A high-dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method and device

Abstract

This invention proposes a high-dynamic real-time yaw rate adjustment and image shift compensation optical scanning imaging method and device, belonging to the field of optical remote sensing technology. It solves the technical problem of ensuring the quality of satellite on-orbit imaging. The method includes: using a combined imaging mode of vertical orbit scanning with a tilting mirror and pitch return to perform high-dynamic vertical orbit wide-area scanning imaging, determining the satellite imaging motion law, and establishing a high-precision multi-coordinate system object-image geometric mapping and image shift calculation model to calculate the variation law of image shift compensation parameters; measuring satellite orbit information, attitude information, and camera optical axis pointing information through a high-precision sensor, predicting the camera optical axis motion law using filtering, and substituting it into the image shift calculation model to obtain the line frequency; and achieving graded yaw rate adjustment through fixed yaw rate adjustment, curve fitting, and adjustment of the installation angle. This invention is applied to optical remote sensing satellites with high-dynamic vertical orbit wide-area scanning imaging, achieving on-orbit image shift compensation imaging that balances wide-area coverage and high resolution.

Description

Technical Field

[0001] This invention belongs to the field of optical remote sensing technology and is specifically applied to optical remote sensing satellites with high dynamic vertical orbit wide-area scanning imaging, realizing on-orbit image shift compensation imaging that balances wide-area coverage and high resolution. Background Technology

[0002] Current mainstream optical remote sensing satellites typically employ static pushbroom imaging, meaning the satellite maintains three-axis stability with the camera fixed to the satellite platform. However, limitations imposed by payload weight and camera optical design restrict the expansion of the payload's field of view, resulting in a trade-off between swath width and resolution. To overcome this issue, some satellites use multi-camera stitching, but this remains constrained by payload weight, hindering further swath width expansion. Some small satellites utilize their maneuverability for side-swing imaging to extend the coverage area of ​​a single track, but this does not address the issue of simultaneous coverage of wide-area ground features. Therefore, to meet the requirements of high-resolution wide-area ground feature coverage, it is necessary to move the optical payload relative to the satellite platform, causing the payload's optical axis to move at high speed in the vertical direction, thereby expanding the imaging area per unit time, as illustrated in patent CN107152926B. In this case, the image motion velocity vector of ground features at the payload's focal plane exhibits large-scale nonlinear anisotropic variations, making it difficult for conventional satellites with fixed image motion compensation parameters (line frequency, drift angle, etc.) to meet imaging requirements. Summary of the Invention

[0003] In view of this, the present invention aims to propose a high dynamic real-time bias-adjustment rheometry line frequency image shift compensation optical scanning imaging method and device to solve the technical problem of ensuring satellite on-orbit imaging quality.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: This invention proposes a high-dynamic real-time bias-adjustment rheometry line frequency image shift compensation optical scanning imaging method, characterized in that the method includes: S1. High-dynamic vertical rail wide-area scanning imaging is performed using a combination of vertical rail oscillation and pitch return imaging modes to determine the satellite imaging motion law. Based on the satellite imaging motion law, a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model is established to calculate the variation law of image motion compensation parameters. The variation law of image motion compensation parameters includes the variation law of detector line frequency and the variation law of yaw angle. S2. Measure satellite orbit information, attitude information, and camera optical axis pointing information using a high-precision sensor, predict the camera optical axis motion law using filtering, and substitute it into the image shift calculation model to obtain the line frequency; S3. Based on the deflection angle variation law of S1 and the camera optical axis motion law of S2, the deflection angle is adjusted in stages by fixing the deflection angle, curve fitting and adjusting the installation angle.

