Method and system for acquiring instantaneous satellite footprint coverage

Abstract

The application provides a satellite instantaneous ground action coverage range acquisition method and system, and relates to the technical field of satellite application. The application firstly acquires the geodetic coordinates of a satellite and the corresponding geocentric angle of the satellite instantaneous ground action coverage range; then determines the latitude interval of the satellite instantaneous ground action coverage range based on the geodetic coordinates and the geocentric angle, and calculates the longitude difference between all boundary points on the boundary of the latitude interval of the coverage range and the current satellite foot point; finally, the geodetic coordinates of each boundary point on the boundary of the satellite instantaneous ground action coverage range are acquired by traversing the latitude interval of the satellite instantaneous ground action coverage range and combining the longitude difference, and the satellite instantaneous ground action coverage range is determined based on the geodetic coordinates of all boundary points. The whole core calculation process of the application is completed in a two-dimensional geodetic coordinate plane, the complex intersection operation in a three-dimensional space is avoided, the engineering implementation steps are simple, and the execution efficiency is higher.

Description

Technical Field

[0001] This invention relates to the field of satellite application technology, and specifically to a method and system for obtaining the instantaneous coverage area of ​​a satellite's Earth-to-ground interaction. Background Technology

[0002] The instantaneous Earth-area coverage of a satellite generally refers to the area of ​​the ground that its sensors can cover at a specific moment during its movement. Spatially, it can be viewed as the area within a certain latitude and longitude range formed by the intersection of the curved surface formed by the sensor's field of view and the Earth's surface. In order for a satellite to perform its intended mission, it is essential to first understand the extent to which the satellite can collect and transmit signals over the Earth during its operation. Therefore, studying the relationship between the satellite's real-time position and its instantaneous Earth-area coverage is of great significance.

[0003] Currently, methods for generating the coverage area of ​​satellite Earth observation include: discretizing and subdividing the conical surface of the sensor's field of view in three-dimensional space, and then obtaining the boundary point set of the ground coverage by finding the intersection points of the rays emanating from the sensor center with the Earth's sphere; establishing sensor observation vectors and solving them simultaneously with the equations of the Earth's ellipsoid to obtain the analytical solution of the coordinates of the boundary points of the coverage area; and solving the boundary of the coverage area by simultaneously solving the spherical equations and conical equations within the Earth-fixed system.

[0004] However, the above methods usually require transformations between multiple coordinate systems and solving quadratic equations, involving complex intersection operations in three-dimensional space. The calculation process is complex and computationally intensive, resulting in low efficiency in generating satellite-to-Earth coverage areas, which is not conducive to the realization of rapid engineering. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a method and system for obtaining the instantaneous Earth-based coverage area of ​​a satellite, solving the problem of low efficiency caused by computational complexity in existing methods for obtaining the instantaneous Earth-based coverage area of ​​a satellite.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] Firstly, this invention proposes a method for obtaining the instantaneous Earth-based coverage area of ​​a satellite, the method comprising:

[0010] Obtain the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-view coverage area;

[0011] Based on the geodetic coordinates and the geocentric angle, determine the latitude range of the instantaneous Earth-to-surface coverage area of ​​the satellite, and calculate the longitude difference between all boundary points on the boundary of the latitude range of the coverage area and the current satellite nadir point;

[0012] Traverse the latitude range of the instantaneous Earth-to-surface coverage area of ​​the satellite, and combine it with the longitude difference to obtain the geodetic coordinates of each boundary point on the boundary of the instantaneous Earth-to-surface coverage area of ​​the satellite. Determine the instantaneous Earth-to-surface coverage area of ​​the satellite based on the geodetic coordinates of all the boundary points.

[0013] Preferably, obtaining the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-on-the-ground coverage area includes: obtaining the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-on-the-ground coverage area based on the satellite's instantaneous position along its orbit and the half-angle of the onboard sensor's field of view, and the steps are as follows:

[0014] S11. Real-time observation data is obtained through the orbit prediction model, and the three-dimensional coordinates of the satellite in the Earth-centered Earth-fixed system are obtained through coordinate transformation;

[0015] S12. Transform the satellite's three-dimensional coordinates in the Earth-centered Earth-fixed system to the geodetic coordinate system to obtain the satellite's geodetic coordinates;

[0016] S13. Determine the geocentric angle corresponding to the instantaneous Earth-to-ground coverage area of ​​the satellite based on the altitude value in the satellite's geodetic coordinates and the half-angle of the field of view of the satellite's onboard sensor.

