Channel fading resistant river sound tomography signal control method

Abstract

The invention discloses an anti-channel-fading river sound tomography signal control method, which is used for controlling and adjusting the transceiving of sound wave signals in multiple aspects of time, sequence, type and intensity, and intelligently evaluating and screening the signal quality, so that the stability of the signals is ensured, and the measurement accuracy is improved. Comprising the following steps: (1) sending mutually orthogonal sound wave signals by each sound tomography station, and staggering the time of sending the sound wave signals by each sound tomography station; (2) measuring the lengths of a plurality of sounding lines among a plurality of sound tomography stations on the two sides of the river channel, and calculating the sound wave propagation time on the corresponding sounding lines; (3) transmitting and receiving sound wave signals by each sound tomography station in turn according to the control signal; and circularly executing the sound wave signal transmitting and receiving working process at weak, medium and strong signal transmitting powers, (4) the receiving end of the acoustic tomography system performs automatic gain control according to the received acoustic signal data; and (5) the acoustic signal data is intelligently evaluated and screened.

Description

Technical Field

[0001] The invention belongs to the field of intelligent processing of river flow monitoring data, and in particular relates to a river acoustic tomography signal control method resistant to channel fading. Background Art

[0002] River acoustic tomography flow measurement technology is a new river measurement technology with the advantages of easy installation and little influence by river surface conditions. Acoustic tomography technology calculates the flow rate of a river based on the characteristic that sound waves propagate faster in the downstream than in the upstream. The acoustic tomography flow measurement system uses an omnidirectional sound wave transmitting probe. The sound wave signal emitted by one probe can be received by multiple probes. The probes form an acoustic measurement line two by two, and finally form a multi-sound station measurement network. In order to ensure the stability of the sound wave signal, the acoustic tomography system needs to establish a set of signal control rules.

[0003] At present, the river acoustic tomography system has high requirements for the recognition accuracy of acoustic wave signals, and the recognition of acoustic wave signals is related to the signal strength. The strength of acoustic wave signals is affected by the hydroacoustic environment of the basin. Water level, water temperature, floating objects, ships, etc. will interfere with the propagation of sound waves. At the same time, there are factors that affect the acoustic wave signals in the acoustic tomography system itself. The same acoustic wave signals sent by different sound stations will interfere with each other, and the signal processing method at the receiving end will also have a great impact on signal recognition. Therefore, it is very important to study the control method of acoustic tomography signals against channel fading and interference.

[0004] Prior art, a water flow detection system based on acoustic tomography cross-section detection, application number CN202410695337.2, receives the reflected signal through the data processing unit, pre-processes the reflected signal to obtain the pre-processed signal; evaluates the quality of the pre-processed signal to obtain the evaluation result, dynamically adjusts the acoustic signal processing parameters according to the evaluation result to obtain the final pre-processed signal; extracts the pure signal and the noise signal from the pre-processed signal; calculates the variance of the noise signal, traverses all samples of the noise signal, calculates the difference between adjacent samples, and analyzes the final pre-processed signal according to the final pre-processed signal using the initial acoustic signal processing parameters and acoustic tomography technology to calculate the velocity distribution and flow rate. It is very difficult for this system and method to extract the pure signal and the noise signal, and the system processing algorithm sample training is complex and slow to respond. The impact of the underwater acoustic environment is not fully considered, and the signals sent by each acoustic tomography station are not processed differently, resulting in much interference.

[0005] Based on the previous research results, the research team of this invention further studied the impact of channel fading factors on signal strength and comprehensively improved the acoustic tomography signal control method. Summary of the invention

[0006] In order to solve the problem that the sound wave signals in the existing systems and river acoustic tomography flow measurement methods are easily interfered by various influencing factors, resulting in a large-scale channel attenuation, the present invention proposes a river acoustic tomography signal control method that is resistant to channel fading, which controls and adjusts the reception and transmission of sound wave signals in multiple dimensions such as time, sequence, type, and intensity, and performs intelligent evaluation and screening of signal quality to ensure signal stability and improve measurement accuracy.

