Space target space-based microwave imaging system design method and device

Abstract

The application relates to the technical field of space imaging, and provides a space target space-based microwave imaging system design method and device. The method firstly determines the intersection course of an observation satellite and a space target based on an orbit dynamics simulation method, and then determines an imaging observation window; then, the relative motion characteristics of the observation satellite and the space target in the imaging observation window and the maximum scanning capability of a phased array antenna are combined to determine a beam scanning geometry and generate a beam scanning strategy; next, precise acquisition and locking of the beam are realized by optimizing the orbit prediction error of the space target; finally, high-precision imaging of the space target is realized by combining a synthetic aperture imaging algorithm and error compensation according to the beam scanning strategy and the optimized orbit parameters of the space target, double high-speed motion imaging feasible position determination is realized, a stable and efficient phased array beam scanning strategy is constructed, high-precision beam pointing of a non-cooperative target is realized, and the precision and reliability of space target imaging are improved.

Description

Technical Field

[0001] This application relates to the field of space imaging technology, and in particular to a design method and device for a space-based microwave imaging system for space targets. Background Technology

[0002] Precise imaging and monitoring of space targets has become a core requirement for ensuring the safe operation of spacecraft and responding to the threat of space debris. Space targets encompass various space objects, including on-orbit spacecraft and space debris, and their imaging quality directly determines the accuracy of target identification, status assessment, and threat prediction. Among numerous observation methods, Synthetic Aperture Radar (SAR) and Inverse Synthetic Aperture Radar (ISAR) have become the preferred technologies for space-based target imaging due to their unique advantages of being available in all weather conditions and unaffected by lighting or meteorological conditions.

[0003] Current space target imaging technologies are mainly divided into two major directions: ground-based imaging and space-based imaging. Although ground-based ISAR is mature, it is limited by the curvature of the Earth, atmospheric attenuation, and geographical range, making it difficult to achieve flexible and full-coverage observation of space targets worldwide. In contrast, space-based SAR or ISAR can overcome the inherent limitations of ground observation, achieving wider-range and more flexible detection and imaging through the flexible deployment of satellite platforms. China has made significant breakthroughs in the field of spaceborne SAR technology. For example, the X-band spaceborne phased array SAR payload has achieved 0.5-meter-level resolution and kept its weight under 100 kilograms, demonstrating excellent on-orbit performance and being widely used in ground target imaging. The Ka-band SAR payload of the Luojia-2 01 satellite developed by the 23rd Research Institute of CASIC, as the world's first spaceborne Ka-band high-resolution SAR payload, has achieved a lightweight and compact design with 0.5-meter-level resolution. Its multi-mode adaptability provides frequency band selection and system design references for the dynamic observation of space targets. The SAR microwave visual three-dimensional imaging theory can significantly reduce the amount of data acquisition for three-dimensional imaging and improve imaging accuracy, and has been used in airborne ground processing systems.

[0004] Internationally, many countries and regions are also actively conducting research on space-based radar imaging technology, such as the Space Based Radar (SBR) program, which aims to achieve real-time monitoring and high-resolution imaging of space targets by optimizing radar operating frequency, bandwidth and other parameters. Other regions focus on the compatibility and multi-functionality of radar systems, and adopt reconfigurable antenna designs to adapt to different observation tasks.

[0005] However, the relevant space-based radar space target imaging technology still has technical defects such as the lack of feasible location determination methods in dual high-speed motion scenarios, unclear phased array beam scanning strategies in high-speed relative motion, and the lack of a precise beam pointing mechanism for non-cooperative targets. Summary of the Invention

[0006] In view of this, embodiments of this application provide a design method and apparatus for a space-based microwave imaging system for space targets, in order to solve the problems in the prior art such as the lack of a feasible location determination method for imaging in dual high-speed motion scenarios, the unclear phased array beam scanning strategy under high-speed relative motion, and the lack of a precise beam pointing mechanism for non-cooperative targets.

[0007] A first aspect of this application provides a method for designing a space-based microwave imaging system for space targets, comprising:

[0008] The rendezvous process between the observation satellite and the space target is determined based on orbital dynamics simulation methods, thereby determining the imaging observation window;

[0009] The beam scanning geometry is determined by combining the relative motion characteristics of the observed satellite and the space target in the imaging observation window with the maximum scanning capability of the phased array antenna, and a beam scanning strategy adapted to the high-speed relative motion of the observed satellite and the space target is generated.

[0010] The beam broadening acquisition, angle measurement and ranging, orbit optimization and narrow beam imaging are executed sequentially to optimize the orbit prediction error of space targets and achieve accurate beam acquisition and locking.

[0011] Based on the beam scanning strategy and the optimized orbital parameters of the space target, high-precision imaging of the space target is achieved by combining the synthetic aperture imaging algorithm with error compensation.

[0012] A second aspect of this application provides a space-based microwave imaging system design device for space targets, comprising:

[0013] The simulation module is configured to determine the rendezvous process between the observation satellite and the space target based on orbital dynamics simulation methods, and then determine the imaging observation window;

[0014] The scanning strategy determination module is configured to determine the beam scanning geometry by combining the relative motion characteristics of the observed satellite and the space target in the imaging observation window and the maximum scanning capability of the phased array antenna, and generate a beam scanning strategy adapted to the high-speed relative motion of the observed satellite and the space target.

[0015] The imaging module is configured to sequentially perform beam widening acquisition, angle measurement and ranging, orbit optimization and narrow beam imaging to optimize the orbit prediction error of space targets and achieve accurate beam acquisition and locking.

[0016] The compensation module is configured to achieve high-precision imaging of space targets by combining synthetic aperture imaging algorithms with error compensation, based on beam scanning strategies and optimized orbital parameters of the space targets.