[0005] Furthermore, the process of high dynamic vertical rail wide-area scanning imaging using a combination of tilting mirror vertical rail scanning and pitch return imaging as described in S1 includes: S11. Set the satellite's nadir projection velocity to v, and the satellite's orbital altitude to H. The required pitch yaw rate is: ; S12. If the swath width of each strip's nadir point excluding the area overlapping with the next strip along the orbital direction is W, and the effective imaging time within the imaging cycle is T, then the acceleration / deceleration reset time is... Then the imaging period of each strip satisfies: ; S13, the period of the sine curve is If the amplitude is A, then the angular velocity curve is: ; S14. The requirement is that the swing completes its reset within one imaging cycle, i.e., the area enclosed by the angular velocity-time curve is 0. This yields: ; S15. If the required angular motion range of the optical axis is Φ within the effective imaging time T, then the angular velocity of the oscillating mirror is: ; S16. The angular velocity during pitch acceleration and deceleration must track a sine curve, with a period of [missing information]. The amplitude is The law governing angular velocity is as follows: .

[0006] Furthermore, the satellite imaging motion law described in S1 establishes a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model by sequentially passing through a seven-coordinate system transformation: the nadir point horizon coordinate system G, the geocentric fixed coordinate system E, the geocentric inertial coordinate system I, the satellite orbit coordinate system O, the satellite body coordinate system B, the camera coordinate system C, and the image space coordinate system P. The homogeneous transformation matrix from coordinate system A to coordinate system B is defined as MBA.

[0007] Furthermore, the S2 process includes: S21. Use a high-precision GNSS receiver to measure satellite orbit information and perform satellite orbit determination; S22. Use high-precision star sensors and fiber optic gyroscopes to measure the satellite's attitude angle deviation and angular velocity deviation to determine the satellite's attitude information; S23. Use a high-precision encoder and fiber optic gyroscope to measure the rotation angle and angular velocity of the pendulum mirror in two directions to determine the camera optical axis pointing information; S24. Introduce Kalman filtering to predict the motion law of the camera optical axis and determine the pointing information of the camera optical axis; S25. Substitute the motion law of the camera optical axis into the image shift calculation model described in S1 to calculate the line frequency.

[0008] Furthermore, the TDI detector drive signal is updated in real time using the line frequency to adjust the imaging line frequency.

[0009] Furthermore, the fixed deflection angle adjustment described in S3 includes selecting a fixed deflection angle adjustment amount and excluding a fixed deflection angle adjustment amount.

[0010] Furthermore, the selected fixed deflection angle adjustment amount is: , in, , where is the instantaneous value of the deflection angle of the i-th detector at imaging time t; n is the total number of detectors, and t is the effective imaging time.

[0011] Furthermore, the amount of adjustment to exclude the fixed deflection angle is: , Using the least squares method The dynamic deflection angle fitting curve is obtained by fitting. .

[0012] Furthermore, the installation angle is: .

[0013] This invention also proposes a high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging device, the device comprising: The imaging mode selection and compensation parameter calculation module is used to perform high-dynamic vertical rail wide-area scanning imaging using a combination of vertical rail scanning and pitch return imaging modes, determine the satellite imaging motion law, and establish a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model based on the satellite imaging motion law, and calculate the variation law of image motion compensation parameters; the variation law of image motion compensation parameters includes the variation law of detector line frequency and the variation law of yaw angle; The on-orbit adaptive line frequency module is used to measure satellite orbit information, attitude information, and camera optical axis pointing information through high-precision sensors, predict the camera optical axis motion law by filtering, and substitute it into the image motion calculation model to obtain the line frequency. A graded deflection angle adjustment module; used to achieve graded deflection angle adjustment based on the deflection angle variation law and the camera optical axis motion law, through fixed deflection angle adjustment, curve fitting and installation angle adjustment.

[0014] Compared with the prior art, the beneficial effects of the present invention are: The high dynamic real-time offset rheodynamic line frequency image shift compensation optical scanning imaging method described in this invention can ensure the on-orbit imaging quality of satellites and has high engineering significance.

