Shipborne marine gravimeter quasi-static test evaluation method and device

Abstract

The invention provides a shipborne marine gravimeter quasi-static test evaluation method and device, belongs to the technical field of marine geophysical measurement, adopts a dual correction mechanism to reconstruct the structural composition of a data processing function module, and specifically adopts a technical means of synchronously collecting GNSS elevation change data to realize accurate measurement. The GNSS positioning system is rigidly connected with the gravimeter to continuously record elevation change data of the ship; calculating a gravity correction value caused by elevation change; the earth tide correction value and the elevation change correction value are deducted from gravity observation data at the same time, the accurate residual observation quantity is obtained, the technical inertia that in the prior art, only earth tide correction is considered, but the elevation change influence is ignored is broken, the GNSS system is ingeniously used for recording the ship elevation change condition, and a dual correction mechanism is adopted; the problem that the evaluation result is inaccurate due to the fact that the ship fluctuates along with the tide level in a wharf mooring test is solved, and then the technical effect of accurately evaluating the performance of the gravimeter in the quasi-static environment is achieved.

Description

Technical Field

[0001] This application relates to the field of marine geophysical measurement technology, and in particular to a quasi-static test evaluation method and apparatus for a shipborne marine gravimeter. Background Technology

[0002] The gravitational field is one of the most important fundamental physical fields on Earth. As a crucial component of Earth's gravitational field, the ocean gravitational field has significant applications in various fields, including Earth science research, marine resource development, global spatial benchmark unification, aerospace engineering support, and the construction and operational use of naval battlefield environments. Currently, the main technical means for detecting ocean gravitational field information include shipborne gravity measurement, airborne gravity measurement, satellite gravity measurement, and satellite altimetry-derived gravity. Shipborne ocean gravity measurement is currently the most effective way to obtain high-precision, high-frequency ocean gravitational field information. The accuracy of ocean gravity data depends on the stability and measurement precision of the acquisition equipment. Static observation results from ocean gravimeters are crucial for evaluating instrument stability and are also important for calculating the zero-point drift index of ocean gravimeters. Shipborne ocean gravity measurement relies on survey vessels, costing over 100,000 yuan per day. Organizing a routine ocean gravity survey voyage costs nearly 10 million yuan, resulting in enormous costs. If the instrument's performance does not meet survey specifications, it will lead to huge cost losses. Therefore, accurately evaluating ocean gravimeters using external data under existing operating conditions is a particularly important and meaningful task.

[0003] Currently, there are corresponding standards for evaluating the stability and measurement accuracy of marine gravimeters. GB / T-12763.8-2007, Marine Survey Specifications, Part 8: Marine Geological and Geophysical Surveys, requires that: the marine gravimeter be placed in a gravity laboratory and left to stand for a period of time (more than 7 days), observing the changes in the instrument readings at that location, and calculating zero drift based on repeated gravity observations; for dynamic observation experiments, the linearity of the zero-point drift during dynamic operation should be checked before measurement. The gravimeter must be stable in zero-point drift (or calculated using static tests if no dynamic test data is available) over a long period, with a monthly drift not exceeding 3.0 × 10⁻⁶. -5 m / s 2 Only under certain conditions can it be used for marine measurements. Furthermore, the DZ / T 0356-2020 Technical Specification for Marine Gravity Measurement requires that: before and after the start of operations, a static stability test of the gravimeter be conducted at the dock when the survey vessel is moored, with an operating time of no less than 48 hours, and the monthly zero-point drift after tidal correction not exceeding 3.0 × 10⁻⁶. -5 m / s 2 This is the industry standard or national standard requirement that is mostly followed during marine gravimeter surveys.

[0004] The stability of marine gravimeters is divided into static stability and dynamic stability. Static stability represents the gravimeter's measurement stability when stationary, while dynamic stability represents its measurement stability when in motion. Static testing requires the gravimeter to be installed within a gravity laboratory with a stable foundation, unaffected by external factors. However, during marine gravity measurements, the gravimeter is constantly in a state of irregular motion due to unavoidable disturbances from factors such as wave fluctuations, changes in speed and course, engine vibration, and sea winds and currents. Therefore, end-users are more concerned with the dynamic stability of the gravimeter. However, evaluating dynamic stability requires specialized testing equipment, which is not readily available to ordinary users. Therefore, in practical applications, static test data is generally used instead of dynamic test data for quantitative stability analysis and calculation. However, whether the equipment's stability under operating conditions is consistent with that of the static test requires actual experimental determination.

