Ais beacon guidance sar satellite imaging method fusing beidou short message

Abstract

This invention provides an AIS beacon-guided SAR satellite imaging method integrating BeiDou short message service, comprising: receiving target imaging commands; parsing the acquired AIS beacon signals of each vessel to extract vessel characteristic attribute information and status information; matching the vessel characteristic attribute information of each vessel with target identification information to select at least one target vessel; selecting at least one target to be imaged from the at least one target vessel based on the status information and the satellite's own orbital parameters, and generating imaging task parameters; controlling the SAR payload to perform imaging operations on the corresponding area of ​​the at least one target to be imaged, generating raw SAR imaging data; and transmitting the data back to the ground terminal through a dual-channel transceiver channel according to priority, thereby improving the satellite's dynamic response capability, enhancing the reliability of the data transmission link, and improving the real-time performance of emergency imaging data.

Description

Technical Field

[0001] This invention relates to the fields of remote sensing SAR satellite technology and communication technology, and in particular to an AIS beacon-guided SAR satellite imaging method that integrates BeiDou short message service. Background Technology

[0002] Traditional remote sensing SAR satellites face numerous technical bottlenecks during their on-orbit operation.

[0003] First, the high dependence on ground-based systems leads to insufficient dynamic response capabilities. Existing SAR satellite imaging missions heavily rely on preset commands from ground-based telemetry and control systems, requiring advance planning and parameter uploading via ground stations. Due to frequent satellite entry and exit from Earth and limited ground-based telemetry and control resources, users must plan missions based on satellite orbital cycles and ground station availability, making real-time response to unforeseen events impossible.

[0004] Secondly, the data transmission link has vulnerabilities. Traditional satellite data transmission relies on ground station coverage. In complex scenarios such as the open sea and special areas, imaging data cannot be transmitted back in real time, resulting in delays in emergency response.

[0005] Therefore, how to improve the satellite's dynamic response capability, enhance the reliability of data transmission links, and ensure the real-time nature of emergency imaging data are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0006] This invention provides an AIS beacon-guided SAR satellite imaging method that integrates BeiDou short message service to improve satellite dynamic response capabilities, enhance data transmission link reliability, and ensure the real-time performance of emergency imaging data.

[0007] On the one hand, this invention provides an AIS beacon-guided SAR satellite imaging method that integrates BeiDou short message service, comprising:

[0008] The system receives target imaging commands sent by a ground terminal via the BeiDou short message transceiver channel; the target imaging commands include target identification information.

[0009] The AIS beacon signals of each vessel are analyzed to extract the vessel's characteristic attributes and status information.

[0010] The ship characteristic attribute information of each ship is matched with the target identification information to filter out at least one target ship;

[0011] Based on the state information and the satellite's own orbital parameters, on-board autonomous mission planning is performed, at least one target to be imaged is selected from the at least one target ship, and imaging mission parameters are generated.

[0012] Based on the imaging task parameters, the SAR payload is controlled to perform imaging operations on the corresponding area of ​​the at least one target to be imaged, generating raw SAR imaging data.

[0013] The raw SAR imaging data is processed to obtain first-type target imaging data and second-type target imaging data. The first-type target imaging data is transmitted back to the ground terminal through the BeiDou short message transceiver channel, and the second-type target imaging data is transmitted back to the ground terminal through the conventional data transceiver channel. The first-type target imaging data has a higher priority than the second-type target imaging data.

[0014] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short messages is provided, wherein the target imaging command further includes imaging requirement information;

[0015] Based on the aforementioned state information and the satellite's own orbital parameters, on-board autonomous mission planning is performed, selecting at least one target to be imaged from the at least one target vessel, and generating imaging mission parameters, including:

[0016] Using a kinematic model, based on the state information and the satellite's own orbital parameters, the motion trajectory of the at least one target vessel is predicted;

[0017] The target ship corresponding to the motion trajectory that enters the imaging coverage of the SAR payload is taken as the target to be imaged, and the imaging window time is generated based on the time when the motion trajectory enters and exits the imaging coverage of the SAR payload.

[0018] Based on the imaging window time, the motion trajectory of the target to be imaged, and the imaging requirement information, the imaging task parameters are generated; wherein, the imaging task parameters include satellite attitude parameters and imaging mode parameters.

[0019] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short message service is provided, which controls the SAR payload to perform imaging operations on the corresponding area of ​​at least one target to be imaged, generating raw SAR imaging data based on the imaging mission parameters, including:

[0020] At a preset first time point before the imaging window arrives, satellite attitude adjustment is triggered to meet the satellite attitude parameters.

[0021] At a preset second time point before the imaging window arrives, the SAR payload is controlled to power on and warm up.

[0022] During the imaging window, the SAR payload is controlled to call an imaging mode template that matches the imaging mode parameters, perform imaging operations, and generate raw SAR imaging data.

[0023] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short message service is provided, which triggers satellite attitude adjustment to meet the satellite attitude parameters, including:

[0024] Based on the imaging requirements and the ship characteristic attributes of the target to be imaged, calculate the roll angle required for satellite attitude maneuvering and the yaw guidance angle used to compensate for Earth's rotation.

[0025] The control reaction flywheel drives the SAR satellite to perform a roll maneuver, and the star sensor is used to perform closed-loop control of the satellite attitude until the attitude is stabilized in the required imaging attitude of the satellite attitude parameters.

[0026] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short message service is provided, wherein the target imaging command further includes the mission urgency and target importance.

[0027] Before generating raw SAR imaging data, the process includes controlling the SAR payload to perform imaging operations on the corresponding region of the at least one target to be imaged, based on the imaging task parameters, and further includes:

[0028] Based on the urgency of the task, the importance of the target, and the status information of the at least one target to be imaged, the imaging priority of the at least one target to be imaged is determined;

[0029] Generate target guidance instructions for the at least one target to be imaged, and store the target guidance instructions for the at least one target to be imaged into the target guidance instructions for the at least one target to be imaged according to the imaging priority of the at least one target to be imaged.

[0030] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short message service is provided, which analyzes the acquired AIS beacon signal of each ship to extract the ship characteristic attribute information and status information of each ship, including:

[0031] The AIS beacon signal is demodulated to convert the radio frequency signal into a digital signal;

[0032] The digital signal is decoded according to a preset communication protocol to identify data frames;

[0033] The decoded data frames are verified, invalid data frames are discarded, and ship characteristic attribute information and status information of each ship are extracted from the valid data frames.

[0034] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short messages is provided. Before generating raw SAR imaging data, the method further includes controlling the SAR payload to perform imaging operations on the corresponding area of ​​at least one target to be imaged based on the imaging mission parameters, and then further comprising:

[0035] Acquire sea state data for the corresponding area of ​​at least one target to be imaged;

[0036] Based on the sea state data, determine the current sea state level;

[0037] Based on the sea state level, the parameters of the SAR payload are adaptively adjusted.

