A method for correcting on-orbit pointing deviation of a two-dimensional mechanical antenna for a spot beam of a plate satellite

Abstract

The application discloses a kind of on-orbit pointing deviation correction methods for flat panel satellite point beam two-dimensional mechanical antenna, the method comprises: on-orbit real-time acquisition antenna pointing ground station azimuth, elevation angle and telemetry information;Actual and theoretical signal gain difference is calculated inversely;Whether the gain difference meets the pointing accuracy requirement is judged, if not, the deviation angle of actual and theoretical pointing vector and actual pointing vector are calculated inversely;Optimal theoretical pointing vector is solved using Gauss-Newton method;The installation matrix of matching theory pointing is solved and the antenna installation matrix is adjusted;The above steps are repeated to form a closed loop, until the gain difference meets the accuracy requirement.The application uses three-dimensional installation matrix correction instead of traditional zero position correction, combined with closed-loop feedback and nonlinear optimization, realizes multi-source error high-precision compensation, and has strong engineering implementability, meets the on-orbit multi-satellite batch correction demand of flat panel satellite, significantly improves the reliability and data transmission rate of communication system.

Description

Technical Field

[0001] This invention relates to the field of satellite communication technology, and specifically to an on-orbit pointing deviation correction method for a two-dimensional mechanical antenna with a point beam for flat-panel satellites. Background Technology

[0002] In recent years, satellite communication technology has developed rapidly, and the requirements for data rate and timeliness of satellites have been increasing. Spot beam antennas, due to their high effective omnidirectional radiation power and ability to precisely control the pointing area, can achieve high gain while avoiding signal interference, and can effectively and reliably transmit data to ground stations or relay satellites. Therefore, they are widely used in satellite internet.

[0003] However, the narrow beamwidth of spot beams and the inherent characteristics of flat-panel satellites, such as their large aspect ratio, high solar panel flexibility, and limited antenna mounting surface, pose significant challenges to the pointing accuracy of two-dimensional mechanical antennas with spot beams. Numerous and complex factors influence antenna pointing accuracy, including installation errors in the two-dimensional rotating mechanism, orthogonality accuracy of the mechanism, zero-position compensation accuracy of the drive shaft, satellite platform attitude pointing deviation, antenna mounting surface errors, and pointing angle calculation errors. These errors are intertwined and difficult to completely eliminate through ground preprocessing. During on-orbit operation, they continuously affect antenna pointing accuracy, leading to degraded communication quality, reduced data transmission rates, and in severe cases, even communication link interruptions.

[0004] Existing technologies for correcting satellite antenna pointing deviations mostly employ single-axis or dual-axis zero-position correction methods, which can only compensate for errors in some directions and cannot achieve comprehensive error correction in three-dimensional space, resulting in limited correction accuracy. Furthermore, existing methods lack a closed-loop feedback mechanism, making it difficult to dynamically adjust the correction strategy based on real-time on-orbit status, and thus failing to meet the engineering requirements for batch correction of multiple flat-panel satellites in orbit. Therefore, there is an urgent need for a high-precision, engineering-feasible on-orbit pointing deviation correction method to solve the aforementioned technical problems. Summary of the Invention

[0005] This invention provides an on-orbit pointing deviation correction method for a two-dimensional mechanical antenna with a point beam for flat-panel satellites. By real-time on-orbit data acquisition, error quantization analysis, mathematical optimization solution, and closed-loop feedback adjustment, high-precision correction of antenna pointing deviation is achieved.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for correcting the pointing deviation of a two-dimensional mechanical antenna with a point beam for flat-panel satellites includes the following steps:

[0008] Step S1: In real time on orbit, acquire the azimuth angle, elevation angle, and uplink signal power detection (AGC telemetry) information of the antenna pointing to the ground station;

[0009] Step S2: Based on the real-time uplink signal AGC received from the ground and the EIRP of the signal transmitted by the ground terminal, calculate the gain difference Δ_gain_antenna between the actual signal and the theoretical signal.

[0010] Step S3: Determine whether the gain difference Δ_gain_antenna meets the pointing accuracy requirements. If it does, stop the correction; otherwise, proceed with the next steps.

[0011] Step S4: Based on the antenna directional gain diagram and the gain difference Δ_gain_antenna, calculate the deviation angle θ between the actual pointing vector of the current satellite to the ground station and the theoretical pointing vector;

[0012] Step S5: Based on the azimuth and elevation angle information, calculate the actual pointing vector V_actual_antenna of the current satellite to the ground station;

[0013] Step S6: Based on the deviation angle θ and the actual pointing vector V_actual_antenna, the problem is transformed into a mathematical nonlinear problem. The optimal theoretical pointing vector V_ideal_antenna is solved by using the Gauss-Newton method.

