Inter-satellite signal stable pointing method and system for ensuring ranging payload narrow beam alignment

Abstract

The application provides an inter-satellite signal stable pointing method and system for ensuring ranging load narrow beam alignment, and belongs to the field of spacecraft control. Both of the two stars in the method and system are configured with ranging loads; an inter-satellite pointing attitude is established when the satellite is flying; initial values of an attitude capture correction value, an attitude interference correction value and a capture error correction value are set as 0; when both the capture success signal and the interference success signal are successful in the flying process, the interference error signal is used to update the attitude interference correction value and the capture error correction value; when the capture success signal is successful and the interference success signal is unsuccessful, the current latest capture error correction value is used to correct the current capture error signal, and the corrected capture error signal is used to update the attitude correction value; according to the inter-satellite pointing theoretical value, the attitude measurement value provided by the satellite attitude determination, the capture or interference correction value of the attitude and the interference error signal effectiveness, the stable command control of the inter-satellite signal is completed.

Description

Technical Field

[0001] This invention relates to the field of spacecraft control, and in particular to a method and system for ensuring stable pointing of inter-satellite signals to ensure narrow beam alignment of ranging payloads. It is applicable to all spacecraft equipped with inter-satellite ranging payloads such as laser interferometers that have high-precision inter-satellite acquisition and stable pointing requirements. Background Technology

[0002] Formation satellites using laser interferometers and other equipment for inter-satellite ranging require high precision in inter-satellite pointing control. This necessitates mutual acquisition under extremely narrow laser interferometer beam conditions, and ensuring stable and continuous tracking after acquisition. Current technology achieves inter-satellite pointing control for laser interferometer operation by calculating the inter-satellite pointing angle through high-precision orbit extrapolation of the two satellites and controlling the satellites to track this angle. However, due to limitations in orbit extrapolation accuracy, the precision of inter-satellite pointing control is difficult to improve, making it impossible to guarantee stable and continuous tracking by the laser interferometer. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method and system for stable pointing of inter-satellite signals to ensure narrow beam alignment of ranging payload. Through mutual calibration and coordinated operation of ranging payload and attitude control, high-precision inter-satellite acquisition and stable pointing control of satellite ranging signals are achieved.

[0004] The technical solution of this invention is: a method for ensuring stable pointing of inter-satellite signals while maintaining narrow beam alignment of ranging payloads. The method involves two satellites equipped with ranging payloads, with the ranging payload pointing reference coaxial with the X-axis of the satellite's own system. The ranging payload is equipped with an acquisition sensor, a rotating mirror, and an interferometer. The acquisition sensor provides a successful acquisition signal and acquisition error information for the incident light. The rotating mirror performs a two-dimensional rotation to adjust the direction of the outgoing light so that the outgoing light and the incident light are aligned and interfere. The interferometer provides a successful interference signal and interference error information. During satellite flight, an inter-satellite pointing attitude is established, which is the attitude in which the X-axis of the two satellites are aligned with each other and point towards the position of the other satellite. The initial values ​​for attitude acquisition correction, attitude interference correction, and acquisition error correction are set to 0. During flight, the system continuously monitors the validity of signals from the ranging payload. When both the acquisition and interference success signals are successful, the attitude interference correction and acquisition error correction values ​​are updated using the interference error signal. When the acquisition success signal is successful but the interference success signal is unsuccessful, the current acquisition error signal is corrected using the latest acquisition error correction value, and the attitude acquisition correction value is updated using the corrected acquisition error signal. Based on the theoretical value of inter-satellite pointing, the attitude measurement value provided by on-board attitude determination, the attitude acquisition or interference correction value, and the effectiveness of the interference error signal, the stable command control of the inter-satellite signal is completed.

[0005] Preferably, the attitude interferometry correction values ​​are updated using interferometry error information. These values ​​include pitch and yaw attitude interferometry correction values, specifically:

[0006] in, , These are the pitch and yaw attitude interference correction values, respectively. and These are the elevation interference correction coefficients for the current cycle and the previous cycle, respectively. and These are the yaw interference correction coefficients for the current cycle and the previous cycle, respectively. For the current star time, Forgetting factor, and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. and These are the covariance matrices of the interference errors for the current period and the previous period, respectively; the others are intermediate variables in the calculation process.

