Cloud-based parameter calculation methods, devices, electronic equipment, and storage media

Abstract

This invention provides a method, apparatus, electronic device, and storage medium for calculating cloud judgment parameters. The method includes: determining the satellite position vector, solar vector, and satellite attitude matrix in the cloud judgment time inertial frame based on the time interval between the current time and the cloud judgment time; calculating the position information of the ground imaging point corresponding to each pixel after the time interval based on the satellite payload installation information, pixel line-of-sight information, and the satellite position vector and satellite attitude matrix in the cloud judgment time inertial frame; and calculating the cloud judgment parameters for each ground imaging point based on the position information of the ground imaging point corresponding to each pixel after the time interval and the solar vector in the cloud judgment time inertial frame. The cloud judgment parameters include at least one of the following: satellite zenith angle, solar zenith angle, geographic latitude and longitude, and relative azimuth angle. This solution can provide cloud judgment parameters for the cloud judgment process of satellite payloads.

Description

Technical Field

[0001] This invention relates to the field of satellite attitude control technology, and in particular to a cloud judgment parameter calculation method, device, electronic device and storage medium. Background Technology

[0002] Currently, many satellite payloads require the differentiation of cloud images and ground features from existing images; this differentiation is referred to as cloud assessment. Satellite payloads need cloud assessment parameters for specific time periods to perform this assessment. However, there is currently no method for calculating these cloud assessment parameters at each forecast time during the satellite's on-orbit motion. Therefore, there is an urgent need to provide a method for calculating cloud assessment parameters to support the cloud assessment process for satellite payloads. Summary of the Invention

[0003] This invention provides a cloud judgment parameter calculation method, apparatus, electronic device, and storage medium, which can provide cloud judgment parameters for the cloud judgment process of satellite payloads.

[0004] In a first aspect, embodiments of the present invention provide a method for calculating cloud judgment parameters, including:

[0005] Based on the time interval between the current time and the cloud-determined time, determine the satellite position vector, solar vector, and satellite attitude matrix in the cloud-determined time inertial frame;

[0006] Based on the satellite payload installation information, pixel line-of-sight information, and the satellite position vector and satellite attitude matrix under the cloud-based time inertial frame, calculate the position information of the ground imaging point corresponding to each pixel after the time interval;

[0007] Based on the location information of the surface imaging point corresponding to each pixel after the time interval and the solar vector under the cloud judgment time inertia, the cloud judgment parameters of each surface imaging point are calculated; the cloud judgment parameters include at least one of the following: satellite zenith angle, solar zenith angle, geographic latitude and longitude, and relative azimuth angle.

[0008] Secondly, embodiments of the present invention also provide a cloud judgment parameter calculation device, comprising:

[0009] The determining unit is used to determine the satellite position vector, solar vector, and satellite attitude matrix in the cloud-judgment time inertial frame based on the time interval between the current time and the cloud-judgment time.

[0010] The first calculation unit is used to calculate the position information of the ground imaging point corresponding to each pixel after the time interval based on the installation information of the satellite payload, the pixel line-of-sight pointing information, and the satellite position vector and satellite attitude matrix under the cloud judgment time inertial frame.

[0011] The second calculation unit is used to calculate the cloud judgment parameters of each surface imaging point based on the location information of the surface imaging point corresponding to each pixel after the time interval and the solar vector under the cloud judgment time inertia; the cloud judgment parameters include at least one of the following: satellite zenith angle, solar zenith angle, geographic latitude and longitude and relative azimuth angle.

[0012] Thirdly, embodiments of the present invention also provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the method described in any embodiment of this specification.

[0013] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the methods described in any embodiment of this specification.

[0014] This invention provides a method, apparatus, electronic device, and storage medium for calculating cloud judgment parameters. By determining the satellite position vector, solar vector, and satellite attitude matrix in the cloud judgment time inertial frame, the position information of the corresponding surface imaging point for each pixel after a time interval is calculated. Then, cloud judgment parameters for each surface imaging point are calculated based on the position information of each surface imaging point. It is evident that in this scheme, the cloud judgment parameters are predicted and calculated by combining orbit and attitude, resulting in more accurate cloud judgment parameters. Sending the cloud judgment parameters to the payload to assist in cloud judgment calculation improves the accuracy and effectiveness of cloud judgment processing using payload images. Attached Figure Description

[0015] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart of a cloud judgment parameter calculation method provided in an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of the satellite zenith angle and the solar zenith angle provided in an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of a relative azimuth angle provided in an embodiment of the present invention;