[0014] Step S7: Based on the theoretical pointing vector V_ideal_antenna and the installation matrix preset before antenna transmission, calculate the installation matrix information that matches the theoretical pointing.

[0015] Step S8: Adjust the antenna mounting matrix according to the mounting matrix information, then return to step S1 and repeat until the gain difference Δ_gain_antenna meets the pointing accuracy requirements.

[0016] Furthermore, the calculation expression for the gain difference Δ_gain_antenna mentioned in step S2 is: Δ_gain_antenna = P G -L+G A +G R -P AGC Among them, P G EIRP for ground-based in-band remote control signals, in dBm; L is the signal spatial loss, in dB; G A Satellite antenna gain, in dB; G R P represents the gain of the satellite transponder (including LNA) accompanying remote control signal, in dB. AGC EIRP of the in-path remote control signal calculated using AGC, in dBm.

[0017] Furthermore, the PAGC Through the functional relationship P AGC =f(V) AGC The calculation yields f, where f is V. AGC With P AGC The quantitative mapping function between them, specifically P AGC =f(V AGC )=K1×V AGC ²+K2×V AGC +K3, where: K1, K2, and K3 are fixed constants obtained from the ground experiment fitting; V AGC This is the average value of the uplink AGC in QV mode of the TM24015 A telemetry unit and the uplink AGC in QV mode of the TM24083 B telemetry unit. QV mode is a high-throughput communication mode that coordinates the Q band and V band. The TM24015 A and TM24083 B are dual-redundant terminals for collecting uplink AGC telemetry data in QV mode.

[0018] Furthermore, the pointing accuracy requirement mentioned in step S3 is the gain error threshold corresponding to the point beam antenna, and the threshold is preset according to the requirements of the satellite communication mission.

[0019] Furthermore, in step S4, when calculating the deviation angle θ, a pre-stored antenna directional gain map database is invoked, which contains antenna gain data at different pointing angles.

[0020] Furthermore, the inverse calculation process of the actual pointing vector V_actual_antenna in step S5 is to convert the azimuth and elevation angles into vector representations in a three-dimensional spatial coordinate system.

[0021] Furthermore, in step S6, when using the Gauss-Newton method to solve the problem, the objective function is to minimize the deviation between the actual pointing vector and the theoretical pointing vector, and the optimal solution is obtained through iterative convergence.

[0022] Furthermore, the calculation of the installation matrix information in step S7 is based on the mapping relationship between the theoretical pointing vector V_ideal_antenna and the antenna installation reference coordinate system.

[0023] Furthermore, the azimuth and elevation angles are directly and in real-time collected by an angle sensor integrated into the antenna's two-dimensional rotation mechanism, which directly collects the raw data of the azimuth and elevation angles of the antenna pointing towards the ground station.

[0024] Furthermore, the AGC telemetry information is transmitted to the ground station in real time via the satellite telemetry and control link.

[0025] This invention uses the deviation angle θ to reflect the angular difference between the actual and theoretical pointing. The actual pointing vector V_actual_antenna clarifies the current spatial position of the pointing, providing complete input parameters for the Gauss-Newton method and realizing collaborative modeling of angle deviation and spatial position. The optimal theoretical pointing vector solved by the Gauss-Newton method provides a target benchmark for the installation matrix calculation. The installation matrix adjustment then transforms the mathematically optimal solution into engineering practice actions, ensuring the feasibility of the correction strategy. A closed-loop feedback mechanism runs through the entire correction process. Through repeated data acquisition, error calculation, and adjustment steps, the accumulated errors of each link are dynamically corrected, realizing a virtuous cycle of acquisition-calculation-adjustment-reacquisition, ensuring continuous improvement in correction accuracy.

[0026] This invention uses an installation matrix for three-dimensional error correction, replacing the traditional single-axis or dual-axis zero-position correction. It can comprehensively compensate for multi-source errors such as antenna installation, satellite attitude, and mechanism movement. The pointing accuracy after correction is better than 0.2°, which is more than 50% higher than the existing methods.

[0027] Based on real-time on-orbit telemetry data and the mature Gauss-Newton numerical solution method, it can be achieved through software algorithm optimization without the need for additional complex hardware equipment. It is compatible with the hardware architecture of flat panel satellites and can meet the needs of batch on-orbit correction for multiple satellites.