[0007] Preferably, the acquisition error correction value includes pitch acquisition error correction value and yaw acquisition error correction value, and the calculation formula is as follows:

[0008] in, and These are the pitch acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the yaw acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the values ​​for capturing pitch error and yaw error, respectively. and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. Correct the filter coefficients to capture the error.

[0009] Preferably, the attitude acquisition correction values ​​are updated using the acquisition error signal. The attitude acquisition correction values ​​include pitch and yaw attitude acquisition correction values, and the calculation formula is as follows:

[0010] in, , These are the pitch and yaw attitude acquisition correction values, respectively. and These are the capture error covariance matrices for the current period and the previous period, respectively. and These are the pitch acquisition correction coefficients for the current cycle and the previous cycle, respectively. and These are the yaw capture correction coefficients for the current cycle and the previous cycle, respectively. For the current star time, Forgetting factor, and These are the values ​​for capturing pitch error and yaw error, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. , These are the latest pitch and yaw acquisition error correction values, respectively; the others are intermediate variables in the calculation process.

[0011] A stable pointing system for inter-satellite signals that ensures narrow beam alignment of ranging payloads includes a ranging payload, a correction module, and an attitude control module configured on two satellites. The ranging payload pointing reference is coaxial with the X-axis of the satellite system. The ranging payload is equipped with an acquisition sensor, a rotating mirror, and an interferometer. The acquisition sensor provides a signal indicating successful acquisition of the incident light and information on the acquisition error. The rotating mirror performs a two-dimensional rotation to adjust the direction of the outgoing light so that the outgoing light and the incident light are aligned and interfere with each other. The interferometer provides a signal indicating successful interference and information on the interference error. The attitude control module establishes an inter-satellite pointing attitude during satellite flight, which is the attitude in which the X-axis of the two satellites are aligned with each other and point towards the position of the other satellite. The correction module performs mutual correction of the three based on the status of the successful acquisition signal and the successful interference signal, combined with the theoretical inter-satellite pointing value provided by the ground, the acquisition error information provided by the ranging payload, and the interference error information, and obtains the attitude acquisition or interference correction value, which is then sent to the attitude control module. The attitude control module, based on the status of successful acquisition signal, successful interference signal, and the validity of interference information, and combining the theoretical value of inter-satellite pointing, the attitude measurement value provided by on-board attitude determination, and the attitude acquisition or interference correction value, completes the stable command control of inter-satellite signals.

[0012] Preferably, the correction module is implemented in the following manner: The initial values ​​for attitude capture correction and attitude interference correction are set to 0; the attitude capture correction and attitude interference correction values ​​are updated based on the real-time received ranging load information. When both the acquisition success signal and the interference success signal are successful, the inter-satellite pointing theoretical value is corrected using the interference error information, and the attitude interference correction value is calculated; at the same time, the acquisition error information is corrected using the interference error information to obtain the acquisition error correction value; When the acquisition success signal is successful but the interference success signal is unsuccessful, the acquisition error information is used to correct the theoretical value of inter-satellite pointing, and the attitude acquisition correction value is obtained.

[0013] Preferably, the attitude interference correction value is calculated using the interference error information to calculate the theoretical value of inter-satellite pointing:

[0014] in, , These are the pitch and yaw attitude interference correction values, respectively. and These are the elevation interference correction coefficients for the current cycle and the previous cycle, respectively. and These are the yaw interference correction coefficients for the current cycle and the previous cycle, respectively. For the current star time, Forgetting factor, and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. and These are the covariance matrices of the interference errors for the current period and the previous period, respectively; the others are intermediate variables in the calculation process. The formula for calculating the capture error correction value is as follows:

[0015] in, and These are the pitch acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the yaw acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the values ​​for capturing pitch error and yaw error, respectively. and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. Correct the filter coefficients to capture the error.