[0038] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short message service is provided, which adaptively adjusts the parameters of the SAR payload based on the sea state level, including:

[0039] When the sea state level is a preset severe sea state level, at least one of the following is used: increasing the incident angle of the SAR payload, adjusting the polarization mode, increasing the pulse repetition frequency, and adjusting the bandwidth.

[0040] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short message service is provided, which further includes:

[0041] When the sea state level is a preset severe sea state level, the SAR payload is controlled to perform multiple imaging operations on the corresponding area of ​​the at least one target to be imaged, thereby acquiring multiple frames of raw SAR imaging data.

[0042] The multi-frame SAR raw imaging data is subjected to image registration and fusion processing to generate SAR fused imaging data, and the first type of target imaging data and the second type of target imaging data are generated based on the SAR fused imaging data.

[0043] According to the present invention, an AIS beacon-guided SAR satellite imaging method integrating BeiDou short message service is provided to acquire sea state data of the corresponding area of ​​at least one target to be imaged, including:

[0044] The system acquires at least one type of sea state data, including wind speed, wind direction, and wave height, through real-time monitoring using onboard sensors; and / or receives sea state data released by ground meteorological departments through the BeiDou short message transceiver channel.

[0045] On the other hand, the present invention also provides an AIS beacon-guided SAR satellite imaging system that integrates BeiDou short message service, comprising:

[0046] The BeiDou short message transceiver module is used to receive target imaging instructions sent by a ground terminal through the BeiDou short message transceiver channel; the target imaging instructions include target identification information.

[0047] The AIS beacon parsing module is used to parse the acquired AIS beacon signals of each ship, extract the ship characteristic attribute information and status information of each ship; and match the ship characteristic attribute information of each ship with the target identification information to filter out at least one target ship.

[0048] The on-board imaging processing module is used to perform on-board autonomous mission planning based on the status information and the satellite's own orbital parameters, select at least one target to be imaged from the at least one target ship, and generate imaging mission parameters.

[0049] The SAR payload and data transmission / storage integrated module is used to control the SAR payload to perform imaging operations on the corresponding area of ​​the at least one target to be imaged according to the imaging task parameters, generating raw SAR imaging data; and to process the raw SAR imaging data to obtain first-type target imaging data and second-type target imaging data, and to transmit the first-type target imaging data back to the ground terminal through the BeiDou short message transceiver channel, and transmit the second-type target imaging data back to the ground terminal through a conventional data transceiver channel, wherein the first-type target imaging data has a higher priority than the second-type target imaging data.

[0050] On the other hand, the present invention also provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the AIS beacon-guided SAR satellite imaging method fused with BeiDou short messages as described above.

[0051] On the other hand, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the AIS beacon-guided SAR satellite imaging method fused with BeiDou short messages as described above.

[0052] On the other hand, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the AIS beacon-guided SAR satellite imaging method fused with BeiDou short messages as described above.

[0053] The present invention provides an AIS beacon-guided SAR satellite imaging method that integrates BeiDou short message service. It receives target imaging commands and transmits high-priority data through the BeiDou short message service and combines AIS beacon parsing with onboard autonomous mission planning to achieve dynamic imaging control. This method solves the technical problems of traditional SAR satellites being highly dependent on the ground and having fragile data transmission links. It has the advantages of improving satellite dynamic response capabilities, enhancing data transmission link reliability, and ensuring the real-time performance of emergency imaging data. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating the AIS beacon-guided SAR satellite imaging method that integrates BeiDou short messages, as provided in an embodiment of the present invention.

[0056] Figure 2 This is a schematic diagram of the structure of the AIS beacon-guided SAR satellite imaging system that integrates BeiDou short messages, provided in an embodiment of the present invention.

[0057] Figure 3 This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0059] In existing technologies, traditional remote sensing SAR satellite systems suffer from technical deficiencies such as strong dependence on ground infrastructure, insufficient dynamic response capabilities, and fragile data transmission links. Current SAR satellite imaging missions rely on pre-set commands from ground-based telemetry and control systems, making real-time response to unexpected events impossible. Data transmission links depend on the coverage area of ​​ground stations, which can easily lead to data transmission delays in remote or complex environments. Furthermore, related technical solutions suffer from ineffective coordination between AIS beacons and BeiDou short message communication, limiting the satellite's autonomous mission planning capabilities.

[0060] To address the aforementioned issues, research revealed a lack of a collaborative mechanism between real-time two-way communication between satellite and ground, and autonomous decision-making. Analysis showed that BeiDou short message service offers low bandwidth but high reliability, enabling the transmission of critical commands; while AIS beacons provide ship dynamic information. Combining these two technologies can construct a closed-loop control link, but the technical challenges of onboard real-time data processing and dynamic task scheduling need to be resolved. Through research on satellite attitude control algorithms, onboard computing resource allocation, and multi-source data fusion, an autonomous imaging control method based on priority task queues was ultimately developed.

[0061] Therefore, this application proposes receiving target imaging commands sent by ground terminals via the BeiDou short message transceiver channel. These commands include target identification information. The application then analyzes the acquired AIS beacon signals of each vessel to extract vessel characteristic attribute information and status information. The vessel characteristic attribute information is matched with the target identification information to filter target vessels. Based on the status information and satellite orbit parameters, on-board autonomous mission planning is performed to generate imaging mission parameters. The SAR payload is controlled to perform imaging operations to generate raw SAR imaging data. The raw data is then classified and processed and transmitted back through different channels. The characteristic attribute information may include specific vessel type, size, shape, Maritime Mobile Service Identity (MMSI), etc.

[0062] Specifically, Figure 1 This is a flowchart illustrating the AIS beacon-guided SAR satellite imaging method that integrates BeiDou short messages, as provided in an embodiment of the present invention.

[0063] like Figure 1 As shown, the execution subject of the AIS beacon-guided SAR satellite imaging method fused with BeiDou short messages provided in this embodiment of the invention can be an electronic device, and the method mainly includes the following steps:

[0064] 101. Receive target imaging instructions sent by a ground terminal via the BeiDou short message transceiver channel; the target imaging instructions include target identification information;

[0065] 102. Analyze the AIS beacon signals of each acquired vessel to extract the vessel's characteristic attribute information and status information;

[0066] 103. Match the ship characteristic attribute information of each ship with the target identification information to filter out at least one target ship;

[0067] 104. Based on the state information and the satellite's own orbital parameters, perform on-board autonomous mission planning, select at least one target to be imaged from the at least one target ship, and generate imaging mission parameters;

[0068] 105. Based on the imaging task parameters, control the SAR payload to perform imaging operations on the corresponding area of ​​the at least one target to be imaged, and generate raw SAR imaging data.

