A gravity anomaly underwater continuation method and device based on upright hexahedron subdivision

Abstract

The application provides a gravity anomaly underwater continuation method and device based on an upright hexahedron section, a track gravity anomaly of a submarine is read by a boat-borne gravimeter; an upward continuation calculation surface elevation is obtained, the track gravity anomaly is upwardly continued to the calculation surface to obtain a continuation gravity anomaly; a seawater gravity anomaly is calculated by constructing an upright hexahedron model; an upward continuation gravity correction value is calculated according to the continuation gravity anomaly and the seawater gravity anomaly; a standard deviation of a difference value between a sea surface gravity anomaly and the upward continuation gravity correction value is calculated; if the standard deviation is less than or equal to a continuation threshold value, the upward continuation gravity correction value is determined as the continuation gravity value; real-time coordinates of the submarine are obtained according to the track gravity anomaly and the continuation gravity value. The track gravity anomaly and the sea surface gravity anomaly are matched on the same observation surface, the positioning accuracy of gravity matching navigation is enhanced, the continuation result is more accurate, and the matching speed is faster.

Description

Technical Field

[0001] This invention relates to the field of information processing technology, and in particular to a gravity anomaly underwater extension method and apparatus based on upright hexahedral subdivision. Background Technology

[0002] As the primary underwater combat platform, submersibles need to possess the ability to navigate covertly for extended periods to protect maritime borders. Underwater gravity matching navigation technology, due to its excellent "stealth," is the greatest guarantee for submersibles to navigate covertly and accurately for long periods.

[0003] Underwater gravity matching navigation uses global ocean gravity anomaly maps obtained from altimetry satellite data, pre-loaded into the submersible's navigation terminal as a navigation reference. Gravity anomaly values ​​on the track are measured in real time using an onboard gravimeter. The track gravity anomaly measurements over a period of time are matched with the pre-loaded ocean gravity anomaly map to obtain the submersible's own coordinates, which are then used to correct the inertial navigation system.

[0004] However, in the process of implementing the technical solutions in the embodiments of this application, the inventors of this application discovered that the above-mentioned prior art has at least the following technical problems:

[0005] In the existing technology, when matching the track gravity anomaly measurement results with the pre-installed ocean gravity anomaly map, there is a technical problem that the matching effect is poor because the track gravity anomaly is measured at the depth of the submersible's navigation, while the pre-installed ocean gravity anomaly map is measured at the sea surface. This results in the two being located at different elevation planes. Summary of the Invention

[0006] This invention provides an underwater gravity anomaly extrapolation method and apparatus based on hexahedral subdivision, addressing the technical problem in existing technologies where matching track gravity anomaly measurements with pre-installed ocean gravity anomaly maps results in poor matching due to the difference in elevation planes between the track gravity anomaly measurements (observed at the submersible's depth) and the pre-installed ocean gravity anomaly maps (observed at the sea surface). By subdividing the seawater layer using a hexahedral model and converting the track gravity anomaly to the sea surface, matching the track gravity anomaly and the sea surface gravity anomaly on the same observation plane enhances the positioning accuracy of gravity matching navigation. Furthermore, by considering the influence of seawater gravity, the extrapolation results are more accurate, thereby reducing matching search time and achieving faster matching speeds.

[0007] In view of the above problems, embodiments of this application are proposed to provide a gravity anomaly underwater extension method and apparatus based on upright hexahedral subdivision.

[0008] In a first aspect, the present invention provides an underwater gravity anomaly extrapolation method based on upright hexahedral subdivision. The method includes: obtaining the track gravity anomaly of a submersible using an onboard gravimeter; obtaining the elevation of an upward extrapolation calculation surface; constructing an upright hexahedral model based on the track gravity anomaly and the elevation of the upward extrapolation calculation surface, and calculating the seawater gravity anomaly; extrapolating the track gravity anomaly upwards to the calculation surface based on the elevation of the upward extrapolation calculation surface, obtaining the extrapolated gravity anomaly; and calculating the upward extrapolation based on the extrapolated gravity anomaly and the seawater gravity anomaly. Gravity correction value; obtain sea surface gravity anomaly; calculate the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value; obtain extension threshold; determine whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold; if the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, determine that the upward extension gravity correction value is the extension gravity value; obtain the real-time coordinates of the submersible based on the track gravity anomaly and the extension gravity value.

[0009] Preferably, the method further includes:

[0010] If the standard deviation is not less than or equal to the extension threshold, calculate the sum of the difference between the sea surface gravity anomaly and the upward extension gravity correction value and the track gravity anomaly to obtain the second track gravity anomaly.

[0011] Based on the elevation of the upward extension calculation surface, the gravity anomaly of the second track is extended upward to the calculation surface to obtain the second extended gravity anomaly;

[0012] Calculate the second upward extension gravity correction value based on the second extension gravity anomaly and the seawater gravity anomaly;

[0013] Calculate the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value;

[0014] Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold;

[0015] If the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold, the second upward extension gravity correction value is determined to be the extension gravity value;

[0016] The real-time coordinates of the submersible are obtained based on the track gravity anomaly and the second extended gravity value.

[0017] Preferably, obtaining the gravity anomaly of the submersible's trajectory using an onboard gravimeter includes:

[0018] Obtain the raw observation data from the submarine-borne gravimeter, wherein the sequence of the raw observation data is (L i B i ,TH,△Tg i ), i = 1, ..., p;

[0019] Among them, L i The longitude of the submersible;

[0020] B i The latitude of the submersible;

[0021] TH represents the depth of the submersible, and the depth is a constant value;

[0022] △Tg i The trajectory of the submersible exhibits a gravity anomaly.

[0023] p is the number of sequences;

[0024] Detect the missing point between the i-th point and the (i+1)-th point in the original observation data sequence;

[0025] Calculate the number of missing points p′;

[0026] Fill in the missing points between point i and point i+1;

[0027] By merging the missing points with the original observation data, the track gravity anomaly of the submersible is obtained, wherein the track gravity anomaly of the submersible is (L i B i ,TH,△Tg i ), i=1,...,k, k=p+p′.

[0028] Preferably, obtaining the elevation of the upward extension calculation surface includes:

[0029] Read the sea surface topography map of the area where the submersible is located, wherein the sea surface topography map is represented as (L ii,jj B ii,jj HM ii,jj ), ii = 1, ..., m, jj = 1, ..., n, where m is the number of horizontal rows and n is the number of vertical rows;

[0030] Among them, L ii,jj The longitude of the aforementioned sea surface topographic map;

[0031] B ii,jj The latitude of the aforementioned sea surface topographic map;

[0032] HM ii,jj The sea surface topography is shown in the aforementioned sea surface topography map;

[0033] The latitude and longitude of the gravity anomaly of the flight path are projected onto the sea surface topographic map;

[0034] The longitude and latitude in the sea surface topography map are compared one by one with the longitude and latitude in the track gravity anomaly to filter out the sea surface topography data, wherein the sea surface topography data is (L i B i HM' i ), i = 1, ..., k, HM' i =HM ii,jj ;

[0035] Calculate the maximum value of the sea surface topography data;

[0036] Based on the maximum value of the sea surface topography data, the elevation of the upward extension calculation surface is obtained, wherein the elevation of the upward extension calculation surface is expressed as JH = max(HM' i )+1,i=1,2,...,k.