[0016] Preferably, the attitude acquisition correction value is calculated using the acquisition error information to calculate the theoretical value of inter-satellite pointing:

[0017] in, , These are the pitch and yaw attitude acquisition correction values, respectively. and These are the capture error covariance matrices for the current period and the previous period, respectively. and These are the pitch acquisition correction coefficients for the current cycle and the previous cycle, respectively. and These are the yaw capture correction coefficients for the current cycle and the previous cycle, respectively. For the current star time, Forgetting factor, and These are the values ​​for capturing pitch error and yaw error, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. , These are the latest pitch and yaw acquisition error correction values, respectively; the others are intermediate variables in the calculation process.

[0018] Preferably, the validity of the inter-satellite pointing theoretical value provided by the ground, the acquisition error information provided by the ranging payload, and the interferometric error information are combined to determine the effectiveness of the interferometric error information. The specific operation is as follows:

[0019] For valid judgment information , , , , , Perform the calculation:

[0020] If there is Simultaneously satisfy, or If both conditions are met, the interference error information for this period is invalid; otherwise, the interference error information for this period is valid. These are the upper and lower thresholds for judging pitch effectiveness, with values ​​of 20~30urad and 5~15urad, respectively. These are the upper and lower thresholds for judging yaw effectiveness, with values ​​of 20~30urad and 5~15urad, respectively. and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. , These are the latest pitch and yaw acquisition error correction values. , These are the pitch and yaw attitude interference correction values, respectively.

[0021] Preferably, the acquisition error information is the pointing deviation information provided by the acquisition sensor, including two parts: acquisition pitch error and acquisition yaw error. Theoretically, the magnitude and direction of the attitude pitch control error and yaw control error are the same as those when the on-board target pointing angle calculation deviation and star-sensor attitude determination deviation are not considered. The interference error information is the pointing deviation information provided by the interference sensor, including two parts: interference pitch error and interference yaw error. Theoretically, the magnitude and direction of the attitude pitch control error and yaw control error are the same as those when the on-board target pointing angle calculation deviation and star-sensor attitude determination deviation are not considered.

[0022] The advantages of this invention compared to the prior art are: (1) The attitude control based on the theoretical value of inter-satellite pointing creates conditions for inter-satellite capture of ranging loads such as laser interferometers. When the ranging load captures the optical signal, it uses the error information of the capture sensor to perform inter-satellite pointing control, which accelerates the process of the ranging load establishing inter-satellite interference. After the ranging load establishes inter-satellite interference, it uses the error information of the interference sensor to perform inter-satellite pointing control, which ensures high-precision inter-satellite interference tracking of the ranging load. (2) This invention uses real-time mutual verification of three types of data: inter-satellite pointing theoretical value, acquisition sensor error information and interference sensor error information provided by ranging payload, to identify and eliminate abnormal data in a timely and accurate manner, thereby avoiding abnormal data from being introduced into inter-satellite pointing control and causing attitude fluctuations, which could lead to a decrease in the data quality of ranging payload or even optical path interruption. (3) This invention improves the stability of high-precision inter-satellite pointing control by using three types of data—the theoretical value of inter-satellite pointing, the error information of the capture sensor provided by the interferometer, and the error information of the interferometer sensor—to mutually correct each other. When the high-precision interferometer sensor data is valid, it is used for inter-satellite pointing control. When the data is invalid, it automatically and smoothly switches to inter-satellite pointing control using the capture sensor data without disturbance, thus ensuring high-precision, stable, and continuous tracking of the ranging payload. Attached Figure Description

[0023] Figure 1 This is a flowchart of an inter-satellite signal stable pointing method for ensuring narrow beam alignment of ranging payload according to the present invention. Detailed Implementation

[0024] This invention provides a method for ensuring stable pointing of inter-satellite signals while maintaining narrow beam alignment of ranging payloads.

