Absolute sea level height measuring buoy and measuring method

Abstract

The application relates to an absolute sea surface height measuring buoy and a measuring method, which comprise a solar cell panel, a device cabin and at least three floating bodies, the floating bodies are connected with the device cabin through connecting rods, the top of the device cabin is provided with a GNSS antenna and a communication antenna, the inside of the device cabin is provided with a power supply, a GNSS receiver, a communication module, a processing unit and a solar controller, the outer wall of the device cabin is provided with a height detection mechanism, the floating body comprises a cylindrical float and a hemispherical floating ball arranged at the bottom of the float, and the solar cell panel is horizontally arranged on the top surface of the float; the outer diameter of the floating body is less than 1 / 4 of the wavelength of the measured sea surface wave. The application can realize real-time measurement of the height from the GNSS antenna to the measured sea surface, reduce the gravity center of the device cabin, reduce the inclination angle of the device cabin, improve the wave-following property of the buoy, and thus ensure the accuracy of the measurement.

Description

Technical Field

[0001] This invention belongs to the field of absolute sea surface elevation measurement technology, and in particular to an absolute sea surface elevation measurement buoy and measurement method. Background Technology

[0002] Absolute sea surface elevation measuring buoys primarily utilize GNSS satellite signals to measure absolute sea surface elevation. The principle is that a GNSS antenna mounted on the buoy receives satellite signals, and a GNSS receiver decodes the received signals to obtain coordinate and elevation information. The obtained elevation information is then subtracted from the distance from the GNSS antenna to the water surface to obtain the absolute sea surface elevation to be measured. The formula is as follows: h Sea =h GNSS -h Buoy In the above formula, h GNSS h represents the elevation of the buoy's GNSS antenna to standard sea level. Buoy The height h represents the distance from the buoy's GNSS antenna to the sea surface being measured. Sea This represents the absolute elevation of the sea surface to be measured from the standard sea level. From the formula, we can see that h... Sea The accuracy depends on h GNSS and h Buoy h GNSS It depends on the GNSS receiver's calculation results and is generally difficult to improve. Buoy Pre-measurement in the laboratory is required, and the laboratory measurement is used to calculate the actual value in practical applications. However, due to various factors, there is a significant error between the actual value and the laboratory measurement. Zhai Wanlin et al., in their paper "Absolute Sea Surface Elevation Measurement System, Measurement Method and Satellite Altimeter Calibration System" (Chinese Patent, Application No. CN202211036434), mentioned: 1. Part of the buoy's float and instrument compartment are submerged in water, and the temperature, salinity, and other parameters of the laboratory water differ significantly from the parameters of the seawater to be measured, requiring compensation. 2. When measuring in the laboratory, there is no influence from factors such as waves and currents, but in practical applications, the effects of mooring, waves, and currents must be considered. Therefore, the measurement accuracy of the absolute sea surface elevation buoy mainly depends on the distance from the GNSS antenna to the sea surface. Due to the influence of wind, waves, currents, and the difference between the measured sea area and the laboratory water, the actual distance from the GNSS antenna to the sea surface has a certain error compared to the laboratory measurement. If the distance from the GNSS antenna to the sea surface can be measured in real time, the accuracy and convenience of absolute sea surface elevation measurement buoys will be greatly improved.