[0037] Preferably, the step of constructing a vertical hexahedron model based on the track gravity anomaly and the elevation of the upwardly extended calculation surface, and calculating the seawater gravity anomaly, includes:

[0038] A vertical hexahedral model of the seawater layer is constructed, wherein the vertical hexahedral model has the depth TH of the submersible as the base and the sea surface topography HM' as the top. i The top face is a square with side length D on the bottom face of each upright hexahedron;

[0039] Based on the upright hexahedral model, the seawater layer is segmented, and the seawater gravity anomaly is calculated.

[0040] Preferably, obtaining the sea surface gravity anomaly includes:

[0041] Read the ocean gravity anomaly map of the area where the submersible is located, wherein the ocean gravity anomaly map is represented as (L ii,jj B ii,jj , △Hg ii,jj ), ii = 1, ..., m, jj = 1, ..., n, where m is the number of horizontal rows and n is the number of vertical rows;

[0042] Among them, L ii,jj The longitude of the aforementioned ocean gravity anomaly map;

[0043] B ii,jj The latitude of the aforementioned ocean gravity anomaly map;

[0044] △Hg ii,jj The ocean surface gravity anomaly is shown in the aforementioned ocean gravity anomaly map.

[0045] Project the latitude and longitude of the track gravity anomaly onto the ocean gravity anomaly map;

[0046] The longitude and latitude in the ocean gravity anomaly map are compared one by one with the longitude and latitude in the track gravity anomaly to filter out sea surface gravity anomalies. The sea surface gravity anomaly data is represented as (L... i B i , △Hg i ), i = 1, ..., k.

[0047] Preferably, the step of extending the track gravity anomaly upwards to the calculation surface based on the elevation of the upward extension calculation surface to obtain the extended gravity anomaly includes:

[0048] Regarding the ΔTg in the aforementioned track gravity anomaly i Perform a Fourier transform to obtain the first spectrum;

[0049] Multiply the first spectrum by the upward extension factor to obtain the second spectrum, wherein the second spectrum is the spectrum extended upward to the computational surface;

[0050] Perform an inverse Fourier transform on the second spectrum to obtain the extended gravity anomaly.

[0051] Secondly, the present invention provides an underwater extension device for gravity anomalies based on upright hexahedral subdivision, the device comprising:

[0052] The first acquisition unit is used to acquire the gravity anomaly of the submersible's trajectory through an onboard gravimeter;

[0053] The second obtaining unit is used to obtain the elevation of the upward extension calculation surface;

[0054] The first calculation unit is used to construct a vertical hexahedron model based on the track gravity anomaly and the elevation of the upward extension calculation surface, and to calculate the seawater gravity anomaly.

[0055] The third obtaining unit is used to extend the track gravity anomaly upward to the calculation surface according to the elevation of the upward extension calculation surface, and obtain the extended gravity anomaly.

[0056] The second calculation unit is used to calculate the upward extension gravity correction value based on the extension gravity anomaly and the seawater gravity anomaly.

[0057] The fourth obtaining unit is used to obtain the sea surface gravity anomaly;

[0058] The third calculation unit is used to calculate the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value.

[0059] The fifth obtaining unit is used to obtain the extension threshold;

[0060] The first judgment unit is used to determine whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold.

[0061] The first determining unit is configured to determine the upward extension gravity correction value as the extension gravity value if the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold.

[0062] The sixth obtaining unit is used to obtain the real-time coordinates of the submersible based on the track gravity anomaly and the extended gravity value.

[0063] Preferably, the device further includes:

[0064] The seventh obtaining unit is used to calculate the sum of the difference between the sea surface gravity anomaly and the upward extension gravity correction value and the track gravity anomaly if the standard deviation is not less than or equal to the extension threshold, so as to obtain the second track gravity anomaly.

[0065] The eighth obtaining unit is used to extend the second track gravity anomaly upward to the calculation surface according to the elevation of the upward extension calculation surface, and obtain the second extended gravity anomaly.

[0066] The fourth calculation unit is used to calculate the second upward extension gravity correction value based on the second extension gravity anomaly and the seawater gravity anomaly.

[0067] The fifth calculation unit is used to calculate the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value;

[0068] The second judgment unit is used to determine whether the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold.

[0069] The second determining unit is configured to determine the second upward extension gravity correction value as an extension gravity value if the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold.

[0070] The ninth obtaining unit is used to obtain the real-time coordinates of the submersible based on the track gravity anomaly and the second extended gravity value.

[0071] Preferably, the first obtaining unit includes:

[0072] The tenth acquisition unit is used to acquire the raw observation data of the shipborne gravimeter, wherein the sequence of the raw observation data is (L i B i ,TH,△Tg i ), i = 1, ..., p;

[0073] Among them, L i The longitude of the submersible;

[0074] B i The latitude of the submersible;

[0075] TH represents the depth of the submersible, and the depth is a constant value;

[0076] △Tg i The trajectory of the submersible exhibits a gravity anomaly.

[0077] p is the number of sequences;

[0078] The first detection unit is used to detect the missing point between the i-th point and the (i+1)-th point in the original observation data sequence.

[0079] The sixth calculation unit is used to calculate the number of missing points p′;

[0080] The first completion unit is used to complete the missing point between the i-th point and the (i+1)-th point.

[0081] The eleventh acquisition unit is used to merge the missing points with the original observation data to obtain the track gravity anomaly of the submersible, wherein the track gravity anomaly of the submersible is (L i B i ,TH,△Tg i ), i=1,...,k, k=p+p′.

[0082] Preferably, the second obtaining unit includes:

[0083] The first reading unit is used to read the sea surface topography map of the area where the submersible is located, wherein the sea surface topography map is represented as (L ii,jj B ii,jj HM ii,jj ), ii = 1, ..., m, jj = 1, ..., n, where m is the number of horizontal rows and n is the number of vertical rows;

[0084] Among them, L ii,jj The longitude of the aforementioned sea surface topographic map;

[0085] B ii,jjThe latitude of the aforementioned sea surface topographic map;

[0086] HM ii,jj The sea surface topography is shown in the aforementioned sea surface topography map;

[0087] A first projection unit is used to project the latitude and longitude of the gravity anomaly of the track onto the sea surface topographic map.

[0088] The first filtering unit is used to compare the longitude and latitude in the sea surface topography map with the longitude and latitude in the track gravity anomaly one by one to filter out the sea surface topography data, wherein the sea surface topography data is (L i B i HM' i ), i = 1, ..., k, HM' i =HM ii,jj ;

[0089] The seventh calculation unit is used to calculate the maximum value of the sea surface topography data;

[0090] The twelfth obtaining unit is used to obtain the elevation of the upward extension calculation surface based on the maximum value of the sea surface topography data, wherein the elevation of the upward extension calculation surface is expressed as JH = max(HM' i )+1,i=1,2,...,k.

[0091] Preferably, the first computing unit includes:

[0092] The first construction unit is used to construct a vertical hexahedral model of the seawater layer, wherein the vertical hexahedral model has the depth TH of the submersible as its base and the sea surface topography HM' as its topography. i The top face is a square with side length D on the bottom face of each upright hexahedron;

[0093] The eighth calculation unit is used to divide the seawater layer according to the upright hexahedral model and calculate the seawater gravity anomaly.