[0005] In the field of marine geophysical measurement technology, shipborne marine gravimeters are crucial equipment in marine surveys, and their performance evaluation typically requires a stable environment. Traditional evaluation methods primarily employ two approaches: static testing in a land-based gravity laboratory and quasi-static testing while the survey vessel is moored at the dock. Land-based laboratory tests provide completely static environmental conditions, but require disassembling and transporting the gravimeter from the survey vessel, increasing the risk of equipment damage and extending the evaluation period. Dock-based mooring tests allow the gravimeter to remain in its installed state, avoiding disassembly and transportation; however, the survey vessel is affected by tidal changes while moored, resulting in vertical elevation variations.

[0006] However, existing or mainstream technologies that commonly employ dock mooring tests typically only involve short-term data acquisition of 48 hours and apply solid tide correction only to gravity observation data. This approach suffers from inaccuracies in the evaluation results. This is because, under dock mooring conditions, the survey vessel experiences elevation changes of 5-8 meters due to tidal fluctuations. Based on the linear relationship between gravity and elevation, the gravity change caused by elevation changes can reach the order of 1.5 mGal. Existing technologies only consider solid tide correction while neglecting elevation change correction, resulting in the elevation change effect being included in the gravimeter's zero-point drift parameter, leading to systematic errors in the evaluation results. Furthermore, short-term data acquisition of 48 hours is insufficient to provide enough data for reliable statistical analysis, resulting in inadequate linear fitting accuracy and an inability to accurately reflect the long-term stability characteristics of the gravimeter. Due to industry technological bottlenecks, existing technologies cannot simultaneously solve the problems of elevation change correction and long-term data acquisition while maintaining cost-effectiveness.

[0007] Therefore, it is necessary to address the issues of inaccurate correction for the effects of elevation changes during dock mooring tests and insufficient reliability of short-term data acquisition statistics, in order to meet the requirement of accurately evaluating the performance of shipborne marine gravimeters in a quasi-static environment. Summary of the Invention

[0008] This application provides a quasi-static test evaluation method and apparatus for a shipborne marine gravimeter. It adopts a dual correction mechanism to reconstruct the structure of the data processing functional module, thereby achieving the technical objective of eliminating the influence of elevation changes and accurately evaluating the zero-point drift parameters of the gravimeter.

[0009] Firstly, this application provides a quasi-static test evaluation method for a shipborne marine gravimeter, the method comprising: During the continuous recording of gravity observation data by the shipborne ocean gravimeter, the elevation change data of the GNSS positioning system are recorded simultaneously. The shipborne ocean gravimeter is installed on the survey vessel, which is moored to the dock by a cable. The shipborne ocean gravimeter is rigidly connected to the GNSS positioning system. Calculate the gravity correction value caused by the elevation change based on the elevation change data; The remaining observations are obtained by simultaneously subtracting the solid tide correction value and the gravity correction value caused by the elevation change from the gravity observation data. Linear fitting is performed based on the remaining observations to evaluate the zero-point drift parameters of the gravimeter.

[0010] Optionally, the duration of continuous recording of gravity observation data and elevation change data shall not be less than 7 days, and the data sampling interval shall be 1 second.

[0011] Optionally, the gravity correction value caused by the elevation change is calculated by multiplying the elevation change value by a first parameter, where the first parameter is the linear coefficient of gravity changing with elevation, and the value of the first parameter is 0.3086 mGal / m.

[0012] Optionally, before calculating the remaining observations, the gravity observation data and elevation change data are time-aligned, and the elevation change data are interpolated to obtain data at 1-second intervals.

[0013] Optionally, the linear fitting uses the least squares method, and the slope parameter of the linear fitting represents the linear daily drift rate of the gravimeter. Multiplying the linear daily drift rate by 30 days yields the zero-point monthly drift.

[0014] Optionally, when the zero-point monthly drift is less than or equal to 3.0 × 10 -5 When the speed is m / s², the gravimeter is deemed to meet the requirements for marine measurements.

[0015] Optionally, the remaining observations are drift-corrected based on the linear fitting results to obtain the drift-corrected repeated gravity observations, and the mean and standard deviation are calculated based on the repeated gravity observations.