[0017] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0018] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0019] The beneficial effects of the embodiments in this application compared with the prior art are:

[0020] This application first determines the rendezvous process between the observation satellite and the space target based on orbital dynamics simulation, thereby determining the imaging observation window. Then, combining the relative motion characteristics of the observation satellite and the space target within the imaging observation window with the maximum scanning capability of the phased array antenna, the beam scanning geometry is determined, and a beam scanning strategy adapted to the high-speed relative motion of the observation satellite and the space target is generated. Next, beam broadening acquisition, angle and distance measurement, orbit optimization, and narrow beam imaging are executed sequentially to optimize the orbit prediction error of the space target and achieve accurate beam acquisition and locking. Finally, based on the beam scanning strategy and the optimized orbit parameters of the space target, combined with synthetic aperture imaging algorithm and error compensation, high-precision imaging of the space target is achieved. This enables the determination of feasible positions for dual high-speed motion imaging, constructs a stable and efficient phased array beam scanning strategy, realizes high-precision beam pointing for non-cooperative targets, and improves the accuracy and reliability of space target imaging. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic flowchart of a space target space-based microwave imaging system design method provided in an embodiment of this application.

[0023] Figure 2 This is a schematic diagram of the method for determining a beam scanning strategy provided in an embodiment of this application.

[0024] Figure 3 This is a schematic diagram of the space-based microwave imaging process of a space target.

[0025] Figure 4 This is a schematic diagram of a space target space-based microwave imaging system design device provided in an embodiment of this application.

[0026] Figure 5 This is a schematic diagram of the electronic device provided in the embodiments of this application. Detailed Implementation

[0027] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0028] The following will describe in detail, with reference to the accompanying drawings, a method and apparatus for designing a space-based microwave imaging system for a space target according to an embodiment of this application.

[0029] As mentioned above, the relevant space-based radar space target imaging technology still suffers from several technical defects, including the lack of a feasible location determination method in dual high-speed motion scenarios, unclear phased array beam scanning strategies under high-speed relative motion, and the lack of a precise beam pointing mechanism for non-cooperative targets. These defects are detailed below:

[0030] Existing space-based radar payloads are mostly designed for static or low-speed ground targets and are not specifically adapted to the dual high-speed motion characteristics of space-based radar and space targets. The current technological system lacks a theoretical method to define the feasible imaging range for both, failing to clearly define the relative positional boundaries for effective imaging of the radar and target under complex orbital motions, and also lacking quantitative criteria for key state parameters such as relative velocity and attitude angle required for imaging. This makes it difficult for space-based radars to predict the effective observation window for space targets.

[0031] Synthetic aperture imaging demands extremely high stability for continuous beam tracking of targets. However, the extremely high relative speeds between space-based radar and space targets mean that beam tracking requirements cannot be met solely through satellite attitude adjustments. Although phased array antennas have become the preferred solution for high-speed tracking, current technologies have not established beam scanning methods suitable for this scenario.

[0032] Space targets are primarily non-cooperative, and their precise orbital data is unknown, fundamentally different from the predictable orbital characteristics of cooperative targets. Existing beam pointing technologies rely on prior orbital information for pre-aiming. However, for non-cooperative targets without orbital data, there is a lack of effective beam acquisition and locking closed-loop control mechanisms, making it difficult for the imaging beam to accurately align with the target and severely affecting the signal-to-noise ratio of the imaging signal.

[0033] In view of this, the embodiments of this application provide a design method for a space-based microwave imaging system for space targets. By integrating orbital dynamics analysis, phased array beam scanning optimization, non-cooperative target detection and orbit optimization technologies, a full-link imaging system adapted to dual high-speed motion scenarios is constructed, solving the core problems in the prior art such as difficulty in determining feasible imaging locations, ambiguity in beam scanning strategies, and inaccurate pointing of non-cooperative targets.

[0034] Figure 1 This is a flowchart illustrating a space-based microwave imaging system design method for space targets provided in an embodiment of this application. Figure 1 As shown, the method includes the following steps:

[0035] In step S101, the rendezvous process between the observation satellite and the space target is determined based on the orbital dynamics simulation method, and then the imaging observation window is determined.

[0036] In step S102, the beam scanning geometry is determined by combining the relative motion characteristics of the observed satellite and the space target in the imaging observation window and the maximum scanning capability of the phased array antenna, and a beam scanning strategy adapted to the high-speed relative motion of the observed satellite and the space target is generated.

[0037] In step S103, beam widening acquisition, angle measurement and ranging, orbit optimization and narrow beam imaging are performed sequentially to optimize the orbit prediction error of the space target and achieve accurate beam acquisition and locking.

[0038] In step S104, high-precision imaging of the space target is achieved by combining the synthetic aperture imaging algorithm with error compensation, based on the beam scanning strategy and the optimized orbital parameters of the space target.

[0039] In some embodiments of this application, the method may be executed by a server or by a terminal device with certain processing capabilities.

[0040] In some embodiments of this application, the rendezvous process between the observation satellite and the space target can first be determined based on orbital dynamics simulation methods, thereby determining the imaging observation window. Then, the beam scanning geometry is determined by combining the relative motion characteristics of the observation satellite and the space target within the imaging observation window with the maximum scanning capability of the phased array antenna, and a beam scanning strategy adapted to the high-speed relative motion between the observation satellite and the space target is generated.

[0041] The relative motion characteristics of the observed satellite and the space target in the imaging observation window can include the velocity of the observed satellite, the velocity of the space target, and the orbital angle between the observed satellite and the space target in the imaging observation window.

[0042] In some embodiments of this application, beam broadening and acquisition, angle and distance measurement, orbit optimization, and narrow beam imaging can be performed sequentially to optimize the orbit prediction error of the space target and achieve accurate beam acquisition and locking. Finally, based on the beam scanning strategy and the optimized orbit parameters of the space target, high-precision imaging of the space target is achieved by combining a synthetic aperture imaging algorithm with error compensation.

[0043] According to the technical solution provided in this application, the intersection process between the observation satellite and the space target is first determined based on the orbital dynamics simulation method, and then the imaging observation window is determined. Then, the beam scanning geometry is determined by combining the relative motion characteristics of the observation satellite and the space target in the imaging observation window and the maximum scanning capability of the phased array antenna, and a beam scanning strategy adapted to the high-speed relative motion of the observation satellite and the space target is generated. Next, beam broadening acquisition, angle measurement and ranging, orbit optimization and narrow beam imaging are executed in sequence to optimize the orbit prediction error of the space target and achieve accurate beam acquisition and locking. Finally, based on the beam scanning strategy and the optimized orbit parameters of the space target, high-precision imaging of the space target is achieved by combining the synthetic aperture imaging algorithm and error compensation. This enables the determination of feasible positions for dual high-speed motion imaging, constructs a stable and efficient phased array beam scanning strategy, realizes high-precision beam pointing of non-cooperative targets, and improves the accuracy and reliability of space target imaging.

