Satellite-borne synthetic aperture radar in-orbit autonomous task planning method, device and equipment

Abstract

The invention relates to the technical field of spaceflight microwave remote sensing, and provides a spaceborne synthetic aperture radar in-orbit autonomous task planning method, device and equipment, and the method comprises the steps: obtaining imaging parameter information; the imaging parameter information is determined by the satellite imaging system based on task annotation information, orbit information and an imaging parameter preset table, and the task annotation information is obtained by the satellite imaging system by analyzing observation requirements of a user; the orbit information is determined based on satellite forecast information. According to the method, imaging parameter information is determined by a satellite imaging system based on task uploading information, orbit information and an imaging parameter preset table, partial parameter calculation and instruction generation processes of traditional satellite-borne SAR task planning are moved to a satellite, manual calculation and ground uploading steps are omitted, and dependence of the task planning process on ground calculation is reduced; the task uploading information is obtained by analyzing the observation demand of the user through the satellite imaging system, the observation demand can be uploaded in advance, satellite resources are fully utilized, and the task execution efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of aerospace microwave remote sensing technology, and in particular to an on-orbit autonomous mission planning method, device and equipment for a spaceborne synthetic aperture radar. Background Art

[0002] Traditional spaceborne Synthetic Aperture Radar (SAR) mission planning methods have limited adaptability during satellite orbit adjustments or complex mission environments. Because traditional spaceborne SAR mission planning methods are complex and time-consuming, requiring significant lead time to prepare parameters, they rely heavily on orbit prediction information from ground systems. However, the accuracy of orbit prediction information can be significantly compromised during satellite orbit adjustments or in complex and changing mission scenarios. Due to inaccurate orbital information, calculated observation parameters (such as beam position and imaging time) can deviate from actual requirements, directly impacting imaging quality and effectiveness.

[0003] Moreover, the method has a complex operational process and consumes a lot of manpower and material resources. The traditional method requires manual completion of multiple ground steps such as orbit prediction, parameter calculation, command generation, and ground annotation. The operational process is cumbersome, not only inefficient, but also increases labor and time costs. Ground annotation depends on the time of passing the station, and there is a risk of annotation failure and inability to observe in time. Ground annotation can only be carried out when the satellite passes the station, but the satellite's passing time is limited and uncontrollable. If the annotation cannot be completed within the scheduled time, the observation command will not be transmitted to the satellite in time, resulting in the mission not being able to be executed on time.

[0004] Traditional methods lack flexibility and are difficult to adapt to dynamic mission requirements. They require advance mission planning and cannot dynamically adjust to real-time orbital information or unexpected mission demands. When faced with complex and ever-changing mission scenarios such as emergency observation, their flexibility is clearly insufficient, making it difficult to meet the urgent need for rapid response. If mission execution is hindered, the entire planning process must be restarted, increasing the difficulty and cost of planning and execution. Summary of the Invention

[0005] The present invention provides a method, device and equipment for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar, which are used to solve the defects of the traditional spaceborne synthetic aperture radar mission planning method in the prior art.

[0006] The present invention provides an on-orbit autonomous mission planning method for a spaceborne synthetic aperture radar, comprising the following steps: Acquiring imaging parameter information; the imaging parameter information is determined by the satellite imaging system based on mission annotation information, orbit information, and an imaging parameter preset table, wherein the mission annotation information is obtained by the satellite imaging system through analysis of the user's observation requirements; the orbit information is determined based on satellite forecast information, and the imaging parameter preset table is used to reflect the imaging parameters set by the satellite imaging system under different conditions; the imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode; Determining wave position imaging parameters based on the orbit altitude, the downward viewing angle, the imaging mode, and the preset imaging parameter table, and determining gain control parameters based on the polarization mode and the target type; Determining a proximal slant distance and a distal slant distance of the wave position based on the viewing angle range of the wave position in the wave position imaging parameters, determining a sampling start based on the proximal slant distance, determining a sampling duration based on the proximal slant distance and the distal slant distance of the wave position, and determining imaging information corresponding to the imaging mode; Spaceborne synthetic aperture radar imaging is performed based on the wave position imaging parameter, the gain control parameter, the sampling start, the sampling duration and the imaging information.

[0007] According to a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar provided by the present invention, determining imaging information corresponding to the imaging mode includes: When the imaging mode is a spotlight mode or a stripe mode, determining a first number of pulses based on an imaging duration and a pulse repetition frequency of the target position, and using the first number of pulses as the imaging information; When the imaging mode is a scanning mode, the second number of pulses is determined based on the imaging duration of each sub-band and the pulse repetition frequency, and the number of beam scans is determined based on the imaging duration and the scanning mode sub-band cycle period, and the second number of pulses and the number of beam scans are used as the imaging information.

[0008] According to a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar provided by the present invention, the step of obtaining the preset imaging parameter table includes: Determine the orbit altitude relative to sea level based on orbit prediction information; determining a target maximum value of an equivalent orbit altitude based on the maximum value of the orbit altitude relative to sea level; determining a target minimum value of the equivalent orbit altitude based on the minimum value of the orbit altitude relative to sea level and the maximum value of the digital elevation of the ground, and determining an equivalent orbit altitude range based on the target maximum value and the target minimum value; Based on the equivalent orbit altitude range, the imaging parameter preset table is determined.

[0009] According to a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar provided by the present invention, determining the imaging parameter preset table based on the equivalent orbit altitude range includes: Determine the available range of pulse repetition frequencies for different imaging modes based on known platform parameters, known radar parameters, and different orbital altitudes; Determining a duty cycle of the pulse signal based on a platform power consumption constraint, and determining a pulse width based on the duty cycle; Determine a zebra pattern based on radar transmission timing and sub-satellite point constraints, determine a beam position based on the zebra pattern and radar beam width, and determine a pulse repetition frequency based on the beam position and an original imaging mode; Determine available parameters for all beam positions based on resolution, range ambiguity and azimuth ambiguity, noise equivalent backscatter coefficient, and data rate requirements; the available parameters include a viewing angle at the near end of the beam position, a viewing angle at the far end of the beam position, a viewing angle at the beam center, a pulse repetition frequency in the available range, the pulse width, bandwidth, sampling rate, sub-band imaging duration in a scanning mode, imaging duration in a beamforming mode, an original gain control parameter, and the equivalent orbit altitude range; Based on the available parameters, the imaging parameter preset table is determined.

