A fast on-board online window prediction method for remote sensing payloads with heterogeneous shapes

Abstract

The present invention discloses a method for rapid prediction of online windows of remote sensing payloads of heterogeneous shapes, and the method comprises the following steps: step S1: orbit division; orbit extrapolation from six satellite numbers to obtain continuous orbit prediction; the entire orbit is divided into multiple orbits according to the orbital period of the satellite, and then each orbit is discretized into independent points in time sequence and the time corresponding to each orbit point is recorded to screen the orbit on the same side; step S2: determining the time step for rough search; step S3: determining the rough visible time window; step S4: binary search for the precise visible time window; by calculating whether the intermediate moment is visible to the ground point target, the precise visible time window is further determined, and the satellite observes the ground target point. The technology can accurately calculate the visible time window, and realize the online rapid calculation of the satellite window for dynamic tasks.

Description

Technical Field

[0001] The invention relates to the field of satellite control technology, in particular to an on-board online window rapid prediction method for heterogeneous shape remote sensing payloads. Background Art

[0002] Satellite swarm is a satellite group working mode that imitates biological swarms such as bee swarms, bird flocks and fish schools in nature, achieves complementary capabilities between satellites through information sharing and coordinated actions, and realizes complex group behaviors as a whole through simple behaviors of individuals in the swarm. Swarming behavior is a common phenomenon in nature. Typical examples include flocks of birds migrating in formation, schools of fish swimming in groups, ant colonies working in collaboration, bacterial communities living in clusters, etc. The common feature of these phenomena is that a certain number of autonomous individuals present orderly coordinated movements and behaviors at the collective level through mutual cooperation and self-organization. With the vigorous development of satellite technology, the mature application of multi-satellite technology with one rocket, and the rise of commercial aerospace companies, the cost of satellite development, launch and deployment has been further reduced. The comprehensive application of multiple satellites and multiple sensors has gradually become the mainstream trend of satellite applications, and satellite cluster self-synchronization operation and maintenance technology has become one of the research hotspots in the aerospace field. Among them, efficient cluster inter-satellite task allocation, determination of accurate visible time windows, and design of efficient multi-satellite and multi-earth observation task execution plans are key technologies for efficient self-synchronization and collaboration of satellite clusters.

[0003] The existing technology has the following difficulties: 1. The on-board computing resources are in short supply, and an efficient and accurate on-board observation window calculation algorithm with low computational effort is required. 2. The satellite field of view has different shapes (conical, rectangular, and other special shapes), and the target types are diverse (point targets, regional targets). It is necessary to establish a visibility judgment model for different types of targets in fields of view of different shapes. Summary of the invention

[0004] In response to the problems existing in the prior art, the present invention proposes a satellite cluster observation method based on regional dynamic decomposition, which can accurately calculate the visible time window, proposes a window calculation method for maximizing regional target coverage considering satellite attitude maneuvers, and proposes a "global coarse search + local fine search" on-board window rapid calculation method, which realizes the online rapid calculation of satellite windows for dynamic tasks.

[0005] Specifically, the present invention provides a method for rapid prediction of online windows of remote sensing payloads of heterogeneous shapes on board, which is realized by calculating the satellite observation window of an imaging satellite (electronic satellite, optical satellite, SAR satellite) for a point target. The method comprises the following steps:

[0006] Step S1: orbit division; take the six satellite numbers at the time of initiation of the forecast mission as the starting point to perform orbit extrapolation, calculate the continuous position and velocity sequence of the satellite in the future, that is, continuous orbit forecast; divide the entire orbit into multiple orbits according to the satellite operation cycle, then discretize each orbit into independent points in time sequence and record the time corresponding to each orbit point, retrieve all discrete points, retain the part on the same side of the earth as the ground target point, and perform same-side orbit screening;

[0007] Step S2: determine the time step for coarse search;

[0008] Step S3: Determine the rough visible time window; according to the heterogeneous shapes of the observation fields of different imaging satellites (electronic satellites, optical satellites, SAR satellites), establish different satellite and ground target visibility judgment criteria to support visibility judgment; when the ground target is a point target, calculate each discrete time point Whether the point target is visible and the side swing angle of the satellite observing the ground; visible, If it is not visible, the start time of the visible window is determined to be at and between; when visible, When it is not visible, the end time of the visible window is at and between;

[0009] Step S4: Binary search for the exact visible time window; by calculating the intermediate time Whether the ground point target is visible, the precise visible time window is further determined, and the satellite observes the ground target point; the precisely determined time window is combined with the corresponding roll angle and output, and a prediction table of the time and roll angle that the satellite will experience in the future after the mission is initiated is obtained to achieve rapid prediction of the remote sensing satellite's earth observation window.