[0044] In some embodiments of this application, determining the rendezvous process between an observation satellite and a space target based on orbital dynamics simulation may include: first, using an orbital dynamics simulation platform to build a space-based microwave imaging simulation scenario of the space target; setting the scenario time period; initializing the orbital epochs and orbital parameters of the observation satellite and the space target; and obtaining the radar payload parameters of the observation satellite. The radar payload parameters include at least the radar wavelength. Imaging distance and azimuth resolution .

[0045] Then, using the radar equations as range constraints, the predicted distance between the observed satellite and the space target is determined based on orbital dynamics simulation. The satellite trajectories and space target trajectories when the predicted distance is less than a preset distance threshold are identified as candidate intersection segments, thereby determining the duration of the intersection between the observed satellite and the space target. and minimum distance .

[0046] Next, we determine the angular velocity of the observation satellite pointing towards the space target as: Determine the angular velocity The smallest intersection segment is the target imaging range. Simultaneously, the radar's synthetic aperture length is determined to be... Based on this, the maximum imaging distance was determined to be... And within the target imaging range, the observation window is determined based on the maximum imaging distance; where, To find the minimum value function, This represents the azimuth scanning angle of the radar antenna.

[0047] In other words, a space-based microwave imaging simulation scenario for space targets can be built using an orbital dynamics simulation platform. The orbital parameters of the observation satellite and the space target can be input into this platform to calculate their intersection history, thereby defining feasible imaging locations and observation windows. The orbital parameters can be the six fundamental orbital parameters, including the semi-major axis, eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee, and true anomaly of both the observation satellite and the space target.

[0048] When establishing a space simulation scenario, the time period of the scenario can be set first, which should cover the duration required for orbit prediction. Then, the orbital epochs and orbital parameters of the observation satellite and space target are initialized. Simultaneously, the core payload parameters of the radar carried by the observation satellite, including carrier frequency, are obtained. ,wavelength Antenna dimensions (including range dimensions) and azimuth dimension ), 3dB beamwidth (including azimuth) and distance Imaging resolution requirements (e.g., azimuth resolution) Detection range and imaging distance .

[0049] Then, the rendezvous process is calculated and filtered. Radar equations can be used as range constraints, and the distance between the space target and the observation satellite is obtained through orbital dynamics simulation. When the distance is less than the range constraint of the radar equations, it is considered an interaction between the observation satellite and the space target, thus obtaining the rendezvous start time, end time, and duration of the observation satellite and the space target. and minimum distance Parameters such as these.

[0050] The optimal intersection segment can be selected as the target intersection segment using the "minimum angular velocity principle". In some implementations, the angular velocity of the observed satellite pointing towards the space target can be calculated. The intersection segment with the minimum angular velocity is selected as the target intersection segment, which can be set as the imaging core region to reduce the difficulty of beam tracking. At the same time, invalid intersection trajectories with a minimum distance exceeding the imaging distance threshold can be eliminated.

[0051] Simultaneously, feasible location boundaries can be defined: based on the principle of synthetic aperture imaging, the synthetic aperture length is calculated in combination with resolution requirements. Finally, the azimuth scanning angle of the radar antenna is combined. Constraints are used to determine the maximum imaging distance. Define the feasible distance range for imaging to ensure that space targets meet high-resolution imaging requirements within this range.

[0052] In some embodiments of this application, determining the beam scanning geometry by combining the relative motion characteristics of the satellite and the space target observed in the imaging observation window with the maximum scanning capability of the phased array antenna may include, based on the space target velocity... Observing satellite speed and the orbital angle between the observation satellite and the space target Determine the angle of the scanning plane as Then, the scanning plane is determined in the inertial coordinate system; the attitude of the observation satellite is adjusted so that the maximum scanning capability plane of the phased array antenna coincides with the scanning plane; based on the maximum scanning angle of the phased array antenna and the phased array antenna after attitude adjustment, the unique scanning plane and the beam allowable coverage area are determined, and then the beam scanning geometry is determined.

[0053] Based on this, the beam scanning strategy can be determined as follows: obtain the azimuth projection velocity of the space target within the beam scanning geometry. According to the formula Determine the real-time azimuth angle of a space target within the beam scanning geometry. ;in, The initial azimuth angle, For a moment The slant range between the observation satellite and the space target. For a moment Azimuth projection velocity; obtain the pitch projection velocity of a space target within the beam scanning geometry. According to the formula Determine the real-time elevation angle of a space target within the beam scanning geometry. ;in, The initial pitch angle, For a moment The pitch projection velocity; and the time series fitting model of the real-time azimuth angle are constructed respectively. Time series fitting model of real-time pitch angle The beam scanning pattern of the phased array antenna is obtained; among which, Radar power-on duration, is the fitting coefficient, and n is a positive integer.

[0054] Furthermore, the azimuth angular velocity of the space target within the beam scanning geometry can also be determined as follows: , This allows us to determine the time it takes for a space target to pass through the antenna's main lobe once. ;in, The azimuth beamwidth is 3dB. For beamwidth factor, To observe the slant range between the satellite and the space target; to obtain the orbit prediction error of the space target; and to determine the projection of the orbit prediction error into the beam scanning geometry. ;based on and The detection start-up and shutdown lead time is determined to be ;in, This refers to the azimuth coverage area of ​​the radar beam. This is used to ensure that the lead time for the probe's on / off is sufficient to compensate for the deviation in the spatial target's position caused by orbit prediction errors.

[0055] Figure 2 This is a schematic diagram of the method for determining a beam scanning strategy provided in an embodiment of this application. Figure 2 The line of sight is perpendicular to the velocity from point O. and speed Looking downwards, point O represents the predicted intersection point between the observed satellite and the space target. The method for determining the beam scanning strategy is shown within the dashed box on the right.