[0025] Example 1: A binary constellation of satellites operates in a circular orbit at an altitude of 500 kilometers, with the two satellites approximately 200 kilometers apart. Both are equipped with laser interferometers, whose pointing axes are coaxial with the satellites' own X-axis. During flight, the satellites are required to establish an inter-satellite pointing attitude, meaning the X-axis of both satellites is aligned with the other satellite's position to meet the operational requirements of the laser interferometers. The laser interferometers consist of a capture sensor, a rotating mirror, and an interference sensor. The capture sensor provides a signal indicating successful capture of the incident light and capture error information. The rotating mirror performs a two-dimensional rotation to adjust the direction of the outgoing light, aligning it with the incident light to cause interference. The interference sensor provides a signal indicating successful interference and interference error information. The capture error information, provided by the capture sensor, includes both capture pitch error and capture yaw error. Theoretically, these errors are identical in magnitude and direction to the attitude pitch control error and yaw control error calculated without considering on-board target pointing angle deviations and star-sensor attitude determination deviations. Interference error information is pointing deviation information provided by the interferometric sensor, including two parts: interferometric pitch error and interferometric yaw error. Theoretically, the magnitude and direction of the attitude pitch control error and yaw control error are the same as those when the on-board pointing angle calculation deviation and star-sensor attitude determination deviation are not considered.

[0026] Based on the above introduction, the present invention provides a method for stable pointing of inter-satellite signals to ensure narrow beam alignment of ranging payloads. When the satellite is in flight, it establishes an inter-satellite pointing attitude, that is, the attitude in which the X-axis of the two satellites are aligned with each other and pointing to the position of the other satellite. The initial values ​​for attitude acquisition correction, attitude interference correction, and acquisition error correction are set to 0. During flight, the system continuously monitors the validity of signals from the ranging payload. When both the acquisition and interference success signals are successful, the attitude interference correction and acquisition error correction values ​​are updated using the interference error signal. When the acquisition success signal is successful but the interference success signal is unsuccessful, the current acquisition error signal is corrected using the latest acquisition error correction value, and the attitude acquisition correction value is updated using the corrected acquisition error signal. Based on the theoretical value of inter-satellite pointing, the attitude measurement value provided by on-board attitude determination, the attitude acquisition or interference correction value, and the effectiveness of the interference error signal, the stable command control of the inter-satellite signal is completed.

[0027] To provide a more detailed explanation, let's take the aforementioned satellite formation as an example, such as... Figure 1 As shown, the content of this invention will be described from a system perspective: This invention accelerates the process of establishing inter-satellite interference by using the error information of the capture sensor when the ranging payload captures an optical signal during flight to perform inter-satellite pointing control. After the ranging payload establishes inter-satellite interference, it uses the error information of the interference sensor to perform inter-satellite pointing control, ensuring high-precision inter-satellite interference tracking of the ranging payload. For clarity, different tracking modes are described below, and the information provided by the ranging payload is updated in the correction module.

[0028] 1. Attitude control module The attitude control module makes a judgment: if the ranging payload gives a failed acquisition signal, the attitude control uses the attitude theoretical value tracking mode, and the ranging payload uses the scanning mode; otherwise, if the acquisition success signal is successful but the interferometry success signal is unsuccessful, the attitude control uses the attitude acquisition correction tracking mode, and the ranging payload uses the coarse tracking mode; otherwise, if both the acquisition success signal and the interferometry success signal are successful but the interferometry information validity is determined to be invalid, the attitude control uses the attitude acquisition correction tracking mode, and the ranging payload uses the coarse tracking mode; otherwise, if both the acquisition success signal and the interferometry success signal are successful and the interferometry information validity is determined to be valid, the attitude control uses the attitude interferometry correction tracking mode, and the ranging payload uses the fine tracking mode.

[0029] (1) Attitude theoretical value tracking mode The attitude theoretical value tracking mode uses the inter-satellite pointing theoretical value provided by the ground as the pointing target for attitude control, and uses the attitude measurement values ​​provided by on-board attitude determination such as star-sensor attitude determination. The attitude control error is calculated by combining the two, and the attitude control error is controlled to be close to 0 through attitude control. The specific operation is as follows.