[0010] Furthermore, in step S1, when the start and end time of the observation mission after the forecast mission initiation time is known, the period of the satellite orbiting the earth can be recursively obtained by considering the orbital dynamics equation of J2 perturbation. The entire orbit is divided into multiple orbits according to the satellite operation period, and then each orbit is discretized into independent points in time sequence and the time corresponding to each orbit point is recorded. , =1, 2, ...; same-side track screening, screening out track points with longitudes exceeding ±90° of the target.

[0011] Furthermore, in step S2, when determining the time step, for a circular field of view or a rectangular field of view, the maximum step length of movement can only be the case where two adjacent fields of view are just tangent to each other.

[0012] Furthermore, in step S3, a visibility calculation model of satellite sensors to point targets is established for the heterogeneous shapes of the observation fields of different imaging satellites (electronic satellites, optical satellites, SAR satellites), and a rough visible time window is determined. The specific implementation method is: for the detailed imaging observation problem of imaging satellites to point targets, a visibility calculation model of rectangular field of view sensors to point targets considering attitude maneuvers is established.

[0013] Further, in step S4, the binary search for the precise visible time window is as follows: the start time interval of the visible window during the rough search is , calculate the intermediate time Is the ground point target visible? If visible, the starting interval is , if not visible, then ; Repeat the above steps until the entire interval size , is the custom error size, that is, the magnitude of the error; the middle moment of the last interval is the precise start time of the visible window. Similarly, the end time of the visible window is obtained. The time and side swing angle that can be experienced in the future to implement the observation mission of the ground target are integrated into a prediction table to obtain a rapid forecast result.

[0014] On the other hand, a method for rapid prediction of online windows of remote sensing payloads with heterogeneous shapes is provided, the method comprising the following steps:

[0015] Step S1: orbit division; take the six satellite numbers at the time of initiation of the forecast mission as the starting point to perform orbit extrapolation, calculate the continuous position and velocity sequence of the satellite in the future, that is, continuous orbit forecast; divide the entire orbit into multiple orbits according to the satellite operation cycle, and then discretize each orbit into independent points in time sequence and record the time corresponding to each orbit point to screen the orbit on the same side;

[0016] Step S2: determine the time step for coarse search;

[0017] Step S3: Determine the roughly visible time window; when the ground target is a regional target, the discrete sampling points of the regional target contour are recorded as , =1, 2, ..., s, calculate the satellite at each discrete time point For each discrete sampling point The visible time window of the area is obtained; the earliest visible time and the latest invisible time of the area are obtained, that is, the rough visible time window of the area :

[0018] in, Indicates the start time of the visible window. Indicates The visible window start time of the sampling point, Indicates the end time of the visible window. Indicates The visible window end time of the sampling point;

[0019] Step S4: Binary search for the precise visible time window; by calculating whether the intermediate time is visible to the ground area target, the precise visible time window is further determined, and the satellite observes the ground target area.

[0020] Further, in step S4, for the ground area target, the first point seen is used and a rough start time and the latest invisible point and approximate end time , find the point Exact start time With point Exact end time , for the interval Further screening; traverse each time point in the interval and calculate all sampling points in the area The visibility of the satellite at that point in time and the coverage are calculated , if and only if hour, , It is a custom constant, indicating that the time point is visible to the area. After the traversal is completed, the discrete time points visible to the area are taken as the union to obtain the final accurate visible time window of the ground area target.

