Modeling method of continuous coverage area of ​​ground using multi-granularity satellite payload model

Abstract

The present invention relates to a modeling and simulation method for the continuous coverage area of ​​the ground during the startup of a multi-granularity satellite payload model. According to different granularity requirements, the payload field of view boundary is discretized in the payload system to generate a set of field of view boundary direction vectors. In combination with the satellite orbit attitude and the payload installation orientation, according to different granularity requirements, the instantaneous ground coverage area of ​​the payload is discretely calculated within the startup time to generate the continuous ground coverage area of ​​the payload. The present invention calculates the instantaneous ground coverage area of ​​the payload through a multi-granularity discretization method, generates the continuous ground coverage area of ​​the payload, and the method is simple and efficient, has good universality, and the calculation process has little correlation with the satellite orbit, satellite attitude, and payload field of view type, and supports the calculation of the continuous ground coverage area of ​​the payload during attitude maneuvers.

Description

Technical Field

[0001] The invention relates to the field of satellite technology, and in particular to a method for modeling a continuous coverage area of ​​the earth using a multi-granularity satellite payload model. Background Art

[0002] The simulation calculation of the continuous ground coverage area of ​​the satellite payload digital model is a basic indicator for analyzing and verifying the ground coverage capability of remote sensing satellites. There are basically two methods for simulating the continuous ground coverage area of ​​the satellite payload digital model. One is to use an analytical method to establish an analytical expression for the continuous ground coverage area of ​​the payload based on the satellite orbit and the payload field of view type, thereby calculating the range of the continuous ground coverage area of ​​the payload. The second is to use a discretized numerical method to discretely calculate the instantaneous ground coverage range of the payload during startup, analyze the left and right boundary points of the instantaneous ground coverage range, and finally form the range of the continuous ground coverage area of ​​the payload. The analytical method has high computational efficiency, but poor universality. It is greatly affected by the orbit type and the payload field of view type, and cannot support the calculation of the continuous ground coverage area of ​​the payload during attitude maneuvers. The discretized numerical method has a large amount of calculation, but good universality, and the calculation process has little correlation with the satellite orbit, satellite attitude, and payload field of view type. Summary of the invention

[0003] The purpose of the present invention is to provide a method for modeling the continuous coverage area of ​​a multi-granularity satellite payload model. The method calculates the instantaneous coverage area of ​​the payload on the ground through a multi-granularity discretization method, and generates the continuous coverage area of ​​the payload on the ground. The method is simple and efficient.

[0004] To achieve the above-mentioned object of the invention, an embodiment of the present invention provides a method for modeling a continuous coverage area of ​​a multi-granularity satellite payload model, comprising:

[0005] S1. According to different granularity requirements, the load field of view boundary is discretized in the load system, and a set of load field of view boundary direction vectors is generated;

[0006] S2. According to the satellite orbit attitude and the payload installation orientation, and in accordance with different granularity requirements, the instantaneous ground coverage area of ​​the payload is discretely calculated within the power-on time to generate the continuous ground coverage area of ​​the payload.

[0007] Preferably, it includes:

[0008] S11. Discrete the conical field of view boundary according to different granularity requirements;

[0009] S12, discretizing the rectangular field of view boundary according to different granularity requirements;

[0010] S13. Discrete the sector ring field of view boundaries according to different granularity requirements.

[0011] Preferably, the S11 includes:

[0012] S111. Determine the unit rotation angle according to the particle size requirement;

[0013] S112, setting the rotation axis vector k to the Z axis of the load system;

[0014] S113, setting the initial value of the rotation angle θ to 0;

[0015] S114, determining whether the current rotation angle θ is less than 2π, if so, calculating the discrete vector of the cone field boundary according to the current rotation angle θ and then entering S115, if not, directly entering S115;

[0016] S115. After the rotation angle θ is increased by one unit angle, the process returns to S114.

[0017] Preferably, in S114, the discrete vector of the conical field of view boundary is calculated based on the Rodriguez rotation formula, and the formula is:

[0018] v rot =cosθv+(1-cosθ)(v×k)k+sinθ(k×v)

[0019] Wherein, v is the vector to be rotated, v = (sin a, θ, cos a), and a is the half angle of the cone field of view.

[0020] Preferably, the S12 includes:

[0021] According to the granularity requirement, the number of discrete points on each side of the rectangular field of view is generated, the field of view boundary direction vector on each side of the rectangular field of view is calculated, and a set of rectangular field of view boundary direction vectors is generated.

