Target time window and target operation parameter determination method based on satellite

Abstract

The embodiment of the invention provides a satellite-based target time window and target operation parameter determination method, and the method comprises the steps: obtaining operation parameters of a target observation satellite for observing a target observation region and collecting observation data in a plurality of time windows, the target observation satellite passes through the target observation area in a plurality of time windows by adopting different operation parameters; determining observation strips of the target observation satellite in the plurality of time windows based on the operation parameters corresponding to the plurality of time windows; determining observation coverage areas corresponding to the plurality of time windows based on the observation strips in the plurality of time windows and the position information of the target observation area; and based on the observation coverage areas corresponding to the plurality of time windows, determining a target time window from the plurality of time windows and target operation parameters corresponding to the target time window. Therefore, screening of the target time window and the operation parameters is realized, the labor cost is reduced, and the observation efficiency and precision of the target observation area are improved.

Description

TECHNICAL FIELD

[0001] The embodiments of the present specification relate to the technical field of satellite remote sensing, and particularly relate to a target time window and target running parameter determination method based on a satellite. BACKGROUND

[0002] With the rapid development of satellite remote sensing technology, satellite earth observation applications are increasingly widespread, and the demand for accurate coverage of target observation areas is continuously increasing.

[0003] Currently, satellite observation task planning mainly relies on manual setting of time windows and fixed running parameters, and the coverage range for the target observation area is estimated through a basic geometric model. The target observation area is usually a polygon or circular area, which is relatively large compared to the range that can be observed by the satellite-borne sensor, making it impossible to be completely covered by a single observation or a single strip of the star-borne sensor, and multiple observations are needed to completely cover it.

[0004] In the above technical solution, the time window and the running parameter are set manually, which lacks systematic quantification and evaluation of the observation coverage area, cannot automatically compare and filter multiple time windows, and relies on manual trial and error. Multiple observations of the target observation area will result in additional consumption of satellite observation resources and low observation efficiency. Therefore, a more accurate and efficient target time window and running parameter determination method is urgently needed to improve the observation efficiency and coverage rate for the target observation area. SUMMARY

[0005] Therefore, the embodiments of the present specification provide a target time window and target running parameter determination method based on a satellite, which comprises:

[0006] Obtaining the running parameters of the target observation satellite for observing and collecting observation data on the target observation area in multiple time windows, wherein the target observation satellite adopts different running parameters to pass through the target observation area in multiple time windows;

[0007] Determining the observation strip of the target observation satellite in multiple time windows based on the running parameters corresponding to the multiple time windows;

[0008] Determining the observation coverage area corresponding to the multiple time windows based on the observation strip in the multiple time windows and the position information of the target observation area;

[0009] Determining the target time window from the multiple time windows and the target running parameter corresponding to the target time window based on the observation coverage area corresponding to the multiple time windows.

[0010] By accurately obtaining the observation and data collection operation parameters of the target observation satellite in multiple time windows, determining the observation strip based on the operation parameters, combining the position information of the target observation area to be observed, determining the observation coverage area that can be covered by the observation strip corresponding to the multiple time windows, and further determining the target time window and the corresponding target operation parameter based on the observation coverage area, the target time window and the corresponding operation parameter that meet the observation requirements for the target observation area are automatically identified and screened, the manual debugging cost is reduced, the observation efficiency for the target observation area is improved, and more accurate and efficient observation is realized. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a flowchart of a satellite-based target time window and target operation parameter determination method provided by an embodiment of the present specification;

[0012] Figure 2 is a schematic diagram of determining the near-end spherical distance and the far-end spherical distance according to the angular direction and size relationship between the near-end satellite side swing angle and the far-end satellite side swing angle provided by an embodiment of the present specification;

[0013] Figure 3 is a schematic diagram of the positional relationship between the strip center, the region center and the subsatellite point provided by an embodiment of the present specification;

[0014] Figure 4 is a schematic diagram of the positional relationship between the target observation area and the observation strip when the first distance is greater than the sum of the region radius and the strip half-width provided by an embodiment of the present specification;

[0015] Figure 5 is a schematic diagram of the positional relationship between the target observation area and the observation strip when the first distance is less than the difference between the region radius and the strip half-width provided by an embodiment of the present specification;

[0016] Figure 6 is a schematic diagram of the positional relationship between the target observation area and the observation strip when the region radius is greater than the strip half-width, and the first distance is less than the difference between the region radius and the strip half-width provided by an embodiment of the present specification;

[0017] Figure 7 is a schematic diagram of the positional relationship between the target observation area and the observation strip when the first distance is greater than the difference between the region radius and the strip half-width and less than the strip half-width provided by an embodiment of the present specification;

[0018] Figure 8is a schematic diagram of a position relationship between a target observation area and an observation strip in a case where a first distance is greater than a strip half-width and less than a sum of a region radius and the strip half-width, provided by one embodiment of the present specification;

[0019] Figure 9 is a schematic diagram of a position relationship of a determination of an imaging side swing angle, provided by one embodiment of the present specification;

[0020] Figure 10 is a schematic diagram of a position relationship of a determination of a near-end region side swing angle and a far-end region side swing angle, provided by one embodiment of the present specification;

[0021] Figure 11 is a schematic diagram of a position relationship of a single side swing observation, provided by one embodiment of the present specification;

[0022] Figure 12 is a schematic diagram of a position relationship of a double side swing observation, provided by one embodiment of the present specification;

[0023] Figure 13 is a flowchart of a target observation task execution method, provided by one embodiment of the present specification;

[0024] Figure 14 is a schematic diagram of a structure of a satellite system, provided by one embodiment of the present specification. DETAILED DESCRIPTION

[0025] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present specification. However, the present specification can be practiced without the specific details, other than in the examples, and it is understood that the scope of the present specification is not limited to the details below.

[0026] The terminology used in one or more embodiments of the present specification is for the purpose of describing particular embodiments only and is not intended to be limiting of one or more embodiments of the present specification. As used in one or more embodiments of the present specification and the accompanying claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in one or more embodiments of the present specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0027] It should be understood that, although the terms first, second, etc. can be employed in describing various information in one or more embodiments of the present specification, the information should not be limited to such terms. These terms are only used to differentiate one piece of information from another piece of information of the same type. For example, without departing from the scope of one or more embodiments of the present specification, first can also be referred to as second, and similarly, second can also be referred to as first. Depending on the context, the word "if' as used herein can be interpreted as "when" or "upon" or "in response to determining".

[0028] In addition, it should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in one or more embodiments of the present specification are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation portal for user to choose authorization or refusal.

[0029] Firstly, the nomenclature involved in one or more embodiments of the present specification is explained.

[0030] Agile Satellite is a satellite with rapid attitude adjustment capability, which can quickly scan point targets such as cities or airports by adjusting the observation angle and position within a limited transit time.

[0031] Synthetic Aperture Radar Satellite (SAR Satellite) is a satellite equipped with a synthetic aperture radar system, which actively transmits and receives radar signals to achieve high-resolution, all-weather, and full-time observation of the earth's surface, suitable for large-scale regional target monitoring tasks.

[0032] Spaceborne Sensor is a detection device installed on a satellite, used to collect remote sensing data of target areas, such as optical imaging sensors, infrared sensors or synthetic aperture radars, whose performance directly determines the accuracy and coverage capability of satellite observation.

[0033] Single Beam (SB) refers to the observation mode of spaceborne sensors using a single direction to transmit and receive signals, which is usually used in single-side observation scenarios, such as adjusting the side swing angle to the left or right to form a single-side observation strip, suitable for regional coverage requirements in a specific direction.

[0034] Dual Beam (DB) refers to an observation mode of a spaceborne sensor that transmits and receives signals in two independent directions at the same time, which is usually used in a double-side swing observation scenario, for example, adjusting the side swing angle to the left and right sides at the same time to form a double-side observation strip, and is suitable for tasks that require expansion of single coverage range.

[0035] In the present specification, a satellite-based target time window and target running parameter determination method is provided. One or more embodiments of the present specification also relate to a target observation task execution method and a satellite system, which are described in detail in the following embodiments.

[0036] Referring to Figure 1 , Figure 1 A flowchart of a satellite-based target time window and target running parameter determination method according to one embodiment of the present specification is shown, which specifically includes the following steps.

[0037] Step 102: Obtain the running parameters of the target observation satellite for observing and collecting observation data of the target observation area in multiple time windows, wherein the target observation satellite adopts different running parameters to pass through the target observation area in multiple time windows.

[0038] The satellite-based target time window and target running parameter determination method provided by one or more embodiments of the present specification can be applied to satellite observation tasks in a single-satellite scenario, especially for the observation of circular area targets. It can be applied to agile satellites, SAR satellites and other systems. The observed target observation area can be an area on the surface of the earth (such as a city, a mountain, etc.), or an area on the surface of other celestial bodies (such as a crater on the surface of the moon, a canyon on the surface of Mars, etc.). The present embodiments do not make specific limitations on this.

[0039] The target observation satellite is a satellite used for observing and collecting data of a specific target observation area. The target observation satellite can carry a spaceborne sensor to observe the target observation area to be observed with specific running parameters in a specific time window during the orbit around a specific celestial body (such as the earth, the moon, etc.). Specifically, the target observation satellite can be an agile satellite or a synthetic aperture satellite in a single-satellite observation scenario, and the observation strip can be changed by adjusting the satellite side swing angle and determining the sub-satellite point position with different running orbits.

[0040] The time window is a specific time period in which the satellite can observe and collect observation data for a specific target observation area during the orbit operation. The time window can be determined by the orbit position of the target observation satellite, the position information of the target observation area, and the maneuvering capability of the target observation satellite, etc. Specifically, the time window can be a specific time period when the target observation satellite passes through the target observation area, for example, the target observation satellite can continuously observe the target observation area within a preset time range (such as 24 hours) each time it passes through the space above the target observation area. The determination of the time window can be based on the running parameters of the target observation satellite and the geographical position and range of the target observation area.

[0041] The target observation area is a specific geographical area that needs to be observed by the target observation satellite, such as a mountain range, a city, etc., which can usually be a circular or polygonal area, the size and position of which determine the difficulty of observation and the required running parameters of the target observation satellite. Specifically, the target observation area can be described as a circular area to simplify the calculation process, and accordingly, the region center coordinates (such as latitude and longitude) and the region radius of the target observation area need to be determined.

[0042] The observation data is the image or remote sensing data collected by the target observation satellite through the on-board sensor after observing the target observation area, which is used for subsequent analysis and processing. Specifically, the observation data can be the original data obtained by the target observation satellite observing the target observation area under specific running parameters, which are the basis for determining the observation coverage area and calculating the optimal running parameters, such as satellite image data collected by the satellite under specific time windows and running parameters, which are used to evaluate the coverage effect under the observation condition.

[0043] The running parameter is a specific configuration parameter used by the target observation satellite during observation, which reflects the running information of the target observation satellite in the current time window, and can include the subsatellite point, satellite roll angle, satellite altitude, etc. determined based on the running orbit of the current time window. The running parameter determines the shape, size and position of the observation strip when the target observation satellite is observing.

[0044] Different running parameters are different running parameter configurations adopted by the target observation satellite in different time windows, and these configuration differences result in different observation strips, which affect the coverage effect of the target observation area. Specifically, since the running orbit of the target observation satellite can be maneuvered with running time, the roll angle of the on-board sensor of the target observation satellite can also be adjusted, therefore, in different time windows, the subsatellite point and satellite altitude of the target observation satellite, the satellite roll angle adopted, the speed flown, etc. can be different. Different combinations of running parameters can achieve observation coverage effect evaluation under different observation conditions, so as to determine the optimal observation scheme.

