Satellite-ground laser communication broken link reconstruction method and device based on downlink light spot miss distance

Abstract

The invention provides a satellite-ground laser communication broken link reconstruction method and device based on downlink light spot miss distance, and the method comprises the steps: controlling a ground station to start a coarse tracking closed-loop process when a downlink signal light spot appears in a coarse tracking view field; determining the light spot miss distance of the downlink signal light spot, correcting the servo direction based on the light spot miss distance, and recording the light spot miss distance; when the downlink signal light spot in the coarse tracking view field disappears, closing a coarse tracking closed loop; on the basis of the recorded light spot miss distance, predicting the predicted correction of servo pointing at each moment after the downlink signal light spot disappears; based on the predicted correction amount of each moment, correcting the servo direction to obtain a predicted correction direction of each moment of the servo; when the downlink signal light spot appears in the coarse tracking view field, searching a prediction correction direction corresponding to the moment when the downlink signal light spot appears; and on the basis of the corresponding prediction correction direction, a coarse tracking closed loop is opened to reconstruct the satellite-ground laser communication link, so that rapid link reconstruction is realized, and the relink efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a method and device for reconstructing a satellite-to-ground laser communication link break based on a downlink light spot miss amount. Background Art

[0002] During satellite-to-ground laser communication, situations that may cause link interruption may occur, such as overhead blind spot avoidance, transit avoidance, cloud cover, etc. The above interruption events require the ground station to be able to quickly recapture satellite signals after link interruption to restore the communication link.

[0003] In the prior art, when the above link is interrupted, the ground station needs to realign the satellite, but due to the deviation of trajectory prediction, the satellite may have deviated from the coverage of the ground station's uplink beacon light, which increases the difficulty of re-establishing the communication link. In addition, the existing coarse tracking closed-loop system cannot effectively predict and correct the servo pointing after the light spot is lost, resulting in the inability to quickly recapture the downlink signal light spot and quickly rebuild the link. Summary of the invention

[0004] The present invention provides a method and device for reconstructing a satellite-to-ground laser communication link break based on the downlink spot miss amount, so as to solve the technical problem in the prior art that the satellite-to-ground laser communication link cannot be quickly reconstructed after the link is broken.

[0005] On the one hand, the present invention provides a method for reconstructing a satellite-to-ground laser communication link break based on the downlink spot miss amount, comprising: When a downlink signal spot appears in the coarse tracking field of view, the ground station is controlled to start the coarse tracking closed-loop process to establish a satellite-to-ground laser communication link; Determine the spot miss amount of the downlink signal spot, correct the servo pointing based on the spot miss amount, and record the spot miss amount; When the downlink signal spot in the coarse tracking field of view disappears, closing the coarse tracking closed loop to disconnect the satellite-to-ground laser communication link; Based on the recorded spot miss amount, predict the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears; Based on the predicted correction amount at each moment, the servo orientation is corrected to obtain the predicted corrected orientation of the servo at each moment; When a downlink signal light spot appears in the coarse tracking field of view, searching for the predicted correction direction corresponding to the moment when the downlink signal light spot appears; Based on the corresponding predicted and corrected pointing, a coarse tracking loop is started to reconstruct the satellite-to-ground laser communication link.

[0006] According to a method for reconstructing a satellite-to-ground laser communication link break based on the downlink spot miss amount provided by the present invention, the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears is predicted based on the recorded spot miss amount, including: Obtaining a preset initial parameter vector, and constructing a nonlinear variation function of the initial parameter vector in the time dimension; Based on the nonlinear variation function, determining the partial derivative of the initial parameter vector; Constructing a Jacobian matrix based on partial derivatives of the initial parameter vector; Based on the Jacobian matrix, the initial parameter vector is iteratively updated to obtain a parameter update result; Determine whether the parameter update result meets the preset iteration stop condition; If so, stop iterating and updating the initial parameter vector, and use the parameter update result after stopping the iterative update to fit the nonlinear change function; Based on the fitted nonlinear variation function, the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears is obtained.

