Underwater topographic survey system and method

Abstract

The invention discloses an underwater topographic measurement system and method, and particularly relates to the field of underwater topographic measurement, and the underwater topographic measurement system comprises a depth measurement module, a positioning module, an environment monitoring module and a data processing and transmission module. The depth measurement module is provided with a plurality of high-precision acoustic sensors, and corresponding water depth data is calculated by combining a hybrid beam sounding technology; the positioning module integrates a satellite positioning system and an inertial navigation system and is used for positioning work; the environment monitoring module comprises a water temperature sensor, a water quality sensor and a water flow speed sensor and is used for monitoring the environment; and the data processing and transmission module is used for processing and transmitting a large amount of data transmitted by the depth measurement module, the positioning module and the environment monitoring module in real time. The measuring range can be effectively improved, and the measuring precision is high.

Description

Technical Field

[0001] The present invention relates to the field of underwater topography measurement, and more specifically, to an underwater topography measurement system and method. Background Art

[0002] Underwater topography measurement is of vital importance to many fields such as marine resource development, port construction, channel dredging, water conservancy projects and marine scientific research. Traditional underwater topography measurement methods mainly rely on single-beam echo sounders or multi-beam echo sounders, combined with positioning systems (such as GPS) to obtain underwater terrain elevation information and location information.

[0003] However, these traditional methods have some limitations. For example, the measurement range of single-beam echo sounders is relatively narrow and the measurement efficiency is low; although multi-beam echo sounders have a wider measurement range, the equipment cost is high and the data processing is complex. In addition, in complex underwater environments, such as areas with strong water currents, large amounts of suspended matter, or dense underwater obstacles, the measurement accuracy and reliability of traditional measurement systems will be greatly affected. Moreover, existing underwater topographic measurement systems often lack the ability to comprehensively monitor underwater environmental parameters (such as water temperature, water quality, water flow velocity, etc.), and cannot provide sufficient information support for the comprehensive planning and implementation of underwater projects.

[0004] In order to solve the above problems, a technical solution is now provided. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide an underwater topography measurement system and method to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An underwater topography measurement system, comprising: a depth measurement module, a positioning module, an environment monitoring module and a data processing and transmission module;

[0008] The depth measurement module is equipped with multiple high-precision acoustic sensors and combines hybrid beam bathymetry technology to calculate the corresponding water depth data;

[0009] The positioning module integrates satellite positioning system and inertial navigation system for positioning work;

[0010] The environmental monitoring module includes a water temperature sensor, a water quality sensor and a water flow velocity sensor, which are used to monitor the environment;

[0011] The data processing and transmission module is used to process and transmit the large amount of data sent by the depth measurement module, positioning module and environmental monitoring module in real time.

[0012] In a preferred embodiment, the operation process of the depth measurement module includes the following:

[0013] The acoustic sensors are arranged in an array and are distributed at different angles and positions of the measuring equipment. Each sensor has an independent signal acquisition and preprocessing circuit, which is used to amplify and filter the weak electrical signals received by the acoustic sensor.

[0014] Hybrid beam sounding technology includes wide beam transmission and narrow beam reception, and the transmission beam angle is set to 80 degrees.

[0015] In a preferred embodiment, the operation process of the depth measurement module further includes the following:

[0016] When the wide beam transmits the acoustic signal, the sound wave propagates in the water and reflects back after hitting the bottom of the water. Multiple high-precision acoustic sensors receive the reflected echo signal and first time-stamp the signal to record the time interval t from the emission of the sound wave to the reception.

[0017] Calculate the water depth using the formula:

[0018] Among them, h is the water depth and v is the speed of sound waves in water.

[0019] In a preferred embodiment, the operation process of the positioning module includes the following contents:

[0020] Using differential positioning technology, satellite signals are received at a base station with a known precise position, and the error difference between the satellite signals received by the measuring device is calculated. These error differences are transmitted to the satellite positioning system of the measuring device. The measuring device uses these error correction information to correct the position coordinates calculated by itself.

[0021] The inertial measurement unit consists of an accelerometer and a gyroscope, and uses an inertial navigation algorithm to calculate the position based on the acceleration and angular velocity data provided.

[0022] In a preferred embodiment, the operation process of the positioning module also includes the following contents:

[0023] The Kalman filter algorithm is used to fuse satellite positioning data and inertial navigation data, integrating the high-precision position information of the satellite positioning system and the high-frequency attitude and speed information of the inertial navigation system;

[0024] During the fusion process, the weights of satellite positioning data and inertial navigation data are dynamically adjusted according to the signal quality of the satellite positioning system and the number of visible satellites.