[0045] In the process of the target observation satellite running along the running track, the observation data can be collected in the time window in which the target observation region can be observed and observation data can be collected, and in the process of collecting the observation data, the running parameters of the target observation satellite in the multiple time windows can be recorded synchronously.

[0046] For the acquisition of the running parameters, the running parameters transmitted back by the target observation satellite in real time can be received, and the running parameters can also be acquired from a local storage system, a cloud storage system, etc.

[0047] In this step, by acquiring the running parameters of the target observation satellite for observing the target observation region in multiple time windows using different running parameters, a data basis is provided for subsequent determination of the target time window and the target running parameter, so that the target time window can be determined based on actual observation data rather than theoretical speculation, the observation scheme is optimized, and the maximum coverage of the target observation region is ensured within the limited transit time, thereby improving the efficiency and accuracy of the satellite observation task.

[0048] Step 104: Based on the running parameters corresponding to the multiple time windows, the observation strips of the target observation satellite in the multiple time windows are determined.

[0049] The observation strip is a specific geometric shape and size of the observation range formed on the surface of the celestial body being orbited when the target observation satellite observes through the on-board sensor under specific running parameters. The observation strip can be determined by the sub-satellite point position, satellite side-slip angle and satellite altitude of the target observation satellite, and can be expressed as a band-shaped region with a center line parallel to the satellite running track direction, and the key features can include the strip center and the strip half-width, wherein the strip center represents the center line position of the observation strip, and the strip half-width represents half of the observation strip width, and the geometric characteristics of the observation strip can be described by the two key features.

[0050] Optionally, the observation on-board sensor of the target observation satellite can be a single-beam sensor, and the observation strip corresponds to one strip; the on-board sensor of the target observation satellite can also be a double-beam sensor, and the corresponding observation strip is two strips. Specifically, based on the running parameters corresponding to the multiple time windows, the observation strips of the target observation satellite in the multiple time windows can be determined respectively.

[0051] For any time window, the strip half-width of the observation strip can be determined according to the sub-satellite point and the satellite side-slip angle of the target observation satellite in the running parameters of the time window, and the strip center can be determined based on the strip half-width, so as to determine the observation strip.

[0052] Optionally, the distance from the observation range boundary to the subsatellite point of the target observation satellite, i.e., the spherical distance, can be determined based on the subsatellite point and the satellite side swing angle of the target observation satellite, as well as the satellite altitude. In the case of determining the spherical distance, the strip half-width can be further determined in combination with the directionality of the satellite side swing angle.

[0053] In an actual observation scenario, the satellite side swing angle of the target observation satellite can be symmetrically distributed on both sides of the subsatellite point, i.e., the strip center of the observation strip coincides with the subsatellite point of the target observation satellite, in which case the satellite side swing angle does not need to be calculated separately; the satellite side swing angle of the target observation satellite can also be asymmetrically distributed on both sides of the subsatellite point, in which case the satellite side swing angle needs to be divided into near-end satellite side swing angle and far-end satellite side swing angle according to the distance from the observation range boundary to the subsatellite point, and the distance from the observation range boundary to the subsatellite point is calculated respectively.

[0054] Optionally, in the case of determining the observation strip, the distance from the strip center of the observation strip to the subsatellite point can be further determined to determine the accurate coordinates of the observation strip based on the known subsatellite point coordinates.

[0055] In this step, the observation strip of the target observation satellite in the multiple time windows is accurately determined based on the running parameters corresponding to the multiple time windows, which provides a geometric basis for subsequent calculation of observation coverage area and determination of optimal observation scheme, so that the influence of different running parameters on observation coverage effect can be accurately evaluated, thereby providing a scientific basis for selecting the best time window and running parameter, and effectively improving the planning accuracy and execution efficiency of satellite observation tasks.

[0056] Step 106: Based on the observation strips in the multiple time windows and the position information of the target observation area, the observation coverage areas corresponding to the multiple time windows are determined.

[0057] The position information of the target observation area is a geographical position description of the target observation area on the surface of the earth or other celestial bodies, including data such as the area center coordinates (e.g., latitude and longitude) and the area radius of the target observation area, and the position information of the target observation area can be used to determine the relative position relationship between the target observation area and the observation strip of the target observation satellite, thereby calculating the observation coverage area.

[0058] The observation coverage area is the size of the target observation area actually covered by the target observation satellite through the star-borne sensor when observing the target observation area under a specific time window and operation parameter. Specifically, the observation coverage area can be determined by the relative position relationship between the observation strip and the target observation area. It can be complete coverage, that is, the coverage area is equal to the target observation area, that is, the target observation area is completely located in the observation strip. It can also be partial coverage, that is, the observation coverage area is smaller than the target observation area, that is, the target observation area is partially located in the observation strip. It can also be uncovered, that is, the observation coverage area is zero, that is, the target observation area is completely located outside the observation strip.

[0059] After the observation strip is determined, the observation coverage area can be determined based on the position information of the observation strip and the target observation area. Specifically, the position relationship between the observation strip and the target observation area can be determined, and the observation coverage area can be calculated based on the position relationship. The position relationship can include complete coverage, partial coverage or no coverage. The method of determining the position relationship can be based on the distance between the region center of the target observation area and the strip center of the observation strip, and the size relationship between the strip half-width and the region radius. For example, if the distance between the region center and the observation strip is greater than the sum of the region radius and the strip half-width, it indicates that the target observation area is completely located outside the observation strip, and the coverage area is zero. If the distance between the region center and the observation strip is less than the difference between the region radius and the strip half-width, it indicates that the target observation area is completely located in the observation strip, and the coverage area is equal to the target observation area. If the distance between the region center and the observation strip is greater than the difference between the region radius and the strip half-width and less than the sum of the region radius and the strip half-width, it indicates that the target observation area is partially located in the observation strip, and the coverage area is the intersection area of the two.

[0060] After the position relationship between the observation strip and the target observation area is determined, the observation coverage area can be determined through geometric calculation, and the observation coverage area of the observation coverage area can be calculated.

[0061] In this step, the observation coverage area corresponding to each time window is calculated based on the position information of the observation strip and the target observation area in multiple time windows, which provides a quantitative basis for determining the target time window and the target operation parameter based on the observation coverage area. It can objectively evaluate the coverage effect under different observation conditions, so as to select the time window and operation parameter with the largest coverage area, effectively improving the planning accuracy and execution efficiency of satellite observation task.

[0062] Step 108: determining the target time window and the target operation parameter corresponding to the target time window from multiple time windows based on the observation coverage area corresponding to multiple time windows.

[0063] The target time window is a specific time period selected from the multiple time windows by comparing the observation coverage areas corresponding to the time windows. The target time window can enable the target observation satellite to achieve the maximum coverage effect for the target observation area, and is the core of achieving the optimal observation effect in the execution of the satellite observation task.

[0064] The target running parameter corresponding to the target time window is a running parameter of the target observation satellite in the target time window. The target running parameter can enable the target observation satellite to achieve the maximum coverage effect for the target concept vehicle area. The target running parameter can include an imaging side swing angle determined based on the observation coverage area, so as to specify the specific side swing angle of the satellite-borne sensor of the target observation satellite in the target time window for observation, so as to achieve efficient use of imaging resources.

[0065] In the case where the observation coverage areas corresponding to the multiple target time windows are determined, the target time window can be determined based on the observation coverage areas. Specifically, the time window with the largest coverage area can be selected as the target time window by comparing the sizes of the observation coverage areas corresponding to the time windows.

[0066] Alternatively, if the sizes of the observation coverage areas corresponding to the multiple time windows are the same, for example, the target observation area is completely located in the observation strip in the multiple time windows, in this case, any one of the time windows can be randomly selected as the target time window, or the actual running orbit of the target observation satellite or the observation task for other observation areas can be combined to determine, so as to achieve the balance of the observation load of the target observation satellite.

[0067] In the embodiments of the present specification, by accurately obtaining the running parameters of the target observation satellite in the multiple time windows for observation and data collection, the observation strip is determined based on the running parameters, the position information of the target observation area to be observed is combined to determine the observation coverage area covered by the observation strip corresponding to the multiple time windows, and the target time window and the corresponding target running parameter are further determined from the multiple time windows based on the observation coverage area, so as to automatically identify and select the target time window and the corresponding running parameter for the target observation area that meet the observation result requirements, reduce the manual debugging cost, improve the observation efficiency for the target observation area, and achieve more accurate and efficient observation.

[0068] In an optional embodiment of the present specification, the running parameter includes a subsatellite point and a satellite side swing angle; and the observation strip of the target observation satellite in the multiple time windows is determined based on the running parameters corresponding to the multiple time windows, including: the observation strip of the target observation satellite in the multiple time windows is determined based on the subsatellite points and the satellite side swing angles corresponding to the multiple time windows.

[0069] The subsatellite point is a point on the surface of a celestial body (such as the Earth) directly below the target observation satellite during the orbiting process of the satellite, that is, the intersection of the line connecting the satellite and the center of the sphere and the sphere, which can describe the projection position of the target observation satellite on the surface of the celestial body. The coordinate value of the subsatellite point directly affects the position of the observation strip, that is, in the process of determining the observation strip, the subsatellite point is the reference basis for calculating the center position of the observation strip, and the latitude and longitude coordinates of the subsatellite point determine the accurate position of the observation strip on the surface of the celestial body.

[0070] The satellite side swing angle is an angle at which a starboard sensor for observation and imaging of the target observation satellite swings laterally relative to the orbit direction of the satellite during the orbiting process of the satellite, which is used to adjust the direction and width of the observation strip. Specifically, the satellite side swing angle can be symmetrically distributed on both sides of the subsatellite point, or asymmetrically distributed on both sides of the subsatellite point.

[0071] In the case where the running parameters corresponding to the plurality of time windows are obtained, the observation strip of the target observation satellite in the plurality of time windows can be further determined based on the subsatellite point and the satellite side swing angle included in the running parameters corresponding to the plurality of time windows. Specifically, for any time window, the strip half-width of the observation strip can be calculated based on the subsatellite point coordinate and the satellite side swing angle in the running parameter; and the observation strip is determined according to the strip half-width.

[0072] When the satellite side swing angle is symmetrically distributed on both sides of the subsatellite point, the strip center of the observation strip coincides with the subsatellite point, and there is no need to distinguish between the near-end and far-end satellite side swing angles; when the satellite side swing angle is asymmetrically distributed on both sides of the subsatellite point, the satellite side swing angle needs to be divided into the near-end satellite side swing angle and the far-end satellite side swing angle, and the distance of the observation range of each from the subsatellite point is calculated respectively, so as to accurately determine the geometric characteristics of the observation strip.

[0073] In the embodiments of the present specification, the observation strip of the target observation satellite in the plurality of time windows is determined based on the subsatellite point and the satellite side swing angle corresponding to the plurality of time windows, which provides an accurate geometric basis for subsequent calculation of the observation coverage area and determination of the optimal observation scheme, so that the influence of different running parameters on the observation coverage effect can be accurately evaluated, thereby providing a scientific basis for selecting the best time window and running parameter, and effectively improving the planning accuracy and execution efficiency of the satellite observation task.

[0074] In an optional embodiment of the present disclosure, the running parameters further include a satellite altitude, the satellite roll angle includes a near-end satellite roll angle and a far-end satellite roll angle; and the determining of the observation swath of the target observation satellite in the plurality of time windows based on the plurality of time windows corresponding to the subsatellite points and the satellite roll angle includes: determining a plurality of time windows corresponding to the near-end spherical distances based on the satellite altitude and the plurality of time windows corresponding to the near-end satellite roll angles, and determining a plurality of time windows corresponding to the far-end spherical distances based on the satellite altitude and the plurality of time windows corresponding to the far-end satellite roll angles; determining a plurality of time windows corresponding to the swath half-widths based on the angular directionality between the plurality of time windows corresponding to the near-end satellite roll angles and the plurality of time windows corresponding to the far-end satellite roll angles, and the plurality of time windows corresponding to the near-end spherical distances and the plurality of time windows corresponding to the far-end spherical distances; and determining the observation swath of the target observation satellite in the plurality of time windows based on the plurality of time windows corresponding to the swath half-widths.

