A method for computing on-board guidance attitude of a geosynchronous synthetic aperture radar satellite

Abstract

The application discloses a synchronous orbit synthetic aperture radar satellite on-board guidance attitude calculation method and belongs to the field of satellite attitude control. The method comprises the following steps: calculating the guidance attitude of a satellite at a current time in a yaw-pitch guidance mode; calculating the guidance attitude of a payload beam pointing direction in a pitch-roll guidance mode by using the guidance attitude of the payload beam pointing direction in the yaw-pitch guidance mode; and calculating the final guidance attitude in the pitch-roll guidance process under the constraint of a payload beam installation bias to correct the payload installation bias; and based on the final guidance attitudes at the current time and the last time, the attitude guidance angular rate and the attitude guidance angular acceleration are determined by using a differential calculation mode to combine the orbit parameters to calculate the pitch-roll guidance attitude quaternion at the current time, so that the Doppler frequency of a ground imaging target center point of the satellite is zero. The application can eliminate the influence of a large yaw angle and the influence of a payload installation beam bias and complete satellite attitude guidance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite attitude control, in particular to a synchronous orbit synthetic aperture radar satellite on-board guidance attitude calculation method. BACKGROUND

[0002] The synthetic aperture radar satellite simulates a larger antenna aperture by transmitting and receiving radar pulses in the moving process to realize the imaging of the ground target area. Generally, in order to obtain a higher quality synthetic aperture radar image, the satellite needs to guide the Doppler frequency of the center point of the ground imaging target to zero through the attitude guidance.

[0003] At present, the attitude guidance of the synthetic aperture radar satellite mainly adopts a two-dimensional yaw guidance method, that is, the influence of the earth rotation in the radar imaging process is eliminated through the satellite yaw angle offset, and the influence of the orbit eccentricity is eliminated through the pitch angle offset. In the low-orbit synthetic aperture radar satellite, because the orbit angular velocity of the satellite is much larger than the rotation angular velocity of the earth, the yaw guidance angle of the satellite is small, so it has little influence on the star sensor layout, solar panel driving mechanism control and thermal control design of the satellite. For the synthetic aperture radar satellite in the inclined geosynchronous orbit, the yaw guidance angle reaches ±80° (for example, 20° orbit inclination), which will have a great influence on the star sensor layout, solar panel driving mechanism control and thermal control design of the satellite. Therefore, the traditional yaw-pitch guidance method is difficult to be applied to the on-board guidance attitude control of the synthetic aperture radar satellite in the synchronous orbit.

[0004] Therefore, it is urgent to provide a synchronous orbit synthetic aperture radar satellite on-board guidance attitude calculation method. SUMMARY

[0005] In order to solve the problem that the traditional yaw-pitch guidance method is used for the on-board attitude guidance of the synthetic aperture radar satellite in the synchronous orbit, which will have many adverse effects on the satellite design, the embodiments of the present application provide a synchronous orbit synthetic aperture radar satellite on-board guidance attitude calculation method.

[0006] In one aspect, a synchronous orbit synthetic aperture radar satellite on-board guidance attitude calculation method is provided, and the method comprises:

[0007] The guidance attitude of the satellite in the yaw-pitch guidance mode at the current moment is calculated by using the orbit parameters of the satellite at the current moment.

[0008] The guidance attitude of the satellite in the pitch-rolling guidance mode is calculated by using the guidance attitude of the satellite in the yaw-pitch guidance mode at the current moment, and the final guidance attitude in the pitch-rolling guidance process at the current moment is calculated under the constraint of the satellite load beam installation bias to correct the load installation deviation.

[0009] Based on the final guiding attitude in the pitch-rolling guiding process at the current time and the last time, the attitude guiding angular velocity and the attitude guiding angular acceleration are determined by using a differential calculation method to calculate the satellite pitch-rolling guiding attitude quaternion at the current time in combination with the orbit parameters, so that the Doppler frequency of the ground imaging target center point of the satellite is zero.

