Satellite laser communication receiving point coarse tracking method and system

Abstract

The invention discloses a satellite laser communication receiving point coarse tracking method and system, and belongs to the technical field of laser communication. Through an optimized APT system, a satellite laser signal is coarsely tracked, the distance from a light spot to the center of a coarse tracking detector is obtained, the tracking error of a focusing lens at each position point is determined according to the distance from the light spot to the center of the coarse tracking detector, and when the APT system detects that the tracking error of the focusing lens at a certain position point exceeds an error threshold value, the focusing lens is started. Determining that the satellite laser signal has strong disturbance at the position point, linearly moving the focusing lens along the direction of the optical axis, and acquiring the positions of the focusing lens and the light spot imaged by the coarse tracking detector when the strong disturbance occurs; by dynamically adjusting the position of the focusing lens, the position of the focusing lens when the light spot does not deviate from the center of the detector is used as the optimal position, and coarse tracking is continued. The method can effectively reduce the link interruption risk caused by the fact that the light spot deviates from the center of the detector.

Description

Technical Field

[0001] This invention relates to the field of laser communication technology, and more specifically to a coarse tracking method and system for satellite laser communication receivers. Background Technology

[0002] The rapid development of satellite laser communication technology has not only increased data transmission rates, but the widespread adoption of miniaturized low Earth orbit satellites has also increased the risk of attitude drift and structural vibration, leading to a decline in signal reception quality and system stability.

[0003] Compared to traditional radio frequency (RF) communication, satellite laser communication offers significant advantages, including higher data transmission rates, greater capacity, enhanced link security, smaller size, lighter weight, and lower power consumption. Due to the small beam divergence angle and long communication distance, establishing and maintaining a stable optical link requires a fast and high-precision acquisition, pointing, and tracking (APT) system. In inter-satellite links, the APT system process comprises three phases: initial pointing based on orbital data, scanning and acquiring the target beam, and tracking to stabilize the beam at the center of the field of view.

[0004] The APT (Action Tracking) system in an inter-satellite laser communication system is used to establish and maintain laser communication links between satellites. A typical APT tracking system consists of two subsystems: coarse tracking and fine tracking, which are responsible for large-scale scanning acquisition and high-precision locking, respectively, during communication. The stability of the coarse tracking system directly affects the system's link-keeping capability under large disturbances. To improve the stability of the APT system under dynamic interference, existing methods mainly employ high-frame-rate detectors, fast-response actuators, dual-axis control structures, and advanced vibration suppression algorithms.

[0005] However, due to the limited field of view of the coarse tracking detector in the existing APT system, when subjected to strong external disturbances, the light spot will quickly deviate from the center of the detector, resulting in poor stability of the APT system, which may cause link interruption and thus affect communication quality. Summary of the Invention

[0006] To address the problems existing in the above-mentioned fields, this invention proposes a coarse tracking method and system for satellite laser communication receivers. When the APT system detects that the tracking error between the focusing lens and the coarse tracking detector at a newly added location point exceeds the error threshold, it determines that the satellite laser signal has experienced a strong disturbance at that location point. The focusing lens is then moved linearly along the optical axis, and the optimal position is determined by dynamically adjusting the position of the focusing lens. Coarse tracking continues, improving the continuous tracking capability of coarse tracking under sudden disturbances and effectively reducing the risk of link interruption caused by the light spot deviating from the detector center.

[0007] To address the aforementioned technical problems, this invention discloses a coarse tracking method for satellite laser communication receivers, comprising the following steps: Acquire satellite laser signals; An optimized APT system is used to coarsely track satellite laser signals and obtain the distance from the light spot to the center of the coarse tracking detector. The optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Based on the distance from the light spot to the center of the coarse tracking detector, the tracking error of the focusing lens at each position point is determined. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it is determined that the satellite laser signal has a strong disturbance at that position point. The focusing lens is then moved linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. By dynamically adjusting the position of the focusing lens, the optimal position is determined when the light spot does not deviate from the center of the detector, and coarse tracking is then performed.