[0028] Through the closed-loop feedback mechanism, it can respond in real time to changes in the satellite's on-orbit operating status, dynamically adjust and correct strategies, effectively cope with dynamic error factors such as solar panel deflection and orbital perturbation, and ensure the stability of pointing accuracy during long-term operation.

[0029] By transforming signal gain error into angular deviation and spatial vector deviation through a mathematical model, the error can be accurately quantified, avoiding the subjectivity and ambiguity of error estimation in traditional methods and providing a scientific basis for the formulation of correction strategies. Through high-precision pointing deviation correction, signal interference is reduced, the utilization rate of effective omnidirectional radiation power is improved, the data transmission rate is increased by more than 30%, the probability of communication link interruption is reduced by 80%, and the reliability and stability of satellite communication systems are significantly improved.

[0030] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the on-orbit pointing deviation correction method for a two-dimensional mechanical antenna with a point beam for flat-panel satellites according to the present invention. Detailed Implementation

[0032] The present invention will now be further described in conjunction with the accompanying drawings and relevant knowledge, and will be described clearly and completely. Obviously, the described applications are only some embodiments of the present invention, and not all embodiments.

[0033] In existing technologies, ground-based precision measurements using a point-beam two-dimensional mechanical antenna and a flat-panel satellite can eliminate errors caused by antenna installation and satellite assembly. However, a certain pointing deviation still exists in orbit, severely affecting the antenna's pointing accuracy. To further improve the antenna's on-orbit pointing accuracy and reduce the impact of inherent pointing deviation, this invention proposes an on-orbit pointing deviation correction method for point-beam two-dimensional mechanical antennas on flat-panel satellites. This method cleverly transforms the antenna pointing deviation problem into a mathematically nonlinear problem, and by introducing the Gauss-Newton method, the mathematically optimal solution to this nonlinear problem can be effectively obtained. After obtaining the mathematically optimal solution, this invention proposes to inject the installation matrix obtained by back-calculating the mathematically optimal solution onto the satellite. Then, the gain difference Δ_gain_antenna between the actual signal and the theoretical signal is calculated again using real-time on-orbit telemetry data. Correction stops only after the gain difference Δ_gain_antenna is determined to meet the pointing accuracy requirements. The entire correction method can obtain a solution that meets the antenna's on-orbit pointing accuracy requirements through a closed-loop process, ensuring the effectiveness of the on-orbit correction method. It has high engineering feasibility and can meet the requirements for batch correction of multiple flat-panel satellites in orbit. The specific technical solution is as follows:

[0034] Reference Figure 1 As shown, this invention discloses an on-orbit pointing deviation correction method for a two-dimensional mechanical antenna with a point beam for flat-panel satellites, comprising the following steps:

[0035] Step S1: In real time on orbit, acquire the azimuth angle, elevation angle, and uplink signal power detection information of the antenna pointing to the ground station;

[0036] Step S2: Based on the real-time uplink signal power detection information received from the ground and the EIRP of the signal transmitted by the ground terminal, calculate the gain difference Δ_gain_antenna between the actual signal and the theoretical signal.

[0037] Step S3: Determine whether the gain difference Δ_gain_antenna meets the pointing accuracy requirements. If it does, stop the correction; otherwise, proceed with the next steps.

[0038] Step S4: Based on the antenna directional gain diagram and the gain difference Δ_gain_antenna, calculate the deviation angle θ between the actual pointing vector of the satellite to the ground station and the theoretical pointing vector; This invention uses the gain difference Δ_gain_antenna between the actual signal and the theoretical signal and the antenna gain directional diagram to calculate the deviation angle θ between the actual pointing vector of the satellite to the ground station and the theoretical pointing vector, thus converting the signal error into an angle error;

[0039] Step S5: Based on the azimuth and elevation angle information, calculate the actual pointing vector V_actual_antenna of the current satellite to the ground station. This invention, by making full use of on-orbit real-time telemetry, calculates the gain difference Δ_gain_antenna between the actual signal and the theoretical signal, and the actual pointing vector V_actual_antenna of the current satellite to the ground station. Thus, the pointing angle deviation of the antenna is transformed into a three-dimensional spatial vector, and then into a mathematical problem of fitting three-dimensional spatial error data.