[0022] Preferably, the S2 includes:

[0023] S21. Determine the unit time interval according to the granularity requirement;

[0024] S22, determine whether the current time is less than the load shutdown time, if so, calculate the load instantaneous ground coverage area, analyze the left and right boundary points of the instantaneous ground coverage area, generate the load continuous ground coverage area, and then enter S23, if not, directly enter S23;

[0025] S23, increment the current time by a unit time interval and then return to S22.

[0026] Preferably, in S22, calculating the instantaneous coverage area of ​​the load on the ground includes:

[0027] Calculate the transformation matrix from the payload coordinate system to the Earth inertial system based on the satellite's Earth inertial system position and velocity, satellite attitude, and payload installation;

[0028] Traverse the direction vectors of the load field of view boundary, convert all direction vectors to the earth's inertial system, and calculate the earth's inertial system coordinates of the intersection of the load field of view boundary and the earth's surface.

[0029] Preferably, in S22, analyzing the left and right boundary points of the instantaneous ground coverage area includes:

[0030] Traverse the boundary points of the instantaneous ground coverage area of ​​the payload and calculate the angle between the boundary point vector and the normal vector of the satellite orbital plane; when the angle is <π / 2, add the boundary point to the left boundary point set; when the angle is >π / 2, add the boundary point to the right boundary point set; when the angle =π / 2, add the boundary point to both the left and right boundary point sets;

[0031] Traverse the left boundary point set to obtain the boundary point with the largest angle with the satellite orbital plane as the left boundary point of the instantaneous ground coverage area; traverse the right boundary point set to obtain the boundary point with the largest angle with the satellite orbital plane as the right boundary point of the instantaneous ground coverage area;

[0032] If the left boundary point set is empty, traverse the right boundary point set to obtain the boundary points with the smallest and largest angles with the satellite orbital plane, which are used as the left and right boundary points of the instantaneous ground coverage area respectively;

[0033] If the right boundary point set is empty, the left boundary point set is traversed to obtain the boundary points with the largest and smallest angles with the satellite orbital plane, which are used as the left and right boundary points of the instantaneous ground coverage area, respectively.

[0034] Preferably, in S22, generating the range of the continuous coverage area of ​​the load to the ground includes:

[0035] The area enclosed by the left and right boundary points of the instantaneous ground coverage area is the range of the ground continuous coverage area. The earth inertial coordinates of all boundary points are converted into earth fixed coordinates, and then the earth fixed coordinates are converted into geodetic coordinates.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention calculates the instantaneous ground coverage area of ​​the payload to generate the ground continuous coverage area of ​​the payload through a multi-granularity discretization method. The method is simple, efficient, and has good universality. The calculation process has little correlation with the satellite orbit, satellite attitude, and payload field of view type. It supports the calculation of the ground continuous coverage area of ​​the payload during attitude maneuvers and can be applied to satellite payload digital model modeling and simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention 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 invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 The present invention is a flowchart of a method for modeling a continuous coverage area of ​​the earth using a multi-granularity satellite payload model according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The description of the embodiments of this specification should be combined with the corresponding drawings, which should be considered as part of the complete specification. In the drawings, the shape or thickness of the embodiments may be enlarged and indicated for simplification or convenience. Furthermore, the parts of each structure in the drawings will be described separately. It is worth noting that the elements not shown in the drawings or not described in words are in a form known to ordinary technicians in the relevant technical field.

[0041] The description of the embodiments herein and any reference to directions and orientations are only for the convenience of description and are not to be construed as any limitation on the scope of protection of the present invention. The following description of the preferred embodiments may involve combinations of features, which may exist independently or in combination, and the present invention is not particularly limited to the preferred embodiments. The scope of the present invention is defined by the claims.

[0042] like Figure 1 As shown, an embodiment of the present invention provides a method for modeling a continuous coverage area range of a multi-granularity satellite payload model, including:

[0043] S1. According to different granularity requirements, the load field of view boundary is discretized in the load system to generate a set of load field of view boundary direction vectors.

[0044] In this embodiment, step S1 specifically includes:

[0045] S11. Discrete the conical field of view boundary according to different granularity requirements.

[0046] S12. Discrete the rectangular field of view boundary according to different granularity requirements.

[0047] S13. Discrete the sector ring field of view boundaries according to different granularity requirements.

[0048] Wherein, step S11 specifically includes:

[0049] S111. Determine the unit rotation angle according to the granularity requirement.

[0050] S112, setting the rotation axis vector k as the Z axis of the load system.

[0051] S113, setting the initial value of the rotation angle θ to 0.