[0030] The theoretical inter-satellite pointing values ​​provided by the ground include theoretical pitch pointing values. and yaw direction theoretical value Inter-satellite pointing deviation is only related to pitch and yaw attitude, therefore the theoretical value of roll pointing is... The default value is 0. The three-axis attitude measurements provided by conventional on-board attitude determination methods such as star-aware attitude determination include roll attitude measurements. Pitch attitude measurement value Yaw attitude measurement value and rolling angular velocity measurements Pitch angular velocity measurement value Yaw angular velocity measurement value Calculate the attitude control error:

[0031] in , , These are the control errors for roll, pitch, and yaw attitude angles, respectively. , , These are the control errors for roll, pitch, and yaw attitude angular velocities, respectively.

[0032] Based on the attitude angle control error and attitude angular velocity control error, the attitude control torque is calculated using a control law and implemented by the actuator. Specifically, conventional attitude control methods can be used, or the following approach can be referenced.

[0033] The desired control torque is calculated using a control law such as PD or PID based on the attitude control variable and the attitude angular velocity control variable. Here, we use the PD control law: ,in 3 1-dimensional array, and All are 3 3D control coefficients and These are the vector forms of the three-axis attitude control quantity and the three-axis attitude angular velocity control quantity, respectively. PD or PID control laws are fundamental methods in control system design. The control coefficients must ensure control stability and other constraints. For specific methods, refer to works such as Hu Shousong's "Principles of Automatic Control." When the desired control torque is implemented by the actuator, the control signal given to the actuator is determined by the specific actuator type and its installation method. For example, a satellite may have a momentum wheel installed in each of its three positive axes. The voltage-torque conversion coefficient of the momentum wheel is... Then, without considering friction compensation, the momentum wheel control voltage is calculated from the desired control torque. The formula is: ,in 3 A 1D array will control the voltage. The output is sent to three momentum wheels, which drive the momentum wheels to generate corresponding control torques. For details, please refer to the chapter on actuators in "Satellite Attitude Dynamics and Control" edited by Academician Tu Shancheng.

[0034] (2) Attitude capture and correction tracking mode The attitude acquisition and correction tracking mode uses the theoretical inter-satellite pointing value provided by the ground as the pointing target for attitude control, the attitude measurement value provided by on-board attitude determination such as star-sensor attitude determination, and the acquisition and correction value provided by the correction module of this method. The attitude control error is calculated by combining these three values, and the attitude control error is controlled to near zero through attitude control. The specific operation is as follows.

[0035] Calculate attitude control error:

[0036] in , These are the pitch and yaw attitude capture correction values, respectively. The initial values ​​are both 0, and the values ​​are updated in the correction module of this method.

[0037] Based on the attitude angle control error and attitude angular velocity control error, the attitude control torque is calculated using a control law and implemented by the actuator. For specific operation details, refer to the attitude theoretical value tracking mode.

[0038] (3) Attitude Interference Correction Tracking Mode The attitude interferometry correction tracking mode uses the theoretical inter-satellite pointing value provided by the ground as the pointing target for attitude control, the attitude measurement value provided by on-board attitude determination such as star-sensor attitude determination, and the interferometry correction value provided by the correction module of this method. The attitude control error is calculated by combining these three values, and the attitude control error is controlled to near zero through attitude control. The specific operation is as follows.

[0039] Calculate attitude control error:

[0040] in , These are the pitch and yaw attitude interference correction values, respectively. The initial values ​​are both 0, and the values ​​are updated in the correction module of this method.

[0041] Based on the attitude angle control error and attitude angular velocity control error, the attitude control torque is calculated using a control law and implemented by the actuator. For specific operation details, refer to the attitude theoretical value tracking mode.

[0042] 2. Calibration Module The calibration module performs mutual calibration based on the theoretical inter-satellite pointing value provided by the ground, the acquisition error information provided by the ranging payload, and the interferometric error information. The specific operation is as follows.