[0008] Preferably, acquiring the positions of the light spots imaged by the focusing lens and the coarse tracking detector when a strong disturbance occurs specifically includes: Two new position points are added along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Position point A corresponds to the normal state, and position points B1-B1 are also added. n This corresponds to a disturbance state; At position point A, the focusing lens focuses the beam onto the center of the coarse tracking detector, and the focusing lens and the coarse tracking detector maintain a fixed focal length; A fixed distance between the focusing lens and the center of the coarse tracking detector is used as the error threshold; When the APT system detects that the tracking error of the focusing lens at a certain position point Bi in B1-Bn exceeds the error threshold, it determines that a strong disturbance has occurred, and moves the focusing lens linearly along the optical axis within the position point B1-Bn. By gradually expanding or shrinking the size of the light spot, the position of the light spot is determined.

[0009] Preferably, the linear movement of the focusing lens along the optical axis is as follows: By setting up a control circuit in the APT system that matches the electric slide rail, the left and right movement of the electric slide rail can be controlled by the control circuit. The focusing lens is moved left and right on the electric slide rail by the control circuit to determine the focusing lens position between B1 and B. n The position in the middle.

[0010] Preferably, the acquisition of the spot size of the focusing lens and the coarse tracking detector when a strong disturbance occurs is achieved by adjusting the angle between the focusing lens and the coarse tracking detector using a rotating device in the APT system, thereby enabling the focusing lens and the coarse tracking detector to form an image, and then acquiring the position of the spot through the image.

[0011] Preferably, the rotating device is a two-dimensional turntable fixed to the base of the focusing lens. The two-dimensional turntable is electrically connected to the electric slide rail. The rotation of the two-dimensional turntable is controlled by the control circuit to adjust the angle between the focusing lens and the coarse tracking detector.

[0012] Preferably, it also includes a coarse tracking system for satellite laser communication receivers, comprising: The signal acquisition module is used to acquire satellite laser signals; The coarse tracking module is used to track satellite laser signals using an optimized APT system to obtain the distance from the light spot to the center of the coarse tracking detector; wherein, the optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens; The adaptive focusing lens position adjustment module is used to determine the tracking error of the focusing lens at each position point based on the distance from the light spot to the center of the coarse tracking detector. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it determines that the satellite laser signal has a strong disturbance at that position point, and moves the focusing lens linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. The coarse tracking dynamic adjustment module is used to dynamically adjust the position of the focusing lens to determine the optimal position of the focusing lens when the light spot does not deviate from the center of the detector, and then continue coarse tracking.

[0013] Preferably, the device further includes a computer apparatus, the computer apparatus comprising a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the following steps: Acquire satellite laser signals; An optimized APT system is used to coarsely track satellite laser signals and obtain the distance from the light spot to the center of the coarse tracking detector. The optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Based on the distance from the light spot to the center of the coarse tracking detector, the tracking error of the focusing lens at each position point is determined. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it is determined that the satellite laser signal has a strong disturbance at that position point. The focusing lens is then moved linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. By dynamically adjusting the position of the focusing lens, the optimal position is determined when the light spot does not deviate from the center of the detector, and coarse tracking is then performed.