[0040] Step S6: Based on the deviation angle θ and the actual pointing vector V_actual_antenna, the problem is transformed into a mathematical nonlinear problem. The optimal theoretical pointing vector V_ideal_antenna is obtained by using the Gauss-Newton method. This invention effectively transforms the pointing correction problem into a mathematical nonlinear problem by back-calculating the current satellite pointing vector V_actual_antenna to the ground station and the deviation angle θ between the current satellite pointing vector to the ground station and the theoretical pointing vector. The Gauss-Newton method is then used to solve this nonlinear problem to obtain the current mathematically optimal solution.

[0041] Step S7: Based on the theoretical pointing vector V_ideal_antenna and the installation matrix preset before antenna transmission, calculate the installation matrix information that matches the theoretical pointing.

[0042] Step S8: Adjust the antenna installation matrix according to the installation matrix information, then return to step S1 and repeat until the gain difference Δ_gain_antenna meets the pointing accuracy requirements; After solving the mathematical optimal solution of the nonlinear problem, this invention back-calculates the corrected installation matrix and injects it into the satellite. Then, through real-time telemetry in orbit, it back-calculates the gain difference Δ_gain_antenna between the actual signal and the theoretical signal for judgment. Instead of using X-axis and Y-axis zero-position correction, it uses the installation matrix for error correction, which can perform three-dimensional error correction and improve the correction accuracy.

[0043] This invention acquires azimuth, elevation, and AGC telemetry information of the antenna pointing to the ground station in real time on orbit; calculates the gain difference Δ_gain_antenna between the actual and theoretical signals; determines whether Δ_gain_antenna meets the pointing accuracy requirements; if not, it calculates the deviation angle θ between the actual and theoretical pointing vectors and the actual pointing vector V_actual_antenna; solves for the optimal theoretical pointing vector V_ideal_antenna using the Gauss-Newton method; calculates and adjusts the installation matrix to match the theoretical pointing; repeats the above steps to form a closed loop until Δ_gain_antenna meets the accuracy requirements. This invention uses three-dimensional installation matrix correction to replace traditional zero-position correction, combined with closed-loop feedback and nonlinear optimization, to achieve high-precision compensation for multi-source errors, with pointing accuracy better than 0.2°. It has strong engineering feasibility, meets the on-orbit batch correction requirements of flat-panel satellites, and significantly improves the reliability of communication systems and data transmission rates.

[0044] In a preferred embodiment of the present invention, during the real-time data acquisition process in orbit, the azimuth angle, elevation angle and uplink signal AGC telemetry information of the antenna pointing to the ground station are obtained in real time by relying on the measurement equipment and telemetry and control link carried by the flat-panel satellite, so as to provide basic data support for subsequent deviation correction.

[0045] Specifically, the flat-panel satellite carries an attitude measurement device consisting of a star sensor and a gyroscope, along with a GNSS receiver as its orbit measurement equipment. The star sensor acquires high-precision satellite attitude information, while the gyroscope supplements dynamic attitude measurement data to achieve platform attitude data acquisition at a frequency of 10Hz. The GNSS receiver tracks and captures navigation satellites in real time to calculate the satellite's real-time position information. Based on the satellite's real-time attitude and orbit data, the elevation and azimuth angles of the antenna-to-ground gateway vector in the antenna coordinate system are calculated. The entire calculation process ensures that the data is real-time and meets the on-orbit correction requirements. The antenna's two-dimensional rotation mechanism integrates an angle sensor to directly acquire the raw azimuth and elevation angle data pointing from the antenna to the ground station. This data complements and verifies the elevation and azimuth angle data calculated from the satellite's real-time attitude and orbit data, further improving the accuracy of the angle data. Uplink AGC telemetry information is transmitted to the ground station via the satellite telemetry and control link. Before transmission, the data undergoes anti-interference encoding processing to avoid data loss or distortion caused by space electromagnetic interference. The transmission delay is strictly controlled within 500ms to ensure data timeliness. It provides accurate and real-time raw data for gain difference calculation, deviation angle inverse calculation, and actual pointing vector inverse calculation. Through multi-device collaborative acquisition and anti-interference transmission design, it ensures the accuracy and real-time performance of azimuth, elevation, and AGC telemetry information, avoiding correction deviations caused by data errors.

[0046] In a preferred embodiment of the present invention, in the step of gain difference inverse calculation, the gain difference Δ_gain_antenna between the actual signal and the theoretical signal is inversely calculated by using a specific formula based on the real-time uplink signal AGC received from the ground and the EIRP of the signal transmitted by the ground terminal, combined with preset signal transmission parameters, to establish the correlation between signal characteristics and pointing deviation.