[0007] According to a method for reconstructing a satellite-to-ground laser communication link break based on the downlink spot miss amount provided by the present invention, the nonlinear variation function is shown in the following formula: ;in, For time, is the initial parameter vector, in degrees; The Jacobian matrix is ​​shown in the following formula: ;in, is the element in the i-th row and j-th column of the Jacobian matrix J; , n is the number of samples, m is the number of parameters; i is the index of the number of samples, i is from 1 to n; j is the index of the number of parameters, j is from 1 to m.

[0008] According to a method for reconstructing a broken link in satellite-to-ground laser communication based on the downlink spot miss amount provided by the present invention, the iterative updating of the initial parameter vector to obtain the parameter update result includes: The initial parameter vector is iteratively updated using Loewenberg-Marquardt to obtain the parameter update result.

[0009] According to a method for reconstructing a broken link in satellite-to-ground laser communication based on the downlink spot miss amount provided by the present invention, the initial parameter vector is iteratively updated using Loewenberg-Marquardt to obtain a parameter update result, including: ; Where k is the number of iterations; is the initial parameter vector for the kth iteration; is the initial parameter vector for the k+1th iteration; is the update amount of the initial parameter vector in the kth iteration; in, ;in, is the adjustment factor; I is the unit matrix; is the residual vector; in, ; is the spot off-target amount.

[0010] According to a method for reconstructing a broken link in satellite-to-ground laser communication based on the downlink spot miss amount provided by the present invention, the method of fitting a nonlinear change function using the parameter update result after stopping the iterative update comprises: ;in, is the spot off-target amount at time t; The parameter update result after stopping the iteration update.

[0011] According to a satellite-to-ground laser communication broken link reconstruction method based on downlink spot miss amount provided by the present invention, the preset iteration stop condition includes: The residual sum of squares of the residual vector converges; or The spot off-target amount is less than the preset convergence accuracy.

[0012] According to a method for reconstructing a satellite-to-ground laser communication link break based on a downlink spot miss amount provided by the present invention, the servo pointing correction based on the spot miss amount includes: Based on the spot miss amount, PID is used to correct the servo pointing.

[0013] On the other hand, the present invention also provides a satellite-to-ground laser communication link reconstruction device based on the downlink spot miss amount, comprising: The coarse tracking module controls the ground station to start the coarse tracking closed-loop process to establish a satellite-to-ground laser communication link when a downlink signal spot appears in the coarse tracking field of view; A light spot miss amount module is used to determine the light spot miss amount of the downlink signal light spot, correct the servo pointing based on the light spot miss amount, and record the light spot miss amount; A closing module, when the downlink signal spot in the coarse tracking field of view disappears, closes the coarse tracking closed loop to disconnect the satellite-to-ground laser communication link; A prediction module, based on the recorded spot miss amount, predicts the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears; A correction module, which corrects the servo orientation based on the predicted correction amount at each moment to obtain the predicted corrected orientation of the servo at each moment; A search module, when a downlink signal light spot appears in the coarse tracking field of view, searches for the predicted correction direction corresponding to the moment when the downlink signal light spot appears; The reconstruction module, based on the corresponding predicted correction pointing, starts the coarse tracking closed loop to reconstruct the satellite-to-ground laser communication link.

[0014] On the other hand, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements any of the above-mentioned methods for reconstructing a broken link in satellite-to-ground laser communication based on the downlink light spot off-target amount.

