Seafloor parameter array subbottom profile measurement correction method

Abstract

The application discloses a seabed parameter array shallow stratigraphic profile measurement correction method in the technical field of seabed parameter array shallow stratigraphic profile measurement correction, comprising a double-antenna positioning module and an inertial navigation module, and the method comprises the following steps: step one: obtaining carrier first positioning information based on the double-antenna positioning system; solving carrier first attitude data based on the first positioning information; step two: calculating navigation coordinate system motion data based on the inertial navigation module, and obtaining carrier second attitude data; step three: calculating correction attitude data based on the first attitude and the second attitude data; step four: correcting shallow stratigraphic profile original data based on the correction attitude data, and obtaining high-precision parameter array shallow stratigraphic profile parameter data; the resolution of the shallow stratigraphic profile data reaches the centimeter level, and high-precision high-resolution seabed stratigraphic measurement of the ocean is truly realized.

Description

Technical Field

[0001] The present invention relates to the technical field of seabed parametric array shallow stratum profile measurement and correction, in particular to a seabed parametric array shallow stratum profile measurement and correction method. Background Art

[0002] Marine seismic surveys have found that the original stratigraphic profiles collected by parametric array shallow-layer profilers are significantly affected by wind and wave conditions. In particular, when wind and wave conditions are poor, the shallow-layer profile reflection events are affected by the ship's roll and pitch, resulting in wave-like distortions. This results in poor shallow-seabed detection and requires rework. Therefore, targeted technical methods and measures are needed to reduce the impact of wave-induced ship roll, pitch, and heave errors on parametric array shallow-layer profile acquisition, thereby obtaining true stratum reflection acoustic wave travel time signals and improving shallow-seabed detection accuracy and resolution. Conventional parametric array shallow-layer profile measurements generally do not employ wave compensation or surge filters to measure wave-induced ship roll, pitch, and heave errors for seabed topography correction. The technical method for configuring a surge filter is relatively simple, but the main disadvantage is that configuring a single surge filter has limitations. In particular, when the survey vessel deviates from the survey line and turns, the hull will tilt to a certain extent to maintain balance. The surge filter will experience data output delays due to the eccentric force, and surge compensation errors will occur due to the influence of centrifugal acceleration. The error caused by the eccentricity of the transducer is a false error and is difficult to correct accurately. Figure 1 Between points 25 and 50 of the track, the ship yaws due to turning. If the swell data is used to correct the acoustic travel time, it will create the illusion of convex or concave seabed topography, resulting in poor recording of the original shallow layer profile. Figure 2 ), which affects the resolution of shallow formations. Therefore, the conventional surge filter method cannot effectively solve the problem of acoustic wave travel time correction in shallow formation profiles of parametric array.

[0003] Based on this, the present invention designs a seabed parametric array shallow stratum profile measurement correction method to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for correcting shallow stratum profile measurements using a seafloor parametric array to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a method for measuring and correcting a shallow layer profile using a seabed parametric array, comprising a dual-antenna positioning module and an inertial navigation module. The method comprises the following steps:

[0006] Step 1: obtaining first positioning information of the vehicle based on the dual-antenna positioning system; and calculating first posture data of the vehicle based on the first positioning information;

[0007] Step 2: Calculating a navigation coordinate system based on the inertial navigation module to obtain second posture data of the vehicle;

[0008] Step 3: Calculate corrected posture data based on the first posture data and the second posture data,

[0009] Step 4: Correct the original shallow layer profile data based on the corrected attitude data to obtain high-precision parametric array shallow surface profile parameter data.

[0010] As a further solution of the present invention, the inertial navigation module includes a gyroscope and an accelerometer, the gyroscope is used to obtain the coordinate data of the vehicle and establish a navigation coordinate system; the accelerometer is used to output and calculate the speed and position of the vehicle in the navigation coordinate system; based on the navigation coordinate system and the speed and position of the vehicle in navigation, the second posture data is calculated.