[0007] The present invention provides a river acoustic tomography signal control method resistant to channel fading, comprising the steps of:

[0008] (1) Multiple acoustic tomography stations of an acoustic tomography system are arranged on both sides of the river channel, each acoustic tomography station sends mutually orthogonal acoustic wave signals, and the time at which each acoustic tomography station sends the acoustic wave signal is staggered;

[0009] (2) Measure the lengths of multiple acoustic lines between multiple acoustic tomography stations on both sides of the river channel and calculate the sound wave propagation time on the corresponding acoustic lines;

[0010] (3) Each acoustic tomography station takes turns to send and receive acoustic wave signals according to the control signal; the above-mentioned acoustic wave signal sending and receiving process is cyclically performed with three signal sending powers of weak, medium and strong;

[0011] (4) The receiving end of the acoustic tomography system performs automatic gain control according to the received acoustic wave signal data, forming a large-cycle control process of sending and receiving with a fixed time period, so that the intensity of the received acoustic wave signal is at a relatively stable level;

[0012] (5) Each acoustic tomography station uploads the received acoustic wave signal to the acoustic tomography system control platform, performs intelligent evaluation and screening on the acoustic wave signal data, screens out unqualified data, reduces the impact of noise in the signal, extracts effective signal feature information, fuses the calculation results, and performs subsequent flow calculations.

[0013] Furthermore, step (1) specifically includes: by setting each acoustic tomography station to send mutually orthogonal acoustic wave signals, and staggering the time for each acoustic tomography station to send acoustic wave signals, mutual interference between different acoustic wave signals is avoided, thereby achieving channel separation and noise reduction.

[0014] Further, step (3) specifically includes: measuring and obtaining the sound wave data of the longest time length that each acoustic tomography station can receive each time, and the time required to send / receive a complete sound wave signal, starting from the first acoustic tomography station, controlling at a first set time, the first acoustic tomography station switches from the sending state to the receiving state, and the second acoustic tomography station switches from the receiving state to the transmitting state; subsequent acoustic tomography stations sequentially perform the working conversion of the sending and receiving states to form a complete signal receiving and sending process of the acoustic tomography system, and calculating the duration of the complete signal receiving and sending process of the acoustic tomography system.

[0015] Specifically, the duration of a complete signal receiving and sending process of the acoustic tomography system needs to be determined according to factors that affect the sound wave propagation time, such as the measuring line distance, the water temperature variation range, the equipment mode switching time, and the number of acoustic tomography stations.

[0016] Furthermore, the acoustic tomography system controls each acoustic tomography station to send three different transmission power levels of weak, medium and strong acoustic wave signals in turn, thereby ensuring that appropriate signals can be received in different underwater acoustic environments and improving signal data quality; at the same time, the acoustic tomography system receiving end will automatically perform gain control according to the received signal strength to ensure the stability of the received acoustic wave signal data.

[0017] Furthermore, in step (5), the acoustic wave signal data is intelligently evaluated and screened, specifically including the following sub-steps: 1) during the non-signal transmission period, each acoustic tomography station receives river noise background data and calculates the noise intensity level; measurement signals are sent at different acoustic tomography stations in the river channel, and the received acoustic wave signals are calculated and analyzed from three dimensional reference quantities to obtain signal quality evaluation;

[0018] 2) according to the signal quality evaluation, the flow results obtained under the acoustic wave signal data are calculated using the acoustic tomography data processing method, and compared with the cruise ADCP flow data to calculate the corresponding errors;

[0019] 3) performing a correlation test on the reciprocal of the error and each signal evaluation value to obtain corresponding evaluation index values;

[0020] 4) Calculate the weight of each scoring result according to the evaluation index value Take a weighted average of each scoring result to finally get the comprehensive score of the sound wave signal This is used to evaluate the strength of the sound wave signal and conduct screening.

[0021] Furthermore, in the sub-step 1), the three-dimensional reference quantities of the acoustic tomography signal refer to the signal-to-noise ratio, pulse shape similarity matching degree, and concentration analysis of the signal, and the acoustic wave signal is scored respectively.

[0022] The following introduces the technical advantages brought by the system and method of the present invention by comparing with the prior art:

[0023] 1) The strength of underwater acoustic signals is greatly affected by the hydroacoustic environment of the basin. Water level, water temperature, bottom sediment or aquatic plants will interfere with the propagation of sound waves. The acoustic tomography stations of the existing system are arranged at a fixed distance in the river. There is no uniform rule for sending acoustic signals from different acoustic tomography stations. Moreover, the same acoustic signals sent will interfere with each other, the channel attenuation is large, and it is difficult for the receiving end to accurately identify and measure the acoustic signals.

[0024] The present invention specifically controls and sets the type, sequence, time, and transmission power of the sound wave signal emitted by each sound tomography station according to the different distributions and distances of multiple sound tomography stations, and correspondingly sets the time for receiving the sound wave signal, performs quality control on the received signal data, and finally fuses the calculation results to obtain accurate and stable flow measurement results.