[0015] The present invention provides a method and device for reconstructing a broken link in satellite-to-ground laser communication based on the off-target amount of a downlink light spot. When a downlink signal light spot in a coarse tracking field of view disappears, a coarse tracking closed loop is closed to disconnect the satellite-to-ground laser communication link; based on the recorded off-target amount of the light spot, a predicted correction amount of the servo pointing at each moment after the disappearance of the downlink signal light spot is predicted; based on the predicted correction amount at each moment, the servo pointing is corrected to obtain the predicted corrected pointing of the servo at each moment; when a downlink signal light spot appears in the coarse tracking field of view, the predicted corrected pointing corresponding to the moment when the downlink signal light spot appears is searched; based on the corresponding predicted corrected pointing, a coarse tracking closed loop is opened to reconstruct the satellite-to-ground laser communication link, so that in the face of situations such as overhead blind spot avoidance, transit avoidance and cloud cover, the communication link can be quickly and accurately re-established by predicting and correcting the servo pointing, thereby improving the stability and reliability of the communication link. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a flow chart of a method for reconstructing a broken link in satellite-to-ground laser communication based on a downlink spot miss amount provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the architecture of the ground-side coarse tracking of satellite-to-ground laser communication provided by an embodiment of the present invention; Figure 3 It is a schematic structural diagram of a satellite-to-ground laser communication link-breaking reconstruction device based on the downlink spot miss amount provided by an embodiment of the present invention; Figure 4 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In satellite communications, the downlink signal spot refers to the intersection area between the concentrated radio beam emitted by the satellite to the ground and the earth's surface. The spot miss amount refers to the deviation of the spot from the predetermined target position. In satellite laser communications, the spot miss amount is a key technical indicator, which measures the positioning accuracy of the spot at the receiving end. Specifically, the spot miss amount refers to the deviation distance of the spot from the center position of the receiver. This deviation distance can be calculated by the image processing module and used to adjust the control system to ensure that the spot can be accurately aligned with the center of the receiver. In the actual tracking process, the system will use the spot miss amount to dynamically adjust the position of the receiver to keep the spot in the optimal position in the center of the receiver, thereby achieving efficient signal reception and processing.

[0020] Figure 1 It is a flow chart of a method for reconstructing a broken link in satellite-to-ground laser communication based on the downlink spot off-target amount provided by an embodiment of the present invention.

[0021] See also Figure 1 The satellite-to-ground laser communication broken link reconstruction method based on the downlink spot miss amount may include the following steps 101 to 107.

[0022] 101. When a downlink signal spot appears in the coarse tracking field of view, the ground station is controlled to start the coarse tracking closed-loop process to establish a satellite-to-ground laser communication link.

[0023] Satellite tracking can generally be divided into coarse tracking and fine tracking. For technicians in this field, coarse tracking and fine tracking are both clear concepts. Coarse tracking and fine tracking can also be replaced by a first preset tracking method and a second preset tracking method, respectively. The tracking accuracy of the second preset tracking method is greater than that of the first preset tracking method.

[0024] 102. Determine the spot miss amount of the downlink signal spot, correct the servo pointing based on the spot miss amount, and record the spot miss amount.

[0025] This step generally includes: Image acquisition: The coarse tracking camera collects images in the coarse tracking field of view in real time. These images contain the location information of the downlink signal spot.

[0026] Image preprocessing: The collected images are preprocessed, including denoising, contrast enhancement, and edge detection to improve the accuracy of spot position detection.

[0027] Spot position extraction: Use image processing algorithms (such as centroid algorithm, template matching or deep learning algorithm) to extract the centroid position coordinates of the downlink signal spot from the pre-processed image. The centroid position is usually regarded as the center position of the spot.

[0028] Calculate the miss amount: Compare the extracted spot centroid position coordinates with the preset target position coordinates to calculate the spot miss amount.

[0029] The spot miss amount usually includes two components, such as: Azimuth miss amount: indicates the deviation of the light spot in the horizontal direction; Pitch miss amount: indicates the deviation of the light spot in the vertical direction.

[0030] 103. When the downlink signal spot in the coarse tracking field of view disappears, close the coarse tracking loop to disconnect the satellite-to-ground laser communication link.

[0031] 104. Based on the recorded spot miss amount, predict the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears.

[0032] Specifically, based on the recorded spot miss amount, predicting the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears may include: Obtain a preset initial parameter vector and construct a nonlinear change function of the initial parameter vector in the time dimension; Based on the nonlinear variation function, determine the partial derivative of the initial parameter vector; Construct the Jacobian matrix based on the partial derivatives of the initial parameter vector; Based on the Jacobian matrix, the initial parameter vector is iteratively updated to obtain the parameter update result; Determine whether the parameter update result meets the preset iteration stop condition; If so, stop iterating and updating the initial parameter vector, and use the parameter update result after stopping the iterative update to fit the nonlinear change function; Based on the fitted nonlinear variation function, the predicted correction value of the servo pointing at each moment after the downlink signal spot disappears is obtained.