[0010] According to a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar provided by the present invention, the method of determining the sampling start based on the proximal slant range includes: Determining the number of echo reception delay pulses based on the proximal slant range and the speed of light; The sampling start is determined based on the echo reception delay pulse number and the pulse repetition period.

[0011] According to an on-orbit autonomous mission planning method for a spaceborne synthetic aperture radar provided by the present invention, the determining of the sampling duration based on the proximal slant range and the distal slant range of the wave position comprises: The sampling duration is determined based on the far-end slant distance, the near-end slant distance, the pulse duration, and the sampling protection time interval.

[0012] According to a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar provided by the present invention, the mission annotation information includes the position coordinates of the target's location point, the target point's digital elevation value, the target point's ground feature type, resolution, polarization mode, and expected imaging time.

[0013] The present invention also provides an on-orbit autonomous mission planning device for a spaceborne synthetic aperture radar, comprising the following units: an acquisition unit configured to acquire imaging parameter information; the imaging parameter information is determined by the satellite imaging system based on mission annotation information, orbit information, and a preset imaging parameter table, wherein the mission annotation information is obtained by the satellite imaging system through analysis of a user's observation requirements; the orbit information is determined based on satellite forecast information, and the preset imaging parameter table is used to reflect imaging parameters set by the satellite imaging system under different conditions; the imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode; a first determining unit, configured to determine a wave position imaging parameter based on the orbit altitude, the downward viewing angle, the imaging mode, and the preset imaging parameter table, and to determine a gain control parameter based on the polarization mode and the target type; a second determining unit, configured to determine a proximal slant distance and a distal slant distance of the waveposition based on the viewing angle range of the waveposition in the waveposition imaging parameters, determine a sampling start based on the proximal slant distance, determine a sampling duration based on the proximal slant distance and the distal slant distance of the waveposition, and determine imaging information corresponding to the imaging mode; An imaging unit is used for performing spaceborne synthetic aperture radar imaging based on the wave position imaging parameters, the gain control parameters, the sampling start, the sampling duration and the imaging information.

[0014] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar as described above is implemented.

[0015] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar as described in any one of the above is implemented.

[0016] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-described methods for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar.

[0017] The present invention provides a method, device and equipment for autonomous on-orbit mission planning of a spaceborne synthetic aperture radar, which obtains imaging parameter information; the imaging parameter information is determined by a satellite imaging system based on mission annotation information, orbit information and an imaging parameter preset table, wherein the mission annotation information is obtained by the satellite imaging system through analysis of user observation requirements; the orbit information is determined based on satellite forecast information, and the imaging parameter preset table is used to reflect imaging parameters set by the satellite imaging system under different conditions; the imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type and imaging mode, and subsequent spaceborne synthetic aperture radar imaging is performed based on the imaging parameter information. On the one hand, the imaging parameter information is determined by the satellite imaging system based on the mission annotation information, orbit information and imaging parameter preset table, which moves some parameter calculation and instruction generation processes of traditional spaceborne SAR mission planning to the satellite, reducing the mission planning process's dependence on ground calculations and reducing manpower and material resources. On the other hand, the mission annotation information is obtained by the satellite imaging system through analysis of the user's observation needs, eliminating manual calculations and ground annotation steps, annotating observation needs in advance, making full use of satellite resources, greatly improving mission execution efficiency, and being able to quickly respond to dynamic observation needs, realize real-time parameter adjustment, meet diverse application scenarios, and enhance mission flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is one of the flow charts of the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the present invention.

[0020] Figure 2 This is a schematic diagram of the star-to-earth space geometry provided by the present invention.

[0021] Figure 3 It is a flowchart of step 240 in the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the present invention.

[0022] Figure 4 This is the second flow chart of the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the present invention.

[0023] Figure 5 The present invention provides a schematic structural diagram of an on-orbit autonomous mission planning device for a spaceborne synthetic aperture radar.

[0024] Figure 6It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0026] The terms "first," "second," and the like in the present invention are used to distinguish similar objects, and are not used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type.

[0027] In the existing technology, spaceborne synthetic aperture radar is an imaging radar that uses its relative motion with the target to achieve high-resolution observation. It has high-resolution, wide-band, all-day, all-weather, and global observation imaging capabilities, and has broad application prospects in military reconnaissance, disaster monitoring, resource surveys, and marine research.

[0028] SAR imaging mission planning plays a crucial role in the spaceborne SAR imaging process. It bridges the gap between the satellite platform, payload performance, and actual application requirements, and directly impacts the SAR system's ability to efficiently and accurately complete various observation missions. Mission planning not only determines the satellite's observation strategy, imaging mode, and control, but also profoundly influences the timeliness, resolution, and coverage of the observation data, further impacting subsequent data analysis and application effectiveness.

[0029] The operating procedures of traditional spaceborne SAR mission planning methods are complex, requiring manual orbit prediction, parameter calculation and command generation, which consumes a lot of manpower and material resources; traditional methods rely on ground systems to make orbit predictions in advance, especially in orbit adjustment or complex mission scenarios, the forecast information is inaccurate, resulting in deviations in the calculation of observation parameters, affecting imaging quality; and ground-based annotations rely on the time when the satellite passes the station, and there is a risk of not being able to be notified on time, which may result in the failure to execute the mission; at the same time, traditional methods lack flexibility and are difficult to adapt to dynamic mission requirements, especially in emergency observation scenarios; traditional methods have high mission execution risks, affecting overall efficiency.

[0030] With the enhancement of on-board computing and storage capabilities and the growing demand of users for flexibility, accuracy and ease of operation in spaceborne synthetic aperture radar (SAR) mission planning.

[0031] Based on the above problems, the present invention provides an on-orbit autonomous mission planning method for spaceborne synthetic aperture radar. Figure 1 This is one of the flow charts of the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the present invention, such as Figure 1 As shown, the method includes the following: Step 110: Acquire imaging parameter information. The imaging parameter information is determined by the satellite imaging system based on mission annotation information, orbit information, and a preset imaging parameter table. The mission annotation information is obtained by the satellite imaging system by analyzing the user's observation requirements. The orbit information is determined based on satellite forecast information. The preset imaging parameter table is used to reflect the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode.