[0003] Furthermore, traditional buoys are often designed in a spherical shape with a center of gravity close to the bottom to prevent capsizing in rough sea conditions. While this tumbler design provides excellent anti-capsulation performance, it suffers from poor wave-following ability; that is, the buoy tends to tilt when waves appear and cannot rise and fall vertically with the waves. CN111409774A discloses a GNSS buoy for measuring sea level. By incorporating multiple ultrasonic level gauges, the measurement results can be corrected, improving accuracy. However, this buoy also suffers from poor wave-following ability. If the tilt angle of the equipment compartment can be minimized, the measurement results will undoubtedly be more accurate. CN205098417U discloses a GNSS sea level geodetic height measuring buoy, including a triangular support, a buoy, a GNSS antenna, and an instrument compartment. The instrument compartment is located in the center of the triangular support, which connects to the buoy. The GNSS antenna is fixed to a sealed cover on the upper part of the instrument compartment, and an radome is installed on the GNSS antenna. This type of buoy has high wave-following ability, but because the electrical equipment requires continuous power, this buoy is powered only by a battery, resulting in poor endurance. To improve the endurance of buoys, solar panels are often installed on them to charge batteries, such as CN114872833A - a Beidou positioning wave measuring buoy. However, almost all current buoys place the solar panels on the top of the equipment compartment, requiring a support frame to install them. This increases the structural complexity of the equipment compartment. The weight of the solar panels and the support frame makes the center of gravity of the equipment compartment high, which is not conducive to maintaining stability and makes it easy to tilt under the influence of waves. Furthermore, during buoy deployment and retrieval, the support frame is prone to entanglement with the ropes, affecting the convenience of deployment and retrieval. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an absolute sea surface elevation measuring buoy and a measuring method that can measure the height of the GNSS antenna to the sea surface to be measured in real time, lower the center of gravity of the equipment cabin, reduce the tilt angle of the equipment cabin, and improve the wave-following property of the buoy, thereby ensuring the accuracy of the measurement.

[0005] To address the aforementioned problems, the present invention employs the following technical solution: an absolute sea surface elevation measuring buoy, comprising a solar panel, an equipment compartment, and at least three floats, wherein the floats are evenly distributed around the equipment compartment, and the floats are connected to the equipment compartment via connecting rods.

[0006] The top of the equipment compartment is equipped with a GNSS antenna and a communication antenna. Inside the equipment compartment are a power supply, a GNSS receiver, a communication module, a processing unit, and a solar controller. The outer wall of the equipment compartment is equipped with a height detection mechanism. The height detection mechanism, the GNSS receiver, and the communication module are all connected to the processing unit. The GNSS antenna is connected to the GNSS receiver, and the communication antenna is connected to the communication module. The solar panel, the solar controller, and the power supply are connected in sequence.

[0007] The float includes a cylindrical pontoon and a hemispherical buoy disposed at the bottom of the pontoon, and the solar panel is horizontally disposed on the top surface of the pontoon;

[0008] The outer diameter of the float is less than 1 / 4 wavelength of the ocean wave being measured.

[0009] Furthermore, the top of the equipment compartment is provided with a detachable cover, the GNSS antenna and communication antenna are disposed on the upper surface of the cover, and the equipment bracket is fixedly connected to the cover.

[0010] Furthermore, the power supply is located at the bottom of the equipment compartment, and an equipment bracket is located above the power supply. The solar controller is located at the bottom of the equipment bracket, and the GNSS receiver, communication module, and processing unit are all located within the equipment bracket above the solar controller.

[0011] Furthermore, a flange is provided on the top edge of the equipment compartment, and the compartment cover is connected to the flange by bolts, with a sealing ring provided between the compartment cover and the flange.

[0012] Furthermore, the hatch is equipped with multiple watertight connectors.

[0013] Furthermore, the height detection mechanism is an ultrasonic level gauge.

[0014] Furthermore, the float comprises a foam body and a polyurea reinforcing layer arranged sequentially from the inside out.

[0015] Furthermore, there are three floats, which are located at the three vertices of an equilateral triangle.

[0016] Furthermore, each float is pre-embedded with a stainless steel pipe that penetrates the float radially. The outer wall of the top of the equipment compartment is provided with three connecting lugs. There are three connecting rods, with the connecting lugs penetrating the middle of each connecting rod. One end of the connecting rod is connected to the stainless steel pipe, and the other end is connected to the adjacent connecting rod.

[0017] Furthermore, the outer diameter of the float is 1 to 2 m.

