On-orbit tuning method for space remote sensing camera

Abstract

The invention relates to the technical field of space remote sensing camera in-orbit adjustment, in particular to a space remote sensing camera in-orbit adjustment and optimization method, which comprises the following steps of: firstly, testing in a static state after ensuring that the attitude of a space remote sensing camera is stable based on an area array working mode of a time delay integral linear array detector, and roughly adjusting the position of a secondary mirror through star observation; when the size and the shape of the obtained defocused spot are close to the size of a circular defocused spot and reach the minimum size, rough adjustment of a focusing position is started, and then fine adjustment of a secondary mirror position and the focusing position is carried out based on a blade edge target on the ground; and finally, the time delay integral linear array detector is tested in a push-broom state, and fine in-orbit tuning is carried out on the premise that it is confirmed that the TDI direction and the image motion speed are correct. According to the method, by setting the reasonable tuning steps, the tuning efficiency can be effectively improved, so that the tuning time is saved, and the consumption of on-orbit resources is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of on-orbit adjustment of space remote sensing cameras, and in particular relates to an on-orbit optimization method for a space remote sensing camera based on a time-delay integrated linear array detector. Background Art

[0002] After launching into orbit, the space remote sensing camera works in the space microgravity environment. During the entire development process, the space remote sensing camera will inevitably be affected by the ground gravity. As the aperture and focal length of the space remote sensing camera become larger and larger, the adverse effect of gravity on the installation and detection of the optical system is greatly magnified, resulting in the position accuracy of the reflector in the large-aperture and long-focal-length optical system becoming increasingly difficult to guarantee. When the space remote sensing camera reaches the best performance state through installation and detection under the ground gravity conditions, the optical system actually already includes the gravity deformation of each reflector and its supporting structure as well as the body of the space remote sensing camera. The space remote sensing camera will be affected by vibration and impact during the launch process. After entering orbit, the gravity deformation will be released in the space microgravity environment, resulting in changes in the position of each reflector in the optical system, which will cause a certain wave aberration in the optical system and affect the on-orbit imaging quality of the space remote sensing camera.

[0003] At present, the solution to gravity deformation is mainly based on the ground gravity unloading method, but this method is difficult to completely eliminate the influence of gravity deformation, and in the process of gravity unloading, it is easy to cause local stress in the space remote sensing camera, and it is difficult to ensure the effect of gravity unloading. Therefore, it is necessary to propose a new method to solve the technical problem of large-caliber space remote sensing camera installation and detection difficulties caused by gravity. In addition to the influence of ground gravity, environmental factors such as vibration and impact during the launch process and temperature changes on the orbit also have a great impact on the space remote sensing camera, which will cause the misalignment wave aberration of the space remote sensing camera after entering orbit to exceed the design requirements, affecting the imaging quality of the space remote sensing camera on orbit. Since the influence of these factors is somewhat random, simulation analysis can only be performed by estimating the limit of their misalignment.

[0004] The invention patent with publication number CN113093361A proposes an on-orbit adjustment method for a space camera. The ground processing steps of the space camera before launch include: (1) the temperature of the installation and experiment is kept consistent with the on-orbit design temperature; (2) reverse loading of gravity is performed, and the influence of gravity on the relative positions of the optical elements of the telephoto camera is analyzed through system simulation, and the adjustment range of the secondary mirror is estimated; (3) for the two postures of 0° and 180° when the camera is on the ground, the adjustment amount of the secondary mirror position caused by the influence of gravity is quantitatively measured; (4) before the camera is launched, the loading is performed in the opposite direction of the influence of gravity according to the adjustment amount measurement result, and the adjustment direction and adjustment amount of the secondary mirror position are pre-set; the ground verification steps of the secondary mirror adjustment include: (1) placing the camera according to the on-orbit posture, adjusting the ambient temperature to the on-orbit design temperature, measuring the wave aberration of the optical system, and adjusting the position of the secondary mirror to make the system wave aberration reach the optimal state; (2) flipping the camera 180 degrees based on the on-orbit posture, adjusting the ambient temperature to the on-orbit design temperature, measuring the wave aberration of the optical system, and adjusting the position of the secondary mirror. The position adjustment makes the system wave aberration reach the optimal state; the direction and range of the secondary mirror position adjustment are determined by this scheme; the steps of adjusting the secondary mirror on track include: (1) focusing by the climbing method to obtain the optimal focal plane position, that is, the focal plane position when the transfer function is maximum; (2) adjusting the secondary mirror position in the X direction to obtain the secondary mirror position in the X direction when the transfer function is maximum; (3) adjusting the secondary mirror position in the Y direction to obtain the secondary mirror position in the Y direction when the transfer function is maximum; (4) rotating the secondary mirror angle in the X direction to obtain the secondary mirror rotation angle in the X direction when the transfer function is maximum; (5) rotating the secondary mirror angle in the Y direction to obtain the secondary mirror rotation angle in the Y direction when the transfer function is maximum; at the same time, the judgment criteria for the optimal position and rotation angle on track are also introduced: shooting the target laid on the ground, performing fine image shift matching, real-time imaging of the ground target, adjusting the position of the secondary mirror, and calculating the transfer function value through target image analysis at different secondary mirror positions and rotation angles. The secondary mirror position and angle corresponding to the maximum value of the transfer function are the optimal position and rotation angle of the secondary mirror on track.