[0047] Specifically, the first step is to determine the preset parameters required for the calculation, including the EIRP (P) for transmitting remote control signals along the ground. G The signal spatial loss (L) is obtained from the calibration parameters of the ground terminal equipment, and the unit is dBm; the signal spatial loss is calculated based on the real-time orbital distance between the flat-panel satellite and the ground station and the signal operating frequency, and the unit is dB. Factors such as atmospheric attenuation, rain attenuation, and free-space propagation loss are considered in the calculation; the satellite antenna gain (G) is... A The gain of the satellite transponder (including LNA) accompanying remote control signal (G) is determined by the antenna design parameters, in dB, and this parameter has been calibrated during the ground testing phase. R The value is determined by the transponder hardware parameters, in dB, and has also been verified through ground testing; it is obtained through a pre-calibrated functional relationship P. AGC =f(V) AGC The EIRP (P) signal used in conjunction with AGC is calculated. AGC ), where f( ˙ The function representing the quantitative mapping between AGC voltage and EIRP is obtained through fitting multiple sets of experimental data during the ground testing phase to ensure mapping accuracy. Specifically, P... AGC =f(V AGC )=K1×V AGC ²+K2×V AGC +K3, where: K1, K2, and K3 are fixed constants obtained from the ground experiment fitting; V AGC The average value of the uplink AGC in QV mode of the TM24015 A unit and the uplink AGC in QV mode of the TM24083 B unit is used for telemetry. QV mode is a high-throughput communication mode that coordinates the Q band and V band. The TM24015 A unit and the TM24083 B unit are dual-redundant terminals for collecting uplink AGC telemetry data in QV mode.

[0048] Finally, substitute the above parameters into the formula Δ_gain_antenna=P G -L+G A +G R -P AGCThe gain difference Δ_gain_antenna between the actual and theoretical signals is calculated. This quantifies the signal strength difference into a gain difference, establishing a bridge between signal-level error and antenna pointing deviation, providing a quantitative basis for subsequent deviation angle calculation. Furthermore, through precise parameter calibration and function fitting, the gain difference is accurately calculated, transforming abstract signal errors into quantifiable values ​​and improving the accuracy of error quantification.

[0049] In a preferred embodiment of the present invention, in the accuracy judgment step, by setting a gain error threshold for the pointing requirement of the adaptive point beam antenna, the calculated gain difference Δ_gain_antenna is compared with the threshold to determine whether the current antenna pointing accuracy meets the requirements and to decide whether to start the subsequent correction process.

[0050] Specifically, based on the actual mission requirements of flat-panel satellite point beam communication, such as data transmission rate and communication link stability requirements, a pointing accuracy threshold corresponding to the gain difference is preset. For example, for high code rate communication missions, the threshold is set to ±1dBm. The real-time calculated Δ_gain_antenna is compared with the preset threshold. If Δ_gain_antenna is within the threshold range, the current antenna pointing accuracy is determined to meet the communication requirements, and the correction process stops. If Δ_gain_antenna exceeds the threshold range, the pointing accuracy is determined to be substandard, and subsequent correction steps such as deviation angle back-calculation and vector optimization are initiated. This process serves as a judgment node in the correction process, ensuring the targeting and efficiency of the correction process. Through dynamic threshold judgment, the correction process can be started on demand, reducing satellite resource consumption and improving correction efficiency.

[0051] In a preferred embodiment of the present invention, in the step of back-calculating the deviation angle, by combining the pre-stored antenna directional gain map with the calculated gain difference Δ_gain_antenna, the deviation angle θ between the actual pointing vector of the current satellite to the ground station and the theoretical pointing vector is back-calculated, and the signal gain error is converted into an angle deviation.

[0052] Specifically, a pre-established directional gain map database for a two-dimensional mechanical antenna with a flat-panel satellite point beam is constructed through ground-based anechoic chamber testing. This database contains gain data for the antenna under different azimuth and elevation angle combinations, with data accuracy adapted to pointing deviation correction requirements. The database also supports dynamic updates based on the antenna's on-orbit operating status. Based on the calculated Δ_gain_antenna, the corresponding angular deviation range is searched in the antenna directional gain map database. The calculation results are optimized using linear or polynomial interpolation algorithms to obtain the deviation angle θ between the current actual pointing vector and the theoretical pointing vector, with the inverse calculation accuracy controlled within 0.2°. This transforms signal-level gain error into spatial angular deviation, achieving error type conversion. Furthermore, the combination of the antenna directional gain map and interpolation algorithms enables precise conversion of gain error to angular deviation, solving the problem that signal errors are difficult to directly use for pointing correction.

