A method and system for correcting elevation deviation of gravity field model

Abstract

The present invention relates to the field of geodesy, and in particular to a method and system for correcting the elevation deviation of a gravity field model. The solution of the present application calculates the elevation anomaly of a leveling point by acquiring GNSS / leveling data of a local area, and then calculates the disturbance position of the leveling point; substitutes the coordinate parameters of the leveling point into a preset gravity field model to calculate the model disturbance position of the leveling point, and then calculates the disturbance position deviation of the gravity field model on the earth's surface according to the disturbance position and the model disturbance position; calculates the disturbance position deviation of the internal sphere according to the integral relationship between the disturbance position deviation and the disturbance position deviation of the internal sphere, corrects the model disturbance position of the internal sphere by the disturbance position deviation of the internal sphere, obtains the corrected internal sphere disturbance position, and then calculates the gravity field model by the corrected internal sphere disturbance position to obtain a high-resolution gravity field model. By adopting the solution of the present application, the local elevation deviation of the model can be effectively corrected, and high-precision calculation of local elevation anomalies can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of geodetic technology, and in particular to a method and system for correcting elevation deviation of a gravity field model. Background Art

[0002] The gravity field is the most basic and direct physical quantity that reflects the density changes of the earth's medium and its dynamic characteristics under various environments (solid earth tides, internal heat flow, mass exchange between solids and liquids, surface loads, and earthquake tectonic movements, etc.). The gravity field and its changes reflect the density distribution and motion state of materials on the earth's surface and interior. Based on the spatiotemporal changes of the gravity field, the material migration and exchange process of the earth system can be deduced and monitored. The higher the spatiotemporal resolution of the gravity field, the more time-varying information of the earth's material system it contains. Therefore, high-resolution time-varying information of the earth's gravity field is of great significance for the study of geodynamic processes and practical applications.

[0003] The high-resolution gravity field model can be used to calculate parameters such as elevation anomalies. However, the elevation benchmarks of the multi-source gravity data currently used in building the model are inconsistent, resulting in deviations between the gravity field model and the elevation benchmark of the local area. Therefore, it is necessary to correct the elevation benchmark of the gravity field model to calculate high-precision elevation anomalies. Summary of the invention Summary of the invention

[0005] The present invention provides a method and system for correcting elevation deviation of a gravity field model, which effectively solves the problem of deviation between the existing gravity field model and the elevation benchmark of a local area.

[0006] According to the first aspect, an embodiment provides a method for correcting elevation deviation of a gravity field model, comprising:

[0007] Acquire GNSS / leveling data of a local area; the GNSS / leveling data includes geodetic height and normal height of a leveling point in the local area; the leveling point in the local area is on the surface of the earth;

[0008] Determine the elevation anomaly of the leveling point according to the GNSS / leveling data;

[0009] Calculating the disturbance position of the leveling point according to the elevation anomaly and the normal gravity of the projection point of the leveling point on the topographic surface;

[0010] Acquiring coordinate parameters of the leveling point, and calculating the model disturbance position of the leveling point according to the coordinate parameters and a preset gravity field model;

[0011] Calculating the disturbance position deviation of the gravity field model on the earth's surface according to the disturbance position and the model disturbance position;

[0012] Selecting an internal spherical surface according to GNSS / leveling data of a local area, and determining the perturbed potential deviation of the internal spherical surface according to an integral relationship between the perturbed potential deviation of the earth's surface and the perturbed potential deviation of the internal spherical surface;

[0013] Calculating the model disturbance position of the inner spherical surface according to the coordinate parameters of the inner spherical surface and the gravity field model;

[0014] Correcting the model disturbance position of the inner spherical surface by the disturbance position deviation of the inner spherical surface to obtain the corrected disturbance position of the inner spherical surface;

[0015] The corrected high-resolution gravity field model is obtained by calculating the corrected internal spherical disturbance potential.

