A method and system for measuring wave height in a complex sea area based on PPP-B2b and ADCP

Abstract

The application discloses a complex sea area wave height measuring method and system based on PPP-B2b and ADCP, and comprises the following steps: obtaining PPP-B2b correction information by using GNSS, combining the correction information with broadcast ephemeris, generating precise orbit and clock error, and obtaining corrected positioning information; collecting flow velocity collected by an ADCP sensor and inertial data collected by an inertial measurement unit in real time, and obtaining preliminary position information by processing; performing weighted fusion on the preliminary position information and the corrected positioning information, obtaining fused real-time position and motion velocity, performing vertical motion velocity integration according to the real-time position and the motion velocity, obtaining vertical displacement change information with time, and then extracting real-time wave height by using a cross-zero method and a spectrum analysis method. The wave height measured by the application has higher precision.

Description

Technical Field

[0001] This invention relates to wave height measurement technology, and more particularly to a method and system for wave height measurement in complex sea areas based on PPP-B2b and ADCP. Background Technology

[0002] Precise Point Positioning (PPP) is a high-precision positioning method that uses carrier phase and ranging code pseudorange observations received by a single GNSS (Global Navigation Satellite System) receiver. This method requires access to precise products released by organizations such as the International GNSS Service (IGS) via a communication network to correct for errors such as satellite orbit and clock bias. However, relying on communication networks to obtain precise orbit and clock bias information has certain limitations.

[0003] To address this issue, this method utilizes B2b signals broadcast by three GEO (Geosynchronous Earth Orbit) satellites to provide precise point positioning services. The precise orbit and clock bias information carried by the PPP-B2b signals allows users to obtain high-precision positioning results without overly relying on communication networks and reference stations.

[0004] In complex sea areas, due to harsh conditions, traditional wave height measurement methods are unusable. Therefore, there is an urgent need to research a wave height measurement technique for complex sea areas. Existing technologies include methods that calculate wave height using GNSS data, but the accuracy of these methods needs further improvement. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this invention is to provide a method and system for measuring wave height in complex sea areas based on PPP-B2b and ADCP, which improves the accuracy of wave measurement.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A method for measuring wave height in complex sea areas based on PPP-B2b and ADCP includes the following steps:

[0008] (1) The received pseudorange and carrier observations are read by a GNSS receiver, the PPP-B2b correction information is obtained by parsing, and the information is merged with the broadcast ephemeris to generate a precise orbit and clock error, and the corrected positioning information is obtained.

[0009] (2) Real-time acquisition of flow velocity data collected by ADCP sensor and inertial data collected by inertial measurement unit, and processing to obtain preliminary position information;

[0010] (3) The preliminary location information and the corrected location information are weighted and fused to obtain the fused real-time location and motion speed. The weighting factor during fusion is corrected in real time through the error model.

[0011] (4) Based on the real-time position and velocity, the vertical velocity is integrated to obtain the information on the change of vertical displacement over time, and then the real-time wave height is extracted using the zero-crossing method and spectral analysis.

[0012] (5) Real-time storage of wave height, and use wireless communication to back up the stored data to a remote server.

[0013] Furthermore, step (1) specifically includes:

[0014] (1.1) Use the GNSS receiver on the equipment to read the received pseudorange and carrier observations;

[0015] (1.2) By receiving the PPP-B2b signal, the B2B message is obtained, the message is decoded and the correction number is matched to obtain the PPP-B2b correction information;

[0016] (1.3) The received broadcast ephemeris and the parsed PPP-B2b correction information are merged to generate a precise orbit and clock bias;

[0017] (1.4) Based on the precision track and clock difference, perform PPP positioning to obtain the corrected positioning information.

[0018] Furthermore, step (2) specifically includes:

[0019] (2.1) Real-time acquisition of flow velocity data collected by ADCP sensor and inertial data collected by inertial measurement unit;

[0020] (2.2) The collected inertial data is preprocessed. The inertial navigation system algorithm is used to process the inertial data and flow velocity to obtain preliminary position information.