[0005] However, the patent does not take into account that image shift mismatch, defocus and wave aberration may all cause image blur. Specific means and judgment criteria are needed to separate the three and find out the causes of image blur in order to achieve the optimal in-orbit tuning of the space remote sensing camera. Summary of the invention

[0006] In view of this, the present invention aims to provide an on-orbit optimization method for a space remote sensing camera, so as to solve the problem that the patent with publication number CN113093361A cannot achieve on-orbit optimal state optimization of the space remote sensing camera.

[0007] To achieve the above object, the technical solution created by the present invention is implemented as follows: An on-orbit optimization method for a space remote sensing camera, the space remote sensing camera comprising a camera controller, an optical system, a time-delayed integrated linear array detector and an imaging processing unit, the optical system comprising a focusing mechanism and a secondary mirror adjustment mechanism, the camera controller being used to receive ground control instructions, control the focusing mechanism and the secondary mirror adjustment mechanism, set the working mode of the time-delayed integrated linear array detector and set the working mode of the imaging processing unit; The on-orbit tuning method includes the following steps: S1: Set the working mode of the time delay integration linear array detector to the planar array working mode through the camera controller, and use the secondary mirror adjustment mechanism to perform coarse adjustment of the secondary mirror through stargazing to obtain the optimal secondary mirror position range; S2: Maintaining the planar array working mode of the time delay integral linear array detector unchanged, after the secondary mirror is roughly adjusted, perform coarse focusing using the focusing mechanism through star observation to obtain the best focusing position range; S3: Maintaining the array working mode of the time delay integration linear array detector unchanged, performing a static modulation transfer function test on the edge target on the ground, fine-tuning the secondary mirror within the optimal secondary mirror position range, and obtaining the secondary mirror position corresponding to the maximum static modulation transfer function; S4: Maintaining the area array working mode of the time delay integral linear array detector unchanged, performing a static modulation transfer function test on the edge target on the ground, fine-tuning the focus position within the optimal focus position range, and obtaining the focus position corresponding to the maximum static modulation transfer function; S5: setting the working mode of the time delay integration linear array detector to the linear array working mode through the camera controller, performing a dynamic modulation transfer function test by observing the edge target on the ground, and comparing the dynamic modulation transfer function values ​​of two TDI directions, taking the direction with the larger dynamic modulation transfer function value as the TDI direction; S6: maintaining the linear array working mode of the time delay integration linear array detector unchanged, performing a dynamic modulation transfer function test on the edge target on the ground, performing positive and negative deviations on the image motion speed, and taking the speed corresponding to the maximum value of the dynamic modulation transfer function as the image motion speed; S7: If, in the linear array working mode, the image in the vertical track direction is clear while the image in the along-track direction is blurred, and in the planar array working mode, the images in both the along-track and vertical track directions are clear, then it is determined that the image blur is caused by opposite TDI directions or image motion speed mismatch; if, in the linear array working mode, the images in both the along-track and vertical track directions are clear, then it is determined that the TDI direction is correct or the image motion speed matches; if, in the planar array working mode, the images in both the along-track and vertical track directions are blurred, then it is determined that the image blur is caused by additional factors.