[0011] As a further solution of the present invention, the specific process of correcting the original data of the shallow stratum profile based on the first posture data and the second posture data includes: obtaining the first posture data and the second posture data for data solution, performing posture data analysis, and obtaining combined posture data; extracting the heave value of the posture data based on the combined posture data; and correcting the parametric array profile acoustic wave reflection sync axis based on the heave value to obtain more accurate parametric array shallow stratum profile data.

[0012] As a further solution of the present invention, the heave value corrects the acoustic wave reflection event of the shallow stratum profile of the parametric array, including acoustic wave travel time correction: the acoustic wave travel time correction is specifically calculated as follows:

[0013]

[0014] Where: t': corrected acoustic travel time; t: pre-corrected acoustic travel time; Δt: round-trip time of heave value; d: heave value recorded by the inertial navigation module; v: water speed.

[0015] Based on the corrected acoustic travel time, the parametric array shallow stratum profile data is band-pass filtered. The band-pass filtering calculation formula is as follows:

[0016]

[0017] Where: X(t): time domain acoustic wave signal; X(w): frequency domain acoustic wave signal; H(w): bandpass filter; X^(w): filtered frequency domain signal; X^(t): filtered time domain signal.

[0018] As a further solution of the present invention, the parametric array shallow layer profile data also includes post-processing of the original shallow layer profile data. The specific steps of the post-processing include: obtaining pre-processed profile data by attitude correction, filtering, and noise suppression of the original shallow layer profile, and reconstructing the resolution of the pre-processed profile data to obtain high-precision parametric array shallow layer profile data.

[0019] As a further solution of the present invention, the dual-antenna positioning system is used for data acquisition; the inertial navigation module is used to: after the navigation coordinate system is established by the output of the gyroscope, calculate the speed and position of the vehicle in the navigation coordinate system according to the output of the accelerometer.

[0020] As a further embodiment of the present invention, the system further includes a transducer, including a main antenna, an auxiliary antenna, and an IPOS host; the transducer is used to convert electrical energy, mechanical energy, or acoustic energy from one form of energy into another form of energy; the main antenna is used for main reception of electromagnetic waves; the auxiliary antenna is used for diversity reception of electromagnetic waves; and the IPOS host is used as a measurement machine for storage device performance testing.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] To verify the effectiveness and practicality of this invention, inertial navigation technology was applied to parametric array shallow subsurface profile measurements to reduce wave-induced errors in ship roll, pitch, and heave. The seafloor was corrected to be flat, restoring the true subsurface structure. This improved the accuracy of shallow subsurface measurements and optimized the resolution of shallow strata. Multiple tests have demonstrated that using inertial navigation attitude parameter processing and correction can obtain a true shallow subsurface profile structure, achieving centimeter-level resolution for shallow subsurface profile data, truly achieving high-precision and high-resolution marine subsurface measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of comparative analysis of track, measured instantaneous heave value and synchronous water depth;

[0024] Figure 2 It is the original profile of the shallow stratum of the parametric array;

[0025] Figure 3 This is a schematic diagram of the combination of the parametric array acquisition system and the inertial navigation equipment;

[0026] Figure 4 The overall technical flow chart of the parametric array shallow section acoustic wave travel time correction;

[0027] Figure 5 To measure the original profile of the attitude data and parametric array shallow stratum profile obtained synchronously;

[0028] Figure 6 This is the shallow stratum profile corrected using the extracted heave value data;

[0029] Figure 7 This is the profile of shallow stratum profile measurement results;

[0030] Figure 8 Comparison chart before (left) and after (right) the application of inertial navigation technology. DETAILED DESCRIPTION

[0031] See also Figure 1-8 The present invention provides a technical solution: a method for measuring and correcting a shallow layer profile using a seabed parametric array, comprising a dual-antenna positioning module and an inertial navigation module. The method comprises the following steps:

[0032] Step 1: obtaining first positioning information of the vehicle based on the dual-antenna positioning system; and calculating first posture data of the vehicle based on the first positioning information;

[0033] Step 2: Calculating a navigation coordinate system based on the inertial navigation module to obtain second posture data of the vehicle;

[0034] Step 3: Calculate corrected posture data based on the first posture data and the second posture data,

[0035] Step 4: Correct the original shallow layer profile data based on the corrected attitude data to obtain high-precision parametric array shallow surface profile parameter data.

