Method and device for generating resampling grid of earth observation data of polar orbit satellite

Abstract

The invention discloses a resampling grid generation method and device for earth observation data of a polar orbit satellite, and relates to the technical field of polar orbit satellite data processing, and the method comprises the steps: obtaining descending node information and ascending node information based on a circle cutting file; on the basis of the descending node information and a polar orbit satellite orbit forecast file, determining an orbit descending grid; determining an orbit lifting grid based on the ascending node information and a polar orbit satellite orbit forecast file; and on the basis of the determined orbit ascending and descending grids, orbit level resampling of earth observation data is supported and completed, and the purposes of reducing the data volume, improving the effective data quality and meeting the requirement of sea surface wind vector orbit product inversion are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of polar orbit satellite data processing, and in particular to a method and device for generating a resampling grid for polar orbit satellite earth observation data. Background Art

[0002] The wind field measurement radar carried on the Fengyun-3E satellite is an active microwave remote sensor specially used to quantitatively measure the scattering characteristics of the observed surface over a large range from space. The backscattering coefficient measured by the wind field measurement radar in the ocean area is related to the sea surface wind speed and wind direction. Based on the backscattering coefficient measurement data at multiple angles within the same spatial unit, the sea surface wind vector can be calculated through the inversion model.

[0003] The original observations of the wind field measurement radar are in the form of high-resolution slices, and the data volume is very large. In order to improve the data quality and meet the needs of subsequent wind vector orbit product inversion, it is necessary to distribute the slice backscatter coefficients observed by the instrument to the grids in the along-track and cross-track directions of the set spatial resolution, and resample the slice observation data of different incident angles and azimuth angles in the corresponding spatial grid to obtain multi-view data, so as to reduce the data volume, improve the data quality, and meet the needs of wind vector orbit product inversion. Summary of the invention

[0004] The purpose of this application is to provide a method and device for generating a resampling grid for polar orbit satellite earth observation data, which can calculate the resampling grid for polar orbit satellite earth observation data in advance, support the orbital level resampling of earth observation data, reduce the amount of data, improve the quality of effective data, and meet the purpose of inversion of sea surface wind vector orbit products.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a method for generating a resampling grid for polar orbit satellite earth observation data, characterized in that it includes:

[0007] Obtain descending node information and ascending node information based on the circle cutting file; the descending node information includes the descending node time and the descending node longitude; the ascending node information includes the ascending node time and the ascending node longitude; the latitudes of the descending node and the ascending node are both 0°;

[0008] Determining a descending orbit grid based on the descending node information and the polar-orbiting satellite orbit prediction file;

[0009] An ascending grid is determined based on the ascending node information and the polar-orbiting satellite orbit prediction file.

[0010] Optionally, it also includes:

[0011] Based on the orbit-dropping grid and the orbit-raising grid, orbit-level resampling of earth observation data can be supported, thereby completing the orbit inversion of the sea surface wind vector.

[0012] Optionally, determining a descending orbit grid based on the descending node information and a polar-orbiting satellite orbit prediction file includes:

[0013] Add the descending nodes as grid points to the descending orbit grid;

[0014] Determine the descending node moment as the first current moment;

[0015] Determine the first current moment normal vector according to the longitude and latitude of the subsatellite point at the first current moment; the longitude and latitude of the descending node are the longitude and latitude of the subsatellite point at the time of the descending node;

[0016] Obtaining the satellite velocity in the Earth-centered Earth-fixed coordinate system at a first current moment from the polar-orbiting satellite orbit prediction file;

[0017] Determine the ground speed of the sub-satellite point at the first current moment based on the first current moment normal vector and the satellite speed in the Earth-centered Earth-fixed coordinate system at the first current moment;

[0018] Determine the ratio of the grid resolution to the ground speed of the sub-satellite point at the first current time as the current time interval;

[0019] Determine that the difference between the first current moment and the current time interval is the previous moment;

[0020] Obtaining the satellite position in the geocentric inertial coordinate system at the last moment from the polar-orbiting satellite orbit prediction file;

[0021] Based on the satellite position in the geocentric inertial coordinate system at the last moment, determine the longitude and latitude of the sub-satellite point at the last moment;

[0022] The sub-satellite point at the previous moment is used as a grid point and added to the descending orbit grid;

[0023] Take the previous moment as the first current moment, and return to step "determine the normal vector of the first current moment according to the longitude and latitude of the sub-satellite point at the first current moment" until the previous moment is less than the preset moment value, and obtain a grid point sequence along the track direction from the equator to the North Pole.

