Method for establishing high-precision gravity field model

Abstract

A high-precision gravity field model establishing method comprises the steps of firstly obtaining gravity observation data of a plurality of stations, then carrying out downsampling processing on the data, then carrying out theoretical earth tide correction on the data, and then carrying out wrong data, kick data and continuous grid-dropping data identification on the data, then error data, kick data and continuous grid-dropping data in the data are corrected, theoretical earth tide correction, tide correction, air pressure correction, sea tide correction and extreme tide correction are carried out on the data, and then a high-precision gravity field model is obtained; the gravity observation data is actually measured and generated in the region of China, so that a large amount of assignment calculation is not needed, and the generation efficiency of the gravity field model is relatively high. Therefore, according to the design, all nodes do not need to be calculated, and the gravity field model generation efficiency is high.

Description

Technical Field

[0001] The present invention relates to a method for establishing a gravity field model, belongs to the technical field of earth gravity field models, and in particular to a method for establishing a high-precision gravity field model. Background Art

[0002] When conducting earthquake gravity observations, it is often necessary to use the Earth's gravity field model to conduct research in order to capture the distribution and dynamic changes of matter inside the Earth. These changes are closely related to the gestation and occurrence of earthquakes.

[0003] A Chinese patent application with application number 202110656206.X and application date June 11, 2021, discloses a multi-source gravity data fusion method, including the following steps: gravity field data source organization, grid construction, grid value assignment, error correction, and grid data output. This multi-source gravity data fusion method only requires a small amount of measured gravity data as control points. By constructing a multi-layer grid, it fuses gravity data information from different sources and outputs gridded gravity data. Although this design outputs gravity data by fusing multiple data sources, it still has the following drawbacks: In this design, a basic grid is formed first, and then multiple data sources are superimposed on the basic grid to form a multi-layer grid. Then, the data on each grid node in the multi-layer grid is assigned and calculated to output the gravity field model. There are a large number of grid nodes, and each grid node needs to be calculated to output the gravity field data. Therefore, the amount of calculation is large, and the efficiency of gravity field model generation is low.

[0004] The information disclosed in this background technology section is only intended to increase understanding of the overall background of the application and should not be considered as an admission or any form of suggestion that the information constitutes the prior art already known to ordinary technicians in this field. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects and problems in the prior art that all nodes need to be calculated and the gravity field model generation efficiency is low, and to provide a high-precision gravity field model establishment method that does not require the calculation of all nodes and has a high gravity field model generation efficiency.

[0006] To achieve the above objectives, the technical solution of the present invention is: A method for establishing a high-precision gravity field model, comprising the following steps: The first step is to obtain gravity observation data from multiple stations, downsample the gravity observation data, and obtain low-sampling rate observation data; then convert the low-sampling rate observation data into gravity value observation data based on the gravimeter grid value coefficient, and then perform theoretical solid tide correction on the gravity value observation data to obtain gravity value correction data; Step 2: firstly, performing error data identification on the gravity value correction data to obtain first gravity value normal data and error data, then outputting the first gravity value normal data and error data together to obtain primary gravity value data, then performing jump data identification on the primary gravity value data to obtain second gravity value normal data, jump data and error data, then outputting the second gravity value normal data, jump data and error data together to obtain secondary gravity value data, then performing continuous drop-grid data identification on the secondary gravity value data to obtain third gravity value normal data, error data, jump data and continuous drop-grid data, then outputting the third gravity value normal data, error data, jump data and continuous drop-grid data together to obtain tertiary gravity value data, then performing correction processing on the error data, jump data and continuous drop-grid data in the tertiary gravity value data to obtain gravity value correction data; Step 3: First, perform theoretical solid tide correction on the gravity value correction data, and then obtain gravity solid tide preprocessing data, then perform tidal correction on the gravity solid tide preprocessing data, and then obtain gravity tidal correction data, then perform air pressure correction on the gravity tidal correction data, and then obtain gravity air pressure correction data, then perform ocean tide correction on the gravity air pressure correction data, and then obtain gravity ocean tide correction data, then perform extreme tide correction on the gravity ocean tide correction data, and then obtain gravity extreme tide correction data, and then obtain a high-precision gravity field model based on the gravity extreme tide correction data, and this method ends.

[0007] In the second step, the erroneous data identification is performed by using a derivative method or a probability statistics method.

[0008] In the second step, the sudden jump data is identified by using a derivative method or a threshold method.