[0043] When both the acquisition success signal and the interference success signal are successful, the attitude interference correction value is calculated using the interference error information to evaluate the theoretical value of inter-satellite pointing:

[0044] in For the current star time, The forgetting factor is typically set between 0.95 and 0.99. and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. and These are the covariance matrices of the interference errors for the current period and the previous period, respectively. The initial values ​​can be taken as follows: , and These are the elevation interference correction coefficients for the current cycle and the previous cycle, respectively, with initial values ​​set to... , and These are the yaw interferometry correction coefficients for the current and previous cycles, respectively, with initial values ​​set to... All others are intermediate variables in the calculation process. The correction calculation part of this invention does not consider whether the interference error information is valid. Since filtering is used in the correction process, it has a certain anti-interference ability on the one hand, and the validity judgment of the interference error information uses the filtering result on the other hand, which may affect the correctness of the validity judgment before the filtering converges.

[0045] When both the acquisition success signal and the interference success signal are successful, the acquisition error correction value is calculated using the interference error information:

[0046] in and These are the pitch acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the yaw acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the values ​​for capturing pitch error and yaw error, respectively. To capture error correction filter coefficients, values ​​between 0.02 and 0.2 are typically chosen.

[0047] When the acquisition success signal is successful but the interference success signal is unsuccessful, the acquisition error information is used to calculate the attitude acquisition correction value from the theoretical value of inter-satellite pointing:

[0048] in and These are the capture error covariance matrices for the current period and the previous period, respectively. Initial values ​​can be taken as... , and These are the pitch acquisition correction coefficients for the current cycle and the previous cycle, respectively, with initial values ​​set to... , and These are the yaw capture correction coefficients for the current cycle and the previous cycle, respectively, with initial values ​​set to... .

[0049] The validity determination of interferometric information in this invention is based on a combination of the theoretical inter-satellite pointing value provided by the ground, the acquisition error information provided by the ranging payload, and the interferometric error information. The specific operation is as follows.

[0050] For valid judgment information , , , , , Perform the calculation:

[0051] If there is Simultaneously satisfy, or If both conditions are met, the interference error information for this period is invalid; otherwise, the interference error information for this period is valid. These are the upper and lower thresholds for judging pitch effectiveness, typically ranging from 20 to 30 urad and 5 to 15 urad, respectively. These are the upper and lower thresholds for judging yaw effectiveness, respectively, and their values ​​are generally 20~30urad and 5~15urad.

[0052] 3. Explanation of Distance Measurement Load Related Modes The ranging payload's scanning mode uses a rotating mirror to control the emitted beam to perform a rapid two-dimensional spatial scan of the uncertain region where the peer satellite is located, until the peer satellite receives the laser beam emitted by the local satellite during the process, thereby correcting the peer satellite's orientation and emitting a return beam to the local satellite along the optical path.

[0053] The coarse-tracking mode of the ranging payload uses a rotating mirror to control the direction of the outgoing beam by two-dimensional rotation based on the acquisition error information of the acquisition sensor, so as to reduce and eliminate the acquisition error and make the outgoing light and the incident light optical path consistent to achieve the interference condition.

[0054] The precision tracking mode of the ranging payload uses a rotating mirror to control the direction of the outgoing beam by two-dimensional rotation based on the interference error information of the interferometer sensor, so as to reduce and eliminate the interference error and make the outgoing light and the incident light optical path consistent.

[0055] For specific methods, please refer to CN119316041B, CN115333605B, CN120750434B and CN119960297A.

[0056] The above description is only the best specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the protection scope of the present invention.

[0057] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for ensuring stable pointing of inter-satellite signals while maintaining narrow beam alignment of ranging payloads, characterized in that... The method involves two satellites equipped with ranging payloads. The ranging payloads are coaxial with the X-axis of the satellite's own system. The ranging payloads are equipped with an acquisition sensor, a rotating mirror, and an interferometer. The acquisition sensor provides a signal indicating successful acquisition of the incident light and information on the acquisition error. The rotating mirror performs a two-dimensional rotation to adjust the direction of the outgoing light so that the outgoing light and the incident light are aligned and interfere. The interferometer provides a signal indicating successful interference and information on the interference error. During satellite flight, an inter-satellite pointing attitude is established, which is the attitude in which the X-axis of the two satellites are aligned with each other and point towards the position of the other satellite. The initial values ​​for attitude acquisition correction, attitude interference correction, and acquisition error correction are set to 0. During flight, the attitude interference correction and acquisition error correction values ​​are updated in real time based on the validity of the signal given by the ranging payload. When both the acquisition success signal and the interference success signal are successful, the attitude interference correction and acquisition error correction values ​​are updated using the interference error signal. When the acquisition success signal is successful and the interference success signal is unsuccessful, the current acquisition error signal is corrected using the latest acquisition error correction value, and the attitude acquisition correction value is updated using the corrected acquisition error signal. Based on the theoretical value of inter-satellite pointing, the attitude measurement value provided by on-board attitude determination, the attitude acquisition or interference correction value, and the effectiveness of the interference error signal, the stable command control of the inter-satellite signal is completed.

