A method for attitude maneuvering of space target in motion push-broom imaging

Abstract

This invention proposes a method for attitude maneuvering in dynamic pushbroom imaging of space targets, which is highly practical for pushbroom imaging missions of moving space targets using spacecraft. Addressing the lack of attitude compensation maneuvering methods for pushbroom imaging of moving space targets, this invention proposes a method that performs initial screening of imaging timing based on imaging conditions, followed by pushbroom imaging along a given direction using a constant attitude angular velocity. This achieves active attitude pushbroom imaging of rapidly moving cooperative targets in space. This method can meet different imaging requirements by changing the threshold of the imaging screening conditions, and can obtain better space target imaging quality by adjusting the velocity coefficient to change the pushbroom speed and integration time.

Description

Technical Field

[0001] This invention belongs to the field of pushbroom imaging technology and relates to a method for attitude maneuvering in pushbroom imaging of space targets in motion. Background Technology

[0002] Space targets move at high speeds, and their relative motion with remote sensing satellites is complex. The spatial distance, relative angular velocity, relative direction of motion, and illumination conditions of the space target are all important factors affecting space target observation. Currently, there are three main methods for observing space targets using spacecraft: using area array cameras in a fixed attitude to capture the space target; using area array cameras in a staring tracking attitude to track and image the space target; and using line array cameras in a fixed attitude to capture the space target. Compared to area array imaging, line array pushbroom imaging is more challenging. Because pushbroom imaging only provides an instantaneous field of view in the pushbroom direction, the pushbroom timing needs to be very precise. Simultaneously, the pushbroom direction must be parallel to the relative motion direction of the space target on the spacecraft's image plane; otherwise, it will cause image blurring. The integration time of pushbroom imaging must also be strictly matched. Considering these factors, the number of space targets that can meet the imaging requirements is greatly reduced. If an active pushbroom method can be used for attitude maneuver compensation to achieve active pushbroom imaging along a space trajectory, the efficiency of pushbroom imaging detection of space targets will be greatly increased.

[0003] With the gradual maturation of imaging technology during satellite attitude maneuvers, satellites can achieve high attitude stability during these maneuvers, meeting the imaging flutter suppression requirements of space cameras. The monitoring of space targets has also gained increasing international attention due to the rapid increase in space debris. Huang Min proposed methods for imaging along oblique strips during attitude maneuvers in his national invention patents, "A Method for Oblique Strip Imaging of Targets During Agile Satellite Maneuvers" and "A Method for Attitude Maneuver Adjustment for Imaging Along Oblique Strips." These methods are for imaging ground targets, but have not yet addressed in-motion pushbroom imaging of space targets or trajectories. The observation of space targets involves numerous constraints. How to achieve high-quality imaging of space targets while meeting engineering practical constraints, such as spacecraft attitude angular velocity constraints, target observability constraints, and the actual capabilities of spacecraft optical cameras, remains a problem that needs further research. Summary of the Invention

[0004] The technical problem solved by this invention is: addressing the lack of attitude compensation maneuvering methods for push-broom imaging of moving targets in space, this invention proposes an attitude maneuvering method for push-broom imaging of moving targets in space. The method involves initial screening of imaging time based on imaging conditions, followed by push-broom imaging along a given direction using a constant attitude angular velocity, thereby achieving active attitude push-broom imaging of rapidly moving cooperative targets in space.

[0005] The solution of this invention is: a method for attitude maneuvering of space target in-motion push-broom imaging, comprising the following steps:

[0006] Calculate the scalar distance L between the spacecraft and the space target. rel angular velocity ω of relative motion rel Illumination conditions α for cooperative space targets tgt_so ;

[0007] According to L rel ω rel α tgt_so Determine the imaging constraints and select the observable time periods [t1,t2] for the space target;

[0008] Based on the imaging resolution requirements, determine the imaging distance L0, and determine L0 = L within the time interval [t1, t2]. rel The time is the pushbroom imaging time t0;