[0018] The absolute sea surface elevation measurement method uses the aforementioned absolute sea surface elevation measuring buoy. The altitude detection agency monitors the distance between itself and the sea surface being measured in real time and calculates the distance from the GNSS antenna to the antenna being measured. The GNSS receiver receives GNSS satellite signals in real time through the GNSS antenna and calculates the distance from the GNSS antenna to the standard sea surface. Finally, the absolute sea surface elevation of the sea surface being measured is calculated.

[0019] The beneficial effects of this invention are as follows: 1. This invention utilizes a GNSS antenna to receive GNSS satellite signals and transmits them to a GNSS receiver. The GNSS receiver can then calculate the distance from the GNSS antenna to the standard sea surface. Furthermore, an altitude detection mechanism is used to detect the distance from the mechanism itself to the sea surface being measured, thus calculating the distance from the GNSS antenna to the sea surface and consequently, the absolute sea surface elevation. This invention reduces errors caused by differences in buoy draft due to wind, waves, currents, and variations in water temperature and salinity by performing real-time measurements on the sea surface being measured. It also eliminates the need for pre-measurement and estimation of differences between laboratory water and the sea area being measured, significantly reducing workload and errors. Furthermore, since real-time measurements can be performed using instruments, manual estimation of factors such as wind, waves, and currents is no longer required, further reducing measurement errors.

[0020] 2. The entire buoy is flat, which provides better wave-following performance. In addition, the outer diameter of the buoy is less than 1 / 4 wavelength of the wave on the measured sea surface, and its small volume allows the buoy to rise and fall with the waves, further improving the buoy's wave-following performance, reducing the tilt angle of the equipment compartment, and thus improving the accuracy of the measurement.

[0021] 3. By installing solar panels, the buoy's endurance is improved. In addition, by integrating the solar panels with the buoy body, instead of placing the solar panels in the equipment compartment, the weight of the equipment compartment is reduced, which helps to lower the center of gravity of the equipment compartment. At the same time, there is no need to install a support frame, which simplifies the structure of the equipment compartment and facilitates the deployment and recovery of the buoy. Attached Figure Description

[0022] Figure 1 This is a perspective view of the present invention;

[0023] Figure 2 This is a schematic diagram of the equipment compartment;

[0024] Figure 3 This is an enlarged schematic diagram of the equipment compartment;

[0025] Figure 4 This is a schematic diagram of a floating body;

[0026] Reference numerals: 1—Equipment compartment; 101—Flange; 102—Connecting lug; 103—Hatch cover; 104—Watertight connector; 2—GNSS antenna; 3—Communication antenna; 4—Connecting rod; 5—Float; 501—Stainless steel pipe; 502—Solar panel; 6—Altitude detection mechanism; 7—GNSS receiver; 8—Communication module; 9—Processing unit; 10—Power supply; 11—Solar controller; 12—Equipment support. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] The absolute sea surface elevation measuring buoy of the present invention, such as Figures 1 to 4 As shown, it includes a solar panel 502, an equipment compartment 1, and at least three floats 5. The floats 5 are evenly distributed around the equipment compartment 1, and the floats 5 are connected to the equipment compartment 1 by connecting rods 4.

[0029] The float 5 provides buoyancy for the entire buoy and is made of a low-density, lightweight material, such as foam. Since seawater is highly corrosive, a layer of polyurea material can be coated on the outer wall of the float 5 to provide corrosion protection. Therefore, the float 5 of this invention comprises a foam body and a polyurea reinforcing layer arranged sequentially from the inside out.

[0030] The equipment compartment 1, as the main measuring component, is equipped with a GNSS antenna 2 and a communication antenna 3 on its top. Inside the equipment compartment 1 are a power supply 10, a GNSS receiver 7, a communication module 8, a processing unit 9, and a solar controller 11. The outer wall of the equipment compartment 1 is equipped with a height detection mechanism 6. The height detection mechanism 6, the GNSS receiver 7, and the communication module 8 are all connected to the processing unit 9. The GNSS antenna 2 is connected to the GNSS receiver 7, and the communication antenna 3 is connected to the communication module 8. The solar panel 502, the solar controller 11, and the power supply 10 are connected in sequence.