[0014] Preferably, the system further includes a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the following steps: Acquire satellite laser signals; An optimized APT system is used to coarsely track satellite laser signals and obtain the distance from the light spot to the center of the coarse tracking detector. The optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Based on the distance from the light spot to the center of the coarse tracking detector, the tracking error of the focusing lens at each position point is determined. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it is determined that the satellite laser signal has a strong disturbance at that position point. The focusing lens is then moved linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. By dynamically adjusting the position of the focusing lens, the optimal position is determined when the light spot does not deviate from the center of the detector, and coarse tracking is then performed.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The proposed coarse tracking method for satellite laser communication receivers in this invention forms an optimized APT system by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector. This optimized APT system avoids the uncertainties and mechanical vibrations caused by continuous focusing, thus enhancing reliability. When the APT system detects that the tracking error between the focusing lens and the coarse tracking detector at a certain position point exceeds the error threshold, it determines that the satellite laser signal has a strong disturbance at that position point. The focusing lens is then moved linearly along the optical axis. At this time, the position of the light spot received by the coarse tracking detector is gradually expanded or reduced by the size of the light spot, allowing the light spot to cover a larger area. The position of the focusing lens when the light spot does not deviate from the detector center is taken as the optimal position, and coarse tracking continues. This increases the probability of residual energy entering the field of view, extends the tracking duration, and provides a compensation window for the coarse tracking mechanism. It can effectively reduce the risk of link interruption caused by the light spot deviating from the detector center, improving the robustness and stability of the system. Attached Figure Description

[0016] Figure 1 This is a flowchart of the coarse tracking method for satellite laser communication receiver points proposed in this invention; Figure 2 A conventional APT system structure diagram provided in the embodiments of the present invention; Figure 3 This is a schematic diagram of the anti-interference principle corresponding to the coarse tracking method provided by the present invention; Figure 4 The simulation tracking results of the traditional method and the coarse tracking method proposed in this invention are provided for embodiments of the present invention under the same interference conditions. Figure 5 A comparison of the link interruption frequency between the conventional method provided in the embodiments of the present invention and the coarse tracking method proposed in the present invention. Detailed Implementation

[0017] The following will refer to the appendices in the embodiments of the present invention. Figures 1-5 The technical solutions in the embodiments of the present invention will be clearly and completely described. It should be understood that the terminology used in the present invention is only for describing particular implementation methods and is not intended to limit the present invention.

[0018] Example like Figure 1 As shown, this invention proposes a coarse tracking method for satellite laser communication receiver points, comprising the following steps: Acquire satellite laser signals; The optimized APT system is used to coarsely track the satellite laser signal and obtain the distance from the light spot to the center of the coarse tracking detector. The optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Based on the distance from the light spot to the center of the coarse tracking detector, the tracking error of the focusing lens at each position point is determined. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it is determined that the satellite laser signal has a strong disturbance at that position point. The focusing lens is then moved linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. By dynamically adjusting the position of the focusing lens, the optimal position is determined when the light spot does not deviate from the center of the detector, and coarse tracking is then performed.

[0019] Specifically, obtaining the positions of the light spots imaged by the focusing lens and the coarse tracking detector when a strong disturbance occurs includes: Two new position points are added along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Position point A corresponds to the normal state, and position points B1-B1 are also added. n This corresponds to a disturbance state; At position point A, the focusing lens focuses the beam onto the center of the coarse tracking detector, and the focusing lens and the coarse tracking detector maintain a fixed focal length; A fixed distance between the focusing lens and the center of the coarse tracking detector is used as the error threshold; When the APT system detects that the focusing lens is at B1-B n A certain location B i When the tracking error exceeds the error threshold, it is determined to be a strong disturbance, and the focusing lens is moved along the optical axis at position point B1-B. n The internal linear movement determines the position of the light spot by gradually increasing or decreasing the size of the light spot.

[0020] The focusing lens is moved linearly along the optical axis as follows: By setting up a control circuit in the APT system that matches the electric slide rail, the left and right movement of the electric slide rail can be controlled by the control circuit. The focusing lens is moved left and right on the electric slide rail by the control circuit to determine the focusing lens position between B1 and B. n The position in the middle.

[0021] The size of the light spot imaged by the focusing lens and the coarse tracking detector when a strong disturbance occurs is obtained by rotating a device in the APT system. The angle between the focusing lens and the coarse tracking detector is adjusted by rotating the device to achieve imaging between the focusing lens and the coarse tracking detector, and the position of the light spot is obtained through imaging.

[0022] The rotating device is a two-dimensional turntable fixed on the base of the focusing lens. The two-dimensional turntable is electrically connected to the electric slide rail. The rotation of the two-dimensional turntable is controlled by the control circuit to adjust the angle between the focusing lens and the coarse tracking detector.