[0069] 106. Process the raw SAR imaging data to obtain first-type target imaging data and second-type target imaging data, and transmit the first-type target imaging data back to the ground terminal through the BeiDou short message transceiver channel, and transmit the second-type target imaging data back to the ground terminal through the conventional data transceiver channel.

[0070] The BeiDou short message transmission channel refers to a wireless transmission channel supporting the BeiDou satellite communication protocol. Specifically, it can utilize the BeiDou RDSS module to achieve two-way communication, receiving ground commands and transmitting critical data. AIS beacon signal parsing refers to the process of demodulating and decoding the radio frequency signals of the Automatic Identification System (AIS). Specifically, it can employ software-defined radio technology to extract ship identity and dynamic information. Onboard autonomous mission planning refers to the real-time calculation process based on orbital mechanics models and ship trajectory predictions. Specifically, it can use the extended Kalman filter algorithm to predict the imaging window time. Imaging mission parameter generation refers to generating a control command set based on target position and satellite attitude constraints. Specifically, it can include side-looking angle, pulse repetition frequency, and imaging mode selection parameters. Data classification and transmission refers to selecting the transmission channel based on data priority. Specifically, it can use metadata compression algorithms to transmit critical information via BeiDou short messages.

[0071] Specifically, after the satellite receives the target identification information sent via BeiDou short message, the onboard processor initiates the AIS signal scanning program. By demodulating the AIS radio frequency signal, the ship's MMSI code and position coordinates are obtained, and the ship type is matched with the target identification information. After filtering out ships that meet preset conditions, the future imaging time window is calculated based on the satellite orbit parameters. The time point when the ship enters the SAR coverage area is predicted based on its speed and heading, generating a command sequence containing attitude adjustment parameters and imaging modes. Within the predetermined time window, the SAR payload is controlled to complete imaging, while the raw data is classified in real time to obtain first-class target imaging data and second-class target imaging data, with the first-class target imaging data having higher priority than the second-class target imaging data. Key data (i.e., first-class target imaging data) is immediately transmitted back via the BeiDou short message channel, while non-key data (i.e., second-class target imaging data, which may include the raw SAR imaging data) is transmitted via a conventional data transceiver channel (such as an X-band data link) when the satellite passes over the ground station. The conventional data transceiver channel is a channel with transmission performance lower than the BeiDou short message transceiver channel.

[0072] Compared to existing technologies, current solutions typically employ a single AIS guidance or ground-preset command mode, failing to achieve real-time space-to-ground interaction. For example, some existing technologies rely solely on AIS information for target selection, lacking an integrated BeiDou communication module, thus hindering the reception of urgent mission commands. This solution, however, constructs a dual-channel communication architecture, maintaining AIS target tracking capabilities while utilizing BeiDou short message service for dynamic mission priority adjustment, resolving the response delay issue of traditional systems. Furthermore, the application of an onboard autonomous mission planning module avoids frequent reliance on ground stations for orbit calculations, enhancing the satellite's operational capabilities in invisible arc segments.

[0073] Through the above technical solutions, this application achieves real-time monitoring and rapid response to moving targets at sea. In long-range search and rescue scenarios, the ground command center can quickly upload information about distressed vessels via BeiDou short message service. Upon receiving the command, the satellite immediately initiates target tracking and imaging procedures, avoiding the delays of traditional systems that require waiting for the satellite to pass over the ground station before receiving commands. The classification and transmission mechanism of imaging data ensures that critical information arrives first, providing timely support for rescue decisions. The onboard autonomous planning function reduces the occupation of ground tracking and control resources, enabling the satellite to handle multiple batches of emergency missions.

[0074] In some embodiments, this application further proposes that the target imaging command also includes imaging requirement information; based on state information and the satellite's own orbital parameters, perform on-board autonomous mission planning, select at least one target to be imaged from at least one target vessel, and generate imaging mission parameters, including: using a kinematic model, based on state information and the satellite's own orbital parameters, predicting the motion trajectory of at least one target vessel; taking the target vessel corresponding to the motion trajectory entering the imaging coverage of the SAR payload as the target to be imaged, and generating an imaging window time based on the time of the motion trajectory entering and leaving the imaging coverage of the SAR payload; generating imaging mission parameters based on the imaging window time, the motion trajectory of the target to be imaged, and imaging requirement information; wherein, the imaging mission parameters include satellite attitude parameters and imaging mode parameters.

[0075] The kinematic model refers to the mathematical model used to predict the trajectory of a ship. Specifically, it can be implemented using the ship's motion equations based on Newton's laws of motion, combined with the ship's position, speed, and heading parameters, to calculate the ship's position change over future time. This model addresses the problem that traditional satellites cannot dynamically predict target position changes, ensuring the accuracy of the imaging window time.

[0076] The imaging coverage area refers to the spatial region that the SAR payload can effectively image under a specific attitude. It can be calculated using the beamwidth of the SAR antenna and the satellite orbital altitude parameters, and is used to filter target ships entering the imageable area. This parameter solves the problem of missed images caused by the fixed imaging range of traditional satellites.

[0077] The imaging window time refers to the time interval between the target vessel entering and leaving the SAR payload's imaging coverage area. It can be calculated using the spatial geometric relationship between the vessel's trajectory and the imaging coverage area, and is used to determine the optimal activation time for the SAR payload. This parameter addresses the mismatch between satellite resource scheduling and dynamic changes in the target.

[0078] The satellite attitude parameters include roll angle and yaw guidance angle. Specifically, the required attitude angles for the satellite can be calculated using a coordinate transformation matrix to compensate for the impact of Earth's rotation on imaging geometry. This parameter solves the problem of target position offset caused by Earth's rotation during side-looking imaging.

[0079] The imaging mode parameters include resolution, polarization, and pulse repetition frequency, which can be selected by matching a preset imaging mode template library to meet the imaging needs of different application scenarios. This parameter solves the problem of image quality mismatch between traditional satellite imaging modes and mission requirements. Imaging modes can include spotlight mode, strip mode, and sliding spotlight mode, among others.

[0080] Specifically, after the satellite receives a target imaging command containing imaging requirements, it first parses the target identification information and imaging parameter requirements in the command. It then acquires the real-time position, speed, and heading data of the target vessel using the onboard AIS receiver and predicts the vessel's trajectory over a future time period using a kinematic model. Based on the SAR payload's imaging coverage parameters, vessels whose trajectories intersect with the imaging area are selected as targets to be imaged. Subsequently, the time points when the target vessel enters and leaves the imaging coverage area are calculated to generate a precise imaging window. Combining the resolution, coverage, and other requirements specified in the imaging requirements, corresponding parameter combinations are matched from a pre-set imaging mode template library. Simultaneously, the roll angle that needs adjustment is calculated based on the satellite's orbital parameters to align with the corresponding area of ​​at least one target to be imaged, and the yaw guidance angle is calculated to compensate for geometric distortion caused by the Earth's rotation. The final generated imaging mission parameters will simultaneously include attitude control commands and payload operating mode configurations, ensuring high-quality imaging is completed within the predetermined time window.