[0075] The satellite altitude is a vertical distance between the satellite and the earth surface during the orbiting of the target observation satellite, and can be used to determine the observation range boundary of the spaceborne sensor on the ground, i.e., the distance from the swath boundary of the observation swath to the subsatellite point. In the process of determining the observation swath, the satellite altitude can determine the swath boundary of the observation swath together with the satellite roll angle.

[0076] The near-end satellite roll angle is a roll angle on the side closer to the subsatellite point in the satellite roll angle, and is used to calculate the near-end spherical distance from the observation range boundary to the subsatellite point. In the case that the satellite roll angle is asymmetrically distributed on both sides of the subsatellite point, the near-end satellite roll angle is the part of the satellite roll angle close to the subsatellite point, and the angle value thereof determines the distance from the near-end swath boundary of the observation swath to the subsatellite point.

[0077] The far-end satellite roll angle is a roll angle on the side farther from the subsatellite point in the satellite roll angle, and is used to calculate the far-end spherical distance from the observation range boundary to the subsatellite point. In the case that the satellite roll angle is asymmetrically distributed on both sides of the subsatellite point, the far-end satellite roll angle is the part of the satellite roll angle far from the subsatellite point, and the angle value thereof determines the distance from the far-end swath boundary of the observation swath to the subsatellite point.

[0078] The near-end spherical distance is determined based on the satellite altitude and the near-end satellite roll angle, and is the spherical distance from the observation range boundary of the spaceborne sensor on the ground to the subsatellite point, representing the arc length distance from the near-end swath boundary of the observation swath to the subsatellite point, and can be used to describe the geometric characteristics of the observation swath.

[0079] The far-end spherical distance is determined based on the satellite altitude and the far-end satellite yaw angle, is the spherical distance from the observation range boundary on the ground to the subsatellite point, and represents the arc length distance from the far-end strip boundary of the observation strip to the subsatellite point, which can be used to describe the geometric characteristics of the observation strip.

[0080] In the process of determining the strip half-width of the observation strip, the difference or sum of the near-end spherical distance and the far-end spherical distance can be used for determination.

[0081] The angular directionality is the relative directional relationship between the near-end satellite yaw angle and the far-end satellite yaw angle relative to the subsatellite point at any time window, which can represent whether the near-end satellite yaw angle and the far-end satellite yaw angle are distributed on the same side or on the opposite side of the subsatellite point, so as to determine the calculation method of the strip half-width.

[0082] Specifically, when the angular directionality is the same, the strip half-width can be calculated based on the difference between the near-end spherical distance and the far-end spherical distance; when the angular directionality is opposite, the strip half-width can be calculated based on the sum of the near-end spherical distance and the far-end spherical distance.

[0083] The strip half-width is half of the observation strip width, represents the transverse width of the observation strip, and can be used to describe the geometric characteristics of the observation strip to determine the range of the observation strip. The size of the strip half-width can directly affect the calculation of the observation coverage area.

[0084] The strip center is the center line position of the observation strip, represents the center of the observation strip, and can be used to describe the position of the observation strip, i.e., the position of the strip center determines the position of the observation strip on the celestial body surface. The complete geometric shape of the observation strip can be determined by the strip center and the strip half-width.

[0085] After the satellite altitude, the near-end satellite yaw angle, and the far-end satellite yaw angle corresponding to a plurality of time windows are determined, the near-end spherical distance can be determined based on the satellite altitude and the near-end satellite yaw angle, and the far-end spherical distance can be determined based on the satellite altitude and the far-end satellite yaw angle. Specifically, the near-end spherical distance and the far-end spherical distance can be calculated by using trigonometric functions (such as the sine theorem), and the strip half-width can be further determined based on the angular directionality of the near-end satellite yaw angle and the far-end satellite yaw angle.

[0086] After the strip half-width is determined, the strip center can be determined, and the observation strip in the plurality of time windows can be further determined based on the second distance from the strip center to the subsatellite point.

[0087] Optionally, after the strip center is determined, the strip center yaw angle of the target observation satellite to the strip center can be further determined based on the subsatellite point.

[0088] For example, the method will be further explained by taking the execution of an observation task for a target observation area on the Earth's surface as an example.

[0089] The distance to the far spherical surface, determined based on the satellite altitude and the near-end satellite's side yaw angle, can be expressed as:

[0090] W1 = R e ×(arcsin((R e +H) / R e ×sin(|α fmax |))-|α fmax |)

[0091] Among them, R e Let α be the Earth's radius, H be the altitude of the target observation satellite, and α be the Earth's radius. fmax Let W1 be the far-end side-swing angle and W2 be the far-end spherical distance. Correspondingly, the near-end spherical distance, determined based on the satellite altitude and the far-end satellite side-swing angle, can be expressed as:

[0092] W2 = R e ×(arcsin((R e +H) / R e ×sin(|α fmin |))-|α fmin |)

[0093] Among them, R e Let α be the Earth's radius, H be the altitude of the target observation satellite, and α be the Earth's radius. fmin Let W1 be the proximal lateral swing angle, and W2 be the proximal spherical distance. Then the half-width W of the strip can be expressed as:

[0094]

[0095] Correspondingly, the second distance L from the center of the strip to the sub-satellite point can be expressed as:

[0096]

[0097] Correspondingly, the center-side sway angle α0 of the strip can be expressed as:

[0098]

[0099] In the embodiments of the present specification, the near-end spherical distance and the far-end spherical distance are determined based on the near-end satellite roll angle and the far-end satellite roll angle corresponding to the satellite altitude and the plurality of time windows, and the strip half-width is calculated based on the angle directionality between the near-end satellite roll angle and the far-end satellite roll angle, and the near-end spherical distance and the far-end spherical distance corresponding to the plurality of time windows, and the strip center, so that the position information and the geometric characteristics of the observation strip can be accurately calculated, which provides an accurate geometric basis for subsequent calculation of the observation coverage area and determination of the optimal observation scheme, and effectively improves the planning accuracy and execution efficiency of the satellite observation task.

[0100] In an optional embodiment of the present specification, the strip half-width corresponding to the plurality of time windows is determined based on the angle directionality between the near-end satellite roll angle corresponding to the plurality of time windows and the far-end satellite roll angle corresponding to the plurality of time windows, and the near-end spherical distance corresponding to the plurality of time windows and the far-end spherical distance corresponding to the plurality of time windows, including: in the case that the angle directionality between the near-end satellite roll angle corresponding to the plurality of time windows and the far-end satellite roll angle corresponding to the plurality of time windows is the same direction, the strip half-width corresponding to the plurality of time windows is determined based on the difference between the near-end spherical distance corresponding to the plurality of time windows and the far-end spherical distance corresponding to the plurality of time windows; in the case that the angle directionality between the near-end satellite roll angle corresponding to the plurality of time windows and the far-end satellite roll angle corresponding to the plurality of time windows is the opposite direction, the strip half-width corresponding to the plurality of time windows is determined based on the sum of the near-end spherical distance corresponding to the plurality of time windows and the far-end spherical distance corresponding to the plurality of time windows.

[0101] Specifically, the angle directionality between the near-end satellite roll angle and the far-end satellite roll angle can include the same direction of the near-end satellite roll angle and the far-end satellite roll angle, and the opposite direction of the near-end satellite roll angle and the far-end satellite roll angle.

[0102] The same direction of the near-end satellite roll angle and the far-end satellite roll angle means that the near-end satellite roll angle and the far-end satellite roll angle are both located on the same side of the subsatellite point, and then the subsatellite point of the target observation satellite is located outside the observation strip, at this time the strip half-width should be the difference between the far-end spherical distance and the near-end spherical distance, because the strip width is the distance between the two boundaries; the opposite direction of the near-end satellite roll angle and the far-end satellite roll angle means that the near-end satellite roll angle and the far-end satellite roll angle are distributed on both sides of the subsatellite point, and then the target observation satellite is located within the observation strip, at this time the strip half-width should be the sum of the near-end spherical distance and the far-end spherical distance, because the strip width is the sum of the distances from the two boundaries to the subsatellite point.

[0103] Optionally, in the case that the angle directionality between the near-end satellite roll angle and the far-end satellite roll angle is determined, the strip half-width can be further determined based on the angle size relationship between the near-end satellite roll angle and the far-end satellite roll angle.

[0104] Optionally, given the angular relationship between the near-satellite side swing angle and the far-satellite side swing angle, a second distance from the nadir point to the strip center, as well as the strip center side swing angle, can be further determined.

[0105] For example, continuing with the previous example, this method will be further explained by taking the execution of an observation task for a target observation area on the Earth's surface as an example.

[0106] See Figure 2 , Figure 2 This diagram illustrates a method for determining the near-spherical distance and the far-spherical distance based on the angular directionality and magnitude relationship between the near-spherical side angle and the far-spherical side angle, according to an embodiment of this specification.

[0107] If the angular directionality between the near-end satellite side-swing angle and the far-end satellite side-swing angle is opposite, and the magnitude relationship between the near-end satellite side-swing angle and the far-end satellite side-swing angle is that the far-end satellite side-swing angle is greater than or equal to the near-end satellite side-swing angle, that is:

[0108] α fmax >0,α fmin <0,|α fmax |≥|α fmin |

[0109] Where, α fmin It is the near-satellite side yaw angle, α fmax It is the side tilt angle of the remote satellite.

[0110] The diagram illustrating the determination of the proximal and distal spherical distances is shown below. Figure 2 As shown in Figure a, the half-width of the strip can be expressed as:

[0111]

[0112] Correspondingly, the second distance from the center of the strip to the sub-satellite point can be expressed as:

[0113]

[0114] Correspondingly, the center lateral sway angle of the strip can be expressed as:

[0115]

[0116] If the angular directions of the near-end satellite side glide angle and the far-end satellite side glide angle are opposite, and the magnitudes of the near-end satellite side glide angle and the far-end satellite side glide angle are such that the far-end satellite side glide angle is smaller than the near-end satellite side glide angle, that is:

[0117] α fmax >0,α fmin <0,|α fmax |<|α fmin|

[0118] wherein α fmin is the near-end satellite yaw angle, α fmax is the far-end satellite yaw angle.

[0119] The determination of the near-end spherical distance and the far-end spherical distance is shown in FIG. 3B. The strip half-width can be expressed as: Figure 2

[0120]

[0121] Correspondingly, the second distance from the strip center to the subsatellite point can be expressed as:

[0122]

[0123] Correspondingly, the strip center yaw angle can be expressed as:

[0124]

[0125] If the angle directionality between the near-end satellite yaw angle and the far-end satellite yaw angle is the same direction, and the size relationship between the near-end satellite yaw angle and the far-end satellite yaw angle is that the far-end satellite yaw angle is greater than or equal to the near-end satellite yaw angle, that is:

[0126] α fmin ≥ 0

[0127] wherein α fmin is the near-end satellite yaw angle.

[0128] The determination of the near-end spherical distance and the far-end spherical distance is shown in FIG. 3C. The strip half-width can be expressed as: Figure 2

[0129]

[0130] Correspondingly, the second distance from the strip center to the subsatellite point can be expressed as:

[0131]

[0132] Correspondingly, the strip center yaw angle can be expressed as:

[0133]

[0134] If the angle directionality between the near-end satellite yaw angle and the far-end satellite yaw angle is the same direction, and the size relationship between the near-end satellite yaw angle and the far-end satellite yaw angle is that the far-end satellite yaw angle is greater than or equal to the near-end satellite yaw angle, that is:

[0135] α fmax ≤ 0 ​​

[0136] wherein a fmax is the far-end satellite side-slip angle.