[0019] Figure 4 This is a hardware architecture diagram of an electronic device provided in an embodiment of the present invention;

[0020] Figure 5 This is a structural diagram of a cloud judgment parameter calculation device provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] Please refer to Figure 1 This invention provides a method for calculating cloud judgment parameters, the method comprising:

[0023] Step 100: Based on the time interval between the current time and the cloud judgment time, determine the satellite position vector, solar vector, and satellite attitude matrix in the cloud judgment time inertial frame;

[0024] Step 102: Based on the satellite payload installation information, pixel line-of-sight pointing information, and the satellite position vector and satellite attitude matrix under the cloud-based time inertial frame, calculate the position information of the ground imaging point corresponding to each pixel after the time interval.

[0025] Step 104: Calculate the cloud judgment parameters for each surface imaging point based on the location information of the corresponding surface imaging point after the time interval and the solar vector under the cloud judgment time inertia; the cloud judgment parameters include at least one of the following: satellite zenith angle, solar zenith angle, geographic latitude and longitude, and relative azimuth angle.

[0026] In this embodiment of the invention, by determining the satellite position vector, solar vector, and satellite attitude matrix in the cloud-determination time inertial frame, the position information of the corresponding surface imaging point for each pixel after a time interval is calculated. Then, cloud-determination parameters for each surface imaging point are calculated based on the position information of each surface imaging point. It is evident that in this scheme, the cloud-determination parameters are predicted and calculated by combining orbit and attitude, resulting in more accurate cloud-determination parameters. Sending the cloud-determination parameters to the payload to assist in cloud-determination calculation improves the accuracy and effectiveness of cloud-determination processing of the payload image.

[0027] The following description Figure 1 The execution method of each step is shown.

[0028] First, for step 100, based on the time interval between the current time and the cloud judgment time, the satellite position vector, solar vector and satellite attitude matrix in the cloud judgment time inertial frame are determined.

[0029] The cloud assessment time refers to the point in time when the satellite payload performs cloud assessment. In this embodiment of the invention, the cloud assessment time can be any future time point or multiple future time points. By calculating the cloud assessment parameters corresponding to the cloud assessment time, auxiliary calculations are provided for the cloud assessment of the satellite payload. This embodiment uses a future time point as an example to explain the calculation of the cloud assessment parameters for the cloud assessment time.

[0030] After determining the cloud judgment time, the time interval Δt between the current time and the cloud judgment time can be determined.

[0031] Wherein, the satellite position vector in the J2000 inertial frame after Δt is x. DPC y DPC z DPC After Δt, the solar vector in the J2000 inertial frame is S. ixDPC S iyDPC S izDPC The attitude matrix from the inertial frame to the orbital coordinate system after Δt is C. OIDPC .

[0032] In this embodiment of the invention, the satellite attitude matrix C after Δt seconds... TODPC It is related to the satellite's current attitude state, and therefore can be determined in the following way:

[0033] Determine the current attitude state of the satellite;

[0034] If the current attitude state is steady, and a non-zero target attitude such as a yaw angle or a two-dimensional guidance angle is introduced, then the current yaw angle or two-dimensional guidance angle is subtracted from the current attitude state, and the yaw angle or two-dimensional guidance angle after the time interval Δt is compensated to obtain the satellite attitude matrix C at the cloud judgment time. TODPC ;

[0035] If the current attitude state is a maneuvering state, then extrapolate the angular velocity and angular acceleration corresponding to the current attitude state, and compensate the attitude increment after extrapolating the time interval Δt back to the current attitude state to obtain the satellite attitude matrix C at the cloud judgment time. TODPC .

[0036] Then, for step 102, based on the satellite payload installation information, pixel line-of-sight pointing information, and the satellite position vector and satellite attitude matrix under the cloud-based time inertial frame, the position information of the ground imaging point corresponding to each pixel after the time interval is calculated.

[0037] In this embodiment of the invention, the Earth is considered as a standard ellipsoid. Therefore, the position information of the ground imaging point i corresponding to each pixel i includes: a position vector pointing from the Earth's center to that ground imaging point i. And, the position vector from the satellite's center of mass to the ground imaging point i.

[0038] Specifically, the location information of the ground imaging point i corresponding to each pixel i is calculated in the following way (S1-S5):

[0039] S1. Determine the position vector pointing from the Earth's center to the satellite based on the satellite position vector in the cloud-based time inertial frame.