[0094] Preferably, the fourth obtaining unit includes:

[0095] The second reading unit is used to read the ocean gravity anomaly map of the area where the submersible is located, wherein the ocean gravity anomaly map is represented as (L ii,jj B ii,jj , △Hg ii,jj ), ii = 1, ..., m, jj = 1, ..., n, where m is the number of horizontal rows and n is the number of vertical rows;

[0096] Among them, L ii,jjThe longitude of the aforementioned ocean gravity anomaly map;

[0097] B ii,jj The latitude of the aforementioned ocean gravity anomaly map;

[0098] △Hg ii,jj The ocean surface gravity anomaly is shown in the aforementioned ocean gravity anomaly map.

[0099] The second projection unit is used to project the latitude and longitude of the track gravity anomaly onto the ocean gravity anomaly map;

[0100] The second filtering unit is used to compare the longitude and latitude in the ocean gravity anomaly map with the longitude and latitude in the track gravity anomaly one by one to filter out sea surface gravity anomalies, wherein the sea surface gravity anomaly data is represented as (L i B i , △Hg i ), i = 1, ..., k.

[0101] Preferably, the third obtaining unit includes:

[0102] The thirteenth obtaining unit is used to obtain ΔTg in the gravity anomaly of the track. i Perform a Fourier transform to obtain the first spectrum;

[0103] The fourteenth obtaining unit is used to multiply the first spectrum by an upward extension factor to obtain a second spectrum, wherein the second spectrum is a spectrum extended upward to the computational surface;

[0104] The fifteenth obtaining unit is used to perform an inverse Fourier transform on the second spectrum to obtain the extended gravity anomaly.

[0105] Thirdly, the present invention provides an underwater extension device for gravity anomalies based on upright hexahedral subdivision, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to perform the following steps:

[0106] Using an onboard gravimeter, the gravity anomaly of the submersible's trajectory is obtained; the elevation of the upward extension calculation surface is obtained; based on the gravity anomaly of the trajectory and the elevation of the upward extension calculation surface, a vertical hexahedral model is constructed to calculate the seawater gravity anomaly; based on the elevation of the upward extension calculation surface, the gravity anomaly of the trajectory is extended upward to the calculation surface to obtain the extended gravity anomaly; based on the extended gravity anomaly and the seawater gravity anomaly, the upward extension gravity correction value is calculated; the sea surface gravity anomaly is obtained; the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is calculated; an extension threshold is obtained; it is determined whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold; if the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, the upward extension gravity correction value is determined to be the extension gravity value; based on the gravity anomaly of the trajectory and the extension gravity value, the real-time coordinates of the submersible are obtained.

[0107] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0108] Using an onboard gravimeter, the gravity anomaly of the submersible's trajectory is obtained; the elevation of the upward extension calculation surface is obtained; based on the gravity anomaly of the trajectory and the elevation of the upward extension calculation surface, a vertical hexahedral model is constructed to calculate the seawater gravity anomaly; based on the elevation of the upward extension calculation surface, the gravity anomaly of the trajectory is extended upward to the calculation surface to obtain the extended gravity anomaly; based on the extended gravity anomaly and the seawater gravity anomaly, the upward extension gravity correction value is calculated; the sea surface gravity anomaly is obtained; the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is calculated; an extension threshold is obtained; it is determined whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold; if the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, the upward extension gravity correction value is determined to be the extension gravity value; based on the gravity anomaly of the trajectory and the extension gravity value, the real-time coordinates of the submersible are obtained.

[0109] The above-described one or more technical solutions in the embodiments of this application have at least one or more of the following technical effects:

[0110] This invention provides an underwater gravity anomaly extrapolation method and apparatus based on upright hexahedral subdivision. The method includes: obtaining the track gravity anomaly of a submersible using an onboard gravimeter; obtaining the elevation of the upward extrapolation calculation surface; constructing an upright hexahedral model based on the track gravity anomaly and the elevation of the upward extrapolation calculation surface, and calculating the seawater gravity anomaly; extrapolating the track gravity anomaly upward to the calculation surface based on the elevation of the upward extrapolation calculation surface, obtaining the extrapolated gravity anomaly; and calculating the upward extrapolation... The process involves: 1) Obtaining a gravity correction value; 2) Obtaining a sea surface gravity anomaly; 3) Calculating the standard deviation of the difference between the sea surface gravity anomaly and the upwardly extended gravity correction value; 4) Obtaining an extension threshold; 5) Determining whether the standard deviation of the difference between the sea surface gravity anomaly and the upwardly extended gravity correction value is less than or equal to the extension threshold; 6) If the standard deviation of the difference between the sea surface gravity anomaly and the upwardly extended gravity correction value is less than or equal to the extension threshold, determining the upwardly extended gravity correction value as an extended gravity value; 7) Obtaining the real-time coordinates of the submersible based on the track gravity anomaly and the extended gravity value. This method addresses the technical problem in the prior art where, when matching track gravity anomaly measurement results with a pre-installed ocean gravity anomaly map, the track gravity anomaly is measured at the depth of the submersible's navigation, while the pre-installed ocean gravity anomaly map is measured at the sea surface, resulting in different elevation planes and thus poor matching performance. The seawater layer is segmented based on the upright hexahedral model, and the gravity anomaly of the track is converted to the sea surface. This enables the matching of the gravity anomaly of the track and the gravity anomaly of the sea surface on the same observation surface, which enhances the positioning accuracy of gravity matching navigation. At the same time, considering the influence of the gravity of the seawater layer, the extrapolation results are more accurate, thereby achieving the technical effect of reducing matching search time and matching speed.

[0111] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0112] Figure 1 This is a flowchart illustrating an underwater extension method based on upright hexahedral subdivision under gravity anomalies in an embodiment of the present invention.

[0113] Figure 2 This is a schematic diagram of the structure of an underwater gravity anomaly extension device based on upright hexahedral subdivision in an embodiment of the present invention.

[0114] Figure 3 This is a schematic diagram of another underwater extension device based on upright hexahedral subdivision for gravity anomalies in an embodiment of the present invention.

[0115] Figure 4The above-ground map is selected from the sea surface topography maps in this embodiment of the invention;

[0116] Figure 5 This is a schematic diagram of the cross-section of an upright hexahedron in an embodiment of the present invention;

[0117] Figure 6 This is a schematic diagram of the upright hexahedron segmentation in an embodiment of the present invention;

[0118] Figure 7 This is a schematic diagram of the coordinates of a single upright hexahedron in an embodiment of the present invention;

[0119] Figure 8 This is a sea surface gravity anomaly image selected in an embodiment of the present invention.

[0120] Explanation of reference numerals in the attached drawings: First obtaining unit 1, second obtaining unit 2, first calculation unit 3, third obtaining unit 4, second calculation unit 5, fourth obtaining unit 6, third calculation unit 7, fifth obtaining unit 8, first judgment unit 9, first determination unit 10, sixth obtaining unit 11, bus 300, receiver 301, processor 302, transmitter 303, memory 304, bus interface 306. Detailed Implementation

[0121] This invention provides an underwater gravity anomaly extrapolation method and apparatus based on upright hexahedral subdivision, which solves the technical problem in the prior art that the matching effect is poor when matching track gravity anomaly measurement results with pre-installed ocean gravity anomaly maps because the two are located at different elevation planes.