[0023] This invention also proposes a coarse tracking system for satellite laser communication receivers, comprising: The signal acquisition module is used to acquire satellite laser signals; The coarse tracking module is used to track satellite laser signals using an optimized APT system to obtain the distance from the laser spot to the center of the coarse tracking detector. The optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. The adaptive focusing lens position adjustment module is used to determine the tracking error of the focusing lens at each position point based on the distance from the light spot to the center of the coarse tracking detector. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it determines that the satellite laser signal has a strong disturbance at that position point, and moves the focusing lens linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. The coarse tracking dynamic adjustment module is used to dynamically adjust the position of the focusing lens to determine the optimal position of the focusing lens when the light spot does not deviate from the center of the detector, and then continue coarse tracking.

[0024] The coarse tracking method proposed in this invention improves the continuous tracking capability under sudden disturbances by adaptively adjusting the position of the focusing lens, effectively reducing the risk of link interruption caused by the spot deviating from the detector center, and improving the robustness and stability of the system.

[0025] like Figure 2 As shown in Figure (a), the traditional APT system structure includes an acquisition control unit (capture control unit) for initial alignment and signal search; a coarse tracking servo unit that achieves large-angle rotation via a two-dimensional turntable; a fine tracking servo unit that performs high-frequency adjustment of small angles via a fast reflector; a beam emission unit that emits local laser; a lead alignment unit for line-of-sight offset control; and an optical transceiver assembly including an optical receiving path and a transmitting path.

[0026] The coarse tracking servo unit mainly consists of a coarse pointing mechanism, a controller, and a detector. Its main function is to dynamically track the target and ensure that the target remains stably within the field of view of the tracking sensor.

[0027] The optical structure mainly includes a Cassegrain telescope, collimating beam expander, beam splitter, filter, focusing lens, optical detector, and laser. The control mechanism includes a two-dimensional coarse tracking turntable, a fine tracking fast-reflecting mirror, and control circuitry.

[0028] The satellite laser signal emitted by the remote satellite is received by the telescope system at this end; the beam is guided by collimator, expander and beam splitter, and part of the signal enters the coarse tracking path; after filtering and focusing, it is projected onto the coarse tracking detector; the system adjusts the attitude of the light spot by turning the turntable according to the position of the light spot on the detector, so that the light spot is close to the center of the coarse tracking detector; after the light spot is located in the central area of ​​the coarse tracking detector, the signal can be transmitted into the field of view of the fine tracking detector; the fast-reflecting mirror is fine-tuned according to the signal from the fine detector to achieve high-precision tracking.

[0029] This invention proposes an adaptive spot size adjustment mechanism based on the traditional APT system. This mechanism improves the tracking robustness of the system by optimizing the coarse tracking structure, such as... Figure 2 Figure (a) shows the traditional coarse tracking process. The main optical path laser is redirected by a beam splitter, passes through a filter and a focusing lens, and arrives at the coarse tracking detector. This invention improves the structure... Figure 2 Figure (b) shows the focusing lens mounted on an electric slide rail (illustrated by a rectangle below a narrow circle in the figure) to adjust the position of the focusing lens.

[0030] This invention proposes an adaptive focusing lens position adjustment mechanism based on the traditional APT system. This mechanism improves the tracking robustness of the APT system through structural optimization, as detailed below: like Figure 3 As shown, the improved structure is located in the coarse tracking optical path, that is, between the traditional "focusing lens and coarse tracking detector", a variable adjustment module is added. The variable adjustment module includes: a set of motorized slide rails, a movable focusing lens, and a control circuit that matches the motorized slide rails and the focusing lens.

[0031] The focusing lens is mounted on an electric slide rail and moves linearly along the optical axis under control commands. By changing the distance between the focusing lens and the coarse tracking detector, the imaging position of the light spot is changed, thereby realizing the dynamic adjustment of the diameter of the light spot received on the coarse tracking detector.