[0016] In one implementation, the calculation formula for calculating the disturbance position of the leveling point position is as follows:

[0017] ;

[0018] In the formula, express i The disturbance position of the point, Represents the Earth's surface i The elevation anomaly of the point, It represents the normal gravity of the projection point of the leveling point on the topographic surface.

[0019] In one implementation, the calculation formula for calculating the model disturbance position of the leveling point position is as follows:

[0020] ;

[0021] In the formula, express i The model perturbation position of the point, G is the gravitational constant, M is the mass of the Earth, r for i The distance from a point to the center of the earth, and are the coefficients of the gravity field model, is the Legendre function, n is the order, m is the number of times, is the geocentric longitude, is the geocentric latitude, a is the semi-major axis of the reference ellipsoid.

[0022] In one implementation, determining the disturbance potential deviation of the inner spherical surface according to the integral relationship between the disturbance potential deviation of the earth surface and the disturbance potential deviation of the inner spherical surface includes:

[0023] According to Poisson integral, the integral relationship between the disturbance potential deviation on the earth's surface and the disturbance potential deviation on the internal spherical surface is established;

[0024] According to the discrete data of the selected inner sphere, the integral relation is discretized to obtain a discretized relation;

[0025] The perturbed position deviation of the earth surface is taken as the initial value of the perturbed position deviation of the inner spherical surface, and the discretized relational expression is iteratively solved to obtain the perturbed position deviation of the inner spherical surface.

[0026] In one implementation, the integral relationship is expressed as:

[0027] ;

[0028] In the formula, is the disturbance potential deviation of the earth's surface, is the perturbation deviation of the inner sphere, is the geocentric longitude of the inner sphere, is the geocentric latitude of the inner sphere, R is the inner spherical radius, l For the inner sphere to i The distance of the point.

[0029] In one implementation, the step of obtaining a corrected high-resolution gravity field model by calculating the corrected internal spherical disturbance potential includes:

[0030] Establishing an observation equation according to the corrected internal spherical disturbance position and the preset gravity field model;

[0031] The observation equation is solved according to the least squares criterion to obtain the corrected gravity field model coefficients.

[0032] According to a second aspect, an embodiment provides a system for correcting elevation deviation of a gravity field model, comprising:

[0033] An acquisition module, used for acquiring GNSS / leveling data of a local area; the GNSS / leveling data includes geodetic height and normal height of a leveling point in the local area; the leveling point in the local area is on the surface of the earth;

[0034] An elevation anomaly calculation module, used to determine the elevation anomaly of the leveling point according to the GNSS / leveling data;

[0035] A disturbance position calculation module, used for calculating the disturbance position of the level point according to the elevation anomaly and the normal gravity of the projection point of the level point on the topographic surface;

[0036] A model disturbance position calculation module, used for obtaining the coordinate parameters of the leveling point, and calculating the model disturbance position of the leveling point according to the coordinate parameters and a preset gravity field model;

[0037] An earth surface disturbance position deviation calculation module is used to calculate the disturbance position deviation of the gravity field model on the earth surface according to the disturbance position and the model disturbance position;

[0038] An internal spherical surface disturbance potential deviation calculation module is used to select an internal spherical surface according to GNSS / leveling data of a local area, and determine the disturbance potential deviation of the internal spherical surface according to an integral relationship between the disturbance potential deviation of the earth surface and the disturbance potential deviation of the internal spherical surface;

[0039] An internal spherical surface model disturbance position calculation module, used for calculating the model disturbance position of the internal spherical surface according to the coordinate parameters of the internal spherical surface and the gravity field model;

[0040] An internal spherical surface disturbance position correction module is used to correct the model disturbance position of the internal spherical surface through the disturbance position deviation of the internal spherical surface to obtain the corrected internal spherical surface disturbance position;

[0041] The gravity field model correction module is used to obtain a corrected high-resolution gravity field model through calculation of the corrected internal spherical disturbance potential.