[0081] Compared to existing technologies, traditional SAR satellite imaging mission planning relies on preset parameters from ground stations and cannot adjust the imaging window in real time according to the dynamic trajectory of the ship. For example, some existing technologies only use static AIS position information to plan imaging, without considering trajectory changes caused by ship motion. This solution predicts the trajectory through a kinematic model and combines it with real-time orbital parameter calculations to control the imaging window time error within the second range. At the same time, through joint optimization of attitude parameters and imaging modes, it solves the technical challenges of dynamic target tracking and imaging parameter adaptation.

[0082] Through the above technical solution, this application achieves accurate prediction of the imaging window for moving vessels, ensuring that the SAR payload starts imaging at the optimal time. By dynamically generating mission parameters that include attitude adjustment and imaging mode, imaging failure or image quality degradation caused by target position offset is effectively avoided. At the same time, parameter templates are automatically matched according to imaging requirements, significantly improving imaging adaptability in different application scenarios.

[0083] In some embodiments, this application further proposes a technical means to trigger satellite attitude adjustment at a preset first time point before the imaging window arrives to meet satellite attitude parameters, control the SAR payload to start up and warm up at a preset second time point before the imaging window arrives, and control the SAR payload to call an imaging mode template that matches the imaging mode parameters to perform imaging operations and generate raw SAR imaging data during the imaging window.

[0084] Triggering satellite attitude adjustment refers to calculating the roll angle and yaw guidance angle required for satellite attitude maneuvers based on imaging needs. Specifically, this can be achieved by using a reaction flywheel to drive the satellite to perform roll maneuvers and by using a star sensor for closed-loop control, ensuring that the satellite achieves attitude stability before the imaging window arrives.

[0085] Among them, controlling the SAR payload to start up refers to powering on the radar system before the imaging window time arrives. This can be achieved through a phased power supply control circuit to avoid instantaneous power surges affecting the equipment's lifespan.

[0086] Calling the imaging mode template refers to automatically matching the corresponding set of radar operating parameters according to the preset imaging mode parameters. Specifically, it can be achieved by using multiple sets of parameter configuration files pre-stored in the onboard memory, which supports quick switching between imaging modes with different resolutions and coverage areas.

[0087] Specifically, after receiving the imaging mission parameters, the satellite's integrated electronic module first plans and executes steps according to a preset time sequence. Five minutes before the imaging window arrives, the attitude control system activates the reaction wheel based on the calculated roll and yaw guidance angles, driving the satellite to perform a roll maneuver. The star sensor monitors the satellite's attitude angles in real time and stabilizes the satellite in the required imaging attitude through closed-loop feedback control. Two minutes before the imaging window arrives, the SAR payload power management unit gradually powers on according to a predetermined program, allowing key components such as the radar transmitter and receiver to enter a preheating state, ensuring that the equipment temperature and electrical performance reach stable operating conditions. When the imaging window arrives, the SAR payload control unit retrieves the imaging mode template matching the mission from the parameter library, such as the pulse width and repetition frequency parameter combination corresponding to the spotlight mode, automatically configures the radar system, and initiates the imaging operation.

[0088] Compared to existing technologies, traditional SAR satellite imaging missions typically execute attitude adjustment and payload activation at a single point in time, which can easily lead to missed imaging windows due to equipment response delays. This solution uses phased timing planning to separate attitude adjustment, equipment warm-up, and imaging execution into independent and controllable steps, ensuring that each step is fully completed before proceeding to the next stage.

[0089] Through the above technical solution, this application solves the problem of decreased imaging quality caused by unstable equipment status during the dynamic mission execution of SAR satellites. By adopting a phased control strategy, it ensures that the radar system performs imaging tasks in the best working state, while avoiding mutual interference between attitude maneuvers and equipment power-on, thereby improving the imaging success rate and data reliability.

[0090] In some embodiments, this application further proposes a method for triggering satellite attitude adjustment to meet satellite attitude parameters, including: calculating the roll angle required for satellite attitude maneuvering and the yaw guidance angle for compensating for Earth's rotation based on imaging requirement information and ship characteristic attribute information of the target to be imaged; controlling the reaction flywheel to drive the SAR satellite to perform roll maneuvering, and using a star sensor to perform closed-loop control of the satellite attitude until the attitude stabilizes at the required imaging attitude of the satellite attitude parameters.

[0091] The roll angle refers to the angle by which the satellite rotates around its longitudinal axis. It can be calculated using the spatial geometric relationship between the satellite's orbital parameters and the target's position, and is used to adjust the side-looking observation angle of the SAR payload. This parameter directly affects the radar beam's coverage of the target; precise calculation ensures accurate imaging coverage of the target vessel.

[0092] The yaw guidance angle refers to the angle by which the satellite rotates around its vertical axis. It can be calculated using a vector synthesis method of the Earth's rotational angular velocity and the satellite's orbital velocity, and is used to compensate for imaging offsets caused by the Earth's rotation. This parameter compensates for the relative displacement of the target position caused by the Earth's rotation, ensuring the stability of the beam pointing during imaging.

[0093] The reaction flywheel is an actuator that adjusts attitude through angular momentum exchange. Specifically, it can be a momentum wheel assembly with three orthogonally arranged axes, generating control torque by changing the flywheel's rotational speed. This device enables precise attitude maneuvering without propellant consumption, meeting the long-term on-orbit operational requirements of satellites.

[0094] The star sensor is a high-precision attitude measurement device based on stellar orientation measurements. Specifically, it can employ a CCD imaging device combined with a stellar database matching algorithm to output real-time three-axis attitude data of the satellite. This device provides feedback signals to the closed-loop control system, ensuring that the attitude adjustment process achieves the predetermined accuracy.

[0095] Specifically, upon receiving the ship's characteristic attribute information of the target to be imaged, a geometric projection model is established based on the ship's size, shape, heading, and imaging resolution requirements. The relative positional relationship between the satellite and the target is calculated through coordinate transformation, and the optimal roll angle parameters are obtained by combining the beamwidth characteristics of the SAR payload. Simultaneously, based on the vector relationship between the satellite's orbital velocity and the Earth's rotational angular velocity, a motion compensation equation is established to solve for the yaw guidance angle. The attitude control system drives the reaction flywheel to generate control torque, causing the satellite to rotate around its longitudinal axis to the target roll angle. During this process, the star sensor continuously collects current attitude angle data and compares it with the set value. The flywheel speed is dynamically adjusted through a PID control algorithm until the attitude error converges to within the allowable range. Once the satellite attitude stabilizes at the predetermined parameters, the SAR payload can perform high-precision imaging operations under conditions that eliminate the influence of the Earth's rotation.