[0056] Since both the observation satellite and the space target are high-speed moving objects, the intersection time is very short, on the order of 2-7 seconds. The two objects can be equivalent to uniform linear motion in space. The position of the maximum scanning capability plane of the antenna in space is determined by the orbits of the observation satellite, the space target, and the maximum scanning angle of the phased array antenna.

[0057] refer to Figure 2 The orbital angle between the observation satellite and the space target It can be determined by the six base numbers of the orbits of both, and further, it can be combined with... and , Determine the angle of the scanning plane This allows for the determination of the scanning plane in the inertial coordinate system. Among these, .

[0058] Next, the observation satellite can adjust its attitude to align the maximum scanning capability plane of the phased array antenna with a defined scanning plane. The maximum scanning capability plane of the phased array antenna is defined in the antenna coordinate system. Simultaneously, the deflectable range can be determined by the maximum scanning angle of the phased array antenna. Superimposing the attitude-adjusted phased array antenna with its deflectable range forms a unique scanning plane and the allowed beam coverage area, thus constructing a beam scanning geometry adapted to high-speed targets.

[0059] Once the beam scanning geometry is determined, the real-time projection position of the spatial target in the scanning plane can be calculated based on the uniquely determined beam scanning geometry, and the azimuth angle can be established. With pitch angle The dynamic variation model over time. Considering system design constraints and beam tracking smoothness, 3rd to 5th order polynomials can be used to fit the model respectively. and The time series is used to obtain the beam scanning strategy of the phased array antenna.

[0060] Simultaneously, a dynamic adjustment strategy for the phased array antenna beam scanning parameters can be set. In some implementations, the time it takes for the target to pass through the antenna main lobe once can be calculated based on the azimuth angular velocity of the space target in the scanning plane. Combined with the projection of the space target's trajectory prediction error into the beam scanning geometry, the detection on / off lead can be determined, thereby determining the dynamic adjustment strategy for the scanning parameters. This ensures continuous beam coverage of the target by dynamically adjusting the scanning parameters.

[0061] In some embodiments of this application, the precise acquisition and locking of the beam is achieved in the following manner:

[0062] First, adjust the radar beam according to the widening factor. Broadening, to obtain the broadened azimuth beamwidth. and the widened range beamwidth ,in, The range is 3dB beamwidth.

[0063] Then based on and The initial detection of the space target will be conducted to obtain its initial location; the initial location will include at least the distance between the observation satellite and the space target. Azimuth Pitch angle .

[0064] The initial point can be transformed from the antenna coordinate system to the inertial system. The initial coordinates of the space target in the inertial system can be determined by combining the orbital position and attitude parameters of the observed satellite in the inertial system. The initial coordinates can be optimized to obtain the optimized orbital coordinates. The total positional error between the optimized orbital coordinates and the initial point is less than a preset threshold.

[0065] Next, based on the optimized orbital coordinates, the radar is switched to narrow beam mode, and the target in space is locked by updating the beam pointing; the beam width of the narrow beam is the original 3dB beam width of the radar.

[0066] Finally, a closed-loop beam pointing control system is constructed, iteratively executing the steps of acquiring real-time detection points, optimizing the trajectory using real-time detection points, switching the radar to a narrow beam mode based on the optimized trajectory coordinates, and locking onto the space target by updating the beam pointing, to ensure that the beam center is always aligned with the space target during the imaging phase; wherein, the beam pointing includes real-time azimuth angle. and real-time pitch angle .

[0067] The use of real-time detection points for orbit optimization can include: predicting the original orbit based on the spatial target, limiting the optimization range of the six orbital elements; and determining the objective function as follows: ;in, To optimize the orbit at time The position vector, To detect the trace at time The position vector, To detect the number of dots, The L2 norm squared is used to optimize the orbital parameters of the space target using a numerical optimization algorithm, resulting in optimized orbital coordinates.

[0068] The closed-loop control error formula can be , This is the closed-loop control error. The beam pointing command angle, For actual feedback angle, This is the pointing error threshold.

[0069] Figure 3 This is a schematic diagram of the space-based microwave imaging process of a space target. Figure 3 The upper center displays the orbit of the space target, including its actual and predicted orbits. The lower center displays the orbit of the observation satellite and the operating mode of the radar carried by the observation satellite. Both the observation satellite and the space target move from left to right.

[0070] like Figure 3 As shown, the observation satellite can first activate the radar's wait-and-track mode. In this mode, the radar beam is widened, transmitting across the entire array and receiving data from all four subarrays to track the space target. Orbit corrections can be made during tracking. If the imaging conditions for the space target are met, the radar's imaging mode can be activated. In this mode, the radar beam narrows, transmitting and receiving data from the entire array until imaging is complete. When the space target is non-cooperative, the observation satellite cannot obtain accurate orbit predictions. Therefore, by sequentially executing beam widening acquisition, angle and distance measurement, orbit optimization, and narrow beam imaging, the orbit prediction error of the space target can be optimized, thereby achieving accurate beam acquisition and locking.

[0071] In particular, when widening the beam, considering the unknown trajectory of non-cooperative targets, the radar beam can be widened by a factor of [missing information]. Widening the beam increases the coverage area and improves the probability of target acquisition. Then, the widened beam can be used for initial target detection to determine the target's distance. Azimuth Pitch angle Based on basic point information, angle and distance measurements are completed. Among these, the azimuth angle... and pitch angle The measurement accuracy is determined by both beamwidth and signal-to-noise ratio, and distance. The measurement accuracy is determined by the radar bandwidth. Decide.

[0072] In some implementations, the angle measurement step can also be achieved by methods such as amplitude comparison angle measurement or phase comparison angle measurement, depending on the performance and design of the radar antenna.

[0073] Next, orbit optimization is performed. The probe track can be transformed from the antenna coordinate system to the inertial coordinate system. Combined with the orbital position and attitude parameters of the observed satellite in the inertial frame, the initial coordinates of the space target in the inertial frame are obtained. Then, based on the predicted initial orbit of the space target, the orbit is limited to six elements (semi-major axis). Right ascension of ascending node True near point angle To avoid deviating from physical constraints, a numerical optimization algorithm is used to optimize the orbital parameters. The objective function can be "minimizing the sum of the positional errors between the optimized orbit and the probe track," meaning the corrected orbital prediction error must meet the requirement that "the sum of the three-axis (radial, tangential, and lateral) errors is less than the beam coverage area."

