Gravity inversion precision evaluation system and method considering ship measurement self noise

Abstract

The invention provides a gravity inversion precision evaluation system and method considering ship measurement noise, and the system comprises a ship measurement gravity data verification module which is used for verifying a height measurement gravity inversion product through employing the ship measurement gravity data after refining the ship measurement gravity data, obtaining the ship measurement verification precision of the height measurement gravity inversion product, and obtaining the ship measurement verification precision of the height measurement gravity inversion product; verifying the gravitational field model by adopting the ship measurement gravity data to obtain the ship measurement verification precision of the gravitational field model; the global gravitational field model comparison module is used for intercepting a global gravitational field model for comparison to obtain gravitational field model comparison precision of the height measurement gravity inversion product; and the gravity inversion precision evaluation module is used for jointly resolving self noise of the ship test verification data and deducting the self noise of the ship test to obtain accurate satellite altimetry gravity inversion precision. The method has the advantages that the influence of the noise of the ship measurement gravity data on the height measurement gravity inversion precision can be effectively removed, and the accurate height measurement gravity inversion precision can be evaluated.

Description

Technical Field

[0001] This application belongs to the field of marine remote sensing mapping, and particularly relates to a gravity inversion accuracy evaluation system and method considering the self-noise of shipborne measurements. Background Art

[0002] A radar altimeter is an important active microwave remote sensor carried on marine remote sensing satellites. It obtains marine observation data such as sea surface height (SSH), significant wave height, and wind speed by transmitting radar pulse signals to the sea surface and receiving echo signals. Extracting gravity-related parameters such as the marine geoid and vertical deflection from satellite altimeter SSH data can further invert the marine gravity field. Compared with traditional shipborne gravity measurement methods, satellite altimeters can complete the workload of the past century in just a few months, with unparalleled superiority. Compared with gravity satellite observations, satellite altimeters can obtain the short-wave marine gravity field globally and are currently the only means to obtain the short-wave gravity field with global coverage. Therefore, satellite altimeters are currently the main means to obtain a high-precision global marine gravity field.

[0003] Currently, the main methods for evaluating the accuracy of satellite altimeter-inverted marine gravity field products are shipborne gravity data verification and comparison with global gravity field models. Shipborne gravity data verification has become the most commonly used method for evaluating the accuracy of satellite altimetry gravity inversion because it uses external measured data. The National Centers for Environmental Information (NCEI) of the National Oceanic and Atmospheric Administration (NOAA) of the United States provides shipborne gravity data globally, which is a good data source for verifying the gravity inversion accuracy of satellite altimeters. To avoid the influence of noise and errors in shipborne gravity data on the evaluation accuracy, these shipborne gravity data from different years, different ships, different measurement devices, etc. are usually preprocessed before use to improve the accuracy, but the shipborne data itself still inevitably has noise.

[0004] In the early stage when satellite altimetry gravity inversion was not very accurate, the noise of shipborne gravity data itself was much smaller than the noise of the inverted gravity field, and this influence could be ignored. However, with the gradual improvement of satellite altimeter data accuracy and the gradual refinement of the inversion process, the accuracy of the altimetry marine gravity field has also been greatly improved, gradually approaching 1 milligal from dozens of milligals, while the noise of shipborne gravity data itself is also at the milligal level. Therefore, this method of shipborne gravity data verification that ignores the self-noise of shipborne measurements is no longer suitable for evaluating the current accuracy of satellite altimetry gravity inversion. Summary of the Invention

[0005] The purpose of this application is to overcome the defect that the existing accuracy evaluation method of shipborne gravity data verification ignores the self-noise of shipborne measurements and is difficult to evaluate the accurate satellite altimetry gravity inversion accuracy.

