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

Abstract

The application relates to the field of aerospace microwave remote sensing technology and provides a kind of on-orbit autonomous task planning method, device and equipment of satellite-borne synthetic aperture radar, the method comprises: obtaining imaging parameter information;Imaging parameter information is determined by satellite imaging system based on task annotation information, orbit information and imaging parameter preset table, and the task annotation information is obtained by analyzing the observation demand of the user by the satellite imaging system;The orbit information is determined based on satellite prediction information. In the method, the imaging parameter information is determined by the satellite imaging system based on the task annotation information, the orbit information and the imaging parameter preset table, the traditional satellite-borne SAR task planning part parameter calculation and instruction generation process is moved to the satellite, the manual calculation and the ground annotation step are saved, and the dependence of the task planning process on the ground calculation is reduced;The task annotation information is obtained by analyzing the observation demand of the user by the satellite imaging system, the observation demand can be annotated in advance, satellite resources are fully utilized, and the task execution efficiency is greatly improved.

Description

Technical Field

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

[0002] Traditional spaceborne Synthetic Aperture Radar (SAR) mission planning methods have limited adaptability in satellite orbit adjustments or complex mission environments. Because traditional spaceborne SAR mission planning methods are complex and time-consuming, requiring a long lead time for parameter preparation, they are highly dependent on orbit prediction information from ground systems. However, when adjusting satellite orbits or facing complex and variable mission scenarios, the accuracy of orbit prediction information can be significantly reduced. Due to inaccurate orbit information, the calculated observation parameters (such as wavefront and imaging time) will deviate from actual requirements, directly affecting imaging quality and results.

[0003] Furthermore, this method is complex and consumes significant manpower and resources. Traditional methods require manual completion of multiple ground steps, including orbit prediction, parameter calculation, command generation, and ground-based data transfer. This cumbersome process is not only inefficient but also increases labor and time costs. Ground-based data transfer relies on satellite transit time, which carries the risk of failure and delayed observation. Ground-based data transfer can only be performed during satellite transit, but satellite transit time is limited and uncontrollable. If data transfer cannot be completed within the predetermined time, observation commands will not be transmitted to the satellite in a timely manner, causing the mission to be unable to be executed on schedule.

[0004] Traditional methods lack flexibility and struggle to adapt to dynamic mission requirements. They require advance mission planning and cannot be dynamically adjusted based on real-time track information or unforeseen mission needs. When facing complex and ever-changing mission scenarios such as emergency observation, their flexibility is clearly insufficient, failing to meet the urgent need for rapid response. If mission execution is hindered, the entire planning process must be restarted, exacerbating the difficulty and cost of planning and execution. Summary of the Invention

[0005] This invention provides a method, apparatus, and equipment for on-orbit autonomous mission planning of spaceborne synthetic aperture radar, which addresses the shortcomings of traditional spaceborne synthetic aperture radar mission planning methods in the prior art.

[0006] This invention provides an on-orbit autonomous mission planning method for spaceborne synthetic aperture radar, comprising the following steps:

[0007] The imaging parameter information is obtained 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 through analysis of the user's observation requirements. The orbit information is determined based on satellite forecast information. The imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions. 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.

[0008] Based on the orbital altitude, the downward viewing angle, the imaging mode, and the imaging parameter preset table, wavefront imaging parameters are determined, and based on the polarization mode and the target type, gain control parameters are determined.

[0009] Based on the wavefront imaging parameters, the near-end slant range and the 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 far-end slant range. The imaging information corresponding to the imaging mode is also determined.

[0010] Spaceborne synthetic aperture radar imaging is performed based on the wavefront imaging parameters, the gain control parameters, the sampling start, the sampling duration, and the imaging information.

[0011] According to the present invention, a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar includes determining the imaging information corresponding to the imaging mode, comprising:

[0012] When the imaging mode is a spotlight mode or a strip mode, the number of first pulses is determined based on the imaging duration and pulse repetition frequency of the target location, and the number of first pulses is used as the imaging information.

[0013] When the imaging mode is a scanning mode, the number of second 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 sub-band cycle period of the scanning mode. The number of second pulses and the number of beam scans are used as the imaging information.

[0014] According to the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the present invention, the step of obtaining the imaging parameter preset table includes:

[0015] Based on orbital prediction information, the orbital altitude relative to sea level is determined;

[0016] Based on the maximum value of the orbital altitude relative to sea level, determine the target maximum value of the equivalent orbital altitude;

[0017] Based on the minimum orbital altitude relative to sea level and the maximum digital elevation of the ground, a target minimum of the equivalent orbital altitude is determined, and based on the target maximum and the target minimum, a range of equivalent orbital altitudes is determined.

[0018] Based on the equivalent orbital altitude range, the imaging parameter preset table is determined.

[0019] According to the present invention, a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar includes determining the imaging parameter preset table based on the equivalent orbital altitude range, comprising:

[0020] Based on known platform parameters, known radar parameters, and different orbital altitudes, the usable range of pulse repetition frequencies for different imaging modes is determined;

[0021] Based on platform power consumption constraints, the duty cycle of the pulse signal is determined, and based on the duty cycle, the pulse width is determined.

[0022] Based on the constraints of radar transmission timing and nadir point, the zebra pattern is determined, and based on the zebra pattern and radar beam width, the wave position is determined, and based on the wave position and original imaging mode, the pulse repetition frequency is determined.