[0096] Compared to existing technologies, traditional satellite attitude adjustment methods rely on ground stations to pre-upload fixed parameters, making dynamic calculations based on real-time target characteristics impossible. This solution achieves real-time attitude optimization for dynamic targets by autonomously calculating roll and yaw guidance angles onboard, thus resolving the imaging blurring problem caused by the Earth's rotation.

[0097] Through the above technical solutions, this application achieves on-board autonomous attitude parameter calculation and high-precision closed-loop control, effectively improving the imaging clarity of SAR satellites for moving targets. By dynamically compensating for azimuth offset caused by Earth's rotation, the stability of beam pointing during side-looking imaging is ensured. The collaborative control mechanism of the reaction flywheel and star sensor enables the satellite to complete attitude adjustments with sub-radian accuracy without ground intervention, meeting the high-resolution imaging requirements of moving targets at sea.

[0098] In some embodiments, this application further proposes that the target imaging instruction includes task urgency and target importance; determine the imaging priority of at least one target to be imaged based on task urgency, target importance and the status information of at least one target to be imaged; generate target guidance instructions for at least one target to be imaged, and store the target guidance instructions in the target guidance instruction queue according to the imaging priority.

[0099] The mission urgency level refers to the required timeliness of the ground terminal's response to the imaging mission. This can be achieved through numerical grading or classification labels, such as categorizing missions into four levels: urgent, high, medium, and low, to guide satellite mission scheduling. Target importance refers to the value weight of the vessel to be imaged in the monitoring mission. This can be determined by vessel type, tonnage, or a pre-defined whitelist. For example, ships and vessels in distress are marked as high-importance targets, or abnormalities such as accidents or abnormal speeds are also considered. Status information refers to the vessel's real-time position, speed, and heading data, which can be obtained by parsing AIS beacon signals to assess the likelihood of the target entering the imaging window. The imaging priority determination method involves weighting the mission urgency, target importance, and status information. This can be implemented using linear weighting or fuzzy logic algorithms; for example, emergency search and rescue missions automatically receive the highest priority.

[0100] Specifically, when the satellite receives imaging commands that include the mission urgency and target importance, it first extracts the real-time position and motion parameters of the target vessel from the AIS parsed data. Using a pre-defined priority evaluation model, the mission urgency is mapped to a time sensitivity coefficient, and the target importance is mapped to a weighting factor. A comprehensive score is then calculated by combining the vessel's current position with its predicted trajectory. The score results are used to generate target guidance commands with priority tags, which are stored in a command queue according to priority. Before executing the imaging mission, the satellite's integrated electronic module prioritizes high-priority commands for attitude adjustment and payload control, ensuring the timely execution of critical tasks.

[0101] Compared to existing technologies, traditional SAR satellite mission scheduling relies solely on preset timing sequences or fixed priority rules, making it unable to dynamically respond to unexpected tasks. This solution introduces a multi-dimensional priority evaluation mechanism, enabling rapid response to time-sensitive tasks such as search and rescue commands and reconnaissance, while simultaneously optimizing the dynamic allocation efficiency of satellite resources.

[0102] Through the above technical solutions, this application solves the problems of delayed response and rigid resource allocation in traditional SAR satellites under sudden mission scenarios. By using dynamic priority assessment and command queue management, it ensures that high-urgency and high-value targets are imaged first, reducing delays in critical mission execution. Simultaneously, by hierarchically storing guidance commands, it avoids low-priority tasks consuming computing resources, improving the operational efficiency of the onboard mission planning system.

[0103] In some embodiments, this application further proposes parsing the acquired AIS beacon signal of each ship to extract the ship characteristic attribute information and status information of each ship, including demodulating the AIS beacon signal and converting the radio frequency signal into a digital signal; decoding the digital signal according to a preset communication protocol to identify data frames; verifying the decoded data frames, discarding invalid data frames, and extracting the ship characteristic attribute information and status information of each ship from the valid data frames.

[0104] Demodulation refers to converting the received radio frequency signal into a baseband digital signal. This can be achieved using a quadrature demodulator in conjunction with an automatic gain control circuit, with carrier recovery and symbol synchronization techniques ensuring the accuracy of the signal conversion. Decoding refers to parsing the digital signal according to the AIS communication protocol. This can be achieved using the Viterbi decoding algorithm to process convolutionally coded data, combined with frame synchronization header detection to identify the data frame structure. Verification refers to verifying the integrity and correctness of the data frame. This can be achieved using a cyclic redundancy check (CRC) mechanism to automatically filter data frames with checksum errors or non-compliant formats. Ship characteristic attribute information includes the ship identification code, ship type, and size parameters. Status information includes real-time position, speed, and heading. This can be obtained by parsing the corresponding fields in the AIS data message, using a message structure parser to extract the binary data of preset fields and convert it into a readable format.

[0105] Specifically, in ship monitoring missions, the satellite first acquires radio frequency signals via an AIS receiver. After bandpass filtering and amplification, the signals are sent to the demodulation module. The demodulated digital bitstream enters the decoding unit, where it is parsed according to the frame structure specified in the AIS standard protocol to identify data frames containing ship information. Each data frame undergoes CRC verification; frames that fail the verification are immediately discarded, while valid frames that pass the verification proceed to the information extraction stage. The information extraction module extracts the ship's static characteristic parameters and dynamic navigation parameters from the data frames based on a pre-set field mapping table, forming structured data records. These structured data records are transmitted via a bus to the target screening module, providing a data foundation for subsequent ship matching and mission planning.

[0106] Compared to existing technologies, traditional AIS data processing methods typically parse the received raw data directly, lacking a rigorous verification mechanism, which allows erroneous data to potentially enter subsequent processing flows. Some existing solutions employ simple verification with fixed thresholds, which cannot effectively identify data frames with incorrect formats or abnormal content. This solution significantly improves data reliability through a multi-level verification mechanism combined with cyclic redundancy check and format specification checks. Furthermore, by employing a combination of protocol parsing and field mapping, it ensures compatibility between different AIS message formats, resolving the data parsing failure issue caused by protocol version differences in existing technologies.

[0107] Through the above technical solutions, this application effectively solves the problems of high bit error rate and information extraction errors caused by inconsistent data formats in the AIS signal parsing process. A rigorous verification mechanism reduces invalid data processing and lowers onboard computing resource consumption. The structured data extraction method improves the efficiency of subsequent target matching, ensuring the accurate acquisition of ship characteristic information and status parameters. The design, compatible with different protocol versions, enhances system adaptability and avoids monitoring blind spots caused by differences in AIS equipment.