[0031] GNSS antenna 2 is used to receive GNSS satellite signals, and communication antenna 3 is used to transmit and receive communication signals. Power supply 10 uses a common storage battery to power various electrical components. GNSS receiver 7 is used to calculate GNSS satellite signals, determine the distance from GNSS antenna 2 to the standard sea surface, and transmit the calculated data to processing unit 9. Communication module 8 is used for communication, specifically RS485 communication, which can remotely transmit measurement data to the ground station. Altitude detection mechanism 6 is used to detect the distance from itself to the measured sea surface. In this invention, the lower part of equipment compartment 1 is below the water surface, and the upper part is above the water surface. Therefore, altitude detection mechanism 6 can be placed in the upper part of equipment compartment 1, so that altitude detection mechanism 6 is above the sea surface, and the distance from altitude detection mechanism 6 to the sea surface can be detected; alternatively, altitude detection mechanism 6 can be placed in the lower part of equipment compartment 1, so that altitude detection mechanism 6 is below the sea surface. In this case, an ultrasonic level gauge can be used, with the probe of the ultrasonic level gauge pointing upwards towards the water surface, with an accuracy of 1 mm, to detect the liquid level at the location of altitude detection mechanism 6. Processing unit 9 is used to calculate the absolute sea surface elevation and control signal transmission and reception. Processing unit 9 has a built-in calculation program. Based on the distance from the height detection mechanism 6 to the measured sea surface and the height difference between the height detection mechanism 6 and the GNSS antenna 2, it can calculate the distance from the GNSS antenna 2 to the measured sea surface. Then, based on the distance from the GNSS antenna 2 to the standard sea surface calculated by the GNSS receiver 7, the absolute sea surface elevation can be calculated. The calculation process is simple, and a conventional processing chip can complete the calculation task. Solar controller 11 is used to control solar charging and discharging; a conventional solar charging and discharging controller is sufficient.

[0032] The float 5 specifically includes a cylindrical buoy and a hemispherical buoy located at the bottom of the buoy. A solar panel 502 is horizontally mounted on the top surface of the buoy. The solar panel 502 can be fixed to the upper surface of the float 5 using polyurea. Since the solar panel 502 is relatively heavy, mounting it on the float 5 eliminates the need for a separate solar panel on the equipment compartment 1. This lowers the center of gravity of the equipment compartment 1, improving its stability. When waves occur on the sea surface being measured, the tilt angle of the equipment compartment 1 is smaller, minimizing the impact on detection accuracy. Furthermore, eliminating the need for a support structure on the equipment compartment 1 simplifies its structure, reduces exposed components, and reduces the likelihood of rope entanglement during deployment and retrieval. Additionally, since there are at least three floats 5, and each float 5 has a solar panel 502 mounted on its upper surface, the total area of ​​the solar panels 502 is larger, resulting in higher power generation and improved endurance.

[0033] The outer diameter of the float 5 is less than 1 / 4 wavelength of the wave on the sea surface being measured. Specifically, the outer diameter of the float 5 is 1 to 2 m. When the outer diameter of the float 5 is less than 1 / 4 wavelength of the wave, the float 5 occupies a smaller area and can rise and fall with the waves, thus having better wave-following ability.

[0034] Components such as the power supply 10, GNSS receiver 7, communication module 8, processing unit 9, and solar controller 11 are housed inside the equipment compartment 1 to prevent corrosion or damage from seawater. To facilitate maintenance of the components within the equipment compartment 1, a removable cover 103 is provided on the top of the equipment compartment 1. Specifically, the main body of the equipment compartment 1 is a stainless steel or titanium alloy cylindrical container with a sealed bottom. A flange 101 is provided on the top edge of the equipment compartment 1, and the cover 103 is bolted to the flange 101. A sealing ring is provided between the cover 103 and the flange 101 to improve sealing and prevent seawater from entering the equipment compartment 1 through the gap between the cover 103 and the flange 101. The GNSS antenna 2 and the communication antenna 3 are located on the upper surface of the cover 103. Multiple watertight connectors 104 are installed on the hatch 103. The GNSS antenna 2, communication antenna 3 and altitude detection mechanism 6 are connected to the internal GNSS receiver 7, communication module 8 and processing unit 9 through the watertight connectors 104 to prevent seawater from entering the equipment compartment 1.