[0023] Based on resolution, range ambiguity and azimuth ambiguity, noise equivalent backscattering coefficient and data rate requirements, the available parameters for all wave positions are determined. The available parameters include the near-end lower angle of view of the wave position, the far-end lower angle of view of the wave position, the beam center lower angle of view, the pulse repetition frequency in the available range, the pulse width, bandwidth, sampling rate, sub-band imaging duration of the scanning mode, imaging duration of the spotlight mode, the original gain control parameters, and the equivalent orbital altitude range.

[0024] Based on the available parameters, the imaging parameter preset table is determined.

[0025] According to the present invention, a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar includes determining the sampling start based on the near-end slant range, comprising:

[0026] Based on the near-end slant range and the speed of light, the number of echo reception delay pulses is determined;

[0027] The sampling start is determined based on the number of echo reception delay pulses and the pulse repetition period.

[0028] According to the present invention, a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar includes determining the sampling duration based on the near-end slant range and the far-end slant range, comprising:

[0029] The sampling duration is determined based on the far-end slant distance, the near-end slant distance, the pulse width, and the sampling protection time interval.

[0030] According to the present invention, a method for on-orbit autonomous mission planning of a spaceborne synthetic aperture radar is provided, wherein the mission information includes the position coordinates of the target's location point, the digital elevation value of the target point, the ground feature type, resolution, polarization mode, and desired imaging time of the target point.

[0031] The present invention also provides an on-orbit autonomous mission planning device for spaceborne synthetic aperture radar, comprising the following units:

[0032] An acquisition unit is used to acquire imaging parameter information. This imaging parameter information is determined by the satellite imaging system based on mission annotation information, orbital information, and an imaging parameter preset table. The mission annotation information is obtained by the satellite imaging system through analysis of the user's observation requirements. The orbital information is determined based on satellite forecast information. The imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbital altitude, the downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode.

[0033] The first determining unit is used to determine wavefront imaging parameters based on the orbital height, the downward viewing angle, the imaging mode, and the imaging parameter preset table, and to determine gain control parameters based on the polarization mode and the target type.

[0034] The second determining unit is used to determine the near-end slant range and the far-end slant range based on the slant range of the slant view in the slant imaging parameters, determine the sampling start based on the near-end slant range, determine the sampling duration based on the near-end slant range and the far-end slant range, and determine the imaging information corresponding to the imaging mode.

[0035] An imaging unit is used to perform spaceborne synthetic aperture radar imaging based on the wavefront imaging parameters, the gain control parameters, the sampling start, the sampling duration, and the imaging information.

[0036] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar as described above.

[0037] 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 on-orbit autonomous mission planning method for spaceborne synthetic aperture radar as described above.

[0038] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar as described above.

[0039] The present invention provides a method, apparatus, and equipment for on-orbit autonomous mission planning of spaceborne synthetic aperture radar, which acquires 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 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 orbital 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 parameters are determined by the satellite imaging system based on mission-injected information, orbital information, and preset imaging parameter tables. This moves the parameter calculation and command generation processes of traditional spaceborne SAR mission planning to the satellite, reducing the reliance on ground calculations in the mission planning process and reducing the consumption of manpower and resources. On the other hand, the mission-injected information is obtained by the satellite imaging system through analysis of the user's observation needs. This eliminates manual calculations and ground-based injection steps, allowing for advance injection of observation needs, full utilization of satellite resources, significantly improving mission execution efficiency, and enabling rapid response to dynamic observation needs. It also enables real-time parameter adjustments to meet diverse application scenarios and enhance mission flexibility. Attached Figure Description

[0040] 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.

[0041] Figure 1 This is one of the flowcharts illustrating the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by this invention.

[0042] Figure 2 This is a schematic diagram of the space geometry between the Earth and space provided by the present invention.

[0043] Figure 3 This is a flowchart illustrating step 240 in the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the present invention.

[0044] Figure 4 This is the second flowchart illustrating the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by this invention.

[0045] Figure 5 This is a schematic diagram of the on-orbit autonomous mission planning device for spaceborne synthetic aperture radar provided by the present invention.

[0046] Figure 6 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0047] 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.

[0048] The terms "first," "second," etc., used in this invention are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and that the objects distinguished by "first," "second," etc., are generally of the same class.

[0049] In existing technologies, spaceborne synthetic aperture radar is an imaging radar that uses the relative motion between itself and the target to achieve high-resolution observation. It has high-resolution, wide-swath, all-day, all-weather, and global imaging capabilities, and has broad application prospects in fields such as military reconnaissance, disaster monitoring, resource surveys, and marine research.

[0050] In spaceborne SAR imaging, SAR imaging mission planning plays a crucial role. It serves as a bridge connecting the satellite platform, payload performance, and practical application requirements, directly impacting whether the SAR system can efficiently and accurately complete various observation tasks. Mission planning not only determines the satellite's observation strategy, imaging mode, and control, but also profoundly affects the timeliness, resolution, and coverage of the observation data, thereby further influencing the effectiveness of subsequent data analysis and applications.

[0051] Traditional spaceborne SAR mission planning methods involve complex operational procedures, requiring manual completion of orbit prediction, parameter calculation, and command generation, which consumes significant manpower and resources. These methods rely on ground systems for advance orbit prediction, which can be inaccurate, especially in orbit adjustment or complex mission scenarios, leading to deviations in observation parameter calculations and impacting imaging quality. Furthermore, ground-based data transmission depends on satellite transit time, posing a risk of delayed transmission and potentially causing mission failure. Additionally, traditional methods lack flexibility and struggle to adapt to dynamic mission requirements, particularly in emergency observation scenarios. The high risk associated with traditional methods negatively impacts overall efficiency.