[0032] Specifically, imaging parameter information can be obtained. This imaging parameter information is determined by the satellite imaging system based on mission information, orbit information, and a preset imaging parameter table. Mission information is derived from the satellite imaging system's analysis of the user's observation requirements. In other words, mission information refers to a series of instructions and parameters generated by the satellite imaging system based on the user's observation requirements, after system analysis and processing. These instructions and parameters are used to guide the satellite's on-orbit operation and the execution of the imaging mission.

[0033] Here, the observation requirements are analyzed to form a mission requirement package. This package is then uploaded to the satellite at an appropriate time, combining orbital predictions and ground station locations. This upload time can be adjusted flexibly, allowing mission requirements to be uploaded well in advance to ensure mission execution.

[0034] Here, the task annotation information includes the location coordinates of the target point, the digital elevation value of the target point, the target point's ground feature type, resolution, polarization mode, expected imaging time and imaging duration, etc., which are not specifically limited in the embodiment of the present invention.

[0035] The position coordinates of the target's location point may include the longitude, latitude, and altitude of the target's location point, and may also include the 84-coordinate system coordinates of the target point to be observed, etc., which is not specifically limited in the embodiment of the present invention.

[0036] The digital elevation value of a target point refers to the value of the target point in a digital elevation model (DEM). The feature type of a target point refers to the type of ground object at the target point. The feature types of a target point may include grassland, forest, desert, bare soil, ocean, city, etc., and are not specifically limited in this embodiment of the present invention.

[0037] Here, the resolution in the task annotation information can be replaced by the imaging mode. The polarization mode refers to the polarization mode of electromagnetic waves in radar imaging. The polarization mode can include horizontal polarization, vertical polarization, and cross polarization, etc. The embodiment of the present invention does not specifically limit this.

[0038] Here, the expected imaging time refers to the specific time point at which the user expects the satellite imaging system to perform imaging.

[0039] It should be noted that the expected imaging time and imaging duration in the mission information may include only one of them, two of them, or neither of them. If the mission information does not include both, imaging will be performed according to the appropriate time and default imaging duration planned autonomously on the satellite.

[0040] Orbital information is determined based on satellite forecasts. Orbital forecasts are crucial data for satellite operations management, providing precise information about a satellite's position and velocity at a specific point in time or time period. Orbital information reflects a satellite's position and motion at a specific time.

[0041] Here, the imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter preset table is pre-determined and stored in the satellite's storage unit for easy access during on-orbit mission planning. This process can be completed before the satellite is launched, or by utilizing the satellite information reconfiguration function to perform ground-based pre-setting and modification of the position information of the on-orbit satellite.

[0042] Among them, the imaging parameter information includes orbital altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type and imaging mode.

[0043] Here, orbital altitude refers to the vertical distance between the satellite's orbital plane and the Earth's surface when the satellite is in orbit. Polarization refers to the polarization of electromagnetic waves in radar imaging. Polarization modes can include horizontal polarization, vertical polarization, and cross polarization, and are not specifically limited in this embodiment of the present invention.

[0044] The target type refers to an object that needs to be observed and identified during satellite imaging. The target type can be a mountain, a river, a forest, a farmland, etc., and the embodiment of the present invention does not specifically limit this.

[0045] An imaging mode refers to a specific operating mode used by a satellite imaging system when acquiring images. Imaging modes may include strip mode, scanning mode, spotlight mode, etc., and are not specifically limited in the present embodiment.

[0046] It should be noted that the imaging parameter information is determined by selecting imaging parameters that match the mission information and orbit information from the imaging parameter preset table.

[0047] It is understandable that pre-registering observation requirements avoids mission failures due to delayed registration and significantly reduces mission execution risk. Furthermore, autonomous on-orbit mission planning utilizes orbital information closer to the imaging time, significantly improving the accuracy of imaging parameter calculations and ensuring mission reliability and imaging quality, especially during satellite orbit adjustments.

[0048] Here, the parameters that need to be calculated on-orbit include: the viewing angle below the target point, left / right viewing angle, satellite flight attitude (upward / inverted), equivalent orbital altitude at the imaging center, imaging time in seconds, imaging duration, millisecond time (first imaging indicates the exact imaging time, unit ms; non-first imaging indicates the relative time of imaging start time relative to the first imaging, unit 10ms), task serial number and imaging control word (master / slave selection and imaging times), etc.

[0049] Figure 2 This is a schematic diagram of the star-to-earth space geometry provided by the present invention. Indicates the near-end slant distance of the wave position, Indicates the far end slant distance of the wave position, Indicates the near-end downward viewing angle of the wave position, Indicates the viewing angle at the far end of the wave position. represents the far-end incident angle of the wave position, H represents the equivalent orbit height, and Re represents the earth radius of the target point. Figure 2 As shown in the figure, the downward viewing angle and the left and right side views of the target are calculated by the satellite platform based on the satellite position and the target position, through the satellite-ground geometric relationship and the satellite's flight direction; the forward and inverted flight marks are given by the satellite platform according to the current operating attitude.

[0050] The calculation method of the equivalent orbital altitude at the imaging center time is: given the satellite position (WGS84 coordinates) at the imaging center time, set it as: , the target point DEM is , the radius of the target point earth is , then the distance from the satellite to the center of the Earth is , the equivalent orbital height is .

[0051] Imaging time in seconds is the total number of seconds between 00:00:00 UTC on January 1, 2020, and the moment of radar imaging, expressed as an integer. For strip and sweep modes, the imaging time in seconds corresponds to the imaging start time; for spotlight mode, the imaging time in seconds is the overhead time minus 10 seconds.

[0052] Step 120 : determining wave position imaging parameters based on the orbit altitude, the downward viewing angle, the imaging mode, and the preset imaging parameter table, and determining gain control parameters based on the polarization mode and the target type.

[0053] Specifically, after obtaining the imaging parameter information, the wave position imaging parameters can be determined based on the orbital altitude, downward viewing angle, imaging mode, and imaging parameter preset table in the imaging parameter information. Specifically, based on the matching result between the imaging mode and the orbital altitude, a target parameter table can be selected from the imaging parameter preset table. Then, combined with the downward viewing angle parameters, the specific wave position in the target parameter table can be further located. Finally, the required imaging parameters are extracted from the corresponding wave position to obtain the wave position imaging parameters. The wave position imaging parameters mainly involve the beam pointing in radar imaging, the geometric relationship of the imaging area, and the parameter information of the imaging signal. It determines how the radar beam illuminates the target area, the imaging signal parameters, and how the echo signal is received.