[0137] The determination schematic diagram of the near-end spherical distance and the far-end spherical distance is shown in FIG. a of Figure 2 The strip half-width can be represented as:

[0138]

[0139] Correspondingly, the second distance from the strip center to the subsatellite point can be represented as:

[0140]

[0141] Correspondingly, the strip center side-slip angle can be represented as:

[0142]

[0143] In the embodiments of the present specification, by selecting the corresponding strip half-width calculation method based on the angular directionality between the near-end satellite side-slip angle and the far-end satellite side-slip angle, that is, using the difference value to calculate the strip half-width in the case that the near-end satellite side-slip angle and the far-end satellite side-slip angle are in the same direction, and using the sum value to calculate the strip half-width in the case that the near-end satellite side-slip angle and the far-end satellite side-slip angle are in different directions, the geometric characteristics of the observation strip can be accurately calculated based on the actual operation of the target observation satellite, which provides an accurate geometric basis for subsequent observation coverage area calculation and optimal observation scheme determination, thereby effectively improving the planning accuracy and execution efficiency of the satellite observation task.

[0144] In an optional embodiment of the present specification, the running parameters include a subsatellite point and a satellite side-slip angle, the position information of the target observation region includes a region center and a region radius of the target observation region, and the observation strip includes a strip center and a strip half-width; based on the observation strips in the multiple time windows and the position information of the target observation region, the observation coverage areas corresponding to the multiple time windows are determined, including: determining a first distance between the region center and the strip center of the observation strip in the multiple time windows; and calculating the observation coverage areas of the observation strips in the multiple time windows on the target observation region according to the first distance, the region radius and the strip half-width of the observation strip.

[0145] The region center is the geometric center point position of the target observation region on a specific celestial body surface, which can be usually represented in the form of latitude and longitude coordinates, and is used to describe the center position of the target observation region. Specifically, the region center is a reference point for determining the relative position relationship between the target observation region and the observation strip. The region radius is the straight-line distance from the region center to the boundary point of the target observation region, which can be used to describe the size range of the target observation region and is an important parameter for calculating the observation coverage area.

[0146] The first distance is a spherical distance between the region center of the target observation area and the strip center of the observation strip, and can describe the relative position relationship between the target observation area and the observation strip. The first distance can be used to determine the observation coverage area. For example, when the distance between the region center and the strip center is 5 kilometers, the region radius is 10 kilometers, and the strip half-width is 20 kilometers, the first distance is less than the difference between the region radius and the strip half-width, indicating that the target observation area is completely located in the observation strip. When the first distance is 35 kilometers, which is greater than the sum of the region radius and the strip half-width, it indicates that the target observation area and the observation strip are completely not overlapped.

[0147] When the strip half-width and the strip center of the observation strip are determined based on the running parameters, and the coordinates of the region center and the region radius of the target observation area are obtained, the first distance between the strip center and the region center can be determined.

[0148] Specifically, when the sub-satellite point coordinates and the region center coordinates are determined, the distance between the sub-satellite point and the region center can be determined based on the sub-satellite point coordinates and the region center coordinates, and the distance between the strip center and the region center can be further determined in combination with the distance between the sub-satellite point and the strip center, so as to determine the position relationship between the observation strip and the target observation area.

[0149] Further, when the first distance is determined, the observation coverage area can be calculated according to the size relationship among the first distance, the region radius and the strip half-width of the observation strip.

[0150] Specifically, when the first distance is less than the difference between the region radius and the strip half-width, it indicates that the target observation area is completely located in the observation strip, and the observation coverage area is equal to the total area of the target observation area. When the first distance is greater than the sum of the region radius and the strip half-width, it indicates that the target observation area is completely located outside the observation strip, and the observation coverage area is zero. When the first distance is between the difference between the region radius and the strip half-width and the sum of the region radius and the strip half-width, it indicates that the target observation area is partially located in the observation strip, and the observation coverage area is the intersection area of the target observation area and the observation strip. Specifically, the intersection area can be accurately determined by a geometric calculation method.

[0151] In the embodiments of the present specification, the first distance between the region center and the strip center is determined, and the observation coverage area is calculated based on the first distance, the region radius and the strip half-width of the observation strip, so as to accurately evaluate the coverage effect of the target observation area under different time windows, to provide a data basis for selecting the optimal target time window and target running parameters, thereby improving the planning accuracy and execution efficiency of the satellite observation task, and ensuring the maximized coverage of the target observation area within the limited transit time.

[0152] In an optional embodiment of the present disclosure, the running parameters further include a satellite altitude, and the satellite roll angle includes a near-end satellite roll angle and a far-end satellite roll angle; before determining the first distance between the region center and the strip center of the observation strip in the plurality of time windows, the method further comprises: calculating a second distance between the subsatellite point and the strip center of the observation strip based on a near-end spherical distance and a far-end spherical distance, wherein the near-end spherical distance is determined based on the satellite altitude and the near-end satellite roll angle, and the far-end spherical distance is determined based on the satellite altitude and the far-end satellite roll angle; calculating a strip center roll angle based on the second distance and the satellite altitude; and determining the first distance between the region center and the strip center of the observation strip in the plurality of time windows comprises: calculating a third distance between the region center and the subsatellite point based on the latitude and longitude of the region center and the latitude and longitude of the subsatellite point, and a region center roll angle between the target observation satellite and the region center; and determining the first distance between the region center and the strip center of the observation strip in the plurality of time windows according to the size relationship between the strip center roll angle and the region center roll angle.

[0153] The second distance is a spherical distance between the subsatellite point and the strip center of the observation strip, which can be used to describe the relative position relationship between the subsatellite point and the strip center of the observation strip, to determine the position of the observation strip on the celestial body surface, and further determine the strip center roll angle of the satellite to the strip center. Specifically, the second distance can be calculated by the near-end spherical distance and the far-end spherical distance.

[0154] The strip center roll angle is an angle parameter calculated based on the second distance and the satellite altitude, which can be used to describe the lateral offset angle of the observation strip center relative to the satellite orbit direction. Specifically, the strip center roll angle can be calculated by a trigonometric function. The strip center roll angle and the region center roll angle are used together to determine the first distance between the region center and the strip center of the observation strip, so as to evaluate the relative position relationship between the target observation region and the observation strip.

[0155] The third distance is a spherical distance between the region center of the target observation region and the subsatellite point, which can be used to describe the relative position relationship between the center point of the target observation region and the subsatellite point. Specifically, the third distance can be obtained by calculating the spherical distance between the coordinates of the region center and the coordinates of the subsatellite point, and is used for subsequent determination of the first distance between the region center and the strip center of the observation strip, to ensure accurate calculation of the relative position relationship between the target observation region and the observation strip.

[0156] The center-side swing angle is an angle between the target observation satellite and the regional center, and can be used to describe the lateral deviation angle of the regional center relative to the satellite orbit direction. Specifically, the center-side swing angle can be obtained by calculating the relative position relationship between the regional center coordinates and the subsatellite point coordinates. The center-side swing angle is used together with the strip center-side swing angle to determine the first distance between the regional center and the strip center of the observation strip, so as to accurately determine the relative position relationship between the target observation region and the observation strip.

[0157] After the near-end satellite-side swing angle and the far-end satellite-side swing angle included in the satellite-side swing angle are determined, the second distance between the subsatellite point and the strip center of the observation strip can be calculated based on the near-end spherical distance and the far-end spherical distance, wherein the near-end spherical distance is determined based on the satellite height and the near-end satellite-side swing angle, and the far-end spherical distance is determined based on the satellite height and the far-end satellite-side swing angle.

[0158] After the second distance is determined, the strip center-side swing angle of the target observation satellite subsatellite point to the strip center can be calculated in combination with the satellite height. Meanwhile, after the longitude and latitude of the target observation satellite subsatellite point and the longitude and latitude of the regional center are obtained, the third distance between them can be calculated by the secant formula, and the regional center-side swing angle of the target observation satellite subsatellite point to the regional center can be calculated.

[0159] After the second distance, the third distance, the strip center-side swing angle, and the regional center-side swing angle are determined, the first distance between the regional center and the strip center can be determined based on the size relationship between the strip center-side swing angle and the regional center-side swing angle.

[0160] Optionally, the size relationship between the strip center-side swing angle and the regional center-side swing angle can include: the strip center-side swing angle and the regional center-side swing angle are in the same direction, and the strip center-side swing angle is greater than or equal to the regional center-side swing angle, which indicates that the distance between the strip center and the subsatellite point is greater than the distance between the regional center and the subsatellite point, and the first distance between the strip center and the regional center can be determined by subtracting the third distance from the second distance; the strip center-side swing angle and the regional center-side swing angle are in the same direction, and the strip center-side swing angle is less than the regional center-side swing angle, which indicates that the distance between the strip center and the subsatellite point is less than the distance between the regional center and the subsatellite point, and the first distance between the strip center and the regional center can be determined by subtracting the second distance from the third distance; the strip center-side swing angle and the regional center-side swing angle are in opposite directions, which indicates that the strip center and the regional center are located on both sides of the subsatellite point, and the first distance between the strip center and the regional center can be determined by the sum of the second distance and the third distance.

[0161] For example, continuing with the previous example, this method will be further explained by taking the execution of an observation task targeting a region on the Earth's surface as an example. The calculation methods for the second distance L between the center of the strip and the nadir point, as well as the side swing angle α0 of the strip center, can be found in the previous example and will not be repeated here.

[0162] The lateral swing angle of the region center is α c The latitude and longitude of the nadir point of the target observation satellite are (lon1, lat1), and the latitude and longitude of the center of the region are (lon2, lat2). The difference in latitude and longitude is:

[0163] Δlat=lat2-lat1, Δlon=lon2-lon1

[0164] Based on the difference in latitude and longitude, the core parameter 'a' can be expressed as:

[0165]

[0166] Correspondingly, the third distance d between the center of the region and the sub-satellite point can be expressed as:

[0167]

[0168] The lateral swing angle of the region's center can then be expressed as:

[0169]

[0170] Among them, R e Where is the Earth's radius, and H is the altitude of the target observation satellite.

[0171] Then it can be based on Figure 3 This further explains how the first distance d is determined. Specifically, see [link to documentation]. Figure 3 , Figure 3 This diagram illustrates the positional relationship between the center of a strip, the center of a region, and the sub-star point, according to one embodiment of this specification.

[0172] When the swing angle at the center of the strip and the swing angle at the center of the region are in the same direction, and the swing angle at the center of the strip is greater than or equal to the swing angle at the center of the region, that is:

[0173] α0α c ≥0,|α0|≥|α c |

[0174] At this time, as Figure 3 As shown in Figure a, the first distance D can be represented as:

[0175] D = Ld

[0176] When the swing angle at the center of the strip and the swing angle at the center of the region are in the same direction, and the swing angle at the center of the strip is smaller than the swing angle at the center of the region, that is:

[0177] α0α c ≥0,|α0|<|α c |

[0178] At this time, as Figure 3 As shown in Figure b, the first distance can be expressed as:

[0179] D=dL

[0180] When the swing angle at the center of the strip and the swing angle at the center of the region are opposite, that is:

[0181] α0α c <0

[0182] At this time, as Figure 3 As shown in Figure c, the first distance can be expressed as:

[0183] D = d + L

[0184] In this embodiment, a second distance from the nadir point to the center of the observation strip is calculated based on the near-end spherical distance and the far-end spherical distance. The strip center side-swing angle is calculated based on the second distance and the satellite altitude. Then, a third distance from the region center to the nadir point and the region center side-swing angle are calculated based on the latitude and longitude of the region center and the nadir point. The first distance from the region center to the center of the observation strip is determined based on the relationship between the strip center side-swing angle and the region center side-swing angle. This accurately calculates the relative positional relationship between the target observation area and the observation strip under different positional relationships, providing an accurate geometric basis for subsequent calculation of the observation coverage area based on the first distance, effectively improving the planning accuracy and execution efficiency of satellite observation missions.