[0024] Optionally, after obtaining the grid point sequence along the track from the equator to the North Pole, the method further includes:

[0025] Determine the descending node moment as the second current moment;

[0026] Determine the normal vector at the second current moment according to the latitude and longitude of the sub-satellite point at the second current moment;

[0027] Obtain the satellite velocity in the Earth-centered Earth-fixed coordinate system at the second current moment;

[0028] Determine the ground speed of the sub-satellite point at the second current moment based on the second current moment normal vector and the satellite speed in the Earth-centered Earth-fixed coordinate system at the second current moment;

[0029] Determine the ratio of the grid resolution to the ground speed of the sub-satellite point at the second current time as the current time interval;

[0030] Determine the sum of the second current moment and the current time interval as the next moment;

[0031] Obtaining the satellite position in the geocentric inertial coordinate system at the next moment from the polar-orbiting satellite orbit prediction file;

[0032] Based on the satellite position in the geocentric inertial coordinate system at the next moment, determine the latitude and longitude of the sub-satellite point at the next moment;

[0033] The sub-satellite point at the next moment is used as a grid point and added to the descending orbit grid;

[0034] Take the next moment as the second current moment, and return to step "determine the normal vector of the second current moment according to the longitude and latitude of the sub-satellite point at the second current moment" until the next moment is less than the preset moment value, and obtain a grid point sequence along the track direction from the equator to the South Pole.

[0035] Optionally, after obtaining the grid point sequence along the track from the equator to the South Pole, the method further includes:

[0036] Reduce the longitude of the descending node by the preset longitude interval to obtain the longitude of the point equivalent to the eastward descending node;

[0037] Take the eastward descending node equivalent point as the descending node and return to the step "take the descending node as the grid point and add it to the descending orbit grid" until the eastward descending node equivalent point reaches the preset number;

[0038] The longitude of the descending node with the largest longitude is increased by the preset longitude interval to obtain the longitude of the equivalent point of the westward descending node;

[0039] Take the westward descending node equivalent point as the descending node and return to the step "take the descending node as the grid point and add it to the descending orbit grid" until the westward descending node equivalent point reaches the preset number to obtain the descending orbit grid.

[0040] Optionally, the subsatellite point longitude is:

[0041]

[0042] Where lon is the longitude of the subsatellite point; (X, Y, Z) is the satellite position in the Earth-centered Earth-fixed coordinate system;

[0043] The latitude of the subsatellite point is:

[0044]

[0045] Among them, lat is the latitude of the subsatellite point; p is the first intermediate quantity, e is the second intermediate quantity, f is the curvature of the earth, N is the radius of curvature of the y-axis at the subsatellite point, and alt is the satellite altitude;

[0046]

[0047] The normal vector is:

[0048]

[0049] in, is the normal vector;

[0050] The ground speed is:

[0051]

[0052] Among them, U T is the ground speed of the sub-satellite point in the Earth-centered Earth-fixed coordinate system, and U0 is the satellite speed in the Earth-centered Earth-fixed coordinate system.