[0016] Secondly, this application provides a quasi-static test evaluation device for a shipborne marine gravimeter, comprising: The shipborne ocean gravimeter is configured to be installed on the survey vessel and continuously collect gravity observation data while the vessel is moored at the dock. The GNSS positioning device is rigidly connected to the shipborne ocean gravimeter and is configured to continuously collect data on the ship's elevation changes. The data processing device is communicatively connected to the shipborne marine gravimeter and GNSS positioning device; The data processing device is configured as follows: Receive gravity observation data collected by the shipborne marine gravimeter and elevation change data collected by the GNSS positioning device; Calculate the gravity correction value caused by the elevation change based on the elevation change data; The remaining observations are obtained by simultaneously subtracting the solid tide correction value and the gravity correction value caused by the elevation change from the gravity observation data. The remaining observations are linearly fitted, and the zero-point drift parameters of the gravimeter are evaluated based on the fitting results.

[0017] Optionally, the data processing device includes a data receiving module, a correction calculation module, a data fusion module, and a statistical analysis module; The data receiving module is configured to receive gravity observation data and elevation change data; The correction calculation module is configured to calculate solid tide correction values ​​and elevation change correction values; The data fusion module is configured to perform a double deduction operation to obtain the remaining observations; The statistical analysis module is configured to perform linear fitting and parameter calculation on the remaining observations.

[0018] Thirdly, this application provides a quasi-static test evaluation system for a shipborne marine gravimeter, which is configured to perform the aforementioned quasi-static test evaluation method for a shipborne marine gravimeter.

[0019] The beneficial technical effects of this application are as follows: This application provides a quasi-static test evaluation method and device for a shipborne marine gravimeter. It employs a dual correction mechanism, thereby reconstructing the structure of the data processing module. Specifically, it utilizes a technique of synchronously acquiring GNSS elevation change data, rigidly connecting the GNSS positioning system to the gravimeter to continuously record the ship's elevation change data; simultaneously calculating the gravity correction value caused by elevation changes; and subtracting both solid tide correction and elevation change correction values ​​from the gravity observation data to obtain accurate residual observations. This breaks away from the technical inertia of existing technologies that only consider solid tide correction while ignoring the influence of elevation changes. It cleverly utilizes the condition of the GNSS system recording ship elevation changes and employs a dual correction mechanism (simultaneously subtracting the influence of solid tide and elevation change), solving the problem of inaccurate evaluation results caused by ship fluctuations with tide levels during dock mooring tests. This achieves the technical effect of accurately evaluating the gravimeter's performance in a quasi-static environment. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A flowchart illustrating a quasi-static test evaluation method for a shipborne marine gravimeter provided in this application; Figure 2 A schematic diagram of the processing flow for a quasi-static test evaluation method for a shipborne marine gravimeter provided in this application; Figure 3 A frame structure diagram of a quasi-static test evaluation device for a shipborne marine gravimeter provided in this application; Figure 4 A frame structure diagram of a data processing device provided in this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided in this application. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0024] It should be understood that in this application, "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0025] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0026] In the field of marine geophysical measurement technology, shipborne marine gravimeters serve as core measuring equipment. Their main technical structure includes a gravimeter sensor system, a survey vessel, a positioning and navigation system, and a data processing system. Within the technical framework of shipborne marine gravimeter performance evaluation, the main technical component consists of the gravimeter mounted on the survey vessel. The survey vessel, as the platform carrying the gravimeter, is moored to a dock via cables to create a quasi-static test environment. In this dockside mooring test scenario, a data processing module for gravimeter performance evaluation has further evolved. This module is responsible for correcting, calculating, and statistically analyzing the gravity observation data.

[0027] This functional module, due to its traditional correction processing structure, only includes a solid tide correction calculation unit. Limited by the objective fact that the elevation changes of the vessel under moored conditions with the tide level, it suffers from a technical deficiency where the impact of elevation changes cannot be accurately corrected. Specifically, in moored tests, the survey vessel experiences vertical elevation changes ΔH of 5-8 meters with the tide level. Based on the linear relationship between gravity and elevation, the gravity change δgh caused by elevation changes can reach 1.5 mGal. Existing technologies, due to the technical inertia of only considering solid tide correction, only configure solid tide correction calculations in their data processing modules, ignoring the impact of elevation changes on gravity measurements. This results in evaluation results containing systematic errors and failing to accurately reflect the true performance of the gravimeter.