[0054] Then, based on the polarization mode and target type, the gain control parameters are determined. Here, the gain control parameters are the MGC / AGC (Manual Gain Control / Automatic Gain Control) values.

[0055] Step 130: Determine the proximal slant distance and the distal slant distance of the waveposition based on the viewing angle range of the waveposition in the waveposition imaging parameters, determine the sampling start based on the proximal slant distance, determine the sampling duration based on the proximal slant distance and the distal slant distance of the waveposition, and determine the imaging information corresponding to the imaging mode.

[0056] Specifically, the near-end slant range and far-end slant range are determined based on the beamform imaging parameters. Furthermore, the sampling start is determined based on the near-end slant range, and the sampling duration is determined based on the near-end slant range and far-end slant range. The sampling start refers to the time when the radar system begins receiving echo signals from the target area. The sampling duration refers to the duration during which the radar system receives echo signals from the target area.

[0057] The near-end slant range is the straight-line distance between the radar antenna and the nearest end of the target's beam position. The far-end slant range is the straight-line distance between the radar antenna and the farthest end of the target's beam position.

[0058] Then, imaging information corresponding to the imaging mode is determined, where different imaging modes correspond to different imaging information.

[0059] Step 140 : Perform spaceborne synthetic aperture radar imaging based on the wave position imaging parameter, the gain control parameter, the sampling start, the sampling duration, and the imaging information.

[0060] Specifically, after obtaining the gain control parameters, the SAR payload's transmit pulse signal parameters (bandwidth, pulse width, and pulse repetition frequency) and receive signal sampling rate can be configured based on the beamform imaging parameters. The sampling window parameters for the mission's receive phase are set based on the sampling parameter calculation results (including the sampling start time and duration). The receive gain control mode and initial gain value are determined in conjunction with the gain control parameters. The satellite's roll direction is planned based on the left and right side-view analysis results, and the SAR payload antenna's two-dimensional scanning strategy is designed based on the beamform center's viewing angle and azimuth scanning angle. Furthermore, the SAR payload's operating mode (including the transmit and receive polarization channel switching states, the specific SAR operating mechanism, and data labeling rules) is determined based on the polarization mode and imaging mode (e.g., stripe mode, spotlight mode, or scanning mode) in the imaging parameters. Ultimately, by combining the above parameter configurations with the imaging mission requirements, the spaceborne synthetic aperture radar mission is completed. Polarization modes include HH (Horizontal-Horizontal), HV (Horizontal-Vertical), VH (Vertical-Horizontal), and VV (Vertical-Vertical), but are not specifically limited in this embodiment of the present invention.

[0061] The method provided by an embodiment of the present invention obtains imaging parameter information; the imaging parameter information is determined by a satellite imaging system based on mission annotation information, orbit information, and an imaging parameter preset table. The mission annotation information is obtained by the satellite imaging system through analysis of user observation requirements; the orbit information is determined based on satellite forecast information, and the imaging parameter preset table is used to reflect the imaging parameters set by the satellite imaging system under different conditions; the imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode, and subsequent spaceborne synthetic aperture radar imaging is performed based on the imaging parameter information. On the one hand, the imaging parameter information is determined by the satellite imaging system based on the mission annotation information, orbit information and imaging parameter preset table, and some parameter calculation and instruction generation processes of traditional spaceborne SAR mission planning are moved to the satellite, which reduces the mission planning process's dependence on ground calculations, reduces manpower and material resources, and eliminates manual calculations and ground annotation steps; on the other hand, the mission annotation information is obtained by the satellite imaging system through analysis of the user's observation needs, annotating observation needs in advance, making full use of satellite resources, greatly improving mission execution efficiency, and being able to quickly respond to dynamic observation needs, realize real-time parameter adjustment, meet diverse application scenarios, and enhance mission flexibility.

[0062] Based on the above embodiment, determining the imaging information corresponding to the imaging mode in step 130 includes: Step 131, when the imaging mode is a spotlight mode or a stripe mode, determining a first pulse number based on the imaging duration and pulse repetition frequency of the target position, and using the first pulse number as the imaging information; Step 132, when the imaging mode is a scanning mode, determine the second number of pulses based on the imaging duration of each sub-band and the pulse repetition frequency, and determine the number of beam scans based on the imaging duration and the scanning mode sub-band cycle period, and use the second number of pulses and the number of beam scans as the imaging information.

[0063] Specifically, when the imaging mode is the spotlight mode or the stripe mode, the first pulse number is determined based on the imaging duration and the pulse repetition frequency of the target position, and the first pulse number is used as the imaging information.

[0064] Here, the formula for the number of first pulses is as follows: in, Indicates the number of the first pulse, represents the pulse repetition frequency, Indicates the imaging duration of the target's location.

[0065] When the imaging mode is a scanning mode, the number of second pulses is determined based on the imaging duration and pulse repetition frequency of each sub-band, and the number of beam scans is determined based on the imaging duration and the scanning mode sub-band cycle period, and the number of second pulses and the number of beam scans are used as imaging information.

[0066] Here, the formula for the second pulse number is as follows: in, Indicates the number of second pulses, represents the pulse repetition frequency, Indicates the imaging duration of each sub-band.

[0067] Here, based on the imaging duration and the scanning mode sub-band cycle period, the formula for determining the number of beam scans (the number of burst cycles) is: in, Indicates the number of beam scans, Indicates the imaging duration of the target’s location point, Indicates the scanning mode subband cycle period.

[0068] It should be noted that the imaging time of the scanning mode should be An integer multiple of .

[0069] Based on the above embodiment, the step of obtaining the preset imaging parameter table includes: Step 210: determining the orbit altitude relative to sea level based on the orbit prediction information; Step 220: determining a target maximum value of an equivalent orbital altitude based on the maximum value of the orbital altitude relative to sea level; Step 230: determining a target minimum value of the equivalent orbit altitude based on the minimum value of the orbit altitude relative to sea level and the maximum value of the digital elevation of the ground, and determining an equivalent orbit altitude range based on the target maximum value and the target minimum value; Step 240: Determine the preset imaging parameter table based on the equivalent orbit altitude range.

[0070] Specifically, based on the orbit prediction information, the orbit height relative to the sea level is determined. The orbit height relative to the sea level can be expressed as express.