[0017] Preferably, the step of determining the latitude interval of the satellite's instantaneous Earth-acting coverage area based on the geodetic coordinates and the geocentric angle, and calculating the longitude difference between all boundary points on the latitude interval of the coverage area and the current satellite nadir point includes:

[0018] S21. Based on the latitude coordinates of the satellite's nadir point and the geocentric angle, determine the latitude range of the satellite's instantaneous coverage area, and sample latitude values ​​within this range. The point is used to determine whether there exists a latitude value on the boundary of the coverage area. point;

[0019] S22. If there is a latitude value on the boundary of the coverage area... If the point is a given point, then calculate the longitude difference between that point and the current sub-satellite point.

[0020] S23, Latitude value according to Increment the latitude values ​​and repeat steps S21-S22 above to traverse the coverage latitude interval, storing the latitude values ​​of all sampling points on the coverage boundary. And the corresponding longitude difference.

[0021] Preferably, the method further includes: S4, visualizing the instantaneous Earth-electrode coverage area of ​​the satellite based on the geodetic coordinates of each point on the coverage area boundary; the visualization includes:

[0022] S41. Take sampling points on the boundary of the instantaneous Earth-to-ground coverage area of ​​the satellite in sequence, and transform their coordinates from the geodetic coordinate system to the drawing scene coordinate system according to the size and scale of the visualization scene;

[0023] S42. Within the scene coordinate system, connect all sampling points on the boundary of the coverage area in sequence to form a closed loop curve.

[0024] Preferably, the determination is made regarding whether a latitude value exists at the boundary of the coverage area. The points include: if Then it can be determined that there exists a latitude of on the boundary of the coverage area. The point is calculated using the following formula:

[0025]

[0026] The calculation of the longitude difference between this point and the current nadir point of the satellite includes:

[0027]

[0028] in, Indicates latitude value The difference in longitude between the point and the current sub-satellite point; Indicates the geocentric angle; Indicates latitude value The latitude difference between the point and the current sub-satellite point; This represents the latitude coordinates of the point below the satellite.

[0029] Secondly, the present invention also proposes a system for obtaining the instantaneous Earth-based coverage area of ​​a satellite, the system comprising:

[0030] The geodetic coordinates and geocentric angle acquisition module is used to acquire the geodetic coordinates of the satellite and the geocentric angle corresponding to the instantaneous Earth-view coverage area of ​​the satellite.

[0031] The latitude interval and longitude difference acquisition module is used to determine the latitude interval of the instantaneous Earth-to-surface coverage area of ​​the satellite based on the geodetic coordinates and the geocentric angle, and to calculate the longitude difference between all boundary points on the boundary of the latitude interval of the coverage area and the current satellite nadir point;

[0032] The coverage acquisition module is used to traverse the latitude interval of the satellite's instantaneous Earth-to-surface coverage area, combine it with the longitude difference, obtain the geodetic coordinates of each boundary point on the boundary of the satellite's instantaneous Earth-to-surface coverage area, and determine the satellite's instantaneous Earth-to-surface coverage area based on the geodetic coordinates of all the boundary points.

[0033] Preferably, the geodetic coordinates and geocentric angle acquisition module acquires the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-on-the-ground coverage area by: acquiring the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-on-the-ground coverage area based on the satellite's instantaneous position along its orbit and the half-angle of the onboard sensor's field of view, and the steps are as follows:

[0034] S11. Real-time observation data is obtained through the orbit prediction model, and the three-dimensional coordinates of the satellite in the Earth-centered Earth-fixed system are obtained through coordinate transformation;

[0035] S12. Transform the satellite's three-dimensional coordinates in the Earth-centered Earth-fixed system to the geodetic coordinate system to obtain the satellite's geodetic coordinates;

[0036] S13. Determine the geocentric angle corresponding to the instantaneous Earth-to-ground coverage area of ​​the satellite based on the altitude value in the satellite's geodetic coordinates and the half-angle of the field of view of the satellite's onboard sensor.

[0037] Preferably, the latitude interval and longitude difference acquisition module determines the latitude interval of the satellite's instantaneous Earth-on-the-ground coverage area based on the geodetic coordinates and the geocentric angle, and calculates the longitude difference between all boundary points on the latitude interval of the coverage area and the current satellite nadir point, including:

[0038] S21. Based on the latitude coordinates of the satellite's nadir point and the geocentric angle, determine the latitude range of the satellite's instantaneous coverage area, and sample latitude values ​​within this range. The point is used to determine whether there exists a latitude value on the boundary of the coverage area. point;

[0039] S22. If there is a latitude value on the boundary of the coverage area... If the point is a given point, then calculate the longitude difference between that point and the current sub-satellite point.