[0015] The combined imaging mode of vertical rail scanning and pitch return described in this invention effectively achieves high-dynamic vertical rail wide-area scanning imaging. By synchronously executing uniform vertical rail scanning and uniform pitch return within the effective imaging time, it achieves staring imaging along the rail direction towards the ground. During the acceleration and deceleration of the vertical rail scanning, the pitch return is synchronously completed, smoothly realizing the reverse direction uniform vertical rail scanning and along-rail staring imaging of the next strip. This mode eliminates the projected velocity of the satellite orbital motion at the nadir point as much as possible through pitch return, effectively preventing abrupt changes in the yaw angle during the scanning of two adjacent strips, and avoiding the adverse effects of abrupt changes on control accuracy. Based on the satellite imaging motion law determined by this mode, a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model can accurately calculate the changes in image motion compensation parameters, including the changes in detector line frequency and yaw angle, providing a reliable basis for subsequent image motion compensation and ensuring the realization of wide-area coverage and high-resolution imaging requirements. During on-orbit operation, the payload accurately measures satellite orbit, attitude angle deviation, angular velocity deviation, and rotation angle and angular velocity in both directions of the tilting mirror using high-precision sensors such as a high-precision GNSS receiver, star sensor, fiber optic gyroscope, and encoder. This provides accurate basic data for line frequency calculation. By introducing Kalman filtering to predict the camera optical axis motion law, the delay in position and attitude measurement and calculation is effectively compensated, enabling the extrapolation of the camera optical axis motion law. Substituting the predicted camera optical axis motion law into the image shift calculation model, the line frequency can be accurately obtained. Then, by updating the TDI detector drive signal in real time, the imaging line frequency is adjusted, ensuring the accuracy of on-orbit line frequency calculation and ensuring that the imaging line frequency is accurately matched with the actual image shift requirements. This provides reliable line frequency adjustment support for image shift compensation in high dynamic range imaging. Based on the analysis of the yaw angle variation pattern, the satellite yaw direction or the adjustment of the fixed installation angle of the camera is determined in advance. At the same time, the installation angle is adjusted in combination with the differences in the yaw angle of each detector, which effectively offsets part of the yaw angle influence in advance and reduces the pressure of yaw angle adjustment in orbit. When working in orbit, the yaw angle is obtained by substituting the filtered camera motion law into the image shift calculation model. The smoothness of the yaw angle trajectory is ensured by least square fitting. With the follow-up adjustment of the yaw angle adjustment mechanism of the camera focal plane, the precise and continuous control of the yaw angle is realized, avoiding the adverse effects of sudden yaw angle changes on control accuracy, ensuring the imaging consistency of each detector in the full field of view, and further guaranteeing the high dynamic range wide-field imaging quality.

[0016] This invention belongs to the field of optical remote sensing technology and is specifically applied to optical remote sensing satellites with high dynamic vertical orbit wide-area scanning imaging, realizing on-orbit image shift compensation imaging that balances wide-area coverage and high resolution. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a flowchart of a high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging device according to the present invention.

[0019] Figure 2 This is a schematic diagram of the combined imaging mode of vertical track oscillation and pitch return of the oscillating mirror in this invention.

[0020] Figure 3 This is the pitch motion process and angular velocity-time variation curve of the present invention.

[0021] Figure 4 This is the angular velocity-time variation curve during the sweeping motion process of this invention.

[0022] Figure 5 This is the line frequency variation curve of a certain strip of 13 detectors in this invention.

[0023] Figure 6 This is a curve showing the change in the deflection angle of a certain strip of 13 detectors in this invention.

[0024] Figure 7 This is the on-orbit adaptive line frequency matching process of the present invention.

[0025] Figure 8 The image shows the residual curves of the deflection angles of each detector after the deflection mechanism of this invention is dynamically adjusted according to the fitted curve.

[0026] Figure 9 This invention relates to an on-orbit lateral flow angle stratification adjustment strategy. Detailed Implementation