[0021] The present invention can accurately calculate the visible time window, proposes a window calculation method for maximizing regional target coverage considering satellite attitude maneuvers, and proposes a "global coarse search + local fine search" on-board window rapid calculation method, thus realizing the online rapid calculation of satellite windows for dynamic tasks. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The flowchart of the architecture of the on-board online window rapid prediction method for heterogeneous shape remote sensing payloads according to the present invention is shown;

[0023] Figure 2 A schematic diagram of a rectangular field of view used in the on-board online window rapid prediction method for remote sensing payloads of heterogeneous shapes according to the present invention is shown;

[0024] Figure 3 A schematic diagram of a conical field of view used in the on-board online window rapid prediction method for heterogeneous shape remote sensing payloads according to the present invention is shown. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The following is combined with Figure 1-Figure 3 The specific embodiments of the present invention are described in detail. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0029] The present invention provides an on-board online window rapid prediction method for remote sensing payloads of heterogeneous shapes. The technical key points are an on-board rapid calculation algorithm for the optimal visible time window based on regional dynamic decomposition, a method for rapid on-board calculation of the visible window of a regional target by a satellite sensor, screening out the satellite orbit on the same side according to the target position, reducing the amount of calculation, and adopting a large step length coarse search and a binary search fine search method to improve the calculation efficiency, thereby realizing the observation of high-value targets on the ground by a cluster of earth observation satellites.

[0030] The satellite observation system includes a ground station system, relay command satellites, and electronic satellites, optical imaging satellites, and SAR imaging satellite clusters. Among them, the ground station system is mainly used to implement cluster task injection and receive satellite cluster earth observation results. The relay command satellite is mainly used to receive cluster tasks injected from the ground and command the cluster to autonomously negotiate task allocation. Electronic satellites, optical imaging satellites, and SAR imaging satellites form a cluster of three satellites, and multiple clusters of satellites form an earth observation satellite cluster.

[0031] The observation process is as follows: First, the ground station notifies the relay command satellite of the target information of the area of ​​interest to the user. Secondly, the relay command satellite initiates a cluster bidding with all electronic satellites, and selects the electronic satellite with the best timeliness and energy consumption as the mission execution satellite through the local mission planning bidding results of each electronic satellite. Then, after the electronic satellite finds a high-value target in the process of searching the target area, it sends the target's accurate location and electromagnetic characteristics information to the relay satellite. Subsequently, the relay satellite initiates a cluster bidding to all optical and SAR imaging satellites, and selects the imaging satellite with the best timeliness and energy consumption as the mission execution satellite through the local mission planning bidding results of each electronic satellite. Finally, after imaging the target in detail, the imaging satellite transmits the data to the ground station, completing the autonomous closed loop of target discovery, judgment, and imaging in orbit.

[0032] like Figure 1 As shown, the on-board online window rapid prediction method for heterogeneous shape remote sensing payloads according to the present invention is universal for "earth observation satellites" (including electronic satellites, optical satellites, SAR satellites, etc.), and includes the following steps:

[0033] Step S1: Orbit division. When the start and end time of the observation mission are known, since the period of the satellite orbiting the earth is fixed, the orbit is extrapolated starting from the six satellite numbers at the time of the forecast mission initiation, and the continuous position and velocity sequence of the satellite in the future is calculated to achieve continuous orbit prediction; the entire orbit is divided into multiple orbits according to the satellite operation cycle, and then each orbit is discretized into independent points in time sequence and the time corresponding to each orbit point is recorded. , =1, 2, .... Same-side track screening. The longitude of the actual given target (mainly referring to the regional target) will not exceed plus or minus 90°, based on which half of the track points can be directly screened out.

[0034] Step S2: Determine the time step for coarse search. Although choosing a large step size can improve computational efficiency, it is not necessarily the case that the larger the step size, the better. Too large a step size may lead to missed targets. Therefore, for circular and rectangular fields of view, the maximum step size of the movement can only be taken when two adjacent fields of view are just tangent. Sample the target. The regional target contour is sampled according to the longitude and latitude to facilitate visibility judgment and coverage calculation. For point targets, no sampling is required.