[0074] In some implementations, orbit optimization for non-cooperative targets can be achieved through multiple probes, and the probe strategy can be adjusted based on target priority. For example, when the orbital error of a space target is small, or when the orbital error of a space target is large but its priority is low, a simplified strategy of "one broadened probe + real-time orbit correction + one narrow-beam imaging" can be used; when the target's orbital error is large, or when the orbital error of a space target is small but its priority is high, a strategy of "multiple broadened probes + real-time orbit correction + one narrow-beam imaging" can be used, or a strategy of "multiple broadened probes + real-time orbit correction + multiple narrow-beam imagings alternating" can be used; beam broadening factor The system can be dynamically adjusted based on the magnitude of the orbital error (the larger the error, the greater the magnification factor) to balance the acquisition probability and detection accuracy. For cooperative targets, with known high-precision orbital data, the detection mode can be omitted, and the system can directly enter imaging mode.

[0075] Finally, narrow beam switching and precise pointing lock are performed to achieve narrow beam imaging. In some implementations, based on the corrected target satellite orbit parameters, the system can switch to narrow beam (imaging beam) mode, with the narrow beam width being the radar's original 3dB beam width. This is achieved by real-time updates of the beam pointing command (azimuth angle). Pitch angle This enables precise beam locking onto non-cooperative targets. Simultaneously, a closed-loop beam pointing control system is constructed. By repeatedly feeding back detection points and trajectory correction results—that is, by repeatedly activating detection mode or alternating between detection and imaging modes—the beam pointing is dynamically adjusted to ensure that the beam center remains aligned with the target throughout the imaging phase.

[0076] In some embodiments of this application, achieving high-precision imaging of a space target by combining a synthetic aperture imaging algorithm with error compensation, based on a beam scanning strategy and optimized orbital parameters of the space target, may include: determining the relative motion velocity of the target satellite and the observation satellite in the equatorial coordinate system during the imaging time period; performing translational motion compensation on the radar echo data based on the relative motion velocity; performing Doppler parameter optimization and refined imaging compensation on the radar echo data after translational motion compensation to eliminate the first-order range migration; converting the platform position error, payload electronic device error, antenna pattern error of the observation satellite, and orbit prediction error of the space target into phase perturbations or amplitude perturbations of the radar echo data, respectively, and then using the converted phase perturbations or amplitude perturbations to perform error compensation on the radar echo data after Doppler parameter optimization and refined imaging compensation.

[0077] In other words, a defined beam scanning strategy and optimized orbit prediction error can be integrated with aperture imaging algorithms and end-to-end error compensation technology to achieve high-precision imaging of space targets.

[0078] On the one hand, it can compensate for translational motion. For example, it can be done based on the three-dimensional coordinates of the target satellite and the observation satellite in the equatorial coordinate system during the imaging time period. , Calculate the relative velocity between the two. Translational motion compensation is performed on radar echo data to eliminate imaging blur caused by relative motion.

[0079] Compensated echo phase The formula is ;in, This represents the original echo phase.

[0080] On the other hand, it allows for Doppler parameter optimization and refined imaging. For example, wedge transform processing can be applied to the compensated signal to eliminate first-order range migration, and the wedge transform kernel function... for ,in, For distance to fast time, For range frequency, For range-directed frequency modulation, The center frequency.

[0081] By sequentially performing time interception, highlight point extraction, Doppler parameter estimation, and spatial distribution fitting, the spatial distribution of the target's Doppler parameters can be obtained. Then, based on this distribution, the image domain is divided into regions, and fine motion compensation is performed on the data of each sub-region to obtain spatial target imaging results with imaging resolution meeting preset requirements (such as better than 3 cm).

[0082] In some implementations, imaging algorithms such as the range Doppler algorithm or the back projection algorithm can be used to replace the wedge transformation described above.

[0083] It can also perform end-to-end error compensation. In some real-time methods, it can comprehensively compensate for platform position errors. Target star orbit prediction error Errors in load electronic components Antenna pattern error By modeling errors, various errors are transformed into phase or amplitude disturbances in radar echo data, and the effects of these errors are offset in real time during the imaging process.

[0084] Position error compensation can be performed in the following ways: , This is the position error compensation value. The vector is a radial unit vector; electronic device error compensation can be performed in the following ways: , This refers to the error compensation value for electronic components; antenna pattern error compensation can be performed in the following ways: , This is the antenna pattern error compensation value. This represents the original antenna gain.

[0085] The technical solution provided in this application fills the gap in determining the feasible location for imaging of two high-speed moving targets. By using orbital dynamics simulation and convergence process analysis, combined with the resolution requirements of synthetic aperture imaging, a quantitative standard for determining the feasible location for imaging is established. This solves the problem of difficulty in predicting the observation window under the dual high-speed motion of space-based radar and space targets, and provides a scientific basis for imaging mission planning.

[0086] The technical solution provided in this application constructs a stable and efficient phased array beam scanning strategy. Based on beam scanning law modeling, dynamic adjustment of beam parameters under high-speed relative motion is realized, ensuring continuous and stable beam tracking of high-speed targets.

[0087] The technical solution provided in this application embodiment achieves high-precision beam pointing for non-cooperative targets. Through a closed-loop mechanism of "beam broadening acquisition - angle measurement and ranging - orbit correction - narrow beam imaging", the corrected space target orbit prediction error meets the imaging beam coverage requirements, effectively solving the problem of inaccurate beam pointing caused by unknown orbits of non-cooperative targets.

[0088] The technical solution provided in this application improves the accuracy and reliability of space target imaging. It integrates end-to-end error compensation technology, covering multi-dimensional compensation for orbital errors, payload errors, and attitude errors, meeting the needs for refined space target identification. Simultaneously, the dynamic detection strategy and parameter adjustment mechanism enhance the adaptability and reliability of the imaging system to complex space environments.

[0089] All of the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here.

[0090] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0091] Figure 4 This is a schematic diagram of a space-based microwave imaging system design device for space targets provided in an embodiment of this application. Figure 4 As shown, the device includes:

[0092] Simulation module 401 is configured to determine the rendezvous process between the observation satellite and the space target based on orbital dynamics simulation methods, and then determine the imaging observation window.