[0025] The present invention controls multiple acoustic tomography stations to send mutually orthogonal signals. Since the mutual correlation of mutually orthogonal signals is zero, different signals will only be identified as background noise during signal recognition, and the recognition ability of normal signals will not be reduced. Therefore, mutual interference between signals is reduced to a minimum level, and no misrecognition will occur, thereby achieving channel separation and noise reduction.

[0026] 2) Taking into account the influence of water level, water temperature, bottom sediment, and surface ship navigation of different rivers, the penetration and conduction effects of sound waves of different powers are different. The method of the present invention controls the acoustic tomography station to send signals with three levels of power: weak, medium, and strong. The signal receiving and sending process of the entire acoustic tomography station is cyclically executed. Finally, all data are integrated for quality evaluation and screening, which greatly reduces external interference noise.

[0027] The method of the present invention uses the receiving end to perform automatic gain control according to the received sound wave signal data, and finally forms a complete cycle of receiving and transmitting. The change of the transmission power and the automatic gain value of the data are both intelligent and dynamic control. The system uses an AGC circuit, and automatically controls the gain circuit according to the strength of the received sound wave signal, and transmits different voltage signals to the MCU for collection, so as to ensure that the strength of the received sound wave signal is at a more stable level, which is 4-7% higher in stability than the existing method.

[0028] 3) The method of the present invention performs intelligent evaluation and screening of sound wave signal data, overcoming the shortcomings of the existing single evaluation method of sound information intensity. By combining the advantages of multiple basic evaluation methods, and simultaneously performing correlation tests on the inverses of multiple evaluation calculation errors and various signal quality evaluation indicators, the differences in evaluation values ​​of different magnitudes are integrated to achieve the unity of various evaluation indicators. Finally, a weighted average is taken for each evaluation index value, which greatly reduces the error and improves the accuracy and scientificity of the evaluation. It is found through experiments that the measurement accuracy is improved by 6-9% compared with the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the layout of multiple acoustic chromatography stations of the present invention.

[0030] Figure 2 It is a schematic diagram of the sequence of transmitting and receiving sound wave signals by multiple acoustic tomography stations of the present invention.

[0031] Figure 3 The figure is a circuit diagram of the system of the present invention for controlling different transmission powers.

[0032] Figure 4 The present invention sends three levels of sound wave signals and performs automatic gain control on the received signal strength.

[0033] Figure 5 A schematic diagram of the process of screening signal data according to the present invention. DETAILED DESCRIPTION

[0034] The technical solution in the embodiment of the invention will be clearly and completely described below in conjunction with the drawings in this embodiment.

[0035] The present invention provides a river acoustic tomography signal control method resistant to channel fading. The method controls and adjusts the time, sequence, type, power and other aspects of the acoustic wave signal emitted by each acoustic tomography station according to the distribution and distance of the acoustic tomography stations, and sets the time for receiving the acoustic wave signal accordingly, performs quality control on the received signal data, and integrates and comprehensively analyzes the calculation results to obtain accurate and stable flow measurement results.

[0036] Embodiment 1 of the present invention provides a river acoustic tomography signal control method that resists channel fading, which is applicable to acoustic tomography site measurement of multiple acoustic stations in an acoustic tomography system, and does not limit the number of acoustic tomography sites. The following takes four acoustic tomography sites as an example, and the layout of the acoustic tomography sites is as follows: Figure 1 , from upstream to downstream of the river, they are numbered A, B, C, and D respectively. The arrows indicate the direction of the river. The following describes how to control the signal reception and processing process of this station.

[0037] The method of the present invention comprises the steps of (1) configuring a plurality of acoustic tomography stations of an acoustic tomography system on both sides of a river channel, each acoustic tomography station sending mutually orthogonal acoustic wave signals, and staggering the time at which each acoustic tomography station sends the acoustic wave signals. For example, 4 acoustic tomography stations are configured to send 4 mutually orthogonal acoustic wave signals. Since the mutual correlation of mutually orthogonal signals is 0, during signal recognition, different signals will only be recognized as background noise, and the recognition ability of normal signals will not be reduced. Therefore, the signals will not interfere with each other, causing misrecognition, thereby achieving channel separation and noise reduction.

[0038] Step (2) measures the lengths of multiple acoustic detection lines between multiple acoustic tomography stations on both sides of the river channel, and calculates the sound wave propagation time on the corresponding acoustic detection lines.