[0052] S114, determine whether the current rotation angle θ is less than 2π. If so, calculate the discrete vector of the cone field boundary based on the Rodriguez rotation formula and then enter S115. If not, directly enter S115. The calculation formula based on the Rodriguez rotation is:

[0053] v rot =cosθv+(1-cosθ)(v×k)k+sinθ(k×v)

[0054] v is the vector to be rotated, v = (sin a, θ, cos a), and a is the half angle of the cone field of view.

[0055] S115. After the rotation angle θ is increased by one unit angle, the process returns to step S114.

[0056] Wherein, step S12 specifically includes:

[0057] According to the granularity requirement, the number of discrete points on each side of the rectangular field of view is generated, the field of view boundary direction vector on each side of the rectangular field of view is calculated, and a set of rectangular field of view boundary direction vectors is generated.

[0058] S2. According to the satellite orbit attitude and the payload installation orientation, and in accordance with different granularity requirements, the instantaneous ground coverage area of ​​the payload is discretely calculated within the power-on time to generate the continuous ground coverage area of ​​the payload.

[0059] In this embodiment, step S2 specifically includes:

[0060] S21. Determine the unit time interval according to the granularity requirement.

[0061] S22, determine whether the current time is less than the load shutdown time. If so, calculate the load instantaneous ground coverage area, analyze the left and right boundary points of the instantaneous ground coverage area, generate the load continuous ground coverage area, and then enter S23. If not, directly enter S23.

[0062] S23, increment the current time by a unit time interval and then return to S22.

[0063] Among them, in step S22, calculating the instantaneous coverage area of ​​the payload includes: calculating the conversion matrix from the payload coordinate system to the earth inertial system based on the satellite earth inertial system position velocity, satellite attitude, and payload installation. Traversing the direction vectors of the payload field of view boundary, converting all direction vectors to the earth inertial system, and calculating the earth inertial system coordinates of the intersection of the payload field of view boundary and the earth surface.

[0064] Wherein, in step S22, analyzing the left and right boundary points of the instantaneous ground coverage area includes: traversing the boundary points of the instantaneous ground coverage area of ​​the payload, and calculating the angle between the boundary point vector and the normal vector of the satellite orbital plane. When the angle is <π / 2, add the boundary point to the left boundary point set. When the angle is >π / 2, add the boundary point to the right boundary point set. When the angle =π / 2, add the boundary point to the left and right boundary point sets. Traverse the left boundary point set to obtain the boundary point with the largest angle with the satellite orbital plane as the left boundary point of the instantaneous ground coverage area. Traverse the right boundary point set to obtain the boundary point with the largest angle with the satellite orbital plane as the right boundary point of the instantaneous ground coverage area. If the left boundary point set is empty, traverse the right boundary point set to obtain the boundary points with the smallest and largest angles with the satellite orbital plane, which are used as the left and right boundary points of the instantaneous ground coverage area, respectively. If the right boundary point set is empty, the left boundary point set is traversed to obtain the boundary points with the largest and smallest angles with the satellite orbital plane, which are used as the left and right boundary points of the instantaneous ground coverage area, respectively.

[0065] Among them, in step S22, generating the load continuous coverage area range includes: the area enclosed by the left and right boundary points of the instantaneous ground coverage area is the ground continuous coverage area range, converting the ground inertial coordinates of all boundary points into ground fixed coordinates, and then converting the ground fixed coordinates into geodetic coordinates.

[0066] The present invention calculates the instantaneous ground coverage area of ​​the payload to generate the ground continuous coverage area of ​​the payload through a multi-granularity discretization method. The method is simple, efficient, and has good universality. The calculation process has little correlation with the satellite orbit, satellite attitude, and payload field of view type. It supports the calculation of the ground continuous coverage area of ​​the payload during attitude maneuvers and can be applied to satellite payload digital model modeling and simulation.

[0067] According to another aspect of the present invention, an electronic device is also provided, the electronic device comprising one or more processors, one or more memories and one or more computer programs. The processor is connected to the memory, the one or more computer programs are stored in the memory, and when the electronic device is running, the processor executes the one or more computer programs stored in the memory, so that the electronic device performs any method in the technical solution of the above-mentioned embodiment of the present invention.

[0068] According to another aspect of the present invention, a computer-readable storage medium is provided for storing computer instructions. When the computer instructions are executed by a processor, a method as in any one of the technical solutions of the above-mentioned embodiments of the present invention is implemented.

