A method and device for inverting ocean internal solitary wave amplitude lookup table

Abstract

The present invention proposes a method and device for inverting the amplitude of an internal solitary wave in the ocean through a lookup table. The method includes constructing a lookup table of multiple characteristic parameters of internal solitary waves under certain conditions of the ratio of total water depth to the thickness of the upper layer and the thickness of the lower layer of the ocean, and using the lookup table to invert the amplitude of the internal solitary wave, which includes a lookup table construction step and an amplitude inversion step. The present application uses a lookup table to carry out satellite ocean internal solitary wave amplitude inversion, which can not only greatly reduce the amount of calculation and simplify the dependence of satellite ocean internal solitary wave amplitude inversion technology on ocean dynamic processes, but also can synchronously provide the bright and dark spacing information of the internal solitary wave SAR remote sensing image through the lookup table, improve the understanding of the satellite ocean internal solitary wave remote sensing image, and in addition, the use of the lookup method can improve the accuracy of large-amplitude internal solitary wave amplitude inversion.

Description

Technical Field

[0001] The invention relates to the technical field of remote sensing measurement, and in particular to a method and a device for inverting an ocean internal solitary wave amplitude lookup table. Background Art

[0002] In the prediction and inversion technology of marine internal solitary waves, at present, many documents have been published for the prediction of internal solitary wave velocity, such as "Construction and Evaluation of Internal Solitary Wave Velocity-Gaussian Function Model", "Computer Algebraic Research on Internal Solitary Waves", "Propagation Evolution Characteristics of Weakly Nonlinear Internal Solitary Waves on Slopes" and other papers, as well as patent documents such as CN115859021B and CN118114030B, which all disclose how to obtain the propagation velocity of internal solitary waves through remote sensing means. However, there is no relatively fast and convenient solution for the remote sensing inversion of internal solitary wave amplitude at this stage. Summary of the invention

[0003] In order to make up for the above technical defects, this application proposes a method and device for inverting the amplitude lookup table of internal solitary waves in the ocean. The technical solution of the method includes:

[0004] A method for inverting the amplitude of an internal solitary wave in the ocean by using a lookup table, which constructs a lookup table of multiple characteristic parameters of internal solitary waves under certain conditions of the ratio of total water depth to the thickness of the upper and lower layers of the ocean, and uses the lookup table to invert the amplitude of the internal solitary wave, comprising a lookup table construction step and an amplitude inversion step;

[0005] The lookup table construction process includes: using the temperature-salinity profile data and total water depth of the internal solitary wave position and time observed by satellite to calculate the thickness and linear phase velocity of the upper and lower fluid layers in the two-layer fluid system; according to the thickness and linear phase velocity of the upper and lower fluid layers in the two-layer fluid system, using the eKdV equation to obtain different internal solitary wave propagation velocities and corresponding internal solitary wave amplitudes under a certain ratio of the upper and lower fluid thicknesses, and further according to the relationship between the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave on the SAR remote sensing imaging image, constructing a relationship diagram between the internal solitary wave propagation velocity and the internal solitary wave amplitude, and between the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave SAR remote sensing imaging image; by matching and setting an M×M grid in the relationship diagram, constructing three internal solitary wave characteristic parameter lookup tables of the internal solitary wave propagation velocity, the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave SAR remote sensing imaging image in the grid;

[0006] The internal solitary wave amplitude lookup table inversion step includes: inverting the internal solitary wave propagation velocity from the satellite ocean internal solitary wave remote sensing image; according to the lookup table, combining the observed internal solitary wave propagation velocity value and the upper and lower layer fluid thickness ratio of its observation position and corresponding time, using the lookup table to find the amplitude data of the observed internal solitary wave.

[0007] Furthermore, when the amplitude data of the observed internal solitary wave is found in the lookup table, the bright-dark spacing information of the internal solitary wave SAR remote sensing image is synchronously located through the lookup table.

[0008] Furthermore, the process of inverting the propagation velocity of the internal solitary wave from the satellite ocean internal solitary wave remote sensing image includes: using the interval distance L of the leading waves of adjacent internal waves measured on the remote sensing image to obtain the internal tide period T of the sea area, the propagation velocity C of the internal solitary wave can be obtained, that is: .

[0009] Furthermore, the process of calculating the thickness of the upper and lower layers of fluid in the two-layer fluid system includes:

[0010] Upper fluid thickness is the water depth at which the buoyancy frequency is at its maximum value. The buoyancy frequency N(z) is obtained by: ;

[0011] Where g is the acceleration due to gravity, is the seawater density, z is the water depth at this location, and the seawater density can be obtained through the temperature-salinity profile data provided by the numerical model;

[0012] Bottom fluid thickness =h- , h is the total water depth, obtained from the nautical chart;

[0013] The linear phase velocity c0 calculation process includes: ;

[0014] in, is the density of the upper fluid, is the density of the lower fluid, ;

[0015] The 1、 The ρ2 calculation process includes: , .