[0032] This invention optimizes the coarse tracking mechanism in traditional APT systems by introducing an adaptive focusing lens position adjustment mechanism, thereby improving its tracking robustness under strong interference conditions. The proposed coarse tracking method dynamically adjusts the position of the focusing lens according to the current interference level, thus adjusting the position of the beam spot received by the detector, thereby reducing the risk of tracking interruption due to field-of-view deviation.

[0033] The coarse tracking method proposed in this invention aims to make the distance between the focusing lens and the coarse tracking detector adjustable, for example, by adding a fast, high-precision linear platform between the lens and the camera. Figure 3As shown. The improved coarse tracking design of this invention reduces the impact of uncertainties caused by mechanical motion on stable tracking by setting two fixed working positions in the APT system, wherein:

[0034] Position A maintains a fixed focal length between the focusing lens and the detector, resulting in a concentrated light spot that facilitates high-precision position information extraction and maintains normal tracking. Under normal circumstances, the focusing lens focuses the light beam onto the center of the coarse-tracking detector, achieving high-precision tracking.

[0035] Position B is where, when the system detects a tracking error exceeding the error threshold, a strong disturbance is identified. The lens quickly moves to position B, at which point the size of the light spot received by the detector increases, covering a wider area, increasing the probability of residual energy entering the field of view, and extending the tracking duration, thus providing a compensation window for the coarse tracking mechanism. Under severe interference, the focusing lens moves to enlarge the beam spot and prolong its residence time within the FOV of the coarse tracking detector.

[0036] By using only two fixed working points in the design, the uncertainty and mechanical vibration caused by continuous focusing are avoided, thus enhancing reliability.

[0037] The improved structure described above can enhance the continuous tracking capability of coarse tracking under sudden disturbances without changing the overall structure and control mechanism of the APT system. It effectively reduces the risk of link interruption caused by the spot deviating from the detector center, thus improving system robustness and stability. Compared to traditional structures, the method proposed in this invention exhibits higher link retention and fault tolerance under strong disturbance simulation environments, demonstrating significant engineering application value.

[0038] Although the enlarged spot reduces the center intensity, the edge intensity is still higher than the preset minimum error of the coarse tracking detector, i.e., the error threshold. In traditional coarse tracking systems, when external interference exceeds the compensation range of the tracking algorithm, the spot may move out of the coarse tracking detector's field of view, leading to tracking failure and link interruption, forcing the system to re-enter the scanning and acquisition phase, wasting valuable communication time. However, with the improved coarse tracking method proposed in this invention, even if the spot center deviates from the field of view, part of the spot can still be captured by the camera, allowing the system to continue tracking and significantly reducing the risk of interruption.

[0039] Simulation Analysis To evaluate the effectiveness of the method proposed in this invention under complex conditions, a simulation model was first developed based on the structure and working principle of the conventional and the improved APT system proposed in this invention.

[0040] The orbital data is derived from publicly available two-line orbital data (TLE) files, and the initial pointing error is modeled as independent standard Gaussian variables on the azimuth and altitude axes.

[0041] The interference factors considered included platform micro-vibrations, coarse tracking coupling, and satellite attitude drift, while also taking into account extreme cases of drift instability. Micro-vibrations were simulated using Gaussian white noise processed by a low-pass filter to replicate the power spectral density model of the ESA Olympus satellite. Attitude drift exhibited a slow, sinusoidal trend, but the drift velocity could reach up to 50 microradians / second, potentially leading to a deviation of approximately 1000 microradians under anomalous conditions. The system used a beam divergence angle (half-angle) of 100 microradians and a communication range of 6000 kilometers. A stepped rectangular helical scan was employed with a time interval of 0.07 seconds.