[0006] To achieve the above object, the present application proposes a gravity inversion accuracy evaluation system that takes into account the self-noise of shipborne measurements. The system includes:

[0007] A shipborne gravity data verification module, which is used to refine the shipborne gravity data and then use the shipborne gravity data to verify the altimetry gravity inversion product, calculate the root mean square error between the two, and obtain the shipborne verification accuracy of the altimetry gravity inversion product. At the same time, use the shipborne gravity data to verify the gravity field model and obtain the shipborne verification accuracy of the gravity field model;

[0008] A global gravity field model comparison module, which is used to intercept the global gravity field model according to the longitude and latitude range of the altimetry inversion sea area for comparison, and calculate the root mean square error between the gravity field model and the altimetry gravity inversion product in combination with the land-sea mask information, and obtain the gravity field model comparison accuracy of the altimetry gravity inversion product;

[0009] A gravity inversion accuracy evaluation module, which is used to jointly calculate the gravity field model comparison accuracy, shipborne verification accuracy of the altimetry gravity inversion product, and shipborne verification accuracy of the gravity field model, calculate the self-noise of the shipborne verification data, and then deduct the shipborne self-noise to obtain the accurate satellite altimetry gravity inversion accuracy.

[0010] As an improvement of the above system, the processing process of the shipborne gravity data verification module includes:

[0011] Step A1: Perform long-wave error correction and datum unification according to the sounding line time, longitude and latitude, and the residual value range information of the model gravity to suppress noise, and obtain refined shipborne gravity data;

[0012] Step A2: Interpolate the altimetry gravity inversion product to the corresponding position of the shipborne gravity using the longitude and latitude information, calculate the root mean square error between the two, and obtain the shipborne verification accuracy of the altimetry gravity inversion product :

[0013]

[0014] where, is the number of points of the shipborne verification data; is the gravity value corresponding to the th point of the shipborne verification data; is the gravity value interpolated from the th point of the altimetry gravity inversion product.

[0015] Step A3: Interpolate the gravity field model to the corresponding position of the shipborne gravity using the longitude and latitude information, calculate the root mean square error between the two, and obtain the shipborne verification accuracy of the gravity field model :

[0016]

[0017] Among them, is the gravity value obtained by interpolating the th point of the gravity field model.

[0018] As an improvement of the above system, the processing process of the global gravity field model comparison module includes:

[0019] Step B1: Intercept the gravity field model of the altimetry inversion sea area from the global gravity field model according to the longitude and latitude range of the altimetry gravity inversion product for comparison;

[0020] Step B2: Use the longitude and latitude information to interpolate the altimetry gravity inversion product to the corresponding position of the altimetry inversion sea area gravity field model, and combine the land-sea mask information to calculate the root mean square error between the two, and obtain the comparison accuracy between the altimetry gravity inversion product and the gravity field model :

[0021]

[0022] Among them, is the number of points of the altimetry inversion sea area gravity field model; is the gravity value corresponding to the th point of the inversion sea area gravity field model; is the gravity value obtained by interpolating the th point of the altimetry gravity inversion product; is the land-sea mask value of the th point.

[0023] As an improvement of the above system, the processing process of the gravity inversion accuracy evaluation module includes:

[0024] Step C1: Jointly solve the comparison accuracy of the gravity field model of the altimetry gravity inversion product , the ship measurement verification accuracy and the ship measurement verification accuracy of the gravity field model to calculate the self-noise of the ship measurement verification data;

[0025]

[0026] Step C2: Deduct the ship measurement self-noise from the ship measurement verification accuracy of the altimetry gravity inversion product to obtain the accurate satellite altimetry gravity inversion accuracy :

[0027] .

[0028] This application also provides a gravity inversion accuracy evaluation method considering the ship measurement self-noise, which is implemented based on the above system and includes:

[0029] Step 1: Perform long-wave error correction and datum unification processing on the shipborne gravity data to suppress noise, and obtain the refined shipborne gravity data.

[0030] Step 2: Interpolate the altimetry gravity to the corresponding position of the shipborne gravity using the latitude and longitude information, calculate the root mean square error between the altimetry gravity and the shipborne gravity, and obtain the shipborne verification accuracy of the altimetry gravity inversion product. ;

[0031] Step 3: Interpolate the gravity field model to the corresponding position of the shipborne gravity using the latitude and longitude information, calculate the root mean square error between the gravity field model and the shipborne gravity, and obtain the shipborne verification accuracy of the gravity field model. ;

[0032] Step 4: Intercept the gravity field model of the altimetry inversion sea area from the global gravity field model according to the latitude and longitude range of the altimetry gravity inversion product for comparison.