[0035] Step S3: Determine the rough visible time window. According to the heterogeneous shapes of the observation fields of different imaging satellites (electronic satellites, optical satellites, SAR satellites), different satellite and ground target visibility judgment criteria are established to support visibility judgment; for point targets, calculate each discrete time point Whether the point target is visible and the side swing angle of the satellite observing the ground, the visibility calculation model is as follows. It can be seen that If it is not visible, the start time of the visible window is at and between; if visible, When it is not visible, the end time of the visible window is at and For regional targets, the discrete sampling points of the regional target contour are recorded as , =1, 2, ..., s, calculate the satellite at each discrete time point For each discrete sampling point If for each If there is no time window during the observation period, it means that the satellite is invisible to the area during the entire observation period. On the contrary, there is a visible time window. Similar to the case of point targets, each sampling point will have its own visible window start time and visible window end time, from which the earliest visible time and the latest invisible time of the area can be obtained, that is, the rough regional visible time window :

[0036] (1)

[0037] (2)

[0038] in, Indicates the start time of the visible window. Indicates The visible window start time of the sampling point, Indicates the end time of the visible window. Indicates The visible window end time of the sample points.

[0039] Step S4: Binary search for the exact visible time window. The approximate start and end time of the visible time window has been obtained in step S3. Due to the large step search, there is a certain error between this time window and the actual time window, so a more detailed search is needed to find the actual time window. For point targets, assume that the start time interval of the visible window during the large step search is , calculate the intermediate time Is the ground point target visible? If visible, the starting interval is , if not visible, then ; Repeat the above steps until the entire interval size , is the custom error size, that is, the magnitude of the error; the middle moment of the last interval is the precise start time of the visible window, and the idea of ​​finding the precise end time is the same as above.

[0040] In summary, the accurate visible time window of the ground target point has been obtained. For ground area targets, since the area contour has been discretized into points, and the first point seen has been found in step 3 and a rough start time and the latest invisible point and approximate end time , using the above method to find the precise window of the point target, we can find the point Exact start time With point Exact end time , but the interval It is not the visible time window of the ground area, because the visibility of some sampling points in the ground area does not mean that the area is visible, so it is also necessary to Further screening. Traverse each time point in the interval and calculate all sampling points in the area The visibility of the satellite at that point in time and the coverage are calculated , if and only if hour, , is a custom constant, indicating that the time point is visible to the region. After the traversal is completed, the discrete time points visible to the region are taken as the union, and the final accurate visible time window of the ground area target can be obtained. The accurately determined time window is combined with the corresponding roll angle and output, and the time and roll angle prediction table that the satellite will experience in the future after the forecast mission is initiated to implement the observation mission of the ground target is obtained, so as to realize the rapid prediction of the remote sensing satellite's earth observation window.

[0041] Specifically, in step S3, a visibility calculation model of a satellite sensor to a point target is established to determine a rough visible time window. The specific implementation method is to establish a visibility calculation model of a rectangular field of view sensor to a point target considering attitude maneuvers for a detailed imaging observation problem of an imaging satellite to a point target; the method includes the following steps:

[0042] S3.1 Establish a model for calculating the visibility of point targets by using a rectangular field of view sensor with attitude maneuvers. In the point target observation task, the projection of the satellite remote sensor’s field of view directly onto the ground is a rectangle, which is determined by the vertical half angle of the satellite’s rectangular field of view. and horizontal half angle The only certainty is Figure 2 As shown, the coordinate system is the satellite orbit coordinate system, the origin It represents the location of the satellite, with the z-axis pointing to the center of the earth, and the y-axis being obtained by the product of the z-axis direction vector and the satellite velocity direction. Finally, the x-axis direction is determined according to the right-hand screw theorem to establish a rectangular coordinate system centered on the satellite.

[0043] S3.2 In order to better describe the positional relationship between the satellite and the ground point, it is necessary to introduce the Earth Centered Inertial (ECI) coordinate system. The origin of the ECI coordinate system is at the center of the earth, O e The basic plane is the J2000 Earth equatorial plane, the x-axis points from the center of the earth to the J2000 vernal equinox, the z-axis points from the center of the earth to the North Pole along the Earth's rotation axis, and the y-axis is perpendicular to the x and z axes and is determined by the right-hand rule.