[0185] In one optional embodiment of this specification, calculating the observation coverage area of ​​the observation strip over the target observation area based on the first distance, the region radius, and the half-width of the observation strip includes: determining the positional relationship between the observation strip and the target observation area based on the size relationship between the first distance, the region radius, and the half-width of the observation strip; determining the observation coverage area based on the positional relationship between the observation strip and the target observation area; and calculating the observation coverage area of ​​the observation strip over the target observation area based on the observation coverage area and the target observation area.

[0186] The size relationship among the first distance, the region radius and the swath half-width of the observation swath is a basis for judging the relative position relationship between the target observation region and the observation swath, and is used to determine whether the target observation region is completely located in the observation swath, partially located in the observation swath or completely located outside the observation swath. The position relationship between the observation swath and the target observation region is a spatial distribution state obtained based on the numerical comparison of the first distance, the region radius and the swath half-width, and includes three cases of complete coverage, partial coverage and no coverage. For example, when the region radius is 10 kilometers and the swath half-width is 20 kilometers, if the first distance is 5 kilometers, which is less than the difference between the region radius and the swath half-width, it is indicated that the target observation region is completely located in the observation swath; if the first distance is 35 kilometers, which is greater than the sum of the region radius and the swath half-width, it is indicated that the target observation region and the observation swath are completely not overlapped.

[0187] The observation coverage region is a geographical range actually covered by the target observation satellite when the target observation region is observed by the satellite-borne sensor under a specific time window and operation parameter. The shape and area of the observation coverage region depend on the position relationship between the observation swath and the target observation region. In the case of complete coverage, the observation coverage region is equal to the target observation region, that is, the entire circular region; in the case of partial coverage, the observation coverage region is a geometric region of the intersection of the two, that is, a semicircular, circular arc or circular arc trapezoidal region; and in the case of no coverage, the observation coverage region does not exist.

[0188] In the case that the position relationship between the observation swath and the target observation region is determined based on the size relationship among the first distance, the region radius and the swath half-width of the observation swath, the observation coverage region can be further determined, and the observation coverage area can be determined according to the actual shape of the observation coverage region.

[0189] In the embodiments of the present specification, the observation coverage region is determined and the observation coverage area is calculated based on the size relationship among the first distance, the region radius and the swath half-width of the observation swath, so that the quantitative calculation of the coverage effect of the target observation region under different time windows is realized, a data basis for selecting the optimal target time window and target operation parameter is provided, and the maximized coverage of the target observation region is realized in the limited transit time, thereby improving the planning accuracy and execution efficiency of the satellite observation task.

[0190] In an optional embodiment of this specification, the relationship between the first distance, the region radius, and the half-width of the observation strip includes: the first distance being greater than the sum of the region radius and the half-width of the strip; the first distance being less than the difference between the region radius and the half-width of the strip; and the first distance being greater than the difference between the region radius and the half-width of the strip and less than the sum of the region radius and the half-width of the strip. Determining the positional relationship between the observation strip and the target observation region based on the relationship between the first distance, the region radius, and the half-width of the observation strip includes: when the first distance is greater than the sum of the region radius and the half-width of the strip, the target observation region is located outside the observation strip; when the first distance is less than the difference between the region radius and the half-width of the strip, the target observation region is located within the observation strip; and when the first distance is greater than the difference between the region radius and the half-width of the strip and less than the sum of the region radius and the half-width of the strip, the target observation region is partially located within the observation strip.

[0191] In practical applications, the relationship between the first distance, the region radius, and the half-width of the observed strip can include: the first distance is greater than the sum of the region radius and the half-width of the strip; the first distance is less than the difference between the region radius and the half-width of the strip; and the first distance is greater than the difference between the region radius and the half-width of the strip and less than the sum of the region radius and the half-width of the strip.

[0192] Specifically, when the first distance is greater than the sum of the region radius and the half-width of the strip, there is a completely non-overlapping spatial distribution between the target observation region and the observation strip. In this case, the distance from the center of the region to the center of the strip exceeds the coverage boundary of the observation strip, indicating that the entire target observation region is outside the observation strip, and the observation coverage area is zero. This situation typically occurs when the target observation region is too far from the satellite's orbit or when the observation strip width is insufficient, such as when the satellite is at a high altitude and its side-swing angle is limited, preventing the observation strip from covering distant regional targets.

[0193] When the first distance is less than the difference between the region radius and the half-width of the strip, the target observation area is completely contained within the observation strip. In this case, the distance from the center of the region to the center of the strip is less than the inner boundary of the effective coverage area of ​​the observation strip, indicating that the entire target observation area is within the effective range of the observation strip. For example, when the satellite adjusts its observation direction with a large side tilt angle and the radius of the target observation area is small (such as point targets like airports or ports), the observation coverage area equals the total area of ​​the target observation area, and no additional calculation of the intersection area is required.

[0194] In the case that the first distance is between the difference between the radius of the region and the half-width of the strip and the sum of the radius of the region and the half-width of the strip, there is a partial overlap between the target observation region and the observation strip in the spatial distribution. At this time, the distance from the center of the region to the center of the strip is between the edge of the observation strip and the inner boundary, resulting in that part of the target observation region is located in the observation strip and the other part is located outside the observation strip. For example, when the target observation satellite observes a larger region (such as a city or a mountain) at a medium side swing angle, the area of the intersection region needs to be determined through geometric calculation, and the coverage range can be quantified by the area formula of the circular arc or the circular arc trapezoid.

[0195] Optionally, the size relationship between the first distance, the radius of the region and the half-width of the observation strip further includes that the radius of the region is greater than the half-width of the strip, and the first distance is less than the difference between the radius of the region and the half-width of the strip. In this case, it is indicated that the width of the target observation region exceeds the observation strip, and the observation strip passes through the middle of the target observation region, and the observation coverage region is a circular arc trapezoid.

[0196] Optionally, the running parameters can further include the satellite speed, and then based on the satellite speed and the observation coverage region, the visible time window can be calculated after the observation coverage region is determined. Correspondingly, the determination of the visible time window is also different for the positional relationship between the observation strip and the target observation region.

[0197] In the case that the first distance is greater than the sum of the radius of the region and the half-width of the strip, the observation coverage region does not exist, and the visible time window also does not exist, i.e. 0; in the case that the first distance is less than the difference between the radius of the region and the half-width of the strip, the observation coverage region is the target observation region, and the visible time window is equal to the diameter of the target observation region divided by the satellite speed; in the case that the first distance is greater than the difference between the radius of the region and the half-width of the strip and less than the sum of the radius of the region and the half-width of the strip, it needs to be further discussed how to determine the visible time window.

[0198] Optionally, the determination of the visible time window further includes a time margin. Specifically, in the actual execution process of the observation task, there can be a delay in the start and imaging of the satellite-borne sensor of the target observation satellite, and there can be a measurement error in the boundary of the target observation region. Therefore, the visible time window can be appropriately extended by adding a time margin to the visible time window to ensure sufficient observation of the target observation satellite for the target observation region. Generally, the time margin can be set to 1-3 seconds.

[0199] Exemplarily, the above example is used to execute the observation task for the target observation region on the surface of the earth, and the method is further described. Specifically, referring to Figure 4 , Figure 4A schematic diagram of the positional relationship between the target observation area and the observation strip in the case where the first distance is greater than the sum of the radius of the area and the half-width of the strip is shown. As shown in Figure 4 The target observation area is completely located outside the strip boundary of the observation strip, that is:

[0200] D > W + R

[0201] Let the covered area be AcessArea and the uncovered area be SplitArea, then:

[0202] AcessArea = 0, SplitArea = πR 2

[0203] Correspondingly, the visible time window T does not exist.

[0204] Specifically, refer to Figure 5 Figure 5 A schematic diagram of the positional relationship between the target observation area and the observation strip in the case where the first distance is less than the difference between the radius of the area and the half-width of the strip is shown. As shown in Figure 5

[0205] The target observation area is completely located inside the strip boundary of the observation strip, that is:

[0206] D ≤ W - R

[0207] Let the covered area be AcessArea and the uncovered area be SplitArea, then:

[0208] AcessArea = πR 2 , SplitArea = 0

[0209] Correspondingly, the visible time window T is:

[0210]

[0211] Wherein, V is the satellite speed, and Δt is the time margin.

[0212] Specifically, refer to Figure 6 Figure 6 A schematic diagram of the positional relationship between the target observation area and the observation strip in the case where the radius of the area is greater than the half-width of the strip, and the first distance is less than the difference between the radius of the area and the half-width of the strip is shown. As shown in Figure 6

[0213] The width of the target observation area exceeds the observation strip, and the observation strip passes through the middle of the target observation area, that is:

[0214] D ≤ R - W​​​​

[0215] denoted as AcessArea, and SplitArea, then:

[0216]

[0217] AcessArea = πR 2 -SplitArea1-SplitArea2

[0218] Since the center of the circle is located within the observation strip, correspondingly, the visible time window T is:

[0219]

[0220] where V is the satellite speed and Δt is the time margin.

[0221] In the embodiments of the present specification, by comparing the values of the first distance, the area radius and the strip half-width, the spatial distribution state between the target observation area and the observation strip is accurately divided, the quantitative evaluation of the coverage effect under different time windows is realized, the situations of complete coverage, partial coverage or non-coverage are automatically identified, the observation coverage area is determined and the observation coverage area is calculated, without relying on manual experience judgment, so as to quickly select the optimal observation scheme within the limited transit time, provide a data basis for the planning and execution of satellite observation tasks, and improve the observation efficiency and resource utilization rate.

[0222] In an optional embodiment of the present specification, in the case that the first distance is greater than the difference between the area radius and the strip half-width and less than the sum of the area radius and the strip half-width, the target observation area is partially located within the observation strip, comprising: in the case that the first distance is greater than the difference between the area radius and the strip half-width and less than the strip half-width, the center of the area circle is located within the observation strip; in the case that the first distance is greater than the strip half-width and less than the sum of the area radius and the strip half-width, the center of the area circle is located outside the observation strip.

[0223] In actual application, in the case that the first distance is greater than the difference between the area radius and the strip half-width and less than the sum of the area radius and the strip half-width, the target observation area is partially located within the observation strip, at this time, it is necessary to further judge based on the relationship among the first distance, the strip half-width and the area radius.

[0224] Specifically, in the case that the first distance is greater than the difference between the radius of the region and the half-width of the strip and less than the half-width of the strip, it indicates that the distance from the center of the region to the center of the observation strip is less than the half-width of the strip, at this time the center of the region is located inside the observation strip, and the observation strip covers the center of the region and the surrounding part. For example, when the target observation region is a city region with a radius of 10 kilometers, the half-width of the strip is 15 kilometers, and the distance from the center of the region to the center of the strip is 8 kilometers, the center of the region is completely located in the observation strip, and the observation coverage area includes the center of the region and the surrounding region.