[0033] Step 5: Interpolate the altimetry gravity inversion product to the corresponding position of the altimetry inversion sea area gravity field model using the latitude and longitude information, and calculate the root mean square error between the two in combination with the land-sea mask information to obtain the comparison accuracy between the altimetry gravity inversion product and the gravity field model. ;

[0034] Step 6: Jointly solve the comparison accuracy of the gravity field model of the altimetry gravity inversion product, the shipborne verification accuracy, and the shipborne verification accuracy of the gravity field model, and calculate the self-noise of the shipborne verification data. ;

[0035] Step 7: Deduct the shipborne self-noise from the shipborne verification accuracy of the altimetry gravity inversion product to obtain the accurate satellite altimetry gravity inversion accuracy. .

[0036] Compared with the prior art, the advantages of this application are as follows:

[0037] 1. This application establishes a satellite altimetry gravity inversion accuracy evaluation system that takes into account the shipborne self-noise.

[0038] 2. The satellite altimetry gravity inversion accuracy evaluation method proposed in this application can effectively remove the influence of the self-noise of the shipborne gravity data on the altimetry gravity inversion accuracy and evaluate the accurate altimetry gravity inversion accuracy through the cross-verification of the shipborne gravity data, the global gravity field model, and the altimetry gravity inversion product. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Shown is the structural diagram of the satellite altimetry gravity inversion accuracy evaluation system that takes into account the shipborne self-noise;

[0040] Figure 2 The figure shows a flow chart of a method for evaluating the accuracy of satellite altimetry gravity inversion considering the self-noise of shipborne measurements. Specific implementation manners

[0041] The technical solution of the present application will be described in detail below with reference to the accompanying drawings.

[0042] The system and method for evaluating the accuracy of satellite altimetry gravity inversion considering the self-noise of shipborne measurements proposed in the present application are applicable not only to radar altimeters but also to laser altimeters. By cross-verifying shipborne gravity data, global gravity field models, and altimetry gravity inversion products, the influence of the self-noise of shipborne gravity data on the evaluation of the accuracy of altimetry gravity inversion can be effectively removed, and accurate altimetry gravity inversion accuracy can be obtained.

[0043] Example 1

[0044] As Figure 1 shown, the present application proposes a system for evaluating the accuracy of satellite altimetry gravity inversion considering the self-noise of shipborne measurements, including a verification module for shipborne gravity data, a comparison module for global gravity field models, and an evaluation module for gravity inversion accuracy.

[0045] The design of each module is as follows:

[0046] 1. Verification module for shipborne gravity data: After refining the shipborne gravity data, it is used to verify the altimetry gravity inversion product with the shipborne gravity data, calculate the root mean square error between the two, and obtain the shipborne verification accuracy of the altimetry gravity inversion product. At the same time, the shipborne gravity data is used to verify the gravity field model to obtain the shipborne verification accuracy of the gravity field model;

[0047] The processing process of the verification module for shipborne gravity data includes:

[0048] Step 1: Refining the shipborne gravity data; performing long-wave error correction and datum unification based on information such as the survey line time, longitude and latitude, and the residual value range from the model gravity to suppress noise, and obtaining the refined shipborne gravity data;

[0049] Step 2: Calculating the altimetry-shipborne verification accuracy; interpolating the altimetry gravity inversion product to the corresponding position of the shipborne gravity using the longitude and latitude information, and calculating the root mean square error between the two to obtain the shipborne verification accuracy of the altimetry gravity inversion product:

[0050]

[0051] where, is the number of points of the shipborne verification data; is the gravity value corresponding to the th point of the shipborne verification data; is the gravity value corresponding to the Gravity values obtained by point interpolation.