[0044] S3.3. After the coordinate system is determined, mathematical modeling and solving are used to further calculate whether the ground target is within the visible range of the satellite. Let the satellite be S, the target point be T, and the center of the earth be O. Considering the J2 perturbation force, the six elements of the satellite orbit can be converted to the satellite velocity and position. That is, the six elements of the satellite orbit can be input to output the position vector and velocity vector of the satellite at any time. For the optical satellite and SAR satellite designed for service, the heterogeneous shape of the field of view is a rectangle. Let the satellite S coordinate be , the target point T coordinate is , the vertical half-angle limit of the field of view is , the horizontal half-angle limit is , based on the above parameters, a mathematical model can be established to determine whether the current satellite is visible to ground targets. Among them, the J2 perturbation force is the non-central gravity caused by the Earth's flattening on the satellite. The J2 perturbation force causes the satellite orbit to deviate from the standard Kepler elliptical orbit (the position velocity deviates from the standard Kepler orbit and gradually diverges). Since the mission planning window prediction time can reach several days, the orbit deviation caused by the J2 perturbation is significant, and the J2 perturbation must be considered in the orbit prediction. Figure 2As shown, the x-axis is the direction of satellite motion. Based on the coordinates of the satellite and the target point, the vector pointing from the satellite to the target point can be obtained.

[0045] (3)

[0046] Will Projected onto the ozy surface in the satellite orbit coordinate system, we get , projected onto the ozx surface, we get ,Depend on , and The corresponding horizontal deflection angle can be obtained and vertical deflection , by judging Is it in between, Is it in It can be determined whether the target is within the field of view. and The calculation method is as follows:

[0047] (4)

[0048] (5)

[0049] in, is the unit vector of the x-axis of the satellite orbit coordinate system, is the unit vector of the y-axis of the satellite orbit coordinate system, is the unit vector of the z-axis of the satellite orbit coordinate system. Satellites generally have a side swing function, which can expand their observation range by side swinging, such as Figure 1 As shown, the satellite field of view will rotate about the x-axis in the yoz plane, which will introduce a roll angle , then the condition for the target to be visible is changed to Is it in between, Is it in between.

[0050] On the other hand, by establishing a visibility calculation model for regional targets of satellite sensors, a rough visible time window is determined. The specific implementation method is to solve the problem of large-scale scanning of regional targets by electronic satellites. Its field of view heterogeneous shape is a conical field of view. Considering the cumulative coverage and visibility calculation model of the conical field of view sensor with attitude maneuvering for regional targets. It includes the following steps:

[0051] S301. Establish a calculation model for the coverage and visibility of regional targets by satellite sensors taking into account attitude maneuvers. In the task of observing regional targets, the projection of the satellite remote sensor's observation field of view directly on the ground is a circle, and the visible range of the field of view is a cone. Given a half angle of the field of view The field of view can be determined, such as Figure 3 As shown in the figure, the coordinate system still uses the satellite orbit coordinate system and the ECI coordinate system.

[0052] S302. Define the regional target to be observed as a regional polygon composed of multiple line segments, which is a closed convex set, and the longitude and latitude coordinates of the endpoints of each line segment are given in clockwise or counterclockwise order. Since the time window calculation for regional targets is greatly restricted by the shape of the region, it is difficult to directly give a general regional target visibility judgment method from a geometric perspective. Inspired by the observation of point targets, the method of dot sampling is considered to convert the regional problem into a point problem. The method adopted is to sample the entire regional contour in units of longitude and latitude, and then determine whether each sampling point is within the field of view. However, there is no clear quantitative relationship between the sampling point and the target area, that is, how many sampling points are visible to be considered as the region visible. In order to solve this problem, the concept of coverage is introduced, that is, the ratio of visible sampling points to all sampling points in the regional contour. When the coverage reaches the set threshold, it means that the region is visible and the coverage is also an evaluation criterion for measuring the accuracy of visible window calculation.

[0053] S303. Conical field of view is better than rectangular field of view in judging whether the sampling point is visible. It only needs to compare the angle between the target point with the satellite as the vertex and the center of the field of view and the half angle of the field of view to determine whether it is in the field of view. However, when the side swing occurs, the visibility judgment will change, such as Figure 3 The specific calculation method is as follows

[0054] (6)

[0055] (7)

[0056] in, is the center vector of the field of view, is the side swing angle, is the angle between the satellite field of view center vector and the satellite target vector, is the satellite-to-target connection vector. The electronic satellite and the point target are visible when the half angle of the electronic satellite conical field of view is not exceeded. This visibility model is used to determine the visibility of the target by the satellite sensor at any time during the window calculation period, and is the basis for the satellite to point target window calculation.