[0053] Optionally, determining an ascending orbit grid based on the ascending node information and the polar-orbiting satellite orbit prediction file includes:

[0054] Add the ascending node as a grid point to the ascending orbit grid;

[0055] Determine the ascending node moment as the third current moment;

[0056] Determine the third current moment normal vector according to the latitude and longitude of the subsatellite point at the third current moment; the latitude and longitude of the ascending node are the latitude and longitude of the subsatellite point at the ascending node moment;

[0057] Obtain the satellite velocity in the Earth-centered Earth-fixed coordinate system at the third current moment;

[0058] Determine the ground speed of the sub-satellite point at the third current moment based on the normal vector at the third current moment and the satellite speed in the Earth-centered Earth-fixed coordinate system at the third current moment;

[0059] Determine the ratio of the grid resolution to the ground speed of the sub-satellite point at the third current time as the current time interval;

[0060] Determine that the difference between the third current moment and the current time interval is the previous moment;

[0061] Obtaining the satellite position in the geocentric inertial coordinate system at the last moment from the polar-orbiting satellite orbit prediction file;

[0062] Based on the satellite position in the geocentric inertial coordinate system at the last moment, determine the longitude and latitude of the sub-satellite point at the last moment;

[0063] The sub-satellite point at the previous moment is used as a grid point and added to the orbit-raising grid;

[0064] Take the previous moment as the third current moment, and return to step "determine the normal vector of the third current moment according to the longitude and latitude of the sub-satellite point at the third current moment" until the previous moment is less than the preset moment value, and obtain a grid point sequence along the track direction from the equator to the South Pole.

[0065] Optionally, after obtaining the grid point sequence along the track from the equator to the South Pole, the method further includes:

[0066] Determine the ascending node moment as the fourth current moment;

[0067] Determine the normal vector at the fourth current moment according to the latitude and longitude of the sub-satellite point at the fourth current moment;

[0068] Obtain the satellite velocity in the Earth-centered Earth-fixed coordinate system at the fourth current moment;

[0069] Determine the ground speed of the sub-satellite point at the fourth current moment based on the normal vector at the fourth current moment and the satellite speed in the Earth-centered Earth-fixed coordinate system at the fourth current moment;

[0070] Determine the ratio of the grid resolution to the ground speed of the fourth sub-satellite point at the current time as the current time interval;

[0071] Determine the sum of the fourth current moment and the current time interval as the next moment;

[0072] Obtaining the satellite position in the geocentric inertial coordinate system at the next moment from the polar-orbiting satellite orbit prediction file;

[0073] Based on the satellite position in the geocentric inertial coordinate system at the next moment, determine the latitude and longitude of the sub-satellite point at the next moment;

[0074] The sub-satellite point at the next moment is used as a grid point and added to the orbit raising grid;

[0075] The next moment is taken as the fourth current moment, and the step of "determining the normal vector of the fourth current moment according to the longitude and latitude of the sub-satellite point at the fourth current moment" is returned until the next moment is less than the preset moment value, and a grid point sequence along the track direction from the equator to the North Pole is obtained.

[0076] Optionally, after obtaining the grid point sequence along the track from the equator to the South Pole, the method further includes:

[0077] The longitude of the ascending node is reduced by the preset longitude interval to obtain the longitude of the eastward ascending node equivalent point;

[0078] Take the eastward ascending node equivalent point as the ascending node and return to the step "Take the ascending node as a grid point and add it to the ascending orbit grid" until the eastward ascending node equivalent point reaches the preset number;

[0079] The longitude of the ascending node with the largest longitude is increased by the preset longitude interval to obtain the longitude of the equivalent point of the westward ascending node;

[0080] Take the equivalent point of the westward ascending node as the ascending node and return to the step "take the ascending node as a grid point and add it to the ascending orbit grid" until the equivalent point of the westward ascending node reaches a preset number to obtain the ascending orbit grid.

[0081] In a second aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned method for generating a resampling grid for polar-orbiting satellite earth observation data.

[0082] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0083] The present application provides a method and device for generating a resampling grid for earth observation data of a polar-orbiting satellite, which obtains descending node information and ascending node information based on a circle cutting file; determines a descending orbit grid based on the descending node information and a polar-orbiting satellite orbit prediction file; determines an ascending orbit grid based on the ascending node information and a polar-orbiting satellite orbit prediction file; and supports orbit-level resampling of earth observation data based on the determined ascending and descending orbit grids, thereby reducing the amount of data, improving the quality of effective data, and meeting the purpose of inversion of sea surface wind vector orbit products. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0085] Figure 1 This is a flow chart of a method for generating a resampling grid for polar orbit satellite earth observation data in one embodiment of the present application;