[0021] Furthermore, step (3) specifically includes:

[0022] (3.1) The position information in the preliminary position information and the corrected position information are weighted and fused to obtain the fused real-time position, and the real-time motion speed is calculated based on the fused real-time position;

[0023] (3.2) Calculate the difference between the preliminary location information and the fused real-time location, and adjust the weight factor of the preliminary location information according to the difference, which will be used as the weight factor for the next fusion.

[0024] (3.3) The difference between the location information in the corrected location information and the real-time location after fusion is calculated, and the weight factor of the location information in the corrected location information is adjusted according to the difference, and used as the weight factor for the next fusion.

[0025] Furthermore, step (4) specifically includes:

[0026] (4.1) After obtaining the fused real-time position and motion velocity, the vertical motion velocity is integrated within a sliding time window to obtain the information on the change of vertical displacement over time;

[0027] (4.2) Remove systematic errors and tidal effects from the information on vertical displacement over time;

[0028] (4.3) Real-time wave height is extracted from the processed vertical displacement data using the zero-crossing method and spectral analysis.

[0029] A wave height measurement system for complex sea areas based on PPP-B2b and ADCP includes:

[0030] The PPP positioning module is used to read the received pseudorange and carrier observations using a GNSS receiver, analyze them to obtain PPP-B2b correction information, and merge them with broadcast ephemeris to generate precise orbit and clock bias, thus obtaining the corrected positioning information.

[0031] The acquisition module is used to acquire the flow velocity collected by the ADCP sensor and the inertial data collected by the inertial measurement unit in real time, and process them to obtain preliminary position information.

[0032] The information fusion module is used to perform weighted fusion of the preliminary location information and the corrected location information to obtain the fused real-time location and motion velocity. The weighting factors during fusion are corrected in real time through an error model.

[0033] The wave height calculation module is used to perform vertical velocity integration based on real-time position and velocity to obtain information on vertical displacement over time, and then use the zero-crossing method and spectral analysis to extract real-time wave height.

[0034] The storage and transmission module is used to store wave height in real time and back up the stored data to a remote server using wireless communication.

[0035] Furthermore, the PPP positioning module is specifically used to perform the following steps:

[0036] Use the GNSS receiver on the equipment to read the received pseudorange and carrier observations;

[0037] By receiving PPP-B2b signals, obtaining B2B messages, decoding messages and matching correction numbers, PPP-B2b correction information can be obtained.

[0038] The received broadcast ephemeris and the parsed PPP-B2b correction information are combined to generate a precise orbit and clock bias;

[0039] Based on the precise track and clock error, PPP positioning is performed to obtain the corrected positioning information.

[0040] Furthermore, the acquisition module is used to perform the following steps:

[0041] Real-time acquisition of flow velocity data collected by ADCP sensor and inertial data collected by inertial measurement unit;

[0042] The collected inertial data is preprocessed, and inertial navigation system algorithms are used to process the inertial data and flow velocity to obtain preliminary position information.

[0043] Furthermore, the information fusion module is specifically used to perform the following steps:

[0044] The initial location information and the corrected location information are weighted and fused to obtain the fused real-time location, and the real-time motion speed is calculated based on the fused real-time location.

[0045] The difference between the preliminary location information and the fused real-time location is calculated, and the weight factor of the preliminary location information is adjusted based on the difference, which is then used as the weight factor for the next fusion.

[0046] The difference between the location information in the corrected location information and the fused real-time location is calculated, and the weighting factor of the location information in the corrected location information is adjusted based on the difference, which is then used as the weighting factor for the next fusion.

[0047] Furthermore, the wave height calculation module is specifically used to perform the following steps:

[0048] After obtaining the fused real-time position and velocity, the vertical displacement over time is obtained by integrating the vertical velocity within a sliding time window.

[0049] Remove systematic errors and tidal effects from the information on vertical displacement over time;

[0050] Real-time wave height is extracted from the processed vertical displacement data using the zero-crossing method and spectral analysis.