2. The method for ensuring stable pointing of inter-satellite signals to guarantee narrow beam alignment of ranging payloads according to claim 1, characterized in that: The attitude interferometry correction values ​​are updated using interferometry error information. These values ​​include pitch and yaw attitude interferometry correction values, specifically: in, , These are the pitch and yaw attitude interference correction values, respectively. and These are the elevation interference correction coefficients for the current cycle and the previous cycle, respectively. and These are the yaw interference correction coefficients for the current cycle and the previous cycle, respectively. For the current star time, Forgetting factor, and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. and These are the covariance matrices of the interference errors for the current period and the previous period, respectively. , , , These are intermediate variables in the calculation process.

3. The method for ensuring stable pointing of inter-satellite signals to guarantee narrow beam alignment of ranging payloads according to claim 1, characterized in that: Acquisition error correction values ​​include pitch acquisition error correction values ​​and yaw acquisition error correction values, and the calculation formulas are as follows: in, and These are the pitch acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the yaw acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the values ​​for capturing pitch error and yaw error, respectively. and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. Correct the filter coefficients to capture the error.

4. The method for ensuring stable pointing of inter-satellite signals to guarantee narrow beam alignment of ranging payloads according to claim 1, characterized in that: The attitude acquisition correction values ​​are updated using the acquisition error signal. These values ​​include pitch and yaw attitude acquisition correction values, and the calculation formula is as follows: in, , These are the pitch and yaw attitude acquisition correction values, respectively. and These are the capture error covariance matrices for the current period and the previous period, respectively. and These are the pitch acquisition correction coefficients for the current cycle and the previous cycle, respectively. and These are the yaw capture correction coefficients for the current cycle and the previous cycle, respectively. For the current star time, Forgetting factor, and These are the values ​​for capturing pitch error and yaw error, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. , These are the latest pitch and yaw acquisition error correction values. , , , These are intermediate variables in the calculation process.

5. A stable inter-satellite signal pointing system for ensuring narrow beam alignment of ranging payloads, characterized in that... This includes the ranging payload, correction module, and attitude control module configured on both satellites. The ranging payload pointing reference is coaxial with the X-axis of the satellite system. The ranging payload is equipped with an acquisition sensor, a rotating mirror, and an interferometer. The acquisition sensor provides a signal indicating successful acquisition of the incident light and information on the acquisition error. The rotating mirror performs a two-dimensional rotation to adjust the direction of the outgoing light so that the outgoing light and the incident light are aligned and interfere with each other. The interferometer provides a signal indicating successful interference and information on the interference error. The attitude control module establishes an inter-satellite pointing attitude during satellite flight, which is the attitude in which the X-axis of the two satellites are aligned with each other and point towards the position of the other satellite. The correction module performs mutual correction of the three based on the status of the successful acquisition signal and the successful interference signal, combined with the theoretical inter-satellite pointing value provided by the ground, the acquisition error information provided by the ranging payload, and the interference error information, and obtains the attitude acquisition or interference correction value, which is then sent to the attitude control module. The attitude control module, based on the status of successful acquisition signal, successful interference signal, and the validity of interference information, and combining the theoretical value of inter-satellite pointing, the attitude measurement value provided by on-board attitude determination, and the attitude acquisition or interference correction value, completes the stable command control of inter-satellite signals.