[0039] Measure the length d of the four acoustic lines AB, AD, BC, and CD AB d AD d BC d CD , the sound wave propagation time t on the four sound detection lines is estimated by the sound speed v and the distance formula d = vt AB ,t AD ,t BC ,t CD . Assume that the length of the acoustic test line is within 6 kilometers and the propagation time does not exceed 4 seconds.

[0040] Step (3) Each acoustic tomography station takes turns to send and receive acoustic wave signals according to the control signal; the acoustic wave signal sending and receiving process is cyclically executed with three signal sending powers of weak, medium and strong.

[0041] Assume that the acoustic tomography station can receive acoustic wave data of t seconds at most each time, and it takes t0 seconds to send / receive a complete acoustic wave signal. Starting from acoustic tomography station A, a sound wave signal is sent, and acoustic tomography stations B and D are respectively and Receiving starts at 10 seconds, and at 4 seconds, acoustic tomography station A switches from the sending state to the receiving state, and acoustic tomography station B switches from the receiving state to the transmitting state.

[0042] See also Figure 2 , at the 5th second after the acoustic tomography station A sends the signal, the acoustic tomography station B starts to send the sound wave signal. The acoustic tomography stations A and C calculate the receiving time according to the formula and receive the signal sent by the acoustic tomography station B. At the 9th second, the acoustic tomography stations B and C switch the receiving and sending status. Starting from the 10th second, the acoustic tomography station C sends the sound wave signal, and the acoustic tomography stations B and D receive the signal. At the 14th second, the acoustic tomography stations C and D switch the receiving and sending status. Starting from the 15th second, the acoustic tomography station D sends the sound wave signal, and the acoustic tomography stations A and C receive the signal. At the 19th second, the acoustic tomography stations D and A switch the receiving and sending status. The above is a complete signal sending and receiving process of the acoustic tomography system, which takes a total of 20 seconds.

[0043] Each acoustic tomography station takes turns to send three different transmission power levels of weak, medium and strong acoustic signals, and cyclically executes the above signal transmission and reception process to ensure that appropriate signals can be received in different underwater acoustic environments and improve the signal data quality. The receiving end automatically performs gain control based on the received acoustic signal data, and finally forms a large cycle of acoustic signal transmission and reception with a period of 1 minute.

[0044] Specifically, the duration of a complete signal transmission and reception process of the acoustic tomography system needs to be determined according to the factors that affect the sound wave propagation time, such as the distance of the measuring line, the range of water temperature changes, the equipment mode switching time, and the number of acoustic tomography stations. The duration can be adaptively adjusted. For sites with longer measuring lines, more time intervals need to be reserved. Changes in water temperature and water level will affect the change in sound wave propagation time. Switching between the probe sending mode and the receiving mode also takes some time.

[0045] In step (4), the receiving end of the acoustic tomography system performs automatic gain control according to the received acoustic wave signal data, forming a large-cycle control process of sending and receiving with a fixed time period, so that the intensity of the received acoustic wave signal is at a relatively stable level.

[0046] The change of transmission power and the automatic gain value of data are realized by the acoustic tomography system. It can be realized by hardware circuit, see Figure 3 By controlling the combination of relay 1 and relay 2, the different ratios of transformer T3 are controlled to achieve the transformation of three different transmission powers: weak, medium and strong. The system uses an AGC circuit to automatically control the gain of the circuit according to the strength of the received sound wave signal, and transmits different voltage signals to the MCU for collection after gaining them, ensuring that the strength of the received sound wave signal is at a relatively stable level.

[0047] Step (5) Each acoustic tomography station uploads the received acoustic wave signal to the acoustic tomography system control platform, performs intelligent evaluation and screening on the acoustic wave signal data, screens out unqualified data, reduces the impact of noise in the signal, extracts effective signal feature information, fuses the calculation results, and performs subsequent flow calculations.

[0048] Specifically, it includes the following sub-steps: 1) During the non-signal transmission period, each acoustic tomography station receives river noise background data and calculates the noise intensity level; sends measurement signals at different acoustic tomography stations in the river, and calculates and analyzes the received acoustic wave signals from three dimensional reference quantities to obtain signal quality evaluation. The three dimensional reference quantities of the acoustic tomography signal refer to the signal-to-noise ratio, pulse shape similarity matching, and concentration analysis of the signal, and the acoustic wave signals are scored respectively.