[0052] Step 3: Calculation of the accuracy of model - ship measurement verification; Interpolate the gravity field model to the corresponding positions of the ship - measured gravity using the longitude and latitude information, calculate the root - mean - square error between the two, and obtain the ship - measurement verification accuracy of the gravity field model:

[0053]

[0054] where is the number of points of the ship - measurement verification data; is the gravity value corresponding to the - th point of the ship - measurement verification data; is the gravity value obtained by interpolating the - th point of the gravity field model.

[0055] 2. Global gravity field model comparison module: Used to intercept the global gravity field model according to the longitude and latitude range of the altimetry - derived sea area for comparison, and calculate the root - mean - square error between the gravity field model and the altimetry - derived gravity inversion product in combination with the land - sea mask information to obtain the comparison accuracy of the gravity field model of the altimetry - derived gravity inversion product;

[0056] The processing process of the global gravity field model comparison module includes:

[0057] Step 1: Interception of the model of the altimetry - derived sea area; Intercept the gravity field model of the altimetry - derived sea area from the global gravity field model according to the longitude and latitude range of the altimetry - derived gravity inversion product for comparison;

[0058] Step 2: Calculation of the comparison accuracy of altimetry - model; Interpolate the altimetry - derived gravity inversion product to the corresponding positions of the gravity field model of the altimetry - derived sea area using the longitude and latitude information, and calculate the root - mean - square error between the two in combination with the land - sea mask information to obtain the comparison accuracy between the altimetry - derived gravity inversion product and the gravity field model:

[0059]

[0060] where is the number of points of the gravity field model of the altimetry - derived sea area; is the gravity value corresponding to the - th point of the gravity field model of the inversion sea area; is the gravity value obtained by interpolating the - th point of the altimetry - derived gravity inversion product; is the land - sea mask value of the - th point, 0 for land and 1 for sea.

[0061] 3. Gravity Inversion Accuracy Evaluation Module: It is used to calculate by combining the comparison accuracy of the gravity field model of the altimetry gravity inversion product, the shipborne measurement verification accuracy, and the shipborne measurement verification accuracy of the gravity field model, calculate the self-noise of the shipborne measurement verification data, and then deduct the shipborne self-noise to obtain the accurate satellite altimetry gravity inversion accuracy;

[0062] The processing process of the gravity inversion accuracy evaluation module includes:

[0063] Step 1: Cross-validation combined calculation; Calculate by combining the comparison accuracy of the gravity field model of the altimetry gravity inversion product, the shipborne measurement verification accuracy, and the shipborne measurement verification accuracy of the gravity field model, and calculate the self-noise of the shipborne measurement verification data ;

[0064]

[0065] Step 2: Deduction of shipborne self-noise; Deduct the shipborne self-noise from the shipborne measurement verification accuracy of the altimetry gravity inversion product to obtain the accurate satellite altimetry gravity inversion accuracy :

[0066]

[0067] Embodiment 2

[0068] As Figure 2 shown, the present application also proposes a method for evaluating the satellite altimetry gravity inversion accuracy considering the shipborne self-noise, which is implemented based on the above system and includes:

[0069] Step 1) Perform long-wave error correction and datum unification processing on the shipborne gravity data to suppress noise and obtain refined shipborne gravity data;

[0070] Step 2) Interpolate the altimetry gravity to the corresponding position of the shipborne gravity using the longitude and latitude information, calculate the root mean square error between the altimetry gravity and the shipborne gravity, and obtain the shipborne measurement verification accuracy of the altimetry gravity inversion product ;

[0071] Step 3) Interpolate the gravity field model to the corresponding position of the shipborne gravity using the longitude and latitude information, calculate the root mean square error between the gravity field model and the shipborne gravity, and obtain the shipborne measurement verification accuracy of the gravity field model ;

[0072] Step 4) Intercept the gravity field model of the altimetry inversion sea area from the global gravity field model according to the longitude and latitude range of the altimetry gravity inversion product for comparison;

[0073] Step 5) Interpolate the altimetry gravity inversion product to the corresponding position of the altimetry inversion sea area gravity field model using the longitude and latitude information, and calculate the root mean square error between the two in combination with the land-sea mask information to obtain the comparison accuracy between the altimetry gravity inversion product and the gravity field model. ;