[0057] The technical effects of the present invention are as follows: at the cluster level, the autonomous on-orbit allocation of satellite cluster tasks is realized through the event-triggered double-layer contract network mechanism. At the single-satellite level, the autonomous dynamic readjustment of satellite earth observation tasks is realized through the minimum conflict set progressive modification of the single-satellite dynamic task planning method. The on-orbit autonomous closed loop of the discovery, judgment, and imaging of high-value targets on the ground by the earth observation satellite cluster is realized.

[0058] 1. An event-triggered dual-layer contract network satellite cluster task autonomous allocation mechanism is proposed. Through the dual-layer contract network mechanism, the electronic satellite cluster can autonomously search for high-value ground targets and the imaging satellite cluster can autonomously and detailedly image high-value ground targets, thus realizing an autonomous closed loop of ground target discovery, judgment, and detailed imaging in orbit.

[0059] 2. A single-satellite dynamic mission planning method considering the solar altitude angle was proposed, which realized the online dynamic readjustment of the satellite mission plan and achieved the dynamic real-time response of the satellite Earth observation mission in orbit.

[0060] 3. A window calculation method for maximizing regional target coverage considering satellite attitude maneuvers was proposed, and a fast on-board window calculation method of "global coarse search + local fine search" was proposed, realizing online fast calculation of satellite windows for dynamic tasks.

[0061] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, those skilled in the art can combine or combine different embodiments or examples described in this specification and the features therein without causing any contradiction.

[0062] Although the above content has shown and described the embodiments of the present invention, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace, modify and other update operations on the above embodiments within the scope of the present invention.

Claims

1. A method for rapid prediction of online windows of remote sensing payloads with heterogeneous shapes, characterized in that: The method comprises the following steps: Step S1: orbit division; take the six satellite numbers at the time of initiation of the forecast mission as the starting point to perform orbit extrapolation, calculate the continuous position and velocity sequence of the satellite in the future, and realize continuous orbit forecast; divide the entire orbit into multiple orbits according to the satellite operation cycle, and then discretize each orbit into independent points in time sequence and record the time corresponding to each orbit point, retrieve all discrete points, retain the part on the same side of the earth as the ground target point, and perform same-side orbit screening; Step S2: determine the time step for coarse search; Step S3: Determine the rough visible time window; according to the heterogeneous shapes of the observation fields of different imaging satellites, establish different satellite and ground target visibility judgment criteria to support visibility judgment; the different imaging satellites include electronic satellites, optical satellites and SAR satellites; when the ground target is a point target, calculate each discrete time point Whether the point target is visible and the side swing angle of the satellite observing the ground; visible, If it is not visible, the start time of the visible window is determined to be at and between; when visible, When it is not visible, the end time of the visible window is at and between; Step S4: Binary search for the exact visible time window; by calculating the intermediate time Whether the ground point target is visible, the precise visible time window is further determined, and the satellite observes the ground target point; the precisely determined time window is combined with the corresponding roll angle and output, and a prediction table of the time and roll angle that the satellite will experience in the future after the mission is initiated is obtained to achieve rapid prediction of the remote sensing satellite's earth observation window.

2. The method for rapid prediction of online windows of remote sensing payloads with heterogeneous shapes on board satellites according to claim 1 is characterized in that: In step S1, when the start and end time of the observation mission after the forecast mission initiation time is known, the period of the satellite orbiting the earth is recursively obtained by considering the orbital dynamics equation of J2 perturbation. The entire orbit is divided into multiple orbits according to the satellite operation period, and then each orbit is discretized into independent points in time sequence and the time corresponding to each orbit point is recorded. , =1, 2, ...; same side track screening; Screen out orbital points whose longitude exceeds the target by plus or minus 90°.

