Controlled drift method, device and electronic equipment for regression orbit

Abstract

The present invention provides a controlled drift method, device and electronic device for a regression orbit, wherein the method comprises: determining a nominal regression orbit, including determining the height of the regression orbit and the inclination of the regression orbit; determining a task flow, wherein the task flow comprises a plurality of tasks; parameter calculation: calculating the height difference and inclination difference between the target orbit and the regression orbit according to the sub-satellite point drift of the current task; orbit adjustment: adjusting the satellite orbit according to the height difference and inclination difference between the target orbit and the regression orbit, so that the satellite operates on the target orbit; when executing the next task, performing parameter calculation and orbit adjustment again. The present invention dynamically adjusts the satellite orbit according to the task requirements of different remote sensing tasks in the task flow, realizes the orbit performance optimization of the task flow, and meets the application requirements of multiple tasks and multiple payloads.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of spacecraft orbit control, and in particular to a controlled drift method, device and electronic equipment of a regression orbit. Background Art

[0002] Different mission requirements determine that satellites operate on different orbits. Among them, the regression orbit is an artificial satellite orbit in which the sub-satellite trajectory of the satellite after a period of operation coincides with the original sub-satellite trajectory, that is, the sub-satellite point trajectory periodically overlaps, and the period of overlap is called the regression period.

[0003] There are some shortcomings in the application of conventional regression orbit to earth remote sensing:

[0004] 1. Task-oriented, not task-process-oriented. The regression orbit design is designed for multiple task objectives and multiple task stages. When multiple tasks are not executed simultaneously, such as when there is a progressive relationship between the tasks, the orbital performance cannot be optimized for the task process because its orbital parameters are not optimized and changed according to the task process. For example, a large number of quantitative remote sensing satellites in orbit need to frequently revisit a ground calibration site to achieve rapid calibration. During the observation process, it is necessary to improve the coverage capability and observation quality. The requirements at different stages are completely different, but the conventional orbit operation plan does not adjust or change the orbit according to the requirements.

[0005] 2. Narrow scope of application. The regression orbit has many design constraints. Due to the strict constraint of subsatellite point trajectory overlap, the revisit period and subsatellite point interval design options of the revisit orbit within a certain orbital altitude range are discrete, which limits its application to observation tasks with different widths and observation angles. At certain orbital altitudes, the regression orbit is not suitable for spacecraft with smaller widths to achieve global coverage revisit tasks, and its scope of application is limited.

[0006] 3. Poor observation quality. The regression orbit is used in earth remote sensing missions. There are surface areas far away from the adjacent sub-satellite point trajectory. When the satellite observes this area, since it never passes the sub-satellite point, the observation angle and observation effect will always be relatively poor. This problem is more significant in the regression low-Earth orbit.

[0007] 4. Low coverage efficiency. For Earth remote sensing missions with multiple payloads and different widths, the traditional regression orbit design is difficult to achieve efficient global coverage with multiple widths. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a controlled drift method, device and electronic equipment for a regression orbit to solve the problem of orbit performance optimization in the regression orbit related task process.

[0009] In a first aspect, the present invention provides a controlled drift method of a regression orbit, comprising: determining a nominal regression orbit, including determining the height of the regression orbit and the inclination of the regression orbit; determining a task flow, wherein the task flow includes multiple tasks; parameter calculation: calculating the height difference and inclination difference between a target orbit and the regression orbit according to the sub-satellite point drift of the current task; wherein the sub-satellite point drift is the distance of the corresponding sub-satellite point drift after a regression cycle, and the target orbit is the working orbit after the satellite orbit is adjusted; orbit adjustment: adjusting the satellite orbit according to the height difference and inclination difference between the target orbit and the regression orbit, so that the satellite operates on the target orbit; when executing the next task, performing the parameter calculation and the orbit adjustment again.

[0010] Optionally, if multiple payloads are used simultaneously in a certain mission, then after adjusting the satellite orbit, the method further includes: adjusting the true anomaly angle of the target orbit according to the true anomaly angle change required for the target orbit, so that the sub-satellite point trajectory after a regression cycle has a certain sub-satellite point distance change in the latitude direction relative to the sub-satellite point trajectory before adjusting the true anomaly angle.