[0071] Based on the orbital prediction information, the satellite's orbital altitude relative to sea level at a specific time can be determined. This requires converting the satellite's position from an Earth-centered, Earth-fixed coordinate system to an Earth-centered, Earth-horizontal coordinate system, then calculating the distance between the satellite and the center of the Earth. Finally, subtracting the Earth's radius from the distance to obtain the orbital altitude relative to sea level.

[0072] Then, the maximum value of the orbital altitude relative to sea level can be calculated based on the ), determine the target maximum value of the equivalent orbit altitude.

[0073] Furthermore, a target minimum value of the equivalent track altitude can be determined based on the minimum value of the track altitude relative to sea level and the maximum value of the digital elevation of the ground. Here, the target minimum value of the equivalent track altitude is the minimum value of the track altitude relative to sea level minus the maximum value of the digital elevation DEM of the ground.

[0074] Finally, based on the target maximum value and the target minimum value, the equivalent orbit height range is determined, and based on the equivalent orbit height range, the imaging parameter preset table is determined.

[0075] Based on the above embodiments, Figure 3 240 in the on-orbit autonomous mission planning method for a spaceborne synthetic aperture radar provided by the present invention. Figure 3 As shown, step 240 includes: Step 241 , determining available ranges of pulse repetition frequencies for different imaging modes based on known platform parameters, known radar parameters, and different orbital altitudes; Step 242 , determining a duty cycle of the pulse signal based on the platform power consumption constraint, and determining a pulse width based on the duty cycle; Step 243: determining a zebra pattern based on the radar transmission timing and the constraints of the sub-satellite point, determining a beam position based on the zebra pattern and the width of the radar beam, and determining a pulse repetition frequency based on the beam position and the original imaging mode; Step 244, based on the resolution, range ambiguity and azimuth ambiguity, noise equivalent backscatter coefficient and data rate requirements, determine the available parameters of all beam positions; the available parameters include the viewing angle at the near end of the beam position, the viewing angle at the far end of the beam position, the viewing angle at the beam center, the pulse repetition frequency in the available range, the pulse width, bandwidth, sampling rate, sub-band imaging time of the scanning mode, imaging time of the beam-forming mode, original gain control parameters and the equivalent orbit altitude range.

[0076] Step 245: Determine the preset imaging parameter table based on the available parameters.

[0077] Specifically, based on known platform parameters, known radar parameters, and different orbital altitudes, the available ranges of pulse repetition frequencies for different imaging modes are determined. Here, known platform parameters include the satellite platform's speed and altitude, and known radar parameters include the radar's operating frequency, wavelength, antenna length, and other parameters. These are not specifically limited in this embodiment of the present invention.

[0078] Then, based on the platform power consumption constraint, the duty cycle of the pulse signal is determined, and based on the duty cycle, the pulse width is determined. That is, under the platform power consumption constraint, the duty cycle D of the pulse signal is determined, and the duty cycle is the pulse width. T on and the entire cycle time T The ratio of T=T on+ T off , T off is the pulse interval time.

[0079] The pulse width is obtained by multiplying the duty cycle by the entire cycle time.

[0080] Furthermore, a zebra pattern can be determined based on the radar transmission timing and the constraints of the sub-satellite point.

[0081] The radar transmit timing is determined by the radar's pulse width, pulse repetition period, and the time between the leading and trailing edges of the target echo. To ensure complete echo reception, the target echo signal's leading edge must be greater than the trailing edge of the previous transmitted pulse and less than the leading edge of the next pulse. The sub-satellite point constraints are determined based on the satellite orbit parameters, pulse repetition frequency (PRF), sub-satellite point echo width, and the leading and trailing edge times of the target echo signal. To avoid the influence of sub-satellite point echoes, the leading edge of the target echo signal must be greater than the trailing edge of the previous sub-satellite point echo and less than the leading edge of the next sub-satellite point echo. The radar transmit timing constraints are combined with the sub-satellite point constraints to generate a zebra plot. A zebra plot is a two-dimensional chart with the PRF value on the horizontal axis and the lower viewing angle on the vertical axis. Different colors or lines represent the timing of the radar pulse's transmit cutoff and sub-satellite point echo window.

[0082] Then, the beam position division is determined based on the radar observation width and the overlap width between beam positions. The beam position refers to the projected position of the radar beam on the ground.

[0083] Furthermore, based on the divided wave positions and zebra diagram constraints, the pulse repetition frequency that meets the transmission and reception timing requirements and the sub-satellite point timing requirements is determined.

[0084] Finally, based on the resolution, range ambiguity and azimuth ambiguity, noise equivalent backscatter coefficient and data rate requirements, the available parameters of all beam positions are determined, among which the available parameters include the viewing angle at the near end of the beam position, the viewing angle at the far end of the beam position, the viewing angle at the beam center, pulse repetition frequency, pulse width, bandwidth, sampling rate, sub-band imaging time of scanning mode, imaging time of beamforming mode, original gain control parameters and equivalent orbit altitude range.

[0085] Here, range ambiguity refers to the fact that, due to the radar's pulse repetition frequency (PRF), echo signals from other regions delayed by an integer number of pulse repetition periods from the imaging band enter the receiver through the antenna sidelobes, resulting in overlap in the range direction and making it impossible to distinguish targets. Azimuth ambiguity refers to the fact that Doppler signals above the PRF, after sampling, fold into the processing bandwidth of the center of the azimuth spectrum, causing aliasing in the azimuth spectrum and making it impossible to distinguish targets.

[0086] The noise equivalent backscatter coefficient is a key parameter for measuring the radiometric resolution or system sensitivity in synthetic aperture radar systems. It represents the minimum backscatter intensity ( ), which is the backscatter coefficient value when the target echo power equals the system noise power. The lower the value, the stronger the radar system's detection capability (higher sensitivity) for weakly scattering targets.

[0087] The data rate requirement refers to the amount of data that the radar system needs to process, which is usually determined by factors such as imaging mode, bandwidth, sampling rate, etc. The data rate requirement determines the radar system's ability to process and transmit data.

[0088] It should be noted that the available parameters of all wave positions need to meet the requirements of resolution, range ambiguity and azimuth ambiguity, noise equivalent backscatter coefficient and data rate.