[0025] In a preferred embodiment, the operation process of the environment monitoring module includes the following:

[0026] Water quality sensors include dissolved oxygen sensors, pH sensors and turbidity sensors.

[0027] In a preferred embodiment, the operation process of the data processing and transmission module includes the following contents:

[0028] Equipped with multiple high-speed data interfaces, it can simultaneously receive data from the depth measurement module, positioning module and environmental monitoring module;

[0029] Perform a preliminary integrity check on the received data, including packet header and packet tail check and data length verification;

[0030] The data of each module is calibrated according to the calibration parameters pre-stored in the system. For the depth measurement module, the measurement error of the acoustic sensor is corrected using the data of a standard pool or calibration area with known depth, including sound velocity compensation;

[0031] The satellite positioning data is corrected using the differential information provided by the ground reference station, and the accelerometer and gyroscope errors of the inertial navigation system are calibrated by comparing with reference points with known precise positions and attitudes;

[0032] The environmental monitoring module calibrates the sensor based on the measured values ​​in standard solutions or standard environments.

[0033] An underwater topography measurement method, comprising an underwater topography measurement system as described in any one of the above, comprising the following steps:

[0034] Step S1: Equipped with multiple high-precision acoustic sensors, combined with hybrid beam bathymetry technology, the corresponding water depth data is calculated;

[0035] Step S2: integrating a satellite positioning system and an inertial navigation system for positioning;

[0036] Step S3: using a water temperature sensor, a water quality sensor and a water flow velocity sensor to monitor the environment;

[0037] Step S4: Process and transmit in real time the large amount of data transmitted from the depth measurement module, the positioning module and the environment monitoring module.

[0038] The technical effects and advantages of the underwater topography measurement system and method of the present invention are as follows:

[0039] 1. The acoustic sensor of the present invention adopts an array layout and each sensor is equipped with an independent signal acquisition and preprocessing circuit. On the one hand, it can cover the underwater space in all directions and capture the terrain details. On the other hand, it can amplify and filter weak electrical signals, effectively remove noise interference, and improve the signal-to-noise ratio, thereby laying the foundation for accurate water depth measurement. It can more accurately distinguish the slight ups and downs and changes of underwater terrain. In the hybrid beam bathymetry technology, wide beam transmission (80-degree transmission beam angle) can cover a larger water area and use multi-path reflection signals to obtain more terrain information; while narrow beam reception can reduce the interference of the surrounding environment and improve the measurement accuracy. In addition, by accurately recording the time interval from sound wave transmission to reception, the water depth data can be accurately obtained based on factors such as sound speed. As a whole, high-precision water depth measurement can be achieved, which is conducive to accurately depicting the true appearance of the underwater terrain.

[0040] 2. The wide-beam transmission in the hybrid beam bathymetry technology of the depth measurement module of the present invention can cover a larger water area at one time. When conducting topographic measurements of large underwater areas, the number of times the measuring equipment is moved and the measuring path can be reduced compared to traditional methods, and the approximate water depth distribution of the water area can be quickly obtained, which significantly improves the measurement efficiency. This is especially advantageous in the preliminary survey of unknown water terrain, and the macroscopic features of the underwater terrain can be determined more quickly, saving time for subsequent detailed measurements.

[0041] 3. The inertial navigation system in the positioning module of the present invention relies on its own inertial measurement unit to work, and does not rely on external satellite signals. It can still normally calculate the position in special environments where satellite signals are blocked (such as under underwater bridges, in tunnels, etc.) or interfered with, and the communication network cannot cover it, thereby achieving continuous positioning, enhancing the adaptability of the entire measurement system in complex environments and the stability of positioning, ensuring the correct matching of measurement data and position information, and allowing the measurement work to be carried out smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The figure is a schematic structural diagram of an underwater topographic measurement system of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] Figure 1The present invention provides an underwater topography measurement system, comprising: a depth measurement module, a positioning module, an environment monitoring module and a data processing and transmission module;

[0046] The depth measurement module is equipped with multiple high-precision acoustic sensors and combines hybrid beam bathymetry technology to calculate the corresponding water depth data;

[0047] The positioning module integrates satellite positioning system and inertial navigation system for positioning work;

[0048] The environmental monitoring module includes a water temperature sensor, a water quality sensor and a water flow velocity sensor, which are used to monitor the environment;

[0049] The data processing and transmission module is used to process and transmit the large amount of data sent by the depth measurement module, positioning module and environmental monitoring module in real time.