[0033] If not, continue to iterate and update the initial parameter vector.

[0034] This step can more accurately predict the correction amount of servo pointing by constructing a nonlinear variation function and Jacobian matrix, and iteratively updating the parameter vector, thereby improving the accuracy of broken link reconstruction.

[0035] 105. Based on the predicted correction amount at each moment, the servo orientation is corrected to obtain the predicted corrected orientation of the servo at each moment.

[0036] 106. When a downlink signal spot appears in the coarse tracking field of view, find the predicted correction direction corresponding to the moment when the downlink signal spot appears.

[0037] In this step, when the downlink signal spot appears in the coarse tracking field of view, it means when the downlink signal spot appears again in the coarse tracking field of view. The previous step has predicted the predicted correction direction at each moment after the link is broken. Therefore, when the downlink signal spot appears again, the predicted correction direction at the moment when the downlink signal spot appears again can be determined.

[0038] 107. Based on the corresponding predicted and corrected pointing, a coarse tracking loop is started to reconstruct the satellite-to-ground laser communication link.

[0039] In this embodiment, when the downlink signal spot disappears in the coarse tracking field of view, the coarse tracking closed loop is closed to disconnect the satellite-to-ground laser communication link; based on the recorded spot off-target amount, the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears is predicted; based on the predicted correction amount at each moment, the servo pointing is corrected to obtain the predicted corrected pointing of the servo at each moment; when the downlink signal spot appears in the coarse tracking field of view, the predicted corrected pointing corresponding to the moment when the downlink signal spot appears is found; based on the corresponding predicted corrected pointing, the coarse tracking closed loop is opened to rebuild the satellite-to-ground laser communication link, so that in the face of overhead blind spot avoidance, transit avoidance and cloud cover, the communication link can be quickly and accurately re-established by predicting and correcting the servo pointing, thereby improving the stability and reliability of the communication link.

[0040] In one embodiment of the present specification, the nonlinear change function is shown in the following formula (1): (1); among which, For time, is the initial parameter vector in degrees.

[0041] The Jacobian matrix is ​​shown in the following formula (2): (2); among which, is the element in the i-th row and j-th column of the Jacobian matrix J; , n is the number of samples, m is the number of parameters; i is the index of the number of samples, i is from 1 to n; j is the index of the number of parameters, j is from 1 to m.

[0042] In this embodiment, the relationship between the spot miss amount and time, as well as the influence of the parameter vector on the model are quantified, which provides a mathematical basis for iterative updating of the parameter vector and is conducive to improving the accuracy of prediction.

[0043] In one embodiment of the present specification, the initial parameter vector is iteratively updated to obtain a parameter update result, including: The initial parameter vector is iteratively updated using Loewenberg-Marquardt to obtain the parameter update result.

[0044] In this embodiment, the efficiency and stability of the Loewenberg-Marquardt algorithm are utilized to optimize the updating process of the parameter vector to obtain a more accurate prediction correction value.

[0045] In an embodiment of the present specification, the initial parameter vector is iteratively updated using the Loewenberg-Marquardt method to obtain a parameter update result, including: (3); where k in formula (3) is the number of iterations; is the initial parameter vector for the kth iteration; is the initial parameter vector for the k+1th iteration; is the update amount of the initial parameter vector in the kth iteration. It can be expressed by the following formula (4).

[0046] (4); among which, is the adjustment factor; I is the unit matrix; is the residual vector. It can be expressed by the following formula (5).

[0047] (5); among which, is the spot off-target amount.

[0048] In this embodiment, the update amount of the parameter vector in each iteration is accurately calculated, thereby gradually approaching the optimal parameter vector. is the spot miss amount, which may include the azimuth miss amount and the pitch miss amount of the servo. That is to say, the above formulas can eventually predict the azimuth miss amount and the pitch miss amount of the servo.