[0009] At time t0, given the push-broom velocity and the direction of motion of the space target, which are perpendicular to r... rel The size of the angle between the projections on the plane determines the angle perpendicular to r. rel The sweep direction v of the projection in the plane 合_P Calculate the push-sweep velocity in the vertical r rel The size V of the projection on the plane 合_p According to v 合_P and V 合_p Determine the vertical r rel The combined velocity V of the push-broom projection on the plane 合_p ;r rel It is a unit vector representing the relative distance between a space target and the main satellite in the orbital system;

[0010] According to V 合_p Calculate the integration time of the output push-broom camera and set the integration time to a fixed value;

[0011] According to V 合_p Calculate the entrainment velocity V caused by satellite attitude maneuvering 姿态 And the satellite's three-axis attitude at the push-broom imaging time;

[0012] Based on the satellite's three-axis attitude and entanglement velocity V 姿态 Calculate the component of attitude angular velocity in this system, and perform push-broom imaging of moving targets in space with uniform angular velocity.

[0013] Furthermore, the relative distance scalar L between the spacecraft and the space target rel angular velocity ω of relative motion rel The calculation method is as follows:

[0014] The relative distance R between a space target and a spacecraft in an orbital system rel and relative velocity V rel Represented as:

[0015] R rel =R tgt -R sat

[0016] V rel =V tgt -V sat

[0017] Among them, R sat R tgt V represents the positions of the main satellite and the space target in the J2000 inertial frame at time t, respectively. sat V tgt These represent the velocities of the satellite and the space target in the J2000 inertial frame at time t, respectively.

[0018] The relative distance scalar between the spacecraft and the space target is expressed as:

[0019] L rel =|R rel |

[0020] The relative angular velocity ω between the spacecraft and the space target rel Represented as:

[0021]

[0022] Furthermore, the illumination conditions α of the cooperative space target tgt_so The calculation method is as follows:

[0023]

[0024] α tgt_so =acos(r rel ·S o_tgt )

[0025] Where, r rel The relative distance R rel The unit vector, S o_tgt This represents the unit vector from the space target to the Sun. Further, based on constraints, the observable time periods [t1, t2] of the space target are selected, including:

[0026] L min ≤L rel ≤L max

[0027] α min ≤α tgt_so ≤α max

[0028] ω rel ≤ω max

[0029] Among them, L min L is the minimum allowable focusing distance for focusing an imaging optical system. max α is the maximum allowable focusing distance for the imaging optical system. min α is the minimum reflectivity of the space target determined by the imaging optics system. max ω is the maximum reflectivity of the space target determined by the imaging optical system. max This represents the maximum permissible attitude angular velocity during satellite imaging.

[0030] Furthermore, the imaging distance L0 is calculated as follows:

[0031]

[0032] Where ImR is the image resolution required for imaging, f is the focal length of the optical system, and d is the detector pixel size.

[0033] Furthermore, the determination of vertical r rel The sweep direction v of the projection in the plane 合_P ,include:

[0034] At time t0, the absolute velocity V of the spatial target tgt In vertical r rel The projection unit vector in the plane is:

[0035] V tgt_p =V tgt -(V tgt ·r rel )·r rel

[0036] The push-sweep speed is in the vertical r rel The sweep direction v of the projection in the plane 合_P According to V tgt_p The included angle η is calculated using the following formula:

[0037]

[0038] Furthermore, the push-broom speed is in the vertical r rel The size V of the projection on the plane 合_p The calculation method is as follows:

[0039]

[0040] Where, ω s R is the nominal angular velocity of the satellite. sWhere is the Earth's radius, H is the satellite's nominal orbital altitude, and k is the velocity coefficient, which determines the push-broom speed.

[0041] According to v 合_P and V 合_p Determine the vertical r rel The combined velocity V of the push-broom projection on the plane 合_p as follows:

[0042] V 合_p =V 合_p ·v 合_P .

[0043] Furthermore, the integration time of the pushbroom camera is calculated as follows:

[0044]

[0045] Furthermore, the entrainment velocity V caused by the satellite attitude maneuver 姿态 The calculation method is as follows:

[0046] V 姿态 =V tgt_p -V S_p -V 合_p

[0047] Among them, V S_p For the satellite's orbital velocity at r rel Projection in plane:

[0048] V S_p =V S -(V S ·r rel )·r rel

[0049] V S The entrainment velocity caused by the satellite's orbital motion;

[0050] The method for calculating the satellite's three-axis attitude at the pushbroom imaging time is as follows:

[0051] spacecraft Z b The axis points towards the space target.