[0042] In one implementation, the internal spherical surface disturbance potential deviation calculation module determines the disturbance potential deviation of the internal spherical surface according to the integral relationship between the disturbance potential deviation of the earth surface and the disturbance potential deviation of the internal spherical surface, including:

[0043] According to Poisson integral, the integral relationship between the disturbance potential deviation on the earth's surface and the disturbance potential deviation on the internal spherical surface is established;

[0044] According to the discrete data of the selected inner sphere, the integral relation is discretized to obtain a discretized relation;

[0045] The perturbed position deviation of the earth surface is taken as the initial value of the perturbed position deviation of the inner spherical surface, and the discretized relational expression is iteratively solved to obtain the perturbed position deviation of the inner spherical surface.

[0046] According to a fourth aspect, an embodiment provides a computer-readable storage medium, on which a computer program is stored, and the computer program can be executed by a processor to implement the method as described above.

[0047] According to the fifth aspect, an embodiment provides a computer program product, comprising a computer program and / or instructions, wherein the computer program and / or instructions implement the method as described above when executed by a processor.

[0048] According to a method / system for correcting the elevation deviation of a gravity field model in the above-mentioned embodiment, GNSS / leveling data of a local area is obtained to calculate the elevation anomaly of the leveling point, and then the disturbance position of the leveling point is calculated according to the elevation anomaly and the normal gravity of the projection point of the leveling point on the topographic surface; the coordinate parameters of the leveling point are obtained, and the coordinate parameters are substituted into a preset gravity field model to calculate the model disturbance position of the leveling point, and then the disturbance position deviation of the gravity field model on the earth's surface is calculated according to the disturbance position and the model disturbance position; then, according to the G leveling data of the local area, the disturbance position of the leveling point is calculated according to the model disturbance position. The NSS / leveling data selects the internal sphere, and the disturbance position deviation of the internal sphere is calculated according to the integral relationship between the disturbance position deviation of the earth's surface and the disturbance position deviation of the internal sphere. At the same time, the coordinate parameters of the internal sphere are substituted into the gravity field model to calculate the model disturbance position of the internal sphere; finally, the model disturbance position of the internal sphere is corrected by the disturbance position deviation of the internal sphere to obtain the corrected internal sphere disturbance position, and then the gravity field model is calculated by the corrected internal sphere disturbance position to obtain the corrected high-resolution gravity field model. The corrected high-resolution gravity field model obtained by adopting the scheme of the present application can effectively correct the local elevation deviation of the model and realize the high-precision calculation of local elevation anomalies. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A flow chart of a method for correcting elevation deviation of a gravity field model provided in this embodiment;

[0050] Figure 2 A flow chart for determining the internal disturbance position deviation of the earth provided in this embodiment;

[0051] Figure 3 A flow chart for obtaining a high-resolution gravity field model provided in this embodiment;

[0052] Figure 4 A structural block diagram of the system for correcting the elevation deviation of the gravity field model provided in this embodiment.

[0053] Figure numerals: 10, acquisition module; 20, elevation anomaly calculation module; 30, disturbance position calculation module; 40, model disturbance position calculation module; 50, earth surface disturbance position deviation calculation module; 60, internal spherical disturbance position deviation calculation module; 70, internal spherical model disturbance position calculation module; 80, internal spherical disturbance position correction module; 90, gravity field model correction module. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0055] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0056] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0057] The high-resolution gravity field model of this embodiment has a wide range of application scenarios, and can be specifically applied in fields such as geodesy. Specifically, when it is applied to geodesy, the high-resolution gravity field model is crucial for determining the global centimeter-level geoid, which is a gravity equipotential surface consistent with the still sea surface without tides. Its precise measurement requires the support of the earth's gravity field. Therefore, how to obtain a high-resolution gravity field model is crucial. The present application provides a method for correcting the elevation deviation of a gravity field model to obtain a high-resolution gravity field model, and the specific method is as follows:

[0058] like Figure 1 As shown, the present embodiment provides a method for correcting the elevation deviation of a gravity field model, comprising the following steps:

[0059] Step 100: Acquire GNSS / leveling data of a local area through an acquisition module; the GNSS / leveling data includes the geodetic height and normal height of leveling points in the local area; the leveling points in the local area are on the surface of the earth.