[0225] In the case that the first distance is greater than the half-width of the strip but less than the sum of the radius of the region and the half-width of the strip, it indicates that the distance from the center of the region to the center of the observation strip exceeds the half-width of the strip, and the center of the region is located outside the observation strip, and the observation strip only covers the edge part of the target observation region. For example, when the distance from the center of the region to the center of the strip is 16 kilometers and the half-width of the strip is 15 kilometers, the center of the region is located outside the observation strip, and the observation coverage area is only the edge region of the target observation region overlapping with the observation strip.

[0226] Exemplarily, the above example is used to further illustrate the method by taking the target observation region on the surface of the earth as an example.

[0227] Specifically, referring to Figure 7 , Figure 7 a schematic diagram of the positional relationship between the target observation region and the observation strip in the case that the first distance is greater than the difference between the radius of the region and the half-width of the strip and less than the half-width of the strip is shown. As Figure 7 shown.

[0228] The center of the region of the target observation region is located inside the observation strip, and the observation strip covers the center of the region and the surrounding range, that is,

[0229] W-R<D<W

[0230] Let the coverage area be AcessArea and the non-coverage area be SplitArea, then:

[0231]

[0232] AcessArea=πR 2 -SplitArea

[0233] Since the center is located in the observation strip, correspondingly, the visible time window T is:

[0234]

[0235] wherein V is the satellite speed and Δt is the time margin.

[0236] Specifically, referring toFigure 8 , Figure 8 A schematic diagram of the positional relationship between the target observation area and the observation strip in the case where the first distance is greater than the half-width of the strip and less than the sum of the half-width of the strip and the radius of the area is shown. As shown in Figure 8 .

[0237] The area center of the target observation area is located outside the observation strip, and the observation strip only covers the edge part of the target observation area, that is,

[0238] W < D < W + R

[0239] Let the covered area be AcessArea and the uncovered area be SplitArea, then:

[0240]

[0241] AcessArea = πR 2 -SplitArea

[0242] Since the center is located outside the observation strip, the length of the cut chord can be represented as:

[0243]

[0244] Correspondingly, the visible time window T is:

[0245]

[0246] Where V is the satellite speed and Δt is the time margin.

[0247] In the embodiments of the present specification, by further fine judgment based on the position of the area center in the partial coverage scenario, the observation coverage area is calculated in combination with the geometric relationship, the precise evaluation of the coverage effect of different time windows is realized in the actual observation task execution process, especially for the case where the target observation area and the observation strip partially overlap, the precision of the coverage area calculation is improved, thereby optimizing the time window selection strategy and ensuring the maximum observation efficiency of the target area within the limited transit time.

[0248] In an optional embodiment of the present specification, based on the observation coverage areas corresponding to a plurality of time windows, a target time window is determined from the plurality of time windows, and a target running parameter corresponding to the target time window, comprising: determining a target time window from a plurality of time windows based on the observation coverage areas corresponding to the plurality of time windows; determining a target running parameter corresponding to the target time window based on the observation coverage area corresponding to the target time window.

[0249] In the case that the observation coverage areas corresponding to the plurality of time windows are determined, the target time window can be determined based on the size relationship of the observation coverage areas, and the target operation parameter can be determined based on the observation coverage area.

[0250] Specifically, when the target observation area has the maximum observation coverage area in a certain time window, the time window is the target time window, and the operation parameter (such as the subsatellite point, the satellite side swing angle, the satellite height, etc.) corresponding to the target time window is the target operation parameter.

[0251] Optionally, if the observation coverage areas of a plurality of time windows are the same, the target time window and the target operation parameter corresponding to the target time window need to be further screened in combination with the feasibility of the operation parameter (such as whether the side swing angle exceeds the physical limit of the sensor) or the task priority (such as preferentially selecting a time window in which the satellite load is low).

[0252] Taking an actual scenario as an example, assuming that the target observation area is a certain city (the regional center latitude and longitude is 116.4°E, 39.9°N, and the radius is 10 kilometers), and the satellite passes through the area in three time windows with different operation parameters (subsatellite point, satellite side swing angle, and satellite height). The observation coverage area of each time window is calculated as follows:

[0253] Time window A: the observation coverage area is 80% of the area, and the satellite side swing angle is 15°;

[0254] Time window B: the observation coverage area is 95% of the area, and the satellite side swing angle is 25°;

[0255] Time window C: the observation coverage area is 70% of the area, and the satellite side swing angle is 35°.

[0256] In this case, time window B is selected as the target time window, and the satellite side swing angle 25° corresponding to time window B is the target operation parameter.

[0257] Optionally, the target operation parameter corresponding to the target time window is determined based on the observation coverage area corresponding to the target time window, including: calculating the imaging side swing angle of the target observation satellite based on the observation coverage area corresponding to the target time window, and determining the target operation parameter corresponding to the target time window based on the imaging side swing angle.

[0258] In the embodiments of the present specification, the target time window and the target operation parameter corresponding to the target time window are screened by quantitatively comparing the observation coverage areas of the time windows and combining the feasibility of the operation parameter, so that the target area can be maximally covered in the limited transit time, and the satellite operation strategy is dynamically optimized based on the actual observation data, thereby reducing the dependence on manual experience and improving the automation level and execution efficiency of the task planning.

[0259] In an optional embodiment of the present specification, the running parameters include the sub-satellite point and the satellite side swing angle, and the target running parameter includes the imaging side swing angle; the target time window is determined from the plurality of time windows based on the observation coverage areas corresponding to the plurality of time windows, including: determining the time window with the largest observation coverage area as the target time window from the plurality of time windows based on the observation coverage areas corresponding to the plurality of time windows; determining the target running parameter corresponding to the target time window based on the observation coverage area corresponding to the target time window, including: calculating the imaging side swing angle according to the observation coverage area corresponding to the target time window, the sub-satellite point and the satellite side swing angle; determining the target running parameter corresponding to the target time window based on the imaging side swing angle.

[0260] The imaging side swing angle is the lateral deviation angle of the satellite-borne sensor relative to the satellite orbit direction during the observation process of the target observation satellite in a specific time window, which is used to adjust the direction and width of the observation strip to maximize the coverage of the target observation area. Specifically, the imaging side swing angle can be calculated by the intersection of the region side swing angle (i.e. the lateral deviation angle from the sub-satellite point to the edge of the target observation area) of the edge of the target observation area and the satellite side swing angle (the observation strip boundary angle determined by the satellite running parameters), to ensure that the observation strip formed by the actual observation imaging angle can cover the data collection of the target observation area, and avoid collecting the observation strip that does not cover the target observation area. For example, when the region side swing angles of the two side edges of the target observation area are 15° and 30° respectively, and the satellite side swing angle range is 20° to 35°, the imaging side swing angle can be determined as 25° to 30° to reduce the invalid data collection of 30° to 35°, thereby saving the collection resources.

[0261] Specifically, in the case of determining the observation coverage areas corresponding to the plurality of time windows, the observation coverage area corresponding to each time window can be calculated and compared to select the time window with the largest observation coverage area as the target time window.

[0262] The calculation of the observation coverage area is based on the geometric relationship between the first distance from the region center of the target observation area to the center of the observation strip, the region radius and the strip half-width, for example, when the first distance is less than the difference between the region radius and the strip half-width, the coverage area is equal to the total area of the target region; when the first distance is between the two, the coverage area is the area of the intersection region.

[0263] In the case of determining the target time window, the imaging side swing angle can be calculated based on the satellite side swing angle and the subsatellite point included in the running parameter corresponding to the target time window, and the observation coverage area. Specifically, the determination of the imaging side swing angle needs to combine the intersection of the regional side swing angle of the target observation area and the satellite side swing angle. For example, the direct intersection of the regional side swing angle and the satellite side swing angle can be determined: the intersection of the satellite side swing angle determined by the regional side swing angle range at both ends of the target observation area and the near-end satellite side swing angle and the far-end satellite side swing angle is calculated to determine the angle range of the imaging side swing angle.

[0264] Optionally, in the case of determining the imaging side swing angle, the imaging side swing angle can be dynamically adjusted based on the observation coverage area. The imaging side swing angle can be further constrained based on physical limitations and task priorities.

[0265] In the embodiments of the present specification, the target time window is determined from multiple time windows based on quantitative comparison of the observation coverage area, and the imaging side swing angle is calculated in combination with the regional side swing angle and the satellite side swing angle, which dynamically optimizes the running parameter within the limited transit time of the target observation satellite, maximizes the coverage of the target area, avoids relying on artificial experience judgment, improves the automation level and execution efficiency of the satellite observation task, and at the same time, through geometric calculation and parameter screening, ensures the efficient use of imaging observation resources and reduces the collection of invalid observation data.

[0266] In an optional embodiment of the present specification, the imaging side swing angle is calculated according to the observation coverage area, the subsatellite point and the satellite side swing angle corresponding to the target time window, comprising: determining the regional side swing angle of the target observation area according to the observation coverage area and the subsatellite point corresponding to the target time window; and taking the intersection of the satellite side swing angle and the regional side swing angle as the imaging side swing angle.

[0267] The regional side swing angle of the observation coverage area is the range of the lateral offset angle of the edge of the target observation area relative to the satellite orbit direction under the target time window. Specifically, the regional side swing angle includes the near-end regional side swing angle and the far-end regional side swing angle.

[0268] The near-end regional side swing angle is the lateral offset angle of the side closer to the subsatellite point of the target observation satellite in the edge of the target observation area, which is used to describe the relative position relationship between the near-end boundary of the target area and the satellite orbit direction.

[0269] The far-end regional side swing angle is the lateral offset angle of the side farther away from the subsatellite point of the target observation satellite in the edge of the target observation area, which is used to describe the relative position relationship between the far-end boundary of the target area and the satellite orbit direction.

[0270] Specifically, the region side swing angle can be calculated by the region center coordinate of the target observation region, the region radius, and the geometric characteristics of the observation strip (such as the strip center and the strip half-width), in combination with the subsatellite point coordinate and the satellite side swing angle, to determine the effective range of the imaging side swing angle. For example, when the target observation region is a city with a radius of 10 kilometers, the satellite side swing angle range is 20° to 35°, and the near-end region side swing angle is 15° and the far-end region side swing angle is 30°, the imaging side swing angle needs to be limited to 20° to 30° to ensure coverage and avoid invalid imaging.

[0271] After the region center and the region radius of the target observation region are determined, the near-end region and the far-end region can be further determined, wherein the near-end region is closer to the subsatellite point, and the far-end region is farther from the subsatellite point.

[0272] After the near-end region and the far-end region are determined, the spherical distance between the near-end region and the far-end region of the target observation region and the subsatellite point can be calculated by using the formula of the secant, and the near-end region side swing angle and the far-end region side swing angle of the target observation satellite from the subsatellite point to the near-end region and the far-end region can be further calculated in combination with the earth radius and the satellite altitude.

[0273] After the near-end region side swing angle and the far-end region side swing angle are determined, the angle range of the region side swing angle can be determined according to the near-end region side swing angle and the far-end region side swing angle. In combination with the near-end satellite side swing angle and the far-end satellite side swing angle, the angle range of the satellite side swing angle can be determined. The angle range of the imaging side swing angle can be determined by taking the intersection of the angle range of the satellite side swing angle and the angle range of the region side swing angle.

[0274] Optionally, the determination of the near-end region side swing angle and the far-end region side swing angle needs to be combined with whether the near-end region and the far-end region of the target observation region are on the same side or on the opposite side of the subsatellite point, that is, whether the near-end region side swing angle and the far-end region side swing angle are in the same direction or in the opposite direction.

[0275] Exemplarily, the above example is used to perform an observation task for a target observation region on the surface of the earth, and the method is further described.

[0276] Specifically, referring to Figure 9 , Figure 9 a determination position relationship diagram of an imaging side swing angle provided by one embodiment of the present specification is shown. As Figure 9 shown.