[0051] Compared with the prior art, the beneficial effects of this invention are:

[0052] 1. Integration of PPP-B2b and ADCP: Traditional GNSS wave height measurement relies solely on the receiver's vertical displacement to calculate wave height, but this is easily affected by sea surface multipath effects, ocean currents, and environmental noise. This invention combines current velocity information from ADCP (Acoustic Doppler Current Meter) with PPP-B2b positioning data for joint calculation. This significantly improves the system's continuity, dynamic response capability, and error correction capability.

[0053] 2. A novel multi-source fusion process for wave height extraction: Utilizing vertical velocity integration → removing tidal / systematic errors → zero-crossing method + spectral analysis to extract real-time wave height, which is more robust than single GNSS vertical displacement estimation. Especially in complex sea areas (strong currents, multipath reflections), the fusion with ADCP effectively filters environmental interference, improving real-time performance and accuracy. Attached Figure Description

[0054] Figure 1 This is a flowchart illustrating the wave height measurement method for complex sea areas based on PPP-B2b and ADCP provided in an embodiment of the present invention.

[0055] Figure 2 This is the ADCP data processing flow provided in the embodiments of the present invention. Detailed Implementation

[0056] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0057] Example 1

[0058] A wave height measurement method for complex sea areas based on PPP-B2b and ADCP, such as Figure 1 As shown, it includes the following steps:

[0059] (1) The received pseudorange and carrier observations are read by a GNSS receiver, the PPP-B2b correction information is obtained by parsing, and the information is merged with the broadcast ephemeris to generate a precise orbit and clock error, and the corrected positioning information is obtained.

[0060] Step (1) specifically includes:

[0061] (1.1) Use the GNSS receiver on the equipment to read the received pseudorange and carrier observations;

[0062] (1.2) By receiving the PPP-B2b signal, the B2B message is obtained, the message is decoded and the correction number is matched to obtain the PPP-B2b correction information;

[0063] (1.3) The received broadcast ephemeris and the parsed PPP-B2b correction information are merged to generate a precise orbit and clock bias;

[0064] (1.4) Based on the precision track and clock difference, perform PPP positioning to obtain the corrected positioning information.

[0065] Specifically, based on the received pseudorange and carrier observations, the observation equations are listed as follows:

[0066] )

[0067] In the formula, r, S, and j represent the receiver, satellite, and frequency, respectively;

[0068] These are the original carrier phase observations;

[0069] Geometric distance;

[0070] c is the speed of light;

[0071] and These are the clock biases for the satellite and receiver, respectively.

[0072] This is a wetted projection function related to satellite elevation angle obtained through the Global Mapping Function (GMF);

[0073] It is the zenith wet delay of station r;

[0074] Frequency The oblique ionospheric delay;

[0075] Frequency-dependent ionospheric delay amplification factor ;

[0076] and These are the uncalibrated pseudorange hardware delays (UCD) at the satellite and receiver ends, respectively.

[0077] and These are the uncalibrated phase delay (UCD) at the receiver and satellite ends, respectively.

[0078] and These are pseudorange and carrier phase measurement noise, respectively.

[0079] Correct all errors and use Kalman filtering for parameter estimation.

[0080] (2) The flow velocity collected by the ADCP sensor and the inertial data collected by the inertial measurement unit are collected in real time and processed to obtain preliminary position information.

[0081] Step (2) specifically includes:

[0082] (2.1) Real-time acquisition of flow velocity data collected by ADCP sensor and inertial data (acceleration and angular velocity data) collected by inertial measurement unit (IMU) as the motion state of buoy;

[0083] (2.2) The collected inertial data is preprocessed using inertial navigation system algorithms to process the flow velocity and inertial data, obtaining preliminary position information: such as Figure 2 As shown, the inertial navigation error equation can be expressed as:

[0084]

[0085]

[0086] The actual value of the location

[0087] The true value of speed

[0088] Location estimate

[0089] : Estimated speed.