[0052] With the increasing computing and storage capabilities of satellites and the growing demand from users for flexibility, accuracy, and ease of operation in spaceborne synthetic aperture radar (SAR) mission planning.

[0053] To address the aforementioned problems, this invention provides an on-orbit autonomous mission planning method for spaceborne synthetic aperture radar. Figure 1 This is one of the flowcharts illustrating the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by this invention, such as... Figure 1 As shown, the method includes the following:

[0054] Step 110: Obtain 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. 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. 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 orbital altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode.

[0055] Specifically, imaging parameter information can be obtained. This information is determined by the satellite imaging system based on mission annotation information, orbital information, and a preset imaging parameter table. Here, mission annotation information is obtained by the satellite imaging system through analysis of the user's observation requirements. In other words, mission annotation information refers to a series of instructions and parameters generated by the satellite imaging system after analysis and processing based on the user's observation requirements. These instructions and parameters are used to guide the satellite's on-orbit operation and the execution of imaging tasks.

[0056] Here, the obtained observation requirements information is analyzed to form a mission requirements information package. Then, combined with orbital prediction information and ground station locations, the mission requirements information package is uploaded to the satellite at an appropriate time. The upload time for this step can be flexibly adjusted, allowing the mission requirements to be uploaded well in advance to ensure mission execution.

[0057] Here, the information on the task includes the location coordinates of the target point, the digital elevation value of the target point, the land feature type of the target point, the resolution, the polarization mode, the expected imaging time, and the imaging duration, etc. This embodiment of the invention does not specifically limit these.

[0058] The location coordinates of the target point may include the longitude, latitude and altitude of the target point, or the 84 coordinate system coordinates of the target point to be observed, etc. This embodiment of the invention does not make specific limitations on this.

[0059] The target point digital elevation value refers to the value of the target point in the Digital Elevation Model (DEM). The target point land feature type refers to the type of ground object at the target point, which can include grassland, forest, desert, bare soil, ocean, city, etc., but this embodiment of the invention does not specifically limit this.

[0060] Here, the resolution in the mission annotation information can be replaced with 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. This embodiment of the invention does not specifically limit this.

[0061] Here, the desired imaging time refers to the specific point in time when the user expects the satellite imaging system to perform imaging.

[0062] 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 neither of them is included in the mission information, imaging will be performed according to the appropriate time and default imaging duration planned autonomously by the satellite.

[0063] Orbit information is determined based on satellite forecast information, which is crucial data for satellite operation and management. It provides precise position and velocity information for a satellite at a future point in time or over a given period. Orbit information reflects the satellite's position and motion at a specific time.

[0064] 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 predetermined and stored in the satellite's storage unit for retrieval during on-orbit mission planning. This process can be completed before satellite launch, or it can be modified by ground-based annotation of wavelet information on the on-orbit satellite using the satellite's information uploading and mapping function.

[0065] The imaging parameters include orbital altitude, downward angle between the satellite imaging system and the target, polarization, target type, and imaging mode.

[0066] Here, orbital altitude refers to the vertical distance between the satellite's orbital plane and the Earth's surface when the satellite is in its orbit. Polarization refers to the polarization of electromagnetic waves in radar imaging. Polarization can include horizontal polarization, vertical polarization, and cross polarization, etc., but this embodiment of the invention does not specifically limit this.

[0067] The target type refers to the object that needs to be observed and identified during satellite imaging. The target type can be mountains, rivers, forests, farmland, etc., but this embodiment of the invention does not specifically limit it.

[0068] Imaging mode refers to the specific operating mode adopted by a satellite imaging system when acquiring images. Imaging modes may include strip mode, scan mode, spotlight mode, etc., and the embodiments of the present invention do not specifically limit them.

[0069] It should be noted that the imaging parameter information is determined by selecting imaging parameters that match the mission annotation information and orbital information from the imaging parameter preset table.

[0070] Understandably, pre-registering observation requirements avoids mission failure due to untimely registration, significantly reducing mission execution risks. Furthermore, on-orbit autonomous 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, particularly during satellite orbit adjustment.

[0071] Here, the parameters that need to be calculated on-orbit include: the target point downward viewing angle, left / right side viewing angle, satellite flight attitude (forward / backward flight), the equivalent orbital altitude at the imaging center time, the imaging time in seconds, the imaging duration, the millisecond time (the first imaging indicates the precise imaging time in ms; subsequent imaging indicates the relative time of the imaging start time with respect to the first imaging in 10ms), the mission serial number, and the imaging control word (primary / backup selection and number of imaging attempts), etc.

[0072] Figure 2 This is a schematic diagram of the space-to-ground geometry provided by the present invention. Indicates the near-end slope distance of the wave position. Indicates the slant distance at the far end of the wave position. Indicates the near-end downward angle of the wave position. Indicates the downward angle at the far end of the wave position. The far-end incident angle is represented by H, the equivalent orbital altitude is represented by H, and the Earth's radius at the target point is represented by Re. For example... Figure 2 As shown, the target's downward view and left and right side views are calculated by the satellite platform based on the satellite's position and the target's position, through the satellite-ground geometry and the satellite's flight direction; the forward and backward flight indicators are given by the satellite platform based on the current operating attitude.

[0073] The method for calculating the equivalent orbital altitude at the imaging center time is as follows: Given the satellite position (WGS84 coordinates) at the imaging center time, let it be: The target point DEM is The Earth's radius at the target point is Then the distance from the satellite to the Earth's center is The equivalent orbital altitude is .