[0049] In one embodiment of the present specification, the parameter update result after stopping the iterative update is used to fit the nonlinear change function, including the following formula (6): (6); among which, is the spot off-target amount at time t; The parameter update result after stopping the iteration update.

[0050] In this embodiment, it is possible to accurately predict the spot off-target amount at a specific moment according to the optimal parameter vector, thereby providing a basis for the correction of the servo pointing.

[0051] In one embodiment of the present specification, the preset iteration stop condition includes: The residual sum of squares of the residual vector converges; or The spot off-target amount is less than the preset convergence accuracy.

[0052] In this embodiment, by using the above-mentioned preset iteration stop condition, excessive iteration can be avoided, computing resources can be saved, and the accuracy of the predicted correction amount can be ensured. In addition, the preset maximum number of iterations can also be used as the preset iteration stop condition.

[0053] In one embodiment of the present specification, correcting the servo pointing based on the spot miss amount may include: Based on the spot miss amount, the proportional-integral-derivative (PID) method is used to correct the servo pointing.

[0054] In this embodiment, the stability and robustness of PID control are utilized to correct the servo pointing in real time, so as to quickly and accurately re-establish the communication link.

[0055] In some other embodiments of the present invention, before determining the spot miss amount of the downlink signal spot, the following steps may be included: Spot detection and preprocessing: Real-time detection of the image in the coarse tracking field of view, identification of the location information of the downlink signal spot, and preprocessing of the detected spot image, including denoising, contrast enhancement and edge detection, to improve the accuracy of spot position detection; Spot position extraction: Through the image processing algorithm, the centroid position coordinates of the downlink signal spot are extracted from the pre-processed image as the reference point of the spot position; Calculation of the light spot miss amount: Calculate the light spot miss amount based on the extracted light spot centroid position coordinates and the preset target position coordinates. The light spot miss amount includes the azimuth miss amount and the pitch miss amount, which represent the deviation of the light spot in the horizontal and vertical directions respectively.

[0056] In some other embodiments of the present invention, when correcting the servo pointing based on the spot miss amount, the following steps may also be included: PID parameter optimization: According to the historical spot miss data and servo correction response characteristics, the parameters of the proportional-integral-derivative (PID) controller are dynamically adjusted to optimize the performance of the servo pointing correction and reduce overshoot and steady-state error during the correction process; Multi-dimensional correction strategy: Combine the azimuth and pitch components of the spot miss amount to independently correct the azimuth and pitch axes of the servo system to achieve precise adjustment of the spot position; Correction effect evaluation and feedback: After each correction, re-detect the position of the downlink signal light spot, calculate the corrected light spot off-target amount, and compare it with the light spot off-target amount before correction to evaluate the correction effect; if the corrected light spot off-target amount does not meet the preset accuracy requirements, adjust the PID parameters or correction strategy according to the correction effect, and correct again until the light spot off-target amount meets the requirements for establishing a communication link.

[0057] In some other embodiments of the present invention, before determining the spot miss amount of the downlink signal spot, the following steps may be included: Spot detection with multi-source data fusion: The light spot image data is obtained from the image sensor in the coarse tracking field of view, and the downlink signal light spot is detected through a multi-source data fusion algorithm in combination with satellite orbit prediction data, meteorological data, and historical communication link data; The multi-source data fusion algorithm includes but is not limited to Bayesian fusion, Kalman filter fusion or neural network fusion to improve the accuracy and reliability of light spot detection.

[0058] Spot feature extraction and enhancement: Extract features from the detected light spot image, the extracted features include the centroid position of the light spot, light intensity distribution, light spot shape and edge features; Based on the extracted features, the spot image is enhanced, including spot contrast enhancement, background noise suppression and spot shape correction, to improve the accuracy of spot miss amount calculation.

[0059] Dynamic spot miss amount calculation model: According to the extracted light spot features and the preset target position coordinates, a dynamic light spot miss distance calculation model is established, which can adapt to factors such as light spot shape changes, light intensity fluctuations and atmospheric disturbances in real time; The dynamic spot miss amount calculation model is trained based on a machine learning algorithm, and the training data includes historical spot image data, spot miss amount data, and environmental parameter data to improve the generalization ability and prediction accuracy of the model, thereby calculating the spot miss amount.