[0035] The power supply 10 is located at the bottom of the equipment compartment 1, and an equipment bracket 12 is mounted above it. The equipment bracket 12 is fixedly connected to the cover 103. The solar controller 11 is located at the bottom of the equipment bracket 12, and the GNSS receiver 7, communication module 8, and processing unit 9 are all located within the equipment bracket 12 above the solar controller 11. Since batteries are generally quite heavy, placing the power supply 10 at the bottom of the equipment compartment 1 and placing other lighter components at the top further lowers the center of gravity of the equipment compartment 1. The equipment bracket 12 is fixed to the cover 103, and components such as the GNSS receiver 7, communication module 8, processing unit 9, and solar controller 11 are mounted on the equipment bracket 12. During maintenance, the cover 103 can be removed to take out the equipment bracket 12, GNSS receiver 7, communication module 8, processing unit 9, and solar controller 11 as a whole for easy inspection and maintenance of each component.

[0036] The floats 5 can be four, five, or more, located at the vertices of a regular polygon and evenly distributed around the equipment compartment 1 to ensure the stability of the entire buoy. In a preferred embodiment, there are three floats 5, located at the three vertices of an equilateral triangle.

[0037] To achieve a stable connection between the float 5 and the equipment compartment 1, a stainless steel pipe 501 is pre-embedded within each float 5, penetrating radially through the float 5. Three connecting lugs 102 are provided on the outer wall of the top of the equipment compartment 1, each lug having a through hole. Three connecting rods 4 are provided, each with its middle section passing through a connecting lug 102. One end of each connecting rod 4 is connected to the stainless steel pipe 501, and the other end is connected to the adjacent connecting rod 4. Specifically, a connecting sleeve can be provided at one end of each connecting rod 4, with a 60-degree angle between the sleeve and the rod. One end of the sleeve extends into the stainless steel pipe 501 and is connected to it with a screw. The other end of the sleeve is fitted over the end of the adjacent connecting rod 4 and connected to it with a screw. The three connecting rods 4 form a triangular support, providing strong stability. The connecting lugs 102 can be welded to the outer wall of the equipment compartment 1 or hinged to it via a universal joint, allowing the lugs 102 to rotate in any direction. When waves appear on the sea surface, the waves will generally reach a float 5 first. The float 5 rises and falls with the waves. Since the connecting lug 102 can rotate, the rise and fall of the float 5 will drive the connecting rod 4 connected to the float 5 to rotate. The connecting rod 4 will rotate to an inclined state, while the equipment compartment 1 will not be affected by the rise and fall of the float 5 and can remain in a vertical state without tilting. That is, the force generated by the rise and fall of the float 5 is transmitted to other floats 5 through the connecting rod 4, with little impact on the equipment compartment 1 and will not cause the equipment compartment 1 to tilt, thus ensuring the accuracy of the detection.

[0038] The absolute sea surface elevation measurement method of the present invention uses the above-mentioned absolute sea surface elevation measuring buoy. The height detection mechanism 6 monitors the distance between itself and the sea surface being measured in real time and calculates the distance from the GNSS antenna 2 to the antenna being measured. The GNSS receiver 7 receives GNSS satellite signals in real time through the GNSS antenna 2 and calculates the distance from the GNSS antenna 2 to the standard sea surface. Finally, the absolute sea surface elevation of the sea surface being measured is calculated.