[0040]

[0041] S2. Using the installation position vector in the satellite payload installation information, the installation matrix from the satellite body coordinate system to the payload coordinate system, the position vector of the ground imaging point i in the payload coordinate system, and the satellite attitude matrix, calculate the position vector from the satellite centroid to the pixel i.

[0042] The specific calculation is based on the following formula:

[0043]

[0044] in, Let i be the position vector pointing from the satellite's centroid to pixel i. C is the payload's installation position vector within the satellite's intrinsic structure. PB This is the installation matrix from the satellite body coordinate system to the payload coordinate system. Let i be the position vector of the surface imaging point i in the load coordinate system;

[0045] S3. The sum of the position vector from the Earth's center to the satellite and the position vector from the satellite's centroid to pixel i is used to determine the position vector from the Earth's center to pixel i.

[0046]

[0047] S4. Based on the line-of-sight vector of pixel i in the orbital coordinate system, the line-of-sight vector of pixel i in the inertial frame, and the position vector pointing from the center of the earth to pixel i, calculate the position vector pointing from pixel i to the ground imaging point i and the position vector pointing from the center of the earth to the ground imaging point i.

[0048] Specifically: The position vector pointing from pixel i to ground imaging point i is calculated using the following formula:

[0049] u o,i =C TODPC T ·C PB T ·u p,i

[0050] uI,i =C OIDPC T ·u o,i

[0051]

[0052] A = 1 + d·u I,i (3) 2

[0053]

[0054]

[0055]

[0056]

[0057] Among them, u o,i Let C be the line-of-sight vector of pixel i in the orbital coordinate system. TODPC Let C be the satellite attitude matrix. PB The installation matrix is ​​the one from the satellite body coordinate system to the payload coordinate system. p,i u is the line-of-sight vector of pixel i in the load coordinate system. I,i Let u be the line-of-sight vector of pixel i in the inertial frame. I,i (3) is the third data point of the gaze vector for pixel i; C OIDPC Let a be the attitude matrix from the inertial frame to the orbital coordinate system; e b e ρ represents the semi-major axis and semi-minor axis of the Earth; d, A, B, C, and ρ are intermediate parameters. Let i be the position vector pointing from the Earth's center to pixel i. This is the third data point for the position vector; Let be the position vector pointing from pixel i to ground imaging point i.

[0058] Furthermore, the position vector pointing from the Earth's center to the ground imaging point i for:

[0059]

[0060] S5. The sum of the position vector from the satellite's centroid to pixel i and the position vector from pixel i to ground imaging point i is determined as the position vector from the satellite's centroid to ground imaging point i.

[0061] Position vector from the satellite's center of mass to the ground imaging point i for:

[0062]

[0063] Finally, for step 104, based on the location information of the surface imaging point corresponding to each pixel after the time interval and the solar vector under the cloud judgment time inertia, the cloud judgment parameters of each surface imaging point are calculated; the cloud judgment parameters include at least one of the following: satellite zenith angle, solar zenith angle, geographic latitude and longitude, and relative azimuth angle.

[0064] Please refer to Figure 2 This is a schematic diagram of the satellite zenith angle and the solar zenith angle; Figure 2 In the diagram, point A is the Earth's surface imaging point, and point O is the Earth's center; α is the solar zenith angle, and β is the satellite zenith angle.

[0065] Define the satellite zenith angle as the angle between the line connecting the surface imaging point i to the satellite's center of mass and the line connecting the surface imaging point i to the Earth's center:

[0066]

[0067] Where, β satG,i The zenith angle of the satellite. This is the position vector pointing from the satellite's center of mass to the ground imaging point; This is the position vector pointing from the Earth's center to the imaging point on the ground;

[0068] Define the solar zenith angle as the angle between the line connecting the image point i on the Earth's surface to the Sun and the line connecting the image point i on the Earth's surface to the Earth's center:

[0069]

[0070]

[0071] Where, α sunG,i The zenith angle of the sun. S is the position vector pointing from imaging point i to the sun; ix_DPC S iy_DPC S iz_DPC The solar vector in the inertial frame;

[0072] The formal parameter of the geographic longitude of the surface imaging point i is: L = atan(Y 84 / X 84 );

[0073] The formal parameter of the geographic latitude of the surface imaging point i is: δ = atan(tan(δ) * ) / (1-f E ) 2 );

[0074] in, X 84 Y 84 Z 84 Let i be the position of the surface imaging point i in the WGS84 coordinate system, and let be a constant.