[0060] GNSS / leveling data refers to the elevation information obtained through the global navigation satellite system (such as GPS, GLONASS, Galileo, BDS, etc.), and is combined with leveling data for joint processing to improve the accuracy and reliability of elevation measurement. The GNSS system can provide high-precision three-dimensional coordinates (longitude, latitude and elevation), while leveling can directly measure the elevation of ground points. The GNSS / leveling data in this step are leveling points marked with elevation data, and multiple leveling points can be obtained. Therefore, GNSS / leveling data includes the geodetic height and normal height of the leveling points in the local area.

[0061] Step 200: The elevation anomaly calculation module determines the elevation anomaly of the leveling point according to the GNSS / leveling data.

[0062] For example, the earth height of a point on the ground is H 大 , normal height is H 正 , then the elevation anomaly of the point ξ i for: ξ i = H 大 - H 正 .

[0063] Step 300: The disturbance position calculation module calculates the disturbance position of the level point according to the elevation anomaly and the normal gravity of the projection point of the level point on the similar terrain surface.

[0064] A quasi-terrestrial surface is a surface defined by the astronomical longitude and latitude of a ground point and the normal height of the corresponding point calculated from the normal ellipsoid. Q Normal position on U Equal to the corresponding point on the Earth's surface P Actual gravity position W The elevation anomaly is the approximate terrain surface Q Point to Earth's Surface P The distance of the point.

[0065] In this step, according to the Molodensky boundary value problem, the ground level point i The disturbance position and elevation anomaly of the point satisfy the Bruns formula:

[0066] ;

[0067] In the formula, express i The disturbance position of the point, Represents the Earth's surface i The elevation anomaly of the point, It represents the normal gravity of the projection point of the leveling point on the topographic surface.

[0068] Therefore, after calculating the elevation anomaly, the disturbance position of the leveling point can be calculated according to the above-mentioned Bruns formula, that is: .

[0069] Step 400: Obtain the coordinate parameters of the leveling point, and the model disturbance position calculation module calculates the model disturbance position of the leveling point according to the coordinate parameters and a preset gravity field model.

[0070] In this step, the coordinate parameters of the leveling point can be obtained through the GNSS system. After obtaining the coordinate parameters of the leveling point, the coordinate parameters are substituted into the preset gravity field model to obtain the model disturbance position of the leveling point. At this time, the gravity field model has not been calibrated.

[0071] Step 500: The earth surface disturbance potential deviation calculation module calculates the disturbance potential deviation of the gravity field model on the earth surface according to the disturbance potential and the model disturbance potential.

[0072] After obtaining the disturbance position and the model disturbance position of the level point in the above steps, the disturbance position deviation between the disturbance position and the model disturbance position is calculated. Specifically, the calculation formula is: ;in, is the disturbance potential deviation of the earth's surface, is the model disturbance position of the leveling point.

[0073] Step 600: The internal spherical surface disturbance potential deviation calculation module selects the internal spherical surface according to the GNSS / leveling data of the local area, and determines the disturbance potential deviation of the internal spherical surface according to the integral relationship between the disturbance potential deviation of the earth surface and the disturbance potential deviation of the internal spherical surface.

[0074] In practical applications, the internal sphere disturbance potential deviation calculation module selects a suitable internal sphere according to the characteristics of the local area, and then establishes the integral relationship between the earth surface disturbance potential deviation and the internal sphere disturbance potential deviation based on Poisson integral to solve the disturbance potential deviation of the internal sphere. .

[0075] Step 700: The internal spherical surface model disturbance potential calculation module calculates the model disturbance potential of the internal spherical surface according to the coordinate parameters of the internal spherical surface and the gravity field model.