[0277] The region center of the target observation region is located within the observation strip, and the region far-end and the region near-end of the target observation region are located on both sides of the subsatellite point. The far-end satellite side swing angle a fmax is between the strip boundary of the far-end and the subsatellite point, and the near-end satellite side swing angle afmin The lateral swing angle α between the far end of the region and the sub-satellite point is the lateral swing angle of the near end region. c2 The lateral swing angle α between the far end of the region and the sub-satellite point is the lateral swing angle of the far end region. c1 The observation coverage area is determined by the angle range of the intersection of the satellite side-swing angle and the regional side-swing angle.

[0278] Correspondingly, the lateral swing angle α in the proximal region is calculated. c2 and distal region lateral sway angle α c1 See also Figure 10 , Figure 10 This diagram illustrates the positional relationship between the proximal and distal region side swing angles according to an embodiment of this specification. Figure 10 As shown.

[0279] See Figure 10 Figure a shows the calculation of the lateral tilt angle α of the nadir point relative to the far end of the region. c1 , can be represented as:

[0280]

[0281] That is:

[0282]

[0283] Among them, R e Where θ is the Earth's radius, H is the satellite altitude of the target observation satellite, and θ1 is the central angle corresponding to the far end of the region.

[0284] See Figure 10 In Figure b, if the proximal end of the region is on the same side as the distal end of the region, that is:

[0285] d≥R

[0286] Then calculate the near-end region lateral swing angle α of the sub-satellite point relative to the near end of the region. c2 , can be represented as:

[0287]

[0288] α c2 =sign(α) c1 )×|α c2 |

[0289] Among them, R e Where θ is the Earth's radius, H is the satellite altitude of the target observation satellite, and θ2 is the central angle corresponding to the near end of the region.

[0290] See Figure 10 In diagram c, if the proximal and distal ends of the region are on opposite sides, that is:

[0291] d <R

[0292] Then, a near-end region side swing angle a of the star-down point to the near end of the region is calculated c2 , which can be expressed as:

[0293]

[0294] a c2 = -sign(a c1 ) x |a c2 |

[0295] wherein R e is the radius of the earth, H is the satellite height of the target observation satellite, and θ1 is the central angle corresponding to the far end of the region.

[0296] Then, the imaging side swing angle a c is calculated correspondingly, and the determination of the imaging side swing angle a c can be expressed as:

[0297] [a cmin , a cmax ] = [min(a c1 , a c2 ), max(a c1 , a c2 )]

[0298] The angle range of the imaging side swing angle is:

[0299]

[0300] That is, the imaging side swing angle can be expressed as:

[0301]

[0302] In the embodiments of the present specification, the imaging side swing angle is calculated by combining the intersection of the region side swing angle of the observation coverage area and the satellite side swing angle, the precise coverage control of the target observation region is realized, the selection range of the satellite side swing angle is dynamically optimized, the effectiveness of the observation data and the resource utilization rate are improved, the boundary conditions of the region side swing angle are quantified through geometric relations, the dependence on artificial experience is reduced, and the automation level and the execution efficiency of the satellite task planning are improved.

[0303] In an optional embodiment of the present specification, the running parameters corresponding to the plurality of time windows include single-side swing observation; determining the observation strip of the target observation satellite in the plurality of time windows based on the running parameters corresponding to the plurality of time windows includes: determining the single-side swing observation strip of the target observation satellite in the plurality of time windows based on the running parameters corresponding to the plurality of time windows; determining the observation coverage area corresponding to the plurality of time windows based on the observation strip in the plurality of time windows and the position information of the target observation area includes: determining the single-side swing observation coverage area corresponding to the plurality of time windows based on the single-side swing observation strip in the plurality of time windows and the position information of the target observation area.

[0304] Single-side swing observation is a running mode in which the target observation satellite only observes the target observation area in a single direction through a single-beam satellite-borne sensor during orbit operation. Specifically, in the case of single-beam satellite-borne sensor observation, the satellite side swing angle is only deflected to one side (such as the left side or the right side) to form a single-side swing observation strip.

[0305] Single-side swing observation strip is the observation range formed on the ground by the satellite-borne sensor of the target observation satellite in the single-side swing observation mode. Its geometric characteristics are that the strip center line deviates from the subsatellite point to one side, and the strip width is determined by the side swing angle in a single direction.

[0306] Single-side swing observation coverage area is the target area actually covered by the target observation satellite when observing the target observation area through the satellite-borne sensor in the single-side swing observation mode. Its size is determined by the relative position relationship between the single-side swing observation strip and the target area, which may be complete coverage, partial coverage or no coverage.

[0307] In the single-side swing observation mode of the target observation satellite using a single-beam satellite-borne sensor, the running parameters of the target observation satellite only include the side swing angle of a single observation strip. Correspondingly, the determination of the observation strip can calculate the spherical distance on the corresponding side according to the satellite altitude of the target observation satellite and the satellite side swing angle of the single-side swing, and determine the distance from the strip center to the subsatellite point and the strip half-width in combination with the spherical distance and the subsatellite point coordinates, and further determine the single-side swing observation strip based on the strip center and the half-width.

[0308] In the process of calculating the single-side swing observation coverage area, the distance from the region center of the target area to the center of the single-side swing observation strip can be determined, and the geometric relationship between the region radius and the strip half-width is determined.

[0309] Exemplarily, the above example is used to perform an observation task for a target observation area on the surface of the earth, which is further described. Specifically, referring to Figure 11 , Figure 11A schematic diagram of a single-side swing observation position relationship provided by an embodiment of the present specification is shown. As shown in Figure 11

[0310] The single-side swing observation strip formed by the single-side swing observation can be A+B or C+D, and is distributed on one side of the subsatellite point. If A+B is used as the single-side swing observation strip, the single-side swing observation coverage area formed is AcessArea1 and AcessArea2, and the corresponding uncovered area is SplitArea1; if C+D is used as the single-side swing observation strip, the single-side swing observation coverage area formed is AcessArea1, and the corresponding uncovered area is SplitArea1 and SplitArea2.

[0311] In an embodiment of the present specification, by using the single-side swing observation mode, the target observation satellite can dynamically adjust the satellite swing angle for the observation requirement in a specific direction under limited maneuvering capability, thereby reducing unnecessary two-way adjustment resource consumption, improving observation efficiency, the geometric characteristics of the single-side swing observation strip simplify the calculation logic of the strip half-width and center, reduce the complexity of the observation coverage area, and optimize the utilization rate of imaging resources.

[0312] In an optional embodiment of the present specification, the running parameters corresponding to the plurality of time windows include double-side swing observation; based on the running parameters corresponding to the plurality of time windows, the observation strip of the target observation satellite in the plurality of time windows is determined, including: based on the running parameters corresponding to the plurality of time windows, the double-side swing observation strip of the target observation satellite in the plurality of time windows is determined; based on the observation strip in the plurality of time windows and the position information of the target observation area, the observation coverage area corresponding to the plurality of time windows is determined, including: based on the double-side swing observation strip in the plurality of time windows and the position information of the target observation area, the double-side swing observation coverage area corresponding to the plurality of time windows is determined.

[0313] The double-side swing observation is a running mode in which the target observation satellite simultaneously observes the target observation area to both sides of the satellite orbit direction through the double-beam satellite-borne sensor during orbit operation. Specifically, the double-side swing observation mode is applicable to a scenario in which the coverage range of a single observation needs to be expanded, for example, rapid scanning of a large-area target by a SAR satellite.

[0314] Specifically, under the observation determination of the double-beam satellite-borne sensor, the swing angle of the satellite includes two observation strips symmetrically or asymmetrically distributed on both sides of the subsatellite point, and the data is collected by the left and right satellite-borne sensors at the same time, thereby realizing the bidirectional coverage of the target observation area.

[0315] ​The double-side-swing observation strip is an observation range formed by a satellite-borne sensor on the ground in a double-side-swing observation mode of a target observation satellite. Its geometric characteristics are that two observation strips are distributed on both sides of a subsatellite point, and the width of each strip is determined by the satellite side-swing angle on the corresponding side.

[0316] The double-side-swing observation coverage area is an actual target area covered by a target observation satellite when the target observation satellite performs observation on a target observation area by using a satellite-borne sensor in a double-side-swing observation mode. Its size is determined by the relative position relationship between the double-side-swing observation strip and the target area, and it can be completely covered, partially covered, or not covered.

[0317] In a double-side-swing observation mode of a target observation satellite using a double-beam satellite-borne sensor, the operating parameters of the target observation satellite include the side-swing angles of the two-side observation strips. Correspondingly, the determination of the observation strips can be performed according to the satellite altitude and the satellite side-swing angle of any side swing to calculate the spherical distance on the corresponding side, and then the distance from the strip center to the subsatellite point and the half-width of the observation strip are determined based on the spherical distance and the subsatellite point coordinates, and finally the double-side-swing observation strip is determined based on the strip center and the half.

[0318] In the process of calculating the double-side-swing observation coverage area, the distance from the center of the target area to the center of any strip in the double-side-swing observation strip can be determined, and the geometric relationship between the area radius and the strip half-width is determined.

[0319] Exemplarily, the above example is used as an example to perform an observation task on the target observation area on the earth's surface, and the method is further described. Specifically, referring to Figure 12 , Figure 12 A schematic diagram of the position relationship of the double-side-swing observation is shown in an embodiment of the present specification. As Figure 12 shown.

[0320] The double-side-swing observation strip formed by the double-side-swing observation is B+C, which is distributed on both sides of the subsatellite point and is symmetrical. The double-side-swing observation coverage area formed is AcessArea1 and AcessArea2, and the corresponding uncovered area is SplitArea2.

[0321] Alternatively, for a target observation satellite that can perform both single-side-swing observation and double-side-swing observation, that is, as Figure 12 shown, the single-side-swing observation strip formed by the single-side-swing observation can be A+B or C+D, and the double-side-swing observation strip formed by the double-side-swing observation is B+C. Then the single-side-swing observation coverage area corresponding to the observation strip A+B can be recorded as S1, the single-side-swing observation coverage area corresponding to the observation strip C+D can be recorded as S4, the observation coverage area of the observation strip B can be calculated as S2, and the observation coverage area of the observation strip C can be calculated as S3. Then it can be further judged that:

[0322] If S1>0 and S4=0, it is right single side swing observation; if S1=0 and S4>0, it is left single side swing observation; if S1=0 and S4=0, it indicates that the target observation area is invisible; if S1>0 and S4>0, the sizes of S1, S2+S3 and S4 are compared, and the maximum value is the maximum area of the region coverage. If S1>S2+S3 or S4>S2+S3, single side swing observation is adopted; if S2+S3>S1 and S2+S3>S4, double side swing observation is adopted.

[0323] In the embodiments of the present specification, by adopting the double side swing observation mode, the target observation satellite can cover the range of both sides of the subsatellite point in a single transit, improve the observation efficiency, reduce the number of repeated observations in multiple transits, reduce the task execution cost, and accurately evaluate the coverage effect under different time windows by combining the spherical distance and geometric relationship to calculate the double side swing observation coverage area, thereby providing a scientific basis for dynamically adjusting the satellite side swing angle, so as to realize efficient coverage of a large range of target areas in a limited transit time, and optimize the utilization of satellite resources.

[0324] Corresponding to the above method embodiments, the present specification also provides an embodiment of a target observation task execution method. Referring to Figure 13 , Figure 13 A flowchart of a target observation task execution method according to an embodiment of the present specification is shown, which specifically includes the following steps.

[0325] Step 1302: Obtain a target time window and a target running parameter, wherein the target time window is determined based on the satellite-based target time window and target running parameter determination method as described above;

[0326] Step 1304: Schedule the target observation satellite to observe the target observation area and collect observation data in the target time window using the target running parameter to obtain target observation data.