[0008] Furthermore, the working mode of the time-delayed integrated linear array detector is set to the planar array working mode through the camera controller, and a static modulation transfer function test is performed on the edge target on the ground through star observation to evaluate the optimal secondary mirror position and focal plane position.

[0009] Furthermore, when the imaging processing unit is in a normal working mode, the image data is conditioned and the conditioned image data is output; when the imaging processing unit is in a stargazing tuning mode, the diffuse light spots of the star point targets are counted, the center of the star point targets is used as the coordinate origin, the grayscale value in the diffuse light spot is multiplied by the distance between the diffuse light spot and the coordinate origin for accumulation, and the calculation result is fed back to the camera controller; when the imaging processing unit is in a ground object viewing tuning mode, the dynamic modulation transfer function and the static modulation transfer function are calculated based on the knife edge method, and the calculation result is fed back to the camera controller.

[0010] Further, additional factors are defocus or wave aberration exceeding a threshold.

[0011] Furthermore, the constraint relationship between the working wavelength λ, focal ratio F, and pixel size a of the optical system is: .

[0012] Compared with the prior art, the invention can achieve the following beneficial effects: (1) Improve tuning efficiency by setting reasonable tuning steps, thereby saving tuning time and reducing the consumption of on-orbit resources; (2) By switching the area array and linear array working modes of the time delay integrated linear array detector, it is possible to quickly determine whether there is an image shift mismatch, thereby quickly locating the tuning problem; (3) By switching between different working states of the imaging processing unit, relevant results can be calculated quickly on orbit, without having to wait for the data to be transmitted to the ground for processing and calculation before the next adjustment operation can be performed. This increases the cycle speed of the tuning and reduces the cycle period, thereby improving the tuning efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 It is a schematic diagram of the structure of a space remote sensing camera according to an embodiment of the present invention.

[0014] Explanation of reference numerals: camera controller 1 , optical system 2 , time-delay-integrated linear array detector 3 , and imaging processing unit 4 . DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0016] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0017] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0018] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0019] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0020] The present invention provides an on-orbit optimization method for a space remote sensing camera. The structure of the space remote sensing camera is as follows: Figure 1As shown, the space remote sensing camera includes a camera controller 1, an optical system 2, a time-delayed integrated linear array detector 3 and an imaging processing unit 4; wherein the optical system 2 includes a focusing mechanism and a secondary mirror adjustment mechanism, and the camera controller 1 is used to receive control instructions from the ground and perform different operation controls, including controlling the focusing mechanism and the secondary mirror adjustment mechanism, realizing secondary mirror adjustment and focusing operations, setting the working mode of the time-delayed integrated linear array detector and setting the working mode of the imaging processing unit.

[0021] In a specific embodiment, the camera controller 1 adopts an architecture based on DSP+FPGA and stepper motor; the optical system 2 adopts an off-axis three-mirror adjustment secondary mirror form; the time-delayed integrated linear array detector 3 adopts a focal plane component based on a TDICCD detector or a TDICMOS detector; and the imaging processing unit 4 is implemented using FPGA of Xilinx or Fudan Microelectronics.

[0022] The working wavelength λ, focal ratio F, and pixel size a of the optical system 2 need to satisfy the following constraint relationship: .

[0023] The purpose of this constraint is to ensure that the size of the diffuse spot is large enough, at least larger than 3 pixels; if the size of the diffuse spot is too small, the accuracy of calculating the centroid position of the spot will be reduced; if the size of the diffuse spot is only one pixel, the centroid position of the spot cannot be subdivided; if the size of the diffuse spot is two pixels, the accuracy of the subdivision is low.

[0024] The purpose of the present invention is to achieve the separation of image shift mismatch, defocus and wave aberration. The time-delayed integrated linear array detector 3 can avoid the influence of image shift mismatch in the area array working mode. By comparing the area array working mode and the linear array working mode, it can be judged whether there is image shift mismatch. Defocus and wave aberration can be separated by stargazing; if the secondary mirror is adjusted in the stargazing mode, the diffuse spot size of the star point can become smaller and the shape of the star point becomes more symmetrical, then there is still wave aberration; if the focus is adjusted in the stargazing mode, the size of the star point can be made smaller, then there is defocus.