[0009] In the second step, the continuous frame-dropping data identification is performed by using a derivative method.

[0010] In the second step, the correction process is to first use the difference between the erroneous data, the data before the erroneous data and the data after the erroneous data as a one-time discontinuous grid correction value, and then use the one-time discontinuous grid correction value to correct the erroneous data; Then the difference between the sudden jump data, the data before the sudden jump data and the data after the sudden jump data is used as the secondary discontinuous grid correction value, and the sudden jump data is corrected using the secondary discontinuous grid correction value; Then the difference between the continuous dropped frame data, the data before the continuous dropped frame data and the data after the continuous dropped frame data is used as the three-time intermittent dropped frame correction value, and then the three-time intermittent dropped frame correction value is used to correct the continuous dropped frame data.

[0011] In the first step, the downsampling process is to first downsample the gravity observation data using an IIR filter to obtain intermediate data, then perform differential calculation on the intermediate data, and then obtain low-sampling rate observation data.

[0012] In the first step, the gravimeter grid value coefficient includes an additive constant correction value and a nonlinear zero drift correction value.

[0013] In the third step, the tidal correction is performed by first calculating the theoretical solid tide using a precise tidal model.

[0014] In the third step, the air pressure correction is performed by using the same-site air pressure observation data and the air pressure admittance value.

[0015] In the third step, the ocean tide correction is performed by using the Nao99b and Nao99bj global and regional ocean tide models to forward simulate the ocean tide load effects of the stations.

[0016] In the third step, the polar tide correction is performed by using the polar motion parameters to calculate the polar tide correction data of the station.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. In a method for establishing a high-precision gravity field model of the present invention, the method comprises the following steps: a first step: first obtaining gravity observation data from multiple stations, then downsampling the aforementioned data, then converting the aforementioned data into gravity value observation data, and then performing theoretical solid tide correction on the aforementioned data; a second step: first performing error data identification, sudden jump data identification, and continuous frame drop data identification on the aforementioned data, and then correcting the aforementioned data to obtain gravity value correction data; a third step: first performing theoretical solid tide correction, tidal correction, air pressure correction, sea tide correction, and extreme tide correction on the aforementioned data in sequence, and then obtaining gravity extreme tide correction data, and then obtaining a high-precision gravity field model based on the gravity extreme tide correction data. The advantages of the present invention also include: First, gravity observation data is obtained through actual measurements at stations, without the need for calculations. This greatly reduces the amount of calculations and effectively improves the efficiency of generating gravity field models. Second, the gravity field models used in existing technologies (such as the EGM2008 gravity field model) lack actual gravity observation data within my country, resulting in observation errors of 3 to 5 milligal in eastern my country and 10 to 15 milligal in western China (refer to relevant gravity field model research literature). However, the gravity observation data at the stations are actually measured within my country, so the aforementioned errors will not occur. The resulting gravity field model can accurately reflect the actual situation of my country's gravity field. Third point: The gravity observation data has been revised and corrected many times to eliminate erroneous data, sudden jump data and discontinuous data. Therefore, the gravity field model is established with higher precision data, which makes the gravity field model more accurate. Therefore, the present invention does not need to calculate all nodes, and the gravity field model generation efficiency is high.

[0018] 2. In the method for establishing a high-precision gravity field model of the present invention, in the second step, the error data identification is performed using a derivative method or a probability statistics method, the jump data identification is performed using a derivative method or a threshold method, and the continuous drop data identification is performed using a derivative method. The correction processing is performed by using the difference between the error data, the jump data, the continuous drop data, and the preceding and following data as the intermittent drop correction value, and then using the intermittent drop correction value to perform correction processing. When applied, the error data, the jump data, and the continuous drop data are all abnormal data. Correcting the abnormal data can prevent the abnormal data from affecting the accuracy of the gravity field model. Therefore, the present invention is better for handling abnormal data.

[0019] 3. In a method for establishing a high-precision gravity field model according to the present invention, in the first step, downsampling involves first downsampling the gravity observation data using an IIR filter, and then performing a differential calculation on the data. In the first step, the gravimeter grid value coefficient includes an additive constant correction value and a nonlinear zero drift correction value. When applied, excessively high sampling frequencies can lead to overly complex and irregular data changes, resulting in distorted data during data processing, which can affect the accuracy of subsequent gravity field model establishment. Differential calculations make the changing characteristics and patterns in the data more apparent, thereby providing more valuable information for subsequent construction of gravity field models. In the downsampling process, a segmented sampling algorithm is used to divide the data into multiple small segments, which are then spliced together. At this time, the additive constant correction value and the nonlinear zero drift correction value are used for correction. Therefore, the present invention has a good data preprocessing effect.