[0049] 2) according to the signal quality evaluation, the flow results obtained under the acoustic wave signal data are calculated using the acoustic tomography data processing method, and compared with the cruise ADCP flow data to calculate the corresponding errors;

[0050] When calculating the signal-to-noise ratio of the analysis signal, the received acoustic tomography signal is calculated using the signal-to-noise ratio formula Calculate the signal-to-noise ratio of the signal, where P represents the average power of the signal, which can also be represented by the symbol S; N represents the average power of the noise. The signal-to-noise ratio algorithm can evaluate the strength of the signal relative to the noise. The larger the signal-to-noise ratio, the better the signal strength.

[0051] When using pulse shape similarity matching analysis, that is, template matching filter analysis, the pure signal data is used as a template, and the pure signal data itself is subjected to a template matching filter algorithm to obtain the matching result of the two. Since the data itself matches itself, a theoretical ideal matching value will be obtained. The larger the template matching filter result value, the more similar the template is to the matched object. When the received sound signal is the same as the sent measurement signal, the most ideal signal data will be obtained.

[0052] The template matching filtering result of the received acoustic tomography signal is respectively subjected to template matching filtering operation again with the matching result of the pure signal data to obtain the matching result of the data, which indicates the reception status of the acoustic tomography signal;

[0053] Then, the ideal matching value is used as a template, and a template matching filter operation is performed on the actual matching result to obtain the matching degree of the two; if the matching result value is higher, the acoustic tomography signal reception condition is closer to the ideal condition, and the signal strength is better.

[0054] When calculating the concentration of the analysis signal, the contour curve of the signal matching filter result is fitted with the normal distribution curve to obtain the normal distribution curve fitting result. In this way, the acoustic tomography signal processing can quickly locate the strong signal gathering place, improve the contrast with the background noise signal, and thus improve the success rate of accurate signal analysis.

[0055] 3) Perform a correlation test on the inverse of the error and each signal evaluation value to obtain the corresponding evaluation index values. Since the magnitudes of the evaluation values ​​obtained by the above three sub-evaluation methods are quite different, the study found that in actual calculations, it is necessary to remove the magnitude differences of each score before performing data fusion, which can eliminate errors to the greatest extent.

[0056] 4) Calculate the weight of each scoring result according to the evaluation index value Take a weighted average of each scoring result to finally get the comprehensive score of the sound wave signal This is used to evaluate the strength of the sound wave signal and conduct screening.

[0057] For details of the above step (5), please refer to the research results previously disclosed by our R&D team, namely the patent titled "An Intelligent Processing and Evaluation Method for Acoustic Tomography Signal Intensity Data", which will not be repeated here.

[0058] The method of the present invention ensures the stability and reliability of subsequent calculations by filtering out unqualified data. At the same time, since acoustic tomography adopts an oversampling method to collect data, the number of data samples is much larger than the number of output results. Therefore, the acoustic tomography system control platform can obtain a representative data from a set of filtered data by averaging calculation to perform subsequent flow velocity calculation. This processing can further reduce the influence of noise in the signal, extract signal feature information, and thus improve the accuracy of the calculation results.

[0059] The method of the present invention brings many technical advantages. By setting each sound station to send mutually orthogonal sound wave signals and staggering the time for each sound station to send sound wave signals, mutual interference between different signals is avoided, and channel separation and noise reduction are achieved.

[0060] Since the propagation of sound wave signals is greatly affected by the underwater acoustic environment, water level, water temperature, sand content, etc. will affect the strength of the sound wave signal. If the signal strength is too small, it will be unrecognizable, and if it is too large, it will cause serious reverberation interference. Therefore, the method of the present invention sends three levels of sound wave signals with different transmission powers in turn to ensure that appropriate signals can be received in different underwater acoustic environments and improve the signal data quality. The receiving end will automatically control the gain according to the received signal strength to ensure that the received signal data is stable and not affected by the underwater acoustic environment.

[0061] See also Figure 4 The test waveform is the result of sending three different power levels of sound wave signals and automatically controlling the received signal strength. The tick in the figure indicates the selected transmission power. It can be seen that after sending three levels of sound wave signals, the received signal data waveform is stable.

[0062] The present invention uses evaluation indicators for acoustic tomography sound wave signals to perform quality control on the collected sound wave signal data, screens out affected data, and calculates representative data through mathematical statistical methods, thereby greatly reducing the impact of noise on the signal and improving the accuracy and stability of the results.

[0063] Through experimental testing, the process of screening signal data can be found in Figure 5 The check mark in the figure indicates the selected signal waveform. The final processed signal waveform is more accurate and stable.