[0025] The on-orbit optimization method of a space remote sensing camera provided by the present invention comprises the following steps: S1: Set the working mode of the time-delayed integrated linear array detector to the planar array working mode through the camera controller, and use the secondary mirror adjustment mechanism to perform coarse adjustment of the secondary mirror through stargazing to obtain the optimal secondary mirror position range.

[0026] When adjusting the secondary mirror in stargazing mode, if the diffuse spot size of the star point can become smaller and the shape of the star point becomes more symmetrical, then wave aberration still exists. During the adjustment of the secondary mirror, the position where the diffuse spot size of the star point is the smallest and the shape of the star point is the most symmetrical is recorded, which is considered the best secondary mirror position.

[0027] S2: Maintain the planar array working mode of the time-delayed integrated linear array detector unchanged. After the coarse adjustment of the secondary mirror is completed, the coarse focusing is performed by using the focusing mechanism through star observation to obtain the best focusing position range.

[0028] The array working mode based on the time-delayed integrated linear array detector ensures that the space remote sensing camera is tested in a static state after its posture is stable. The secondary mirror state is roughly adjusted through stargazing. When the obtained diffuse spot size shape is close to a circular diffuse spot size and reaches the minimum, the coarse focusing of the optical system is started.

[0029] If the focus adjustment in stargazing mode can make the star point smaller, then there is defocus. During the focusing process, record the position where the star point diffuse spot size is the smallest, which is the best focusing position.

[0030] S3: Maintaining the planar array working mode of the time-delayed integrated linear array detector unchanged, conduct a static modulation transfer function test on the edge target on the ground, fine-tune the secondary mirror within the optimal secondary mirror position range, and obtain the secondary mirror position corresponding to the maximum static modulation transfer function.

[0031] In the stargazing mode, a large range of secondary mirror position adjustment is performed. After obtaining the best position of the secondary mirror coarse adjustment, fine adjustment of the secondary mirror position is performed. The adjustment range is less than 1 / 10 of the coarse adjustment range, and the modulation amount each time is less than 1 / 10 of the coarse adjustment. After each adjustment, a static modulation transfer function test is performed, and the position of the maximum static modulation transfer function is recorded, which is regarded as the best secondary mirror position.

[0032] S4: Maintaining the area array working mode of the time delay integral linear array detector unchanged, performing a static modulation transfer function test on the edge target on the ground, fine-tuning the focus position within the optimal focusing position range, and obtaining the focusing position corresponding to the maximum static modulation transfer function.

[0033] In the stargazing mode, adjust the focal plane position over a large range. After obtaining the best focal plane position for coarse adjustment, make fine adjustments to the focal plane position. The adjustment range is less than 1 / 10 of the coarse adjustment range, and the modulation amount each time is less than 1 / 10 of the coarse adjustment. After each adjustment, test the static modulation transfer function. Record the position of the maximum static modulation transfer function, which is considered the best focal plane position.

[0034] The working mode of the time delay integral linear array detector is set to the planar array working mode through the camera controller, and a static modulation transfer function test is performed on the edge target on the ground through star observation. When the static modulation transfer function corresponding to the secondary mirror position is the largest, it is regarded as the optimal secondary mirror position; when the static modulation transfer function corresponding to the focal plane position is the largest, it is regarded as the optimal focal plane position.

[0035] S5: The working mode of the time delay integration linear array detector is set to the linear array working mode through the camera controller, and a dynamic modulation transfer function test is performed by observing the edge target on the ground. By comparing the dynamic modulation transfer function values ​​of two TDI directions, the direction with a larger dynamic modulation transfer function value is taken as the TDI direction.

[0036] The two TDI directions refer to the same direction as the setting instruction execution and the opposite direction as the setting instruction execution. By comparing the imaging effects of the two TDI directions, it is determined whether there is a TDI direction error.

[0037] S6: Maintain the linear array working mode of the time delay integration linear array detector unchanged, perform dynamic modulation transfer function test on the edge target on the ground, make positive and negative deviations on the image motion speed, and take the speed corresponding to the maximum value of the dynamic modulation transfer function as the image motion speed.