[0089] Finally, based on the available parameters, the preset imaging parameter table is determined. In order to obtain a wave position information table covering all orbital altitudes, the equivalent orbital altitude needs to be divided, and then the above process is iterated according to different orbital altitudes to generate multiple sets of wave position information tables.

[0090] Based on the above embodiment, determining the sampling start based on the near-end slant distance in step 130 includes: Step 130-1, determining the number of echo reception delay pulses based on the near-end slant range and the speed of light; Step 130 - 2 : Determine the sampling start based on the echo reception delay pulse number and the pulse repetition period.

[0091] Specifically, based on the near-end slant range and the speed of light, the number of echo reception delay pulses is determined using the following formula: in, Indicates the number of echo reception delay pulses, represents the near end slant distance, represents the speed of light, Express Round down, Indicates the pulse repetition period.

[0092] Then, based on the echo reception delay pulse number and the pulse repetition period, the sampling start is determined using the following formula: in, Indicates the start of sampling, Indicates the number of echo reception delay pulses, represents the near end slant distance, represents the speed of light, Indicates the pulse repetition period.

[0093] Based on the above embodiment, determining the sampling duration based on the near-end slant distance and the far-end slant distance in step 130 includes: The sampling duration is determined based on the far-end slant distance, the near-end slant distance, the pulse duration, and the sampling protection time interval.

[0094] Specifically, the sampling duration is determined based on the far-end slant distance, near-end slant distance, pulse duration, and sampling protection time interval. The formula is as follows: in, Indicates the sampling duration, Indicates the far end slant distance of the wave position, represents the near end slant distance, Indicates the pulse width, Indicates the sampling protection time interval, Represents the speed of light.

[0095] It should be noted that The sampling duration of one frame.

[0096] Based on any of the above embodiments, Figure 4 This is the second flow chart of the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the present invention, such as Figure 4 As shown, the method includes the following steps: Step 1: Establishment of preset imaging parameter tables: Considering the changes in the earth radius, orbit altitude, and target point digital elevation model values, the imaging parameter tables of different modes and altitudes are calculated according to the imaging parameter constraints.

[0097] Step 2, imaging parameter preset: preset the calculated imaging parameter information table into the satellite storage unit. This step can support satellite on-orbit updates.

[0098] Step 3: Clarify user observation requirements: Determine the location coordinates of the observation target point, the DEM of the target point, the target object type, resolution, polarization mode, and expected imaging time based on the observation requirements.

[0099] Step 4, mission requirements annotation: The information specified in step 3 is packaged on the ground and annotated to the satellite with the help of the ground station.

[0100] Step 5, satellite parameter calculation and transmission: The satellite calculates the equivalent orbital altitude of the target, the downward viewing angle of the target point and the satellite position at the time of satellite passing according to the mission information and orbit information, and then transmits the calculated data to the SAR payload.

[0101] Step 6, SAR payload parameter calculation and imaging: Based on the information received in step 5, the payload obtains the wave position parameters and MGC values ​​by table lookup, obtains the sampling start and beamforming mode imaging start time and other parameters by calculation, and then performs imaging based on the parameters obtained by table lookup and calculated parameters.

[0102] The method provided by the embodiments of the present invention moves some of the parameter calculation and command generation processes of traditional spaceborne SAR mission planning to the satellite, reducing the mission planning process's reliance on ground-based computing. Furthermore, the present invention provides a method and process for implementing autonomous on-orbit spaceborne SAR mission planning, enabling on-orbit implementation of spaceborne SAR mission planning based on existing SAR satellite system designs.

[0103] The following describes the on-orbit autonomous mission planning device for a spaceborne synthetic aperture radar provided by the present invention. The on-orbit autonomous mission planning device for a spaceborne synthetic aperture radar described below and the on-orbit autonomous mission planning method for a spaceborne synthetic aperture radar described above can be referenced to each other.

[0104] Based on any of the above embodiments, the present invention provides an on-orbit autonomous mission planning device for a spaceborne synthetic aperture radar. Figure 5 FIG. 1 is a schematic diagram of the structure of the on-orbit autonomous mission planning device for a spaceborne synthetic aperture radar provided by the present invention. Figure 5 As shown, the device includes: An acquisition unit 510 is configured to acquire imaging parameter information; the imaging parameter information is determined by the satellite imaging system based on mission annotation information, orbit information, and a preset imaging parameter table. The mission annotation information is obtained by the satellite imaging system by analyzing the user's observation requirements. The orbit information is determined based on satellite forecast information. The preset imaging parameter table is used to reflect the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode. A first determining unit 520 is configured to determine a wave position imaging parameter based on the orbit altitude, the downward viewing angle, the imaging mode, and the preset imaging parameter table, and to determine a gain control parameter based on the polarization mode and the target type; A second determining unit 530 is configured to determine a proximal slant distance and a distal slant distance of the waveposition based on the viewing angle range of the waveposition in the waveposition imaging parameters, determine a sampling start based on the proximal slant distance, determine a sampling duration based on the proximal slant distance and the distal slant distance of the waveposition, and determine imaging information corresponding to the imaging mode; The imaging unit 540 is configured to perform spaceborne synthetic aperture radar imaging based on the wave position imaging parameter, the gain control parameter, the sampling start, the sampling duration, and the imaging information.

[0105] An apparatus provided in an embodiment of the present invention acquires imaging parameter information. The imaging parameter information is determined by a satellite imaging system based on mission annotation information, orbit information, and an imaging parameter preset table. The mission annotation information is obtained by the satellite imaging system through analysis of a user's observation requirements. The orbit information is determined based on satellite forecast information, and the imaging parameter preset table is used to reflect the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode. Subsequent spaceborne synthetic aperture radar imaging is then performed based on the imaging parameter information. On the one hand, the imaging parameter information is determined by the satellite imaging system based on the mission annotation information, orbit information, and the imaging parameter preset table. This moves some parameter calculation and instruction generation processes of traditional spaceborne SAR mission planning to the satellite, reducing the mission planning process's reliance on ground-based calculations, eliminating manual calculations and ground-based annotation steps, and reducing human and material resources. On the other hand, the mission annotation information is obtained by the satellite imaging system through analysis of the user's observation requirements. Pre-annotating observation requirements fully utilizes satellite resources, significantly improving mission execution efficiency, and enabling rapid response to dynamic observation requirements, enabling real-time parameter adjustment, meeting diverse application scenarios, and enhancing mission flexibility.