[0069] It should be noted that the present invention may be provided as a method, an apparatus or a computer program product. Therefore, the embodiments of the present invention may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program codes.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for modeling the continuous coverage area of ​​a multi-granularity satellite payload model, characterized in that: include: S1. According to different granularity requirements, the load field of view boundary is discretized in the load system, and a set of load field of view boundary direction vectors is generated; S2. According to the satellite orbit attitude and the payload installation orientation, and in accordance with different granularity requirements, the instantaneous coverage area of ​​the payload on the ground is discretely calculated within the power-on time, and the continuous coverage area of ​​the payload on the ground is generated; Wherein, the S2 includes: S21. Determine the unit time interval according to the granularity requirement; S22, determine whether the current time is less than the load shutdown time, if so, calculate the load instantaneous ground coverage area, analyze the left and right boundary points of the instantaneous ground coverage area, generate the load continuous ground coverage area, and then enter S23, if not, directly enter S23; S23, increment the current time by a unit time interval and then return to S22; In S22, the calculation of the instantaneous ground coverage area of ​​the load includes: Calculate the transformation matrix from the payload coordinate system to the Earth inertial system based on the satellite's Earth inertial system position and velocity, satellite attitude, and payload installation; Traverse the direction vectors of the load field of view boundary, convert all direction vectors to the earth inertial system, and calculate the earth inertial system coordinates of the intersection of the load field of view boundary and the earth's surface; In the S22, analyzing the left and right boundary points of the instantaneous ground coverage area includes: Traverse the boundary points of the instantaneous ground coverage area of ​​the payload and calculate the angle between the boundary point vector and the normal vector of the satellite orbital plane; when the angle is <π / 2, add the boundary point to the left boundary point set; when the angle is >π / 2, add the boundary point to the right boundary point set; when the angle =π / 2, add the boundary point to both the left and right boundary point sets; Traverse the left boundary point set to obtain the boundary point with the largest angle with the satellite orbital plane as the left boundary point of the instantaneous ground coverage area; traverse the right boundary point set to obtain the boundary point with the largest angle with the satellite orbital plane as the right boundary point of the instantaneous ground coverage area; If the left boundary point set is empty, traverse the right boundary point set to obtain the boundary points with the smallest and largest angles with the satellite orbital plane, which are used as the left and right boundary points of the instantaneous ground coverage area respectively; If the right boundary point set is empty, then traverse the left boundary point set to obtain the boundary points with the largest and smallest angles with the satellite orbital plane, which are used as the left and right boundary points of the instantaneous ground coverage area respectively; In S22, generating a continuous coverage area of ​​the load to the ground includes: The area enclosed by the left and right boundary points of the instantaneous ground coverage area is the range of the ground continuous coverage area. The geoinertial coordinates of all boundary points are converted into geodetic coordinates, and then the geodetic coordinates are converted into geodetic coordinates.

2. The method for modeling the continuous coverage area of ​​the ground using a multi-granularity satellite payload model according to claim 1, characterized in that: include: S11. Discrete the conical field of view boundary according to different granularity requirements; S12, discretizing the rectangular field of view boundary according to different granularity requirements; S13. Discrete the sector ring field of view boundaries according to different granularity requirements.

3. The method for modeling the continuous coverage area of ​​the ground using a multi-granularity satellite payload model according to claim 2, characterized in that: The S11 includes: S111. Determine the unit rotation angle according to the particle size requirement; S112, setting the rotation axis vector k to the Z axis of the load system; S113, setting the initial value of the rotation angle θ to 0; S114, determining whether the current rotation angle θ is less than 2π, if so, calculating the discrete vector of the cone field boundary according to the current rotation angle θ and then proceeding to S115, if not, directly proceeding to S115; S115. After the rotation angle θ is increased by one unit angle, the process returns to S114.

4. The method for modeling the continuous coverage area of ​​the ground using a multi-granularity satellite payload model according to claim 3, characterized in that: In S114, the discrete vector of the conical field of view boundary is calculated based on the Rodriguez rotation formula, and the formula is: v rot =cosθv+(1-cosθ)(v×k)k+sinθ(k×v) Wherein, v is the vector to be rotated, v = (sin a, θ, cos a), and a is the half angle of the cone field of view.

5. The method for modeling the continuous coverage area of ​​the ground using a multi-granularity satellite payload model according to claim 2, characterized in that: The S12 includes: According to the granularity requirement, the number of discrete points on each side of the rectangular field of view is generated, the field of view boundary direction vector on each side of the rectangular field of view is calculated, and a set of rectangular field of view boundary direction vectors is generated.

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