[0038] The premise of obtaining a high dynamic modulation transfer function is image shift matching, that is, making the line frequency of charge transfer the same as the image shift speed on orbit. The image shift speed is calculated based on the position and attitude of the satellite in space. The calculation process is complicated, and there may be deviations in the satellite position and attitude measured on orbit, which leads to a deviation between the calculated line frequency and the actual image shift speed. Therefore, in order to obtain a higher dynamic modulation transfer function and obtain the best imaging effect, the line frequency corresponding to the calculated image shift speed is deviated positively or negatively. That is, based on the line frequency corresponding to the calculated image shift speed, a comparison test is performed within a certain range of positive and negative deviations to see whether the imaging effect will be better after the deviation.

[0039] For example: negative bias 60%, negative bias 50%, negative bias 40%, negative bias 30%, negative bias 20%, negative bias 10%, negative bias 5%, calculated value, positive bias 5%, positive bias 10%, positive bias 20%, positive bias 30%, positive bias 40%, positive bias 50%, positive bias 60%.

[0040] S7: If, in the linear array working mode, the image in the vertical track direction is clear while the image in the along-track direction is blurred, and in the planar array working mode, the images in both the along-track and vertical track directions are clear, then it is determined that the image blur is caused by opposite TDI directions or image motion speed mismatch; if, in the linear array working mode, the images in both the along-track and vertical track directions are clear, then it is determined that the TDI direction is correct or the image motion speed matches; if, in the planar array working mode, the images in both the along-track and vertical track directions are blurred, then it is determined that the image blur is caused by additional factors.

[0041] The vertical track direction refers to the scanning direction perpendicular to the space track or perpendicular to the flight direction; the along-track direction refers to the scanning direction parallel to the space track or the flight direction.

[0042] The imaging effects in two dimensions are used to determine whether the TDI direction is opposite or the image speed is mismatched: When the time delay integrated linear array detector is in the linear array working mode, the image in the vertical track direction is clear (dynamic modulation transfer function is high), while the image in the along-track direction is blurred (dynamic modulation transfer function is low), and the time delay integrated linear array detector is in the planar array working mode, the images in both the along-track direction and the vertical track direction are clear (static modulation transfer function is high), it is determined that the image blur is caused by the opposite TDI direction or the image speed mismatch; When the time delay integration linear array detector is in the linear array working mode, the images in the along-track direction and the vertical-track direction are clear (the dynamic modulation transfer function is high), then it is determined that the TDI direction is correct or the image motion speed is matched, and there is no possibility of the opposite TDI direction or image motion speed mismatch; When the time delay integration linear array detector is in the area array working mode, the images in the along-track direction and the vertical-track direction are blurred (the static modulation transfer function is low), it is determined that the image blur is caused by additional factors other than the opposite TDI direction or the image speed mismatch. The additional factors refer to two factors, one is defocus, and the other is excessive wave aberration that exceeds the threshold.

[0043] It should be noted that imaging in the area array working mode belongs to the static modulation transfer function, and imaging in the linear array working mode belongs to the dynamic modulation transfer function.

[0044] By switching between the area array working mode and the linear array working mode of the time delay integral linear array imaging focal plane, it is possible to quickly determine whether there is an image shift mismatch effect, thereby quickly locating the tuning problem.

[0045] According to different working modes of the imaging processing unit, the different working states of the imaging processing unit are switched: When the imaging processing unit is in a normal working mode, the image data is conditioned and the conditioned image data is output; When the imaging processing unit is in the stargazing tuning mode, the diffuse light spots of the star point target are counted, the center of the star point target is used as the coordinate origin, the gray value in the diffuse light spot of the star point target is multiplied by the distance between the diffuse light spot of the star point target and the coordinate origin of the diffuse light spot of the star point target, and the calculation result is fed back to the camera controller; When the imaging processing unit is in the ground object optimization mode, the modulation transfer function is calculated based on the knife edge method, and the calculation result is fed back to the camera controller.

[0046] By switching different working states of the imaging processing unit, relevant results can be calculated quickly on orbit, without waiting for the data to be transmitted to the ground for processing and calculation before making the next adjustment operation, thereby increasing the cycle speed of tuning, reducing the cycle period, and thus improving the tuning efficiency.

