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CN-122018040-A - Method and device for evaluating quasi-static test of shipborne marine gravimeter

CN122018040ACN 122018040 ACN122018040 ACN 122018040ACN-122018040-A

Abstract

The application provides a quasi-static test evaluation method and device for a ship-borne marine gravimeter, which belong to the technical field of marine geophysical measurement, adopt a dual correction mechanism, thereby reconstructing the structural constitution of a data processing functional module, specifically adopt a technical means of synchronously collecting GNSS elevation change data, utilize a GNSS positioning system to be rigidly connected with a gravimeter, continuously record the elevation change data of a ship, calculate a gravity correction value caused by the elevation change according to the elevation change data, deduct a solid tide correction value and the elevation change correction value from the gravity observation data at the same time, obtain an accurate residual observed quantity, break the technical inertia of the prior art which only considers the solid tide correction and ignores the influence of the elevation change, skillfully use the condition of the GNSS system to record the elevation change of the ship, and adopt the dual correction mechanism, solve the problem of inaccurate evaluation result caused by the fluctuation of the ship along with the tide level in a wharf mooring test, and further achieve the technical effect of accurately evaluating the performance of the gravimeter under a quasi-static environment.

Inventors

  • ZHANG BINBIN
  • YANG GANG
  • ZHANG SHIZHONG
  • Fu tengfei

Assignees

  • 自然资源部第一海洋研究所

Dates

Publication Date
20260512
Application Date
20260409

Claims (10)

  1. 1. The method for evaluating the quasi-static test of the shipborne marine gravity meter is characterized by comprising the following steps of: Synchronously recording elevation change data of a GNSS positioning system during the period of continuously recording gravity observation data by a shipborne marine gravity meter, wherein the shipborne marine gravity meter is arranged on a survey ship, the survey ship is moored to a wharf through a mooring rope, and the shipborne marine gravity meter is rigidly connected with the GNSS positioning system; calculating a gravity correction value caused by the elevation change according to the elevation change data; The gravity observation data is subtracted with the solid tide correction value and the gravity correction value caused by the elevation change to obtain the residual observation quantity; and carrying out linear fitting based on the residual observed quantity, and evaluating zero drift parameters of the gravity meter.
  2. 2. The method for evaluating the quasi-static test of the marine gravimeter on board according to claim 1, wherein: the duration of continuously recording the gravity observation data and the elevation change data is not less than 7 days, and the data sampling interval is 1 second.
  3. 3. The method for estimating the quasi-static test of the marine gravity meter on board of claim 1, wherein the gravity correction value caused by the elevation change is calculated by multiplying a first parameter by an elevation change value, the first parameter is a linear coefficient of gravity along with the elevation change, and the value of the first parameter is 0.3086 mGal/m.
  4. 4. The method for evaluating the quasi-static test of the marine gravity meter on board according to claim 1, wherein the gravity observation data and the elevation change data are subjected to time alignment processing before the remaining observation quantity is calculated, and the elevation change data are obtained at 1 second intervals through interpolation processing.
  5. 5. The method for evaluating the quasi-static test of the shipborne marine gravity meter according to claim 1, wherein the linear fitting is a least square method, the slope parameter of the linear fitting represents the linear daily drift rate of the gravity meter, and the zero-point month drift amount is obtained by multiplying the linear daily drift rate by 30 days.
  6. 6. The method for evaluating the quasi-static test of the marine gravimeter on board according to claim 5, wherein: And when the zero month drift amount is less than or equal to 3.0X10 -5 m/s2, judging that the gravity meter meets the offshore measurement requirement.
  7. 7. The method for estimating the quasi-static test of the marine gravity meter on board according to claim 1, wherein the residual observed quantity is drift corrected according to the linear fitting result, a gravity repeated observed value after the drift correction is obtained, and an average value and a standard deviation are calculated according to the gravity repeated observed value.
  8. 8. The utility model provides a quasi-static test evaluation device of on-board marine gravimeter which characterized in that, on-board marine gravimeter quasi-static test evaluation device includes: A shipborne marine gravimeter configured to be mounted on a survey vessel and to continuously collect gravitational observation data in a dock moored state of the vessel; the GNSS positioning device is rigidly connected with the shipborne marine gravity meter and is configured to continuously acquire elevation change data of the ship; the data processing device is in communication connection with the shipborne marine gravity meter and the GNSS positioning device; the data processing apparatus is configured to: receiving gravity observation data acquired by the shipborne marine gravity meter and elevation change data acquired by the GNSS positioning device; calculating a gravity correction value caused by the elevation change according to the elevation change data; The gravity observation data is subtracted with the solid tide correction value and the gravity correction value caused by the elevation change to obtain the residual observation quantity; and carrying out linear fitting on the residual observed quantity, and evaluating zero drift parameters of the gravity meter based on fitting results.
  9. 9. The on-board marine gravimeter quasi-static test assessment device of claim 8, wherein: The data processing device comprises 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 a solid tide correction value and an elevation change correction value; the data fusion module is configured to execute double deduction operation to obtain residual observed quantity; The statistical analysis module is configured to perform linear fitting and parameter calculation on the remaining observables.
  10. 10. An on-board marine gravity gauge quasi-static test evaluation system, characterized in that the on-board marine gravity gauge quasi-static test evaluation system is configured to perform the on-board marine gravity gauge quasi-static test evaluation method of any one of claims 1 to 7.