[0039] This invention reduces errors caused by variations in buoy draft due to real-time measurements of the sea surface being measured, thereby correcting the results in real time. This is achieved by measuring the buoy's draft in real time, reducing errors caused by differences in buoy draft due to variations in water quality such as wind, waves, currents, and temperature / salinity. It also eliminates the need for pre-experimental measurements and the estimation of differences between laboratory and target water conditions, significantly reducing workload and errors. Furthermore, since real-time measurements can be performed using instruments, manual estimation of factors such as wind, waves, and currents is no longer required, further reducing measurement errors.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An absolute sea surface elevation measuring buoy, comprising a solar panel (502), an equipment compartment (1), and at least three floats (5), the floats (5) being evenly distributed around the equipment compartment (1), and the floats (5) being connected to the equipment compartment (1) via connecting rods (4), characterized in that: The top of the equipment compartment (1) is equipped with a GNSS antenna (2) and a communication antenna (3). Inside the equipment compartment (1) are a power supply (10), a GNSS receiver (7), a communication module (8), a processing unit (9), and a solar controller (11). The outer wall of the equipment compartment (1) is equipped with a height detection mechanism (6). The height detection mechanism (6), the GNSS receiver (7), and the communication module (8) are all connected to the processing unit (9). The GNSS antenna (2) is connected to the GNSS receiver (7). The communication antenna (3) is connected to the communication module (8). The solar panel (502), the solar controller (11), and the power supply (10) are connected in sequence. The float (5) includes a cylindrical pontoon and a hemispherical buoy disposed at the bottom of the pontoon, and the solar panel (502) is horizontally disposed on the top surface of the pontoon; The outer diameter of the float (5) is less than 1 / 4 wavelength of the sea wave being measured. There are three floats (5), and the three floats (5) are located at the three vertices of an equilateral triangle; Each float (5) is pre-embedded with a stainless steel pipe (501), which penetrates the float (5) radially. The outer wall of the top of the equipment compartment (1) is provided with three connecting lugs (102). There are three connecting rods (4), and the middle of each connecting rod (4) penetrates the connecting lug (102). One end of the connecting rod (4) is connected to the stainless steel pipe (501), and the other end is connected to the adjacent connecting rod (4). The connecting lug (102) is hinged to the outer wall of the equipment compartment (1) via a universal connecting ball, so that the connecting lug (102) can rotate in any direction.

2. The absolute sea surface elevation measuring buoy as described in claim 1, characterized in that: The equipment compartment (1) is provided with a removable cover (103) on top, and the GNSS antenna (2) and communication antenna (3) are provided on the upper surface of the cover (103).

3. The absolute sea surface elevation measuring buoy as described in claim 2, characterized in that: The power supply (10) is located at the bottom of the equipment compartment (1), and an equipment bracket (12) is located above the power supply (10). The equipment bracket (12) is fixedly connected to the cover (103). The solar controller (11) is located at the bottom of the equipment bracket (12). The GNSS receiver (7) and the communication module (8) are located inside the equipment bracket (12) above the solar controller (11) along with the processing unit (9).

4. The absolute sea surface elevation measuring buoy as described in claim 2, characterized in that: The top edge of the equipment compartment (1) is provided with a flange (101). The cover (103) is connected to the flange (101) by bolts, and a sealing ring is provided between the cover (103) and the flange (101).

5. The absolute sea surface elevation measuring buoy as described in claim 2, characterized in that: The hatch (103) is provided with multiple watertight connectors (104).

6. The absolute sea surface elevation measuring buoy as described in claim 1, characterized in that: The height detection mechanism (6) is an ultrasonic level gauge.

7. The absolute sea surface elevation measuring buoy as described in claim 1, characterized in that: The float (5) comprises a foam body and a polyurea reinforcement layer arranged sequentially from the inside out.

8. A method for measuring absolute sea surface elevation, characterized in that: Using the absolute sea surface elevation measuring buoy as described in any one of claims 1 to 7, the elevation detection mechanism (6) monitors the distance between itself and the sea surface being measured in real time and calculates the distance from the GNSS antenna (2) to the antenna being measured; the GNSS receiver (7) receives GNSS satellite signals in real time through the GNSS antenna (2) and calculates the distance from the GNSS antenna (2) to the standard sea surface, and finally calculates the absolute sea surface elevation of the sea surface being measured.

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