[0086] Figure 2 It is a descending orbit grid map with a resolution of 10KM in one embodiment of the present application;

[0087] Figure 3 This is a grid magnification effect diagram in one embodiment of the present application;

[0088] Figure 4 This is a grid diagram of an ascending orbit with a resolution of 10KM in one embodiment of the present application. DETAILED DESCRIPTION

[0089] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0090] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0091] In an exemplary embodiment, Figure 1 , a method for generating a resampling grid for polar orbit satellite earth observation data, comprising:

[0092] Step 101: Obtain descending node information and ascending node information based on the tangent file; the descending node information includes the time of the descending node and the longitude of the descending node. The ascending node information includes the time of the ascending node and the longitude of the ascending node. The latitudes of the descending node and the ascending node are both 0°. The data required for the resampling grid generation method for polar orbit satellite earth observation data in this application include: tangent file, polar orbit satellite orbit prediction file. Among them, the tangent file contains the year, month, day, hour, minute, second and longitude of the descending node, and the year, month, day, hour, minute, second and longitude of the ascending node. The polar orbit satellite orbit prediction file contains day counts, millisecond counts, satellite positions in the geocentric inertial coordinate system, and satellite speeds in the geocentric inertial coordinate system.

[0093] Read the tangent circle file: Get the year, month, day, hour, minute, second and longitude of the descending node, and the year, month, day, hour, minute, second and longitude of the ascending node according to the tangent circle file.

[0094] Read polar-orbit satellite orbit prediction file: Get the day count, millisecond count, satellite position in the geocentric inertial coordinate system, and satellite speed in the geocentric inertial coordinate system according to the polar-orbit satellite orbit prediction file.

[0095] Step 102: Determine a descending orbit grid based on the descending node information and the polar-orbiting satellite orbit prediction file.

[0096] Step 103: Determine an ascending orbit grid based on the ascending node information and the polar-orbiting satellite orbit prediction file.

[0097] Below, taking the descending orbit grid generation process as an example, the resampling grid generation method for polar orbit satellite earth observation data is specifically explained.

[0098] (1) Set the longitude of the descending node in the circle cutting file as the longitude of the starting point, set the latitude of the descending node as the latitude of the starting point, and record the time of the descending node as the starting time; take the starting time as the current time.

[0099] (2) Based on the day count, millisecond count, satellite position and satellite velocity in the geocentric inertial coordinate system obtained from the polar satellite orbit prediction file, the satellite position and velocity in the geocentric inertial coordinate system (ECI) at the current moment are interpolated.

[0100] (3) Satellite position coordinate system conversion: The satellite position (X, Y and Z) in the Earth-centered Earth-fixed coordinate system (ECR) is converted from the current satellite position in the Earth-centered inertial coordinate system.

[0101]

[0102]

[0103] w ie =7.292115e -5 rad / s.

[0104] Where t0 is the time when the two coordinate systems overlap, t is the current time, ECR_P[0], ECR_P[1], ECR_P[2] and ECI_P[0], ECI_P[1], ECI_P[2] represent the satellite positions in the two coordinate systems respectively, and w ie is the angular velocity.

[0105] (4) Calculation of the longitude and latitude of the sub-satellite point: The longitude and latitude of the sub-satellite point in the geodetic coordinate system are obtained from the satellite position in the geocentric, earth-fixed coordinate system.

[0106]

[0107] a=6378137

[0108]

[0109] f = 1 / 298.257

[0110] Where X, Y and Z are the satellite positions in the Earth-centered Earth-fixed coordinate system. Lat, lon, alt are the latitude, longitude and altitude of the sub-satellite point, respectively. p is the first intermediate quantity, e is the second intermediate quantity, f is the curvature of the earth, N is the radius of curvature of the y-axis of the sub-satellite point, and a is the radius of the earth.

[0111] (4) Calculation of the unit normal vector of the sub-satellite point: Calculate the unit normal vector of the sub-satellite point based on the latitude and longitude of the sub-satellite point.