[0075] Please refer to Figure 3 Let O be the Earth's center, A be the image point on the Earth's surface, C be the projection point of the solar vector on Earth, AN be the shortest spherical line connecting A and N (the North Pole) (i.e., the meridian passing through point A), and CN be the shortest spherical line connecting C and N (i.e., the meridian passing through point C). Then, the spherical angle λ from AN rotating from east to west to CN is the relative azimuth angle Δλ of the image point i on the Earth's surface. SunG,i for:

[0076] △λ SunG,i =λ GDPC,i -λ Sun *

[0077] Where, λ GDPC,i λ represents the geographic longitude of the surface imaging point i; Sun * The geographical longitude from the Earth's center to the point where the sun is projected on the Earth's surface can be calculated based on the position of the point where the sun is projected on the Earth's surface in the WGS84 coordinate system.

[0078] In this embodiment of the invention, the calculated cloud judgment parameters are sent to the load-assisted cloud judgment calculation, which improves the accuracy and effectiveness of cloud judgment processing of the load image.

[0079] like Figure 4 , Figure 5 As shown, this embodiment of the invention provides a cloud judgment parameter calculation device. The device embodiment can be implemented through software, hardware, or a combination of both. From a hardware perspective, as... Figure 4 The diagram shown is a hardware architecture diagram of an electronic device containing a cloud-based parameter calculation device, as provided in an embodiment of the present invention. (Except for...) Figure 4 In addition to the processor, memory, network interface, and non-volatile memory shown, the electronic device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, such as... Figure 5 As shown, a device in a logical sense is formed by the CPU of its host electronic device reading the corresponding computer program from non-volatile memory into memory for execution. This embodiment provides a cloud judgment parameter calculation device, including:

[0080] The determining unit 501 is used to determine the satellite position vector, solar vector, and satellite attitude matrix in the cloud-judgment time inertial frame based on the time interval between the current time and the cloud-judgment time.

[0081] The first calculation unit 502 is used to calculate the position information of the ground imaging point corresponding to each pixel after the time interval based on the installation information of the satellite payload, the pixel line-of-sight pointing information, and the satellite position vector and satellite attitude matrix under the cloud judgment time inertial frame.

[0082] The second calculation unit 503 is used to calculate the cloud judgment parameters of each surface imaging point based on the location information of the surface imaging point corresponding to each pixel after the time interval and the solar vector under the cloud judgment time inertia; the cloud judgment parameters include at least one of the following: satellite zenith angle, solar zenith angle, geographic latitude and longitude and relative azimuth angle.

[0083] In one embodiment of the present invention, the determining unit determines the satellite attitude matrix of the cloud judgment time in the following manner:

[0084] Determine the current attitude state of the satellite;

[0085] If the current attitude state is a steady state, then the current yaw angle or two-dimensional guidance angle is subtracted from the current attitude state, and the yaw angle or two-dimensional guidance angle after the time interval is compensated to obtain the satellite attitude matrix at the cloud judgment time.

[0086] If the current attitude state is a maneuvering state, then extrapolate the angular velocity and angular acceleration corresponding to the current attitude state, and compensate the attitude increment after extrapolation of the time interval to the current attitude state to obtain the satellite attitude matrix at the cloud judgment time.

[0087] In one embodiment of the present invention, the location information of the ground imaging point corresponding to each pixel includes: a location vector pointing from the Earth's center to the ground imaging point, and a location vector pointing from the satellite's centroid to the ground imaging point;

[0088] The first calculation unit is specifically used to perform the following calculations:

[0089] The position vector pointing from the Earth's center to the satellite is determined based on the satellite's position vector in the cloud-based time inertial frame.

[0090] Using the installation position vector from the satellite payload installation information, the installation matrix from the satellite body coordinate system to the payload coordinate system, the position vector of the ground imaging point i in the payload coordinate system, and the satellite attitude matrix, calculate the position vector from the satellite's centroid to pixel i.

[0091] The sum of the position vector from the Earth's center to the satellite and the position vector from the satellite's center of mass to pixel i is used to determine the position vector from the Earth's center to pixel i.

[0092] Based on the line-of-sight vector of pixel i in the orbital coordinate system, the line-of-sight vector of pixel i in the inertial frame, and the position vector pointing from the Earth's center to pixel i, calculate the position vector pointing from pixel i to the ground imaging point i and the position vector pointing from the Earth's center to the ground imaging point i.

[0093] The sum of the position vector from the satellite's centroid to pixel i and the position vector from pixel i to ground imaging point i is used to determine the position vector from the satellite's centroid to ground imaging point i.