[0010] In another aspect, a satellite on-board guiding attitude calculation device for a synthetic aperture radar satellite in a synchronous orbit is provided, which is used to implement the steps of any method embodiment described in the specification, and the device comprises:

[0011] A yaw guiding attitude calculation unit is configured to calculate the guiding attitude of the satellite in a yaw-pitch guiding mode for downloading a payload beam at the current time by using the orbit parameters of the satellite at the current time.

[0012] A pitch guiding attitude calculation unit is configured to calculate the guiding attitude of the satellite in a pitch-rolling guiding mode for downloading a payload beam by using the guiding attitude of the satellite in the yaw-pitch guiding mode for downloading a payload beam at the current time, and to calculate the final guiding attitude in the pitch-rolling guiding process at the current time under the constraint of the satellite payload beam installation bias to correct the payload installation bias.

[0013] A guiding attitude instruction calculation unit is configured to determine the attitude guiding angular velocity and the attitude guiding angular acceleration by using a differential calculation method based on the final guiding attitude in the pitch-rolling guiding process at the current time and the last time, to calculate the satellite pitch-rolling guiding attitude quaternion at the current time in combination with the orbit parameters, so that the Doppler frequency of the ground imaging target center point of the satellite is zero.

[0014] In another aspect, a computer device is provided, which comprises a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program stored on the memory to implement the steps of the above-mentioned method.

[0015] In another aspect, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to implement the steps of the above-mentioned method.

[0016] In another aspect, a computer program product is provided, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the above-mentioned method.

[0017] The technical solution provided by the present application can at least bring the following beneficial effects:

[0018] According to the orbit parameter information of the satellite, the yaw-pitch guiding attitude of the synchronous orbit synthetic aperture radar satellite is converted into a pitch-rolling guiding attitude, so as to eliminate the adverse effect of the large yaw angle of the yaw-pitch guiding on the satellite design, and the load installation deviation is considered, the satellite on-board pitch-rolling guiding attitude is calculated under the constraint of the load beam installation deviation, the influence of the load installation deviation is eliminated, and the guiding attitude control instruction is generated, so that the satellite makes the Doppler frequency of the ground imaging target center point zero through the attitude guiding. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1 is a flow chart of a synchronous orbit synthetic aperture radar satellite on-board guiding attitude calculation method provided by an embodiment of the present application;

[0021] Figure 2 is a guiding attitude of the load beam pointing in the yaw-pitch guiding mode under the satellite load coordinate system provided by an embodiment of the present application;

[0022] Figure 3 is a guiding attitude of the load beam pointing in the pitch-rolling guiding mode under the satellite load coordinate system provided by an embodiment of the present application;

[0023] Figure 4 is the final guiding attitude in the pitch-rolling guiding process under the satellite body coordinate system provided by an embodiment of the present application;

[0024] Figure 5 is a satellite pitch-rolling guiding attitude quaternion provided by an embodiment of the present application;

[0025] Figure 6 is a satellite pitch-rolling guiding attitude angular velocity provided by an embodiment of the present application;

[0026] Figure 7 is a satellite pitch-rolling guiding attitude angular acceleration provided by an embodiment of the present application;

[0027] Figure 8 is a structure diagram of a synchronous orbit synthetic aperture radar satellite on-board guiding attitude calculation device provided by an embodiment of the present application;

[0028] Figure 9 is a hardware architecture diagram of a computer device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0030] The specific implementation of the above concept will be described below.

[0031] Please refer to Figure 1 The method provided by the embodiments of the present application for calculating the on-board guiding attitude of a synthetic aperture radar satellite in a synchronous orbit comprises the following steps.

[0032] Step 100: Calculate the guiding attitude of the satellite in a yaw-pitch guiding mode for pointing the payload beam at the current time according to the orbit parameters of the satellite at the current time.

[0033] Step 102: Calculate the guiding attitude of the satellite in a pitch-roll guiding mode for pointing the payload beam according to the guiding attitude of the satellite in the yaw-pitch guiding mode at the current time, and calculate the final guiding attitude in the pitch-roll guiding process at the current time under the constraint of the offset of the installation of the payload beam, so as to correct the offset of the installation of the payload beam.