[0036] As a further solution of the present invention, the inertial navigation module includes a gyroscope and an accelerometer, the gyroscope is used to obtain the coordinate data of the vehicle and establish a navigation coordinate system; the accelerometer is used to output and calculate the speed and position of the vehicle in the navigation coordinate system; based on the navigation coordinate system and the speed and position of the vehicle in navigation, the second posture data is calculated.

[0037] As a further solution of the present invention, the specific process of correcting the original data of the shallow stratum profile based on the first posture data and the second posture data includes: obtaining the first posture data and the second posture data for data solution, performing posture data analysis, and obtaining combined posture data; extracting the heave value of the posture data based on the combined posture data; and correcting the parametric array profile acoustic wave reflection sync axis based on the heave value to obtain more accurate parametric array shallow stratum profile data.

[0038] As a further solution of the present invention, the heave value corrects the acoustic wave reflection event of the shallow stratum profile of the parametric array, including acoustic wave travel time correction: the acoustic wave travel time correction is specifically calculated as follows:

[0039]

[0040] Where: t': corrected acoustic travel time; t: pre-corrected acoustic travel time; Δt: round-trip time of heave value; d: heave value recorded by the inertial navigation module; v: water speed.

[0041] Based on the corrected acoustic travel time, the parametric array shallow stratum profile data is band-pass filtered. The band-pass filtering calculation formula is as follows:

[0042]

[0043] Where: X(t): time domain acoustic wave signal; X(w): frequency domain acoustic wave signal; H(w): bandpass filter; X^(w): filtered frequency domain signal; X^(t): filtered time domain signal ( Figure 6 ).

[0044] As a further solution of the present invention, the parametric array shallow stratum profile data further includes post-processing the original shallow stratum profile data, and the specific steps of the post-processing include: performing attitude correction, filtering processing, and noise suppression on the original shallow stratum profile to obtain pre-processed profile data, reconstructing the resolution of the pre-processed profile data to obtain high-precision parametric array shallow stratum profile data; outputting the result profile ( Figure 7 ), truly reflects the seabed topography and underlying stratum structure, improves the resolution of seabed shallow stratum profile data, and truly realizes high-precision parametric array shallow stratum profile measurement.

[0045] As a further solution of the present invention, the dual-antenna positioning system is used for data acquisition; the inertial navigation module is used to: after the navigation coordinate system is established by the output of the gyroscope, calculate the speed and position of the vehicle in the navigation coordinate system according to the output of the accelerometer.

[0046] As a further embodiment of the present invention, the system further includes a transducer, including a main antenna, an auxiliary antenna, and an IPOS host; the transducer is used to convert electrical energy, mechanical energy, or acoustic energy from one form of energy into another form of energy; the main antenna is used for main reception of electromagnetic waves; the auxiliary antenna is used for diversity reception of electromagnetic waves; and the IPOS host is used as a measurement machine for storage device performance testing.

[0047] Attitude data output: The attitude data of the inertial navigation module supports RS232 standardized output for use with other marine equipment, providing high-precision roll, heave, heading, speed, time and other data outputs. The heave value data will be used to correct the original data of shallow layer profile measurement.

[0048] Combined Inertial Navigation System + Parametric Array Shallow Profile Measurement System Solution: The combined inertial navigation module consists of an inertial measurement unit, a deck unit control system, and a dual-antenna positioning system. Combined inertial navigation technology was applied to offshore trials of parametric array shallow subsurface profile measurements, acquiring synchronized motion sensor data (swell, roll, pitch, heading, and yaw, etc.).