[0050] The operation process of the depth measurement module includes the following:

[0051] The acoustic sensors are arranged in an array and are distributed at different angles and positions of the measuring equipment. Each sensor has an independent signal acquisition and preprocessing circuit, which is used to amplify and filter the weak electrical signals received by the acoustic sensor.

[0052] Hybrid beam sounding technology includes wide beam transmission and narrow beam reception, and the transmission beam angle is set to 80 degrees.

[0053] It should be added that the acoustic sensors are arranged in an array, distributed at different angles and positions, and can achieve full coverage of the underwater space. This is like setting up multiple "observation points" underwater, so that echo signals can be obtained from multiple directions no matter how complex the underwater terrain is. For example, when measuring underwater reef areas with irregular shapes or curved underwater rivers, it can effectively avoid the terrain information that is missed due to single-direction measurement, thereby more comprehensively depicting the true appearance of the underwater terrain.

[0054] This layout is conducive to capturing detailed changes in underwater terrain. Sensors at different locations can sense tiny terrain undulations. By comprehensively analyzing the data from each sensor, smaller terrain height differences can be distinguished, improving the resolution of underwater terrain measurement. For example, when measuring shoals or dredged areas at the bottom of port channels, the boundaries and depth changes of shoals can be determined more accurately, providing more accurate data support for channel maintenance.

[0055] Each sensor is equipped with an independent signal acquisition and pre-processing circuit, which can amplify and filter weak electrical signals. Due to the complex underwater environment, the echo signals received by the acoustic sensor are usually weak and easily interfered by noise. The independent amplification circuit can enhance the signal strength, making subsequent signal processing and analysis easier. Just like when listening to a weak radio signal, using an amplifier to increase the volume makes the sound clearer and more discernible.

[0056] The transmission beam angle is set to 80 degrees, which can cover a large area of ​​water at one time. When measuring large areas of underwater topography, such as measuring an entire lake or a large area of ​​sea, this wide beam transmission method can reduce the number of times the measuring equipment is moved and the measurement path. Compared with narrow beam transmission, it can obtain preliminary water depth data for a wider area in a shorter time, thereby significantly improving measurement efficiency. It is like sweeping the floor with a wide broom, which can sweep a larger area at a time without having to change the position of the broom frequently.

[0057] The operation process of the depth measurement module also includes the following:

[0058] When the wide beam transmits the acoustic signal, the sound wave propagates in the water and reflects back after hitting the bottom of the water. Multiple high-precision acoustic sensors receive the reflected echo signal and first time-stamp the signal to record the time interval t from the emission of the sound wave to the reception.

[0059] Calculate the water depth using the formula:

[0060] Among them, h is the water depth and v is the speed of sound waves in water.

[0061] It should be added that time-stamping the reflected echo signal and accurately recording the time interval from the emission to the reception of the sound wave provide a high-precision data basis for water depth measurement. Because the propagation speed of sound waves in water is relatively stable (under certain water temperature, salinity and other conditions), by accurately recording the time interval, this key parameter can be used to calculate the exact distance, that is, the water depth. This time-based measurement method can achieve very high accuracy. For example, in modern high-precision acoustic measurement equipment, the time measurement accuracy can reach the nanosecond level, so that depth changes in centimeters or even smaller units can be distinguished.

[0062] Time stamping helps distinguish signals from different reflection sources. In a complex underwater environment, sound waves may be reflected from multiple places, such as the bottom of the water, suspended objects in the water, and surrounding obstacles. With accurate time stamping, it is possible to determine whether different reflected signals come from the bottom of the water or other interfering objects based on their arrival time. For example, signals reflected directly from the bottom of the water usually arrive at the sensor first, while signals reflected from distant suspended objects arrive later, so that effective signals that are truly used to calculate water depth can be screened out.

[0063] As long as the two parameters of sound wave propagation speed and time interval can be accurately obtained, reliable water depth data can be obtained. Moreover, the propagation speed of sound waves in water is relatively stable under certain conditions. For example, in waters where temperature and salinity do not change much, the speed fluctuation is small. This means that in actual measurements, as long as the propagation speed is properly calibrated (taking into account the influence of factors such as water temperature and salinity), this simple formula can be used to continuously calculate the water depth, providing stable depth data output for underwater topography measurement.