[0122] The overall concept of the technical solution provided by this invention is as follows: Using an onboard gravimeter, the track gravity anomaly of the submersible is obtained; the elevation of the upward extension calculation surface is obtained; based on the track gravity anomaly and the elevation of the upward extension calculation surface, a vertical hexahedral model is constructed to calculate the seawater gravity anomaly; based on the elevation of the upward extension calculation surface, the track gravity anomaly is extended upwards to the calculation surface to obtain the extended gravity anomaly; based on the extended gravity anomaly and the seawater gravity anomaly, an upward extension gravity correction value is calculated; the sea surface gravity anomaly is obtained; the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is calculated; an extension threshold is obtained; it is determined whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold; if the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, the upward extension gravity correction value is determined to be the extension gravity value; based on the track gravity anomaly and the extension gravity value, the real-time coordinates of the submersible are obtained. The seawater layer is segmented based on the upright hexahedral model, and the gravity anomaly of the track is converted to the sea surface. This enables the matching of the gravity anomaly of the track and the gravity anomaly of the sea surface on the same observation surface, which enhances the positioning accuracy of gravity matching navigation. At the same time, considering the influence of the gravity of the seawater layer, the extrapolation results are more accurate, thereby achieving the technical effect of reducing matching search time and matching speed.

[0123] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0124] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0125] Example 1

[0126] Figure 1 This is a schematic flowchart of an underwater extension method based on upright hexahedral subdivision using gravity anomalies, as described in an embodiment of the present invention. Figure 1 As shown, this embodiment of the invention provides a gravity anomaly underwater extension method based on upright hexahedral subdivision, the method comprising:

[0127] Step s1: Obtain the gravity anomaly of the submersible's trajectory using the onboard gravimeter;

[0128] Step s2: Obtain the elevation of the upward extension calculation surface;

[0129] Step s3: Based on the gravity anomaly of the track and the elevation of the upward extension calculation surface, construct a vertical hexahedron model and calculate the seawater gravity anomaly;

[0130] Step s4: Based on the elevation of the upward extension calculation surface, extend the track gravity anomaly upward to the calculation surface to obtain the extended gravity anomaly;

[0131] Step s5: Calculate the upward extension gravity correction value based on the extension gravity anomaly and the seawater gravity anomaly;

[0132] Step s6: Obtain the sea surface gravity anomaly;

[0133] Step s7: Calculate the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value;

[0134] Step s8: Obtain the extension threshold;

[0135] Step s9: Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold;

[0136] Step s10: If the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, the upward extension gravity correction value is determined to be the extension gravity value.

[0137] Step s11: Obtain the real-time coordinates of the submersible based on the track gravity anomaly and the extended gravity value.

[0138] Specifically, firstly, the observation data along the submersible's trajectory is read using the observation results of the onboard gravimeter. This data includes the submersible's longitude, latitude, depth surface, and gravity anomaly, thus obtaining the submersible's gravity anomaly. Then, sea surface topography data at the same longitude and latitude as the trajectory gravity anomaly is selected from the sea surface topography map, thereby determining the elevation of the upwardly extended calculation surface. This establishes the seawater layer between the depth surface where the submersible is located and the upwardly extended calculation surface. In this embodiment, a vertical hexahedral model is constructed to segment the seawater layer and calculate its gravity influence. By considering the gravity influence of the seawater layer, the extension results are more accurate, thereby reducing matching search time and achieving faster matching speed. Next, based on the elevation of the upwardly extended calculation surface, the trajectory gravity anomaly is extended upwards to the calculation surface to obtain the extended gravity anomaly. The submersible's navigation terminal uses a pre-loaded ocean gravity anomaly map to obtain sea surface gravity anomalies as a navigation reference. The measurement results of the track gravity anomaly are matched with the sea surface gravity anomaly map to obtain the submersible's real-time coordinates, which are then used to correct the inertial navigation system. Specifically, the extended gravity anomaly is added to the seawater gravity anomaly to calculate an upward extended gravity correction value. Then, the sea surface gravity anomaly is subtracted from the upward extended gravity correction value to calculate the standard deviation of the difference. It is then determined whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extended gravity correction value is less than or equal to a preset extended threshold. If the standard deviation is less than or equal to the extended threshold, then the upward extended gravity correction value is determined to be the final extended gravity value of the track gravity anomaly. Finally, based on the track gravity anomaly and the extended gravity value, the submersible's real-time coordinates are further obtained, achieving the purpose of correcting the inertial navigation system. Furthermore, it enables the conversion of track gravity anomalies to the sea surface, achieving matching of track gravity anomalies and sea surface gravity anomalies on the same observation surface, thus enhancing the positioning accuracy of gravity matching navigation.

[0139] In step s1, obtaining the gravity anomaly of the submersible's trajectory using the onboard gravimeter specifically includes:

[0140] Obtain the raw observation data from the submarine-borne gravimeter, wherein the sequence of the raw observation data is (L i B i ,TH,△Tg i ), i = 1, ..., p;

[0141] Among them, L i The longitude of the submersible;

[0142] B i The latitude of the submersible;

[0143] TH represents the depth of the submersible, and the depth is a constant value;

[0144] △Tg i The trajectory of the submersible exhibits a gravity anomaly.

[0145] p is the number of sequences;

[0146] Detect the missing point between the i-th point and the (i+1)-th point in the original observation data sequence;

[0147] make

[0148] like

[0149] Then it is considered that there is a missing point between point i and point i+1.

[0150] Calculate the number of missing points p′, where,

[0151] int represents integer;

[0152] Fill in the missing points between point i and point i+1:

[0153] Let the missing point be (L) ii B ii ), ii=1,…,p',

[0154] but

[0155] By merging the missing points with the original observation data, the track gravity anomaly of the submersible is obtained, wherein the track gravity anomaly of the submersible is (L i B i ,TH,△Tg i ), i=1,...,k, k=p+p′.

[0156] In step s2, obtaining the elevation of the upward extension calculation surface specifically includes:

[0157] Read the sea surface topography map of the area where the submersible is located, wherein the sea surface topography map is represented as (L ii,jj B ii,jj HM ii,jj ), ii = 1, ..., m, jj = 1, ..., n, where m is the number of horizontal rows and n is the number of vertical rows;

[0158] Among them, L ii,jj The longitude of the aforementioned sea surface topographic map;

[0159] B ii,jj The latitude of the aforementioned sea surface topographic map;

[0160] HMii,jj The sea surface topography is shown in the aforementioned sea surface topography map;

[0161] The latitude and longitude of the gravity anomaly of the flight path are projected onto the sea surface topographic map;

[0162] The longitude and latitude in the sea surface topography map are compared one by one with the longitude and latitude in the gravity anomaly of the navigation track to filter out the sea surface topography data.

[0163] If latitude and longitude both satisfy L ii,jj =L i B ii,jj =B i , i=1,…,k, ii=1,…,m, jj=1,…,n

[0164] Then let HM' i =HM ii,jj , i=1,…,k, ii=1,…,m, jj=1,…,n

[0165] (L i B i HM' i ), i = 1, ..., k, which are the filtered sea surface topography data, such as Figure 4 As shown, the small dots represent the latitude and longitude of the gravity anomaly of the track projected onto the sea surface topographic map;

[0166] Calculate the maximum value of the sea surface topography data;

[0167] Based on the maximum value of the sea surface topography data, the elevation of the upward extension calculation surface is obtained, wherein the elevation of the upward extension calculation surface is expressed as JH = max(HM' i )+1,i=1,2,...,k.