[0108] In some embodiments, this application further proposes to acquire sea state data of the corresponding area of ​​at least one target to be imaged before controlling the SAR payload to perform imaging operations on the corresponding area of ​​at least one target to be imaged according to the imaging mission parameters, determine the current sea state level based on the sea state data, and adaptively adjust the parameters of the SAR payload based on the sea state level.

[0109] Sea state data refers to physical quantities reflecting the state of the ocean surface environment. Specifically, it can be obtained through real-time monitoring of sea surface wind speed, wind direction, and wave height parameters by spaceborne sensors, or by receiving sea surface meteorological information from ground-based meteorological departments via the BeiDou short message service. This data is used to assess the degree of environmental interference in the imaging area, providing a basis for subsequent parameter adjustments. The spaceborne sensor refers to a microwave radiometer or scatterometer installed on the satellite platform, specifically a Ku-band scatterometer, which retrieves sea surface wind speed and wave height parameters by measuring the sea surface backscattering coefficient. This feature is used to acquire real-time dynamic sea state information for the corresponding area of ​​at least one target to be imaged, addressing the problem of insufficient satellite autonomous sensing capabilities.

[0110] Specifically, the sea state data acquisition process is divided into two parallel channels: spaceborne monitoring and ground data reception. In the spaceborne monitoring channel, the microwave radiometer scans the target sea area at fixed time intervals, calculating sea surface wind speed parameters by measuring the microwave radiation energy emitted from the sea surface; the scatterometer transmits pulse signals and receives sea surface echoes, calculating wave height values ​​based on a model relating echo intensity and incident angle. In the ground data reception channel, the satellite receives encrypted sea state reports via the BeiDou short message module. These reports contain gridded sea state forecast information generated by meteorological departments from integrated multi-source observation data. The data acquired from both channels are formatted and input into the sea state assessment model to generate a fused sea state level determination result. When data is missing from the spaceborne sensors due to cloud cover or equipment failure, the system automatically switches to ground sea state data transmitted via BeiDou; when the BeiDou channel suffers from communication delays leading to insufficient data timeliness, the spaceborne real-time monitoring data is used preferentially.

[0111] In a specific implementation process, sea state classification refers to the quantitative grading of the marine environmental condition. It can be classified using internationally recognized standards such as the Dow Jones wave scale or Beaufort scale, for example, dividing sea states into four levels: calm, light, moderate, and severe. This classification provides a benchmark for adjusting SAR payload parameters, ensuring the adaptability of imaging parameters under different environmental conditions.

[0112] Adaptive adjustment of SAR payload parameters refers to dynamically configuring the radar system's operating parameters based on real-time environmental conditions. Specifically, this can be achieved by increasing the incident angle to reduce sea clutter interference, switching polarization modes to optimize target scattering characteristics, increasing the pulse repetition frequency to enhance the signal sampling rate, and adjusting the bandwidth to balance resolution and signal-to-noise ratio. This adjustment mechanism can specifically suppress the impact of sea state on imaging quality.

[0113] Specifically, before the satellite performs its imaging mission, the system uses onboard microwave radiometers and scatterometers to collect real-time sea surface wind speed and wave height data for the corresponding area of ​​at least one target to be imaged. Simultaneously, it receives forecast information from ground meteorological stations via BeiDou short message service. After fusing the measured and forecast data, the current sea state level is assessed using the Dow wave scale. When a severe sea state is determined, the imaging control unit automatically triggers parameter optimization algorithms, such as increasing the incident angle from the conventional 20 degrees to 35 degrees to reduce sea surface echo interference, and switching the polarization mode from HH to VV to improve the scattering intensity of ship targets. The adjusted parameters are then sent to the SAR payload via bus commands to ensure that it can still acquire effective imaging data under complex sea conditions.

[0114] Compared to existing technologies, traditional SAR satellite imaging systems lack integrated sea state awareness and parameter adaptation capabilities, often employing fixed imaging parameters in harsh marine environments, leading to decreased image signal-to-noise ratio and blurred target features. This proposed solution, however, effectively suppresses the interference of wave clutter on imaging quality through multi-source sea state data fusion and real-time parameter adjustment.

[0115] Through the above technical solution, this application solves the technical problem of SAR imaging quality degradation under severe sea states and achieves dynamic matching of imaging parameters with environmental conditions. This solution can automatically optimize radar operating modes under high sea state conditions, significantly improving the imaging clarity and feature identification of ship targets in complex marine environments, and providing reliable image data support for applications such as maritime search and rescue and monitoring of illegal vessels.

[0116] In a specific implementation, the aforementioned incident angle refers to the angle between the radar beam and the sea surface normal. This can be achieved by adjusting the beam pointing mechanism of the SAR payload. Increasing the incident angle reduces interference from sea clutter on the target echo signal. Polarization mode refers to the electromagnetic polarization of the radar beam. This can be achieved by switching between different polarization channels in the transceiver components. Selecting a polarization combination that matches the sea state enhances the contrast between the target and the background. Pulse repetition frequency refers to the time interval between radar pulses. This can be achieved by adjusting the radar timing controller parameters. Increasing the pulse repetition frequency increases the signal sampling rate, thus suppressing Doppler blurring caused by sea surface motion. Bandwidth refers to the frequency range of the radar signal. This can be achieved by adjusting the waveform generator parameters. Optimizing the bandwidth achieves a balance between resolution and signal-to-noise ratio.

[0117] Specifically, under severe sea conditions, the satellite first acquires sea surface wind speed data via its onboard microwave radiometer. When the wind speed exceeds a preset threshold, it is classified as a severe sea state. At this point, the SAR payload control unit automatically selects a parameter adjustment strategy. For example, it increases the incident angle from the usual 20 degrees to 35 degrees to reduce the impact of specular reflection from the sea surface, and simultaneously switches the polarization mode from HH to VV to enhance suppression of wave scattering. For fast-moving ship targets, the pulse repetition frequency is simultaneously increased to 1.5 times its original value to ensure the effectiveness of motion compensation. Regarding bandwidth adjustment, the optimal bandwidth value is automatically matched according to the current imaging mode. For example, in spotlight mode, the full bandwidth is maintained to preserve resolution, while in stripe mode, the bandwidth is appropriately reduced to improve the signal-to-noise ratio.

[0118] Compared to existing technologies, traditional SAR imaging systems use fixed parameter configurations, which cannot effectively suppress sea clutter interference in harsh sea conditions, resulting in blurred target features. This solution addresses the difficulty of target identification in complex marine environments through real-time sea state assessment and dynamic parameter adjustment.

[0119] Through the above technical solution, this application can effectively improve SAR image quality under severe sea conditions such as typhoons and strong waves, increasing the radar cross-section of ship targets by approximately 3 dB while reducing sea clutter background intensity by more than 40%. This adaptive adjustment mechanism ensures reliable identification of key targets in search and rescue missions, avoiding the risk of misjudgment due to degraded image quality.