[0112]

[0113] (5) Calculation of satellite velocity in the Earth-centered Earth-fixed coordinate system: Convert the velocity of the Earth-centered inertial coordinate system (ECI) to the velocity of the Earth-centered Earth-fixed coordinate system (ECR). Hereinafter, ECI_V is denoted as U0:

[0114]

[0115] T eci2ecr =ABCD.

[0116] A=R Y (-x p )R X (-y p ).

[0117] Among them, x p and p is the polar coordinate, which can be obtained by interpolating the polar shift value given in the Earth rotation parameter file. ECR_V[0], ECR_V[1] and ECR_V[2] represent the multiple components of the velocity in the Earth-centered Earth-fixed coordinate system. R x , R y , R z is the rotation matrix in three directions.

[0118] B=R z (θ G ).

[0119]

[0120] Among them, T eci2ecr is the conversion matrix, A is the polar motion matrix, B is the rotation matrix, C is the nutation matrix, and D is the precession matrix.

[0121]

[0122] Among them, θ G Greenwich star.

[0123]

[0124] Among them, Δε is the angular nutation.

[0125]

[0126] It is the movement of Huang Jing Zhang.

[0127] Among them, c j ,d j ,n jk are all constants.

[0128]

[0129] Among them, A1 is the moon's mean anomaly angle.

[0130]

[0131] Among them, A2 is the solar anomaly.

[0132]

[0133] Among them, A3 is the moon's mean ascent angle.

[0134]

[0135] Among them, A4 is the sun-moon mean angular moment.

[0136]

[0137] I r =360°.

[0138]

[0139] where T0 is the Julian century number from J2000.0 to t.

[0140] D=R X (-Z p )R Y (θ p )R z (-ξ p ).

[0141]

[0142] (6) Calculate the ground speed of the sub-satellite point.

[0143]

[0144] Among them, U T is the ground speed in the Earth-centered Earth-fixed coordinate system, and U0 is the satellite speed in the Earth-centered Earth-fixed coordinate system.

[0145] (7) Calculate and obtain the descending orbit grid. The grid generation result is as follows: Figures 2 to 4 . Figure 2 and Figure 4 Medium colors indicate land and sea information.

[0146] Set the grid resolution to 10 km.

[0147] A. Along-track grid (from the equator to the North Pole):

[0148] According to the descending node time minus the grid resolution divided by the ground speed, the longitude and latitude of each grid point from the equator to the North Pole are calculated, including:

[0149] Step 102-1: Add the descending node as a grid point to the descending orbit grid.

[0150] Step 102-2: Determine the descending node time as the first current time.

[0151] Step 102-3: Determine the first normal vector at the current time according to the longitude and latitude of the subsatellite point at the first current time. The longitude and latitude of the descending node are the longitude and latitude of the subsatellite point at the time of the descending node.

[0152] Step 102-4: Obtain the satellite velocity in the Earth-centered Earth-fixed coordinate system at the first current moment from the polar-orbiting satellite orbit prediction file.

[0153] Step 102-5: Determine the ground speed of the sub-satellite point at the first current moment based on the normal vector at the first current moment and the satellite speed in the Earth-centered Earth-fixed coordinate system at the first current moment.

[0154] Step 102-6: Determine the ratio of the grid resolution to the ground speed of the sub-satellite point at the first current moment as the current time interval.

[0155] Step 102-7: Determine that the difference between the first current moment and the current time interval is the previous moment.

[0156] Step 102-8: Obtain the satellite position in the geocentric inertial coordinate system at the last moment from the polar-orbiting satellite orbit prediction file.

[0157] Step 102-9: Based on the satellite position in the geocentric inertial coordinate system at the last moment, determine the longitude and latitude of the sub-satellite point at the last moment.

[0158] Step 102-10: Use the sub-satellite point at the previous moment as a grid point and add it to the descending orbit grid.

[0159] Step 102-11: take the previous moment as the first current moment, and return to step 102-3 until the previous moment is less than the preset moment value, to obtain a grid point sequence along the track direction from the equator to the North Pole.