[0011] Optionally, the change in the sub-satellite point distance satisfies the following condition: after one regression cycle, the change distances of two adjacent sub-satellite point tracks in the same longitude direction enable the surface coverage strips of the corresponding load to be seamlessly spliced ​​in latitude.

[0012] Optionally, the method further includes: calculating a phase control period of the target orbit, wherein the phase control period is equal to the time required for a corresponding payload that satisfies the sub-satellite point drift to cover a specified latitude area once.

[0013] Optionally, the method further comprises: performing phase control on the multi-payload satellite on the target orbit at fixed time intervals, with the true anomaly angle change being the same each time, wherein the fixed time interval is equal to the phase control period.

[0014] Optionally, calculating the height difference and inclination difference between the target orbit and the regression orbit includes: calculating the height difference between the target orbit and the regression orbit, the height of the target orbit is higher than the regression orbit or the height of the target orbit is lower than the regression orbit.

[0015] Optionally, determining the height of the regression orbit includes: calculating a first orbital height set that meets the requirements of payload imaging performance; calculating a second orbital height set based on orbital life, orbit maintenance frequency and propellant consumption constraints of orbital dynamics; calculating a third orbital height set based on space environment characteristics and protection requirements; and selecting an optimal orbital height according to mission requirements, wherein the optimal orbital height belongs to the intersection of the first orbital height set, the second orbital height set and the third orbital height set.

[0016] Optionally, determining the inclination of the regression orbit includes: confirming the maximum value in the latitude band range that needs to be covered in the earth observation mission, and calculating a first orbital inclination set that meets the specified latitude band coverage in combination with the maximum platform side swing angle allowed by the payload during the observation process; calculating a second orbital inclination set that meets the satellite-to-ground data transmission requirements based on the latitude altitude and position of the available ground stations and the minimum altitude angle constraint of the satellite-to-ground link; determining a third orbital inclination set that can complete the calibration as required based on the design distribution of the calibration field and the observation angle range requirements of the payload on the calibration field; selecting the optimal orbital inclination according to the mission requirements, wherein the optimal orbital inclination belongs to the intersection of the first orbital inclination set, the second orbital inclination set and the third orbital inclination set.

[0017] Optionally, in selecting the optimal orbital height according to mission requirements and / or selecting the optimal orbital inclination according to mission requirements, the optimal orbital height and / or the optimal orbital inclination satisfies at least one of the following conditions: the target orbit can access the data transmission station; the target orbit can observe all calibration sites within the specified observation angle constraint; the target orbit is an orbit with the smallest regression day among the orbits that meet the constraints and have regression characteristics.

[0018] Optionally, the regression orbit is a sun-synchronous orbit.

[0019] Optionally, the target orbit satisfies the characteristics of a sun-synchronous orbit.

[0020] Optionally, the task includes: achieving global coverage of a single payload within the entire latitude range of the southernmost and northernmost latitudes after completing payload calibration; the sub-satellite point drift satisfies the following conditions: after a regression cycle, the change distance of two adjacent sub-satellite point trajectories in the same longitude direction makes the surface coverage strip of the corresponding payload seamlessly spliced ​​in latitude.

[0021] Optionally, the task includes: achieving full coverage of the southern latitude area or full coverage of the northern latitude area after completing the payload calibration; the sub-satellite point drift satisfies the following conditions: after one of the regression cycles, the change distance of the sub-satellite point trajectory in the same longitude direction for two adjacent times makes the surface coverage strip of the southern latitude area or the northern latitude area of ​​the corresponding payload seamlessly spliced ​​in latitude.

[0022] In a second aspect, the present invention provides a controlled drift device for a regression orbit, comprising: a first determination module, used to determine a nominal regression orbit, including determining the height of the regression orbit and the inclination of the regression orbit; a second determination module, used to determine a task flow; wherein the task flow includes multiple tasks; a calculation module, used to calculate the height difference and inclination difference between a target orbit and the regression orbit according to the sub-satellite point drift of the current task; wherein the sub-satellite point drift is the distance of the corresponding sub-satellite point drift after a regression cycle, and the target orbit is the working orbit after the satellite orbit is adjusted; an adjustment module, used to adjust the satellite orbit according to the height difference and inclination difference between the target orbit and the regression orbit, so that the satellite runs on the target orbit; a continue execution module, used to run the calculation module and the adjustment module again when executing the next task.