[0064] The operation process of the positioning module includes the following:

[0065] Using differential positioning technology, satellite signals are received at a base station with a known precise position, and the error difference between the satellite signals received by the measuring device is calculated. These error differences are transmitted to the satellite positioning system of the measuring device. The measuring device uses these error correction information to correct the position coordinates calculated by itself.

[0066] The inertial measurement unit consists of an accelerometer and a gyroscope, and uses an inertial navigation algorithm to calculate the position based on the acceleration and angular velocity data provided.

[0067] It should be added that high-precision positioning is crucial in underwater topographic measurement. Differential positioning technology can improve positioning accuracy from ordinary meters to centimeters or even higher. For example, in scenarios such as precise measurement of port channels and precise location determination of underwater buildings (such as bridge piers and submarine pipelines), centimeter-level positioning accuracy can accurately depict the location and boundaries of objects, thereby providing reliable data support for engineering construction, maintenance, and safety assessment.

[0068] It effectively overcomes the influence of some major error sources in satellite positioning systems. Satellite signals are affected by atmospheric refraction, satellite clock errors and other factors during propagation, which can lead to deviations in positioning results. Differential positioning receives satellite signals through the base station and measurement equipment at the same time, and compares the error difference between the two, which can accurately correct these common errors and greatly improve the accuracy of positioning.

[0069] Differential positioning can reduce the impact of satellite signal obstruction or interference to a certain extent. In some complex measurement environments, such as near high-rise buildings, mountainous areas, or underwater areas where objects block satellite signals, satellite positioning signals may fluctuate or be interrupted. Through differential positioning technology, even if the quality of satellite signals decreases, the error correction information transmitted by the base station can still maintain relatively stable and accurate positioning results, reducing jumps and abnormalities in positioning data.

[0070] This technology makes the positioning results of the surveying equipment more consistent and repeatable. When measuring at different times or in different weather conditions, as long as the base station can work normally and accurately transmit the error difference, the surveying equipment can obtain stable and high-precision positioning data, which is conducive to long-term underwater terrain monitoring and comparative analysis.

[0071] The accelerometers and gyroscopes in the inertial measurement unit (IMU) can provide real-time acceleration and angular velocity data of the measuring device. The inertial navigation algorithm based on this data can realize continuous estimation of the position when the satellite positioning signal is blocked or lost. For example, when the survey ship enters an area where satellite signals cannot cover, such as under an underwater bridge or in a tunnel, the inertial navigation system can continuously calculate the position of the measuring device based on the previous motion state and changes in acceleration and angular velocity, ensuring that the positioning data will not be interrupted, and providing a complete data chain for underwater terrain measurement.

[0072] The operation process of the positioning module also includes the following:

[0073] The Kalman filter algorithm is used to fuse satellite positioning data and inertial navigation data, integrating the high-precision position information of the satellite positioning system and the high-frequency attitude and speed information of the inertial navigation system;

[0074] During the fusion process, the weights of satellite positioning data and inertial navigation data are dynamically adjusted according to the signal quality of the satellite positioning system and the number of visible satellites.

[0075] It should be added that the Kalman filter algorithm can make the best estimate of the position, speed, attitude and other states of the measuring equipment based on the measurement accuracy, error characteristics and real-time measurement data of the two positioning systems (satellite positioning and inertial navigation). This means that it can make full use of the high-precision position information of the satellite positioning system and the high-frequency attitude and speed information of the inertial navigation system, combining the advantages of both to obtain a more accurate comprehensive positioning result than using either system alone. For example, the satellite positioning system is more accurate in determining the position, while the inertial navigation system is more sensitive to changes in attitude and speed in a short period of time. After fusion through the Kalman filter, it can reflect the dynamic changes of the measuring equipment more timely while ensuring the position accuracy.

[0076] It can effectively handle the noise and uncertainty in both positioning systems. Satellite positioning data may be affected by factors such as satellite signal fluctuations and multipath effects, generating random noise; inertial navigation data may cause cumulative errors due to sensor errors (such as zero bias and drift of accelerometers and gyroscopes). The Kalman filter algorithm models the dynamic model and measurement model of the system, reasonably allocates weights, filters and corrects these noises and uncertainties, and thus provides a more stable and reliable positioning estimate.