[0027] 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 only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Specific implementation method one, such as Figure 1 As shown in this embodiment, a high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method is described, the method comprising: S1. High-dynamic vertical rail wide-area scanning imaging is performed using a combination of vertical rail oscillation and pitch return imaging modes to determine the satellite imaging motion law. Based on the satellite imaging motion law, a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model is established to calculate the variation law of image motion compensation parameters. The variation law of image motion compensation parameters includes the variation law of detector line frequency and the variation law of yaw angle. Specifically, this includes the selection of optical scanning imaging mode and the calculation of image shift compensation parameters; To achieve high-dynamic vertical-orbit wide-area scanning imaging, a combined imaging mode of tilting mirror vertical-orbit scanning and pitch return is adopted. This mode is used for high-dynamic vertical-orbit wide-area scanning imaging to determine the satellite imaging motion law. Based on this satellite imaging motion law, a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model is established to calculate the variation law of image motion compensation parameters. The variation law of image motion compensation parameters includes the variation law of detector line frequency and the variation law of yaw angle. The imaging process is as follows: Within the effective imaging time, uniform pitch oscillation is performed simultaneously with uniform-speed vertical rail scanning to achieve staring imaging along the rail direction. During the acceleration and deceleration of the vertical rail scanning, the pitch oscillation is simultaneously reset, enabling the next strip to undergo uniform-speed vertical rail scanning and staring imaging in the opposite direction. The imaging process is as follows: Figure 2 As shown.

[0029] The core purpose of this mode's pitch oscillation process is to minimize the projected velocity of the satellite's orbital motion at the nadir point. This is to prevent abrupt changes in the yaw angle during the scanning of two adjacent strips, which could adversely affect control accuracy. (Satellite nadir point projected velocity) v Represented as

[0030] in, μ The gravitational constant is the constant of gravity. R For the Earth's radius, H For the satellite orbital altitude, the required pitch gyration angular velocity is:

[0031] If the width of the region excluding the overlapping area with the next strip along the orbital direction of each strip's sub-satellite point is... W This requires that the imaging period (including the effective imaging time) for each strip be... T and acceleration / deceleration reset time t 0) Satisfies

[0032] The pitch motion process and the angular velocity-time change curve are as follows: Figure 3 As shown. For ease of control, the angular velocity during pitch acceleration and deceleration tracks a sine curve, with a period of 1 / 2... t 0, amplitude is A The angular velocity curve is then...

[0033] like Figure 4 As shown, the swing is required to complete its reset within one imaging cycle, meaning the area enclosed by the angular velocity-time curve is 0.

[0034] It can be solved

[0035] During the acceleration and deceleration of the tilting mirror in the pitch direction, the tilting mirror in the vertical direction must simultaneously complete the process of changing its angular velocity to the same magnitude and reverse direction as in the previous imaging cycle, as shown in the motion curve. Figure 5 As shown. During the effective imaging time T If the required angular range of motion of the optical axis is Φ, then the angular velocity of the pendulum mirror is:

[0036] Similarly, it is required that the angular velocity during pitch acceleration and deceleration track a sine curve, with a period of 2... t 0, amplitude is ω ⊥ The law governing angular velocity is as follows:

[0037] Thus, the satellite's motion during imaging can be determined. To obtain image shift compensation parameters during payload imaging, a high-precision multi-coordinate system object-image geometric mapping and image shift calculation model needs to be constructed. This embodiment abstracts the object-image geometric mapping model into a seven-coordinate system transformation process: nadir point horizon coordinate system (G) - geocentric fixed coordinate system (E) - geocentric inertial coordinate system (I) - satellite orbit coordinate system (O) - satellite body coordinate system (B) - camera coordinate system (C) - image space coordinate system (P). (The homogeneous transformation matrix from coordinate system A to coordinate system B is used...) M BA (Indicated). Among them: (1) The time-varying matrix for the conversion from the geocentric fixed coordinate system (E) to the geocentric inertial coordinate system (I), with the rotational angular velocity being the Earth's rotational angular velocity. ω e ; (2) The conversion from the geocentric inertial coordinate system (I) to the satellite orbital coordinate system (O) is a time-varying matrix, and the rotation angular velocity is the satellite orbital angular velocity. ωo ; (3) The conversion from the satellite orbit coordinate system (O) to the satellite body coordinate system (B) is a time-varying matrix, and the rate of change is determined by the deviation of the satellite's three-axis angular velocity; (4) The time-varying matrix for the conversion from the satellite body coordinate system (B) to the camera coordinate system (C). In this embodiment, the C system is defined relative to the B system as a time-varying matrix. x Axis rotation azimuth angle φ and around y Axis rotation pitch angle θ Achieving this through two rotations results in the transformation matrix being:

[0038] Among them, azimuth rate Characterizing the vertical sweeping motion, pitch angular velocity This represents the pitch and oscillation motion. At this time, the coordinates of the object point... Image point coordinates The transformation relationship can be expressed as

[0039] in M BA ( t The matrix ) indicates that it is a time-varying matrix. The instantaneous image velocity of the image point can be obtained by taking the derivative.