[0034] Step 104: Determine the attitude guiding angular rate and the attitude guiding angular acceleration by using a differential calculation method based on the final guiding attitudes in the pitch-roll guiding process at the current time and the previous time, so as to calculate the quaternion of the pitch-roll guiding attitude of the satellite at the current time in combination with the orbit parameters, so that the Doppler frequency of the ground imaging target center point of the satellite is zero.

[0035] In the embodiments of the present application, the yaw-pitch guiding attitude of the synthetic aperture radar satellite in a synchronous orbit is converted into a pitch-roll guiding attitude according to the orbit parameters of the satellite, so as to eliminate the adverse effect of the large yaw angle in the yaw-pitch guiding on the design of the satellite, and the offset of the installation of the payload beam is considered. The satellite on-board pitch-roll guiding attitude under the constraint of the offset of the installation of the payload beam is calculated, so as to eliminate the effect of the offset of the installation of the payload beam, and the guiding attitude control command is generated, so that the satellite makes the Doppler frequency of the ground imaging target center point zero through attitude guiding.

[0036] The execution mode of each step shown in the following description. Figure 1

[0037] For step 100:

[0038] ​In this step, the guidance attitude of the satellite in yaw and pitch guidance mode at the current moment is calculated using the following formula:

[0039]

[0040] In the formula, and These represent the roll guidance angle, pitch guidance angle, and yaw guidance angle of the payload beam pointing in yaw and pitch guidance mode at the current moment, respectively, all in rad. The roll offset angle in yaw and pitch guidance mode set for ground, in rad, ω E The angular velocity of Earth's rotation is expressed in rad / s. For the track inclination angle, Argument of latitude For t k The satellite's current orbital angular velocity, expressed in rad / s. The satellite's current geocentric distance, in kilometers. This represents the rate of change of the satellite's distance from the Earth's center at the current moment, expressed in km / s.

[0041] orbital angular velocity The specific calculation formula is as follows:

[0042]

[0043] Earth-center distance of satellite The specific calculation formula is as follows:

[0044]

[0045] rate of change of satellite's geocentric distance The specific calculation formula is as follows:

[0046]

[0047] In the formula, μ E The gravitational constant has a value of 3.986005 × 10⁻⁶. 5 Unit: km 3 / s 2 , For the semi-major axis of the satellite's orbit, For eccentricity, It is the true near point angle.

[0048] Regarding step 102:

[0049] In some implementations, the step "calculating the guidance attitude of the satellite in pitch and roll guidance mode using the guidance attitude of the satellite in yaw and pitch guidance mode at the current moment" includes:

[0050]

[0051] wherein, and are the roll steering angle, the pitch steering angle and the yaw steering angle of the satellite at the current time t, respectively, in the case of the payload beam pointing in the roll-pitch steering mode, are the roll steering angle, the pitch steering angle and the yaw steering angle of the satellite at the current time t, respectively, in the case of the payload beam pointing in the yaw-pitch steering mode.

[0052] In some embodiments, the step of "calculating the final steering attitude in the roll-pitch steering process at the current time t under the constraint of the payload beam installation bias, to correct the payload installation bias" comprises steps S1-S3:

[0053] S1, determining the transfer matrix from the satellite orbit system to the satellite payload beam installation coordinate system at the current time t, based on the steering attitude of the satellite at the current time t in the roll-pitch steering mode of the payload beam pointing.

[0054] In this step S1, the transfer matrix from the satellite orbit system to the satellite payload beam installation coordinate system at the current time t is calculated by the following formula:

[0055]

[0056] wherein,

[0057]

[0058] wherein, is the transfer matrix from the satellite orbit system to the satellite payload beam installation coordinate system at the current time t, k is the transfer matrix from the satellite orbit system to the satellite payload beam installation coordinate system, is the element in the i-th row and the j-th column of the transfer matrix from the satellite orbit system to the satellite payload beam installation coordinate system, and are the roll steering angle, the pitch steering angle and the yaw steering angle of the satellite at the current time t, respectively, in the case of the payload beam pointing in the roll-pitch steering mode,

[0059] S2, calculating the steering attitude matrix of the satellite from the orbit system to the body system at the current time t, based on the transfer matrix from the satellite orbit system to the satellite payload beam installation coordinate system at the current time t and the transfer matrix from the satellite body system to the satellite payload beam installation coordinate system.