[0168] In step s3, the process of constructing a vertical hexahedron model based on the track gravity anomaly and the elevation of the upwardly extended calculation surface, and calculating the seawater gravity anomaly, specifically includes:

[0169] Construct a vertical hexahedral model of the seawater layer and determine the dimensions of the vertical hexahedral model, such as... Figure 5 and Figure 6 As shown, the upright hexahedral model has the submersible's depth TH as its base and the sea surface topography HM' as its top surface. i The top face is a square with side length D on the bottom face of each upright hexahedron;

[0170] Based on the aforementioned upright hexahedral model, the seawater layer is segmented, and the seawater gravity anomaly is calculated, such as... Figure 7 As shown;

[0171] Let (x) i,y i ,z i ), where i = 1, 2, ..., k are the coordinates of the points to be calculated;

[0172] Let ξ, η, The coordinates of the eight corners of a vertical hexahedron;

[0173] Then the gravity anomaly at the point to be calculated (Δg) i (x i ,y i ,z i ), which will be written as Δg in the following text. i )for:

[0174]

[0175] Where: G is Newton's gravitational constant; k is the number of points to be calculated on the calculation surface, which is also the number of upright hexahedrons; μ uvw =(-1) u+v+w u,v,w=1,2; x u =x i -ξ i y v =y i -η v ,

[0176] In step s6, obtaining the sea surface gravity anomaly specifically includes:

[0177] Read the ocean gravity anomaly map of the area where the submersible is located, wherein the ocean gravity anomaly map is represented as (L ii,jj B ii,jj , △Hg ii,jj ), ii = 1, ..., m, jj = 1, ..., n, where m is the number of horizontal rows and n is the number of vertical rows;

[0178] Among them, L ii,jj The longitude of the aforementioned ocean gravity anomaly map;

[0179] B ii,jj The latitude of the aforementioned ocean gravity anomaly map;

[0180] △Hg ii,jj The ocean surface gravity anomaly is shown in the aforementioned ocean gravity anomaly map.

[0181] Project the latitude and longitude of the track gravity anomaly onto the ocean gravity anomaly map;

[0182] The longitude and latitude in the ocean gravity anomaly map are compared one by one with the longitude and latitude in the track gravity anomaly.

[0183] If latitude and longitude both satisfy L ii,jj =L i B ii,jj =B i , i=1,…,k, ii=1,…,m, jj=1,…,n

[0184] Then let (L) i B i , △Hg i ), i = 1, ..., k are the selected sea surface gravity anomaly data, such as Figure 8 As shown, the small dots represent the latitude and longitude of the gravity anomaly of the track as projected onto the sea surface gravity anomaly map.

[0185] In step s4, the process of extending the track gravity anomaly upwards to the calculation surface based on the elevation of the upward extension calculation surface to obtain the extended gravity anomaly specifically includes:

[0186] Regarding the ΔTg in the aforementioned track gravity anomaly i Perform Fourier transform on i = 1, ..., k to obtain the first spectrum;

[0187] UTG i =FFT(△Tg) i ), i = 1, ..., k

[0188] Multiply the first spectrum by the upward extension factor to obtain the second spectrum, wherein the second spectrum is the spectrum extended upward to the computational surface;

[0189] UTg' i =UTg i ×e h i = 1, ..., k

[0190] h = |JH-TH|

[0191] Perform an inverse Fourier transform on the second spectrum to obtain the extended gravity anomaly.

[0192] Ug i =IFFT(UTg' i ), i = 1, ..., k

[0193] Therefore, the upward extension of the gravity correction value Jg i =Ug i +Δg i i = 1, ..., k

[0194] At this point, let KK = 0.

[0195] Calculate the difference between the sea surface gravity anomaly and the correction value of the extended gravity anomaly:

[0196] δg i=|ΔHg i -Jg i |, i = 1, ..., k

[0197] Calculate the standard deviation of the difference:

[0198] γ=STD(δg i ), i = 1, ..., k

[0199] If γ≤ε, then Jg i The final continuation gravity result is i = 1, ..., k, and the process terminates.

[0200] If γ > ε, then let KK = KK + 1, ΔHg i =ΔHg i +δg i , i = 1, ..., k and repeat steps s4 to s11 until γ ≤ ε, to obtain the extended gravity value.

[0201] Furthermore, the method also includes:

[0202] If the standard deviation is not less than or equal to the extension threshold, calculate the sum of the difference between the sea surface gravity anomaly and the upward extension gravity correction value and the track gravity anomaly to obtain the second track gravity anomaly.

[0203] Based on the elevation of the upward extension calculation surface, the gravity anomaly of the second track is extended upward to the calculation surface to obtain the second extended gravity anomaly;

[0204] Calculate the second upward extension gravity correction value based on the second extension gravity anomaly and the seawater gravity anomaly;

[0205] Calculate the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value;

[0206] Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold;

[0207] If the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold, the second upward extension gravity correction value is determined to be the extension gravity value;

[0208] The real-time coordinates of the submersible are obtained based on the track gravity anomaly and the second extended gravity value.

[0209] Specifically, if the standard deviation is not less than or equal to the extension threshold, i.e., γ > ε, then the difference between the sea surface gravity anomaly and the upward extension gravity correction value is added to the track gravity anomaly to obtain a new track gravity anomaly, i.e., the second track gravity anomaly, and KK = KK + 1, ΔHg i =ΔHg i +δg i The process is terminated when the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value meets the range of the extension threshold. The extension gravity value is obtained, thereby obtaining the real-time coordinates of the submersible. This realizes the matching of track gravity anomaly and sea surface gravity anomaly on the same observation surface, enhancing the positioning accuracy of gravity matching navigation.

[0210] Example 2

[0211] Based on the same inventive concept as the gravity anomaly underwater extension method based on upright hexahedral partitioning in the foregoing embodiments, the present invention also provides a gravity anomaly underwater extension device based on upright hexahedral partitioning, such as... Figure 2 As shown, the device includes:

[0212] First acquisition unit 1, the first acquisition unit 1 is used to acquire the gravity anomaly of the submarine's trajectory through the onboard gravimeter;

[0213] The second obtaining unit 2 is used to obtain the elevation of the upward extension calculation surface;

[0214] The first calculation unit 3 is used to construct a vertical hexahedron model based on the track gravity anomaly and the elevation of the upward extension calculation surface, and to calculate the seawater gravity anomaly.

[0215] The third obtaining unit 4 is used to extend the track gravity anomaly upward to the calculation surface according to the elevation of the upward extension calculation surface, and obtain the extended gravity anomaly.

[0216] The second calculation unit 5 is used to calculate the upward extension gravity correction value based on the extension gravity anomaly and the seawater gravity anomaly.

[0217] The fourth obtaining unit 6 is used to obtain the sea surface gravity anomaly;

[0218] The third calculation unit 7 is used to calculate the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value.

[0219] The fifth obtaining unit 8 is used to obtain the extension threshold;

[0220] First judgment unit 9, the first judgment unit 9 is used to determine whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold.

[0221] The first determining unit 10 is configured to determine the upward extension gravity correction value as the extension gravity value if the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold.

[0222] The sixth obtaining unit 11 is used to obtain the real-time coordinates of the submersible based on the track gravity anomaly and the extended gravity value.

[0223] Furthermore, the device also includes:

[0224] The seventh obtaining unit is used to calculate the sum of the difference between the sea surface gravity anomaly and the upward extension gravity correction value and the track gravity anomaly if the standard deviation is not less than or equal to the extension threshold, so as to obtain the second track gravity anomaly.