[0160] B. Along-track grid (from the equator to the South Pole):

[0161] The longitude and latitude of each grid point from the equator to the South Pole are calculated based on the descending node time plus the grid resolution divided by the ground speed, including:

[0162] Step 102-12: Determine the descending node time as the second current time.

[0163] Step 102-13: Determine the normal vector at the second current moment according to the longitude and latitude of the sub-satellite point at the second current moment.

[0164] Step 102-14: Obtain the satellite velocity in the Earth-centered Earth-fixed coordinate system at the second current moment.

[0165] Step 102-15: Determine the ground speed of the sub-satellite point at the second current moment based on the normal vector at the second current moment and the satellite speed in the Earth-centered Earth-fixed coordinate system at the second current moment.

[0166] Step 102-16: Determine the ratio of the grid resolution to the ground speed of the sub-satellite point at the second current moment as the current time interval.

[0167] Step 102-17: Determine the sum of the second current moment and the current time interval as the next moment.

[0168] Step 102-18: Obtain the satellite position in the geocentric inertial coordinate system at the next moment from the polar-orbiting satellite orbit prediction file.

[0169] Step 102-19: Based on the satellite position in the geocentric inertial coordinate system at the next moment, determine the longitude and latitude of the sub-satellite point at the next moment.

[0170] Step 102-20: The sub-satellite point at the next moment is used as a grid point and added to the descending orbit grid.

[0171] Step 102-21: take the next moment as the second current moment, and return to step 102-13 until the next moment is less than the preset moment value, to obtain a grid point sequence along the track direction from the equator to the South Pole.

[0172] C. Cross-track direction grid (from west to east):

[0173] When crossing tracks, the time is the same, but the position in the geodetic coordinate system is different. Therefore, the longitude and latitude of each grid point on both sides of the equator to the cross-track direction are calculated based on the current time plus the grid resolution divided by the ground speed, specifically including: reducing the longitude of the descending node by a preset longitude interval to obtain the longitude of the eastward descending node equivalent point. The eastward descending node equivalent point is used as the descending node and returns to step 102-1 until the eastward descending node equivalent point reaches a preset number.

[0174] The present application also provides an application scenario, which applies the above-mentioned method for generating a resampling grid for polar orbit satellite earth observation data. Specifically: the method for generating a resampling grid for polar orbit satellite earth observation data provided in this embodiment can be applied in the inversion scenario of the sea surface wind vector. The inversion scenario of the sea surface wind vector includes an earth observation data acquisition link, an earth observation data preprocessing link, an inversion model building link of the sea surface wind vector and an inversion link of the sea surface wind vector; the method for generating a resampling grid for polar orbit satellite earth observation data provided in this embodiment belongs to the resampling grid generation link in the earth observation data preprocessing link.

[0175] In an exemplary embodiment, a computer device is provided, which may be a server or a terminal, and includes a processor, a memory, an input / output interface (I / O for short) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a method for generating a resampling grid for earth observation data of a polar orbit satellite is implemented.

[0176] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0177] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0178] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0179] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0180] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0181] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0182] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for generating a resampling grid for polar orbit satellite earth observation data, characterized in that: include: Obtain descending node information and ascending node information based on the circle cutting file; the descending node information includes the descending node time and the descending node longitude; the ascending node information includes the ascending node time and the ascending node longitude; the latitudes of the descending node and the ascending node are both 0°; Determining a descending orbit grid based on the descending node information and the polar-orbiting satellite orbit prediction file; An ascending grid is determined based on the ascending node information and the polar-orbiting satellite orbit prediction file.

2. The method for generating a resampling grid for polar orbit satellite earth observation data according to claim 1, characterized in that: Also includes: Based on the orbit-dropping grid and the orbit-raising grid, orbit-level resampling of earth observation data can be supported, thereby completing the orbit inversion of the sea surface wind vector.