[0106] Based on any of the foregoing embodiments, the second determining unit 530 is specifically configured to: When the imaging mode is a spotlight mode or a stripe mode, determining a first number of pulses based on an imaging duration and a pulse repetition frequency of the target position, and using the first number of pulses as the imaging information; When the imaging mode is a scanning mode, the second number of pulses is determined based on the imaging duration of each sub-band and the pulse repetition frequency, and the number of beam scans is determined based on the imaging duration and the scanning mode sub-band cycle period, and the second number of pulses and the number of beam scans are used as the imaging information.

[0107] Based on any of the above embodiments, the device further includes an imaging parameter preset table acquisition unit, wherein the imaging parameter preset table acquisition unit specifically includes: an orbit altitude determining unit, configured to determine the orbit altitude relative to the sea level based on orbit prediction information; a target maximum value determining unit, configured to determine a target maximum value of an equivalent orbit altitude based on the maximum value of the orbit altitude relative to sea level; a range determining unit, configured to determine a target minimum value of the equivalent orbit altitude based on the minimum value of the orbit altitude relative to sea level and the maximum value of the digital elevation of the ground, and determine an equivalent orbit altitude range based on the target maximum value and the target minimum value; A determination subunit is configured to determine the preset imaging parameter table based on the equivalent orbit altitude range.

[0108] Based on any of the foregoing embodiments, the determining subunit is specifically configured to: Determine the available range of pulse repetition frequencies for different imaging modes based on known platform parameters, known radar parameters, and different orbital altitudes; Determining a duty cycle of the pulse signal based on a platform power consumption constraint, and determining a pulse width based on the duty cycle; Determine a zebra pattern based on radar transmission timing and sub-satellite point constraints, determine a beam position based on the zebra pattern and radar beam width, and determine a pulse repetition frequency based on the beam position and an original imaging mode; Based on the requirements of resolution, range ambiguity and azimuth ambiguity, noise equivalent backscatter coefficient and data rate, the available parameters of all beam positions are determined; the available parameters include the viewing angle at the near end of the beam position, the viewing angle at the far end of the beam position, the viewing angle at the beam center, the pulse repetition frequency in the available range, the pulse width, bandwidth, sampling rate, sub-band imaging time of the scanning mode, imaging time of the beamforming mode, original gain control parameters and the equivalent orbit altitude range; Based on the available parameters, the imaging parameter preset table is determined.

[0109] Based on any of the foregoing embodiments, the second determining unit 530 is specifically configured to: Determining the number of echo reception delay pulses based on the proximal slant range and the speed of light; The sampling start is determined based on the echo reception delay pulse number and the pulse repetition period.

[0110] Based on any of the foregoing embodiments, the second determining unit 530 is specifically configured to: The sampling duration is determined based on the far-end slant distance, the near-end slant distance, the pulse duration, and the sampling protection time interval.

[0111] Based on any of the above embodiments, the mission annotation information includes the position coordinates of the target point, the digital elevation value of the target point, the ground feature type of the target point, the resolution, the polarization mode and the expected imaging time.

[0112] Figure 6 An example of a physical structure diagram of an electronic device is shown below. Figure 6As shown, the electronic device may include: a processor 610, a communications interface 620, a memory 630 and a communications bus 640, wherein the processor 610, the communications interface 620 and the memory 630 communicate with each other via the communications bus 640. The processor 610 may call the logic instructions in the memory 630 to execute an on-orbit autonomous mission planning method for a satellite-borne synthetic aperture radar, the method comprising: obtaining imaging parameter information; the imaging parameter information is determined by a satellite imaging system based on mission annotation information, orbit information and an imaging parameter preset table, the mission annotation information being obtained by the satellite imaging system through analysis of the user's observation requirements; the orbit information is determined based on satellite forecast information, and the imaging parameter preset table is used to reflect the imaging parameters set by the satellite imaging system under different conditions; the imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, and polarization mode. , target type and imaging mode; determine the waveposition imaging parameters based on the orbit altitude, the downward viewing angle, the imaging mode and the preset imaging parameter table, and determine the gain control parameters based on the polarization mode and the target type; determine the proximal slant distance and the waveposition distal slant distance based on the waveposition downward viewing angle range in the waveposition imaging parameters, determine the sampling start based on the proximal slant distance, determine the sampling duration based on the proximal slant distance and the waveposition distal slant distance, and determine the imaging information corresponding to the imaging mode; perform spaceborne synthetic aperture radar imaging based on the waveposition imaging parameters, the gain control parameters, the sampling start, the sampling duration and the imaging information.

[0113] Furthermore, the logic instructions in the aforementioned memory 630 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, or the portion that contributes to the prior art, or a portion 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 for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0114] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the on-orbit autonomous mission planning method of the satellite-borne synthetic aperture radar provided by the above methods, and the method includes: obtaining imaging parameter information; the imaging parameter information is determined by the satellite imaging system based on mission annotation information, orbit information and imaging parameter preset table, and the mission annotation information is obtained by the satellite imaging system through analysis of the user's observation needs; the orbit information is determined based on satellite forecast information, and the imaging parameter preset table is used to reflect the imaging parameters set by the satellite imaging system under different conditions; the imaging The parameter information includes orbital altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type and imaging mode; based on the orbital altitude, the downward viewing angle, the imaging mode and the preset imaging parameter table, the wave position imaging parameters are determined, and based on the polarization mode and the target type, the gain control parameters are determined; based on the wave position downward viewing angle range in the wave position imaging parameters, the near-end slant range and the wave position far-end slant range are determined, the sampling start is determined based on the near-end slant range, the sampling duration is determined based on the near-end slant range and the wave position far-end slant range, and imaging information corresponding to the imaging mode is determined; and spaceborne synthetic aperture radar imaging is performed based on the wave position imaging parameters, the gain control parameters, the sampling start, the sampling duration and the imaging information.