[0040] Corresponding TDI detector line frequency f and deflection angle β for

[0041] in, δ Let be the detector pixel size. The calculated line frequency and yaw angle curves for 13 detectors within a certain band are shown in Figures [Figure Number]. Figure 6 As shown, it can be observed that within the same band, the line frequency and yaw angle curves of different detectors exhibit a wide range of dynamic changes, and the variation patterns among different detectors are not entirely the same. Therefore, it is necessary to achieve on-orbit adaptive line frequency matching and yaw angle adjustment, and to balance the requirements of full-field-of-view detectors.

[0042] S2. Measure satellite orbit information, attitude information, and camera optical axis pointing information using a high-precision sensor, predict the camera optical axis motion law using filtering, and substitute it into the image shift calculation model to obtain the line frequency; Specifically, on-orbit adaptive line frequency matching: During the on-orbit operation of the payload, the satellite orbit, attitude and camera optical axis pointing information are measured by a high-precision sensor. The motion law of the camera optical axis is predicted by filtering and substituted into the image shift calculation model to obtain the line frequency, thereby updating the TDI detector drive signal in real time to adjust the imaging line frequency.

[0043] According to the image motion velocity calculation formula, in order to ensure the accuracy of on-orbit calculation, on the one hand, a high-precision sensor is needed to accurately measure the satellite's position and attitude as well as the camera's tilting mirror rotation angle. On the other hand, due to the delay in position and attitude measurement and calculation, it is necessary to extrapolate the optical axis pointing motion law.

[0044] Therefore, this embodiment employs a high-precision GNSS receiver for satellite orbit determination, a high-precision star sensor and fiber optic gyroscope to determine the satellite's attitude angle and angular velocity deviations, a high-precision encoder and fiber optic gyroscope to determine the rotation angles and angular velocities of the tilting mirror in two directions, and introduces Kalman filtering to predict the camera's optical axis motion. These are then substituted into the image shift calculation model to obtain the line frequency, thereby updating the TDI detector drive signal in real time to adjust the imaging line frequency. The on-orbit adaptive line frequency matching process is as follows: Figure 7 As shown.

[0045] S3. Based on the deflection angle variation law of S1 and the camera optical axis motion law of S2, the deflection angle is adjusted in stages by fixing the deflection angle, curve fitting and adjusting the installation angle.

[0046] Specifically, the deflection angle is adjusted in stages; Based on the analysis of the yaw angle variation pattern, the satellite yaw direction or the adjustment of the fixed installation angle of the camera is determined in advance. At the same time, the installation angle is adjusted in combination with the difference of the yaw angle of each detector. When working in orbit, the yaw angle is obtained by substituting the camera motion law obtained by filtering into the image motion calculation model. At the same time, least squares fitting is performed to ensure the smoothness of the trajectory. The yaw angle adjustment mechanism of the camera focal plane is used to achieve the adjustment of the yaw angle.

[0047] The variation process of the deflection angle shows that the variation law of the deflection angle of each detector in orbit approximately follows a parabolic shape, and the variation range is between 0 and 1°. Therefore, the following method is adopted for graded adjustment of the deflection angle: (1) To reduce the motion space envelope of the flow adjustment mechanism, the angular motion range of the flow adjustment mechanism needs to be limited to around 0°. Therefore, let's denote... n The variation law of the deflection angle of the plate detector is as follows Then select a fixed deflection angle adjustment amount. for

[0048] This adjustment is achieved by adjusting the fixed yaw angle of the satellite itself or by offset mounting the camera during installation.

[0049] (2) The deflection mechanism tracks the dynamic curve on track. To achieve deflection angle adjustment, this curve is set as the average value of the deflection angle changes of each detector, excluding fixed deflection angle adjustments.