3. The method for generating a resampling grid for polar orbit satellite earth observation data according to claim 1, characterized in that: Determining a descending orbit grid based on the descending node information and the polar-orbiting satellite orbit prediction file includes: Add the descending nodes as grid points to the descending orbit grid; Determine the descending node moment as the first current moment; Determine the first current moment normal vector according to the longitude and latitude of the subsatellite point at the first current moment; the longitude and latitude of the descending node are the longitude and latitude of the subsatellite point at the time of the descending node; Obtaining the satellite velocity in the Earth-centered Earth-fixed coordinate system at a first current moment from the polar-orbiting satellite orbit prediction file; Determine the ground speed of the sub-satellite point at the first current moment based on the first current moment normal vector and the satellite speed in the Earth-centered Earth-fixed coordinate system at the first current moment; Determine the ratio of the grid resolution to the ground speed of the sub-satellite point at the first current time as the current time interval; Determine that the difference between the first current moment and the current time interval is the previous moment; Obtaining the satellite position in the geocentric inertial coordinate system at the last moment from the polar-orbiting satellite orbit prediction file; Based on the satellite position in the geocentric inertial coordinate system at the last moment, determine the longitude and latitude of the sub-satellite point at the last moment; The sub-satellite point at the previous moment is used as a grid point and added to the descending orbit grid; The previous moment is taken as the first current moment, and the step of "determining the normal vector of the first current moment according to the longitude and latitude of the sub-satellite point at the first current moment" is returned until the previous moment is less than the preset moment value, and a grid point sequence along the track direction from the equator to the North Pole is obtained.

4. The method for generating a resampling grid for polar orbit satellite earth observation data according to claim 3, characterized in that: After obtaining the grid point sequence along the track from the equator to the North Pole, it also includes: Determine the descending node moment as the second current moment; Determine the normal vector at the second current moment according to the latitude and longitude of the sub-satellite point at the second current moment; Obtain the satellite velocity in the Earth-centered Earth-fixed coordinate system at the second current moment; Determine the ground speed of the sub-satellite point at the second current moment based on the second current moment normal vector and the satellite speed in the Earth-centered Earth-fixed coordinate system at the second current moment; Determine the ratio of the grid resolution to the ground speed of the sub-satellite point at the second current time as the current time interval; Determine the sum of the second current moment and the current time interval as the next moment; Obtaining the satellite position in the geocentric inertial coordinate system at the next moment from the polar-orbiting satellite orbit prediction file; Based on the satellite position in the geocentric inertial coordinate system at the next moment, determine the latitude and longitude of the sub-satellite point at the next moment; The sub-satellite point at the next moment is used as a grid point and added to the descending orbit grid; The next moment is taken as the second current moment, and the step of "determining the normal vector of the second current moment according to the longitude and latitude of the sub-satellite point at the second current moment" is returned until the next moment is less than the preset moment value, and a grid point sequence along the track direction from the equator to the South Pole is obtained.

5. The method for generating a resampling grid for polar orbit satellite earth observation data according to claim 4, characterized in that: After obtaining the grid point sequence along the track from the equator to the South Pole, it also includes: Reduce the longitude of the descending node by the preset longitude interval to obtain the longitude of the point equivalent to the eastward descending node; Take the eastward descending node equivalent point as the descending node and return to step "take the descending node as a grid point and add it to the descending orbit grid" until the eastward descending node equivalent point reaches the preset number; The longitude of the descending node with the largest longitude is increased by the preset longitude interval to obtain the longitude of the equivalent point of the westward descending node; Take the westward descending node equivalent point as the descending node and return to step "take the descending node as a grid point and add it to the descending orbit grid" until the westward descending node equivalent point reaches the preset number to obtain the descending orbit grid.

6. The method for generating a resampling grid for polar orbit satellite earth observation data according to claim 5, characterized in that: The longitude of the subsatellite point is: Where lon is the longitude of the subsatellite point; (X, Y, Z) is the satellite position in the Earth-centered Earth-fixed coordinate system; The latitude of the subsatellite point is: Among them, lat is the latitude of the subsatellite point; p is the first intermediate quantity, e is the second intermediate quantity, f is the curvature of the earth, N is the radius of curvature of the y-axis at the subsatellite point, and alt is the satellite altitude; The normal vector is: in, is the normal vector; The ground speed is: Among them, U T is the ground speed of the sub-satellite point in the Earth-centered Earth-fixed coordinate system, and U0 is the satellite speed in the Earth-centered Earth-fixed coordinate system.