[0115] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented by a processor to execute the on-orbit autonomous mission planning method for a satellite-borne synthetic aperture radar provided by the above methods, the method comprising: obtaining imaging parameter information; the imaging parameter information is determined by a satellite imaging system based on mission annotation information, orbit information and an imaging parameter preset table, the mission annotation information being obtained by the satellite imaging system through analysis of the user's observation needs; the orbit information is determined based on satellite forecast information, and the imaging parameter preset table is used to reflect the imaging parameters set by the satellite imaging system under different conditions; the imaging parameter information includes orbit altitude, the satellite The invention relates to a method for determining a downward viewing angle, a polarization mode, a target type and an imaging mode between a star imaging system and a target; determining a wave position imaging parameter based on the orbital altitude, the downward viewing angle, the imaging mode and the preset imaging parameter table, and determining a gain control parameter based on the polarization mode and the target type; determining a proximal slant distance and a distal slant distance of the wave position based on the wave position downward viewing angle range in the wave position imaging parameter, determining a sampling start based on the proximal slant distance, determining a sampling duration based on the proximal slant distance and the distal slant distance of the wave position, and determining imaging information corresponding to the imaging mode; and performing spaceborne synthetic aperture radar imaging based on the wave position imaging parameter, the gain control parameter, the sampling start, the sampling duration and the imaging information.

[0116] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0117] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion 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, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for autonomous on-orbit mission planning of a spaceborne synthetic aperture radar, characterized in that: include: Obtain imaging parameter information; The imaging parameter information is determined by the satellite imaging system based on mission annotation information, orbit information, and an imaging parameter preset table. The mission annotation information is obtained by the satellite imaging system by analyzing the user's observation requirements. The orbit information is determined based on satellite forecast information. The imaging parameter preset table is used to reflect the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode. Determining wave position imaging parameters based on the orbit altitude, the downward viewing angle, the imaging mode, and the preset imaging parameter table, and determining gain control parameters based on the polarization mode and the target type; Determining a proximal slant distance and a distal slant distance of the wave position based on the viewing angle range of the wave position in the wave position imaging parameters, determining a sampling start based on the proximal slant distance, determining a sampling duration based on the proximal slant distance and the distal slant distance of the wave position, and determining imaging information corresponding to the imaging mode; Spaceborne synthetic aperture radar imaging is performed based on the wave position imaging parameter, the gain control parameter, the sampling start, the sampling duration and the imaging information.

2. The method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar according to claim 1, characterized in that: The determining of imaging information corresponding to the imaging mode includes: When the imaging mode is a spotlight mode or a stripe mode, determining a first number of pulses based on an imaging duration and a pulse repetition frequency of the target position, and using the first number of pulses as the imaging information; When the imaging mode is a scanning mode, the second number of pulses is determined based on the imaging duration of each sub-band and the pulse repetition frequency, and the number of beam scans is determined based on the imaging duration and the scanning mode sub-band cycle period, and the second number of pulses and the number of beam scans are used as the imaging information.

3. The method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar according to claim 1, wherein: The step of obtaining the preset imaging parameter table includes: Determine the orbit altitude relative to sea level based on orbit prediction information; determining a target maximum value of an equivalent orbit altitude based on the maximum value of the orbit altitude relative to sea level; determining a target minimum value of the equivalent orbit altitude based on the minimum value of the orbit altitude relative to sea level and the maximum value of the digital elevation of the ground, and determining an equivalent orbit altitude range based on the target maximum value and the target minimum value; Based on the equivalent orbit altitude range, the imaging parameter preset table is determined.

4. The method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar according to claim 3, characterized in that: The step of determining the preset imaging parameter table based on the equivalent orbit altitude range includes: Determine the available range of pulse repetition frequencies for different imaging modes based on known platform parameters, known radar parameters, and different orbital altitudes; Determining a duty cycle of the pulse signal based on a platform power consumption constraint, and determining a pulse width based on the duty cycle; Determine a zebra pattern based on radar transmission timing and sub-satellite point constraints, determine a beam position based on the zebra pattern and radar beam width, and determine a pulse repetition frequency based on the beam position and an original imaging mode; Based on the requirements of resolution, range ambiguity and azimuth ambiguity, noise equivalent backscatter coefficient and data rate, the available parameters of all beam positions are determined; the available parameters include the viewing angle at the near end of the beam position, the viewing angle at the far end of the beam position, the viewing angle at the beam center, the pulse repetition frequency in the available range, the pulse width, bandwidth, sampling rate, sub-band imaging time of the scanning mode, imaging time of the beamforming mode, original gain control parameters and the equivalent orbit altitude range; Based on the available parameters, the imaging parameter preset table is determined.

5. The method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar according to any one of claims 1 to 4, characterized in that: The determining of the sampling start based on the proximal slant distance comprises: Determining the number of echo reception delay pulses based on the proximal slant range and the speed of light; The sampling start is determined based on the echo reception delay pulse number and the pulse repetition period.

6. The method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar according to any one of claims 1 to 4, characterized in that: The determining of the sampling duration based on the proximal slant distance and the distal slant distance of the wave position includes: The sampling duration is determined based on the far-end slant distance, the near-end slant distance, the pulse duration, and the sampling protection time interval.

7. The method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar according to any one of claims 1 to 4, characterized in that: The mission annotation information includes the position coordinates of the target point, the digital elevation value of the target point, the ground feature type of the target point, the resolution, the polarization mode and the expected imaging time.

8. An on-orbit autonomous mission planning device for a spaceborne synthetic aperture radar, characterized in that: include: an acquisition unit, configured to acquire imaging parameter information; The imaging parameter information is determined by the satellite imaging system based on mission annotation information, orbit information, and an imaging parameter preset table. The mission annotation information is obtained by the satellite imaging system by analyzing the user's observation requirements. The orbit information is determined based on satellite forecast information. The imaging parameter preset table is used to reflect the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbit altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode. a first determining unit, configured to determine a wave position imaging parameter based on the orbit altitude, the downward viewing angle, the imaging mode, and the preset imaging parameter table, and to determine a gain control parameter based on the polarization mode and the target type; a second determining unit, configured to determine a proximal slant distance and a distal slant distance of the waveposition based on the viewing angle range of the waveposition in the waveposition imaging parameters, determine a sampling start based on the proximal slant distance, determine a sampling duration based on the proximal slant distance and the distal slant distance of the waveposition, and determine imaging information corresponding to the imaging mode; An imaging unit is configured to perform spaceborne synthetic aperture radar imaging based on the wave position imaging parameter, the gain control parameter, the sampling start, the sampling duration, and the imaging information.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the on-orbit autonomous mission planning method for a spaceborne synthetic aperture radar is implemented as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar as claimed in any one of claims 1 to 7 is implemented.

Images