[0081] Adopt the iterative method of dichotomy to search for the maximum energy range. In each iterative search, the current frame data is divided into three equal parts, and the sum of the energy values of each divided interval is compared to determine the interval with the maximum energy, and use this interval to replace the original search range, and repeat the iterative process until the length of the final interval is less than the set echo time window;

[0082] After the echo arrival time range is searched, the echo arrival time value is calculated according to the centroid method.

[0083] Optionally, in an embodiment of the present application, implementing the sub-array phase difference sounding method includes:

[0084] Use the separated aperture method to obtain the beamforming result data of two sub-arrays;

[0085] Multiply the two sub-arrays conjugately and perform sliding smoothing processing to obtain the data after sliding processing;

[0086] Find the phase of the data after sliding processing to obtain the phase difference sequence;

[0087] Calculate the time range when the beam echo arrives according to the beam angle, and use this range as the estimated interval of the echo arrival time;

[0088] Perform quadratic curve fitting on the phase difference data within the estimated interval, calculate the zero-crossing point of the quadratic curve, and use the moment corresponding to this point as the echo arrival time value.

[0089] It should be noted that the foregoing explanation of the embodiment of the amplitude-phase joint sounding method based on DSP is also applicable to the amplitude-phase joint sounding system based on DSP in this embodiment, and will not be elaborated here.

[0090] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0091] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0092] Any process or method description shown in the flowchart or described in other ways herein can be understood as representing a module, segment or part of code including one or more executable instructions for implementing a customized logic function or process, and the scope of the preferred embodiment of the present application includes additional implementations, where the functions may be executed in a substantially simultaneous manner or in a reverse order according to the involved functions, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0093] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in conjunction with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpretation, or otherwise processing as appropriate, and then storing it in a computer memory.

[0094] It should be understood that various parts of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), and the like.

[0095] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the method of implementing the above embodiments can be completed by a program instructing relevant hardware, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0096] In addition, each functional unit in various embodiments of the present application may be integrated into one processing module, or each unit may exist physically alone, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0097] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A DSP-based amplitude-phase joint depth sounding method, characterized in that: The method is implemented by a multi-core DSP chip, which adopts a master-slave architecture, where the master core is responsible for overall control and each slave core is responsible for data processing corresponding to the beam angle. The method includes: When the beam angle is less than a preset threshold, the WMT amplitude sounding method is implemented through a multi-core DSP chip, wherein the WMT amplitude sounding method estimates the echo round-trip time using the amplitude energy information of the beam signal; When the beam angle is greater than a preset threshold, a subarray phase difference depth measurement method is implemented through a multi-core DSP chip, wherein the subarray phase difference depth measurement method estimates the echo round-trip time by using the zero-crossing point position of the phase difference time series of the beam signal.

2. The method according to claim 1, characterized in that The multi-core DSP chip uses an IPC interrupt mode to implement inter-core message transmission, and uses a shared memory mode to implement multi-core data processing synchronization.

3. The method according to claim 1, characterized in that Implementing the WMT amplitude sounding method includes: estimating an echo time based on an echo angle, and setting an echo time window based on the estimated echo time; The search for the maximum energy range is performed by using a binary search iteration method. In each iterative search, the current frame data is divided into three equal parts, and the energy values ​​of each divided interval are compared to determine the interval with the maximum energy. This interval is used to replace the original search range, and the iterative process is repeated until the final interval length is less than the set echo time window. After searching the echo arrival time range, the echo arrival time value is calculated according to the centroid method.

4. The method according to claim 1, characterized in that Implementing the sub-array phase difference depth measurement method includes: The beamforming result data of two sub-arrays are obtained by using the split aperture method; The two sub-arrays are conjugate-multiplied and subjected to sliding smoothing processing to obtain the data after sliding processing; The phase of the data after sliding processing is calculated to obtain a phase difference sequence; Calculate the time range of beam echo arrival according to the beam angle, and use the range as the estimated interval of echo arrival time; A quadratic curve is fitted to the phase difference data within the estimation interval, and the zero-crossing point of the quadratic curve is calculated, and the time corresponding to the point is taken as the echo arrival time value.

5. A DSP-based amplitude-phase joint depth sounding system, characterized in that: The system is used to: When the beam angle is less than a preset threshold, the WMT amplitude sounding method is implemented through a multi-core DSP chip, wherein the multi-core DSP chip adopts a master-slave architecture, the master core is responsible for overall control, and each slave core is responsible for data processing corresponding to the beam angle. The WMT amplitude sounding method estimates the echo round-trip time using the amplitude energy information of the beam signal; When the beam angle is greater than a preset threshold, a subarray phase difference depth measurement method is implemented through a multi-core DSP chip, wherein the subarray phase difference depth measurement method estimates the echo round-trip time by using the zero-crossing point position of the phase difference time series of the beam signal.

6. The system according to claim 1, characterized in that The multi-core DSP chip uses an IPC interrupt mode to implement inter-core message transmission, and uses a shared memory mode to achieve synchronization of multi-core data processing.

7. The system according to claim 1, characterized in that Implementing the WMT amplitude sounding method includes: estimating an echo time based on an echo angle, and setting an echo time window based on the estimated echo time; The search for the maximum energy range is performed by using a binary search iteration method. In each iterative search, the current frame data is divided into three equal parts, and the energy values ​​of each divided interval are compared to determine the interval with the maximum energy. This interval is used to replace the original search range, and the iterative process is repeated until the final interval length is less than the set echo time window. After searching the echo arrival time range, the echo arrival time value is calculated according to the centroid method.

8. The system of claim 1, wherein: Implementing the sub-array phase difference depth measurement method includes: The beamforming result data of two sub-arrays are obtained by using the split aperture method; The two sub-arrays are conjugate-multiplied and subjected to sliding smoothing processing to obtain the data after sliding processing; The phase of the data after sliding processing is calculated to obtain a phase difference sequence; Calculate the time range of beam echo arrival according to the beam angle, and use the range as the estimated interval of echo arrival time; A quadratic curve is fitted to the phase difference data within the estimation interval, and the zero-crossing point of the quadratic curve is calculated, and the time corresponding to the point is taken as the echo arrival time value.

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