[0076] Specifically, in this step, the coordinates of a point on the inner sphere are selected as reference coordinates, and the reference coordinates are substituted into the gravity field model for calculation to obtain the model disturbance position of the inner sphere. At this time, the gravity field model is also not corrected.

[0077] In this step, the calculation formula for calculating the model disturbance potential of the internal sphere is as follows:

[0078] ;

[0079] In the formula, represents the model perturbation potential of the inner sphere, G is the gravitational constant, M is the mass of the Earth, R is the inner spherical radius, and are the coefficients of the gravity field model, is the Legendre function, n is the order, m is the number of times, is the geocentric longitude of the interior sphere point, is the geocentric latitude of the interior sphere point, a is the semi-major axis of the reference ellipsoid.

[0080] Step 800: The internal spherical surface disturbance position correction module corrects the model disturbance position of the internal spherical surface through the disturbance position deviation of the internal spherical surface to obtain the corrected internal spherical surface disturbance position.

[0081] In this step, the model disturbance position of the inner sphere is corrected by the calculated disturbance position deviation of the inner sphere to obtain the corrected disturbance position of the inner sphere. The correction formula is: ;in, represents the corrected internal spherical disturbance bit, represents the perturbation deviation of the inner sphere, is the model perturbation potential of the inner sphere.

[0082] Step 900: The gravity field model correction module obtains a corrected high-resolution gravity field model by calculating the corrected internal spherical disturbance potential.

[0083] After the corrected internal spherical disturbance position is calculated in the above steps, the gravity field model is corrected by the corrected internal spherical disturbance position, the model coefficients of the new gravity field model are calculated, and the calculated model coefficients are used as the coefficients of the gravity field model to obtain the corrected high-resolution gravity field model. After the gravity field model is corrected, the model can be used to calculate the high-precision and high-resolution elevation anomaly of the local area for applications such as elevation benchmark conversion and GNSS elevation measurement.

[0084] By adopting the method of correcting the elevation deviation of the gravity field model of this embodiment, the local elevation deviation of the model can be effectively corrected, the local high-precision elevation anomaly can be calculated, and the elevation benchmark conversion, GNSS elevation measurement and other tasks in the local area can be supported.

[0085] Furthermore, the calculation level point of this embodiment iThe calculation formula of the model disturbance position of a point is as follows:

[0086] ;

[0087] In the formula, express i The model perturbation position of the point, G is the gravitational constant, M is the mass of the Earth, r for i The distance from a point to the center of the earth, and are the coefficients of the gravity field model, is the Legendre function, n is the order, m is the number of times, is the geocentric longitude, is the geocentric latitude, a is the semi-major axis of the reference ellipsoid.

[0088] Furthermore, in step 600, the disturbance potential deviation of the inner spherical surface is determined according to the integral relationship between the disturbance potential deviation of the earth surface and the disturbance potential deviation of the inner spherical surface, which specifically includes the following steps:

[0089] Step 610: Based on Poisson integral, establish an integral relationship between the disturbance potential deviation on the earth's surface and the disturbance potential deviation on the internal spherical surface.

[0090] According to the disturbance of the earth's surface , the Poisson integral can be used to establish the perturbation potential deviation on the inner sphere and The integral relationship is:

[0091] ;

[0092] In the formula, is the disturbance potential deviation of the earth's surface, r for i The distance from a point to the center of the earth, for i The geocentric longitude of a point, for i The geocentric latitude of the point, is the perturbation deviation of the inner sphere, is the geocentric longitude of the interior sphere point, is the geocentric latitude of the interior sphere point, R is the inner spherical radius, l For the inner sphere point i The distance of the point.

[0093] Step 620: Discretize the integral relational expression based on the discrete data of the selected inner sphere to obtain a discretized relational expression.