[0020] 4. In a high-precision gravity field model establishment method of the present invention, in the third step, the tidal correction is first performed using a precise tidal model to perform tidal correction, the pressure correction is performed using the same-site pressure observation data and the pressure admittance value to perform pressure correction, the ocean tide correction is performed using the ocean tide load influence of the Nao99b and Nao99bj global and regional ocean tide models forward modeling stations to perform ocean tide correction, and the extreme tide correction is performed using the extreme tide correction data of the polar shift parameter calculation station to perform extreme tide correction. When applied, after the tidal correction, pressure correction, ocean tide correction and extreme tide correction, the affected part in the data is eliminated, further improving the accuracy of the data. Therefore, the processing accuracy of the present invention is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the present invention.

[0022] Figure 2 This is a flowchart of Example 3.

[0023] Figure 3 This is a flowchart of Example 2.

[0024] Figure 4 This is a flowchart of Example 4.

[0025] Figure 5 yes Figure 1 Flowchart of theoretical solid tide correction.

[0026] Figure 6 This is the first application result diagram of the present invention.

[0027] Figure 7 This is a second application result diagram of the present invention.

[0028] Figure 8 It is a schematic diagram of the procedure when the present invention is applied. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] See Figure 1 — Figure 8 A method for establishing a high-precision gravity field model, comprising the following steps: The first step is to obtain gravity observation data from multiple stations, downsample the gravity observation data, and obtain low-sampling rate observation data; then convert the low-sampling rate observation data into gravity value observation data based on the gravimeter grid value coefficient, and then perform theoretical solid tide correction on the gravity value observation data to obtain gravity value correction data; Step 2: firstly, performing error data identification on the gravity value correction data to obtain first gravity value normal data and error data, then outputting the first gravity value normal data and error data together to obtain primary gravity value data, then performing jump data identification on the primary gravity value data to obtain second gravity value normal data, jump data and error data, then outputting the second gravity value normal data, jump data and error data together to obtain secondary gravity value data, then performing continuous drop-grid data identification on the secondary gravity value data to obtain third gravity value normal data, error data, jump data and continuous drop-grid data, then outputting the third gravity value normal data, error data, jump data and continuous drop-grid data together to obtain tertiary gravity value data, then performing correction processing on the error data, jump data and continuous drop-grid data in the tertiary gravity value data to obtain gravity value correction data; Step 3: First, perform theoretical solid tide correction on the gravity value correction data, and then obtain gravity solid tide preprocessing data, then perform tidal correction on the gravity solid tide preprocessing data, and then obtain gravity tidal correction data, then perform air pressure correction on the gravity tidal correction data, and then obtain gravity air pressure correction data, then perform ocean tide correction on the gravity air pressure correction data, and then obtain gravity ocean tide correction data, then perform extreme tide correction on the gravity ocean tide correction data, and then obtain gravity extreme tide correction data, and then obtain a high-precision gravity field model based on the gravity extreme tide correction data, and this method ends.

[0031] In the second step, the erroneous data identification is performed by using a derivative method or a probability statistics method.

[0032] In the second step, the sudden jump data is identified by using a derivative method or a threshold method.

[0033] In the second step, the continuous frame-dropping data identification is performed by using a derivative method.

[0034] In the second step, the correction process is to first use the difference between the erroneous data, the data before the erroneous data and the data after the erroneous data as a one-time discontinuous grid correction value, and then use the one-time discontinuous grid correction value to correct the erroneous data; Then the difference between the sudden jump data, the data before the sudden jump data and the data after the sudden jump data is used as the secondary discontinuous grid correction value, and the sudden jump data is corrected using the secondary discontinuous grid correction value; Then the difference between the continuous dropped frame data, the data before the continuous dropped frame data and the data after the continuous dropped frame data is used as the three-time intermittent dropped frame correction value, and then the three-time intermittent dropped frame correction value is used to correct the continuous dropped frame data.

[0035] In the first step, the downsampling process is to first downsample the gravity observation data using an IIR filter to obtain intermediate data, then perform differential calculation on the intermediate data, and then obtain low-sampling rate observation data.