[0040] S23, Latitude value according to Increment the latitude values ​​and repeat steps S21-S22 above to traverse the coverage latitude interval, storing the latitude values ​​of all sampling points on the coverage boundary. And the corresponding longitude difference.

[0041] Preferably, the system further includes: a coverage area drawing module, used to visualize the coverage area of ​​the satellite's instantaneous Earth effect based on the geodetic coordinates of each point on the coverage area boundary; the visualization drawing includes:

[0042] S41. Take sampling points on the boundary of the instantaneous Earth-to-ground coverage area of ​​the satellite in sequence, and transform their coordinates from the geodetic coordinate system to the drawing scene coordinate system according to the size and scale of the visualization scene;

[0043] S42. Connect all sampling points on the boundary of the coverage area in sequence within the scene coordinate system to form a closed loop curve.

[0044] Preferably, the determination is made regarding whether a latitude value exists at the boundary of the coverage area. The points include: if Then it can be determined that there exists a latitude of on the boundary of the coverage area. The point is calculated using the following formula:

[0045]

[0046] The calculation of the longitude difference between this point and the current nadir point of the satellite includes:

[0047]

[0048] in, Indicates latitude value The difference in longitude between the point and the current sub-satellite point; Indicates the geocentric angle; Indicates latitude value The latitude difference between the point and the current sub-satellite point; This represents the latitude coordinates of the point below the satellite.

[0049] (III) Beneficial Effects

[0050] This invention provides a method and system for obtaining the instantaneous Earth-based coverage area of ​​a satellite. Compared with existing technologies, it has the following advantages:

[0051] This invention, when determining the instantaneous coverage area of ​​a satellite, first determines the latitudinal range of the coverage area based on the geodetic coordinates of the nadir point and the corresponding geocentric angle of the coverage area. It then calculates the longitude difference between the nadir point and the boundary point of the coverage area, ultimately generating the coordinate set of all sampling points on the boundary of the coverage area. The entire core calculation process of this invention is completed in a two-dimensional geodetic coordinate plane, avoiding complex intersection calculations in three-dimensional space. This simplifies the engineering implementation steps and increases execution efficiency. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is an embodiment diagram of the satellite instantaneous Earth-to-ground coverage acquisition method of the present invention;

[0054] Figure 2 This is a flowchart illustrating the calculation of the geocentric angle corresponding to the coverage area in an embodiment of the present invention;

[0055] Figure 3 This is a flowchart for calculating the longitude difference in an embodiment of the present invention;

[0056] Figure 4 This is a flowchart illustrating the calculation of the geodetic coordinates of each point on the boundary of the coverage area in an embodiment of the present invention;

[0057] Figure 5 A flowchart illustrating the instantaneous Earth-to-ground coverage area of ​​a satellite in an embodiment of the present invention;

[0058] Figure 6 This is a diagram illustrating the instantaneous Earth-to-ground coverage area of ​​a low-latitude satellite, generated using the method described in this embodiment.

[0059] Figure 7 This is a diagram illustrating the instantaneous Earth-to-ground coverage of a high-latitude satellite, generated using the method described in this embodiment. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] This application provides a method and system for obtaining the instantaneous Earth-based coverage area of ​​a satellite, which solves the problem of low efficiency caused by the complexity of existing methods for obtaining the instantaneous Earth-based coverage area of ​​a satellite. It achieves the goal of generating and drawing the instantaneous Earth-based coverage area of ​​a satellite in a simple way for efficient application in practical engineering.

[0062] The technical solution in this application is to solve the above-mentioned technical problems, and the general idea is as follows:

[0063] To address the issue that existing technologies for obtaining the instantaneous Earth-view coverage area of ​​satellites typically require transformations between multiple coordinate systems and solving quadratic equations, resulting in complex intersection operations in three-dimensional space, the proposed solution addresses these problems by performing the core calculations within a two-dimensional geodetic coordinate plane. This avoids the complex intersection operations in three-dimensional space, thereby improving efficiency. The specific method involves: first, determining the latitudinal range of the coverage area; then, calculating the longitude difference between the nadir point and the boundary point of the coverage area; and finally, generating the coordinate set of all sampling points on the boundary of the coverage area.