[0074] The imaging time in seconds refers to the total number of seconds from 00:00:00 UTC on January 1, 2020, to the moment radar imaging begins, expressed as an integer. For strip and scan modes, the imaging time in seconds corresponds to the start time of imaging; for spotlight mode, the imaging time in seconds is the overpass time minus 10 seconds.

[0075] Step 120: Based on the orbital altitude, the downward viewing angle, the imaging mode, and the imaging parameter preset table, determine the wavefront imaging parameters, and based on the polarization mode and the target type, determine the gain control parameters.

[0076] Specifically, after obtaining the imaging parameter information, the wavefront imaging parameters can be determined based on the orbital altitude, downward viewing angle, imaging mode, and imaging parameter preset table within the imaging parameter information. More specifically, based on the matching result between the imaging mode and 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 wavefront in the target parameter table can be further located. Finally, the required imaging parameters are extracted from the corresponding wavefront, thus obtaining the wavefront imaging parameters. The wavefront 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. They determine how the radar beam illuminates the target area, the imaging signal parameters, and how the echo signal is received.

[0077] 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.

[0078] Step 130: Based on the wavefront under-view range in the wavefront imaging parameters, determine the near-end slant range and the far-end slant range, determine the sampling start based on the near-end slant range, determine the sampling duration based on the near-end slant range and the far-end slant range, and determine the imaging information corresponding to the imaging mode.

[0079] Specifically, based on the slant angle range in the slant-position imaging parameters, the near-end slant range and the far-end slant range are determined. Further, 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 the far-end slant range. The sampling start refers to the time point at which the radar system begins receiving echo signals from the target area. The sampling duration refers to the duration for which the radar system receives echo signals from the target area.

[0080] Near-end slant range refers to the straight-line distance between the radar antenna and the nearest point in the target's bandgap region. Far-end slant range refers to the straight-line distance between the radar antenna and the farthest point in the target's bandgap region.

[0081] Then, the imaging information corresponding to the imaging mode is determined. Here, different imaging modes correspond to different imaging information.

[0082] Step 140: Perform spaceborne synthetic aperture radar imaging based on the wavefront imaging parameters, the gain control parameters, the sampling start, the sampling duration, and the imaging information.

[0083] Specifically, after obtaining the gain control parameters, based on the wavefront imaging parameters, the transmitted pulse signal parameters (bandwidth, pulse width, and pulse repetition frequency) and received signal sampling rate of the SAR payload can be configured; according to the sampling parameter calculation results (including the sampling start time and sampling duration), the sampling window parameters for the mission reception phase are set; combined with the gain control parameters, the receive gain control mode and initial gain value are determined; based on the left and right side-look analysis results, the satellite side-swing direction is planned, and based on the wavefront center down-view angle and azimuth scanning angle, the two-dimensional scanning strategy of the SAR payload antenna is designed; in addition, according to the polarization mode and imaging mode (such as strip mode, spotting mode, scanning mode, etc.) in the imaging parameters, the working mode of the SAR payload (including the on / off state of the transmit and receive polarization channels, the specific SAR working mode, and data marking rules) is determined. Finally, by combining the above parameter configurations and imaging mission requirements, the spaceborne synthetic aperture radar mission is completed. Among them, the polarization modes include HH (Horizontal-Horizontal), HV (Horizontal-Vertical), VH (Vertical-Horizontal), and VV (Vertical-Vertical), etc., which are not specifically limited in this embodiment of the invention.

[0084] The method provided in this invention acquires 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 through analysis of the user's observation requirements. The orbit information is determined based on satellite forecast information. The imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions. 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. Subsequent spaceborne synthetic aperture radar imaging is then performed based on the imaging parameter information. On the one hand, the imaging parameters are determined by the satellite imaging system based on mission-injected information, orbital information, and preset imaging parameter tables. This moves the parameter calculation and command generation process of traditional spaceborne SAR mission planning to the satellite, reducing the reliance on ground calculations in the mission planning process, reducing manpower and material consumption, and eliminating manual calculations and ground-based injection steps. On the other hand, the mission-injected information is obtained by the satellite imaging system through analysis of the user's observation needs. By injecting observation needs in advance, satellite resources are fully utilized, mission execution efficiency is greatly improved, and dynamic observation needs can be responded to quickly, enabling real-time parameter adjustments to meet diverse application scenarios and enhance mission flexibility.

[0085] Based on the above embodiments, step 130, determining the imaging information corresponding to the imaging mode, includes:

[0086] Step 131: When the imaging mode is a spotlight mode or a strip mode, determine the number of first pulses based on the imaging duration and pulse repetition frequency of the target location, and use the number of first pulses as the imaging information.

[0087] Step 132: When the imaging mode is a scanning mode, determine the number of second 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 sub-band cycle period of the scanning mode, and use the number of second pulses and the number of beam scans as the imaging information.

[0088] Specifically, when the imaging mode is spotlight mode or strip mode, the number of first pulses is determined based on the imaging duration and pulse repetition frequency of the target location, and the number of first pulses is used as imaging information.

[0089] Here, the formula for the number of the first pulses is as follows:

[0090]

[0091] in, Indicates the number of the first pulse. Indicates the pulse repetition frequency. The imaging duration indicates the location of the target.

[0092] When the imaging mode is scanning mode, the number of second 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 sub-band cycle period of the scanning mode. The number of second pulses and the number of beam scans are used as imaging information.