[0060] In this step S2, the steering attitude matrix of the satellite from the orbit system to the body system at the current time t is:

[0061]

[0062] wherein, is the guidance attitude matrix of the satellite from the orbit system to the body system at the current time t, is the element of the guidance attitude matrix in the i-th row and the j-th column, C MB is the transfer matrix from the satellite body system to the satellite payload beam mounting coordinate system, is the final guidance attitude in the current time t k is the transfer matrix from the satellite orbit system to the satellite payload beam mounting coordinate system.

[0063] S3, based on the guidance attitude matrix of the satellite from the orbit system to the body system at the current time t, calculating the final guidance attitude in the process of the pitch-rolling guidance under the constraint of the satellite payload beam mounting bias.

[0064] In this step S3, the final guidance attitude in the process of the pitch-rolling guidance under the constraint of the satellite payload beam mounting bias is calculated by the following way:

[0065]

[0066] wherein, and are the roll guidance angle, the pitch guidance angle and the yaw guidance angle of the final guidance attitude, respectively.

[0067] For step 104:

[0068] In some embodiments, the step of "determining the attitude guidance angle rate and the attitude guidance angle acceleration rate by using the differential calculation method based on the final guidance attitude in the process of the pitch-rolling guidance at the current time and the last time" includes:

[0069] The attitude guidance angle rate is calculated by the following formula:

[0070]

[0071] wherein, is the attitude guidance angle rate at the current time t, is the final guidance attitude in the process of the pitch-rolling guidance at the current time t, k is the final guidance attitude in the process of the pitch-rolling guidance at the current time t, is the final guidance attitude in the process of the pitch-rolling guidance at the last time t-1, k-1 is the final guidance attitude in the process of the pitch-rolling guidance at the last time t-1.

[0072] The attitude guidance angle acceleration rate is calculated by the following formula:

[0073]

[0074] wherein, is the attitude guidance angle acceleration rate, The attitude guidance angular rate at the current moment is the roll guidance angular rate, pitch guidance angular rate, and yaw guidance angular rate. The attitude guidance angular rate at the previous moment is the roll guidance angular rate, pitch guidance angular rate, and yaw guidance angular rate.

[0075] In some implementations, the current satellite pitch and roll guidance attitude quaternion is calculated as shown in steps B1-B4 below:

[0076] B1. Based on the orbital parameters, determine the transfer matrix from the inertial frame to the satellite orbital frame, and combine it with the current satellite's guidance attitude matrix from the orbital frame to its own frame to determine the guidance attitude matrix from the inertial frame to the satellite's own frame.

[0077] In step B1, the transfer matrix from the inertial frame to the satellite orbital frame... It can be represented as:

[0078]

[0079] In the formula, matrix elements The satellite's orbital inclination at the current moment Right ascension of ascending node and latitude angle The calculation yields the following result, specifically expressed as:

[0080]

[0081] Calculate the guidance attitude matrix from the inertial frame to the satellite's own frame:

[0082]

[0083] in, The guidance attitude matrix from the inertial frame to the satellite's own frame. The element in the i-th row and j-th column, This refers to the satellite's guidance attitude matrix from its orbital system to its home system at the current moment, obtained in step 102. This is the transfer matrix from the inertial frame of reference to the satellite orbital frame.

[0084] B2, based on the guidance attitude matrix from the inertial frame to the satellite's own frame, calculates the pitch and roll guidance attitude quaternion of the satellite relative to the inertial frame at the current moment.

[0085] In this step, the current satellite's pitch and roll guidance attitude quaternion relative to the inertial frame is... The calculation formula is:

[0086]

[0087] B3, based on the final guiding attitude in the current moment and the attitude guiding angular rate in the pitch and roll guiding process, determining the pitch and roll guiding attitude angular rate of the satellite relative to the orbit system, and combining the guiding attitude matrix of the satellite from the orbit system to the current system in the current moment, the orbit angular rate of the satellite, determining the pitch and roll guiding attitude angular rate of the satellite relative to the inertial system in the current moment.