[0327] In the embodiments of the present specification, by determining the target time window and the target running parameter based on the above method, accurate coverage control and efficient resource utilization of the target observation area are realized, the optimal execution scheme is automatically selected by quantitatively comparing the observation coverage areas under different time windows, the redundant cost of repeated observation in multiple transits is reduced by combining the dynamic adjustment logic of the imaging side swing angle, the automation level and execution efficiency of the satellite observation task are significantly improved, and the effectiveness and integrity of the observation data are ensured.

[0328] Corresponding to the above method embodiments, the present specification also provides a satellite system embodiment, Figure 14 A structural schematic diagram of a satellite system according to an embodiment of the present specification is shown. As shown in Figure 14As shown, the satellite system 1400 includes a target observation satellite 1402 and a satellite control module 1404; the satellite control module 1404 is configured to control the target observation satellite 1402 by performing the method as described above.

[0329] The satellite system refers to a complete observation system composed of a target observation satellite and a satellite control module, which is used for observing and collecting data of a target area on the surface of the earth or other celestial bodies.

[0330] The target observation satellite is a satellite used for observing and collecting data of a specific target observation area. The target observation satellite can carry on-board sensors to observe the target observation area to be observed in a specific target time window with target operation parameters during the operation around a specific celestial body (such as the earth, the moon, etc.). Specifically, the target observation satellite can be an agile satellite or a synthetic aperture satellite in a single-satellite observation scenario, and can change the observation strip by adjusting the satellite roll angle and determining the sub-satellite point position with different operation orbits.

[0331] The satellite control module is a module in the satellite system responsible for controlling the operation parameters of the satellite, including real-time adjustment and control of the satellite roll angle, orbit position, operation speed and other parameters, to ensure that the target observation satellite can perform the observation task according to the preset operation parameters.

[0332] The above is a schematic scheme of a satellite system of the embodiment. It should be noted that the technical scheme of the satellite system belongs to the same concept as the technical scheme of the above-mentioned target time window and target operation parameter determination method based on a satellite. The details of the technical scheme of the satellite system that are not described in detail can be referred to the description of the technical scheme of the above-mentioned target time window and target operation parameter determination method based on a satellite.

[0333] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than those shown in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired results. In some embodiments, multitasking and parallel processing are possible or may be advantageous. It should be noted that, for the foregoing method embodiments, for the sake of simplicity, they are all described as a series of actions; however, those skilled in the art should understand that the embodiments of this specification are not limited to the described order of actions, because according to the embodiments of this specification, some steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the embodiments of this specification. In the above embodiments, the descriptions of each embodiment have different focuses; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0334] The preferred embodiments disclosed above are merely illustrative of this specification. Optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the embodiments described herein. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the embodiments, thereby enabling those skilled in the art to better understand and utilize this specification. This specification is limited only by the claims and their full scope and equivalents.

Claims

1. A satellite-based target time window and target operating parameter determination method, characterized in that, The method comprises: acquiring running parameters of a target observation satellite observing a target observation area and collecting observation data in a plurality of time windows, wherein the target observation satellite adopts different running parameters to pass through the target observation area in the plurality of time windows; determining observation strips of the target observation satellite in the plurality of time windows based on the running parameters corresponding to the plurality of time windows; determining observation coverage areas corresponding to the plurality of time windows based on the observation strips in the plurality of time windows and position information of the target observation area; determining a target time window from the plurality of time windows and a target running parameter corresponding to the target time window based on the observation coverage areas corresponding to the plurality of time windows.

2. The method of claim 1, wherein, The running parameters comprise a subsatellite point and a satellite roll angle. The method further comprises: determining the observation strips of the target observation satellite in the plurality of time windows based on the subsatellite points and the satellite roll angles corresponding to the plurality of time windows.

3. The method of claim 2, wherein, The running parameters further comprise a satellite altitude, and the satellite roll angle comprises a near-end satellite roll angle and a far-end satellite roll angle. The method further comprises: determining near-end spherical distances corresponding to the plurality of time windows based on the satellite altitude and the near-end satellite roll angles corresponding to the plurality of time windows, and determining far-end spherical distances corresponding to the plurality of time windows based on the satellite altitude and the far-end satellite roll angles corresponding to the plurality of time windows; determining strip half-widths corresponding to the plurality of time windows based on angular directivities between the near-end satellite roll angles corresponding to the plurality of time windows and the far-end satellite roll angles corresponding to the plurality of time windows, and the near-end spherical distances corresponding to the plurality of time windows and the far-end spherical distances corresponding to the plurality of time windows; determining strip centers corresponding to the plurality of time windows based on the strip half-widths corresponding to the plurality of time windows; determining the observation strips of the target observation satellite in the plurality of time windows based on the strip half-widths corresponding to the plurality of time windows and the strip centers corresponding to the plurality of time windows.

4. The method of claim 3, wherein, The method further comprises: in a case where the angular directivities between the near-end satellite roll angles corresponding to the plurality of time windows and the far-end satellite roll angles corresponding to the plurality of time windows are in the same direction, determining the strip half-widths corresponding to the plurality of time windows based on differences between the near-end spherical distances corresponding to the plurality of time windows and the far-end spherical distances corresponding to the plurality of time windows. In a case that an angular directionality between the near-end satellite side-slip angle corresponding to the multiple time windows and the far-end satellite side-slip angle corresponding to the multiple time windows is opposite, a sum of the near-end spherical distance corresponding to the multiple time windows and the far-end spherical distance corresponding to the multiple time windows is used to determine a strip half-width corresponding to the multiple time windows.

5. The method of claim 1, wherein, The operation parameters include a subsatellite point and a satellite side-slip angle, the position information of the target observation area includes an area center and an area radius of the target observation area, and the observation strip includes a strip center and a strip half-width; The determination of the observation coverage area corresponding to the multiple time windows based on the observation strips in the multiple time windows and the position information of the target observation area includes: determining a first distance between the area center and the strip center of the observation strip in the multiple time windows; calculating the observation coverage area of the observation strip on the target observation area according to the first distance, the area radius, and the strip half-width of the observation strip.

6. The method of claim 5, wherein, The operation parameters further include a satellite altitude, and the satellite side-slip angle includes a near-end satellite side-slip angle and a far-end satellite side-slip angle; Before the determination of the first distance between the area center and the strip center of the observation strip in the multiple time windows, the method further includes: calculating a second distance between the subsatellite point and the strip center of the observation strip based on a near-end spherical distance and a far-end spherical distance, wherein the near-end spherical distance is determined based on the satellite altitude and the near-end satellite side-slip angle, and the far-end spherical distance is determined based on the satellite altitude and the far-end satellite side-slip angle; calculating a strip center side-slip angle based on the second distance and the satellite altitude; The determination of the first distance between the area center and the strip center of the observation strip in the multiple time windows includes: calculating a third distance between the area center and the subsatellite point based on the longitude and latitude of the area center and the longitude and latitude of the subsatellite point, and an area center side-slip angle between the target observation satellite and the area center; determining the first distance between the area center and the strip center of the observation strip in the multiple time windows according to a size relationship between the strip center side-slip angle and the area center side-slip angle.

7. The method of claim 5, wherein, The calculation of the observation coverage area of the observation strip on the target observation area according to the first distance, the area radius, and the strip half-width of the observation strip includes: determining a position relationship between the observation strip and the target observation area according to a size relationship between the first distance, the area radius, and the strip half-width of the observation strip; determining an observation coverage area according to the position relationship between the observation strip and the target observation area; calculating the observation coverage area of the observation strip on the target observation area based on the observation coverage area and the target observation area.

8. The method of claim 7, wherein, The size relationship between the first distance, the area radius and the strip half-width of the observation strip comprises: the first distance is greater than the sum of the area radius and the strip half-width, the first distance is less than the difference between the area radius and the strip half-width, the first distance is greater than the difference between the area radius and the strip half-width and less than the sum of the area radius and the strip half-width; The position relationship between the observation strip and the target observation area is determined according to the size relationship between the first distance, the area radius and the strip half-width of the observation strip, comprising: In the case that the first distance is greater than the sum of the area radius and the strip half-width, the target observation area is located outside the observation strip; In the case that the first distance is less than the difference between the area radius and the strip half-width, the target observation area is located inside the observation strip; In the case that the first distance is greater than the difference between the area radius and the strip half-width and less than the sum of the area radius and the strip half-width, the target observation area is partially located inside the observation strip.

9. The method of claim 8, wherein, The target observation area is partially located inside the observation strip in the case that the first distance is greater than the difference between the area radius and the strip half-width and less than the sum of the area radius and the strip half-width, comprising: In the case that the first distance is greater than the difference between the area radius and the strip half-width and less than the strip half-width, the area center is located inside the observation strip; In the case that the first distance is greater than the strip half-width and less than the sum of the area radius and the strip half-width, the area center is located outside the observation strip.

10. The method of claim 1, wherein, The target time window is determined from the plurality of time windows based on the observation coverage areas corresponding to the plurality of time windows, and the target running parameter corresponding to the target time window, comprising: The target time window is determined from the plurality of time windows based on the observation coverage areas corresponding to the plurality of time windows; The target running parameter corresponding to the target time window is determined based on the observation coverage area corresponding to the target time window.

11. The method of claim 10, wherein, The running parameter comprises a subsatellite point and a satellite roll angle, and the target running parameter comprises an imaging roll angle; The target time window is determined from the plurality of time windows based on the observation coverage areas corresponding to the plurality of time windows, comprising: The time window with the largest observation coverage area is determined as the target time window from the plurality of time windows based on the observation coverage areas corresponding to the plurality of time windows; The target running parameter corresponding to the target time window is determined based on the observation coverage area corresponding to the target time window, comprising: The imaging roll angle is calculated according to the observation coverage area corresponding to the target time window, the subsatellite point and the satellite roll angle; The target running parameter corresponding to the target time window is determined based on the imaging roll angle.

12. The method of claim 11, wherein, The imaging roll angle is calculated according to the observation coverage area corresponding to the target time window, the subsatellite point and the satellite roll angle, comprising: determining a region side swing angle of the target observation region according to the observation coverage area corresponding to the target time window and the subspace point; taking an intersection of the satellite side swing angle and the region side swing angle as an imaging side swing angle.

13. The method according to any one of claims 1 to 12, characterized in that, The operation parameters corresponding to the multiple time windows include single side swing observation; The method further includes: determining single side swing observation strips of the target observation satellite in the multiple time windows according to the operation parameters corresponding to the multiple time windows; The method further includes: determining single side swing observation coverage areas corresponding to the multiple time windows according to the single side swing observation strips in the multiple time windows and the position information of the target observation region.

14. The method according to any one of claims 1 to 12, characterized in that, The operation parameters corresponding to the multiple time windows include double side swing observation; The method further includes: determining double side swing observation strips of the target observation satellite in the multiple time windows according to the operation parameters corresponding to the multiple time windows; The method further includes: determining double side swing observation coverage areas corresponding to the multiple time windows according to the double side swing observation strips in the multiple time windows and the position information of the target observation region.

15. A method of performing a target observation mission, the method comprising: receiving a target observation mission request; determining a target observation mission plan; and executing the target observation mission plan. The method further includes: acquiring a target time window and a target operation parameter, wherein the target time window is determined based on the satellite-based target time window and target operation parameter determination method in claims 1-14; scheduling a target observation satellite to observe a target observation region and collect observation data in the target time window using the target operation parameter to obtain target observation data.

16. A satellite system, characterized by The method further includes: a satellite control module; The satellite control module is configured to perform the method in any one of claims 1-15 to control the target observation satellite.

Images