[0028] To overcome the technical problem of inaccurate evaluation results caused by elevation changes during dock mooring trials, this solution employs a dual correction mechanism, thereby reconstructing the structure of the data processing module. Specifically, it utilizes a technique of synchronously acquiring GNSS elevation change data, rigidly connecting the GNSS positioning system with a gravimeter to continuously record the ship's elevation changes; simultaneously, it calculates the gravity correction value caused by the elevation change, using the following formula: Where k is the linear coefficient of gravity as a function of elevation; by simultaneously subtracting the solid tide correction value and the elevation change correction value from the gravity observation data, accurate residual observations are obtained. This achieves the technical objective of eliminating the influence of elevation changes and accurately assessing the zero-point drift parameters of the gravimeter, thus achieving the technical effect of accurate performance evaluation in a quasi-static environment.

[0029] refer to Figure 1 , Figure 2 As shown, this embodiment of the invention provides a quasi-static test evaluation method for a shipborne marine gravimeter, the method comprising: Step 100: While the shipborne marine gravimeter is continuously recording gravity observation data, the elevation change data of the GNSS positioning system is recorded simultaneously.

[0030] Specifically, the shipborne ocean gravimeter is installed on the research vessel, which is moored to the dock by mooring lines. The shipborne ocean gravimeter is rigidly connected to the GNSS positioning system. Quasi-static data evaluation using the shipborne ocean gravimeter is conducted while the research vessel is moored at the dock. During this period, two bow mooring lines and two stern mooring lines are secured to bollards at the dock. In this state, the vessel's main motion is elevation change with the tide level, while the vessel exhibits relatively small free-state changes with surface waves, maintaining relative stability in horizontal position. The research vessel's elevation will change with the ebb and flow of the tide. The difference in elevation, taking Qingdao as an example, can reach up to 5 meters, and sometimes even more than 8 meters. By using a rigid connection to synchronize the elevation changes of the two data acquisition devices, the consistency of elevation change measurements between the gravimeter and the GNSS antenna is resolved, further ensuring the accuracy of elevation correction calculations and thus improving the technical effect of enhancing assessment precision.

[0031] The shipborne oceanographic gravimeter is installed in a dedicated gravimeter room on the research vessel. Air conditioning is used to maintain stable temperature and humidity. The vessel is kept away from heat sources and strong electromagnetic interference. The longitudinal axis of the gravimeter sensor is parallel to or coincides with the longitudinal axis of the research vessel. Navigation and positioning data are connected, and oceanographic gravimeter observation data is recorded for at least 7 days. Gravity observation data and elevation change data are continuously recorded for at least 7 days, with a data sampling interval of 1 second.

[0032] The Veripos LD8 satellite differential positioning system recorded the altitude changes of the GNSS antenna, along with at least seven days of elevation change data. Since the LD8 antenna's installation position and the ocean gravimeter's installation position have a fixed deviation, the elevation changes of the GNSS antenna are consistent with those of the ocean gravimeter, serving as external data for recording the ocean gravimeter's elevation changes. The continuous recording duration of at least seven days and a 1-second sampling interval ensured sufficient data volume and high temporal resolution, thus resolving the issues of insufficient statistical reliability of short-term experimental data and accuracy loss caused by excessively large sampling intervals. This further improved the accuracy of linear fitting and the precision of correction calculations, achieving a data reliability level comparable to that of land-based laboratories.

[0033] Before calculating the remaining observations, the gravity observation data and elevation change data are time-aligned. The elevation change data is interpolated to obtain data with a 1-second interval. Specifically, based on the recording time of the data from the two devices, the elevation change data of the GNSS antenna recorded by the Veripos LD8 satellite differential system is time-aligned with the data collected by the ocean gravimeter, and the tidal change data is interpolated to obtain data with the same sampling interval (1 second). Because of the time alignment and interpolation processing, the problems of asynchronous gravity and elevation data and inconsistent original data sampling intervals are resolved, further ensuring the accuracy of the correction calculation and the precision of data time alignment, thereby achieving the technical effect of improving the reliability of the evaluation results.