[0120] In some embodiments, this application further proposes that when the sea state level is a preset severe sea state level, the SAR payload is controlled to perform multiple imaging operations on the corresponding area of ​​at least one target to be imaged to obtain multiple frames of raw SAR imaging data; the raw SAR imaging data of multiple frames is image registered and fused to generate SAR fused imaging data, and the first type of target imaging data and the second type of target imaging data are generated based on the SAR fused imaging data.

[0121] Among them, the severe sea state level refers to the degree of marine environmental severity determined by a comprehensive assessment of sea surface wind speed, wave height, or early warning information issued by meteorological departments. Specifically, a wind speed threshold exceeding 14 m / s or a wave height threshold exceeding 4 m can be used as the judgment criteria. Multiple imaging refers to performing SAR imaging operations twice or more consecutively within the corresponding area of ​​at least one target to be imaged. This can be achieved by adjusting satellite orbit parameters or attitude control to achieve repeated coverage. Image registration and fusion processing refers to geometrically aligning multiple SAR images with overlapping areas and then generating a composite image using pixel-level weighted averaging or feature extraction fusion algorithms. This can be achieved by combining feature point-based automatic registration algorithms with multi-scale decomposition and fusion methods.

[0122] Specifically, when the sea state level of at least one target area is detected to reach a preset level of severe conditions, the imaging control system automatically triggers multiple imaging modes. The SAR payload continuously captures images of the same sea area within a preset time interval, dynamically adjusting the incident angle and polarization mode according to the real-time sea state during each imaging session. After the acquired multiple frames of raw data are stored on-board, image offsets caused by wave motion are eliminated using a feature point matching algorithm, and random noise is suppressed using temporal coherent superposition technology. Finally, the processed multiple frames of data are fused to generate a high signal-to-noise ratio synthetic image. This synthetic image is compressed and divided into high-priority key information data and low-priority complete image data, which are transmitted back to the ground station through different communication channels.

[0123] In some specific implementations, a three-image sequence design can be adopted, with each image taken 2 seconds apart and the incident angles adjusted sequentially to 20 degrees, 25 degrees, and 30 degrees. During the image registration stage, sub-pixel alignment is achieved by extracting ship contour feature points. In the fusion processing, mean filtering is used for stationary targets, while a maximum value retention strategy is employed for moving targets. The fused image can improve the clarity of ship structural features by approximately 40% and reduce sea surface clutter interference by approximately 35%.

[0124] Compared to existing technologies, traditional SAR imaging systems typically acquire only a single, low-quality image in adverse sea conditions and lack compensation mechanisms for wave interference. This solution effectively overcomes the random errors of single-shot imaging through multi-angle continuous imaging and intelligent fusion processing, enabling the ship target identification accuracy to remain above 85% even in sea state 6.

[0125] Through the above technical solution, this application solves the problem of target identification difficulties caused by the degradation of SAR image quality in harsh marine environments, and effectively improves the accuracy of ship monitoring under complex sea conditions. Multi-frame data fusion processing significantly suppresses image blurring and noise interference caused by sea waves, enabling key ship features to be clearly presented in the synthesized image, providing reliable image data support for maritime search and rescue and surveillance.

[0126] In a specific implementation, the process of AIS beacon-guided SAR satellite imaging with BeiDou short message service provided by the invention embodiment can be as follows: First, the satellite continuously receives AIS beacon signals and performs preprocessing during operation. Then, the preprocessed AIS information is analyzed to identify target ships and predict their entry time and location into the imaging area. Target ship commands can be transmitted to the satellite via both ground station and BeiDou short message channels. Next, the satellite's integrated electronic module controls the satellite imaging equipment according to the target guidance commands, completing imaging and data storage. The raw echo data of the SAR payload imaging is stored in the solid-state memory of the data transmission unit. When the satellite enters the ground station's visible arc, it is transmitted to the ground station in order of mission priority number. Emergency imaging tasks can be processed in real time by the onboard imaging processing payload to generate a concise summary report, which is then sent to the ground station via the BeiDou short message terminal. Finally, the ground receiving and processing center receives the imaging data and AIS guidance information, performs a series of processing steps, and generates a ship monitoring report.

[0127] Based on the same general inventive concept, this invention also protects an AIS beacon-guided SAR satellite imaging system that integrates BeiDou short messages. The AIS beacon-guided SAR satellite imaging system that integrates BeiDou short messages provided by this invention will be described below. The AIS beacon-guided SAR satellite imaging system that integrates BeiDou short messages described below can be referred to in correspondence with the AIS beacon-guided SAR satellite imaging method that integrates BeiDou short messages described above.

[0128] Figure 2 This is a schematic diagram of the structure of the AIS beacon-guided SAR satellite imaging system fused with BeiDou short messages provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the AIS beacon-guided SAR satellite imaging system integrating BeiDou short message service in this embodiment includes a BeiDou short message transceiver module, an AIS beacon parsing module, a satellite integrated electronic module, an on-board imaging processing module, and an integrated SAR payload and data transmission and storage module.

[0129] The BeiDou short message transceiver module is used to receive target imaging instructions sent by a ground terminal through the BeiDou short message transceiver channel; the target imaging instructions include target identification information.

[0130] The AIS beacon parsing module is used to parse the acquired AIS beacon signals of each ship, extract the ship characteristic attribute information and status information of each ship; and match the ship characteristic attribute information of each ship with the target identification information to filter out at least one target ship.

[0131] The on-board imaging processing module is used to perform on-board autonomous mission planning based on the status information and the satellite's own orbital parameters, select at least one target to be imaged from the at least one target ship, and generate imaging mission parameters.

[0132] The SAR payload and data transmission / storage integrated module is used to control the SAR payload to perform imaging operations on the corresponding area of ​​the at least one target to be imaged according to the imaging task parameters, generating raw SAR imaging data; and to process the raw SAR imaging data to obtain first-type target imaging data and second-type target imaging data, and to transmit the first-type target imaging data back to the ground terminal through the BeiDou short message transceiver channel, and transmit the second-type target imaging data back to the ground terminal through a conventional data transceiver channel, wherein the first-type target imaging data has a higher priority than the second-type target imaging data.

[0133] After receiving the data, the ground terminal can send parameter adjustment commands (such as "increase the resolution to 0.3m") via BeiDou, and the satellite will dynamically update the imaging template library.

[0134] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. The electronic device may include: a processor 310, a communication interface 320, a memory 330, and a communication bus 340. The processor 310, communication interface 320, and memory 330 communicate with each other via the communication bus 340. The processor 310 can call logical instructions stored in the memory 330 to execute an AIS beacon-guided SAR satellite imaging method that integrates BeiDou short message service.

[0135] Furthermore, the logical instructions in the aforementioned memory 330 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0136] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the AIS beacon-guided SAR satellite imaging method that integrates BeiDou short messages provided by the above methods.