[0036] In the first step, the gravimeter grid value coefficient includes an additive constant correction value and a nonlinear zero drift correction value.

[0037] In the third step, the tidal correction is performed by first calculating the theoretical solid tide using a precise tidal model.

[0038] In the third step, the air pressure correction is performed by using the same-site air pressure observation data and the air pressure admittance value.

[0039] In the third step, the ocean tide correction is performed by using the Nao99b and Nao99bj global and regional ocean tide models to forward simulate the ocean tide load effects of the stations.

[0040] In the third step, the polar tide correction is performed by using the polar motion parameters to calculate the polar tide correction data of the station.

[0041] The supplementary description of the present invention is as follows: The tidal correction described in the present invention refers to: deducting the tides of the solid earth and the load tides caused by the ocean tides from the gravity observation data. The tides of the solid earth can be obtained through a solid tide model, and the load tides caused by the ocean tides can be obtained through an ocean tide model. The solid tide model and the ocean tide model are combined to obtain the tidal parameters used for tidal correction (when combining, a phase correction of 180 degrees must be added in areas with latitudes greater than 35.26 degrees).

[0042] Example 1: See Figure 1 — Figure 8 A method for establishing a high-precision gravity field model, comprising the following steps: The first step is to obtain gravity observation data from multiple stations, downsample the gravity observation data, and obtain low-sampling rate observation data; then convert the low-sampling rate observation data into gravity value observation data based on the gravimeter grid value coefficient, and then perform theoretical solid tide correction on the gravity value observation data to obtain gravity value correction data; Step 2: firstly, performing error data identification on the gravity value correction data to obtain first gravity value normal data and error data, then outputting the first gravity value normal data and error data together to obtain primary gravity value data, then performing jump data identification on the primary gravity value data to obtain second gravity value normal data, jump data and error data, then outputting the second gravity value normal data, jump data and error data together to obtain secondary gravity value data, then performing continuous drop-grid data identification on the secondary gravity value data to obtain third gravity value normal data, error data, jump data and continuous drop-grid data, then outputting the third gravity value normal data, error data, jump data and continuous drop-grid data together to obtain tertiary gravity value data, then performing correction processing on the error data, jump data and continuous drop-grid data in the tertiary gravity value data to obtain gravity value correction data; Step 3: First, perform theoretical solid tide correction on the gravity value correction data, and then obtain gravity solid tide preprocessing data, then perform tidal correction on the gravity solid tide preprocessing data, and then obtain gravity tidal correction data, then perform air pressure correction on the gravity tidal correction data, and then obtain gravity air pressure correction data, then perform ocean tide correction on the gravity air pressure correction data, and then obtain gravity ocean tide correction data, then perform extreme tide correction on the gravity ocean tide correction data, and then obtain gravity extreme tide correction data, and then obtain a high-precision gravity field model based on the gravity extreme tide correction data, and this method ends.

[0043] Preferably, based on the high-precision gravity field model, a national spatial change distribution map of gravity tidal factors, a national spatial change distribution map of gravity non-tidal factors, a monthly tidal change time series map, a national spatial change cloud map of gravity field and a national spatial change distribution map of background noise can be generated.

[0044] Example 2: The basic content is the same as Example 1, except that: See Figure 1 — Figure 3In the second step, the error data identification is performed by using a derivative method and a probability statistics method. In the second step, the jump data identification is performed by using a derivative method and a threshold method. In the second step, the continuous drop data identification is performed by using a derivative method. In the second step, the correction processing is performed by first using the error data and the difference between the data before the error data and the data after the error data as a primary drop correction value, and then correcting the error data using the primary drop correction value; then using the jump data and the difference between the data before the jump data and the data after the jump data as a secondary drop correction value, and then correcting the jump data using the secondary drop correction value; then using the continuous drop data and the difference between the data before the continuous drop data and the data after the continuous drop data as a tertiary drop correction value, and then correcting the continuous drop data using the tertiary drop correction value.