[0094] Select multiple points on the internal sphere and obtain the coordinate parameters of the multiple points. The coordinate parameters of the multiple points are discrete data. Substitute the discrete data into the above integral relationship and discretize the integral to obtain: Bf=g ,in, B is the matrix coefficient, f represents the perturbation deviation of the inner sphere, g is the disturbance potential deviation of the earth's surface.

[0095] Step 630: Using the perturbed position deviation of the earth surface as the initial value of the perturbed position deviation of the inner sphere, iteratively solve the discretized relationship to obtain the perturbed position deviation of the inner sphere .

[0096] Iterate and solve the discretized relational expression in the above steps, and convert the matrix coefficients B Replace with B=1-A , so the integral discretization form becomes: f=Af+g , taking the perturbation potential deviation of the earth's surface as the initial value of the perturbation potential deviation of the internal sphere, the iterative formula is: f i =Af i-1 +g After iterating the formula, the perturbation position deviation of the inner sphere can be obtained. .

[0097] Further, in step 900, the corrected internal spherical surface disturbance position T The corrected high-resolution gravity field model is calculated, which specifically includes the following steps:

[0098] Step 910: Establishing observation equations according to the corrected internal spherical disturbance potential and the preset gravity field model.

[0099] Corrected internal spherical disturbance T The following relationship exists with the gravity field model coefficient of the gravity field model:

[0100] ;

[0101] According to this relationship, the observation equation is established as follows: v=KX-l ,in, X is the coefficient of the gravity field model to be determined, l is the perturbation deviation of the inner sphere.

[0102] Step 920: Solve the observation equation according to the least squares criterion to obtain the corrected gravity field model coefficients.

[0103] According to the least squares criterion, the model coefficients can be calculated and After obtaining the model coefficients, it is equivalent to obtaining a high-resolution gravity field model after elevation benchmark correction.

[0104] In summary, the above-mentioned solution of the present application can effectively correct the local elevation deviation of the model and calculate the local high-precision elevation anomaly.

[0105] like Figure 4 As shown, the present embodiment provides a system for correcting the elevation deviation of a gravity field model, comprising an acquisition module 10, an elevation anomaly calculation module 20, a disturbance position calculation module 30, a model disturbance position calculation module 40, an earth surface disturbance position deviation calculation module 50, an internal spherical disturbance position deviation calculation module 60, an internal spherical model disturbance position calculation module 70, an internal spherical disturbance position correction module 80 and a gravity field model correction module 90.

[0106] Specifically, the acquisition module 10 is used to acquire the GNSS / leveling data of the local area; the GNSS / leveling data includes the geodetic height and normal height of the leveling point in the local area; the leveling point in the local area is on the surface of the earth; the elevation anomaly calculation module 20 is used to determine the elevation anomaly of the leveling point according to the GNSS / leveling data; the disturbance position calculation module 30 is used to calculate the disturbance position of the leveling point according to the elevation anomaly and the normal gravity of the projection point of the leveling point on the terrain-like surface; the model disturbance position calculation module 40 is used to obtain the coordinate parameters of the leveling point, and calculate the model disturbance position of the leveling point according to the coordinate parameters and the preset gravity field model; the earth surface disturbance position deviation calculation module 50 is used to calculate the gravity field model according to the disturbance position and the model disturbance position The module 60 is used to calculate the disturbance potential deviation of the model on the earth's surface; the module 60 for calculating the disturbance potential deviation of the internal sphere is used to select the internal sphere according to the GNSS / leveling data of the local area, and determine the disturbance potential deviation of the internal sphere according to the integral relationship between the disturbance potential deviation of the earth's surface and the disturbance potential deviation of the internal sphere; the module 70 for calculating the model disturbance potential of the internal sphere according to the coordinate parameters of the internal sphere and the gravity field model; the module 80 for correcting the model disturbance potential of the internal sphere by the disturbance potential deviation of the internal sphere to obtain the corrected internal sphere disturbance potential; the module 90 for correcting the gravity field model is used to obtain the corrected high-resolution gravity field model by calculating the corrected internal sphere disturbance potential.