[0034] Step 200: Calculate the gravity correction value caused by the elevation change based on the elevation change data.

[0035] Specifically, the gravity correction value caused by elevation change is calculated by multiplying the elevation change value by a first parameter, which is the linear coefficient of gravity changing with elevation, and its value is 0.3086 mGal / m. By using a linear coefficient to convert the elevation change into a gravity correction value and limiting its range, the problem of quantifying the impact of elevation change on gravity measurement and accurately selecting the coefficient is solved, further achieving accurate correction calculation. When this parameter is too large, it will lead to overcorrection; when it is too small, it will lead to undercorrection. This range ensures the best correction effect.

[0036] The spatial correction value of the marine gravimeter is calculated based on the interpolated altitude change data of the GNSS antenna recorded by the Veripos LD8 satellite differential system, using the following formula: ; in, This refers to the elevation change of the marine gravimeter caused by the rise and fall of the ship. The space correction value of the shipborne marine gravimeter is caused by changes in tidal elevation, and the space correction value is as high as 1.5 mGal.

[0037] Step 300: Subtract the solid tide correction value and the gravity correction value caused by the elevation change from the gravity observation data to obtain the remaining observation data.

[0038] Precise observations on the Earth's surface must take into account the effects of solid tides. The gravitational solid tide effect can reach up to ±0.35 mGal, so solid tide corrections need to be calculated and corrected during the evaluation.

[0039] The formula for calculating the theoretical value of solid tides can be found in Appendix B of the Technical Specifications for Gravity Surveys (1:50000) issued by the Ministry of Land and Resources of the People's Republic of China (Ministry of Land and Resources of the People's Republic of China, 2015): ; In the formula, The solid moisture factor is taken as 1.16; For the latitude of the measuring point, Measuring the geocentric latitude of the measuring point It is about The function, with the expression: .

[0040] ; The theoretical value of gravitational solid tides was calculated based on the time series results of static gravimeter tests. Space correction value Observation of gravimeter readings After performing solid tide correction and elevation correction to subtract the effects of solid tide and elevation changes on gravity measurements, the remaining observations are obtained. : ; The above formula not only eliminates the influence of solid tides, but also further eliminates the influence of elevation changes on the measurement results.

[0041] Step 400: Perform linear fitting based on the remaining observations to evaluate the zero-point drift parameters of the gravimeter.

[0042] Linear fitting was performed using the least squares method. The slope parameter of the linear fit represents the linear daily drift rate of the gravimeter. Multiplying the linear daily drift rate by 30 days yields the zero-point monthly drift. When the zero-point monthly drift is less than or equal to 3.0 × 10⁻⁶ days... - 5At a speed of m / s², the gravimeter is deemed to meet the requirements for marine measurements. Drift correction is applied to the remaining observations based on the linear fitting results, yielding drift-corrected repeated gravity observations. The mean and standard deviation are then calculated based on these repeated observations. By employing the least squares method for linear fitting and converting the daily drift rate into the monthly drift, the issues of quantitative analysis of drift trends and standardization of long-term stability assessment in the remaining observations are resolved. This further provides accurate zero-point drift parameters and unified performance evaluation indicators, thereby achieving the technical effect of accurately assessing the long-term stability of the gravimeter.

[0043] By setting a monthly drift assessment threshold, the standardization problem of judging the performance qualification of gravimeters is solved, and a clear acceptance standard is provided. When the threshold is set too high, unqualified instruments will be accepted, and when it is set too low, qualified instruments will be misjudged. This value ensures reasonable performance evaluation.

[0044] Using the least squares method to analyze the remaining observations Perform linear fitting, i.e., determine the remaining observations. The linear change part in: Where g and b are linear fitting parameters, and b represents the linear drift rate of the remaining observations of the gravimeter, based on which the monthly zero-point drift is calculated. ,Right now .

[0045] Based on the linear drift rate calculated above, further drift corrections are applied to the residual observations after solid tide and elevation corrections, which are then used as approximations of repeated observations of gravity data at the ship's berth location: ; This formula applies a drift correction based on the linear drift rate. The corrected result approximates the repeated observations of gravity values ​​at the ship's position points and is used for subsequent arithmetic mean and standard deviation calculations. Then, the average value is calculated based on the corrected gravity observations. : ; Calculate the average value Then, the standard deviation of the experiment is calculated to characterize the precision of the instrument. ; In other words, the standard deviation of repeated gravity observations represents the precision of the marine gravimeter, and the statistical results characterize the instrument's stability, repeatability, and anti-interference ability. N represents the number of series observations.