[0094] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a cloud-based parameter calculation device. In other embodiments of the present invention, a cloud-based parameter calculation device may include more or fewer components than illustrated, or combine some components, or split some components, or arrange different components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0095] The information interaction and execution process between the modules in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.

[0096] This invention also provides an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a cloud judgment parameter calculation method according to any embodiment of this invention.

[0097] This invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform a cloud judgment parameter calculation method according to any embodiment of this invention.

[0098] Specifically, a system or apparatus equipped with a storage medium may be provided, on which software program code implementing the functions of any of the embodiments described above is stored, and the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage medium.

[0099] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute part of the present invention.

[0100] Examples of storage media used to provide program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer via a communication network.

[0101] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system or other components operating on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.

[0102] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.

[0103] 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.

[0104] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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; and these 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 calculating cloud judgment parameters, characterized in that, include: Based on the time interval between the current time and the cloud-determined time, determine the satellite position vector, solar vector, and satellite attitude matrix in the cloud-determined time inertial frame; Based on the satellite payload installation information, pixel line-of-sight information, and the satellite position vector and satellite attitude matrix under the cloud-based time inertial frame, calculate the position information of the ground imaging point corresponding to each pixel after the time interval; Based on the location information of the ground imaging point corresponding to each pixel after the time interval and the solar vector under the cloud judgment time inertia, calculate the cloud judgment parameters of each ground imaging point. The cloud determination parameters include at least one of the following: satellite zenith angle, solar zenith angle, geographic latitude and longitude, and relative azimuth angle.

2. The method according to claim 1, characterized in that, The method for determining the satellite attitude matrix for cloud timing includes: Determine the current attitude state of the satellite; If the current attitude state is a steady state, then the current yaw angle or two-dimensional guidance angle is subtracted from the current attitude state, and the yaw angle or two-dimensional guidance angle after the time interval is compensated to obtain the satellite attitude matrix at the cloud judgment time. If the current attitude state is a maneuvering state, then extrapolate the angular velocity and angular acceleration corresponding to the current attitude state, and compensate the attitude increment after extrapolation of the time interval to the current attitude state to obtain the satellite attitude matrix at the cloud judgment time.

3. The method according to claim 1, characterized in that, The location information of the surface imaging point corresponding to each pixel includes: the location vector from the Earth's center to the surface imaging point, and the location vector from the satellite's centroid to the surface imaging point; The location information of the surface imaging point corresponding to each pixel is calculated in the following way: The position vector pointing from the Earth's center to the satellite is determined based on the satellite's position vector in the cloud-based time inertial frame. Using the installation position vector in the satellite payload installation information, the installation matrix from the satellite body coordinate system to the payload coordinate system, the position vector of the ground imaging point corresponding to the pixel in the payload coordinate system, and the satellite attitude matrix, calculate the position vector from the satellite's centroid to the pixel. The sum of the position vector from the Earth's center to the satellite and the position vector from the satellite's center of mass to the pixel is used to determine the position vector from the Earth's center to the pixel. Based on the line-of-sight vector of the pixel in the orbital coordinate system, the line-of-sight vector of the pixel in the inertial frame, and the position vector pointing from the center of the earth to the pixel, calculate the position vector pointing from the pixel to the corresponding surface imaging point and the position vector pointing from the center of the earth to the corresponding surface imaging point. The sum of the position vector from the satellite's centroid to the pixel and the position vector from the pixel to the corresponding surface imaging point is used to determine the position vector from the satellite's centroid to the corresponding surface imaging point.

4. The method according to claim 3, characterized in that, The position vector pointing from the i-th pixel to the corresponding surface imaging point is calculated using the following formula: in, Let i be the line-of-sight vector of the i-th pixel in the orbital coordinate system. The satellite attitude matrix, This is the installation matrix from the satellite body coordinate system to the payload coordinate system. The line-of-sight vector of the i-th pixel in the load coordinate system; Let be the line-of-sight vector of the i-th pixel in the inertial frame. This is the third data point of the gaze vector for the i-th cell; This represents the attitude matrix from the inertial frame to the orbital coordinate system; , These are the Earth's semi-major and semi-minor axes; A, B, C For intermediate parameters; Let be the position vector pointing from the Earth's center to the i-th pixel. This is the third data point for the position vector; Let be the position vector pointing from the i-th pixel to the corresponding surface imaging point.