[0088] In this step, the pitch and roll guiding attitude angular rate of the satellite relative to the orbit system is:

[0089]

[0090] In the formula, is the attitude guiding angular rate in the current moment, is t k the final guiding attitude in the current moment in the pitch and roll guiding process.

[0091] The pitch and roll guiding attitude angular rate of the satellite relative to the inertial system in the current moment is calculated by the following formula:

[0092]

[0093] In the formula, is the pitch and roll guiding attitude angular rate of the satellite relative to the orbit system, is the guiding attitude matrix of the satellite from the orbit system to the current system in the current moment, is the orbit angular rate of the satellite obtained in step 100.

[0094] B4, based on the final guiding attitude in the current moment, the attitude guiding angular rate and the attitude guiding angular acceleration in the pitch and roll guiding process, determining the pitch and roll guiding attitude angular acceleration of the satellite relative to the orbit system, and combining the pitch and roll guiding attitude angular rate of the satellite relative to the orbit system in the current moment, the guiding attitude matrix of the satellite from the orbit system to the current system and the orbit angular rate of the satellite, determining the pitch and roll guiding attitude angular acceleration of the satellite relative to the inertial system in the current moment.

[0095] In this step, the pitch and roll guiding attitude angular acceleration of the satellite relative to the orbit system The calculation formula is:

[0096]

[0097] In the formula, is the attitude guiding angular rate in the current moment, is t k the final guiding attitude in the current moment in the pitch and roll guiding process, is the attitude guiding angular acceleration.

[0098] the current moment satellite relative to the inertial system's pitch roll guide attitude angular acceleration The calculation formula is:

[0099]

[0100] In the formula, is the satellite relative to the orbit system's pitch roll guide attitude angular velocity, is the satellite's guide attitude matrix from the orbit system to the body system at the current moment, is the satellite's orbit angular velocity obtained in step 100.

[0101] Next, the experimental verification results of the present scheme are described, Figure 2 is the satellite payload coordinate system under the yaw-pitch guide mode The payload beam pointing guide attitude is the roll guide angle, the pitch guide angle and the yaw guide angle in turn. Figure 3 is the satellite payload coordinate system under the pitch roll guide mode The payload beam pointing guide attitude is the roll guide angle, the pitch guide angle and the yaw guide angle in turn. The roll guide angle, the pitch guide angle and the yaw guide angle of Figure 2 and Figure 3 can be compared, and it can be seen that the satellite adopts the pitch roll guide mode, which can effectively reduce the change range of the satellite three-axis attitude angle. Figure 4 is the final guide attitude in the satellite body coordinate system during the pitch roll guide process, which corrects the payload installation deviation, and the roll guide angle, the pitch guide angle and the yaw guide angle are different from those of Figure 3 , which represents the correction effect. Figure 5 , Figure 6 and Figure 7 are the satellite pitch roll guide attitude quaternions, the command angular velocity and the command angular acceleration in turn, and the calculation results show that the related command quaternions, angular velocity and angular acceleration have good continuity, which represents that the satellite attitude control command generated by difference calculation can be directly applied to the satellite attitude guide control, and ensures that the control command parameters are continuous and multi-order derivable.

[0102] Please refer to Figure 8 , the embodiment of the present application provides a synchronous orbit synthetic aperture radar satellite on-board guide attitude calculation device, which is used for realizing the steps of any method embodiment in the specification, and the device comprises:

[0103] The yaw guide attitude calculation unit 801 is used for calculating the satellite's guide attitude in the yaw-pitch guide mode under the payload beam pointing at the current moment by using the orbit parameters of the satellite at the current moment.

[0104] The pitch guide attitude calculation unit 802 is configured to calculate a guide attitude of the satellite in a pitch-rolling guide mode by using a guide attitude of the satellite in a yaw-pitch guide mode at a current time, and calculate a final guide attitude in the pitch-rolling guide process at the current time under a constraint of a load mounting bias of the satellite, so as to correct the load mounting bias.