[0064] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0065] Example 1:

[0066] Firstly, this invention proposes a method for obtaining the instantaneous Earth-based coverage area of ​​a satellite, see [link to relevant documentation]. Figure 1 The method includes:

[0067] S1. Obtain the geodetic coordinates of the satellite and the geocentric angle corresponding to the instantaneous Earth-view coverage area of ​​the satellite;

[0068] S2. Based on the geodetic coordinates and the geocentric angle, determine the latitude range of the instantaneous Earth-to-ground coverage area of ​​the satellite, and calculate the longitude difference between all boundary points on the boundary of the latitude range of the coverage area and the current satellite nadir point;

[0069] S3. Traverse the latitude interval of the instantaneous Earth-to-surface coverage area of ​​the satellite, and combine it with the longitude difference to obtain the geodetic coordinates of each boundary point on the boundary of the instantaneous Earth-to-surface coverage area of ​​the satellite, and determine the instantaneous Earth-to-surface coverage area of ​​the satellite based on the geodetic coordinates of all the boundary points.

[0070] As can be seen, in this embodiment, when solving the instantaneous coverage area of ​​the satellite, based on the geodetic coordinates of the nadir point and the geocentric angle corresponding to the coverage area, it first determines the latitude range of the coverage area, then calculates the longitude difference between the nadir point and the boundary point of the coverage area, and finally generates the coordinate set of all sampling points on the boundary of the coverage area. In this embodiment, the entire core calculation process is completed in a two-dimensional geodetic coordinate plane, avoiding complex intersection calculations in three-dimensional space, resulting in simpler engineering implementation steps and higher execution efficiency.

[0071] The following is in conjunction with the appendix Figures 1-5 The following detailed explanations of the specific steps S1-S3 will be provided to illustrate the implementation process of an embodiment of the present invention. The workflow of the method for obtaining the instantaneous Earth-to-ground coverage area of ​​a satellite in this embodiment mainly includes the following steps:

[0072] S1. Obtain the geodetic coordinates of the satellite and the geocentric angle corresponding to the instantaneous coverage area of ​​the satellite's Earth effect.

[0073] In this embodiment, the satellite's geodetic coordinates and the geocentric angle corresponding to its Earth-acting coverage area are calculated based on the satellite's instantaneous position along its orbit and the half-angle of the field of view of the onboard sensor (general-purpose conic sensor). Specifically, it mainly includes the following steps:

[0074] S11. Real-time observation data is obtained through the orbit prediction model, and the three-dimensional coordinates of the satellite in the Earth-centered Earth-fixed system are obtained through coordinate transformation.

[0075] By analyzing orbit prediction models or receiving real-time observation data, and through coordinate transformation, the three-dimensional coordinates of the satellite in the Earth-centered Earth-fixed system are obtained, denoted as... .

[0076] S12. Transform the satellite's three-dimensional coordinates in the Earth-centered Earth-fixed system to the geodetic coordinate system to obtain the satellite's geodetic coordinates.

[0077] coordinates Transform to the geodetic coordinate system; the transformed geodetic coordinates are as follows: The geodetic coordinate system can be selected as the WGS84 geodetic coordinate system. The specific calculation formula is as follows:

[0078]

[0079] in, The geodetic latitude of the satellite. The geodetic longitude of the satellite. This is the satellite's current altitude. e The first eccentricity of the ellipsoid, ; For the second eccentricity, ; N Let be the radius of curvature of the circle. ; ;in, a The semi-major axis of the WGS84 ellipsoid. b It is the short half-axis.

[0080] S13. Determine the geocentric angle corresponding to the instantaneous Earth-to-ground coverage area of ​​the satellite based on the altitude value in the satellite's geodetic coordinates and the half-angle of the field of view of the satellite's onboard sensor.

[0081] Based on the satellite's current altitude and the known half-angle of the field of view observed by spaceborne sensors Calculate the geocentric angle corresponding to the instantaneous coverage area using the following formula. :

[0082]

[0083] In the formula, angle That is, the angular distance from the satellite's nadir point to the boundary of the coverage area. In practical implementation, a general-purpose conical sensor can be selected as the onboard sensor; This is the average radius of the Earth. For example... Figure 2 As shown, Figure 2 A flowchart for calculating the geocentric angle corresponding to the instantaneous coverage area of ​​a satellite.

[0084] S2. Based on the geodetic coordinates and the geocentric angle, determine the latitude range of the instantaneous Earth-to-ground coverage area of ​​the satellite, and calculate the longitude difference between all boundary points on the latitude range of the coverage area and the current satellite nadir point.