[0016] Furthermore, in the process of obtaining different internal solitary wave propagation velocities and corresponding internal solitary wave amplitudes under a certain ratio of the upper and lower fluid thicknesses through the eKdV equation, the eKdV equation is expressed as follows:

[0017] (1)

[0018] in, is the vertical displacement of the interface between the two layers of fluid at different times, the maximum value is the internal solitary wave amplitude, is the first-order nonlinear coefficient, is the second-order nonlinear coefficient, is the dispersion coefficient, and the above coefficient is obtained as follows:

[0019] (2)

[0020] The process of obtaining the internal solitary wave solution of the eKdV equation includes:

[0021] (3)

[0022] in, , and satisfies

[0023] (4)

[0024] Δ is the half-wave width, and the acquisition method includes:

[0025] (5)

[0026] c is the propagation velocity of the internal solitary wave, and the acquisition method includes:

[0027] (6)

[0028] After the internal solitary wave solution is obtained, the corresponding internal solitary wave amplitude is obtained according to the internal solitary wave solution.

[0029] An electronic device is configured to use the above method to invert the internal solitary wave amplitude.

[0030] The present application uses a lookup table to carry out satellite ocean internal solitary wave amplitude inversion, which can not only greatly reduce the amount of calculation and simplify the dependence of satellite ocean internal solitary wave amplitude inversion technology on ocean dynamic processes, but also can synchronously provide the bright and dark spacing information of internal solitary wave SAR remote sensing images through the lookup table, thereby improving the understanding of satellite ocean internal solitary wave remote sensing images. In addition, the use of this lookup method can improve the accuracy of large-amplitude internal solitary wave amplitude inversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a schematic flow chart of an embodiment of the method of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In one embodiment of the present application, the method of the present application includes: a method for inverting an internal solitary wave amplitude lookup table in the ocean, by constructing an internal solitary wave multi-characteristic parameter lookup table under certain conditions of the ratio of total water depth to the upper and lower ocean thicknesses, and using the lookup table to invert the internal solitary wave amplitude, which includes a lookup table construction step and an amplitude inversion step; the lookup table construction process includes:

[0036] Using satellite observations of internal solitary wave position and time, temperature and salinity profile data and total water depth, the thickness and linear phase velocity of the upper and lower fluid layers in a two-layer fluid system are calculated.

[0037] According to the thickness and linear phase velocity of the upper and lower fluid layers in the two-layer fluid system, the different internal solitary wave propagation velocities and the corresponding internal solitary wave amplitudes under a certain ratio of the upper and lower fluid thicknesses are obtained through the eKdV equation, and further, according to the relationship between the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave on the SAR remote sensing imaging image, the relationship diagrams between the internal solitary wave propagation velocity and the internal solitary wave amplitude, and between the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave SAR remote sensing imaging image are constructed. By matching and setting an M×M grid (M is an odd number and is generally taken as 99) in the relationship diagram, three internal solitary wave characteristic parameter lookup tables of the internal solitary wave propagation velocity, the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave SAR remote sensing imaging image are constructed in the grid;

[0038] The internal solitary wave amplitude lookup table inversion step includes: inverting the internal solitary wave propagation velocity from the satellite ocean internal solitary wave remote sensing image; according to the lookup table, combining the observed internal solitary wave propagation velocity value and the upper and lower layer fluid thickness ratio of its observation position and corresponding time, using the lookup table to find the internal solitary wave amplitude data of the observed internal solitary wave.

[0039] On the basis of the above embodiment, while finding the internal solitary wave amplitude data of the observed internal solitary wave in the lookup table, the bright-dark interval information of the internal solitary wave SAR remote sensing image is synchronously located through the lookup table.

[0040] On the basis of one or more of the above embodiments, the process of inverting the propagation velocity of the internal solitary wave from the satellite ocean internal solitary wave remote sensing image includes: using the interval distance L of the leading waves of adjacent internal waves measured on the remote sensing image to obtain the internal tide period T of the sea area, the propagation velocity C of the internal solitary wave can be obtained, that is: .

[0041] Based on one or more of the above embodiments, the process of calculating the thickness of the upper and lower layers of fluid in the two-layer fluid system includes:

[0042] Upper fluid thickness is the water depth at which the buoyancy frequency is at its maximum value. The buoyancy frequency N(z) is obtained by: ;

[0043] Where g is the acceleration due to gravity, is the seawater density, z is the water depth at this location, and the seawater density can be obtained through the temperature-salinity profile data provided by the numerical model;

[0044] Bottom fluid thickness =h- , h is the total water depth, obtained from the nautical chart;

[0045] The linear phase velocity c0 calculation process includes: ;

[0046] in, is the density of the upper fluid, is the density of the lower fluid, ;

[0047] The 1、 The ρ2 calculation process includes: , .