[0047] The present invention can effectively improve the tuning efficiency by setting reasonable tuning steps, thereby saving tuning time and reducing the consumption of on-orbit resources.

[0048] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0049] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An on-orbit optimization method for a space remote sensing camera, the space remote sensing camera comprising a camera controller, an optical system, a time-delayed integrated linear array detector and an imaging processing unit, the optical system comprising a focusing mechanism and a secondary mirror adjustment mechanism, the camera controller being used to receive control instructions from the ground, control the focusing mechanism and the secondary mirror adjustment mechanism, set the working mode of the time-delayed integrated linear array detector and set the working mode of the imaging processing unit; characterized in that: The on-orbit tuning method includes the following steps: S1: Set the working mode of the time delay integration linear array detector to the planar array working mode through the camera controller, and use the secondary mirror adjustment mechanism to perform coarse adjustment of the secondary mirror through stargazing to obtain the optimal secondary mirror position range; S2: Maintaining the planar array working mode of the time delay integral linear array detector unchanged, after the secondary mirror is roughly adjusted, perform coarse focusing using the focusing mechanism through star observation to obtain the best focusing position range; S3: Maintaining the array working mode of the time delay integration linear array detector unchanged, performing a static modulation transfer function test on the edge target on the ground, fine-tuning the secondary mirror within the optimal secondary mirror position range, and obtaining the secondary mirror position corresponding to the maximum static modulation transfer function; S4: Maintaining the area array working mode of the time delay integral linear array detector unchanged, performing a static modulation transfer function test on the edge target on the ground, fine-tuning the focus position within the optimal focus position range, and obtaining the focus position corresponding to the maximum static modulation transfer function; S5: Setting the working mode of the time delay integration linear array detector to the linear array working mode through the camera controller, performing a dynamic modulation transfer function test by observing the edge target on the ground, and comparing the dynamic modulation transfer function values ​​of two TDI directions, taking the direction with the larger dynamic modulation transfer function value as the TDI direction; S6: maintaining the linear array working mode of the time delay integration linear array detector unchanged, performing a dynamic modulation transfer function test on the edge target on the ground, performing positive and negative deviations on the image motion speed, and taking the speed corresponding to the maximum value of the dynamic modulation transfer function as the image motion speed; S7: If, in the linear array working mode, the image in the vertical track direction is clear while the image in the along-track direction is blurred, and in the planar array working mode, the images in both the along-track and vertical track directions are clear, then it is determined that the image blur is caused by opposite TDI directions or image motion speed mismatch; if, in the linear array working mode, the images in both the along-track and vertical track directions are clear, then it is determined that the TDI direction is correct or the image motion speed matches; if, in the planar array working mode, the images in both the along-track and vertical track directions are blurred, then it is determined that the image blur is caused by additional factors.

2. The on-orbit optimization method of a space remote sensing camera according to claim 1, characterized in that: The working mode of the time delay integration linear array detector is set to the planar array working mode through the camera controller. The static modulation transfer function test of the edge target on the ground is carried out through star observation to evaluate the optimal secondary mirror position and focal plane position.

3. The on-orbit tuning method of a space remote sensing camera according to claim 1, characterized in that: When the imaging processing unit is in the normal working mode, the image data is conditioned and the conditioned image data is output; when the imaging processing unit is in the star viewing tuning mode, the diffuse light spots of the star point targets are counted, the center of the star point target is used as the coordinate origin, the grayscale value in the diffuse light spot is multiplied by the distance between the diffuse light spot and the coordinate origin for accumulation, and the calculation result is fed back to the camera controller; when the imaging processing unit is in the ground viewing tuning mode, the dynamic modulation transfer function and the static modulation transfer function are calculated based on the knife edge method, and the calculation result is fed back to the camera controller.

4. The on-orbit tuning method of a space remote sensing camera according to claim 1, characterized in that: Additional factors are defocus or wave aberration exceeding a threshold.

5. The on-orbit tuning method of a space remote sensing camera according to claim 1, characterized in that: The constraint relationship between the working wavelength λ, focal ratio F, and pixel size a of the optical system is: .

Images