[0077] During underwater topographic surveying, the measurement environment is complex and changeable. The signal quality of the satellite positioning system may change due to factors such as weather (such as clouds, rainfall, etc.), surrounding obstacles (such as mountains, large buildings), or water surface reflection. By dynamically adjusting the data weight according to the signal quality of the satellite positioning system and the number of visible satellites, the positioning system can better adapt to these changes. For example, in open waters, good weather and strong satellite signals, the weight of satellite positioning data is increased to obtain high-precision location information; in areas where satellite signals are blocked or interfered, such as near islands or where there are large structures underwater, the weight of inertial navigation data is appropriately increased to ensure the continuity and reliability of positioning.

[0078] Dynamically adjusting weights can optimize the overall performance of the positioning system. By reasonably allocating the weights of satellite positioning data and inertial navigation data, it is possible to maximize the advantages of the two positioning systems while ensuring positioning accuracy, and avoid performance degradation caused by over-reliance on one system. For example, when the satellite positioning system is working properly, its high-precision position information is fully utilized to reduce the impact of the cumulative error of the inertial navigation system; when the satellite positioning system fails or its performance degrades, it is promptly switched to the inertial navigation system to ensure the basic positioning function.

[0079] The operation process of the environmental monitoring module includes the following:

[0080] Water quality sensors include dissolved oxygen sensors, pH sensors and turbidity sensors.

[0081] The operation process of the data processing and transmission module includes the following:

[0082] Equipped with multiple high-speed data interfaces, it can simultaneously receive data from the depth measurement module, positioning module and environmental monitoring module;

[0083] Perform a preliminary integrity check on the received data, including packet header and packet tail check and data length verification;

[0084] The data of each module is calibrated according to the calibration parameters pre-stored in the system. For the depth measurement module, the measurement error of the acoustic sensor is corrected using the data of a standard pool or calibration area with known depth, including sound velocity compensation;

[0085] The satellite positioning data is corrected using the differential information provided by the ground reference station, and the accelerometer and gyroscope errors of the inertial navigation system are calibrated by comparing with reference points with known precise positions and attitudes;

[0086] The environmental monitoring module calibrates the sensor based on the measured values ​​in standard solutions or standard environments.

[0087] It should be added that the data from different modules can be better synchronized in time. Because these data can be received at the same time, the water depth, position and environmental information at the same time can be recorded more accurately. For example, when drawing a three-dimensional image of underwater terrain, the position information and water depth information at the same time need to be matched. If the data reception is not synchronized, it will cause deviations or errors in the image, and multi-interface reception helps to avoid this situation.

[0088] For the depth measurement module, using the data of a standard pool or calibration area with known depth to correct the measurement error of the acoustic sensor, especially the sound velocity compensation, can greatly improve the accuracy of water depth measurement. Because the speed of sound in water will change due to factors such as water temperature and salinity, calibration can accurately compensate for the speed of sound according to actual environmental conditions. For example, when measuring in different seasons or different sea areas, the difference in water temperature may cause the speed of sound to change. After calibration, the influence of this change on water depth measurement can be eliminated, making the measurement result more accurate and more truly reflecting the actual depth of the underwater terrain.

[0089] In the positioning module, the satellite positioning data is corrected using the differential information provided by the ground reference station, and the accelerometer and gyroscope errors of the inertial navigation system are calibrated by comparing with reference points with known precise positions and attitudes, which can effectively improve the positioning accuracy. The satellite positioning system can overcome the influence of factors such as atmospheric delay and satellite clock error through differential correction. The inertial navigation system can reduce the error accumulation of the sensor itself after calibration, thereby providing more accurate position and attitude information, which is very critical for accurately depicting the position and shape of underwater terrain.

[0090] The environmental monitoring module calibrates the sensor according to the measured values ​​under the standard solution or standard environment, which can ensure the measurement accuracy of environmental parameters (water temperature, water quality, water flow rate, etc.). For example, the water quality sensor may drift after a period of use. By calibrating it with a standard solution, its measured value can be adjusted to the accurate range, providing reliable data support for the evaluation of the underwater environment.