[0085] Determine the latitudinal range spanned by the instantaneous coverage area, and calculate the longitude difference between the coverage area boundary and the current satellite nadir point at the sampling latitude of the range. See also Figure 3 It mainly includes the following steps:

[0086] 1) Based on the latitude coordinates of the satellite's nadir point and the geocentric angle Determine the latitudinal range of the satellite's instantaneous coverage. In practice, to ensure the integrity of the coverage area, the latitude range can be appropriately widened or it can be directly set to... Latitude sampling values ​​within this interval And record the latitude difference Longitude difference Further testing can be performed using the following formula:

[0087]

[0088] like Then it can be determined that there exists a latitude of on the boundary of the coverage area. point.

[0089] 2) If there is a latitude of [latitude value] on the boundary of the coverage area... For the point, the longitude difference between that point and the current sub-satellite point is further calculated. The calculation formula is:

[0090]

[0091] 3) Latitude value Increasing Then repeat step 2 above to store the latitude of the sampling points on the coverage boundary. and the corresponding longitude difference This continues until the traversal of the covered latitude range is complete.

[0092] S3. Traverse the latitude range of the instantaneous Earth-to-surface coverage area of ​​the satellite, and obtain the geodetic coordinates of each boundary point on the boundary of the instantaneous Earth-to-surface coverage area of ​​the satellite by combining the longitude difference. Determine the instantaneous Earth-to-surface coverage area of ​​the satellite based on the geodetic coordinates of all the boundary points.

[0093] See Figure 4 , Figure 4 A flowchart for calculating the geodetic coordinates of points at the coverage boundary is provided. This involves traversing the latitudinal range covered by the instantaneous satellite interaction with the Earth. ,in, , Based on the corresponding longitude difference, calculate the number of points on the coverage boundary east of the nadir point (east is the side with a longitude value greater than the current position) at each sampling latitude in ascending order. i Geodetic coordinates of each sampling point And store them in a queue structure Q. A correction is made when the longitude value crosses 180°, i.e., if >180°, longitude value minus 360°; then calculate the number of longitude values ​​on the coverage boundary west of the nadir point (west side is the side with a longitude value less than the current position) at each sampling latitude in descending order. i Geodetic coordinates of each sampling point And store it in queue Q. Similarly, a correction is made when the longitude value crosses -180°, i.e., if <-180°, longitude value plus 360°. Then save the geodetic coordinates of all sampling points on the boundary of the satellite's instantaneous Earth action coverage area. The range formed by the geodetic coordinates of all these sampling points is the satellite's instantaneous Earth action coverage area.

[0094] To visualize the instantaneous Earth-enveloping coverage area of ​​a satellite, a preferred approach in this embodiment is to visualize and draw the instantaneous Earth-enveloping coverage area using the geodetic coordinates of all sampling points on the boundary of the satellite's instantaneous Earth-enveloping coverage area. In this case, the method further includes:

[0095] S4. Visualize and draw the instantaneous Earth-to-ground coverage area of ​​the satellite based on the geodetic coordinates of each point on the boundary of the coverage area.

[0096] Transform the coordinates of all points on the boundary of the generated instantaneous coverage area to the drawing scene coordinate system, and then visualize the coverage area. See also Figure 5 It mainly includes the following steps:

[0097] S41. Take sampling points on the boundary of the instantaneous Earth-to-ground coverage area of ​​the satellite in sequence, and transform their coordinates from the geodetic coordinate system to the drawing scene coordinate system according to the size and scale of the visualization scene.

[0098] Sequentially retrieve the sampling points on the boundary of the instantaneous Earth-on-satellite effect coverage area stored in queue Q, transform their coordinates from the geodetic coordinate system to the drawing scene coordinate system according to the size and scale of the visualization scene, and save them.

[0099] S42. Within the scene coordinate system, connect all sampling points on the boundary of the coverage area in sequence to form a closed loop curve.

[0100] Within the scene coordinate system, all sampling points on the boundary of the coverage area are sequentially connected to form a closed loop curve, and then the inner area is filled with a certain color value and transparency.

[0101] This completes the entire process of the method for obtaining the instantaneous Earth-to-ground coverage area of ​​a satellite according to the present invention.

[0102] To verify the effectiveness of the method for obtaining the instantaneous Earth-to-ground coverage area of ​​the satellite described in this embodiment, we will compare the rendering effect of the instantaneous Earth-to-ground coverage area of ​​the satellite in this embodiment with the rendering effect of using third-party commercial software in the prior art.