[0093] Here, the formula for the number of second pulses is as follows:

[0094]

[0095] in, Indicates the number of the second pulse. Indicates the pulse repetition frequency. This indicates the imaging duration of each subband.

[0096] Here, based on the imaging duration and the sub-band cycle period of the scanning mode, the formula for determining the number of beam scans (Burst cycles) is as follows:

[0097]

[0098] in, Indicates the number of beam scans. The imaging duration indicates the location of the target. This indicates the sub-band cycle period of the scan mode.

[0099] It should be noted that the imaging time for the scanning mode should be [missing information]. Integer multiples of.

[0100] Based on the above embodiments, the step of obtaining the imaging parameter preset table includes:

[0101] Step 210: Determine the orbital altitude relative to sea level based on the orbital prediction information;

[0102] Step 220: Based on the maximum value of the orbital altitude relative to sea level, determine the target maximum value of the equivalent orbital altitude;

[0103] Step 230: Based on the minimum orbital height relative to sea level and the maximum digital elevation of the ground, determine the target minimum of the equivalent orbital height, and based on the target maximum and the target minimum, determine the range of the equivalent orbital height;

[0104] Step 240: Determine the imaging parameter preset table based on the equivalent orbital height range.

[0105] Specifically, based on orbital prediction information, the orbital altitude relative to sea level is determined. The orbital altitude relative to sea level can be determined using... express.

[0106] Based on orbital prediction information, the orbital altitude of a satellite relative to sea level at a specific time can be determined. This requires transforming the satellite's position from a geocentric-fixed coordinate system to a geocentric-horizontal coordinate system, then calculating the distance between the satellite and the Earth's center, and finally subtracting the Earth's radius to obtain the orbital altitude relative to sea level.

[0107] Then, it can be based on the maximum value of the orbital height relative to sea level ( ), determine the target maximum value of the equivalent orbital altitude.

[0108] Furthermore, the target minimum of the equivalent orbital altitude can be determined based on the minimum orbital altitude relative to sea level and the maximum digital elevation model (DEM) of the ground. Here, the target minimum of the equivalent orbital altitude is the minimum orbital altitude relative to sea level minus the maximum value of the DEM.

[0109] Finally, based on the maximum and minimum target values, the equivalent orbital altitude range is determined, and based on the equivalent orbital altitude range, the imaging parameter preset table is determined.

[0110] Based on the above embodiments, Figure 3 This is a flowchart illustrating step 240 of the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the present invention, as shown below. Figure 3 As shown, step 240 includes:

[0111] Step 241: Based on known platform parameters, known radar parameters, and different orbital altitudes, determine the available range of pulse repetition frequencies for different imaging modes;

[0112] Step 242: Based on the platform power consumption constraint, determine the duty cycle of the pulse signal, and based on the duty cycle, determine the pulse width;

[0113] Step 243: Based on the constraints of radar transmission timing and nadir point, determine the zebra pattern, and based on the zebra pattern and radar beam width, determine the wave position, and based on the wave position and original imaging mode, determine the pulse repetition frequency.

[0114] Step 244: Based on resolution, range ambiguity and azimuth ambiguity, noise equivalent backscattering coefficient and data rate requirements, determine the available parameters for all wave positions; the available parameters include the near-end lower angle of view of the wave position, the far-end lower angle of view of the wave position, the beam center lower angle of view, the pulse repetition frequency in the available range, the pulse width, bandwidth, sampling rate, sub-band imaging duration of the scanning mode, imaging duration of the spotlight mode, the original gain control parameters, and the equivalent orbital height range.

[0115] Step 245: Based on the available parameters, determine the imaging parameter preset table.

[0116] Specifically, based on known platform parameters, known radar parameters, and different orbital altitudes, the usable range of pulse repetition frequencies for different imaging modes is determined. Here, known platform parameters include the satellite platform's speed, altitude, etc., and known radar parameters include the radar's operating frequency, wavelength, antenna length, etc., which are not specifically limited in this embodiment of the invention.

[0117] Then, based on platform power consumption constraints, the duty cycle of the pulse signal is determined, and based on the duty cycle, the pulse width is determined. That is, under platform power consumption constraints, the duty cycle D of the pulse signal is determined; the duty cycle is the pulse width. T on and the entire cycle time T The ratio, where, T=T on+ T off , T off It is the pulse interval time.

[0118] The pulse width is obtained by multiplying the duty cycle by the total cycle time.

[0119] Furthermore, the zebra pattern can be determined based on the radar transmission timing and the constraints of the nadir point.

[0120] The radar transmission timing is determined based on the radar's pulse width, pulse repetition period, and the leading and trailing edge times of the target echo. To ensure complete echo reception, the leading edge time of the target echo signal must be greater than the trailing edge time of the previous transmitted pulse, and the trailing edge time of the echo signal must be less than the leading edge time of the next pulse. The nadir point constraints are determined based on satellite orbit parameters, pulse repetition frequency, nadir point echo width, and the leading and trailing edge times of the target echo signal. To avoid the influence of the nadir point echo, the leading edge time of the target echo signal must be greater than the trailing edge time of the previous nadir point echo, and the trailing edge time of the target echo signal must be less than the leading edge time of the next nadir point echo. Combining the radar transmission timing constraints with the nadir point constraints generates a zebra diagram. The zebra diagram is a two-dimensional chart where the horizontal axis represents the pulse repetition frequency value, and the vertical axis represents the downward viewing angle range. Different colors or lines represent the timing diagram of the radar pulse transmission cutoff zone and the nadir point echo window.