[0090] (3) The preliminary location information and the corrected location information are weighted and fused to obtain the fused real-time location and motion speed. The weighting factor during fusion is corrected in real time through the error model.

[0091] Step (3) specifically includes:

[0092] (3.1) The position information in the preliminary position information and the corrected position information are weighted and fused to obtain the fused real-time position, and the real-time motion speed is calculated based on the fused real-time position;

[0093] (3.2) Calculate the difference between the preliminary location information and the fused real-time location, and adjust the weight factor of the preliminary location information according to the difference, which will be used as the weight factor for the next fusion; for example, set the weight factor to the ratio of the difference to the fused real-time location.

[0094] (3.3) Calculate the difference between the location information in the corrected positioning information and the fused real-time location, and adjust the weight factor of the location information in the corrected positioning information according to the difference, which will be used as the weight factor for the next fusion. For example, set the weight factor to the ratio of the difference to the fused real-time location.

[0095] (4) Based on the real-time position and velocity, the vertical velocity is integrated to obtain the information on the change of vertical displacement over time, and then the real-time wave height is extracted using the zero-crossing method and spectral analysis.

[0096] Step (4) specifically includes:

[0097] (4.1) After obtaining the fused real-time position and motion velocity, the vertical motion velocity is integrated within a sliding time window to obtain the information on the change of vertical displacement over time;

[0098] (4.2) Remove systematic errors and tidal effects from the information on vertical displacement over time;

[0099] (4.3) Real-time wave height is extracted from the processed vertical displacement data using the zero-crossing method and spectral analysis.

[0100] The real-time wave height formula algorithm is expressed as follows:

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] f: frequency;

[0107] S(f): Power spectral density;

[0108] : nth order spectral moment;

[0109] : Real-time wave height;

[0110] Average period;

[0111] One-tenth of the maximum wave height;

[0112] One-tenth of the maximum wave cycle.

[0113] (5) Real-time storage of wave height, and use wireless communication to back up the stored data to a remote server.

[0114] A high-capacity data storage device is installed on the buoy to store the PPP-B2b corrected positioning data and INS data in real time. The wave information obtained by this method can be stored locally on the buoy. The stored data is periodically backed up to a remote server using a wireless communication module to ensure data security.

[0115] Example 2

[0116] This invention provides a wave height measurement system for complex sea areas based on PPP-B2b and ADCP, comprising:

[0117] The PPP positioning module is used to read the received pseudorange and carrier observations using a GNSS receiver, analyze them to obtain PPP-B2b correction information, and merge them with broadcast ephemeris to generate precise orbit and clock bias, thus obtaining the corrected positioning information.

[0118] The acquisition module is used to acquire the flow velocity collected by the ADCP sensor and the inertial data collected by the inertial measurement unit in real time, and process them to obtain preliminary position information.

[0119] The information fusion module is used to perform weighted fusion of the preliminary location information and the corrected location information to obtain the fused real-time location and motion velocity. The weighting factors during fusion are corrected in real time through an error model.

[0120] The wave height calculation module is used to perform vertical velocity integration based on real-time position and velocity to obtain information on vertical displacement over time, and then use the zero-crossing method and spectral analysis to extract real-time wave height.

[0121] The storage and transmission module is used to store wave height in real time and back up the stored data to a remote server using wireless communication.

[0122] The PPP positioning module is specifically used to perform the following steps:

[0123] Use the GNSS receiver on the equipment to read the received pseudorange and carrier observations;

[0124] By receiving PPP-B2b signals, obtaining B2B messages, decoding messages and matching correction numbers, PPP-B2b correction information can be obtained.

[0125] The received broadcast ephemeris and the parsed PPP-B2b correction information are combined to generate a precise orbit and clock bias;

[0126] Based on the precise track and clock error, PPP positioning is performed to obtain the corrected positioning information.

[0127] The acquisition module is used to perform the following steps:

[0128] Real-time acquisition of flow velocity data collected by ADCP sensor and inertial data collected by inertial measurement unit;

[0129] The collected inertial data is preprocessed, and inertial navigation system algorithms are used to process the inertial data and flow velocity to obtain preliminary position information.