[0060] Multi-dimensional decomposition of spot off-target amount: The calculated spot miss amount is decomposed into azimuth miss amount, elevation miss amount and spot shape deviation amount, wherein the spot shape deviation amount is used to evaluate the ellipticity and symmetry of the spot; According to the multi-dimensional decomposition results, the spot off-target amount is weighted to highlight the main deviation direction (the weight of the large deviation is relatively large) and optimize the subsequent servo pointing correction strategy.

[0061] Figure 2Schematic diagram of the architecture of the ground-side coarse tracking of satellite-to-ground laser communication provided by an embodiment of the present invention. Figure 2 , the coarse tracking of the present invention is introduced. The transmitting module at the ground end can transmit an uplink beam to the satellite. The coarse tracking optical branch and the coarse tracking camera can also be collectively regarded as a rear optical path module.

[0062] Step 1: The ground end receives the laser signal sent by the satellite to the ground end through the optical antenna, that is, the downlink beam, and guides the downlink beam to the receiving primary mirror.

[0063] Step 2: The receiving primary mirror focuses the received downlink beam into the subsequent coarse tracking optical branch.

[0064] Step 3: The coarse tracking optical branch can separate a portion of the downlink light beam for coarse tracking and branch it to the coarse tracking camera.

[0065] Step 4: The coarse tracking camera is used to capture the downlink beam images, which contain the position information of the light spot. The deviation of the beam is determined by detecting the position of the light spot. The captured downlink light capture images are then sent to the image processing server.

[0066] Step 5: The image processing server receives the downlink light capture image from the coarse tracking camera, processes and analyzes it to determine the precise position and deviation of the light beam. Based on this data, the image processing server generates a corresponding control signal to instruct the servo system how to adjust the direction of the optical antenna, that is, to perform servo correction.

[0067] Step 6: The servo calculates the required servo correction based on the analysis results of the image processing server, and then adjusts the angle of the optical antenna or the receiving primary mirror through the servo system to reduce the deviation of the light beam and achieve coarse tracking of the downlink light beam.

[0068] The entire process described above is a closed-loop control system that ensures that the downlink beam can be stably received by the ground station through continuous detection, processing and correction. The purpose of coarse tracking is to quickly capture and roughly align the satellite's downlink beam, providing a basis for subsequent fine tracking.

[0069] The coarse tracking closed loop is the initial alignment process of the ground station or satellite to recapture the other party's signal after the laser communication link is interrupted. When a downlink signal spot appears in the coarse tracking field of view of the ground station, the ground station starts the coarse tracking closed loop process. The coarse tracking closed loop can use the PID (proportional-integral-differential) algorithm to correct the servo pointing to reduce the off-target amount of the spot (that is, the deviation between the spot and the expected target). This process records the off-target amount of the spot and provides data support for the subsequent prediction of the servo correction amount. The purpose of the coarse tracking closed loop is to quickly align the laser beam to a roughly correct direction so that the other party's signal can be captured.

[0070] The fine tracking loop is the process of further improving the accuracy of laser beam alignment after the coarse tracking loop. When the coarse tracking loop successfully captures the signal, the fine tracking loop starts to work to achieve higher-precision alignment. The fine tracking loop may use more advanced control algorithms, such as Kalman filtering, to compensate for errors caused by atmospheric disturbances, mechanical vibrations, etc. This process ensures that the laser beam can be stably aligned with the target, thereby establishing a high-quality laser communication link. The purpose of the fine tracking loop is to achieve high-precision alignment, ensure the stability of communication and the accuracy of data transmission. In the satellite-to-ground laser communication link reconstruction method, the coarse tracking loop and the fine tracking loop work together to ensure that the communication link can be quickly and accurately reestablished after the link is interrupted. The coarse tracking loop provides a fast initial alignment, while the fine tracking loop provides finer adjustments on this basis to achieve stable communication.