[0023] In a third aspect, the present invention provides an electronic device comprising: a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the controlled drift method of the regression orbit as described in the first aspect are implemented.

[0024] In a fourth aspect, the present invention provides a readable storage medium storing a program or instruction. When the program or instruction is executed by a processor, the steps of the controlled drift method of the regression orbit as described in the first aspect are implemented.

[0025] Compared with the prior art, the present invention has the following advantages: in the regression orbit related tasks, according to the task requirements of different remote sensing tasks in the mission process, the satellite orbit is dynamically adjusted to realize the sub-satellite point trajectory drift, and the orbit performance of the mission process is optimized to meet the application requirements of multiple tasks and multiple payloads. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0027] Figure 1 It is a schematic flow chart of a controlled drift method of a regression track in one embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of the calibration field position corresponding to a sub-satellite point of the regression orbit in one embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of the coverage range of a certain payload performing a global remote sensing coverage task after calibration in one embodiment of the present invention;

[0030] Figure 4 is a schematic diagram of the effect of sub-satellite point trajectory deviation after the satellite orbit altitude is lowered in one embodiment of the present invention;

[0031] Figure 5 It is a schematic diagram of the coverage effect of payloads with different widths after the satellite changes its orbital altitude in one embodiment of the present invention;

[0032] Figure 6 It is a schematic diagram of the coverage effect of payloads with different widths after the satellite is phase adjusted in one embodiment of the present invention;

[0033] Figure 7 It is a schematic diagram of the trajectory of the sub-satellite point in northern China after the controlled drift quasi-regression orbit is readjusted in one embodiment of the present invention;

[0034] Figure 8 It is a schematic diagram of the sub-satellite point trajectory in the equatorial region after the controlled drift quasi-regression orbit is readjusted in one embodiment of the present invention;

[0035] Fig. 9 It is a schematic diagram of the structure of a controlled drift device for a regression track in one embodiment of the present invention;

[0036] Fig.10 It is a structural schematic diagram of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0038] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0039] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0040] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0041] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0042] The controlled drift approximate regression orbit (quasi-regression orbit) is a series of orbit types derived from the strict sub-satellite point trajectory regression orbit. The sub-satellite point motion trajectory of the satellite is actually a synthesis of the earth's rotation, orbital plane precession and satellite motion. When the satellite passes the equator twice in a row, the longitude difference Δλ between the adjacent trajectories on the equator is:

[0043]

[0044] Among them, ω e is the angular velocity of the Earth's rotation, is the rate of change of right ascension of the orbital ascending node, T Ω It is the time difference between two times when the spacecraft passes through the equatorial plane in the same direction (ascending / descending). The regression orbit is defined as:

[0045] R·Δλ=N·2π

[0046] Where R is the number of orbits required for regression, N is the number of regression days, and the orbit that satisfies this equation is the regression orbit.

[0047] Quasi-regression orbits are generated by adjusting the specified regression orbits. The sub-satellite point drift of the quasi-regression orbit is defined as the difference in sub-satellite point longitude between the ascending / descending intersection of the sub-satellite point trajectory of the Mth orbit and the M+Rth orbit. The sub-satellite point trajectory of this orbit does not strictly repeat the sub-satellite point trajectory of the previous cycle and is not a strict regression orbit. The drift can be adapted to each special mission requirement to achieve efficient observation and coverage.

[0048] Embodiment 1

[0049] Figure 1 is a flow chart of a controlled drift method for a regression track in an embodiment of the present invention, with reference to Figure 1 , the method 100 comprises:

[0050] S110. Determine a nominal regression orbit, including determining a height of the regression orbit and an inclination of the regression orbit.

[0051] In this embodiment, the controlled drift of the satellite is based on the regression orbit, that is, in this embodiment, the satellite (or payload) is fine-tuned based on the regression orbit, which not only meets the mission process requirements, but also has some characteristics of the regression orbit. Of course, strictly speaking, the satellite orbit after adjustment is not a regression orbit, but the adjusted orbit is a fine-tuning based on the regression orbit. In this embodiment, this working orbit is tentatively called a quasi-regression orbit.