[0046] Based on the above process, the monthly drift and zero-point drift linearity of a shipborne marine gravimeter during quasi-static testing can be calculated, replacing static testing and offering a more economical, accurate, efficient, and safer alternative to static testing. This invention provides a quasi-static testing evaluation method for shipborne marine gravimeters. The ship is moored at the dock, and a dock-moored test of the shipborne marine gravimeter replaces the static test. This better reflects the environmental conditions under which the marine gravimeter operates, facilitating accurate evaluation of the instrument's zero-point drift parameters and precision. This reflects the equipment's stability, repeatability, and anti-interference capabilities. To address the impact of elevation changes on observation data during dockside mooring tests of shipborne marine gravimeters, this method proposes using external data constraints. The elevation changes of the antenna measured by LD8 are used to characterize the elevation changes of the survey vessel and the gravimeter, correcting for the influence of the main influencing factors, solid tides and ship elevation changes. These two influencing factors are removed before evaluating the quasi-static test data of the marine gravimeter. The greatest advantage of this approach is that it utilizes existing equipment and advantages to achieve synchronous data acquisition, make accurate corrections, and reduce experimental costs. This invention is the first to propose simultaneously recording elevation changes during dockside mooring tests of survey vessels and correcting for gravity value changes caused by elevation changes during zero-point drift and stability assessments. This allows for accurate equipment evaluation, determining whether the instrument meets standard requirements, and facilitating data quality control in subsequent marine gravity measurements.

[0047] This invention provides a quasi-static test evaluation method for a shipborne marine gravimeter. It introduces the concept of measuring elevation changes during dock mooring tests and incorporates elevation corrections during instrument evaluation. This approach improves data accuracy and reduces errors during instrument stability assessment. Furthermore, it eliminates the need for a land-based gravimeter laboratory, avoiding damage during disassembly, assembly, and transportation, thus reducing transportation costs. The elevation acquisition method during dock mooring tests utilizes a rigid structure between the GNSS antenna and the gravimeter. Tide level data measured by the GNSS antenna can be used as elevation change data for the gravimeter. Since every survey vessel is equipped with a GNSS antenna, measurements can be taken without relying on other equipment, further reducing measurement costs. The dock mooring test duration should be no less than 5 days to account for the impact of solid tides and tidal changes on the ship's elevation. Two days is insufficient to accurately reflect and calculate the gravimeter's zero drift, linearity, and accuracy. A minimum of 5 days is recommended, as the preparation time for a typical voyage generally meets this requirement while allowing sufficient data collection for evaluation. In other words, the quasi-static test evaluation method and device for a shipborne marine gravimeter provided in this application adopts a dual correction mechanism, thereby reconstructing the structural composition of the data processing functional module. Specifically, it adopts the technical means of synchronously acquiring GNSS elevation change data, using a rigid connection between the GNSS positioning system and the gravimeter to continuously record the elevation change data of the ship; at the same time, it calculates the gravity correction value caused by the elevation change; and subtracts the solid tide correction value and the elevation change correction value from the gravity observation data to obtain accurate residual observations. This breaks the technical inertia of the prior art that only considers the solid tide correction and ignores the influence of elevation change. It cleverly utilizes the condition of the GNSS system recording the ship's elevation change and adopts a dual correction mechanism (simultaneously subtracting the influence of solid tide and elevation change), which solves the problem of inaccurate evaluation results caused by the ship's fluctuation with the tide level in the dock mooring test, and thus achieves the technical effect of accurately evaluating the performance of the gravimeter in a quasi-static environment.

[0048] This invention overcomes the limitations of traditional wharf tests that only perform solid tide correction, innovatively incorporating GNSS elevation variation data into the correction system to achieve accurate evaluation of gravimeter performance under moored conditions. Through a dual correction mechanism and optimized test parameters, the evaluation accuracy is significantly improved while maintaining cost-effectiveness, providing a new technical standard for the performance quality control of marine gravimeters.