[0091] An underwater topography measurement method, comprising an underwater topography measurement system as described in any one of the above, comprising the following steps:

[0092] Step S1: Equipped with multiple high-precision acoustic sensors, combined with hybrid beam bathymetry technology, the corresponding water depth data is calculated;

[0093] Step S2: integrating a satellite positioning system and an inertial navigation system for positioning;

[0094] Step S3: using a water temperature sensor, a water quality sensor and a water flow velocity sensor to monitor the environment;

[0095] Step S4: Process and transmit in real time the large amount of data transmitted from the depth measurement module, the positioning module and the environment monitoring module.

[0096] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0097] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An underwater topographic measurement system, characterized in that: include: Depth measurement module, positioning module, environmental monitoring module and data processing and transmission module; The depth measurement module is equipped with multiple high-precision acoustic sensors and combines hybrid beam bathymetry technology to calculate the corresponding water depth data; The positioning module integrates satellite positioning system and inertial navigation system for positioning work; The environmental monitoring module includes a water temperature sensor, a water quality sensor and a water flow velocity sensor, which are used to monitor the environment; The data processing and transmission module is used to process and transmit the large amount of data sent by the depth measurement module, positioning module and environmental monitoring module in real time.

2. An underwater topographic measurement system according to claim 1, characterized in that: The operation process of the depth measurement module includes the following: The acoustic sensors are arranged in an array and are distributed at different angles and positions of the measuring equipment. Each sensor has an independent signal acquisition and preprocessing circuit, which is used to amplify and filter the weak electrical signals received by the acoustic sensor. Hybrid beam sounding technology includes wide beam transmission and narrow beam reception, and the transmission beam angle is set to 80 degrees.

3. An underwater topographic measurement system according to claim 2, characterized in that: The operation process of the depth measurement module also includes the following: When the wide beam transmits the acoustic signal, the sound wave propagates in the water and reflects back after hitting the bottom of the water. Multiple high-precision acoustic sensors receive the reflected echo signal and first time-stamp the signal to record the time interval t from the emission of the sound wave to the reception. Calculate the water depth using the formula: Among them, h is the water depth and v is the speed of sound waves in water.

4. An underwater topographic measurement system according to claim 3, characterized in that: The operation process of the positioning module includes the following: Using differential positioning technology, satellite signals are received at a base station with a known precise position, and the error difference between the satellite signals received by the measuring device is calculated. These error differences are transmitted to the satellite positioning system of the measuring device. The measuring device uses these error correction information to correct the position coordinates calculated by itself. The inertial measurement unit consists of an accelerometer and a gyroscope, and uses an inertial navigation algorithm to calculate the position based on the acceleration and angular velocity data provided.

5. An underwater topographic measurement system according to claim 4, characterized in that: The operation process of the positioning module also includes the following: The Kalman filter algorithm is used to fuse satellite positioning data and inertial navigation data, integrating the high-precision position information of the satellite positioning system and the high-frequency attitude and speed information of the inertial navigation system; During the fusion process, the weights of satellite positioning data and inertial navigation data are dynamically adjusted according to the signal quality of the satellite positioning system and the number of visible satellites.

6. An underwater topographic measurement system according to claim 5, characterized in that: The operation process of the environmental monitoring module includes the following: Water quality sensors include dissolved oxygen sensors, pH sensors and turbidity sensors.

7. An underwater topographic measurement system according to claim 6, characterized in that: The operation process of the data processing and transmission module includes the following: Equipped with multiple high-speed data interfaces, it can simultaneously receive data from the depth measurement module, positioning module and environmental monitoring module; Perform a preliminary integrity check on the received data, including packet header and packet tail check and data length verification; The data of each module is calibrated according to the calibration parameters pre-stored in the system. For the depth measurement module, the measurement error of the acoustic sensor is corrected using the data of a standard pool or calibration area with known depth, including sound velocity compensation; The satellite positioning data is corrected using the differential information provided by the ground reference station, and the accelerometer and gyroscope errors of the inertial navigation system are calibrated by comparing with reference points with known precise positions and attitudes; The environmental monitoring module calibrates the sensor based on the measured values ​​in standard solutions or standard environments.

8. An underwater topography measurement method, comprising an underwater topography measurement system according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1: Equipped with multiple high-precision acoustic sensors, combined with hybrid beam bathymetry technology, the corresponding water depth data is calculated; Step S2: integrating a satellite positioning system and an inertial navigation system for positioning; Step S3: using a water temperature sensor, a water quality sensor and a water flow velocity sensor to monitor the environment; Step S4: Process and transmit in real time the large amount of data transmitted from the depth measurement module, the positioning module and the environment monitoring module.

Images