[0052] In some implementations, the height of the regression orbit can be calculated in the following manner: calculate the first orbital height set (the set can be understood as a range) that meets the requirements of payload imaging performance, calculate the second orbital height set based on orbital dynamics, orbital maintenance frequency, and propellant consumption constraints, calculate the third orbital height set based on space environment characteristics and protection requirements, and then select the optimal orbital height according to mission requirements, where the optimal orbital height belongs to the intersection of the first orbital height set, the second orbital height set, and the third orbital height set. For example, calculate the orbital height set H1 that meets the requirements of payload imaging performance, calculate the orbital height set H2 based on orbital dynamics, orbital maintenance frequency, and propellant consumption constraints, calculate the orbital height set H3 based on space environment characteristics and protection requirements, and calculate the orbital height set H that meets the common requirements of the above three steps based on the above orbital height constraint analysis, then set H is the intersection of sets H1, H2, and H3.

[0053] In some implementations, if the range of the track height set is small enough, a traversal method can be used to find the optimal solution.

[0054] In some implementations, the regression orbit may be a sun-synchronous orbit. For example, depending on the type of earth remote sensing payload, it is determined whether there is a strong constraint on the solar illumination angle. If there is such a constraint, the orbital inclination should be designed as a sun-synchronous orbit according to the orbital altitude. When the descending node of the sun-synchronous orbit is determined according to the solar illumination angle β, the orbital inclination corresponds to the orbital altitude.

[0055] In some implementations, the inclination of the regression orbit can be calculated in the following way: confirm the maximum value in the latitude band range that needs to be covered in the earth observation mission, and calculate the first orbital inclination set (the set can be understood as a range) that meets the specified latitude band coverage in combination with the maximum platform side swing angle allowed by the payload during the observation process. Calculate the second orbital inclination set that meets the satellite-to-ground data transmission requirements based on the latitude altitude and position of the available ground station and the minimum altitude angle constraint of the satellite-to-ground link. According to the design distribution of the calibration field and the observation angle range requirements of the payload on the calibration field, determine the third orbital inclination set that can complete the calibration as required, and then select the optimal orbital inclination according to the mission requirements, where the optimal orbital inclination belongs to the intersection of the first orbital inclination set, the second orbital inclination set, and the third orbital inclination set. For example, confirm that the latitude band range that needs to be covered in the earth observation mission is the southernmost latitude S max and the northernmost latitude is N max , select the larger value of the two, and calculate the orbital inclination set A1 that meets the specified latitude band coverage based on the larger value and the maximum platform side swing angle allowed by the payload during the observation process. If the relay measurement and control / data transmission scheme is not adopted, according to the data backhaul and measurement and control requirements, based on the latitude, altitude and position of the available ground station, the minimum altitude angle constraint of the satellite-to-ground link is used to calculate the orbital inclination set A2 that meets the satellite-to-ground data transmission requirements. According to the design distribution of the calibration field and the observation angle range requirements of the payload on the calibration field, determine the orbital inclination set A3 that can complete the calibration as required. Combining the orbital inclination constraints of the above three steps, the orbital inclination range set A that meets all constraints is determined, and set A is the intersection of sets A1, A2, and A3.

[0056] In some implementations, if the range of the orbital inclination set is small enough, a traversal method can be used to find the optimal solution.

[0057] In some implementations, in selecting the optimal orbital altitude according to mission requirements and / or selecting the optimal orbital inclination according to mission requirements, the optimal orbital altitude and / or the optimal orbital inclination satisfies at least one of the following conditions: the target orbit can access the data transmission station, the target orbit can observe all calibration sites with a specified observation angle constraint, or the target orbit is an orbit with regression characteristics and the smallest number of regression days among the orbits that meet the constraints.

[0058] S120: Determine a task flow, wherein the task flow includes a plurality of tasks.