[0049] Based on the same inventive concept, and referring to Figure 3 As shown in the embodiment of this application, a quasi-static test evaluation device for a shipborne marine gravimeter is also provided, comprising: The shipborne ocean gravimeter 101 is configured to be installed on a survey vessel and continuously collect gravity observation data while the vessel is moored at the dock. The GNSS positioning device 102 is rigidly connected to the shipborne ocean gravimeter 101 and is configured to continuously collect data on the elevation changes of the ship. The data processing device 103 is communicatively connected to the shipborne marine gravimeter 101 and the GNSS positioning device 102; The data processing device 103 is configured as follows: Receive gravity observation data collected by the shipborne marine gravimeter and elevation change data collected by the GNSS positioning device; Calculate the gravity correction value caused by the elevation change based on the elevation change data; The remaining observations are obtained by simultaneously subtracting the solid tide correction value and the elevation change correction value from the gravity observation data. The remaining observations are linearly fitted, and the zero-point drift parameters of the gravimeter are evaluated based on the fitting results.

[0050] Optional, see reference Figure 4 As shown, the data processing device 103 includes a data receiving module 1031, a correction calculation module 1032, a data fusion module 1033, and a statistical analysis module 1034; Data receiving module 1031 is configured to receive gravity observation data and elevation change data; The correction calculation module 1032 is configured to calculate the solid tide correction value and the elevation change correction value; Data fusion module 1033 is configured to perform a double deduction operation to obtain the remaining observations; The statistical analysis module 1034 is configured to perform linear fitting and parameter calculation on the remaining observations.

[0051] It should be noted that the division of the various modules in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, these modules can be implemented entirely in software via processing element calls; they can be fully implemented in hardware; or some modules can be implemented by processing element calls to software, while others are implemented in hardware. Additionally, these modules can be fully or partially integrated together, or implemented independently. The processing element mentioned here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above modules can be completed through the integrated logic circuits in the hardware of the processor element or through software instructions.

[0052] Thirdly, this application provides a quasi-static test evaluation system for a shipborne marine gravimeter, which is configured to perform the aforementioned quasi-static test evaluation method for a shipborne marine gravimeter.

[0053] Based on the same inventive concept, this application also provides a quasi-static test evaluation system for a shipborne marine gravimeter that can execute the processing flow provided in an embodiment of a quasi-static test evaluation method for a shipborne marine gravimeter. The quasi-static test evaluation system for a shipborne marine gravimeter provided in this application can be used to execute a quasi-static test evaluation method for a shipborne marine gravimeter in any of the above embodiments. Its implementation principle and technical effects are similar and will not be repeated here. The system provided in this application can be specifically used to execute the scheme provided in the corresponding method embodiment; the specific functions and achievable technical effects will not be repeated here.

[0054] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 5 As shown, the electronic device may include: a processor 21, a memory 22, and computer program instructions stored in the memory 22 and executable on the processor 21. When the processor 21 executes the computer program instructions, it implements a quasi-static test evaluation method for a shipborne marine gravimeter provided in any of the foregoing embodiments.

[0055] Optionally, the various components of the electronic device can be connected via a system bus.

[0056] The memory 22 can be a separate memory unit or a memory unit integrated into the processor. The number of processors can be one or more.

[0057] Optionally, the electronic device may also include a communication interface for interacting with other devices.

[0058] It should be understood that the processor 21 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this application can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0059] The system bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The system bus can be divided into address bus, data bus, control bus, etc. For ease of representation, only one thick line is used in the diagram, but this does not indicate that there is only one bus or one type of bus. Memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0060] All or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a readable memory. When the program is executed, it performs the steps of the above method embodiments; and the aforementioned memory (storage medium) includes: read-only memory (ROM), RAM, flash memory, hard disk, solid-state drive, magnetic tape, floppy disk, optical disk, and any combination thereof.

[0061] The electronic device provided in this application embodiment can be used to perform a quasi-static test evaluation method for a shipborne marine gravimeter provided in any of the above method embodiments. Its implementation principle and technical effect are similar, and will not be described again here.

[0062] This application provides a computer-readable storage medium storing computer-executable instructions. When these instructions are executed on a computer, the computer performs the aforementioned quasi-static test evaluation method for a shipborne marine gravimeter.