[0048] On the basis of one or more of the above embodiments, in the process of obtaining different internal solitary wave propagation velocities and corresponding internal solitary wave amplitudes under a certain ratio of the upper and lower fluid thicknesses through the eKdV equation, the eKdV equation is expressed as follows:

[0049] (1)

[0050] in, is the vertical displacement of the interface between the two layers of fluid at different times, the maximum value is the internal solitary wave amplitude, is the first-order nonlinear coefficient, is the second-order nonlinear coefficient, is the dispersion coefficient, and the above coefficient is obtained as follows:

[0051] (2)

[0052] The process of obtaining the internal solitary wave solution of the eKdV equation includes:

[0053] (3)

[0054] in, , and satisfies

[0055] (4)

[0056] Δ is the half-wave width, and the acquisition method includes:

[0057] (5)

[0058] c is the theoretically calculated internal solitary wave propagation velocity, and the acquisition method includes:

[0059] (6)

[0060] After the internal solitary wave solution is obtained, the corresponding internal solitary wave amplitude is obtained according to the internal solitary wave solution. , which can be obtained by the linear phase velocity acquisition method , and according to (2) we can get , , , and then given (3) ,Will , , , Substituting (4), (5) and (6), the propagation velocity of the internal solitary wave can be obtained from theoretical calculations, and a solitary wave solution (3) corresponding to the propagation velocity can be determined; exhaust all the solutions in (3) When , all different internal solitary wave propagation velocities and their corresponding internal solitary wave solutions are given; since each internal solitary wave solution has an internal solitary wave amplitude, different internal solitary wave propagation velocities and their corresponding internal solitary wave amplitudes can be given.

[0061] In this embodiment, the distance between the brightest point and the darkest point of the internal solitary wave on the SAR remote sensing image is obtained according to the internal solitary wave SAR remote sensing imaging model. The process includes:

[0062]

[0063] The lookup table is composed of M×M grid data matched in the relationship diagrams of different propagation speeds of internal solitary waves and internal solitary wave amplitudes, and internal solitary wave amplitudes and bright and dark intervals of internal solitary wave SAR remote sensing imaging images.

[0064] In the present application, the internal wave propagation velocity obtained from satellite ocean internal solitary wave remote sensing images is used to determine the internal solitary wave amplitude through a lookup table. The propagation velocity C obtained based on satellite observations is the same as the internal solitary wave propagation velocity c obtained by theoretical calculations. Therefore, the internal wave propagation velocity can be used to determine the internal solitary wave amplitude through the lookup table, and the light and dark spacing information of the observed internal solitary wave SAR remote sensing image can be synchronously found through the lookup table.

[0065] The present application also discloses an electronic device, which uses the method described in any one of the above embodiments to invert the internal solitary wave amplitude.

[0066] In this application, according to the different total water depths in the sea areas with high occurrence of internal waves in the ocean, the relationship diagrams of the three internal solitary wave characteristics, namely, the internal solitary wave propagation velocity, the internal solitary wave amplitude, and the brightness and darkness interval of the internal solitary wave SAR remote sensing imaging image, can be established in advance under different total water depths and different ratios of the upper and lower layer thicknesses of the ocean, and an M×M orthogonal matrix (M is an odd number, and is usually set to 99) can be matched in the relationship diagram to set a corresponding lookup table of the internal solitary wave propagation velocity-internal solitary wave amplitude-internal solitary wave SAR remote sensing image brightness and darkness interval. Later, in the application process of the internal solitary wave amplitude inversion, the internal solitary wave propagation velocity obtained by satellite ocean remote sensing or actual measurement is combined. According to the temperature-salinity profile data of the location and time of satellite ocean internal wave observation or actual measurement, the upper and lower fluid thicknesses and linear phase velocities under the two-layer fluid system are calculated. In this way, when the total water depth, the ratio of the thickness of the upper and lower layers of fluid, the propagation velocity of the internal solitary wave and the linear phase velocity are all known, the amplitude of the internal solitary wave can be uniquely determined through the corresponding lookup table of the internal solitary wave propagation velocity-internal solitary wave amplitude-internal solitary wave SAR remote sensing image brightness and darkness spacing formed in advance, and the corresponding internal solitary wave SAR remote sensing image brightness and darkness spacing information can also be obtained through the matrix lookup table. The present application can also be applied to the prediction and forecasting process of internal solitary waves. When the prediction information of the propagation velocity of the internal solitary wave is known, it can also be combined with the temperature-salinity profile data provided by the numerical model, and the prediction of the internal solitary wave amplitude and the brightness and darkness spacing information of the internal solitary wave SAR remote sensing image in sea areas with different total water depths can be realized through the above-mentioned pre-formed lookup table method, so that the prediction information of the internal solitary wave waveform can be more intuitively displayed.