[0074] Step 6) Solve by combining the comparison accuracy of the gravity field model of the altimetry gravity inversion product, the shipborne measurement verification accuracy of the altimetry gravity inversion product, and the shipborne measurement verification accuracy of the gravity field model, and calculate the self-noise of the shipborne measurement verification data. ;

[0075] Step 7) Deduct the shipborne measurement self-noise from the shipborne measurement verification accuracy of the altimetry gravity inversion product to obtain the accurate satellite altimetry gravity inversion accuracy. 。

[0076] The present application can also provide a computer device, including: at least one processor, a memory, at least one network interface, and a user interface. Each component in the device is coupled together through a bus system. It can be understood that the bus system is used to realize the connection and communication between these components. In addition to the data bus, the bus system also includes a power bus, a control bus, and a status signal bus.

[0077] Among them, the user interface may include a display, a keyboard, or a pointing device. For example, a mouse, a trackball, a touchpad, or a touch screen, etc.

[0078] It can be understood that the memory in the disclosed embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DRRAM). The memories described herein are intended to include, but are not limited to, these and any other suitable types of memories.

[0079] In some embodiments, the memory stores the following elements, executable modules, or data structures, or subsets or supersets thereof: an operating system and application programs.

[0080] Among them, the operating system includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., and is used to implement various basic services and handle hardware-based tasks. The application programs include various application programs, such as a media player and a browser, etc., and are used to implement various application services. The program for implementing the method of the disclosed embodiments of the present application can be included in the application programs.

[0081] In the above embodiments, by calling the programs or instructions stored in the memory, specifically, the programs or instructions stored in the application programs, the processor is configured to:

[0082] Execute the steps of the above method.

[0083] The above method can be applied to or implemented by a processor. The processor may be an integrated circuit chip with the ability to process signals. During implementation, the steps of the above method can be completed by the integrated logic circuit of the hardware in the processor or instructions in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed above. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. Combining the steps of the above-disclosed method can be directly embodied as being executed and completed by a hardware decoding processor, or by a combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, etc. This storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0084] It can be understood that these embodiments described in the present application can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in the present application, or a combination thereof.

[0085] For software implementation, the technology of the present application can be implemented by executing the functional modules of the present application (such as procedures, functions, etc.). The software code can be stored in the memory and executed by the processor. The memory can be implemented inside or outside the processor.

[0086] The present application may also provide a non-volatile storage medium for storing a computer program. When the computer program is executed by a processor, each step in the above method embodiments can be implemented.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present application does not depart from the spirit and scope of the technical solutions of the present application, and they should all be covered within the scope of the claims of the present application.

Claims

1. A gravity inversion accuracy evaluation system considering the self-noise of shipborne measurements, characterized in that The system includes: A shipborne gravity data verification module, which is used to refine the shipborne gravity data, then use the shipborne gravity data to verify the altimetry gravity inversion product, calculate the root mean square error between the two, and obtain the shipborne verification accuracy of the altimetry gravity inversion product. At the same time, use the shipborne gravity data to verify the gravity field model and obtain the shipborne verification accuracy of the gravity field model; A global gravity field model comparison module, which is used to intercept the global gravity field model according to the longitude and latitude range of the altimetry inversion sea area for comparison, and calculate the root mean square error between the gravity field model and the altimetry gravity inversion product in combination with the land-sea mask information, so as to obtain the gravity field model comparison accuracy of the altimetry gravity inversion product; and A gravity inversion accuracy evaluation module, which is used to jointly calculate the gravity field model comparison accuracy, shipborne verification accuracy of the altimetry gravity inversion product and shipborne verification accuracy of the gravity field model, calculate the self-noise of the shipborne verification data, and then deduct the shipborne self-noise to obtain the accurate satellite altimetry gravity inversion accuracy.