[0130] The information fusion module is specifically used to perform the following steps:

[0131] The position information in the preliminary position information and the corrected position information are weighted and fused to obtain the fused real-time position, and the real-time motion speed is calculated based on the fused real-time position;

[0132] The difference between the preliminary location information and the fused real-time location is calculated, and the weight factor of the preliminary location information is adjusted based on the difference, which is then used as the weight factor for the next fusion.

[0133] The difference between the location information in the corrected location information and the fused real-time location is calculated, and the weighting factor of the location information in the corrected location information is adjusted based on the difference, which is then used as the weighting factor for the next fusion.

[0134] The wave height calculation module is specifically used to perform the following steps:

[0135] After obtaining the fused real-time position and velocity, the vertical displacement over time is obtained by integrating the vertical velocity within a sliding time window.

[0136] Remove systematic errors and tidal effects from the information on vertical displacement over time;

[0137] Real-time wave height is extracted from the processed vertical displacement data using the zero-crossing method and spectral analysis.

[0138] The system provided in this embodiment of the invention can be used to execute the method provided in Embodiment 1 of the invention, and has the corresponding functions and beneficial effects of executing the method.

[0139] It is worth noting that in the embodiments of the above system, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy distinction between each other and are not used to limit the scope of protection of the present invention.

[0140] The embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art will clearly understand that each implementation can be achieved using software plus necessary general-purpose hardware platforms, or it can be implemented solely through hardware, as long as the function or purpose can be achieved.

[0141] It should be understood that the embodiments and descriptions above are only the principles, main features and advantages of the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope of the invention, and all such changes and modifications fall within the protection scope of the present invention.

Claims

1. A wave height measurement method for complex sea areas based on PPP-B2b and ADCP, characterized in that, Includes the following steps: (1) The received pseudorange and carrier observations are read by a GNSS receiver, the PPP-B2b correction information is obtained by parsing, and the information is merged with the broadcast ephemeris to generate a precise orbit and clock error, and the corrected positioning information is obtained. (2) Real-time acquisition of flow velocity data collected by ADCP sensor and inertial data collected by inertial measurement unit, and processing to obtain preliminary position information; (3) The preliminary location information and the corrected location information are weighted and fused to obtain the fused real-time location and motion speed. The weighting factor during fusion is corrected in real time through the error model. (4) Based on the real-time position and velocity, the vertical velocity is integrated to obtain the information on the change of vertical displacement over time, and then the real-time wave height is extracted using the zero-crossing method and spectral analysis. (5) Real-time storage of wave height, and use wireless communication to back up the stored data to a remote server.

2. The wave height measurement method for complex sea areas based on PPP-B2b and ADCP according to claim 1, characterized in that, Step (1) specifically includes: (1.1) Use the GNSS receiver on the equipment to read the received pseudorange and carrier observations; (1.2) By receiving the PPP-B2b signal, the B2B message is obtained, the message is decoded and the correction number is matched to obtain the PPP-B2b correction information; (1.3) The received broadcast ephemeris and the parsed PPP-B2b correction information are merged to generate a precise orbit and clock bias; (1.4) Based on the precision track and clock difference, perform PPP positioning to obtain the corrected positioning information.

3. The wave height measurement method for complex sea areas based on PPP-B2b and ADCP according to claim 1, characterized in that, Step (2) specifically includes: (2.1) Real-time acquisition of flow velocity data collected by ADCP sensor and inertial data collected by inertial measurement unit; (2.2) The collected inertial data is preprocessed. The inertial navigation system algorithm is used to process the inertial data and flow velocity to obtain preliminary position information.