[0063] The aforementioned computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory, electrically erasable programmable read-only memory, erasable programmable read-only memory, programmable read-only memory, read-only memory, magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0064] Optionally, a readable storage medium can be coupled to the processor, enabling the processor to read information from and write information to the readable storage medium. Alternatively, the readable storage medium can be an integral part of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0065] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A quasi-static test evaluation method for a shipborne marine gravimeter, characterized in that, The quasi-static test evaluation method for the shipborne marine gravimeter includes: During the continuous recording of gravity observation data by the shipborne ocean gravimeter, the elevation change data of the GNSS positioning system are recorded simultaneously. The shipborne ocean gravimeter is installed on the survey vessel, which is moored to the dock by a cable. The shipborne ocean gravimeter is rigidly connected to the GNSS positioning system. Calculate the gravity correction value caused by the elevation change based on the elevation change data; The remaining observations are obtained by simultaneously subtracting the solid tide correction value and the gravity correction value caused by the elevation change from the gravity observation data. Linear fitting is performed based on the remaining observations to evaluate the zero-point drift parameters of the gravimeter.

2. The quasi-static test evaluation method for shipborne marine gravimeters according to claim 1, characterized in that: The duration of continuous recording of gravity observation data and elevation change data shall not be less than 7 days, and the data sampling interval shall be 1 second.

3. The quasi-static test evaluation method for shipborne marine gravimeters according to claim 1, characterized in that: The gravity correction value caused by the elevation change is calculated by multiplying the elevation change value by a first parameter, which is the linear coefficient of gravity changing with elevation, and the value of the first parameter is 0.3086 mGal / m.

4. The quasi-static test evaluation method for shipborne marine gravimeters according to claim 1, characterized in that: Before calculating the remaining observations, the gravity observation data and elevation change data are time-aligned, and the elevation change data are interpolated to obtain data at 1-second intervals.

5. The quasi-static test evaluation method for shipborne marine gravimeters according to claim 1, characterized in that: The linear fitting uses the least squares method. The slope parameter of the linear fitting represents the linear daily drift rate of the gravimeter. Multiplying the linear daily drift rate by 30 days yields the zero-point monthly drift.

6. The quasi-static test evaluation method for shipborne marine gravimeters according to claim 5, characterized in that: When the zero-point monthly drift is less than or equal to 3.0 × 10 -5 When the speed is m / s², the gravimeter is deemed to meet the requirements for marine measurements.

7. The quasi-static test evaluation method for shipborne marine gravimeters according to claim 1, characterized in that: The remaining observations are drift-corrected based on the linear fitting results to obtain the drift-corrected repeated gravity observations, and the mean and standard deviation are calculated based on the repeated gravity observations.

8. A quasi-static test evaluation device for a shipborne marine gravimeter, characterized in that, The shipborne marine gravimeter quasi-static test evaluation device includes: The shipborne ocean gravimeter is configured to be installed on the survey vessel and continuously collect gravity observation data while the vessel is moored at the dock. The GNSS positioning device is rigidly connected to the shipborne ocean gravimeter and is configured to continuously collect data on the ship's elevation changes. The data processing device is communicatively connected to the shipborne marine gravimeter and GNSS positioning device; The data processing device is configured as follows: Receive gravity observation data collected by the shipborne marine gravimeter and elevation change data collected by the GNSS positioning device; Calculate the gravity correction value caused by the elevation change based on the elevation change data; The remaining observations are obtained by simultaneously subtracting the solid tide correction value and the gravity correction value caused by the elevation change from the gravity observation data. The remaining observations are linearly fitted, and the zero-point drift parameters of the gravimeter are evaluated based on the fitting results.

9. The quasi-static test evaluation device for a shipborne marine gravimeter according to claim 8, characterized in that: The data processing device includes a data receiving module, a correction calculation module, a data fusion module, and a statistical analysis module; The data receiving module is configured to receive gravity observation data and elevation change data; The correction calculation module is configured to calculate solid tide correction values ​​and elevation change correction values; The data fusion module is configured to perform a double deduction operation to obtain the remaining observations; The statistical analysis module is configured to perform linear fitting and parameter calculation on the remaining observations.

10. A quasi-static test evaluation system for a shipborne marine gravimeter, characterized in that, The shipborne marine gravimeter quasi-static test evaluation system is configured to perform the shipborne marine gravimeter quasi-static test evaluation method as described in any one of claims 1 to 7.

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