[0071] Based on the same general inventive concept, the present invention also protects a satellite-to-ground laser communication link reconstruction device based on the downlink spot miss amount, such as Figure 3 As shown, Figure 3 It is a schematic diagram of the structure of the satellite-to-ground laser communication broken link reconstruction device based on the downlink spot miss amount provided by an embodiment of the present invention. The satellite-to-ground laser communication broken link reconstruction device based on the downlink spot miss amount provided by the present invention is described below, and the satellite-to-ground laser communication broken link reconstruction device based on the downlink spot miss amount described below and the satellite-to-ground laser communication broken link reconstruction method based on the downlink spot miss amount described above can correspond to each other.

[0072] The satellite-to-ground laser communication broken link reconstruction device based on the downlink spot miss amount includes a coarse tracking module 301, a spot miss amount module 302, a closing module 303, a prediction module 304, a correction module 305, a search module 306 and a reconstruction module 307.

[0073] When a downlink signal spot appears in the coarse tracking field of view, the coarse tracking module 301 controls the ground station to start the coarse tracking closed-loop process to establish a satellite-to-ground laser communication link; The light spot miss amount module 302 determines the light spot miss amount of the downlink signal light spot, corrects the servo pointing based on the light spot miss amount, and records the light spot miss amount; When the downlink signal spot in the coarse tracking field of view disappears, the closing module 303 closes the coarse tracking closed loop to disconnect the satellite-to-ground laser communication link; The prediction module 304 predicts the predicted correction amount of the servo pointing at each moment after the downlink signal light spot disappears based on the recorded light spot off-target amount; The correction module 305 corrects the servo orientation based on the predicted correction amount at each moment, and obtains the predicted corrected orientation of the servo at each moment; When a downlink signal spot appears in the coarse tracking field of view, the search module 306 searches for the predicted correction direction corresponding to the time when the downlink signal spot appears; The reconstruction module 307 starts a coarse tracking loop based on the corresponding predicted corrected pointing to reconstruct the satellite-to-ground laser communication link.

[0074] Figure 4 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

[0075] like Figure 4 As shown, the electronic device may include: a processor 410, a communications interface 420, a memory 430 and a communication bus 440, wherein the processor 410, the communications interface 420 and the memory 430 communicate with each other through the communication bus 440. The processor 410 may call the logic instructions in the memory 430 to execute the satellite-to-ground laser communication broken link reconstruction method based on the downlink spot miss amount.

[0076] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0077] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the satellite-to-ground laser communication broken link reconstruction method based on the downlink light spot off-target amount provided by the above-mentioned methods.

[0078] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the satellite-to-ground laser communication broken link reconstruction method based on the downlink light spot off-target amount provided by the above-mentioned methods.

[0079] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0080] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for reconstructing a satellite-to-ground laser communication link break based on the amount of downlink spot miss, characterized in that: include: When a downlink signal spot appears in the coarse tracking field of view, the ground station is controlled to start the coarse tracking closed-loop process to establish a satellite-to-ground laser communication link; Determine the spot miss amount of the downlink signal spot, correct the servo pointing based on the spot miss amount, and record the spot miss amount; When the downlink signal spot in the coarse tracking field of view disappears, closing the coarse tracking closed loop to disconnect the satellite-to-ground laser communication link; Based on the recorded spot miss amount, predict the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears; Based on the predicted correction amount at each moment, the servo orientation is corrected to obtain the predicted corrected orientation of the servo at each moment; When a downlink signal light spot appears in the coarse tracking field of view, searching for the predicted correction direction corresponding to the moment when the downlink signal light spot appears; Based on the corresponding predicted and corrected pointing, a coarse tracking loop is started to reconstruct the satellite-to-ground laser communication link.