[0093] The scanning strategy determination module 402 is configured to determine the beam scanning geometry by combining the relative motion characteristics of the observed satellite and the space target in the imaging observation window and the maximum scanning capability of the phased array antenna, and generate a beam scanning strategy adapted to the high-speed relative motion of the observed satellite and the space target.

[0094] The imaging module 403 is configured to sequentially perform beam widening acquisition, angle measurement and ranging, orbit optimization and narrow beam imaging to optimize the orbit prediction error of space targets and achieve accurate beam acquisition and locking.

[0095] The compensation module 404 is configured to achieve high-precision imaging of the space target by combining the synthetic aperture imaging algorithm with error compensation, based on the beam scanning strategy and the optimized orbital parameters of the space target.

[0096] According to the technical solution provided in this application, the intersection process between the observation satellite and the space target is first determined based on the orbital dynamics simulation method, and then the imaging observation window is determined. Then, the beam scanning geometry is determined by combining the relative motion characteristics of the observation satellite and the space target in the imaging observation window and the maximum scanning capability of the phased array antenna, and a beam scanning strategy adapted to the high-speed relative motion of the observation satellite and the space target is generated. Next, beam broadening acquisition, angle measurement and ranging, orbit optimization and narrow beam imaging are executed in sequence to optimize the orbit prediction error of the space target and achieve accurate beam acquisition and locking. Finally, based on the beam scanning strategy and the optimized orbit parameters of the space target, high-precision imaging of the space target is achieved by combining the synthetic aperture imaging algorithm and error compensation. This enables the determination of feasible positions for dual high-speed motion imaging, constructs a stable and efficient phased array beam scanning strategy, realizes high-precision beam pointing of non-cooperative targets, and improves the accuracy and reliability of space target imaging.

[0097] In some implementations, the rendezvous process between the observation satellite and the space target is determined based on orbital dynamics simulation methods. This includes: building a space-based microwave imaging simulation scenario of the space target using an orbital dynamics simulation platform, setting the scenario time period, initializing the orbital epochs and orbital parameters of the observation satellite and the space target, and obtaining the radar payload parameters of the observation satellite; the radar payload parameters include at least the radar wavelength. Imaging distance and azimuth resolution Using radar equations as range constraints, the predicted distance between the observed satellite and the space target is determined based on orbital dynamics simulation. The satellite trajectories and space target trajectories when the predicted distance is less than a preset distance threshold are identified as candidate intersection segments, thereby determining the duration of the intersection between the observed satellite and the space target. and minimum distance The angular velocity of the observation satellite pointing towards the space target is determined to be... The intersection segment with the minimum angular velocity is determined as the target imaging interval; the synthetic aperture length of the radar is determined as... The maximum imaging distance is determined as follows: And within the target imaging range, the observation window is determined based on the maximum imaging distance; where, To find the minimum value function, This represents the azimuth scanning angle of the radar antenna.

[0098] In some implementations, the beam scanning geometry is determined by combining the relative motion characteristics of the observed satellite and the space target within the imaging observation window with the maximum scanning capability of the phased array antenna, including: based on the space target velocity... Observing satellite speed and the orbital angle between the observation satellite and the space target Determine the angle of the scanning plane as Then, the scanning plane is determined in the inertial coordinate system; the attitude of the observation satellite is adjusted so that the maximum scanning capability plane of the phased array antenna coincides with the scanning plane; based on the maximum scanning angle of the phased array antenna and the phased array antenna after attitude adjustment, the unique scanning plane and the beam allowable coverage area are determined, and then the beam scanning geometry is determined.

[0099] In some implementations, the beam scanning strategy is determined by acquiring the azimuth projection velocity of the space target within the beam scanning geometry. According to the formula Determine the real-time azimuth angle of a space target within the beam scanning geometry. ;in, The initial azimuth angle, For a moment The slant range between the observation satellite and the space target. For a moment Azimuth projection velocity; obtain the pitch projection velocity of a space target within the beam scanning geometry. According to the formula Determine the real-time elevation angle of a space target within the beam scanning geometry. ;in, The initial pitch angle, For a moment The pitch projection velocity; and the time series fitting model of the real-time azimuth angle are constructed respectively. Time series fitting model of real-time pitch angle The beam scanning pattern of the phased array antenna is obtained; among which, Radar power-on duration, is the fitting coefficient, and n is a positive integer.

[0100] In some implementations, the beam scanning strategy is further determined as follows: the azimuth angular velocity of the space target within the beam scanning geometry is determined as... This allows us to determine the time it takes for a space target to pass through the main lobe of the antenna once. ;in, The azimuth beamwidth is 3dB. For beamwidth factor, To observe the slant range between the satellite and the space target; to obtain the orbit prediction error of the space target; and to determine the projection of the orbit prediction error into the beam scanning geometry. ;based on and The detection start-up and shutdown advance amount is determined to be ;in, This refers to the azimuth coverage area of ​​the radar beam. ;in, The azimuth beamwidth is 3dB. The range is 3dB beamwidth.

[0101] In some implementations, the precise acquisition and locking of the beam is achieved by widening the radar beam by a factor of 1. Broadening, to obtain the broadened azimuth beamwidth. and the widened range beamwidth ;based on and The initial detection of the space target will be conducted to obtain its initial location; the initial location will include at least the distance between the observation satellite and the space target. Azimuth Pitch angle The initial target coordinates are transformed from the antenna coordinate system to the inertial frame. The initial coordinates of the space target in the inertial frame are determined by combining the orbital position and attitude parameters of the observed satellite. The initial coordinates are then optimized to obtain the optimized orbital coordinates. The sum of the positional errors between the optimized orbital coordinates and the initial target coordinates is less than a preset threshold. Based on the optimized orbital coordinates, the radar is switched to a narrow beam mode, and the target is locked by updating the beam pointing. The narrow beam width is the original 3dB beam width of the radar. A closed-loop beam pointing control is constructed, iteratively executing the steps of acquiring real-time detection targets, optimizing the orbit using real-time detection targets, switching the radar to a narrow beam mode based on the optimized orbital coordinates, and locking the target by updating the beam pointing, to ensure that the beam center is always aligned with the target during the imaging phase. The beam pointing includes the real-time azimuth angle. and real-time pitch angle .