[0042] In the coarse tracking phase, this embodiment employs a cascaded proportional-integral-derivative (PID) controller; while in the fine tracking phase, model reference adaptive control and an adaptive strong tracking Kalman filter algorithm are used. This embodiment compares and analyzes the traditional methods in APT system simulation with the improved coarse tracking method proposed in this invention. Each simulation lasts 300 seconds, covering the typical duration of the low Earth orbit (LEO) laser communication window (e.g., in Starlink-like scenarios).

[0043] like Figure 4 As shown, a set of typical tracking data from a simulation run demonstrates the performance difference between the traditional coarse tracking structure and the improved coarse tracking structure proposed in this invention. The operating status of the coarse tracking system can be observed based on the tracking status flags and tracking error values. Initially, the pointing error was approximately 1000 microradians, and due to external interference, the tracking error fluctuated continuously. Through continuous adjustment and compensation by the adaptive focusing lens position adjustment module and the coarse tracking module proposed in this invention, the error gradually decreased to a low level within 10 seconds, and the light spot was effectively guided to the center of the field of view.

[0044] Within a 10-20 second time interval, the system maintained relatively stable tracking. Around the 21st second, a large satellite attitude drift disturbance was introduced, causing the tracking error in the traditional structure to increase rapidly, approaching the detection limit around the 23rd second. For traditional methods, the tracking algorithm could not compensate for the disturbance in time, causing the tracking flag to change from 1 to 0, resulting in a link interruption and entering a reacquisition phase. Figure 4 As shown in Figure (a).

[0045] In contrast, the method proposed in this embodiment retains some signal energy within the detector's field of view by adaptively increasing the spot size. This allows the coarse tracking method to successfully compensate for abrupt interference, thus maintaining uninterrupted tracking throughout the simulation process. Figure 4 As shown in Figure (b).

[0046] To further verify the improved robustness under different interference scenarios, Monte Carlo simulations were also performed in this embodiment.

[0047] By calculating the number of link interruptions within a fixed time range, severe interference was intentionally introduced to demonstrate the improved effect of the proposed method. To reduce the impact of random fluctuations, multiple sets of comparative experiments were conducted, with each dataset reflecting the results of 100 independent simulations.

[0048] like Figure 5 As shown, the comparison between the traditional method and the coarse tracking method proposed in this invention in terms of link interruption frequency is illustrated. A total of five sets of experiments were conducted, with each test set consisting of 100 Monte Carlo simulations (each lasting 300 seconds).

[0049] The coarse tracking method provided in this embodiment experienced an average of 69.04 link interruptions in a 300-second simulation, while the improved coarse tracking method of this invention reduced this number to 39.90, a reduction of 42.2%. This significant reduction indicates that the improved design of this invention has stronger robustness in the face of sudden interference.

[0050] Simulation results show that the proposed scheme effectively reduces the risk of tracking interruption under complex spatial interference, avoids frequent link reconstruction, and significantly enhances the robustness of the APT system.

[0051] Given the high stability requirements of LEO satellite communication links, this improvement can significantly reduce the possibility of communication errors caused by sudden interruptions.

[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0053] Furthermore, unless otherwise stated, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. All references to this specification are incorporated by way of citation to disclose and describe methods relating to those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

Claims

1. A method for coarse tracking of a satellite laser communication receiver point, characterized in that, Includes the following steps: Acquire satellite laser signals; An optimized APT system is used to coarsely track satellite laser signals and obtain the distance from the light spot to the center of the coarse tracking detector. The optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Based on the distance from the light spot to the center of the coarse tracking detector, the tracking error of the focusing lens at each position point is determined. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it is determined that the satellite laser signal has a strong disturbance at that position point. The focusing lens is then moved linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. By dynamically adjusting the position of the focusing lens, the optimal position is determined when the light spot does not deviate from the center of the detector, and coarse tracking is then performed.