[0052]

[0053] Where R0 is the relative distance R at time t0. rel ;

[0054] The Y-axis of the satellite b The axis is:

[0055]

[0056] Satellite X bThe axis is:

[0057] X b =Y b ×Z b .

[0058] Furthermore, the calculated components of the attitude angular velocity in this system include the rolling axis angular velocity ω in the body coordinate system. x and pitch axis angular velocity ω y The calculation method is as follows:

[0059]

[0060]

[0061] The advantages of this invention compared to the prior art are:

[0062] (1) The attitude adjustment method of this invention enables active push-broom imaging of space targets along a given direction. By actively pushing the spacecraft, push-brooming of the space target in any direction is achieved. When the push-broom direction is along the flight trajectory of the space target, the probability of target acquisition is greatly increased. Simultaneously, this invention constrains the push-broom attitude at the push-broom moment, eliminating the push-broom drift angle and satisfying the imaging requirement that the push-broom direction be perpendicular to the linear array direction during push-broom imaging. Considering the complex constraints of space target monitoring, this invention employs active push-brooming with the spacecraft's attitude to increase the probability of space targets being observable.

[0063] (2) The method of the present invention can achieve push-broom at different speeds by adjusting the velocity coefficient, and provides a method for calculating the integration time. It can adapt to push-broom imaging of the detector under different lighting conditions and ensure the imaging quality of space targets.

[0064] (3) The initial screening process for when a space target can be imaged in the method of this invention includes the main constraints on the observation of space targets, including the imaging distance considering the detection capability of the optical camera, the illumination conditions of the space target, and the relative attitude angular velocity considering the satellite's attitude maneuverability. The initial screening process is a prerequisite for mission simulation. Attached Figure Description

[0065] Figure 1 This is a flowchart of the method of the present invention;

[0066] Figure 2 A schematic diagram of the pushbroom imaging principle for space targets;

[0067] Figure 3 A schematic diagram of pushbroom imaging velocity synthesis for a space target.

[0068] Figure 4 Schematic diagrams for different push-broom directions;

[0069] Figure 5 A schematic diagram of the orbital parameters of a space target;

[0070] Figure 6 A schematic diagram of the spacecraft's orbital parameters;

[0071] Figure 7 A schematic diagram of the three-axis attitude pointing of a spacecraft for space imaging;

[0072] Figure 8 This is a schematic diagram of the pushbroom imaging process for a space target. Detailed Implementation

[0073] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0074] like Figure 1 As shown, the present invention proposes a method for attitude maneuvering of space target in motion push-broom imaging, which includes the following steps:

[0075] (1) Calculate the scalar distance L between the spacecraft and the space target. rel angular velocity ω of relative motion rel Illumination conditions α for cooperative space targets tgt_so ;

[0076] (2) According to L rel ω rel α tgt_so Determine the imaging constraints and select the observable time periods [t1,t2] for the space target;

[0077] (3) Determine the imaging distance L0 based on the imaging resolution requirements, and determine L0 = L within the time interval [t1, t2]. rel The time is the pushbroom imaging time t0;

[0078] (4) At time t0, given the combined push-broom velocity and the direction of motion of the space target, the two velocities are perpendicular to each other. rel The size of the angle between the projections on the plane determines the angle perpendicular to r. rel The sweep direction v of the projection in the plane 合_P Calculate the push-sweep velocity in the vertical r rel The size V of the projection on the plane 合_p According to v 合_P and V 合_p Determine the vertical r rel The combined velocity V of the push-broom projection on the plane 合_p ;r rel It is a unit vector representing the relative distance between a space target and the main satellite in the orbital system;

[0079] (5) According to V 合_pCalculate and output the integration time of the pushbroom camera, and set the integration time to a fixed value;

[0080] (6) Based on the push-sweep speed V 合_p Calculate the entrainment velocity V caused by satellite attitude maneuvering 姿态 And the satellite's three-axis attitude at the push-broom imaging time;

[0081] (7) Based on the satellite's three-axis attitude and the entrainment velocity V 姿态 Calculate the component of attitude angular velocity in this system, and perform push-broom imaging of moving targets in space with uniform angular velocity.