[0225] The eighth obtaining unit is used to extend the second track gravity anomaly upward to the calculation surface according to the elevation of the upward extension calculation surface, and obtain the second extended gravity anomaly.

[0226] The fourth calculation unit is used to calculate the second upward extension gravity correction value based on the second extension gravity anomaly and the seawater gravity anomaly.

[0227] The fifth calculation unit is used to calculate the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value;

[0228] The second judgment unit is used to determine whether the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold.

[0229] The second determining unit is configured to determine the second upward extension gravity correction value as an extension gravity value if the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold.

[0230] The ninth obtaining unit is used to obtain the real-time coordinates of the submersible based on the track gravity anomaly and the second extended gravity value.

[0231] Furthermore, the first obtaining unit 1 includes:

[0232] The tenth acquisition unit is used to acquire the raw observation data of the shipborne gravimeter, wherein the sequence of the raw observation data is (L i B i ,TH,△Tg i ), i = 1, ..., p;

[0233] Among them, L i The longitude of the submersible;

[0234] B i The latitude of the submersible;

[0235] TH represents the depth of the submersible, and the depth is a constant value;

[0236] △Tg i The trajectory of the submersible exhibits a gravity anomaly.

[0237] p is the number of sequences;

[0238] The first detection unit is used to detect the missing point between the i-th point and the (i+1)-th point in the original observation data sequence.

[0239] The sixth calculation unit is used to calculate the number of missing points p′;

[0240] The first completion unit is used to complete the missing point between the i-th point and the (i+1)-th point.

[0241] The eleventh acquisition unit is used to merge the missing points with the original observation data to obtain the track gravity anomaly of the submersible, wherein the track gravity anomaly of the submersible is (L i B i ,TH,△Tg i ), i=1,...,k, k=p+p′.

[0242] Furthermore, the second obtaining unit 2 includes:

[0243] The first reading unit is used to read the sea surface topography map of the area where the submersible is located, wherein the sea surface topography map is represented as (L ii,jj B ii,jj HM ii,jj ), ii = 1, ..., m, jj = 1, ..., n, where m is the number of horizontal rows and n is the number of vertical rows;

[0244] Among them, L ii,jj The longitude of the aforementioned sea surface topographic map;

[0245] B ii,jj The latitude of the aforementioned sea surface topographic map;

[0246] HM ii,jj The sea surface topography is shown in the aforementioned sea surface topography map;

[0247] A first projection unit is used to project the latitude and longitude of the gravity anomaly of the track onto the sea surface topographic map.

[0248] The first filtering unit is used to compare the longitude and latitude in the sea surface topography map with the longitude and latitude in the track gravity anomaly one by one to filter out the sea surface topography data, wherein the sea surface topography data is (L i B i HM' i ), i = 1, ..., k, HM' i =HM ii,jj ;

[0249] The seventh calculation unit is used to calculate the maximum value of the sea surface topography data;

[0250] The twelfth obtaining unit is used to obtain the elevation of the upward extension calculation surface based on the maximum value of the sea surface topography data, wherein the elevation of the upward extension calculation surface is expressed as JH = max(HM' i )+1,i=1,2,...,k.

[0251] Furthermore, the first computing unit 3 includes:

[0252] The first construction unit is used to construct a vertical hexahedral model of the seawater layer, wherein the vertical hexahedral model has the depth TH of the submersible as its base and the sea surface topography HM' as its topography. i The top face is a square with side length D on the bottom face of each upright hexahedron;

[0253] The eighth calculation unit is used to divide the seawater layer according to the upright hexahedral model and calculate the seawater gravity anomaly.

[0254] Furthermore, the fourth obtaining unit 6 includes:

[0255] The second reading unit is used to read the ocean gravity anomaly map of the area where the submersible is located, wherein the ocean gravity anomaly map is represented as (L ii,jj B ii,jj , △Hg ii,jj ), ii = 1, ..., m, jj = 1, ..., n, where m is the number of horizontal rows and n is the number of vertical rows;

[0256] Among them, L ii,jjThe longitude of the aforementioned ocean gravity anomaly map;

[0257] B ii,jj The latitude of the aforementioned ocean gravity anomaly map;

[0258] △Hg ii,jj The ocean surface gravity anomaly is shown in the aforementioned ocean gravity anomaly map.

[0259] The second projection unit is used to project the latitude and longitude of the track gravity anomaly onto the ocean gravity anomaly map;

[0260] The second filtering unit is used to compare the longitude and latitude in the ocean gravity anomaly map with the longitude and latitude in the track gravity anomaly one by one to filter out sea surface gravity anomalies, wherein the sea surface gravity anomaly data is represented as (L i B i , △Hg i ), i = 1, ..., k.

[0261] Furthermore, the third obtaining unit 4 includes:

[0262] The thirteenth obtaining unit is used to obtain ΔTg in the gravity anomaly of the track. i Perform a Fourier transform to obtain the first spectrum;

[0263] The fourteenth obtaining unit is used to multiply the first spectrum by an upward extension factor to obtain a second spectrum, wherein the second spectrum is a spectrum extended upward to the computational surface;

[0264] The fifteenth obtaining unit is used to perform an inverse Fourier transform on the second spectrum to obtain the extended gravity anomaly.

[0265] The foregoing Figure 1 The various variations and specific examples of the gravity anomaly underwater extension method based on upright hexahedral partitioning in Embodiment 1 are also applicable to the gravity anomaly underwater extension device based on upright hexahedral partitioning in this embodiment. Through the foregoing detailed description of the gravity anomaly underwater extension method based on upright hexahedral partitioning, those skilled in the art can clearly understand the implementation method of the gravity anomaly underwater extension device based on upright hexahedral partitioning in this embodiment. Therefore, for the sake of brevity, it will not be described in detail here.

[0266] Example 3

[0267] Based on the same inventive concept as the gravity anomaly underwater extension method based on upright hexahedral subdivision in the foregoing embodiments, the present invention also provides a gravity anomaly underwater extension device based on upright hexahedral subdivision, which stores a computer program that, when executed by a processor, implements the steps of any of the methods of the gravity anomaly underwater extension method based on upright hexahedral subdivision described above.

[0268] Among them, Figure 3 In this document, a bus architecture (represented by bus 300) is used. Bus 300 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 302 and memory represented by memory 304. Bus 300 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 306 provides an interface between bus 300 and receiver 301 and transmitter 303. Receiver 301 and transmitter 303 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium.

[0269] The processor 302 is responsible for managing the bus 300 and general processing, while the memory 304 can be used to store the data used by the processor 302 when performing operations.

[0270] Example 4

[0271] Based on the same inventive concept as the gravity anomaly underwater extension method based on upright hexahedral subdivision in the foregoing embodiments, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, performs the following steps:

[0272] Using an onboard gravimeter, the gravity anomaly of the submersible's trajectory is obtained; the elevation of the upward extension calculation surface is obtained; based on the gravity anomaly of the trajectory and the elevation of the upward extension calculation surface, a vertical hexahedral model is constructed to calculate the seawater gravity anomaly; based on the elevation of the upward extension calculation surface, the gravity anomaly of the trajectory is extended upward to the calculation surface to obtain the extended gravity anomaly; based on the extended gravity anomaly and the seawater gravity anomaly, the upward extension gravity correction value is calculated; the sea surface gravity anomaly is obtained; the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is calculated; an extension threshold is obtained; it is determined whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold; if the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, the upward extension gravity correction value is determined to be the extension gravity value; based on the gravity anomaly of the trajectory and the extension gravity value, the real-time coordinates of the submersible are obtained.