[0103] See Figures 6-7 ,in, Figure 6 This document describes the generation and rendering of the instantaneous Earth-on-the-ground coverage area on a Mercator projection map obtained using the method described in this embodiment when a satellite (Norad number 45183, orbital altitude approximately 550 km, field of view half angle set to 45 degrees) flies over a low-latitude region. Figure 7 This describes the generation and rendering of the instantaneous Earth-on-the-ground coverage area on a Mercator projection map, obtained using the method described in this embodiment, when the satellite flies over high-latitude regions.

[0104] The comparison showed that the coverage area drawn was very consistent with the results generated by third-party commercial software such as STK; when projected onto Mercator maps, satisfactory results were obtained in both low and high latitude regions.

[0105] Furthermore, it has been verified that by using the method of this embodiment to calculate and plot the coverage of 300 satellites in real time during dynamic operation, the graphical interface can maintain a refresh rate of about 25 frames (25 frames is the general standard for smooth real-time interaction), which fully meets the requirements of real-time interaction.

[0106] Example 2:

[0107] Secondly, the present invention also provides a system for obtaining the instantaneous Earth-based coverage area of ​​a satellite, the system comprising:

[0108] The geodetic coordinates and geocentric angle acquisition module is used to acquire the geodetic coordinates of the satellite and the geocentric angle corresponding to the instantaneous Earth-view coverage area of ​​the satellite.

[0109] The latitude interval and longitude difference acquisition module is used to determine the latitude interval of the instantaneous Earth-to-surface coverage area of ​​the satellite based on the geodetic coordinates and the geocentric angle, and to calculate the longitude difference between all boundary points on the boundary of the latitude interval of the coverage area and the current satellite nadir point;

[0110] The coverage acquisition module is used to traverse the latitude interval of the satellite's instantaneous Earth-to-surface coverage area, combine it with the longitude difference, obtain the geodetic coordinates of each boundary point on the boundary of the satellite's instantaneous Earth-to-surface coverage area, and determine the satellite's instantaneous Earth-to-surface coverage area based on the geodetic coordinates of all the boundary points.

[0111] Optionally, the geodetic coordinates and geocentric angle acquisition module acquires the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-on-the-ground coverage area by: acquiring the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-on-the-ground coverage area based on the satellite's instantaneous position along its orbit and the half-angle of the onboard sensor's field of view, and the steps are as follows:

[0112] S11. Real-time observation data is obtained through the orbit prediction model, and the three-dimensional coordinates of the satellite in the Earth-centered Earth-fixed system are obtained through coordinate transformation;

[0113] S12. Transform the satellite's three-dimensional coordinates in the Earth-centered Earth-fixed system to the geodetic coordinate system to obtain the satellite's geodetic coordinates;

[0114] S13. Determine the geocentric angle corresponding to the instantaneous Earth-to-ground coverage area of ​​the satellite based on the altitude value in the satellite's geodetic coordinates and the half-angle of the field of view of the satellite's onboard sensor.

[0115] Optionally, the latitude interval and longitude difference acquisition module determines the latitude interval of the satellite's instantaneous Earth-acting coverage area based on the geodetic coordinates and the geocentric angle, and calculates the longitude difference between all boundary points on the latitude interval of the coverage area and the current satellite nadir point, including:

[0116] S21. Based on the latitude coordinates of the satellite's nadir point and the geocentric angle, determine the latitude range of the satellite's instantaneous coverage area, and sample latitude values ​​within this range. The point is used to determine whether there exists a latitude value on the boundary of the coverage area. point;

[0117] S22. If there is a latitude value on the boundary of the coverage area... If the point is a given point, then calculate the longitude difference between that point and the current sub-satellite point.

[0118] S23, Latitude value according to Increment the latitude values ​​and repeat steps S21-S22 above to traverse the coverage latitude interval, storing the latitude values ​​of all sampling points on the coverage boundary. And the corresponding longitude difference.

[0119] Optionally, the system further includes: a coverage area drawing module, used to visualize the instantaneous Earth-to-surface coverage area of ​​the satellite based on the geodetic coordinates of each point on the coverage area boundary; the visualization drawing includes:

[0120] S41. Take sampling points on the boundary of the instantaneous Earth-to-ground coverage area of ​​the satellite in sequence, and transform their coordinates from the geodetic coordinate system to the drawing scene coordinate system according to the size and scale of the visualization scene;

[0121] S42. Connect all sampling points on the boundary of the coverage area in sequence within the scene coordinate system to form a closed loop curve.