[0102] In some implementations, trajectory optimization is performed using real-time detection points, including: based on the original trajectory prediction of the space target, limiting the optimization range of the six orbital elements; and determining the objective function as... ;in, To optimize the orbit at time The position vector, To detect the trace at time The position vector, To detect the number of points, a numerical optimization algorithm was used to optimize the orbital parameters of the space target, resulting in optimized orbital coordinates.

[0103] In some implementations, the error formula for beam pointing closed-loop control is: ;in, For beam pointing closed-loop control error, The beam pointing command angle, For actual feedback angle, This is the pointing error threshold.

[0104] In some implementations, high-precision imaging of space targets is achieved by combining synthetic aperture imaging algorithms and error compensation, based on beam scanning strategies and optimized orbital parameters of the space targets. This includes: determining the relative velocity between the target satellite and the observation satellite in the equatorial coordinate system based on their three-dimensional coordinates during the imaging period; performing translational motion compensation on the radar echo data based on the relative velocity; optimizing Doppler parameters and refining imaging compensation on the radar echo data after translational motion compensation to eliminate first-order range migration; converting platform position errors, payload electronic device errors, antenna pattern errors, and orbit prediction errors of the space targets in the observation satellite into phase or amplitude perturbations in the radar echo data, and then using the converted phase or amplitude perturbations to compensate for errors in the radar echo data after Doppler parameter optimization and refining imaging compensation.

[0105] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0106] Figure 5 This is a schematic diagram of the electronic device provided in an embodiment of this application. For example... Figure 5 As shown, the electronic device 5 of this embodiment includes: a processor 501, a memory 502, and a computer program 503 stored in the memory 502 and executable on the processor 501. When the processor 501 executes the computer program 503, it implements the steps in the various method embodiments described above. Alternatively, when the processor 501 executes the computer program 503, it implements the functions of each module / unit in the various device embodiments described above.

[0107] Electronic device 5 can be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 5 may include, but is not limited to, processor 501 and memory 502. Those skilled in the art will understand that... Figure 5 This is merely an example of electronic device 5 and does not constitute a limitation on electronic device 5. It may include more or fewer components than shown, or different components.

[0108] The processor 501 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0109] The memory 502 can be an internal storage unit of the electronic device 5, such as a hard disk or RAM of the electronic device 5. The memory 502 can also be an external storage device of the electronic device 5, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, etc., equipped on the electronic device 5. The memory 502 can also include both internal and external storage units of the electronic device 5. The memory 502 is used to store computer programs and other programs and data required by the electronic device.

[0110] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0111] If an integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program may include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium may include: any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0112] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for designing a space-based microwave imaging system for space targets, characterized in that, include: The rendezvous process between the observation satellite and the space target is determined based on orbital dynamics simulation methods, thereby determining the imaging observation window; The beam scanning geometry is determined by combining the relative motion characteristics of the observed satellite and the space target in the imaging observation window with the maximum scanning capability of the phased array antenna, and a beam scanning strategy adapted to the high-speed relative motion of the observed satellite and the space target is generated. The beam broadening acquisition, angle measurement and ranging, orbit optimization and narrow beam imaging are executed sequentially to optimize the orbit prediction error of space targets and achieve accurate beam acquisition and locking. Based on the beam scanning strategy and the optimized orbital parameters of the space target, high-precision imaging of the space target is achieved by combining the synthetic aperture imaging algorithm with error compensation. The precise acquisition and locking of the beam is achieved in the following way: Radar beams are widened by multiples Broadening, to obtain the broadened azimuth beamwidth. and the widened range beamwidth ;in, The azimuth beamwidth is 3dB. The range-direction beamwidth is 3dB. based on and The space target will be initially probed to obtain its initial location; the initial location will include at least the distance between the observation satellite and the space target. Azimuth Pitch angle ; The initial point trace is transformed from the antenna coordinate system to the inertial frame, and the initial coordinates of the space target in the inertial frame are determined by combining the orbital position and attitude parameters of the observation satellite in the inertial frame. The initial coordinates are optimized to obtain optimized orbit coordinates; the sum of the positional errors between the optimized orbit coordinates and the initial point trace is less than a preset threshold. The radar switches to narrow beam mode based on the optimized orbit coordinates and locks onto space targets by updating the beam pointing; the beam width of the narrow beam is the original 3dB beam width of the radar. A beam pointing closed-loop control is constructed, and the steps of acquiring real-time detection points, optimizing the trajectory using real-time detection points, switching the radar to a narrow beam mode based on the optimized trajectory coordinates, and locking onto the space target by updating the beam pointing are executed iteratively to ensure that the beam center is always aligned with the space target during the imaging phase. The beam pointing includes the real-time azimuth angle. and real-time pitch angle .

2. The space-based microwave imaging system design method for space targets according to claim 1, characterized in that, The rendezvous process between the observation satellite and the space target was determined based on orbital dynamics simulation methods, including: A space-based microwave imaging simulation scenario for a space target was built using an orbital dynamics simulation platform. The scenario time period was set, the orbital epochs and orbital parameters of the observation satellite and the space target were initialized, and the radar payload parameters of the observation satellite were acquired. These radar payload parameters include at least the radar wavelength. Imaging distance and azimuth resolution ; Using radar equations as range constraints, the predicted distance between the observed satellite and the space target is determined based on orbital dynamics simulation; The observation satellite chronology and the space target chronology when the predicted distance is less than a preset distance threshold are identified as candidate intersection segments, thereby determining the duration of the intersection between the observation satellite and the space target. and minimum distance ; The angular velocity of the observation satellite pointing towards the space target is determined to be: The intersection segment with the minimum angular velocity is determined as the target imaging interval; The synthetic aperture length of the radar is determined to be... ; The maximum imaging distance is determined as And within the target imaging range, an observation window is determined based on the maximum imaging distance; wherein, To find the minimum value function, This represents the azimuth scanning angle of the radar antenna.