[0059] In this embodiment, the regression-like orbit design is designed for multiple mission objectives and multiple mission stages, that is, the task process is designed. When facing the non-simultaneous execution of multiple tasks, if there is a progressive relationship between the tasks, the orbital parameters need to be optimized and changed according to the task process. For example, a large number of quantitative remote sensing satellites in orbit need to frequently revisit a ground calibration field to achieve rapid calibration. During the observation process, it is necessary to improve the coverage capability and observation quality. The requirements of different mission stages are completely different, so it is necessary to determine the entire task process and clarify each task in the task process.

[0060] S130, parameter calculation: according to the sub-satellite point drift of the current mission, calculate the height difference and inclination difference between the target orbit and the regression orbit; wherein the sub-satellite point drift is the distance of the corresponding sub-satellite point drift after a regression cycle, and the target orbit is the working orbit after the satellite orbit is adjusted.

[0061] In this embodiment, according to the mission requirements, that is, the requirements for the sub-satellite point drift required by the current mission, the height difference and inclination difference between the target orbit and the regression orbit are calculated. The sub-satellite point drift is the distance of the sub-satellite point drift corresponding to a regression period, and the target orbit is the working orbit after the satellite orbit is adjusted. The regression period is also called the time parameter, and the time parameter t used for the controlled drift orbit design is calculated as:

[0062] t=Tk

[0063] Where T is the orbit height H std Angle A with track std The orbital period of the corresponding orbit, k is the number of orbital circles corresponding to the orbit completing a single regression.

[0064] In some implementations, the mission may include achieving global coverage of a single payload within the full latitude range of the southernmost and northernmost latitudes after completing payload calibration. In this case, the sub-satellite point drift satisfies the following conditions: after a regression cycle, the change distance of two consecutive sub-satellite point trajectories in the same longitude direction makes the surface coverage strips of the corresponding payload seamlessly spliced ​​in latitude. For example, if the mission goal is to achieve global coverage of the southernmost latitude S after quickly completing payload calibration, max and the northernmost latitude is N max The global coverage capability of a single payload within the full latitude range is based on the current orbit altitude H std Angle A with track std The designed drift distance D of the two subsatellite point trajectories separated by a time difference of t in the longitude direction of the equator is just enough to ensure that the coverage strip of the payload can be seamlessly spliced ​​in this area.

[0065] In some implementations, the mission may include achieving full coverage of the southern latitude area or full coverage of the northern latitude area after completing the payload calibration. In this case, the sub-satellite point drift satisfies the following conditions: after a regression cycle, the change distance of two consecutive sub-satellite point trajectories in the same longitude direction makes the surface coverage strips of the southern latitude area or the northern latitude area of ​​the corresponding payload seamlessly spliced ​​in latitude. For example, if the mission goal is to achieve a latitude range of S after quickly completing the payload calibration max With S min Fast full coverage of the southern latitudes between max With N min The fast full coverage of the northern latitude area between , according to the current orbit height H std Angle A with track std The design time difference between the two satellites is t. The drift distance D in the longitude direction of the two satellites is just enough to meet the coverage of the load at the latitude S. min or N min It can be seamlessly spliced.

[0066] S140, orbit adjustment: adjusting the satellite orbit according to the height difference and inclination difference between the target orbit and the regression orbit, so that the satellite runs on the target orbit.

[0067] In this embodiment, if the target orbit does not require sun synchronization, by adjusting the orbit altitude so that the adjustment amount is ΔH, a drift distance D is generated toward the sub-satellite point trajectory at the equator corresponding to each regression period.

[0068] In some implementations, the height of the target orbit can be higher than the return orbit or the height of the target orbit can be lower than the return orbit. Schematically, the control orbit is raised by |ΔH| or lowered by |ΔH|, and the sub-satellite point trajectory drift direction is different, but the drift distance D is the same. The appropriate ΔH can be selected in combination with the requirements of orbit keeping, and the orbit raising or lowering can be selected to achieve orbit sub-satellite point drift.

[0069] In some implementations, if the target orbit requires sun synchronization, then by adjusting the orbital altitude to make the adjustment amount ΔH, the longitude at the equator corresponding to each regression period drifts to the sub-satellite point trajectory by a distance D. After that, it is also necessary to calculate the adjustment amount of the orbital inclination ΔA, so that the controlled drift quasi-regression orbit has the characteristics of sun synchronization, and the final orbital altitude H of the controlled drift orbit d and orbital inclination A d H d =H std +ΔH、A d =A std +ΔA.