[0121] Then, based on the radar observation swath width and the overlap swath width between wave positions, the wave position division is determined. Wave position refers to the projection position of the radar beam on the ground.

[0122] Furthermore, based on the predefined wave positions and zebra diagram constraints, the pulse repetition frequency that satisfies the transmission and reception timing requirements and the sub-satellite point timing requirements is determined.

[0123] Finally, based on resolution, range ambiguity and azimuth ambiguity, noise equivalent backscattering coefficient and data rate requirements, the available parameters for all wave positions are determined. These available parameters include the near-end downward angle of the wave position, the far-end downward angle of the wave position, the beam center downward angle, the pulse repetition frequency, the pulse width, the bandwidth, the sampling rate, the sub-band imaging duration of the scanning mode, the imaging duration of the spotting mode, the original gain control parameters, and the equivalent orbital altitude range.

[0124] Here, range ambiguity refers to the limitation of radar pulse repetition frequency, causing echo signals from other regions with delays differing from the imaging band echo signals by integer numbers of pulse repetition periods to enter the receiver through antenna sidelobes, resulting in overlap in the range direction and making it impossible to correctly distinguish targets. Azimuth ambiguity refers to the Doppler signals with frequencies higher than the pulse repetition frequency being folded into the processing bandwidth of the central part of the azimuth spectrum after sampling, resulting in aliasing in the azimuth spectrum and making it impossible to correctly distinguish targets.

[0125] The noise equivalent backscattering coefficient is a key parameter in synthetic aperture radar systems for measuring radiometric resolution or system sensitivity. It represents the minimum backscattering intensity that can be reliably detected in a radar image ( The backscattering coefficient is the value when the target echo power equals the system noise power. The lower the value, the stronger the radar system's ability to detect weakly scattering targets (higher sensitivity).

[0126] Data rate requirement refers to the amount of data that a radar system needs to process, and is typically determined by factors such as imaging mode, bandwidth, and sampling rate. The data rate requirement determines the radar system's ability to process and transmit data.

[0127] It should be noted that all available parameters for all wave positions must meet the requirements for resolution, range ambiguity and azimuth ambiguity, noise equivalent backscattering coefficient and data rate.

[0128] Finally, based on the available parameters, a preset table of imaging parameters is determined. In this embodiment of the invention, in order to obtain a wavefront information table covering all orbital heights, it is necessary to divide the equivalent orbital heights, and then iterate the above process according to different orbital heights to generate multiple sets of wavefront information tables.

[0129] Based on the above embodiments, the step 130 of determining the sampling start based on the near-end slope distance includes:

[0130] Step 130-1: Based on the near-end slant range and the speed of light, determine the number of echo reception delay pulses;

[0131] Step 130-2: Determine the sampling start based on the number of echo reception delay pulses and the pulse repetition period.

[0132] 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:

[0133]

[0134] in, Indicates the number of echo reception delay pulses. Indicates the proximal slope distance. Represents the speed of light. Indicates to Round down. This indicates the pulse repetition period.

[0135] Then, based on the number of echo reception delay pulses and the pulse repetition period, the sampling start is determined, as follows:

[0136]

[0137] in, Indicates the start of sampling. Indicates the number of echo reception delay pulses. Indicates the proximal slope distance. Represents the speed of light. This indicates the pulse repetition period.

[0138] Based on the above embodiments, step 130, which involves determining the sampling duration based on the near-end slant range and the far-end slant range, includes:

[0139] The sampling duration is determined based on the far-end slant distance, the near-end slant distance, the pulse width, and the sampling protection time interval.

[0140] Specifically, the sampling duration is determined based on the far-end slant distance, near-end slant distance, pulse width, and sampling protection time interval, using the following formula:

[0141]

[0142] in, Indicates the sampling duration. Indicates the slant distance at the far end of the wave position. Indicates the proximal slope distance. Indicates the pulse width. Indicates the sampling protection time interval. It represents the speed of light.

[0143] It should be noted that, The sampling duration is one frame.

[0144] Based on any of the above embodiments Figure 4 This is the second flowchart illustrating the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by this invention. Figure 4As shown, the method includes the following steps:

[0145] Step 1, Establishing the Imaging Parameter Preset Table: Considering the changes in Earth's radius, orbital altitude, and target point digital elevation model values, calculate the imaging parameter tables for different modes and altitudes based on imaging parameter constraints.

[0146] Step 2, Imaging Parameter Presetting: The calculated imaging parameter information table is preset into the satellite storage unit. This step can support on-orbit updates of the satellite.

[0147] Step 3: Clarify user observation requirements: Based on the observation requirements, determine the location coordinates of the target point, the DEM of the target point, the type of ground features at the target point, the resolution, the polarization mode, and the expected imaging time, etc.

[0148] Step 4, Mission Requirements Upload: Package the information specified in Step 3 onto the ground and upload it to the satellite using a ground station.

[0149] Step 5, Satellite parameter calculation and transmission: Based on the mission annotation information and orbital information, the satellite calculates the equivalent orbital altitude of the target, the downward angle of the target point, and the satellite position at the time of satellite overhead. Then the satellite transmits the calculated data to the SAR payload.

[0150] Step 6, SAR payload parameter calculation and imaging: Based on the information received in step 5, the payload obtains the wavefront parameters and MGC values ​​by looking up a table, and obtains parameters such as the sampling start time and the start time of the spotlight mode imaging by calculation. Then, imaging is performed based on the parameters obtained by looking up the table and the calculated parameters.