[0045] When applied, in the second step, the gravity value correction data is firstly subjected to error data identification using the derivative method and the probability statistics method to obtain the first gravity value normal data and error data, and then the primary gravity value data is obtained after output, and the primary gravity value data is then subjected to the derivative method and the threshold method to perform jump data identification to obtain the second gravity value normal data, jump data and error data, and then the secondary gravity value data is then obtained after output, and the secondary gravity value data is then subjected to the derivative method to perform continuous drop data identification to obtain triple gravity value normal data, error data, jump data and continuous drop data, and then the tertiary gravity value data is obtained after output, and the error data in the tertiary gravity value data is then corrected, and the error data, the data before the error data and the data after the error data are combined. The difference between the two values is used as a first discontinuous grid drop correction value, and then the erroneous data is corrected using the first discontinuous grid drop correction value, and then the jump data in the three gravity value data is corrected, and the difference between the jump data, the data before the jump data and the data after the jump data is used as a second discontinuous grid drop correction value, and then the jump data is corrected using the second discontinuous grid drop correction value, and then the continuous grid drop data in the three gravity value data is corrected, and the difference between the continuous grid drop data, the data before the continuous grid drop data and the data after the continuous grid drop data is used as a third discontinuous grid drop correction value, and then the continuous grid drop correction value is used to correct the continuous grid drop data, and then the gravity value correction data is obtained; the erroneous data is the data whose derivative is 0.

[0046] Example 3: The basic content is the same as Example 1, except that: See Figure 1 — Figure 2In the first step, the downsampling process involves first downsampling the gravity observation data using an IIR filter to obtain intermediate data, then performing a differential calculation on the intermediate data to obtain low-sampling rate observation data. In the first step, the gravimeter grid value coefficient includes an additive constant correction value and a nonlinear zero drift correction value.

[0047] During application, after obtaining gravity observation data from multiple stations, the gravity observation data are downsampled using the IIR filter through filtering technology. The downsampling algorithm adopts segmented sampling, including four segment lengths, namely within one minute, within five minutes, within one hour, and outside one hour, and then the intermediate data is obtained; the intermediate data is then differentially calculated to obtain low-sampling rate observation data, and then the low-sampling rate observation data is converted into gravity value observation data based on the gravimeter grid value coefficient. In this process, the low-sampling rate observation data is currently processed and analyzed in units of months. The low-sampling rate observation data includes multiple small segments with time intervals. In order to ensure the continuity of the data, the small segments need to be connected, and all the additive constant correction numbers before the time of the small segment data to be connected are accumulated to obtain the additive constant correction value of the current month. Then the difference between the last and first data of this month and last month is calculated. If it is greater than 5 microgal, then this data is also used as the additive constant correction number. The gravimeter grid coefficient also includes a nonlinear zero drift correction value. That is, when the stress-strain law of the observation system of the gravimeter at the station is no longer linear due to factors such as power supply and human interference, a relaxation process will occur. Therefore, a zero drift correction model is used to simulate the nonlinear zero drift in the gravimeter in the gravity residual time series, and then the relaxation time is obtained. The relaxation process is then corrected based on the relaxation time. In most cases, the zero drift correction model can be used continuously after modifying the corresponding time parameters. The process of correcting the gravity observation data for theoretical earth tides is as follows: first, the geographic latitude in the gravity observation data is converted to geocentric latitude, and then the Julian century number T is calculated. Then, the Julian century number T is used to obtain the lunar mean ecliptic longitude S, the lunar deep node ecliptic longitude N, the lunar perigee ecliptic longitude P, the solar mean ecliptic longitude h, the solar perigee ecliptic longitude Ps, and the ecliptic obliquity sigma. The above parameters are then substituted into the earth tide formula for calculation, and the calculation results are used to correct the gravity observation data.

[0048] Example 4: The basic content is the same as Example 1, except that: See Figure 1 — Figure 4In the third step, the tidal correction is performed by first using a precise tidal model to calculate the theoretical solid tide for tidal correction. In the third step, the pressure correction is performed by using co-located pressure observation data and pressure admittance values. In the third step, the ocean tide correction is performed by using the ocean tide load influence of the forward modeling station using the Nao99b and Nao99bj global and regional ocean tide models. In the third step, the extreme tide correction is performed by using the extreme tide correction data of the polar motion parameter calculation station for extreme tide correction.

[0049] When applied, in the third step, after obtaining the gravity solid tide preprocessing data, the gravity solid tide preprocessing data is first used to calculate the theoretical solid tide using a precise tidal model to perform tidal correction, and then the gravity tidal correction data is obtained, and then the gravity tidal correction data is used to perform pressure correction using the same-site air pressure observation data and air pressure admittance value, and then the gravity pressure correction data is obtained, and then the gravity pressure correction data is used to perform tide correction using the ocean tide load influence of the forward simulation station using the Nao99b and Nao99bj global and regional ocean tide models, and then the gravity ocean tide correction data is obtained, and then the gravity ocean tide correction data is used to calculate the extreme tide correction data of the station using the polar shift parameters to perform extreme tide correction, and then the gravity extreme tide correction data is obtained, and then a high-precision gravity field model is obtained based on the gravity extreme tide correction data.