[0070] In some implementations, if multiple payloads are used simultaneously in a mission, after adjusting the satellite orbit, the true anomaly angle of the target orbit is adjusted according to the true anomaly angle change required for the target orbit, so that the sub-satellite point trajectory after one regression period has a certain sub-satellite point distance change in the latitude direction relative to the sub-satellite point trajectory before the true anomaly angle adjustment.

[0071] For example, the mission goal is to optimize n payloads to achieve fast multi-payload coverage of a specified latitude range, and the platform maintains its orientation to the ground during the observation process. According to the multi-payload constraints, the orbit height H is designed using the nominal regression orbit design process. std With track height A std , the widths corresponding to the multiple loads are d1, d2, ..., d n According to the different requirements of the latitude bands that different payloads need to cover, a single controlled drift-type regression orbit is designed. The payload width is d1, which requires the sub-satellite drift amount D1 at the equator. The payload width is d2, which requires the sub-satellite drift amount D2 at the equator. ... The payload width is d n The required subsatellite point drift at the equator is D n The calculated drift distances of the subsatellite points are D1, D2, ..., D n , compare the absolute values ​​of the drift distances, and obtain the D corresponding to the minimum absolute value of the drift distance i D with the largest absolute value of the corresponding drift distance j , and then calculate the sub-satellite point drift D j The corresponding orbital height change ΔH i The change in orbital inclination ΔA j , then according to the sub-satellite point drift distance D j The requirements are to obtain the orbital parameters of the controlled drift orbit, the height and angle are H dj =H std +ΔH j , A dj =A std +ΔA j .

[0072] In some implementations, according to the sub-satellite point drift D i It is required to calculate the true anomaly change ΔTA that needs to be adjusted for the controlled drift orbit so that the sub-satellite trajectory at the equator with a time interval difference of t = Tk is relative to the adjusted parameter H dj =H std +ΔH j , A dj =A std +ΔA jAfter phase adjustment, the sub-satellite point trajectory after one regression cycle has a certain sub-satellite point distance change in the latitude direction relative to the sub-satellite point trajectory before the true anomaly adjustment. For example, after phase adjustment, the sub-satellite point distance change can be equal to the payload width d i The required subsatellite point drift at the equator is D i .

[0073] In some implementations, the change in the sub-satellite point distance satisfies the following condition: after a regression cycle, the change distance of two adjacent sub-satellite point tracks in the same longitude direction enables the surface coverage strips of the corresponding payload to be seamlessly spliced ​​in latitude.

[0074] In some implementations, the phase control period of the target orbit is calculated, and the phase control period is equal to the time required for the corresponding payload to meet the sub-satellite point drift to achieve a specified latitude area coverage. For example, the orbit phase control period T of the controlled drift quasi-regression orbit is calculated ctrl , the period is equal to the sub-satellite point drift distance D j The load achieves the required time to cover the specified latitude area once.

[0075] In some implementations, the multi-payload satellite is phase-controlled at a fixed time interval on the target orbit, and the true anomaly angle change amount of each control is the same, wherein the fixed time interval is equal to the phase control period. crel Phase control is performed, and the true anomaly angle change each time is ΔTA.

[0076] S150: When executing the next task, parameter calculation and orbit adjustment are performed again.

[0077] After completing the current task, the orbital requirements of the new task are determined according to the requirements of the next task in the task flow, and the same method as the previous orbital change is used, that is, the parameter calculation in step 130 and the orbit adjustment in step 140 are executed again, and finally all tasks are completed (that is, the task flow is completed).

[0078] In order to make the controlled drift method of the regression orbit described in this embodiment clearer, the orbit adjustment of a specific satellite according to the mission process is taken as an example to illustrate, and the beneficial technical effects of the method shown in this embodiment can also be demonstrated.