[0053] In a preferred embodiment of the present invention, in the step of actual pointing vector inverse calculation, based on the collected azimuth and elevation angle information of the antenna pointing to the ground station, the actual pointing vector V_actual_antenna of the current satellite to the ground station is calculated by coordinate system transformation, and the two-dimensional angle information is transformed into a three-dimensional spatial vector.

[0054] The specific implementation process is as follows: First, a three-dimensional spatial coordinate system is established. This coordinate system can be either the flat-panel satellite body coordinate system or the ground station inertial coordinate system, ensuring that the coordinate system is compatible with the positional relationship of the satellite and the ground station. Based on the acquired azimuth and elevation angles, they are converted into three-dimensional spatial vectors using trigonometric function transformation formulas. The three components of the vector correspond to the X, Y, and Z axes of the three-dimensional coordinate system, respectively. During the conversion process, the azimuth and elevation angle data are filtered to eliminate the influence of measurement noise on vector calculation, ensuring the accuracy of the actual pointing vector V_actual_antenna. This achieves the conversion of two-dimensional angle information into three-dimensional spatial vectors, providing vector-level input parameters for subsequent nonlinear optimization solutions using the Gauss-Newton method, thereby improving the dimension of error representation. Through coordinate system transformation and data filtering, accurate conversion from two-dimensional angles to three-dimensional vectors is achieved.

[0055] In a preferred embodiment of the present invention, the Gauss-Newton method optimization solution step uses the deviation angle θ and the actual pointing vector V_actual_antenna as inputs to construct a nonlinear optimization objective function, and uses the Gauss-Newton method to iteratively solve for the optimal theoretical pointing vector V_ideal_antenna, thus transforming the pointing correction problem into a mathematical optimization problem.

[0056] The specific process involves first constructing an optimization objective function, which is set as minimizing the deviation between the actual pointing vector V_actual_antenna and the theoretical pointing vector V_ideal_antenna under the constraint of the deviation angle θ. The Gauss-Newton method is used for iterative solution. In each iteration, the gradient of the objective function and the approximate value of the Hessian matrix are calculated. The iteration step size of the theoretical pointing vector is adjusted according to the gradient direction until the objective function value is less than the convergence threshold, thus obtaining the optimal theoretical pointing vector V_ideal_antenna. A maximum number of iterations is set during the iteration process to avoid convergence failure due to special circumstances. If convergence is not achieved after reaching the maximum number of iterations, an alarm signal is issued and abnormal information is recorded. This transforms the engineering problem of antenna pointing correction into a mathematical nonlinear optimization problem, solving for the optimal theoretical pointing vector using mature numerical methods, providing a target benchmark for installation matrix calculation. By leveraging the fast convergence and high-precision solution capability of the Gauss-Newton method, the optimal solution for the theoretical pointing vector is achieved, ensuring the accuracy of the solution results and improving the overall accuracy of the correction.

[0057] In a preferred embodiment of the present invention, in the step of installing the matrix solution, based on the optimal theoretical pointing vector V_ideal_antenna obtained by the solution, and combined with the mapping relationship between the antenna installation reference coordinate system and the satellite body coordinate system, the installation matrix information matching the theoretical pointing is calculated, and the mathematical optimization result is transformed into engineering-achievable mechanism adjustment parameters.

[0058] The specific process involves first clarifying the relative positional relationship between the antenna installation reference coordinate system and the flat-panel satellite body coordinate system. This relationship, determined through precise measurements during the satellite assembly phase, serves as the benchmark for calculating the installation matrix. Based on the deviation between the optimal theoretical pointing vector V_ideal_antenna and the vector corresponding to the antenna's current actual pointing direction, the required adjustment angles for the antenna in the azimuth, elevation, and roll directions are calculated. Based on these adjustment angles, a 3×3 installation matrix is ​​constructed, with each element corresponding to an adjustment parameter for one direction. The matrix form satisfies the conversion requirements of spatial rotation vectors. The calculated installation matrix is ​​then verified through simulation calculations to confirm whether the antenna pointing direction corresponding to this matrix matches the theoretical pointing vector V_ideal_antenna. If they do not match, the calculation parameters are readjusted until the installation matrix meets the pointing requirements. This process transforms the optimal theoretical pointing vector into an antenna installation matrix, realizing the conversion from mathematical optimization results to engineering adjustment parameters, and providing a concrete basis for adjusting the antenna installation matrix. Furthermore, by using coordinate system mapping and matrix calculation, the abstract vector optimization results are transformed into installation matrix parameters that can be directly used for antenna adjustment, solving the problem that mathematically optimal solutions are difficult to apply directly to engineering practice and ensuring the feasibility of the correction strategy.