6. The inter-satellite signal stable pointing system for ensuring narrow beam alignment of ranging payload according to claim 5, characterized in that: The correction module is implemented in the following manner: The initial values ​​for attitude capture correction and attitude interference correction are set to 0; the attitude capture correction and attitude interference correction values ​​are updated based on the real-time received ranging load information. When both the successful acquisition signal and the successful interference signal are successful, the inter-satellite pointing theoretical value is corrected using the interference error information, and the attitude interference correction value is calculated; at the same time, the acquisition error information is corrected using the interference error information to obtain the acquisition error correction value. When the acquisition success signal is successful but the interference success signal is unsuccessful, the acquisition error information is used to correct the theoretical value of inter-satellite pointing, and the attitude acquisition correction value is obtained.

7. The inter-satellite signal stable pointing system for ensuring narrow beam alignment of ranging payload according to claim 6, characterized in that: Using interferometric error information, attitude interferometric correction values ​​are calculated for the theoretical inter-satellite pointing values: in, , These are the pitch and yaw attitude interference correction values, respectively. and These are the elevation interference correction coefficients for the current cycle and the previous cycle, respectively. and These are the yaw interference correction coefficients for the current cycle and the previous cycle, respectively. For the current star time, Forgetting factor, and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. and These are the covariance matrices of the interference errors for the current period and the previous period, respectively. , , , These are intermediate variables in the calculation process; The formula for calculating the capture error correction value is as follows: in, and These are the pitch acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the yaw acquisition error correction values ​​for the current cycle and the previous cycle, respectively, with an initial value of 0. and These are the values ​​for capturing pitch error and yaw error, respectively. and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. Correct the filter coefficients to capture the error.

8. The inter-satellite signal stable pointing system for ensuring narrow beam alignment of ranging payload according to claim 6, characterized in that: The attitude acquisition correction value is calculated based on the theoretical value of inter-satellite pointing using the acquisition error information: in, , These are the pitch and yaw attitude acquisition correction values, respectively. and These are the capture error covariance matrices for the current period and the previous period, respectively. and These are the pitch acquisition correction coefficients for the current cycle and the previous cycle, respectively. and These are the yaw capture correction coefficients for the current cycle and the previous cycle, respectively. For the current star time, Forgetting factor, and These are the values ​​for capturing pitch error and yaw error, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. , These are the latest pitch and yaw acquisition error correction values. , , , These are intermediate variables in the calculation process.

9. The inter-satellite signal stable pointing system for ensuring narrow beam alignment of ranging payload according to claim 5, characterized in that: Based on the theoretical inter-satellite pointing values ​​provided by the ground, the acquisition error information provided by the ranging payload, and the interferometric error information, the validity of the interferometric error information is determined by combining these three factors. The specific operation is as follows: For valid judgment information , , , , , Perform the calculation: If there is Simultaneously satisfy, or If both conditions are met, the interference error information for this period is invalid; otherwise, the interference error information for this period is valid. These are the upper and lower thresholds for judging pitch effectiveness, with values ​​of 20~30urad and 5~15urad, respectively. These are the upper and lower thresholds for judging yaw effectiveness, with values ​​of 20~30urad and 5~15urad, respectively. and These are the interferometric pitch error values ​​and the interferometric yaw error values, respectively. These are pitch attitude measurement values. This is the yaw attitude measurement value. , These are the theoretical values ​​for pitch and yaw pointing, respectively. , These are the latest pitch and yaw acquisition error correction values. , These are the pitch and yaw attitude interference correction values, respectively.

10. The inter-satellite signal stable pointing system for ensuring narrow beam alignment of ranging payload according to claim 5, characterized in that: The acquisition error information is the pointing deviation information provided by the acquisition sensor, which includes two parts: acquisition pitch error and acquisition yaw error. Theoretically, the magnitude and direction of the attitude pitch control error and yaw control error are the same as those when the on-board target pointing angle calculation deviation and star-sensor attitude determination deviation are not considered. The interference error information is the pointing deviation information provided by the interference sensor, which includes two parts: interference pitch error and interference yaw error. Theoretically, the magnitude and direction of the attitude pitch control error and yaw control error are the same as those when the on-board target pointing angle calculation deviation and star-sensor attitude determination deviation are not considered.

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