7. The method for generating a resampling grid for polar orbit satellite earth observation data according to claim 1, characterized in that: Determining an ascending orbit grid based on the ascending node information and the polar-orbiting satellite orbit prediction file includes: Add the ascending node as a grid point to the ascending orbit grid; Determine the ascending node moment as the third current moment; Determine the third current moment normal vector according to the latitude and longitude of the subsatellite point at the third current moment; the latitude and longitude of the ascending node are the latitude and longitude of the subsatellite point at the ascending node moment; Obtain the satellite velocity in the Earth-centered Earth-fixed coordinate system at the third current moment; Determine the ground speed of the sub-satellite point at the third current moment based on the normal vector at the third current moment and the satellite speed in the Earth-centered Earth-fixed coordinate system at the third current moment; Determine the ratio of the grid resolution to the ground speed of the sub-satellite point at the third current time as the current time interval; Determine that the difference between the third current moment and the current time interval is the previous moment; Obtaining the satellite position in the geocentric inertial coordinate system at the last moment from the polar-orbiting satellite orbit prediction file; Based on the satellite position in the geocentric inertial coordinate system at the last moment, determine the longitude and latitude of the sub-satellite point at the last moment; The sub-satellite point at the previous moment is used as a grid point and added to the orbit-raising grid; The previous moment is taken as the third current moment, and the step of "determining the normal vector of the third current moment according to the longitude and latitude of the sub-satellite point at the third current moment" is returned until the previous moment is less than the preset moment value, and a grid point sequence along the track direction from the equator to the South Pole is obtained.

8. The method for generating a resampling grid for polar orbit satellite earth observation data according to claim 7, characterized in that: After obtaining the grid point sequence along the track from the equator to the South Pole, it also includes: Determine the ascending node moment as the fourth current moment; Determine the normal vector at the fourth current moment according to the latitude and longitude of the sub-satellite point at the fourth current moment; Obtain the satellite velocity in the Earth-centered Earth-fixed coordinate system at the fourth current moment; Determine the ground speed of the sub-satellite point at the fourth current moment based on the normal vector at the fourth current moment and the satellite speed in the Earth-centered Earth-fixed coordinate system at the fourth current moment; Determine the ratio of the grid resolution to the ground speed of the fourth sub-satellite point at the current time as the current time interval; Determine the sum of the fourth current moment and the current time interval as the next moment; Obtaining the satellite position in the geocentric inertial coordinate system at the next moment from the polar-orbiting satellite orbit prediction file; Based on the satellite position in the geocentric inertial coordinate system at the next moment, determine the latitude and longitude of the sub-satellite point at the next moment; The sub-satellite point at the next moment is used as a grid point and added to the orbit raising grid; The next moment is taken as the fourth current moment, and the step of "determining the normal vector of the fourth current moment according to the latitude and longitude of the sub-satellite point at the fourth current moment" is returned until the next moment is less than the preset moment value, and a grid point sequence along the track direction from the equator to the North Pole is obtained.

9. The method for generating a resampling grid for polar orbit satellite earth observation data according to claim 8, characterized in that: After obtaining the grid point sequence along the track from the equator to the South Pole, it also includes: The longitude of the ascending node is reduced by the preset longitude interval to obtain the longitude of the eastward ascending node equivalent point; Take the eastward ascending node equivalent point as the ascending node and return to step "Take the ascending node as a grid point and add it to the ascending orbit grid" until the eastward ascending node equivalent point reaches the preset number; The longitude of the ascending node with the largest longitude is increased by the preset longitude interval to obtain the longitude of the equivalent point of the westward ascending node; Take the equivalent point of the westward ascending node as the ascending node and return to step "Take the ascending node as a grid point and add it to the ascending orbit grid" until the equivalent point of the westward ascending node reaches the preset number to obtain the ascending orbit grid.

10. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for generating a resampling grid for polar-orbiting satellite earth observation data as described in any one of claims 1 to 9.

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