2. The gravity inversion accuracy evaluation system considering the self-noise of ship measurement according to claim 1, characterized in that The processing process of the shipborne gravity data verification module includes: Step A1: Perform long-wave error correction and datum unification according to the sounding line time, longitude and latitude, and the residual value range information of the model gravity to suppress noise, and obtain the refined shipborne gravity data; Step A2: Interpolate the altimetry gravity inversion product to the corresponding position of the shipboard gravity using the latitude and longitude information, calculate the root mean square error between the two, and obtain the shipboard verification accuracy of the altimetry gravity inversion product : ； Among them, is the number of points of ship measurement verification data; is the gravity value corresponding to the -th point of ship measurement verification data; is the gravity value obtained by interpolation of the -th point of the altimetry gravity inversion product; Step A3: Interpolate the gravity field model to the corresponding positions of the shipboard gravity measurements using the latitude and longitude information, calculate the root mean square error between the two, and obtain the shipboard verification accuracy of the gravity field model : ； Among them, is the gravity value obtained by interpolating the point of the gravity field model.

3. The gravity inversion accuracy evaluation system considering the ship's own noise according to claim 1, characterized in that The processing process of the global gravity field model comparison module includes: Step B1: Intercept the gravity field model of the altimetry inversion sea area from the global gravity field model according to the longitude and latitude range of the altimetry gravity inversion product for comparison; Step B2: Interpolate the altimetry gravity inversion product to the corresponding position of the altimetry inversion sea area gravity field model using the latitude and longitude information, and calculate the root mean square error between the two in combination with the land-sea mask information to obtain the comparison accuracy between the altimetry gravity inversion product and the gravity field model : ； Among them, is the number of points for the altimetry-inverted ocean gravity field model; is the gravity value corresponding to the -th point of the inverted ocean gravity field model; is the gravity value interpolated from the -th point of the altimetry gravity inversion product; is the land-sea mask value of the -th point.

4. The gravity inversion accuracy evaluation system considering the ship's own noise according to claim 1, characterized in that The processing process of the gravity inversion accuracy evaluation module includes: Step C1: Compare the accuracy of the gravity field models of the combined altimetry gravity inversion products , the accuracy of shipborne measurement verification and the accuracy of shipborne measurement verification of the gravity field model Perform calculations to calculate the self-noise of the shipborne measurement verification data ; ； Step C2: Deduct the ship measurement's own noise from the ship measurement verification accuracy of the altimetry gravity inversion product to obtain the accurate satellite altimetry gravity inversion accuracy : 。 5. A method for evaluating the gravity inversion accuracy considering the shipborne self-noise, which is implemented based on the system described in any one of claims 1-4, and includes: Step 1: Perform long-wave error correction and datum unification processing on the shipborne gravity data to suppress noise, and obtain the refined shipborne gravity data; Step 2: Interpolate the altimetric gravity to the corresponding positions of the shipborne gravity using the latitude and longitude information, calculate the root mean square error between the altimetric gravity and the shipborne gravity, and obtain the shipborne verification accuracy of the altimetric gravity inversion product ; Step 3: Interpolate the gravity field model to the corresponding positions of the shipborne gravity using the latitude and longitude information, calculate the root mean square error between the gravity field model and the shipborne gravity, and obtain the shipborne verification accuracy of the gravity field model ; Step 4: Intercept the gravity field model of the altimetry inversion sea area from the global gravity field model according to the longitude and latitude range of the altimetry gravity inversion product for comparison; Step 5: Interpolate the altimetry gravity inversion product to the corresponding position of the altimetry inversion sea area gravity field model using the latitude and longitude information, and calculate the root mean square error between the two by combining the land-sea mask information to obtain the comparison accuracy between the altimetry gravity inversion product and the gravity field model ; Step 6: Calculate by comparing the accuracy of the gravity field model of the combined altimetry gravity inversion product, the shipborne measurement verification accuracy, and the shipborne measurement verification accuracy of the gravity field model, and calculate the self-noise of the shipborne measurement verification data ; Step 7: Deduct the ship measurement's own noise from the ship measurement verification accuracy of the altimetry gravity inversion product to obtain the accurate satellite altimetry gravity inversion accuracy .

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