[0151] The method provided in this invention moves some parameter calculations and command generation processes for traditional spaceborne SAR mission planning to the satellite, reducing the reliance on ground-based calculations for mission planning. Furthermore, this invention provides a method for implementing autonomous on-orbit mission planning for spaceborne SAR, enabling on-orbit implementation of spaceborne SAR mission planning based on existing SAR satellite system designs.

[0152] The following describes the on-orbit autonomous mission planning device for spaceborne synthetic aperture radar provided by the present invention. The on-orbit autonomous mission planning device for spaceborne synthetic aperture radar described below and the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar described above can be referred to in correspondence with each other.

[0153] Based on any of the above embodiments, the present invention provides an on-orbit autonomous mission planning device for spaceborne synthetic aperture radar. Figure 5 This is a schematic diagram of the on-orbit autonomous mission planning device for spaceborne synthetic aperture radar provided by the present invention, as shown below. Figure 5 As shown, the device includes:

[0154] The acquisition unit 510 is used 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 from analyzing the user's observation needs; 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 orbital altitude, downward viewing angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode.

[0155] The first determining unit 520 is used to determine wavefront imaging parameters based on the orbital height, the downward viewing angle, the imaging mode, and the imaging parameter preset table, and to determine gain control parameters based on the polarization mode and the target type.

[0156] The second determining unit 530 is used to determine the near-end slant range and the far-end slant range based on the slant range of the slant view in the slant imaging parameters, determine the sampling start based on the near-end slant range, determine the sampling duration based on the near-end slant range and the far-end slant range, and determine the imaging information corresponding to the imaging mode.

[0157] The imaging unit 540 is used to perform spaceborne synthetic aperture radar imaging based on the wavefront imaging parameters, the gain control parameters, the sampling start, the sampling duration, and the imaging information.

[0158] The apparatus provided in this invention acquires imaging parameter information. This imaging parameter information is determined by a satellite imaging system based on mission-injected information, orbital information, and an imaging parameter preset table. The mission-injected information is obtained by the satellite imaging system through analysis of the user's observation requirements. The orbital information is determined based on satellite forecast information. The imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions. 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. Subsequent spaceborne synthetic aperture radar imaging is then performed based on this imaging parameter information. On one hand, the imaging parameter information is determined by the satellite imaging system based on mission-injected information, orbital information, and the imaging parameter preset table. This moves the parameter calculation and command generation process of traditional spaceborne SAR mission planning to the satellite, reducing the reliance on ground calculations in the mission planning process, eliminating manual calculations and ground-based injection steps, and reducing manpower and material consumption. On the other hand, the mission-injected information is obtained by the satellite imaging system through analysis of the user's observation requirements. In advance, observation requirements are injected, fully utilizing satellite resources, significantly improving mission execution efficiency, and enabling rapid response to dynamic observation requirements. Real-time parameter adjustments are achieved to meet diverse application scenarios and enhance mission flexibility.

[0159] Based on any of the above embodiments, the second determining unit 530 is specifically used for:

[0160] When the imaging mode is a spotlight mode or a strip mode, the number of first pulses is determined based on the imaging duration and pulse repetition frequency of the target location, and the number of first pulses is used as the imaging information.

[0161] When the imaging mode is a scanning mode, the number of second 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 sub-band cycle period of the scanning mode. The number of second pulses and the number of beam scans are used as the imaging information.

[0162] Based on any of the above embodiments, an imaging parameter preset table acquisition unit is further included, wherein the imaging parameter preset table acquisition unit specifically includes:

[0163] Determine the orbital altitude unit, which is used to determine the orbital altitude relative to sea level based on orbital prediction information;

[0164] The target maximum value unit is used to determine the target maximum value of the equivalent orbital height based on the maximum value of the orbital height relative to sea level;

[0165] A range determination unit is used to determine a target minimum value of the equivalent orbital height based on the minimum value of the orbital height relative to sea level and the maximum value of the digital elevation of the ground, and to determine a range of the equivalent orbital height based on the target maximum value and the target minimum value.

[0166] A sub-unit is determined for using the equivalent orbital height range to determine the imaging parameter preset table.

[0167] Based on any of the above embodiments, the determining subunit is specifically used for:

[0168] Based on known platform parameters, known radar parameters, and different orbital altitudes, the usable range of pulse repetition frequencies for different imaging modes is determined;

[0169] Based on platform power consumption constraints, the duty cycle of the pulse signal is determined, and based on the duty cycle, the pulse width is determined.

[0170] Based on the constraints of radar transmission timing and nadir point, the zebra pattern is determined, and based on the zebra pattern and radar beam width, the wave position is determined, and based on the wave position and original imaging mode, the pulse repetition frequency is determined.

[0171] Based on resolution, range ambiguity and azimuth ambiguity, noise equivalent backscattering coefficient and data rate requirements, the available parameters for all wave positions are determined. The available parameters include the near-end lower angle of view of the wave position, the far-end lower angle of view of the wave position, the beam center lower angle of view, the pulse repetition frequency in the available range, the pulse width, bandwidth, sampling rate, sub-band imaging duration of the scanning mode, imaging duration of the spotlight mode, the original gain control parameters, and the equivalent orbital height range.

[0172] Based on the available parameters, the imaging parameter preset table is determined.

[0173] Based on any of the above embodiments, the second determining unit 530 is specifically used for:

[0174] Based on the near-end slant range and the speed of light, the number of echo reception delay pulses is determined;

[0175] The sampling start is determined based on the number of echo reception delay pulses and the pulse repetition period.