[0050] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed in the present invention should be included in the protection scope recorded in the claims.

Claims

1. A method for establishing a high-precision gravity field model, characterized by: The method comprises the following steps: The first step is to obtain gravity observation data from multiple stations, downsample the gravity observation data, and obtain low-sampling rate observation data; then convert the low-sampling rate observation data into gravity value observation data based on the gravimeter grid value coefficient, and then perform theoretical solid tide correction on the gravity value observation data to obtain gravity value correction data; Step 2: firstly, performing error data identification on the gravity value correction data to obtain first gravity value normal data and error data, then outputting the first gravity value normal data and error data together to obtain primary gravity value data, then performing jump data identification on the primary gravity value data to obtain second gravity value normal data, jump data and error data, then outputting the second gravity value normal data, jump data and error data together to obtain secondary gravity value data, then performing continuous drop-grid data identification on the secondary gravity value data to obtain third gravity value normal data, error data, jump data and continuous drop-grid data, then outputting the third gravity value normal data, error data, jump data and continuous drop-grid data together to obtain tertiary gravity value data, then performing correction processing on the error data, jump data and continuous drop-grid data in the tertiary gravity value data to obtain gravity value correction data; Step 3: First, perform theoretical solid tide correction on the gravity value correction data, and then obtain gravity solid tide preprocessing data, then perform tidal correction on the gravity solid tide preprocessing data, and then obtain gravity tidal correction data, then perform air pressure correction on the gravity tidal correction data, and then obtain gravity air pressure correction data, then perform ocean tide correction on the gravity air pressure correction data, and then obtain gravity ocean tide correction data, then perform extreme tide correction on the gravity ocean tide correction data, and then obtain gravity extreme tide correction data, and then obtain a high-precision gravity field model based on the gravity extreme tide correction data, and this method ends.

2. The method for establishing a high-precision gravity field model according to claim 1, wherein: In the second step, the erroneous data identification is performed by using a derivative method or a probability statistics method.

3. The method for establishing a high-precision gravity field model according to claim 2, wherein: In the second step, the sudden jump data is identified by using a derivative method or a threshold method.

4. The method for establishing a high-precision gravity field model according to claim 3, wherein: In the second step, the continuous frame-dropping data identification is performed by using a derivative method.

5. The method for establishing a high-precision gravity field model according to claim 4, characterized in that: In the second step, the correction process is to first use the difference between the erroneous data, the data before the erroneous data and the data after the erroneous data as a one-time discontinuous grid correction value, and then use the one-time discontinuous grid correction value to correct the erroneous data; Then the difference between the sudden jump data, the data before the sudden jump data and the data after the sudden jump data is used as the secondary discontinuous grid correction value, and the sudden jump data is corrected using the secondary discontinuous grid correction value; Then the difference between the continuous dropped frame data, the data before the continuous dropped frame data and the data after the continuous dropped frame data is used as the three-time intermittent dropped frame correction value, and then the three-time intermittent dropped frame correction value is used to correct the continuous dropped frame data.

6. The method for establishing a high-precision gravity field model according to claim 1, wherein: In the first step, the downsampling process is to first downsample the gravity observation data using an IIR filter to obtain intermediate data, then perform differential calculation on the intermediate data, and then obtain low-sampling rate observation data; In the first step, the gravimeter grid value coefficient includes an additive constant correction value and a nonlinear zero drift correction value.

7. The method for establishing a high-precision gravity field model according to claim 1, wherein: In the third step, the tidal correction is performed by first calculating the theoretical solid tide using a precise tidal model.

8. The method for establishing a high-precision gravity field model according to claim 7, characterized in that: In the third step, the air pressure correction is performed by using the same-site air pressure observation data and the air pressure admittance value.

9. A method for establishing a high-precision gravity field model according to claim 8, characterized in that: In the third step, the ocean tide correction is performed by using the Nao99b and Nao99bj global and regional ocean tide models to forward simulate the ocean tide load effects of the stations.

10. A high-precision gravity field model establishment method according to claim 9, characterized in that: In the third step, the polar tide correction is performed by using the polar motion parameters to calculate the polar tide correction data of the station.

Images