[0107] The system for correcting the elevation deviation of the gravity field model in this embodiment has been described in detail in the above-mentioned method embodiment for correcting the elevation deviation of the gravity field model, and will not be elaborated in detail in this embodiment.

[0108] Furthermore, in the internal spherical surface disturbance potential deviation calculation module 60, the disturbance potential deviation of the internal spherical surface is determined according to the integral relationship between the disturbance potential deviation of the earth's surface and the disturbance potential deviation of the internal spherical surface, including: establishing an integral relationship between the disturbance potential deviation of the earth's surface and the disturbance potential deviation of the internal spherical surface according to Poisson's integral; discretizing the integral relationship according to the selected discrete data of the internal spherical surface to obtain a discretized relationship; taking the disturbance potential deviation of the earth's surface as the initial value of the disturbance potential deviation of the internal spherical surface, and iteratively solving the discretized relationship to obtain the disturbance potential deviation of the internal spherical surface.

[0109] In this embodiment, the specific implementation of the internal spherical disturbance position deviation calculation module has also been described in detail in the above-mentioned method embodiment for correcting the elevation deviation of the gravity field model, and this embodiment will not be repeated here.

[0110] This embodiment provides a computer-readable storage medium, on which a computer program is stored, and the computer program can be executed by a processor to implement the above method for correcting the elevation deviation of the gravity field model. Since the method for correcting the elevation deviation of the gravity field model has been described in detail in the above embodiment, this embodiment will not be described in detail here.

[0111] The present embodiment provides a computer program product, including a computer program and / or an instruction, which implements the above method for correcting the elevation deviation of the gravity field model when the computer program and / or the instruction is executed by a processor. In view of the fact that the method for correcting the elevation deviation of the gravity field model has been described in detail in the above embodiment, this embodiment will not be described in detail here.

[0112] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0113] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A method for correcting the elevation deviation of a gravity field model, It is characterized in that include: Obtain GNSS / leveling data for local areas; The GNSS / leveling data includes the geodetic height and normal height of the leveling points in the local area; The level point of the local area is located on the surface of the earth; Determine the elevation anomaly of the leveling point according to the GNSS / leveling data; The disturbance position of the leveling point is calculated according to the elevation anomaly and the normal gravity of the projection point of the leveling point on the topographic surface; the calculation formula for calculating the disturbance position of the leveling point is as follows: ； In the formula, express i The disturbance position of the point, Represents the Earth's surface i The elevation anomaly of the point, It represents the normal gravity of the projection point of the level point on the topographic surface; The coordinate parameters of the leveling point are obtained, and the model disturbance position of the leveling point is calculated according to the coordinate parameters and a preset gravity field model; the calculation formula for calculating the model disturbance position of the leveling point is as follows: ； In the formula, express i The model perturbation position of the point, G is the gravitational constant, M is the mass of the Earth, r for i The distance from a point to the center of the earth, and are the coefficients of the gravity field model, is the Legendre function, n is the order, m is the number of times, is the geocentric longitude, is the geocentric latitude, a is the semi-major axis of the reference ellipsoid; Calculating the disturbance position deviation of the gravity field model on the earth's surface according to the disturbance position and the model disturbance position; An internal sphere is selected according to GNSS / leveling data of a local area, and an integral relationship between the perturbation potential deviation of the earth's surface and the perturbation potential deviation of the internal sphere is established according to Poisson integral; the integral relationship is discretized according to the discrete data of the selected internal sphere to obtain a discretized relationship; the perturbation potential deviation of the earth's surface is used as the initial value of the perturbation potential deviation of the internal sphere, and the discretized relationship is iteratively solved to obtain the perturbation potential deviation of the internal sphere; Calculating the model disturbance position of the inner spherical surface according to the coordinate parameters of the inner spherical surface and the gravity field model; Correcting the model disturbance position of the inner spherical surface by the disturbance position deviation of the inner spherical surface to obtain the corrected disturbance position of the inner spherical surface; The corrected high-resolution gravity field model is obtained by calculating the corrected internal spherical disturbance potential.