[0137] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, is implemented to perform the AIS beacon-guided SAR satellite imaging method fused with BeiDou short messages provided by the above methods.

[0138] It should be noted that all relevant information that may be involved in the various embodiments of the present invention is processed in strict accordance with the requirements of laws and regulations, following the principles of legality, legitimacy, and necessity, based on the reasonable purpose of the business scenario, and is information that users actively provide or generate during the use of the product / service, as well as information obtained with user authorization.

[0139] The information processed by this invention may vary depending on the specific product / service scenario and should be based on the specific scenario in which the user uses the product / service. This may involve user account information, device information, or other related information. This invention will treat the relevant information and its processing with the utmost diligence.

[0140] This invention places great importance on the security of related information and has adopted reasonable and feasible security protection measures that comply with industry standards to protect related information and prevent unauthorized access, public disclosure, use, modification, damage or loss of related information.

[0141] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0142] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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; and these 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 the present invention.

Claims

1. A method for guiding SAR satellite imaging by fusing Beidou short message and AIS beacon, characterized in that, include: The system receives target imaging commands sent by a ground terminal via the BeiDou short message transceiver channel; the target imaging commands include target identification information. The AIS beacon signals of each vessel are analyzed to extract the vessel's characteristic attributes and status information. The ship characteristic attribute information of each ship is matched with the target identification information to filter out at least one target ship; Based on the state information and the satellite's own orbital parameters, on-board autonomous mission planning is performed, at least one target to be imaged is selected from the at least one target ship, and imaging mission parameters are generated. Based on the imaging task parameters, the SAR payload is controlled to perform imaging operations on the corresponding area of ​​the at least one target to be imaged, generating raw SAR imaging data. The raw SAR imaging data is processed to obtain first-type target imaging data and second-type target imaging data. The first-type target imaging data is transmitted back to the ground terminal through the BeiDou short message transceiver channel, and the second-type target imaging data is transmitted back to the ground terminal through the conventional data transceiver channel. The first-type target imaging data has a higher priority than the second-type target imaging data.

2. The AIS beacon-guided SAR satellite imaging method integrating BeiDou short messages as described in claim 1, characterized in that, The target imaging command also includes imaging requirement information; Based on the aforementioned state information and the satellite's own orbital parameters, on-board autonomous mission planning is performed, selecting at least one target to be imaged from the at least one target vessel, and generating imaging mission parameters, including: Using a kinematic model, based on the state information and the satellite's own orbital parameters, the motion trajectory of the at least one target vessel is predicted; The target ship corresponding to the motion trajectory that enters the imaging coverage of the SAR payload is taken as the target to be imaged, and the imaging window time is generated based on the time when the motion trajectory enters and exits the imaging coverage of the SAR payload. Based on the imaging window time, the motion trajectory of the target to be imaged, and the imaging requirement information, the imaging task parameters are generated; wherein, the imaging task parameters include satellite attitude parameters and imaging mode parameters.

3. The AIS beacon-guided SAR satellite imaging method integrating BeiDou short messages according to claim 2, characterized in that, Based on the imaging task parameters, the SAR payload is controlled to perform imaging operations on the corresponding region of the at least one target to be imaged, generating raw SAR imaging data, including: At a preset first time point before the imaging window arrives, satellite attitude adjustment is triggered to meet the satellite attitude parameters. At a preset second time point before the imaging window arrives, the SAR payload is controlled to power on and warm up. During the imaging window, the SAR payload is controlled to call an imaging mode template that matches the imaging mode parameters, perform imaging operations, and generate raw SAR imaging data.

4. The method of claim 3, wherein the method further comprises: Triggering satellite attitude adjustment to meet the stated satellite attitude parameters includes: Based on the imaging requirements and the ship characteristic attributes of the target to be imaged, calculate the roll angle required for satellite attitude maneuvering and the yaw guidance angle used to compensate for Earth's rotation. The control reaction flywheel drives the SAR satellite to perform a roll maneuver, and the star sensor is used to perform closed-loop control of the satellite attitude until the attitude is stabilized in the required imaging attitude of the satellite attitude parameters.

5. The method of claim 3, wherein the method further comprises: The target imaging command also includes the mission urgency and target importance; Before generating raw SAR imaging data, the process includes controlling the SAR payload to perform imaging operations on the corresponding region of the at least one target to be imaged, based on the imaging task parameters, and further includes: Based on the urgency of the task, the importance of the target, and the status information of the at least one target to be imaged, the imaging priority of the at least one target to be imaged is determined; Generate target guidance instructions for the at least one target to be imaged, and store the target guidance instructions for the at least one target to be imaged into the target guidance instructions for the at least one target to be imaged according to the imaging priority of the at least one target to be imaged.

6. The method of claim 1, wherein the method further comprises: The acquired AIS beacon signals of each vessel are parsed to extract the vessel's characteristic attribute information and status information, including: The AIS beacon signal is demodulated to convert the radio frequency signal into a digital signal; The digital signal is decoded according to a preset communication protocol to identify data frames; The decoded data frames are verified, invalid data frames are discarded, and ship characteristic attribute information and status information of each ship are extracted from the valid data frames.

7. The method of claim 1-6, wherein the method further comprises, Before generating raw SAR imaging data, the process includes controlling the SAR payload to perform imaging operations on the corresponding region of the at least one target to be imaged, based on the imaging task parameters, and further includes: Acquire sea state data for the corresponding area of ​​at least one target to be imaged; Based on the sea state data, determine the current sea state level; Based on the sea state level, the parameters of the SAR payload are adaptively adjusted.

8. The method according to claim 7, wherein the method further comprises the step of: Based on the sea state level, the parameters of the SAR payload are adaptively adjusted, including: When the sea state level is a preset severe sea state level, at least one of the following is used: increasing the incident angle of the SAR payload, adjusting the polarization mode, increasing the pulse repetition frequency, and adjusting the bandwidth.

9. The AIS beacon-guided SAR satellite imaging method integrating BeiDou short messages according to claim 7, characterized in that, Also includes: When the sea state level is a preset severe sea state level, the SAR payload is controlled to perform multiple imaging operations on the corresponding area of ​​the at least one target to be imaged, thereby acquiring multiple frames of raw SAR imaging data. The multi-frame SAR raw imaging data is subjected to image registration and fusion processing to generate SAR fused imaging data, and the first type of target imaging data and the second type of target imaging data are generated based on the SAR fused imaging data.

10. The method of claim 7, wherein the method further comprises: Acquire sea state data for the corresponding area of ​​at least one target to be imaged, including: The system acquires at least one type of sea state data, including wind speed, wind direction, and wave height, through real-time monitoring using onboard sensors; and / or receives sea state data released by ground meteorological departments through the BeiDou short message transceiver channel.

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