[0082] In step (1), the relative distance scalar L between the spacecraft and the space target is calculated. rel The details are as follows:

[0083] The relative distance R between the space target and the main satellite in the orbital system rel and relative velocity V rel It can be represented as:

[0084] R rel =R tgt -R sat (1)

[0085] V rel =V tgt -V sat (2)

[0086] Among them, R sat R tgt V represents the positions of the main satellite and the space target in the J2000 inertial frame at time t, respectively; sat V tgt The values ​​are the velocities of the satellite and the space target in the J2000 inertial frame at time t, respectively.

[0087] The relative distance scalar between a space target and its host satellite (spacecraft) can be expressed as:

[0088] L rel =|R rel | (3)

[0089] In step (1), the relative angular velocity ω between the spacecraft and the space target is calculated. rel The details are as follows:

[0090] The relative angular velocity between the space target and the satellite can be expressed as:

[0091]

[0092] In step (1), the illumination conditions α of the cooperative space target are calculated. tgt_soThe details are as follows:

[0093] The angle of sunlight incidence α of a space target (debris) tgt_so The calculation is as follows:

[0094]

[0095] α tgt_so =acos(r rel ·S o_tgt (6)

[0096] Where, r rel The relative distance R rel The unit vector, S o_tgt This is the unit vector from the space target to the Sun.

[0097] In step (2), the observable time periods [t1, t2] of the space target are selected according to the constraints, as follows:

[0098] Select the imaging time interval [t1, t2] that satisfies the following conditions:

[0099] L min ≤L rel ≤L max (7)

[0100] α min ≤α tgt_so ≤α max (8)

[0101] ω rel ≤ω max (9)

[0102] Among them, L min L is the minimum allowable focusing distance for focusing an imaging optical system. max L is the maximum allowable focusing distance for the imaging optical system. min and L max Determined based on the focusing capability of the imaging optical system; α min α is the minimum reflectivity of the space target determined by the imaging optics system. max α is the maximum reflectivity of the space target determined by the imaging optical system. min and α max The angle is determined based on the dynamic range of the imaging optical system and the reflectivity of the target in space, and is generally selected from 20° to 70°; ω max This represents the maximum permissible attitude angular velocity during satellite imaging.

[0103] In step (3), the imaging distance L0 and the push-broom imaging time t0 are determined as follows:

[0104] Calculate the required imaging time distance L0 based on the image resolution ImR required for imaging:

[0105]

[0106] Where f is the focal length of the optical system and d is the pixel size of the detector.

[0107] Within the time interval [t1, t2], find the corresponding time t0 such that L0 = L rel The corresponding time t0 is the push-broom imaging time.

[0108] In step (4), the direction of the push sweep is determined as follows:

[0109] At the space target location, the entrainment velocity V caused by the satellite's orbital motion S The entrainment velocity V caused by satellite attitude maneuvering 姿态 (Unknown), the absolute velocity V of the target orbit tgt The relative velocity V of the space target relative to the phase surface is synthesized. 合 That is, the push-sweep speed V 合 The above four speeds satisfy the following relationship, see Figure 2 and Figure 3 .

[0110] V 合 =V tgt -V S -V 姿态 (11)

[0111] At time t0, the absolute velocity V of the target orbit tgt In vertical r rel The projection unit vector in the plane is:

[0112] V tgt_p =V tgt -(V tgt ·r rel )·r rel (12)

[0113] Push-sweep speed V 合 In vertical r rel The unit vector v of the projection in the plane 合_P According to V tgt_p The included angle is calculated using the following formula:

[0114]

[0115] v 合_P This refers to the defined push-broom direction. The push-broom velocity is perpendicular to the direction of the target's motion in space. relThe included angle η of the projection on the plane is given by the user. When η = 0, it represents a sweep along the direction of the spatial target trajectory; when η = 180°, it represents a sweep in the opposite direction of the spatial target trajectory. (See...) Figure 4 .