[0176] Based on any of the above embodiments, the second determining unit 530 is specifically used for:

[0177] The sampling duration is determined based on the far-end slant distance, the near-end slant distance, the pulse width, and the sampling protection time interval.

[0178] Based on any of the above embodiments, the task annotation information includes the location coordinates of the target's location point, the digital elevation value of the target point, the land feature type, resolution, polarization mode, and expected imaging time of the target point.

[0179] Figure 6 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 6As shown, the electronic device may include a processor 610, a communications interface 620, a memory 630, and a communication bus 640. The processor 610, communications interface 620, and memory 630 communicate with each other via the communication bus 640. The processor 610 can call logical instructions in the memory 630 to execute an on-orbit autonomous mission planning method for a spaceborne synthetic aperture radar. This method includes: 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. 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. The imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbital altitude, the downward angle between the satellite imaging system and the target, and polarization mode. The system determines the target type and imaging mode; based on the orbital altitude, the downward viewing angle, the imaging mode, and the imaging parameter preset table, it determines the wavefront imaging parameters and the gain control parameters based on the polarization mode and the target type; based on the wavefront downward viewing angle range in the wavefront imaging parameters, it determines the near-end slant range and the far-end slant range, determines the sampling start based on the near-end slant range, determines the sampling duration based on the near-end slant range and the far-end slant range, and determines the imaging information corresponding to the imaging mode; and performs spaceborne synthetic aperture radar imaging based on the wavefront imaging parameters, the gain control parameters, the sampling start, the sampling duration, and the imaging information.

[0180] Furthermore, the logical 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, in essence, 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.

[0181] 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 can execute the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the above methods. This method includes: acquiring 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 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 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, downward viewing angle, imaging mode, and imaging parameter preset table, wavefront imaging parameters are determined, and based on the polarization mode and target type, gain control parameters are determined. Based on the wavefront downward viewing angle range in the wavefront imaging parameters, near-end slant range and 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 far-end slant range, and imaging information corresponding to the imaging mode is determined. Based on the wavefront imaging parameters, the gain control parameters, the sampling start, the sampling duration, and the imaging information, spaceborne synthetic aperture radar imaging is performed.

[0182] 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, implements the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar provided by the methods described above. This method includes: acquiring 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; the imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions; the imaging parameter information includes orbital altitude, the satellite... The system determines the downward viewing angle, polarization, target type, and imaging mode between the star imaging system and the target; based on the orbital altitude, downward viewing angle, imaging mode, and imaging parameter preset table, it determines the wavefront imaging parameters and the gain control parameters based on the polarization and target type; based on the wavefront downward viewing angle range in the wavefront imaging parameters, it determines the near-end slant range and the far-end slant range, determines the sampling start based on the near-end slant range, determines the sampling duration based on the near-end slant range and the far-end slant range, and determines the imaging information corresponding to the imaging mode; and it performs spaceborne synthetic aperture radar imaging based on the wavefront imaging parameters, the gain control parameters, the sampling start, the sampling duration, and the imaging information.

[0183] 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.

[0184] 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.

[0185] 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 on-orbit autonomous 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 through analysis of the user's observation requirements. The orbit information is determined based on satellite forecast information. The imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbital altitude, downward 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 imaging parameter preset table, wavefront imaging parameters are determined, and based on the polarization mode and the target type, gain control parameters are determined. Based on the wavefront imaging parameters, the near-end slant range and the 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 far-end slant range. The imaging information corresponding to the imaging mode is also determined. Spaceborne synthetic aperture radar imaging is performed based on the wavefront imaging parameters, the gain control parameters, the sampling start, the sampling duration, and the imaging information.

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

3. The on-orbit autonomous mission planning method for spaceborne synthetic aperture radar according to claim 1, characterized in that, The steps for obtaining the imaging parameter preset table include: Based on orbital prediction information, the orbital altitude relative to sea level is determined; Based on the maximum value of the orbital altitude relative to sea level, determine the target maximum value of the equivalent orbital altitude; Based on the minimum orbital altitude relative to sea level and the maximum digital elevation of the ground, a target minimum of the equivalent orbital altitude is determined, and based on the target maximum and the target minimum, a range of equivalent orbital altitudes is determined. Based on the equivalent orbital altitude range, the imaging parameter preset table is determined.

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

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

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

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

8. A spaceborne synthetic aperture radar on-orbit autonomous mission planning device, characterized in that, include: The acquisition unit is used 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 through analysis of the user's observation requirements. The orbit information is determined based on satellite forecast information. The imaging parameter preset table reflects the imaging parameters set by the satellite imaging system under different conditions. The imaging parameter information includes orbital altitude, downward angle between the satellite imaging system and the target, polarization mode, target type, and imaging mode. The first determining unit is used to determine wavefront imaging parameters based on the orbital height, the downward viewing angle, the imaging mode, and the imaging parameter preset table, and to determine gain control parameters based on the polarization mode and the target type. The second determining unit is used to determine the near-end slant range and the far-end slant range based on the slant range of the slant view in the slant imaging parameters, determine the sampling start based on the near-end slant range, determine the sampling duration based on the near-end slant range and the far-end slant range, and determine the imaging information corresponding to the imaging mode. An imaging unit is used to perform spaceborne synthetic aperture radar imaging based on the wavefront imaging parameters, the gain control parameters, 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, it implements the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar 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 the processor, it implements the on-orbit autonomous mission planning method for spaceborne synthetic aperture radar as described in any one of claims 1 to 7.

Images