[0050] Meanwhile, to avoid poor smoothness of the calculated deflection angle curve, which could adversely affect control, the least squares method is used. The curve was obtained by fitting. In this embodiment, a quadratic function is used to fit the parabola. The residual curves of the deflection angle of each detector after fitting are shown below. Figure 8 As shown, it can be seen that after the deflection mechanism is dynamically adjusted, the deflection angle compensation accuracy of each detector is greatly improved compared to adjusting the deflection angle only.

[0051] (3) To further improve the accuracy of the detector deflection angle adjustment, the installation angle of each detector on the focal plane can be adjusted. In this embodiment, the angle is taken as the average value of the residual deflection angle of each detector in the strip.

[0052] The final installation angles of each detector are shown in the table below.

[0053]

[0054] It should be noted that, for ease of explanation, the above embodiments only determine the deviation angle variation law based on the change of a single strip. In actual design, since the fixed camera mounting angle and detector mounting angle cannot be changed on track, the design method should be modified as follows: (1) Calculate the deflection angle variation curves of each detector in the multi-track and multi-strip multi-strip multi-operation mode based on the image shift compensation model, and fix the deflection angle adjustment amount. It should be determined statistically based on the variation curves of multiple tracks and strips; if each strip obtains If the difference is too large, the average value of each strip is selected as the camera installation angle (not changed in orbit), and the residual part is achieved by adjusting the satellite yaw angle, and the satellite yaw angle remains fixed during the imaging process of each strip; (2) Dynamic curve of the deflection adjustment mechanism for each belt Individual fitting can be performed, but the installation angle of each detector should be determined according to the statistical analysis of the deflection angle residuals of each detector in the multi-track, multi-strip system to ensure the accuracy of deflection angle compensation throughout the imaging process. After the detector installation angle is determined, the detector will be fixed on the focal plane assembly and cannot move. On-track, the deflection adjustment mechanism will drive the focal plane assembly to move according to the fitted trajectory.

[0055] In summary, to achieve high-precision compensation for the yaw angle, a layered adjustment strategy is adopted, consisting of dynamic adjustment of the satellite yaw angle, fixed adjustment of the camera's mounting angle relative to the satellite body, fixed adjustment of the detector's mounting angle relative to the focal plane assembly, and dynamic adjustment of the focal plane driven by the yaw adjustment mechanism. Figure 9 As shown.

[0056] Specific implementation method two: The high dynamic real-time bias-adjustment rheotropic line frequency image shift compensation optical scanning imaging device described in this embodiment includes: The imaging mode selection and compensation parameter calculation module is used to perform high-dynamic vertical rail wide-area scanning imaging using a combination of vertical rail scanning and pitch return imaging modes, determine the satellite imaging motion law, and establish a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model based on the satellite imaging motion law, and calculate the variation law of image motion compensation parameters; the variation law of image motion compensation parameters includes the variation law of detector line frequency and the variation law of yaw angle; The on-orbit adaptive line frequency module is used to measure satellite orbit information, attitude information, and camera optical axis pointing information through high-precision sensors, predict the camera optical axis motion law by filtering, and substitute it into the image motion calculation model to obtain the line frequency. A graded deflection angle adjustment module; used to achieve graded deflection angle adjustment based on the deflection angle variation law and the camera optical axis motion law, through fixed deflection angle adjustment, curve fitting and installation angle adjustment.

Claims

1. A high-dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method, characterized in that, The method includes: S1. High-dynamic vertical rail wide-area scanning imaging is performed using a combination of vertical rail oscillation and pitch return imaging modes to determine the satellite imaging motion law. Based on the satellite imaging motion law, a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model is established to calculate the variation law of image motion compensation parameters. The variation law of image motion compensation parameters includes the variation law of detector line frequency and the variation law of yaw angle. S2. Measure satellite orbit information, attitude information, and camera optical axis pointing information using a high-precision sensor, predict the camera optical axis motion law using filtering, and substitute it into the image shift calculation model to obtain the line frequency; S3. Based on the deflection angle variation law of S1 and the camera optical axis motion law of S2, the deflection angle is adjusted in stages by fixing the deflection angle, curve fitting and adjusting the installation angle.