3. The method for rapid prediction of online windows of heterogeneous-shaped remote sensing payloads on board according to claim 1 is characterized in that: In step S2, when determining the time step, for a circular field of view or a rectangular field of view, the maximum step length of movement can only be the case where two adjacent fields of view are just tangent to each other.

4. The method for rapid prediction of online windows of remote sensing payloads with heterogeneous shapes on board satellites according to claim 1 is characterized in that: In step S3, a visibility calculation model of satellite sensors to point targets is established to determine a rough visible time window. The specific implementation method is to establish a visibility calculation model of point targets by rectangular field of view sensors taking into account attitude maneuvers in response to the detailed imaging observation problem of imaging satellites to point targets.

5. The method for rapid prediction of online windows of remote sensing payloads with heterogeneous shapes on board satellites according to claim 1 is characterized in that: In step S4, the binary search for the precise visible time window is as follows: the start time interval of the visible window during the rough search is , calculate the intermediate time Is the ground point target visible? If visible, the starting interval is , if not visible, then ; Repeat the above steps until the entire interval size , is the custom error size, that is, the magnitude of the error; the middle moment of the last interval is the precise start time of the visible window.

6. A method for rapid prediction of online windows of remote sensing payloads with heterogeneous shapes, characterized in that: The method comprises the following steps: Step S1: orbit division; take the six satellite numbers at the time of initiation of the forecast mission as the starting point to perform orbit extrapolation, calculate the continuous position and velocity sequence of the satellite in the future, and realize continuous orbit prediction; divide the entire orbit into multiple orbits according to the satellite operation cycle, and then discretize each orbit into independent points in time sequence and record the time corresponding to each orbit point to screen the orbit on the same side; Step S2: determine the time step for coarse search; Step S3: Determine the roughly visible time window; when the ground target is a regional target, the discrete sampling points of the regional target contour are recorded as , =1, 2, ..., s, calculate the satellite at each discrete time point For each discrete sampling point The visible time window of the area is obtained; the earliest visible time and the latest invisible time of the area are obtained, that is, the rough visible time window of the area : in, Indicates the start time of the visible window. Indicates The visible window start time of the sampling point, Indicates the end time of the visible window. Indicates The visible window end time of the sampling point; Step S4: Binary search for the precise visible time window; by calculating whether the intermediate time is visible to the ground area target, the precise visible time window is further determined, and the satellite observes the ground target area.

7. The method for rapid prediction of online windows of heterogeneous-shaped remote sensing payloads on board satellite according to claim 6, characterized in that: In step S1, when the start and end time of the observation mission are known, the period of the satellite orbiting the earth is fixed. The entire orbit is divided into multiple orbits according to the satellite operation period, and then each orbit is discretized into independent points in time sequence and the time corresponding to each orbit point is recorded. , =1, 2, ...; same side track screening; Screen out orbital points whose longitude exceeds the target by plus or minus 90°.

8. The method for rapid prediction of online windows of remote sensing payloads with heterogeneous shapes according to claim 6 is characterized in that: In step S2, when determining the time step, for a circular field of view or a rectangular field of view, the maximum step length of movement can only be the case where two adjacent fields of view are just tangent to each other.

9. The method for rapid prediction of online windows of remote sensing payloads with heterogeneous shapes according to claim 6 is characterized in that: In step S3, a rough visible time window is determined by establishing a visibility calculation model of satellite sensors for regional targets. The specific implementation method is to establish a cumulative coverage and visibility calculation model of a conical field of view sensor for regional targets taking into account attitude maneuvers in order to solve the problem of large-scale scanning of regional targets by electronic satellites.

10. The method for rapid prediction of online windows of heterogeneous-shaped remote sensing payloads on board satellite according to claim 6, characterized in that: In step S4, for ground area targets, the first point seen is used and a rough start time and the latest invisible point and approximate end time , find the point Exact start time With point Exact end time , for the interval Further screening; traverse each time point in the interval and calculate all sampling points in the area The visibility of the satellite at that point in time and the coverage are calculated , if and only if hour, , It is a custom constant, indicating that the time point is visible to the area. After the traversal is completed, the discrete time points visible to the area are taken as the union to obtain the final accurate visible time window of the ground area target.

Images