4. The wave height measurement method for complex sea areas based on PPP-B2b and ADCP according to claim 1, characterized in that, Step (3) specifically includes: (3.1) The position information in the preliminary position information and the corrected position information are weighted and fused to obtain the fused real-time position, and the real-time motion speed is calculated based on the fused real-time position; (3.2) Calculate the difference between the preliminary location information and the fused real-time location, and adjust the weight factor of the preliminary location information according to the difference, which will be used as the weight factor for the next fusion. (3.3) The difference between the location information in the corrected location information and the real-time location after fusion is calculated, and the weight factor of the location information in the corrected location information is adjusted according to the difference, and used as the weight factor for the next fusion.

5. The wave height measurement method for complex sea areas based on PPP-B2b and ADCP according to claim 1, characterized in that, Step (4) specifically includes: (4.1) After obtaining the fused real-time position and motion velocity, the vertical motion velocity is integrated within a sliding time window to obtain the information on the change of vertical displacement over time; (4.2) Remove systematic errors and tidal effects from the information on vertical displacement over time; (4.3) Real-time wave height is extracted from the processed vertical displacement data using the zero-crossing method and spectral analysis.

6. A wave height measurement system for complex sea areas based on PPP-B2b and ADCP, characterized in that, include: The PPP positioning module is used to read the received pseudorange and carrier observations using a GNSS receiver, analyze them to obtain PPP-B2b correction information, and merge them with broadcast ephemeris to generate precise orbit and clock bias, thus obtaining the corrected positioning information. The acquisition module is used to acquire the flow velocity collected by the ADCP sensor and the inertial data collected by the inertial measurement unit in real time, and process them to obtain preliminary position information. The information fusion module is used to perform weighted fusion of the preliminary location information and the corrected location information to obtain the fused real-time location and motion velocity. The weighting factors during fusion are corrected in real time through an error model. The wave height calculation module is used to perform vertical velocity integration based on real-time position and velocity to obtain information on vertical displacement over time, and then use the zero-crossing method and spectral analysis to extract real-time wave height. The storage and transmission module is used to store wave height in real time and back up the stored data to a remote server using wireless communication.

7. The wave height measurement method for complex sea areas based on PPP-B2b and ADCP according to claim 6, characterized in that, The PPP positioning module is specifically used to perform the following steps: Use the GNSS receiver on the equipment to read the received pseudorange and carrier observations; By receiving PPP-B2b signals, obtaining B2B messages, decoding messages and matching correction numbers, PPP-B2b correction information can be obtained. The received broadcast ephemeris and the parsed PPP-B2b correction information are combined to generate a precise orbit and clock bias; Based on the precise track and clock error, PPP positioning is performed to obtain the corrected positioning information.

8. The wave height measurement method for complex sea areas based on PPP-B2b and ADCP according to claim 6, characterized in that, The acquisition module is used to perform the following steps: Real-time acquisition of flow velocity data collected by ADCP sensor and inertial data collected by inertial measurement unit; The collected inertial data is preprocessed, and inertial navigation system algorithms are used to process the inertial data and flow velocity to obtain preliminary position information.

9. The wave height measurement method for complex sea areas based on PPP-B2b and ADCP according to claim 6, characterized in that, The information fusion module is specifically used to perform the following steps: The initial location information and the corrected location information are weighted and fused to obtain the fused real-time location, and the real-time motion speed is calculated based on the fused real-time location. The difference between the preliminary location information and the fused real-time location is calculated, and the weight factor of the preliminary location information is adjusted based on the difference, which is then used as the weight factor for the next fusion. The difference between the location information in the corrected location information and the fused real-time location is calculated, and the weighting factor of the location information in the corrected location information is adjusted based on the difference, which is then used as the weighting factor for the next fusion.

10. The wave height measurement method for complex sea areas based on PPP-B2b and ADCP according to claim 6, characterized in that, The wave height calculation module is specifically used to perform the following steps: After obtaining the fused real-time position and velocity, the vertical displacement over time is obtained by integrating the vertical velocity within a sliding time window. Remove systematic errors and tidal effects from the information on vertical displacement over time; Real-time wave height is extracted from the processed vertical displacement data using the zero-crossing method and spectral analysis.

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