2. The method for correcting the elevation deviation of a gravity field model according to claim 1, It is characterized in that The integral relationship is expressed as: ； In the formula, is the disturbance potential deviation of the earth's surface, is the perturbation deviation of the inner sphere, is the geocentric longitude of the inner sphere, is the geocentric latitude of the inner sphere, R is the inner spherical radius, l For the inner sphere to i The distance of the point.

3. The method for correcting the elevation deviation of a gravity field model according to claim 1, It is characterized in that The method of obtaining a corrected high-resolution gravity field model by calculating the corrected internal spherical disturbance potential comprises: Establishing an observation equation according to the corrected internal spherical disturbance position and the preset gravity field model; The observation equation is solved according to the least squares criterion to obtain the corrected gravity field model coefficients.

4. A system for correcting elevation deviations of gravity field models, It is characterized in that include: Acquisition module, used to obtain GNSS / leveling data of local area; The GNSS / leveling data includes the geodetic height and normal height of the leveling points in the local area; The level point of the local area is located on the surface of the earth; An elevation anomaly calculation module, used to determine the elevation anomaly of the leveling point according to the GNSS / leveling data; The disturbance level calculation module is used to calculate the disturbance level of the level point according to the elevation anomaly and the normal gravity of the projection point of the level point on the topographic surface; wherein the calculation formula for calculating the disturbance level of the level point is as follows: ； In the formula, express i The disturbance position of the point, Represents the Earth's surface i The elevation anomaly of the point, It represents the normal gravity of the projection point of the level point on the topographic surface; The model disturbance position calculation module is used to obtain the coordinate parameters of the leveling point, and calculate the model disturbance position of the leveling point according to the coordinate parameters and a preset gravity field model; wherein the calculation formula for calculating the model disturbance position of the leveling point is as follows: ； In the formula, express i The model perturbation position of the point, G is the gravitational constant, M is the mass of the Earth, r for i The distance from a point to the center of the earth, and are the coefficients of the gravity field model, is the Legendre function, n is the order, m is the number of times, is the geocentric longitude, is the geocentric latitude, a is the semi-major axis of the reference ellipsoid; An earth surface disturbance position deviation calculation module is used to calculate the disturbance position deviation of the gravity field model on the earth surface according to the disturbance position and the model disturbance position; The internal spherical surface disturbance position deviation calculation module is used to select the internal spherical surface according to the GNSS / leveling data of the local area, and establish the integral relationship between the disturbance position deviation of the earth surface and the disturbance position deviation of the internal spherical surface according to the Poisson integral; discretize the integral relationship according to the discrete data of the selected internal spherical surface to obtain a discretized relationship; use the disturbance position deviation of the earth surface as the initial value of the disturbance position deviation of the internal spherical surface, and iteratively solve the discretized relationship to obtain the disturbance position deviation of the internal spherical surface; An internal spherical surface model disturbance position calculation module, used for calculating the model disturbance position of the internal spherical surface according to the coordinate parameters of the internal spherical surface and the gravity field model; An internal spherical surface disturbance position correction module is used to correct the model disturbance position of the internal spherical surface through the disturbance position deviation of the internal spherical surface to obtain the corrected internal spherical surface disturbance position; The gravity field model correction module is used to obtain a corrected high-resolution gravity field model through calculation of the corrected internal spherical disturbance potential.

5. A computer-readable storage medium, It is characterized in that A computer program is stored on the medium, and the computer program can be executed by a processor to implement the method according to any one of claims 1 to 3.

6. A computer program product comprising a computer program and / or instructions, It is characterized in that When the computer program and / or the instructions are executed by a processor, the method according to any one of claims 1 to 3 is implemented.

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