2. The coarse tracking method for satellite laser communication receiver points according to claim 1, characterized in that, The acquisition of the positions of the light spots imaged by the focusing lens and the coarse tracking detector when a strong disturbance occurs specifically includes: Two new position points are added along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Position point A corresponds to the normal state, and position points B1-B1 are also added. n This corresponds to a disturbance state; At position point A, the focusing lens focuses the beam onto the center of the coarse tracking detector, and the focusing lens and the coarse tracking detector maintain a fixed focal length; A fixed distance between the focusing lens and the center of the coarse tracking detector is used as the error threshold; When the APT system detects that the focusing lens is at B1-B n A certain location B i When the tracking error exceeds the error threshold, it is determined to be a strong disturbance, and the focusing lens is moved along the optical axis at position point B1-B. n The internal linear movement determines the position of the light spot by gradually increasing or decreasing the size of the light spot.

3. The coarse tracking method for satellite laser communication receiver points according to claim 2, characterized in that, The linear movement of the focusing lens along the optical axis is as follows: By setting up a control circuit in the APT system that matches the electric slide rail, the left and right movement of the electric slide rail can be controlled by the control circuit. The focusing lens is moved left and right on the electric slide rail by the control circuit to determine the focusing lens position between B1 and B. n The position in the middle.

4. The coarse tracking method for satellite laser communication receiver points according to claim 3, characterized in that, The position of the light spot formed by the focusing lens and the coarse tracking detector when a strong disturbance occurs is obtained by adjusting the angle between the focusing lens and the coarse tracking detector using a rotating device in the APT system, thereby achieving imaging between the focusing lens and the coarse tracking detector, and obtaining the position of the light spot through imaging.

5. The coarse tracking method for satellite laser communication receiver points according to claim 4, characterized in that, The rotating device is a two-dimensional turntable fixed to the base of the focusing lens. The two-dimensional turntable is electrically connected to the electric slide rail. The rotation of the two-dimensional turntable is controlled by the control circuit to adjust the angle between the focusing lens and the coarse tracking detector.

6. A coarse tracking system for satellite laser communication receivers, characterized in that, include: The signal acquisition module is used to acquire satellite laser signals; The coarse tracking module is used to track satellite laser signals using an optimized APT system to obtain the distance from the light spot to the center of the coarse tracking detector; wherein, the optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens; The adaptive focusing lens position adjustment module is used to determine the tracking error of the focusing lens at each position point based on the distance from the light spot to the center of the coarse tracking detector. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it determines that the satellite laser signal has a strong disturbance at that position point, and moves the focusing lens linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. The coarse tracking dynamic adjustment module is used to dynamically adjust the position of the focusing lens to determine the optimal position of the focusing lens when the light spot does not deviate from the center of the detector, and then continue coarse tracking.

7. A computer device, characterized in that, The computer device includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the following steps: Acquire satellite laser signals; An optimized APT system is used to coarsely track satellite laser signals and obtain the distance from the light spot to the center of the coarse tracking detector. The optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Based on the distance from the light spot to the center of the coarse tracking detector, the tracking error of the focusing lens at each position point is determined. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it is determined that the satellite laser signal has a strong disturbance at that position point. The focusing lens is then moved linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. By dynamically adjusting the position of the focusing lens, the optimal position is determined when the light spot does not deviate from the center of the detector, and coarse tracking is then performed.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to perform the following steps: Acquire satellite laser signals; An optimized APT system is used to coarsely track satellite laser signals and obtain the distance from the light spot to the center of the coarse tracking detector. The optimized APT system is achieved by adding multiple new position points along the optical axis between the focusing lens and the coarse tracking detector to fix the focusing lens. Based on the distance from the light spot to the center of the coarse tracking detector, the tracking error of the focusing lens at each position point is determined. When the APT system detects that the tracking error of the focusing lens at a certain position point exceeds the error threshold, it is determined that the satellite laser signal has a strong disturbance at that position point. The focusing lens is then moved linearly along the optical axis to obtain the position of the light spot imaged by the focusing lens and the coarse tracking detector when the strong disturbance occurs. By dynamically adjusting the position of the focusing lens, the optimal position is determined when the light spot does not deviate from the center of the detector, and coarse tracking is then performed.

Images