[0067] The present application uses a lookup table to carry out satellite ocean internal solitary wave amplitude inversion, which can not only greatly reduce the amount of calculation and simplify the dependence of satellite ocean internal solitary wave amplitude inversion technology on ocean dynamic processes, but also can synchronously provide the bright and dark spacing information of internal solitary wave SAR remote sensing images through the lookup table, thereby improving the understanding of satellite ocean internal solitary wave remote sensing images. In addition, the use of this lookup method can improve the accuracy of large-amplitude internal solitary wave amplitude inversion.

[0068] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made to certain parts thereof by technicians in this technical field all reflect the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. A method for inverting an ocean solitary wave amplitude lookup table, characterized in that: By constructing a lookup table of multiple characteristic parameters of internal solitary waves under certain conditions of the ratio of total water depth to the thickness of the upper and lower layers of the ocean, the internal solitary wave amplitude is inverted using the lookup table, which includes a lookup table construction step and an amplitude inversion step; The lookup table construction process includes: Using satellite observations of internal solitary wave position and time, temperature and salinity profile data and total water depth, the thickness and linear phase velocity of the upper and lower fluid layers in a two-layer fluid system are calculated. According to the thickness and linear phase velocity of the upper and lower fluid layers in the two-layer fluid system, the different internal solitary wave propagation velocities and the corresponding internal solitary wave amplitudes under a certain ratio of the upper and lower fluid thicknesses are obtained through the eKdV equation, and further, according to the relationship between the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave on the SAR remote sensing imaging image, the relationship diagrams of the internal solitary wave propagation velocity and the internal solitary wave amplitude, and the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave SAR remote sensing imaging image are constructed, and an M×M grid is set in the relationship diagram, and three internal solitary wave characteristic parameter lookup tables of the internal solitary wave propagation velocity, the internal solitary wave amplitude and the bright-dark spacing of the internal solitary wave SAR remote sensing imaging image are constructed in the grid; The internal solitary wave amplitude lookup table inversion step comprises: Invert the propagation velocity of internal solitary waves from satellite ocean internal solitary wave remote sensing images; According to the lookup table, the internal solitary wave amplitude data of the observed internal solitary wave is found by combining the observed internal solitary wave propagation velocity value and the ratio of the upper and lower fluid thicknesses at the observation position and the corresponding time.

2. The method according to claim 1, characterized in that When the amplitude data of the observed internal solitary wave is found in the lookup table, the bright-dark spacing information of the internal solitary wave SAR remote sensing image is synchronously located through the lookup table.

3. The method according to claim 1, characterized in that The process of inverting the propagation velocity of internal solitary waves from the satellite ocean internal solitary wave remote sensing image includes: using the interval distance L of the leading waves of adjacent internal waves measured on the remote sensing image to obtain the internal tide period T of the sea area, the propagation velocity C of the internal solitary wave can be obtained, that is: .

4. The method according to claim 1, characterized in that: The process of calculating the thickness of the upper and lower layers of fluid in the two-layer fluid system includes: Upper fluid thickness is the water depth at which the buoyancy frequency is at its maximum value. The buoyancy frequency N(z) is obtained by: ; Where g is the acceleration due to gravity, is the seawater density, z is the water depth at this location, and the seawater density can be obtained through the temperature-salinity profile data provided by the numerical model; Bottom fluid thickness =h- , h is the total water depth, obtained from the nautical chart; The linear phase velocity c0 calculation process includes: ; in, is the density of the upper fluid, is the density of the lower fluid, ; The 1、 The ρ2 calculation process includes: , .

5. The method according to claim 4, characterized in that In the process of obtaining different internal solitary wave propagation velocities and corresponding internal solitary wave amplitudes under a certain ratio of the upper and lower fluid thicknesses through the eKdV equation, the eKdV equation is expressed as follows: ; in, is the vertical displacement of the interface between the two layers of fluid at different times, the maximum value is the internal solitary wave amplitude, is the first-order nonlinear coefficient, is the second-order nonlinear coefficient, is the dispersion coefficient, and the above coefficient is obtained as follows: ; The process of obtaining the internal solitary wave solution of the eKdV equation includes: ; in, , and satisfies ; Δ is the half-wave width, and the acquisition method includes: ; c is the propagation velocity of the internal solitary wave, and the acquisition method includes: ; After the internal solitary wave solution is obtained, the corresponding internal solitary wave amplitude is obtained according to the internal solitary wave solution.

6. An electronic device, characterized in that: The device uses the method according to any one of claims 1 to 5 to invert the internal solitary wave amplitude.

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