[0049] In order to verify the effectiveness and practicality of this invention, inertial navigation technology is applied to the parametric array shallow stratum profile measurement to reduce the ship rolling, pitching and heave errors caused by waves. Figure 8 This is a comparison before and after the application of inertial navigation technology. After processing and correction, the seabed strata have become flatter, restoring the true structure of the seabed. This improves the measurement accuracy of shallow seabed strata and optimizes the resolution of shallow strata. Multiple tests have proven that using inertial navigation attitude parameter processing and correction can obtain the true structure of shallow strata profiles, achieving centimeter-level resolution for shallow strata profile data, truly achieving high-precision and high-resolution marine seabed strata measurement.

[0050] System sea trial: A certain work area in Bohai Sea was selected to conduct a system sea trial in conjunction with the project. The parametric array shallow layer profile measurement system scheme under the application of the combined inertial guidance system was adopted to simultaneously obtain the output attitude data of the combined inertial guidance system and the original data of the parametric array shallow layer profile measurement ( Figure 5 Finally, based on the attitude data obtained from the inertial navigation system, attitude data analysis is performed to extract the heave value and correct the parametric array shallow section acoustic wave reflection event, thereby achieving the purpose of improving the resolution and imaging accuracy of the parametric array shallow formation section data.

Claims

1. A method for correcting shallow-sediment profile measurements using a seafloor parametric array, comprising a dual-antenna positioning module and an inertial navigation module, characterized in that: The seabed parametric array shallow stratum profile measurement correction method comprises the following steps: Step 1: obtaining first positioning information of the vehicle based on the dual-antenna positioning module; and calculating first posture data of the vehicle based on the first positioning information; Step 2: Calculating a navigation coordinate system based on the inertial navigation module to obtain second posture data of the vehicle; Step 3: Calculating corrected posture data based on the first posture data and the second posture data; Step 4: Correcting the original shallow layer profile data based on the corrected attitude data to obtain high-precision parametric array shallow surface profile parameter data; The specific process of step three includes: obtaining the first attitude data and the second attitude data for data solution, performing attitude data analysis, and obtaining combined attitude data; extracting the heave value of the attitude data based on the combined attitude data; and correcting the parametric array profile acoustic wave reflection event based on the heave value to obtain more accurate parametric array shallow stratum profile data; The heave value corrects the acoustic wave reflection event of the parametric array profile, including acoustic wave travel time correction: the acoustic wave travel time correction is specifically calculated as follows: Where: t´: corrected acoustic wave travel time; t: pre-corrected acoustic wave travel time; Δt: round-trip time of heave value; d: heave value recorded by the inertial navigation module; v: water speed; Based on the corrected acoustic travel time, the parametric array shallow stratum profile data is band-pass filtered. The band-pass filtering calculation formula is as follows: in: : Time domain acoustic wave signal; : frequency domain acoustic wave signal; H(w): bandpass filter; : frequency domain signal after filtering; : Filtered time domain signal.

2. The method for correcting shallow stratum profile measurement using a seafloor parametric array according to claim 1, wherein: The inertial navigation module includes a gyroscope and an accelerometer. The gyroscope is used to obtain the coordinate data of the vehicle and establish a navigation coordinate system. The accelerometer is used to output and calculate the speed and position of the vehicle in the navigation coordinate system. Based on the navigation coordinate system and the speed and position of the vehicle during navigation, the second attitude data is calculated.

3. The method for calibrating shallow stratum profile measurement using a seafloor parametric array according to claim 1, wherein: The dual-antenna positioning module is used for data collection; the inertial navigation module is used to: after the navigation coordinate system is established by the output of the gyroscope, calculate the speed and position of the vehicle in the navigation coordinate system according to the output of the accelerometer.

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