Claims

1. A river acoustic tomography signal control method resistant to channel fading, characterized in that: Includes steps: (1) Multiple acoustic tomography stations of an acoustic tomography system are arranged on both sides of the river channel, each acoustic tomography station sends mutually orthogonal acoustic wave signals, and the time at which each acoustic tomography station sends the acoustic wave signal is staggered; (2) Measure the lengths of multiple acoustic lines between multiple acoustic tomography stations on both sides of the river channel and calculate the sound wave propagation time on the corresponding acoustic lines; (3) Each acoustic tomography station takes turns to send and receive acoustic wave signals according to the control signal; the above-mentioned acoustic wave signal sending and receiving process is cyclically performed with three signal sending powers of weak, medium and strong; (4) The receiving end of the acoustic tomography system performs automatic gain control according to the received acoustic wave signal data, forming a large-cycle control process of sending and receiving with a fixed time period, so that the intensity of the received acoustic wave signal is at a relatively stable level; (5) Each acoustic tomography station uploads the received acoustic wave signal to the acoustic tomography system control platform, performs intelligent evaluation and screening on the acoustic wave signal data, screens out unqualified data, reduces the impact of noise in the signal, extracts effective signal feature information, fuses the calculation results, and performs subsequent flow calculations.

2. The method for controlling river acoustic tomography signals against channel fading according to claim 1, characterized in that: Step (1) specifically includes: by setting each acoustic tomography station to send mutually orthogonal acoustic wave signals, and staggering the time for each acoustic tomography station to send acoustic wave signals, mutual interference between different acoustic wave signals is avoided, thereby achieving channel separation and noise reduction.

3. The method for controlling river acoustic tomography signals against channel fading according to claim 1, characterized in that: Step (3) specifically includes: The acoustic wave data of the longest receiving time length of each acoustic tomography station is measured, and the time required to send / receive a complete acoustic wave signal is controlled to start from the first acoustic tomography station, and at a first set time, the first acoustic tomography station switches from the sending state to the receiving state, and the second acoustic tomography station switches from the receiving state to the transmitting state; the subsequent acoustic tomography stations sequentially perform the working conversion of the sending and receiving states to form a complete signal receiving and sending process of the acoustic tomography system, and the duration of the complete signal receiving and sending process of the acoustic tomography system is calculated.

4. The method for controlling river acoustic tomography signals against channel fading according to claim 3 is characterized in that: The duration of a complete signal transmission and reception process of the acoustic tomography system needs to be determined according to factors that affect the sound wave propagation time, such as the distance of the measuring line, the range of water temperature variation, the equipment mode switching time, and the number of acoustic tomography stations.

5. The method for controlling river acoustic tomography signals against channel fading according to claim 1, characterized in that: The acoustic tomography system controls each acoustic tomography station to send three different transmission power levels of weak, medium and strong acoustic wave signals in turn, thereby ensuring that appropriate signals can be received in different underwater acoustic environments and improving signal data quality; the acoustic tomography system receiving end will automatically perform gain control according to the received signal strength to ensure that the received acoustic wave signal data is stable.

6. The method for controlling river acoustic tomography signals against channel fading according to claim 1, characterized in that: In step (5), the acoustic wave signal data is intelligently evaluated and screened, which specifically includes the following sub-steps: 1) During the non-signal transmission period, each acoustic tomography station receives river noise background data and calculates the noise intensity level; measurement signals are sent at different acoustic tomography stations in the river, and the received sound wave signals are calculated and analyzed from three dimensional reference quantities to obtain signal quality evaluation; 2) according to the signal quality evaluation, the flow results obtained under the acoustic wave signal data are calculated using the acoustic tomography data processing method, and compared with the cruise ADCP flow data to calculate the corresponding errors; 3) performing a correlation test on the reciprocal of the error and each signal evaluation value to obtain corresponding evaluation index values; 4) Calculate the weight of each scoring result according to the evaluation index value Take a weighted average of each scoring result to finally get the comprehensive score of the sound wave signal This is used to evaluate the strength of the sound wave signal and conduct screening.

7. The method for intelligent processing and evaluation of acoustic tomography signal intensity data according to claim 6, characterized in that: In the sub-step 1), the three-dimensional reference quantities of the acoustic tomography signal refer to the signal-to-noise ratio, pulse shape similarity matching degree, and concentration analysis of the signal, and the acoustic wave signal is scored respectively.

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