Description

Method and device for evaluating quasi-static test of shipborne marine gravimeter Technical Field The application relates to the technical field of marine geophysical measurement, in particular to a ship-borne marine gravimeter quasi-static test evaluation method and device. Background The gravity field is one of the most important basic physical fields of the earth, and the ocean gravity field is taken as an important component of the earth gravity field, so that the gravity field has very important application value in the fields of earth science research, ocean resource development, global space standard unification, space engineering guarantee, sea battlefield environment construction, battlefield operation and the like. The current technical means for detecting the ocean gravity field information mainly comprise sea surface shipborne gravity measurement, aviation gravity measurement, satellite height measurement, inversion gravity and the like, the shipborne ocean gravity measurement is the most effective way for acquiring high-precision and high-frequency ocean gravity field information at present, and the precision of ocean gravity data depends on the stability and measurement precision of acquisition equipment. The static observation result of the marine gravity instrument is an important basis for evaluating the stability of the instrument and calculating the zero drift index of the marine gravity instrument. The shipborne marine gravity measurement needs to be carried out by relying on a survey ship, the cost of one day is up to more than hundred thousand, the conventional marine gravity survey voyage organization is almost tens of millions, the cost is huge, and if the instrument index can not meet the requirement of survey specifications, huge cost loss can be caused. How to accurately evaluate the marine gravity instrument by utilizing external data information under the existing working condition is a particularly important and meaningful work. At present, the stability and measurement accuracy of the marine gravimeter are evaluated according to corresponding specifications, and the 8 th part of the GB/T-12763.8-2007 marine survey specification is that the marine gravimeter is placed in a gravity laboratory to stand for a period of time (more than 7 days), the change condition of the gravity meter reading at the position is observed, the zero drift is calculated according to the repeated gravity observation value, the dynamic observation experiment is carried out on the instrument, and the linearity of the zero drift of the instrument is checked before the measurement. The gravity meter must be stable for a long period of time with instrument zero drift (calculated as static test without dynamic test data) and can be used for offshore measurements with a month drift of no more than 3.0x10 -5m/s2. Meanwhile, the DZ/T0356-2020 marine gravity measurement technical specification requires that before and after the operation starts, the investigation ship stops at the wharf and respectively carries out a static stability test of the gravity meter wharf, the starting time is not less than 48 hours, and the zero month drift after tidal correction is not more than 3.0X10 -5m/s2. This is the industry specification or national standard requirements most followed by marine gravimeter survey operations. Marine gravimeter stability has a division of static stability, which represents the metering stabilizing ability of the gravimeter in a stationary state, and dynamic stability, which represents the metering stabilizing ability of the gravimeter in a moving state. The static laboratory needs to install the gravimeter in the gravity laboratory, and the foundation is required to be stable and is not influenced by external factors. However, in the marine gravity measurement operation process, as the ship is inevitably influenced by wave fluctuation, speed and course change, machine vibration, sea wind, ocean current and other interference factors, the marine gravity meter is always in an irregular motion state, so that an end user pays more attention to the dynamic stability of the marine gravity meter, but special test equipment is required for evaluating the dynamic stability, and an ordinary user does not have the condition. Therefore, in practical application, static test data is generally used to replace dynamic test data for quantitative analysis and calculation of stability, but whether the equipment stability under working conditions is consistent with the equipment capability of static experiments needs to be measured according to practical tests. In the field of marine geophysical survey technology, on-board marine gravimeters are important equipment for marine investigation, and performance evaluation thereof is generally required to be performed in a stable environment. The traditional evaluation method mainly adopts two technical routes, namely one is to carry out static test in a land gravity lab