[0122] Optionally, the determination includes checking whether a latitude value exists at the boundary of the coverage area. The points include: if Then it can be determined that there exists a latitude of on the boundary of the coverage area. The point is calculated using the following formula:

[0123]

[0124] The calculation of the longitude difference between this point and the current nadir point of the satellite includes:

[0125]

[0126] in, Indicates latitude value The difference in longitude between the point and the current sub-satellite point; Indicates the geocentric angle; Indicates latitude value The latitude difference between the point and the current sub-satellite point; This represents the latitude coordinates of the point below the satellite.

[0127] It is understood that the satellite instantaneous Earth-area coverage acquisition system provided in this embodiment of the invention corresponds to the satellite instantaneous Earth-area coverage acquisition method described above. The explanations, examples, and beneficial effects of the relevant content can be referred to the corresponding content in the satellite instantaneous Earth-area coverage acquisition method, and will not be repeated here.

[0128] In summary, compared with existing technologies, it has the following beneficial effects:

[0129] This invention, when determining the instantaneous coverage area of ​​a satellite, first determines the latitudinal range of the coverage area based on the geodetic coordinates of the nadir point and the corresponding geocentric angle of the coverage area. It then calculates the longitude difference between the nadir point and the boundary point of the coverage area, ultimately generating the coordinate set of all sampling points on the boundary of the coverage area. The entire core calculation process of this invention is completed in a two-dimensional geodetic coordinate plane, avoiding complex intersection calculations in three-dimensional space. This simplifies the engineering implementation steps and increases execution efficiency.

[0130] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0131] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for obtaining the instantaneous Earth-based coverage area of ​​a satellite, characterized in that, The method includes: Obtain the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-view coverage area; Based on the geodetic coordinates and the geocentric angle, determine the latitude range of the instantaneous Earth-to-surface coverage area of ​​the satellite, and calculate the longitude difference between all boundary points on the boundary of the latitude range of the coverage area and the current satellite nadir point; Traverse the latitude range of the instantaneous Earth-to-surface coverage area of ​​the satellite, and combine it with the longitude difference to obtain the geodetic coordinates of each boundary point on the boundary of the instantaneous Earth-to-surface coverage area of ​​the satellite, and determine the instantaneous Earth-to-surface coverage area of ​​the satellite based on the geodetic coordinates of all the boundary points; The process of determining the latitudinal range of the satellite's instantaneous Earth-view coverage based on the geodetic coordinates and the geocentric angle, and calculating the longitude difference between all boundary points on the boundary of the latitudinal range of the coverage and the current satellite nadir point, includes: S21. Based on the latitude coordinates of the satellite's nadir point and the geocentric angle, determine the latitude range of the satellite's instantaneous coverage area, and sample latitude values ​​within this range. The point is used to determine whether there exists a latitude value on the boundary of the coverage area. point; S22. If there is a latitude value on the boundary of the coverage area... If the point is a given point, then calculate the longitude difference between that point and the current sub-satellite point. S23, Latitude value according to Increment the latitude values ​​and repeat steps S21-S22 above to traverse the coverage latitude interval, storing the latitude values ​​of all sampling points on the coverage boundary. and the corresponding longitude difference; The determination is whether a latitude value exists at the boundary of the coverage area. The points include: if Then it can be determined that there exists a latitude of on the boundary of the coverage area. The point is calculated using the following formula: The calculation of the longitude difference between this point and the current nadir point of the satellite includes: in, Indicates latitude value The difference in longitude between the point and the current sub-satellite point; Indicates the geocentric angle; Indicates latitude value The latitude difference between the point and the current sub-satellite point; This represents the latitude coordinates of the point below the satellite.

2. The method as described in claim 1, characterized in that, The process of obtaining the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-view coverage area includes: obtaining the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-view coverage area based on the satellite's instantaneous position along its orbit and the half-angle of the onboard sensor's field of view, and the steps are as follows: S11. Real-time observation data is obtained through the orbit prediction model, and the three-dimensional coordinates of the satellite in the Earth-centered Earth-fixed system are obtained through coordinate transformation; S12. Transform the satellite's three-dimensional coordinates in the Earth-centered Earth-fixed system to the geodetic coordinate system to obtain the satellite's geodetic coordinates; S13. Determine the geocentric angle corresponding to the instantaneous Earth-to-ground coverage area of ​​the satellite based on the altitude value in the satellite's geodetic coordinates and the half-angle of the field of view of the satellite's onboard sensor.