[0116] In step (4), the push-sweep velocity is calculated in the vertical direction r. rel Size V in the plane 合_p The details are as follows:

[0117]

[0118] Where, ω s R is the nominal angular velocity of the satellite. s Where is the Earth's radius, H is the satellite's nominal orbital altitude, and k is the velocity coefficient, determining the pushbroom speed based on the satellite's attitude maneuverability. When k = 1, V 合_p This is equivalent to using the satellite's nadir point ground velocity for push sweeping.

[0119] Furthermore, according to v 合_P and V 合_p Determine the vertical r rel The combined velocity V of the push-broom projection on the plane 合_p :

[0120] V 合_p =V 合_p ·v 合_P (15)

[0121] In step (5), the integration time of the pushbroom camera is calculated as follows:

[0122] Integration time T of the push-broom camera int Set to a fixed value:

[0123]

[0124] The integration time, as an output, is used to set the integration time of the pushbroom camera at the time t0 when it images the space target, thereby matching the pushbroom speed of the space target.

[0125] In step (6), according to formula (11), and due to the entrainment velocity caused by the satellite attitude motion in the vertical r rel In the plane, at the perpendicular to r rel Calculate V in the plane 姿态 :

[0126] V 姿态 =V tgt_p -V S_p -V 合_p (17)

[0127] Where V S_pFor the satellite's orbital velocity at r rel Projection in plane:

[0128] V S_p =V S -(V S ·r rel )·r rel (18)

[0129] In step (6), the satellite's three-axis attitude is calculated at the push-broom imaging time, as follows:

[0130] The spacecraft's attitude at the time of push-broom imaging is:

[0131] spacecraft Z b The line of sight (or axis of view) points towards the target in space.

[0132]

[0133] Where R0 is R at time t0 rel .

[0134] The Y-axis of the satellite b The axis is:

[0135]

[0136] Satellite X b The axis is:

[0137] X b =Y b ×Z b (twenty one)

[0138] In step (7), the components of the attitude angular velocity in this system are calculated, including the roll axis angular velocity and pitch axis angular velocity in the body coordinate system.

[0139] The tracking attitude angular velocity in the spacecraft body coordinate system is calculated using formulas (22) and (23), which are the roll axis angular velocity and pitch axis angular velocity, respectively.

[0140]

[0141]

[0142] During the short-term push-broom imaging of a moving target in space, a uniform angular velocity is used for push-brooming.

[0143] Example 1

[0144] For the selection of orbital parameters for space targets, see [link to relevant documentation]. Figure 5 Spacecraft orbital parameters are shown below. Figure 6 .

[0145] Select 500≤Lrel ≤700km, imaging visibility condition 0≤α tgt_so ≤70°, ω rel With an angular velocity ≤2° / s, there are 8 time slots available, as shown in Table 1. Considering camera imaging resolution and other requirements, the optimal imaging distance is around 594km. The imaging time was chosen as 9:42:05 Beijing time on February 27, 2023, and the velocity coefficient k was set to 1. Calculations yielded the following attitude Euler angles (123 rotation sequence): 60.356°, -42.46°, 121.183°; the attitude angular velocity was 0.68° / s, the relative push-broom velocity was 6.686km / s, and the corresponding integration time was 44.6µs. Figure 7 This is a schematic diagram of the spacecraft's attitude during imaging. Figure 8 This is a schematic diagram of STK push-broom imaging simulation.

[0146] Table 1

[0147]

[0148] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0149] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for attitude maneuvering of space target in motion push-broom imaging, characterized in that, Includes the following steps: Calculate the scalar distance L between the spacecraft and the space target. rel angular velocity ω of relative motion rel Illumination conditions α for cooperative space targets tgt_so ; According to L rel ω rel α tgt_so Determine the imaging constraints and select the observable time periods [t1,t2] for the space target; Based on the imaging resolution requirements, determine the imaging distance L0, and determine L0 = L within the time interval [t1, t2]. rel The time is the pushbroom imaging time t0; At time t0, given the push-broom velocity and the direction of motion of the space target, which are perpendicular to r... rel The size of the angle between the projections on the plane determines the angle perpendicular to r. rel The sweep direction v of the projection in the plane 合_P Calculate the push-sweep velocity in the vertical r rel The size V of the projection on the plane 合_p According to v 合_P and V 合_p Determine the vertical r rel The combined velocity V of the push-broom projection on the plane 合_p ;r rel It is a unit vector representing the relative distance between a space target and the main satellite in the orbital system; According to V 合_p Calculate the integration time of the output push-broom camera and set the integration time to a fixed value; According to V 合_p Calculate the entrainment velocity V caused by satellite attitude maneuvering 姿态 And the satellite's three-axis attitude at the push-broom imaging time; Based on the satellite's three-axis attitude and entanglement velocity V 姿态 Calculate the component of attitude angular velocity in this system, and perform push-broom imaging of moving targets in space with uniform angular velocity.

2. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 1, characterized in that, The relative distance scalar L between the spacecraft and the space target rel angular velocity ω of relative motion rel The calculation method is as follows: The relative distance R between a space target and a spacecraft in an orbital system rel and relative velocity V rel Represented as: R rel =R tgt -R sat V rel =V tgt -V sat Among them, R sat R tgt V represents the positions of the main satellite and the space target in the J2000 inertial frame at time t, respectively. sat V tgt These represent the velocities of the satellite and the space target in the J2000 inertial frame at time t, respectively. The relative distance scalar between the spacecraft and the space target is expressed as: L rel =|R rel | The relative angular velocity ω between the spacecraft and the space target rel Represented as:

3. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 2, characterized in that, The illumination conditions α of the cooperative space target tgt_so The calculation method is as follows: a tgt_so =acos(r rel ·S o_tgt ) Where, r rel The relative distance R rel The unit vector, S o_tgt This is the unit vector from the space target to the Sun.

4. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 3, characterized in that, Based on the constraints, the observable time periods [t1, t2] of space targets are selected, including: L min ≤L rel ≤L max α min ≤α tgt_so ≤α max oh rel ≤ω max Among them, L min L is the minimum allowable focusing distance for focusing an imaging optical system. max α is the maximum allowable focusing distance for the imaging optical system. min α is the minimum reflectivity of the space target determined by the imaging optics system. max ω is the maximum reflectivity of the space target determined by the imaging optical system. max This represents the maximum permissible attitude angular velocity during satellite imaging.

5. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 1, characterized in that, The imaging distance L0 is calculated as follows: Where ImR is the image resolution required for imaging, f is the focal length of the optical system, and d is the detector pixel size.

6. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 3, characterized in that, The determination is made at the vertical r rel The sweep direction v of the projection in the plane 合_P ,include: At time t0, the absolute velocity V of the spatial target tgt In vertical r rel The projection unit vector in the plane is: V tgt_p =V tgt -(V tgt ·r rel )·r rel The push-sweep speed is in the vertical r rel The sweep direction v of the projection in the plane 合_P According to V tgt_p The included angle η is calculated using the following formula:

7. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 5, characterized in that, The push-broom speed is in the vertical r rel The size V of the projection on the plane 合_p The calculation method is as follows: Where, ω s R is the nominal angular velocity of the satellite. s Where is the Earth's radius, H is the satellite's nominal orbital altitude, and k is the velocity coefficient, which determines the push-broom speed. According to v 合_P and V 合_p Determine the vertical r rel The combined velocity V of the push-broom projection on the plane 合_p as follows: V 合_p =V 合_p ·v 合_P 。 8. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 7, characterized in that, The integration time of the pushbroom camera is calculated as follows:

9. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 6, characterized in that, The drag velocity V caused by the satellite attitude maneuver 姿态 The calculation method is as follows: V 姿态 =V tgt_p -V S_p -V 合_p Among them, V S_p For the satellite's orbital velocity at r rel Projection in plane: V S_p =V S -(V S ·r rel )·r rel V S The entrainment velocity caused by the satellite's orbital motion; The method for calculating the satellite's three-axis attitude at the pushbroom imaging time is as follows: spacecraft Z b The axis points towards the space target. Where R0 is the relative distance R at time t0. rel ; The Y-axis of the satellite b The axis is: Satellite X b The axis is: X b =Y b ×Z b 。 10. The method for attitude maneuvering of a space target in motion push-broom imaging according to claim 9, characterized in that, The calculated components of the attitude angular velocity in this system include the rolling axis angular velocity ω in the body coordinate system. x and pitch axis angular velocity ω y The calculation method is as follows:

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