[0105] The guide attitude instruction calculation unit 803 is configured to determine an attitude guide angular rate and an attitude guide angular acceleration by using a differential calculation mode based on the final guide attitude in the pitch-rolling guide process at the current time and a previous time, so as to calculate a quaternion of the pitch-rolling guide attitude of the satellite at the current time in combination with an orbit parameter, so that a Doppler frequency of a ground imaging target center point of the satellite is zero.

[0106] It should be noted that the on-board guide attitude calculation device of the synthetic aperture radar satellite in the synchronous orbit provided in the above embodiment is only exemplified by the division of the above functional units, and in actual application, the above functions can be distributed to be completed by different functional units according to needs, that is, the internal structure of the device is divided into different functional units to complete all or part of the functions described above. In addition, the device embodiment and the method embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be described here.

[0107] Embodiments of the present application also provide a computer device, which refers to Figure 9 The computer device includes a processor and a memory, and the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to implement the on-board guide attitude calculation method of the synthetic aperture radar satellite in the synchronous orbit provided in each method embodiment.

[0108] Embodiments of the present application also provide a computer readable storage medium, which stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to implement the on-board guide attitude calculation method of the synthetic aperture radar satellite in the synchronous orbit provided in each method embodiment.

[0109] Embodiments of the present application also provide a computer program product, which includes a computer program, and the processor of the computer device reads the computer program from the computer readable storage medium, and the processor executes the computer program, so that the computer device executes the on-board guide attitude calculation method of the synthetic aperture radar satellite in the synchronous orbit in any of the above embodiments.

[0110] For ease of description, the above system or apparatus is described in various modules or units respectively in terms of functions. Of course, in the implementation of the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0111] From the above description of the embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary universal hardware platforms. Based on such an understanding, the technical solutions of the present application can be embodied in the form of a software product, and the computer software product can be stored in a storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods of the various embodiments or some parts of the embodiments.

[0112] Finally, it should be noted that in this document, relational terms such as first and second and third and fourth, and the like can merely be used to distinguish one entity or action from another, without necessarily requiring or implying any actual relationship or order between or among the entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0113] The above is only the preferred embodiment of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for calculating the on-board guidance attitude of a synchronous orbit synthetic aperture radar satellite, characterized in that, include: Calculate the guidance attitude of the satellite in yaw and pitch guidance mode at the current moment using the satellite's orbital parameters at the current moment; The guidance attitude of the payload beam in the current yaw and pitch guidance mode is used to calculate the guidance attitude of the payload beam in the current pitch and roll guidance mode. Under the satellite payload beam installation offset constraint, the final guidance attitude in the current pitch and roll guidance process is calculated to correct the payload installation deviation. Based on the final guidance attitude during the pitch and roll guidance process at the current and previous moments, the attitude guidance angular rate and attitude guidance angular acceleration are determined using differential calculation. Combined with the orbital parameters, the quaternion of the satellite's pitch and roll guidance attitude at the current moment is calculated, so that the Doppler frequency of the satellite's ground imaging target center point is zero. Calculate the satellite's payload beam pointing attitude in pitch and roll guidance mode using the current satellite's guidance attitude in yaw and pitch guidance mode, including: In the formula, , and These represent the roll guidance angle, pitch guidance angle, and yaw guidance angle of the payload beam pointing to the satellite at the current moment in pitch-roll guidance mode. , , These are the roll guidance angle, pitch guidance angle, and yaw guidance angle of the payload beam pointing to the satellite in yaw and pitch guidance mode at the current moment; Under the satellite payload beam installation offset constraint, calculate the final guidance attitude during the current pitch and roll guidance process to correct the payload installation deviation, including: Based on the current guidance attitude of the satellite in pitch and roll guidance mode, determine the transfer matrix from the satellite orbit system to the satellite payload beam installation coordinate system at the current moment; Based on the current transition matrix from the satellite orbital system to the satellite payload beam installation coordinate system and the current transition matrix from the satellite body system to the satellite payload beam installation coordinate system, calculate the current satellite's guidance attitude matrix from the orbital system to the body system. Based on the current satellite's guidance attitude matrix from the orbital system to the home system, calculate the final guidance attitude during the pitch and roll guidance process under the satellite payload beam installation offset constraint; The final guidance attitude during pitch and roll guidance under satellite payload beam installation offset constraints is calculated as follows: The current satellite's guidance attitude matrix from its orbital system to its home system is: in, This is the current satellite's guidance attitude matrix from its orbital system to its home system. To guide the element in the i-th row and j-th column of the attitude matrix, C MB This is the transfer matrix from the satellite's own coordinate system to the satellite payload beam installation coordinate system. For the current moment The transfer matrix from the satellite orbital system to the satellite payload beam installation coordinate system; The final guidance attitude is calculated using the following formula: In the formula, , and These are the roll guidance angle, pitch guidance angle, and yaw guidance angle for the final guidance attitude.