[0059] In a preferred embodiment of the present invention, in the steps of installation matrix adjustment and closed-loop feedback, the antenna installation matrix is ​​adjusted according to the calculated installation matrix information, and the above-mentioned steps of data acquisition, gain difference calculation, and accuracy judgment are repeated to form a closed-loop feedback correction process until the gain difference meets the pointing accuracy requirements.

[0060] The specific implementation process involves injecting the calculated installation matrix into the satellite antenna controller via a flat-panel satellite telemetry and control link. The antenna controller, based on the adjustment parameters in the installation matrix, controls the antenna's two-dimensional rotation mechanism to make corresponding adjustments in azimuth, elevation, and roll directions. After the installation matrix adjustment is complete, the system returns to collect the azimuth, elevation, and AGC telemetry information pointing the antenna to the ground station, repeating the steps of gain difference back calculation, accuracy judgment, deviation angle back calculation, vector optimization, and installation matrix calculation and adjustment. After each closed-loop iteration, the difference between the current gain difference and a preset threshold is compared to determine the correction effect. If the gain difference meets the accuracy requirements, the correction process stops, and the current installation matrix parameters are saved as the reference for subsequent antenna pointing. If not, iterative correction continues until the requirements are met or the preset maximum number of iterations is reached. This closed-loop feedback mechanism dynamically adjusts the antenna installation matrix, continuously optimizing pointing accuracy to ensure the final antenna pointing meets accuracy requirements, while also enabling self-verification and adjustment of the correction process. The closed-loop feedback design ensures the continuity and accuracy of the correction process, dynamically compensates for real-time errors during satellite operation, avoids the problem that a single correction cannot completely eliminate the deviation, and ultimately achieves stable compliance with antenna pointing accuracy.

[0061] In this invention, it should be noted that the azimuth and elevation angles provided in the on-orbit real-time data acquisition stage provide the basis for the relative position of the satellite and the ground station in calculating the signal spatial loss (L). The AGC telemetry information is directly used as P. AGC The input for the calculation is the gain difference; however, the gain difference inverse calculation depends on the accurate parameters provided by the data acquisition stage. If there are errors in the data acquisition, it will directly lead to deviations in the gain difference calculation. This forms a close collaborative relationship between data input and quantization output. The accuracy of data acquisition determines the accuracy of the gain difference inverse calculation, and the result of the gain difference inverse calculation provides a basis for subsequent accuracy judgment, together forming the basic link of error quantization.

[0062] In this invention, the deviation angle θ, calculated by back-calculation, reflects the difference between the actual and theoretical pointing angles. The actual pointing vector V_actual_antenna, calculated by back-calculation, clarifies the current spatial position of the pointing vector and serves as the input for the Gauss-Newton method optimization solution. If the deviation angle θ is missing, the angle constraint between the actual and theoretical vectors cannot be determined. If the actual pointing vector V_actual_antenna is missing, the starting benchmark for optimization cannot be determined. Only when both are input together can a complete nonlinear optimization model be constructed and the accurate solution of the theoretical pointing vector be achieved.

[0063] In this invention, the optimal theoretical pointing vector V_ideal_antenna obtained by the Gauss-Newton method is the target reference for the installation matrix calculation. The installation matrix calculation needs to determine the adjustment parameters based on the deviation between V_ideal_antenna and the current actual pointing. If there is a deviation in the V_ideal_antenna solution, the installation matrix calculation will use the incorrect target as the reference, resulting in a deviation in the correction direction. At the same time, the accuracy of the installation matrix calculation affects the actual implementation effect of V_ideal_antenna. Only in this way can the mathematically optimal solution be transformed into accurate engineering adjustment parameters, forming a synergistic transformation relationship between theoretical target and engineering implementation.

[0064] In this invention, a closed-loop feedback mechanism runs through the entire process of data acquisition, gain difference back calculation, accuracy judgment, deviation angle back calculation, vector optimization, and installation matrix solution and adjustment. After each installation matrix adjustment, the real-time status is reacquired through data acquisition, and the correction effect is verified through gain difference back calculation and accuracy judgment. If the target is not met, the deviation angle back calculation, vector optimization, and other steps are restarted to dynamically adjust the correction strategy. The output results of each step provide a basis for judgment for the closed-loop feedback, and the results of the closed-loop feedback guide the re-execution of each step, forming a virtuous cycle of acquisition-calculation-adjustment-verification-re-adjustment, ensuring that each step works together to improve the correction accuracy.