2. The high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method according to claim 1, characterized in that, The process of high dynamic vertical rail wide-area scanning imaging using a combination of vertical rail oscillation and pitch return imaging modes, as described in S1, includes: S11. Set the satellite's nadir projection velocity to v, and the satellite's orbital altitude to H. The required pitch yaw rate is: ； S12. If the swath width of each strip's nadir point excluding the area overlapping with the next strip along the orbital direction is W, and the effective imaging time within the imaging cycle is T, then the acceleration / deceleration reset time is... Then the imaging period of each strip satisfies: ； S13, the period of the sine curve is If the amplitude is A, then the angular velocity curve is: ； S14. The requirement is that the swing completes its reset within one imaging cycle, i.e., the area enclosed by the angular velocity-time curve is 0. This yields: ； S15. If the required angular motion range of the optical axis is Φ within the effective imaging time T, then the angular velocity of the oscillating mirror is: ； S16. The angular velocity during pitch acceleration and deceleration must track a sine curve, with a period of [missing information]. The amplitude is The law governing angular velocity is as follows: 。 3. The high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method according to claim 1, characterized in that, The satellite imaging motion law described in S1 establishes a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model, which involves a seven-coordinate system transformation sequentially through the nadir point horizon coordinate system G, the geocentric fixed coordinate system E, the geocentric inertial coordinate system I, the satellite orbit coordinate system O, the satellite body coordinate system B, the camera coordinate system C, and the image space coordinate system P. The homogeneous transformation matrix from coordinate system A to coordinate system B is defined as MBA.

4. The high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method according to claim 1, characterized in that, The process of S2 includes: S21. Use a high-precision GNSS receiver to measure satellite orbit information and perform satellite orbit determination; S22. Use high-precision star sensors and fiber optic gyroscopes to measure the satellite's attitude angle deviation and angular velocity deviation to determine the satellite's attitude information; S23. Use a high-precision encoder and fiber optic gyroscope to measure the rotation angle and angular velocity of the pendulum mirror in two directions to determine the camera optical axis pointing information; S24. Introduce Kalman filtering to predict the motion law of the camera optical axis and determine the pointing information of the camera optical axis; S25. Substitute the motion law of the camera optical axis into the image shift calculation model described in S1 to calculate the line frequency.

5. The high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method according to claim 3, characterized in that, The TDI detector drive signal is updated in real time using the line frequency to adjust the imaging line frequency.

6. The high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method according to claim 1, characterized in that, The fixed deflection angle adjustment described in S3 includes selecting the fixed deflection angle adjustment amount and excluding the fixed deflection angle adjustment amount.

7. The high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method according to claim 6, characterized in that, The selected fixed deflection angle adjustment amount is: ， in, , where is the instantaneous value of the deflection angle of the i-th detector at imaging time t; n is the total number of detectors, and t is the effective imaging time.

8. The high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method according to claim 6, characterized in that, The amount of adjustment to exclude the fixed deflection angle is: ， Using the least squares method The dynamic deflection angle fitting curve is obtained by fitting. .

9. The high dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging method according to claim 6, characterized in that, The installation angle is: 。 10. A high-dynamic real-time bias-adjustment rheodynamic line frequency image shift compensation optical scanning imaging device, characterized in that, The device includes: The imaging mode selection and compensation parameter calculation module is used to perform high-dynamic vertical rail wide-area scanning imaging using a combination of vertical rail scanning and pitch return imaging modes, determine the satellite imaging motion law, and establish a high-precision multi-coordinate system object-image geometric mapping and image motion calculation model based on the satellite imaging motion law, and calculate the variation law of image motion compensation parameters; the variation law of image motion compensation parameters includes the variation law of detector line frequency and the variation law of yaw angle; The on-orbit adaptive line frequency module is used to measure satellite orbit information, attitude information, and camera optical axis pointing information through high-precision sensors, predict the camera optical axis motion law by filtering, and substitute it into the image shift calculation model to obtain the line frequency. A graded deflection angle adjustment module; used to achieve graded deflection angle adjustment based on the deflection angle variation law and the camera optical axis motion law, through fixed deflection angle adjustment, curve fitting and installation angle adjustment.

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