[0273] In practice, when the program is executed by the processor, it can also implement any of the method steps in Embodiment 1.

[0274] The above-described one or more technical solutions in the embodiments of this application have at least one or more of the following technical effects:

[0275] This invention provides an underwater gravity anomaly extrapolation method and apparatus based on upright hexahedral subdivision. The method includes: obtaining the track gravity anomaly of a submersible using an onboard gravimeter; obtaining the elevation of the upward extrapolation calculation surface; constructing an upright hexahedral model based on the track gravity anomaly and the elevation of the upward extrapolation calculation surface, and calculating the seawater gravity anomaly; extrapolating the track gravity anomaly upward to the calculation surface based on the elevation of the upward extrapolation calculation surface, obtaining the extrapolated gravity anomaly; and calculating the upward extrapolation... The process involves: 1) Obtaining a gravity correction value; 2) Obtaining a sea surface gravity anomaly; 3) Calculating the standard deviation of the difference between the sea surface gravity anomaly and the upwardly extended gravity correction value; 4) Obtaining an extension threshold; 5) Determining whether the standard deviation of the difference between the sea surface gravity anomaly and the upwardly extended gravity correction value is less than or equal to the extension threshold; 6) If the standard deviation of the difference between the sea surface gravity anomaly and the upwardly extended gravity correction value is less than or equal to the extension threshold, determining the upwardly extended gravity correction value as an extended gravity value; 7) Obtaining the real-time coordinates of the submersible based on the track gravity anomaly and the extended gravity value. This method addresses the technical problem in the prior art where, when matching track gravity anomaly measurement results with a pre-installed ocean gravity anomaly map, the track gravity anomaly is measured at the depth of the submersible's navigation, while the pre-installed ocean gravity anomaly map is measured at the sea surface, resulting in different elevation planes and thus poor matching performance. The seawater layer is segmented based on the upright hexahedral model, and the gravity anomaly of the track is converted to the sea surface. This enables the matching of the gravity anomaly of the track and the gravity anomaly of the sea surface on the same observation surface, which enhances the positioning accuracy of gravity matching navigation. At the same time, considering the influence of the gravity of the seawater layer, the extrapolation results are more accurate, thereby achieving the technical effect of reducing matching search time and matching speed.

[0276] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0277] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0278] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0279] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0280] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A gravity anomaly underwater extension method based on upright hexahedral subdivision, characterized in that, The method includes: The gravity anomaly in the submersible's trajectory was obtained using the onboard gravimeter; Obtain the elevation of the upward extension calculation surface; Based on the gravity anomaly of the track and the elevation of the upward extension calculation surface, a vertical hexahedron model is constructed to calculate the seawater gravity anomaly. Based on the elevation of the upward extension calculation surface, the track gravity anomaly is extended upward to the calculation surface to obtain the extended gravity anomaly; Calculate the upward extension gravity correction value based on the aforementioned extension gravity anomaly and the aforementioned seawater gravity anomaly; A sea surface gravity anomaly was detected; Calculate the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value; Obtain the extension threshold; Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold; If the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, the upward extension gravity correction value is determined to be the extension gravity value. The real-time coordinates of the submersible are obtained based on the track gravity anomaly and the extended gravity value. If the standard deviation is not less than or equal to the extension threshold, calculate the sum of the difference between the sea surface gravity anomaly and the upward extension gravity correction value and the track gravity anomaly to obtain the second track gravity anomaly. Based on the elevation of the upward extension calculation surface, the gravity anomaly of the second track is extended upward to the calculation surface to obtain the second extended gravity anomaly; Calculate the second upward extension gravity correction value based on the second extension gravity anomaly and the seawater gravity anomaly; Calculate the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value; Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold; If the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold, the second upward extension gravity correction value is determined to be the extension gravity value; The real-time coordinates of the submersible are obtained based on the track gravity anomaly and the second extended gravity value; The step of extending the track gravity anomaly upwards to the calculation surface based on the elevation of the upward extension calculation surface to obtain the extended gravity anomaly includes: For the gravity anomaly in the aforementioned track Perform a Fourier transform to obtain the first spectrum; Multiply the first spectrum by the upward extension factor to obtain the second spectrum, wherein the second spectrum is the spectrum extended upward to the computational surface; Perform an inverse Fourier transform on the second spectrum to obtain the extended gravity anomaly.

2. The method as described in claim 1, characterized in that, The acquisition of gravity anomalies in the submersible's trajectory via an onboard gravimeter includes: Obtain the raw observation data from the shipborne gravimeter, wherein the sequence of the raw observation data is ( L i , B i , TH , ) , i=1,…,p ; in, L i The longitude of the submersible; B i The latitude of the submersible; TH The depth of the submersible is a fixed value. The trajectory of the submersible exhibits a gravity anomaly. p The number of sequences; Detecting the first in the original observation data sequence i Point and the i Missing points between +1 points; Calculate the number of missing points p′ ; Complete the first i Point and the i Missing points between +1 points; The missing points are merged with the original observation data to obtain the track gravity anomaly of the submersible, wherein the track gravity anomaly of the submersible is ( L i , B i , TH , ) i=1,…,k,k=p+p′ .

3. The method as described in claim 2, characterized in that, The process of obtaining the elevation of the upward extension calculation surface includes: Read the sea surface topography map of the area where the submersible is located, wherein the sea surface topography map is represented as follows: （L ii,jj ，B ii,jj ， HM ii,jj ), ii=1,…,m, jj=1,…,n,m The number of horizontal rows. n The number of items in the vertical direction; in, L ii,jj The longitude of the aforementioned sea surface topographic map; B ii,jj The latitude of the aforementioned sea surface topographic map; HM ii,jj The sea surface topography is shown in the aforementioned sea surface topography map; The latitude and longitude of the gravity anomaly of the flight path are projected onto the sea surface topographic map; The longitude and latitude in the sea surface topography map are compared one by one with the longitude and latitude in the track gravity anomaly to filter out the sea surface topography data, wherein the sea surface topography data is ( L i , B i , ) , i=1,…,k, ; Calculate the maximum value of the sea surface topography data; Based on the maximum value of the sea surface topography data, the elevation of the upward extension calculation surface is obtained, wherein the elevation of the upward extension calculation surface is expressed as: .

4. The method as described in claim 1, characterized in that, The step of constructing a vertical hexahedron model based on the gravity anomaly of the navigation track and the elevation of the upwardly extended calculation surface, and calculating the seawater gravity anomaly, includes: A vertical hexahedral model of the seawater layer is constructed, wherein the vertical hexahedral model is based on the depth of the submersible. TH As the bottom surface, based on the aforementioned sea surface topography The top face is the face of the upright hexahedron, and the bottom face of each hexahedron has a side length of . D A square; Based on the upright hexahedral model, the seawater layer is segmented, and the seawater gravity anomaly is calculated.