2. The method as described in claim 1, characterized in that, The transition matrix from the satellite orbital system to the satellite payload beam installation coordinate system at the current moment is calculated using the following formula: in, In the formula, For the current moment The transfer matrix from the satellite orbital system to the satellite payload beam installation coordinate system. The element in the i-th row and j-th column of the transfer matrix from the satellite orbital system to the satellite payload beam installation coordinate system. , and These are the roll guidance angle, pitch guidance angle, and yaw guidance angle of the payload beam pointing to the satellite at the current moment in the pitch and roll guidance mode.

3. The method as described in claim 1, characterized in that, The current satellite pitch and roll guidance attitude quaternion is calculated as follows: Based on the orbital parameters, the transfer matrix from the inertial frame to the satellite orbital frame is determined, and combined with the current satellite's guidance attitude matrix from the orbital frame to its own frame, the guidance attitude matrix from the inertial frame to the satellite's own frame is determined. Based on the guidance attitude matrix from the inertial frame to the satellite's own frame, calculate the pitch and roll guidance attitude quaternion of the satellite relative to the inertial frame at the current moment; Based on the final guidance attitude and the attitude guidance angular rate during the current pitch roll guidance process, the pitch roll guidance attitude angular velocity of the satellite relative to the orbital system is determined. Combined with the guidance attitude matrix of the satellite from the orbital system to the home system and the satellite's orbital angular velocity at the current moment, the pitch roll guidance attitude angular velocity of the satellite relative to the inertial frame at the current moment is determined. Based on the final guidance attitude, the attitude guidance angular rate, and the attitude guidance angular acceleration during the current pitch and roll guidance process, the pitch and roll guidance attitude angular acceleration of the satellite relative to the orbital system is determined. Combined with the current pitch and roll guidance attitude angular velocity of the satellite relative to the orbital system, the guidance attitude matrix of the satellite from the orbital system to the home system, and the orbital angular velocity of the satellite, the pitch and roll guidance attitude angular acceleration of the satellite relative to the inertial frame is determined.

4. A geosynchronous orbit synthetic aperture radar satellite on-board guidance attitude calculation device, used to implement the steps of the method described in any one of claims 1-3, characterized in that, include: The yaw guidance attitude calculation unit is used to calculate the guidance attitude of the satellite in yaw and pitch guidance mode at the current moment using the orbital parameters of the satellite at the current moment; The pitch guidance attitude calculation unit is used to calculate the guidance attitude of the satellite in pitch roll guidance mode by using the guidance attitude of the payload beam pointing in the current yaw pitch guidance mode. Under the satellite payload beam installation offset constraint, it calculates the final guidance attitude in the current pitch roll guidance process to correct the payload installation deviation. The guidance attitude command calculation unit is used to determine the attitude guidance angular rate and attitude guidance angular acceleration rate by using differential calculation method based on the final guidance attitude during the pitch and roll guidance process at the current moment and the previous moment, and to calculate the satellite pitch and roll guidance attitude quaternion at the current moment in combination with the orbital parameters, so that the Doppler frequency of the center point of the satellite's ground imaging target is zero.

5. A computer device, characterized in that, The computer device includes a memory and a processor. The memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory to implement the steps of the method according to any one of claims 1-3.

6. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steps of the method described in any one of claims 1-3.

7. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, implements the steps of the method according to any one of claims 1-3.

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