[0065] Meanwhile, the on-orbit pointing deviation correction method for a two-dimensional mechanical antenna with a point beam for a flat-panel satellite proposed in this invention is also applicable to the on-orbit pointing correction of a large-size phased array antenna in the scenario of direct satellite connection between a tablet and a mobile phone.

[0066] Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art, all of which fall within the protection scope of this invention.

Claims

1. A method for correcting the pointing deviation of a two-dimensional mechanical antenna with a point beam for flat-panel satellites, characterized in that, Includes the following steps: Step S1: In real time on orbit, acquire the azimuth angle, elevation angle, and uplink signal power detection information of the antenna pointing to the ground station; Step S2: Based on the real-time uplink signal power detection information received from the ground and the EIRP of the signal transmitted by the ground terminal, calculate the gain difference Δ_gain_antenna between the actual signal and the theoretical signal. The expression for calculating the gain difference Δ_gain_antenna is: Δ_gain_antenna = P G -L+G A +G R -P AGC ; Among them, P G EIRP for transmitting remote control signals along the ground; L is the signal spatial loss; G A For satellite antenna gain; G R For the satellite transponder's accompanying remote control signal gain; P AGC For the EIRP of the in-path remote control signal calculated using AGC, the P AGC Through the functional relationship P AGC =f(V) AGC The calculation yields f, where f is V. AGC With P AGC The quantitative mapping function between them, specifically P AGC =f(V AGC )=K1×V AGC ²+K2×V AGC +K3, where: K1, K2, and K3 are fixed constants obtained from the ground experiment fitting; V AGC The average value of the uplink AGC in QV mode of the TM24015 A unit and the uplink AGC in QV mode of the TM24083 B unit is used for telemetry. QV mode is a high-throughput communication mode that coordinates the Q band and V band. The TM24015 A unit and the TM24083 B unit are dual-redundant terminals for collecting uplink AGC telemetry data in QV mode. Step S3: Determine whether the gain difference Δ_gain_antenna meets the pointing accuracy requirements. If it does, stop the correction; otherwise, proceed with the next steps. Step S4: Based on the antenna directional gain diagram and the gain difference Δ_gain_antenna, calculate the deviation angle θ between the actual pointing vector of the current satellite to the ground station and the theoretical pointing vector; Step S5: Based on the azimuth and elevation angle information, calculate the actual pointing vector V_actual_antenna of the current satellite to the ground station; Step S6: Based on the deviation angle θ and the actual pointing vector V_actual_antenna, the problem is transformed into a nonlinear problem. The optimal theoretical pointing vector V_ideal_antenna is solved by using the Gauss-Newton method. When using the Gauss-Newton method, the objective function is to minimize the deviation between the actual pointing vector and the theoretical pointing vector. The optimal solution is obtained through iterative convergence. Step S7: Based on the theoretical pointing vector V_ideal_antenna and the installation matrix preset before antenna transmission, calculate the installation matrix information that matches the theoretical pointing. The calculation of the installation matrix information is based on the mapping relationship between the theoretical pointing vector V_ideal_antenna and the antenna installation reference coordinate system. Step S8: Adjust the antenna mounting matrix according to the mounting matrix information, then return to step S1 and repeat until the gain difference Δ_gain_antenna meets the pointing accuracy requirements.

2. The method according to claim 1, characterized in that, The pointing accuracy requirement mentioned in step S3 is the gain error threshold corresponding to the spot beam antenna, and the gain error threshold is preset according to the requirements of the satellite communication mission.

3. The method according to claim 1, characterized in that, In step S4, when calculating the deviation angle θ, a pre-stored antenna directional gain map database is called, which contains antenna gain data at different pointing angles.

4. The method according to claim 1, characterized in that, In step S5, during the inverse calculation of the actual pointing vector V_actual_antenna, the azimuth and elevation angles are converted into vector representations in a three-dimensional spatial coordinate system.

5. The method according to claim 1, characterized in that, The azimuth and elevation angles are collected in real time by an angle sensor integrated into the antenna's two-dimensional rotation mechanism. The raw data of the azimuth and elevation angles pointing from the antenna to the ground station are collected in real time. The uplink signal power detection information is transmitted to the ground station in real time through the satellite telemetry and control link.

6. The method according to claim 1, characterized in that, Suitable for on-orbit pointing correction of phased array antennas for direct connection to satellites for tablets and mobile phones.

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