5. The method as described in claim 1, characterized in that, The acquisition of sea surface gravity anomalies includes: Read the ocean gravity anomaly map of the area where the submersible is located, wherein the ocean gravity anomaly map is represented as follows: （L ii,jj ， B ii,jj ， ), ii=1,…,m, jj=1,…,n,m The number of horizontal rows. n The number of items in the vertical direction; in, L ii,jj The longitude of the aforementioned ocean gravity anomaly map; B ii,jj The latitude of the aforementioned ocean gravity anomaly map; The ocean surface gravity anomaly is shown in the aforementioned ocean gravity anomaly map. Project the latitude and longitude of the track gravity anomaly onto the ocean gravity anomaly map; The longitude and latitude in the ocean gravity anomaly map are compared one by one with the longitude and latitude in the track gravity anomaly to filter out sea surface gravity anomalies. The sea surface gravity anomaly data is represented as (…). L i , B i , ) i=1,…,k .

6. An underwater extension device based on gravity anomaly partitioning using upright hexahedrons, characterized in that, The device includes: The first acquisition unit is used to acquire the gravity anomaly of the submersible's trajectory through an onboard gravimeter; The second obtaining unit is used to obtain the elevation of the upward extension calculation surface; The first calculation unit is used to construct a vertical hexahedron model based on the track gravity anomaly and the elevation of the upward extension calculation surface, and to calculate the seawater gravity anomaly. The third obtaining unit is used to extend the track gravity anomaly upward to the calculation surface according to the elevation of the upward extension calculation surface, and obtain the extended gravity anomaly. The second calculation unit is used to calculate the upward extension gravity correction value based on the extension gravity anomaly and the seawater gravity anomaly. The fourth obtaining unit is used to obtain the sea surface gravity anomaly; The third calculation unit is used to calculate the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value. The fifth obtaining unit is used to obtain the extension threshold; The first judgment unit is used to determine whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold. The first determining unit is configured to determine the upward extension gravity correction value as the extension gravity value if the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold. The sixth obtaining unit is used to obtain the real-time coordinates of the submersible based on the track gravity anomaly and the extended gravity value; The seventh obtaining unit is used to calculate the sum of the difference between the sea surface gravity anomaly and the upward extension gravity correction value and the track gravity anomaly if the standard deviation is not less than or equal to the extension threshold, so as to obtain the second track gravity anomaly. The eighth obtaining unit is used to extend the second track gravity anomaly upward to the calculation surface according to the elevation of the upward extension calculation surface, and obtain the second extended gravity anomaly. The fourth calculation unit is used to calculate the second upward extension gravity correction value based on the second extension gravity anomaly and the seawater gravity anomaly. The fifth calculation unit is used to calculate the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value; The second judgment unit is used to determine whether the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold. The second determining unit is configured to determine the second upward extension gravity correction value as an extension gravity value if the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold. The ninth obtaining unit is used to obtain the real-time coordinates of the submersible based on the track gravity anomaly and the second extended gravity value; The third obtaining unit includes: The thirteenth obtaining unit is used to obtain information from the gravity anomalies in the track. △Tg i Perform a Fourier transform to obtain the first spectrum; The fourteenth obtaining unit is used to multiply the first spectrum by an upward extension factor to obtain a second spectrum, wherein the second spectrum is a spectrum extended upward to the computational surface; The fifteenth obtaining unit is used to perform an inverse Fourier transform on the second spectrum to obtain the extended gravity anomaly.

7. An underwater extension device based on gravity anomalies using upright hexahedral subdivision, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it performs the following steps: The gravity anomaly in the submersible's trajectory was obtained using the onboard gravimeter; Obtain the elevation of the upward extension calculation surface; Based on the gravity anomaly of the track and the elevation of the upward extension calculation surface, a vertical hexahedron model is constructed to calculate the seawater gravity anomaly. Based on the elevation of the upward extension calculation surface, the track gravity anomaly is extended upward to the calculation surface to obtain the extended gravity anomaly; Calculate the upward extension gravity correction value based on the aforementioned extension gravity anomaly and the aforementioned seawater gravity anomaly; A sea surface gravity anomaly was detected; Calculate the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value; Obtain the extension threshold; Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold; If the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, the upward extension gravity correction value is determined to be the extension gravity value. The real-time coordinates of the submersible are obtained based on the track gravity anomaly and the extended gravity value. If the standard deviation is not less than or equal to the extension threshold, calculate the sum of the difference between the sea surface gravity anomaly and the upward extension gravity correction value and the track gravity anomaly to obtain the second track gravity anomaly. Based on the elevation of the upward extension calculation surface, the gravity anomaly of the second track is extended upward to the calculation surface to obtain the second extended gravity anomaly; Calculate the second upward extension gravity correction value based on the second extension gravity anomaly and the seawater gravity anomaly; Calculate the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value; Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold; If the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold, the second upward extension gravity correction value is determined to be the extension gravity value; The real-time coordinates of the submersible are obtained based on the track gravity anomaly and the second extended gravity value; The step of extending the track gravity anomaly upwards to the calculation surface based on the elevation of the upward extension calculation surface to obtain the extended gravity anomaly includes: For the gravity anomaly in the aforementioned track Perform a Fourier transform to obtain the first spectrum; Multiply the first spectrum by the upward extension factor to obtain the second spectrum, wherein the second spectrum is the spectrum extended upward to the computational surface; Perform an inverse Fourier transform on the second spectrum to obtain the extended gravity anomaly.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it performs the following steps: The gravity anomaly in the submersible's trajectory was obtained using the onboard gravimeter; Obtain the elevation of the upward extension calculation surface; Based on the gravity anomaly of the track and the elevation of the upward extension calculation surface, a vertical hexahedron model is constructed to calculate the seawater gravity anomaly. Based on the elevation of the upward extension calculation surface, the track gravity anomaly is extended upward to the calculation surface to obtain the extended gravity anomaly; Calculate the upward extension gravity correction value based on the aforementioned extension gravity anomaly and the aforementioned seawater gravity anomaly; A sea surface gravity anomaly was detected; Calculate the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value; Obtain the continuation threshold; Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold; If the standard deviation of the difference between the sea surface gravity anomaly and the upward extension gravity correction value is less than or equal to the extension threshold, the upward extension gravity correction value is determined to be the extension gravity value. The real-time coordinates of the submersible are obtained based on the track gravity anomaly and the extended gravity value. If the standard deviation is not less than or equal to the extension threshold, calculate the sum of the difference between the sea surface gravity anomaly and the upward extension gravity correction value and the track gravity anomaly to obtain the second track gravity anomaly. Based on the elevation of the upward extension calculation surface, the gravity anomaly of the second track is extended upward to the calculation surface to obtain the second extended gravity anomaly; Calculate the second upward extension gravity correction value based on the second extension gravity anomaly and the seawater gravity anomaly; Calculate the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value; Determine whether the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold; If the standard deviation of the difference between the sea surface gravity anomaly and the second upward extension gravity correction value is less than or equal to the extension threshold, the second upward extension gravity correction value is determined to be the extension gravity value; The real-time coordinates of the submersible are obtained based on the track gravity anomaly and the second extended gravity value; The step of extending the track gravity anomaly upwards to the calculation surface based on the elevation of the upward extension calculation surface to obtain the extended gravity anomaly includes: For the gravity anomaly in the aforementioned track Perform a Fourier transform to obtain the first spectrum; Multiply the first spectrum by the upward extension factor to obtain the second spectrum, wherein the second spectrum is the spectrum extended upward to the computational surface; Perform an inverse Fourier transform on the second spectrum to obtain the extended gravity anomaly.

Images