3. The method as described in claim 1, characterized in that, The method further includes: S4, visualizing the instantaneous Earth-attribute coverage area of ​​the satellite based on the geodetic coordinates of each point on the coverage area boundary; the visualization includes: S41. Take sampling points on the boundary of the instantaneous Earth-to-ground coverage area of ​​the satellite in sequence, and transform their coordinates from the geodetic coordinate system to the drawing scene coordinate system according to the size and scale of the visualization scene; S42. Within the scene coordinate system, connect all sampling points on the boundary of the coverage area in sequence to form a closed loop curve.

4. A system for acquiring the instantaneous Earth-based coverage area of ​​a satellite, characterized in that, The system includes: The geodetic coordinates and geocentric angle acquisition module is used to acquire the geodetic coordinates of the satellite and the geocentric angle corresponding to the instantaneous Earth-view coverage area of ​​the satellite. The latitude interval and longitude difference acquisition module is used to determine the latitude interval of the instantaneous Earth-to-surface coverage area of ​​the satellite based on the geodetic coordinates and the geocentric angle, and to calculate the longitude difference between all boundary points on the boundary of the latitude interval of the coverage area and the current satellite nadir point; The coverage acquisition module is used to traverse the latitude range of the satellite's instantaneous Earth action coverage range, combine the longitude difference, obtain the geodetic coordinates of each boundary point on the boundary of the satellite's instantaneous Earth action coverage range, and determine the satellite's instantaneous Earth action coverage range based on the geodetic coordinates of all the boundary points. The latitude interval and longitude difference acquisition module determines the latitude interval of the satellite's instantaneous Earth-view coverage area based on the geodetic coordinates and the geocentric angle, and calculates the longitude difference between all boundary points on the latitude interval of the coverage area and the current satellite nadir point, including: S21. Based on the latitude coordinates of the satellite's nadir point and the geocentric angle, determine the latitude range of the satellite's instantaneous coverage area, and sample latitude values ​​within this range. The point is used to determine whether there exists a latitude value on the boundary of the coverage area. point; S22. If there is a latitude value on the boundary of the coverage area... If the point is a given point, then calculate the longitude difference between that point and the current sub-satellite point. S23, Latitude value according to Increment the latitude values ​​and repeat steps S21-S22 above to traverse the coverage latitude interval, storing the latitude values ​​of all sampling points on the coverage boundary. and the corresponding longitude difference; The determination is whether a latitude value exists at the boundary of the coverage area. The points include: if Then it can be determined that there exists a latitude of on the boundary of the coverage area. The point is calculated using the following formula: The calculation of the longitude difference between this point and the current nadir point of the satellite includes: in, Indicates latitude value The difference in longitude between the point and the current sub-satellite point; Indicates the geocentric angle; Indicates latitude value The latitude difference between the point and the current sub-satellite point; This represents the latitude coordinates of the point below the satellite.

5. The system as described in claim 4, characterized in that, The geodetic coordinates and geocentric angle acquisition module acquires the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-on-the-ground coverage area by: acquiring the satellite's geodetic coordinates and the geocentric angle corresponding to the satellite's instantaneous Earth-on-the-ground coverage area based on the satellite's instantaneous position along its orbit and the half-angle of the onboard sensor's field of view, and the steps are as follows: S11. Real-time observation data is obtained through the orbit prediction model, and the three-dimensional coordinates of the satellite in the Earth-centered Earth-fixed system are obtained through coordinate transformation; S12. Transform the satellite's three-dimensional coordinates in the Earth-centered Earth-fixed system to the geodetic coordinate system to obtain the satellite's geodetic coordinates; S13. Determine the geocentric angle corresponding to the instantaneous Earth-to-ground coverage area of ​​the satellite based on the altitude value in the satellite's geodetic coordinates and the half-angle of the field of view of the satellite's onboard sensor.

6. The system as described in claim 4, characterized in that, The system further includes: a coverage area drawing module, used to visualize the instantaneous Earth-parallel coverage area of ​​the satellite based on the geodetic coordinates of points on the coverage area boundary; the visualization drawing includes: S41. Take sampling points on the boundary of the instantaneous Earth-to-ground coverage area of ​​the satellite in sequence, and transform their coordinates from the geodetic coordinate system to the drawing scene coordinate system according to the size and scale of the visualization scene; S42. Connect all sampling points on the boundary of the coverage area in sequence within the scene coordinate system to form a closed loop curve.

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