5. The method according to claim 3, characterized in that, The calculation of cloud determination parameters for each surface imaging point includes: The satellite zenith angle is defined as the angle between the line connecting the i-th pixel's corresponding surface imaging point and the satellite's centroid, and the line connecting the i-th pixel's corresponding surface imaging point and the Earth's center. in, The zenith angle of the satellite. Let be the position vector pointing from the satellite's centroid to the surface imaging point corresponding to the i-th pixel; Let be the position vector pointing from the Earth's center to the surface imaging point corresponding to the i-th pixel; The solar zenith angle is defined as the angle between the line connecting the i-th pixel's corresponding surface imaging point to the sun, and the line connecting the i-th pixel's corresponding surface imaging point to the Earth's center. in, The zenith angle of the sun. Let be the position vector pointing from the surface imaging point corresponding to the i-th pixel to the sun; , , The solar vector in the inertial frame; The formal parameter for the geographic longitude of the surface imaging point corresponding to the i-th pixel is: ; The formal parameter of the geographic latitude of the surface imaging point corresponding to the i-th pixel is: ; in, , , , Let be the position of the surface imaging point corresponding to the i-th pixel in the WGS84 coordinate system, a constant. ; Let A be the image point on the Earth's surface, C be the projection point of the solar vector on Earth, N be the North Pole, AN be the shortest spherical line connecting A and N, and CN be the shortest spherical line connecting C and N. Then, the spherical angle λ from AN rotating from east to west to CN is the relative azimuth angle of the image point on the Earth's surface corresponding to the i-th pixel. for: in, The geographic longitude of the surface imaging point corresponding to the i-th pixel; It represents the geographical longitude from the Earth's center to the point where the sun projects onto the Earth's surface.

6. A cloud judgment parameter calculation device, characterized in that, include: The determining unit is used to determine the satellite position vector, solar vector, and satellite attitude matrix in the cloud-judgment time inertial frame based on the time interval between the current time and the cloud-judgment time. The first calculation unit is used to calculate the position information of the ground imaging point corresponding to each pixel after the time interval based on the installation information of the satellite payload, the pixel line-of-sight pointing information, and the satellite position vector and satellite attitude matrix under the cloud judgment time inertial frame. The second calculation unit is used to calculate the cloud judgment parameters of each surface imaging point based on the location information of the surface imaging point corresponding to each pixel after the time interval and the solar vector under the cloud judgment time inertia. The cloud determination parameters include at least one of the following: satellite zenith angle, solar zenith angle, geographic latitude and longitude, and relative azimuth angle.

7. The apparatus according to claim 6, characterized in that, The determining unit determines the satellite attitude matrix for the cloud judgment time in the following manner: Determine the current attitude state of the satellite; If the current attitude state is a steady state, then the current yaw angle or two-dimensional guidance angle is subtracted from the current attitude state, and the yaw angle or two-dimensional guidance angle after the time interval is compensated to obtain the satellite attitude matrix at the cloud judgment time. If the current attitude state is a maneuvering state, then extrapolate the angular velocity and angular acceleration corresponding to the current attitude state, and compensate the attitude increment after extrapolation of the time interval to the current attitude state to obtain the satellite attitude matrix at the cloud judgment time.

8. The apparatus according to claim 6, characterized in that, The location information of the surface imaging point corresponding to each pixel includes: the location vector from the Earth's center to the surface imaging point, and the location vector from the satellite's centroid to the surface imaging point; The first calculation unit is specifically used to perform the following calculations: The position vector pointing from the Earth's center to the satellite is determined based on the satellite's position vector in the cloud-based time inertial frame. Using the installation position vector in the satellite payload installation information, the installation matrix from the satellite body coordinate system to the payload coordinate system, the position vector of the ground imaging point corresponding to the pixel in the payload coordinate system, and the satellite attitude matrix, calculate the position vector from the satellite's centroid to the pixel. The sum of the position vector from the Earth's center to the satellite and the position vector from the satellite's center of mass to the pixel is used to determine the position vector from the Earth's center to the pixel. Based on the line-of-sight vector of the pixel in the orbital coordinate system, the line-of-sight vector of the pixel in the inertial frame, and the position vector pointing from the center of the earth to the pixel, calculate the position vector pointing from the pixel to the corresponding surface imaging point and the position vector pointing from the center of the earth to the corresponding surface imaging point. The sum of the position vector from the satellite's centroid to the pixel and the position vector from the pixel to the corresponding surface imaging point is used to determine the position vector from the satellite's centroid to the corresponding surface imaging point.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor, when executing the computer program, implements the method as described in any one of claims 1-5.

10. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the method of any one of claims 1-5.

Images