3. The space-based microwave imaging system design method for space targets according to claim 1, characterized in that, The beam scanning geometry is determined by combining the relative motion characteristics of the observed satellite and space target within the imaging observation window with the maximum scanning capability of the phased array antenna, including: Based on the speed of the space target Observing satellite speed and the orbital angle between the observation satellite and the space target Determine the angle of the scanning plane as Then, the scanning plane is determined in the inertial coordinate system; The attitude of the observation satellite is adjusted so that the maximum scanning capability plane of the phased array antenna coincides with the scanning plane; The unique scanning plane and the allowable beam coverage area are determined based on the maximum scanning angle and attitude adjustment of the phased array antenna, thereby determining the beam scanning geometry.

4. The space-based microwave imaging system design method for space targets according to claim 3, characterized in that, The beam scanning strategy is determined in the following manner: Obtain the azimuth projection velocity of the space target within the beam scanning geometry. According to the formula Determine the real-time azimuth angle of the space target within the beam scanning geometry. ;in, The initial azimuth angle, For a moment The slant range between the observation satellite and the space target. For a moment azimuth projection velocity; Obtain the pitch projection velocity of the space target within the beam scanning geometry. According to the formula Determine the real-time pitch angle of the space target within the beam scanning geometry. ;in, The initial pitch angle, For a moment The pitch projection velocity; Construct time series fitting models for the real-time azimuth angles respectively. and the time series fitting model of the real-time pitch angle The beam scanning pattern of the phased array antenna is obtained; among which, Radar power-on duration, is the fitting coefficient, and n is a positive integer.

5. The space-based microwave imaging system design method for space targets according to claim 4, characterized in that, The beam scanning strategy is also determined in the following manner: The azimuth angular velocity of the space target within the beam scanning geometry is determined as follows: This allows us to determine the time it takes for a space target to pass through the main lobe of the antenna once. ;in, The azimuth beamwidth is 3dB. For beamwidth factor, To observe the slant range between satellites and space targets; The orbit prediction error of a space target is obtained, and the projection of the orbit prediction error into the beam scanning geometry is determined. ; Based on the above and stated The detection start-up and shutdown advance amount is determined to be ;in, This refers to the azimuth coverage area of ​​the radar beam. .

6. The space-based microwave imaging system design method for space targets according to claim 1, characterized in that, Track optimization using real-time detection points includes: Based on the original orbit prediction of the space target, the optimization range of the number of six orbital elements is limited; The objective function is determined as follows: ;in, To optimize the orbit at time The position vector, To detect the trace at time The position vector, To detect the number of dots, Represents the square of the L2 norm; The orbital parameters of the space target are optimized using a numerical optimization algorithm to obtain the optimized orbital coordinates.

7. The space-based microwave imaging system design method for space targets according to claim 1, characterized in that, The error formula for the beam pointing closed-loop control is: ;in, For beam pointing closed-loop control error, The beam pointing command angle, For actual feedback angle, This is the pointing error threshold.

8. The space-based microwave imaging system design method for space targets according to claim 2, characterized in that, Based on the beam scanning strategy and the optimized orbital parameters of the space target, high-precision imaging of the space target is achieved by combining a synthetic aperture imaging algorithm with error compensation, including: The relative motion velocity between the target satellite and the observation satellite in the equatorial coordinate system is determined based on the three-dimensional coordinates of the target satellite and the observation satellite during the imaging time period, and translational motion compensation is performed on the radar echo data based on the relative motion velocity. Doppler parameter optimization and refined imaging compensation are performed on the radar echo data after translational motion compensation to eliminate the first-order range migration. The platform position error, payload electronic device error, antenna pattern error, and orbit prediction error of the space target in the observation satellite are converted into phase perturbations or amplitude perturbations in the radar echo data, respectively. Then, the converted phase perturbations or amplitude perturbations are used to compensate for errors in the radar echo data after Doppler parameter optimization and refined imaging compensation.

9. A design device for a space-based microwave imaging system for space targets, characterized in that, include: The simulation module is configured to determine the rendezvous process between the observation satellite and the space target based on orbital dynamics simulation methods, and then determine the imaging observation window; The scanning strategy determination module is configured to determine the beam scanning geometry by combining the relative motion characteristics of the observed satellite and the space target in the imaging observation window and the maximum scanning capability of the phased array antenna, and generate a beam scanning strategy adapted to the high-speed relative motion of the observed satellite and the space target. The imaging module is configured to sequentially perform beam widening acquisition, angle measurement and ranging, orbit optimization and narrow beam imaging to optimize the orbit prediction error of space targets and achieve accurate beam acquisition and locking. The compensation module is configured to achieve high-precision imaging of the space target by combining the synthetic aperture imaging algorithm with error compensation based on the beam scanning strategy and the optimized orbital parameters of the space target. The precise acquisition and locking of the beam is achieved in the following way: Radar beams are widened by multiples Broadening, to obtain the broadened azimuth beamwidth. and the widened range beamwidth ;in, The azimuth beamwidth is 3dB. The range-direction beamwidth is 3dB. based on and The space target will be initially probed to obtain its initial location; the initial location will include at least the distance between the observation satellite and the space target. Azimuth Pitch angle ; The initial point trace is transformed from the antenna coordinate system to the inertial frame, and the initial coordinates of the space target in the inertial frame are determined by combining the orbital position and attitude parameters of the observation satellite in the inertial frame. The initial coordinates are optimized to obtain optimized orbit coordinates; the sum of the positional errors between the optimized orbit coordinates and the initial point trace is less than a preset threshold. The radar switches to narrow beam mode based on the optimized orbit coordinates and locks onto space targets by updating the beam pointing; the beam width of the narrow beam is the original 3dB beam width of the radar. A beam pointing closed-loop control is constructed, and the steps of acquiring real-time detection points, optimizing the trajectory using real-time detection points, switching the radar to a narrow beam mode based on the optimized trajectory coordinates, and locking onto the space target by updating the beam pointing are executed iteratively to ensure that the beam center is always aligned with the space target during the imaging phase. The beam pointing includes the real-time azimuth angle. and real-time pitch angle .

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 computer program, it implements the steps of the space target space-based microwave imaging system design method as described in any one of claims 1 to 8.

11. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the space target space-based microwave imaging system design method as described in any one of claims 1 to 8.

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