2. The method for reconstructing a satellite-to-ground laser communication link break based on the downlink spot miss amount according to claim 1 is characterized in that: The predicted correction amount of the servo pointing at each moment after the downlink signal light spot disappears based on the recorded light spot off-target amount comprises: Obtaining a preset initial parameter vector, and constructing a nonlinear variation function of the initial parameter vector in the time dimension; Based on the nonlinear variation function, determining the partial derivative of the initial parameter vector; Constructing a Jacobian matrix based on partial derivatives of the initial parameter vector; Based on the Jacobian matrix, the initial parameter vector is iteratively updated to obtain a parameter update result; Determine whether the parameter update result meets the preset iteration stop condition; If so, stop iterating and updating the initial parameter vector, and use the parameter update result after stopping the iterative update to fit the nonlinear change function; Based on the fitted nonlinear variation function, the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears is obtained.

3. The method for reconstructing a satellite-to-ground laser communication link break based on the downlink spot miss amount according to claim 2 is characterized in that: The nonlinear change function is shown in the following formula: ;in, For time, is the initial parameter vector, in degrees; The Jacobian matrix is ​​shown in the following formula: ;in, is the element in the i-th row and j-th column of the Jacobian matrix J; , n is the number of samples, m is the number of parameters; i is the index of the number of samples, i is from 1 to n; j is the index of the number of parameters, j is from 1 to m.

4. The method for reconstructing a broken link in satellite-to-ground laser communication based on the amount of downlink spot miss according to claim 3 is characterized in that: The iterative updating of the initial parameter vector to obtain the parameter update result includes: The initial parameter vector is iteratively updated using Loewenberg-Marquardt to obtain the parameter update result.

5. The method for reconstructing a broken link in satellite-to-ground laser communication based on the amount of downlink spot miss according to claim 4 is characterized in that: The initial parameter vector is iteratively updated using Loewenberg-Marquardt to obtain a parameter update result, including: ; Where k is the number of iterations; is the initial parameter vector for the kth iteration; is the initial parameter vector for the k+1th iteration; is the update amount of the initial parameter vector in the kth iteration; in, ;in, is the adjustment factor; I is the unit matrix; is the residual vector; in, ; is the spot off-target amount.

6. The method for reconstructing a satellite-to-ground laser communication link break based on the downlink spot miss amount according to claim 5 is characterized in that: The method of fitting the nonlinear change function using the parameter update result after stopping the iterative update comprises: ;in, is the spot off-target amount at time t; The parameter update result after stopping the iteration update.

7. The method for reconstructing a broken link in satellite-to-ground laser communication based on the amount of downlink spot miss according to claim 4 is characterized in that: The preset iteration stop condition includes: The residual sum of squares of the residual vector converges; or The spot off-target amount is less than the preset convergence accuracy.

8. The method for reconstructing a broken link in satellite-to-ground laser communication based on the amount of downlink spot miss according to claim 1 is characterized in that: The correcting the servo pointing based on the light spot off-target amount comprises: Based on the spot miss amount, PID is used to correct the servo pointing.

9. A satellite-to-ground laser communication link reconstruction device based on the downlink spot miss amount, characterized in that: include: The coarse tracking module controls the ground station to start the coarse tracking closed-loop process to establish a satellite-to-ground laser communication link when a downlink signal spot appears in the coarse tracking field of view; A light spot miss amount module is used to determine the light spot miss amount of the downlink signal light spot, correct the servo pointing based on the light spot miss amount, and record the light spot miss amount; A closing module, when the downlink signal spot in the coarse tracking field of view disappears, closes the coarse tracking closed loop to disconnect the satellite-to-ground laser communication link; A prediction module, based on the recorded spot miss amount, predicts the predicted correction amount of the servo pointing at each moment after the downlink signal spot disappears; A correction module, which corrects the servo orientation based on the predicted correction amount at each moment to obtain the predicted corrected orientation of the servo at each moment; A search module, when a downlink signal light spot appears in the coarse tracking field of view, searches for the predicted correction direction corresponding to the moment when the downlink signal light spot appears; The reconstruction module, based on the corresponding predicted correction pointing, starts the coarse tracking loop to reconstruct the satellite-to-ground laser communication link.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, a method for reconstructing a broken link in satellite-to-ground laser communication based on the downlink spot miss amount as described in any one of claims 1 to 8 is implemented.

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