[0079] According to the mission requirements and constraints, the orbit altitude range is established to be 400-600km. Assume that two sets of payloads with different widths are carried, one of which has a width of 50km and the other has a width of 25km. According to this orbit altitude range, a short-period regression orbit is designed that can quickly and repeatedly visit the ground calibration field. The orbit is designed to be a single-day regression orbit with 15 orbits, a near-Earth circular orbit with a semi-major axis of 6939.76km and an orbital inclination of 98°. The sub-satellite point of the regression orbit has the calibration field position, such as Figure 2 As shown, Figure 2 It is a schematic diagram of the calibration field position corresponding to a certain sub-satellite point of the regression orbit in one embodiment of the present invention. Figure 3 FIG. 1 is a schematic diagram of the coverage range of a certain payload after calibration to perform a global remote sensing coverage task in one embodiment of the present invention. Figure 3 In , the surface coverage of the load includes the calibration site location.

[0080] The satellite orbit altitude is adjusted to 6934.03 km, that is, the altitude is lowered by about 5 km. Then the sub-satellite point trajectory in each quasi-retrogression period deviates by about 50 km to the east, which meets the requirement of global coverage with a 50 km-wide payload. However, the coverage area of ​​a 25 km-wide payload is only more than 50%, and a controlled drift orbit is needed to correct it to complete global coverage. Figure 4 is a schematic diagram of the effect of sub-satellite point trajectory deviation after the satellite orbit height is lowered in one embodiment of the present invention, Figure 4 The middle dotted line represents the sub-satellite point trajectory before the orbit adjustment, and the solid line represents the sub-satellite point trajectory after the orbit adjustment. It can be seen that after the orbit height is lowered by about 5 km, the sub-satellite point trajectory shifts from the dotted line position to the solid line position. Figure 5 This is a schematic diagram of the coverage effect of payloads of different widths after the satellite changes its orbital altitude in one embodiment of the present invention, and the shadow in the figure represents the coverage area. Figure 5 From the coverage effect of 50km (wide width) and the coverage area of ​​25km (narrow width), it can be seen that when the wide-width load coverage achieves full coverage once, the narrow-width load only achieves half-area coverage.

[0081] When the 50km-wide payload completes global or important mission area observations, the satellite phase in orbit is adjusted so that its true anomaly angle relative to the nominal is -3.334°, resulting in a drift of about 25km in the sub-satellite point trajectory. Figure 6 It is a schematic diagram of the coverage effect of different width payloads after the satellite is phase adjusted in one embodiment of the present invention. The orbit change indicates the orbit change after the phase adjustment, which is distinguished by adjusting the altitude to change the orbit. Figure 6It can be seen that after the orbit change, the 25km-width payload can continue to work to achieve the first global coverage, and the 50km-width payload can cover the world again. By adjusting the phase to change the orbit, the two payloads with different widths can be matched with each other without gaps to achieve global coverage and information collection at the fastest theoretical speed. Both payloads have achieved the global coverage task in the most time-optimal manner.

[0082] If the mission requirement is to use a wide-band payload to cover the latitude zone of northern China as quickly as possible, full coverage near the equator is not important. The controlled drift quasi-regression orbit is adjusted again, and the semi-major axis of the orbit is adjusted to 6932.6 km. Figure 7 is a schematic diagram of the trajectory of the sub-satellite point in northern China after the controlled drift quasi-regression orbit is readjusted in one embodiment of the present invention, Figure 8 FIG. 1 is a schematic diagram of the sub-satellite point trajectory in the equatorial region after the controlled drift quasi-regression orbit is readjusted in one embodiment of the present invention. Figure 7 and Figure 8 At this time, the longitudinal interval of the adjacent sub-satellite point tracks in each regression cycle in northern China is slightly less than 50km, and the wide-band payload can achieve rapid national coverage tasks, while the longitudinal interval of the adjacent sub-satellite point tracks in each regression cycle in the equatorial region is 62.5 kilometers, which is difficult to achieve seamless full regional coverage, but the total time required to achieve full coverage of the northern latitude belt of China is reduced by about 25% compared with the previous orbit design method for global coverage. It is worth emphasizing that the orbit height change is only a small 1.5km, that is, the coverage performance of a certain area is greatly improved at the cost of very small propellant consumption.

[0083] The controlled drift method of the regression orbit provided in this embodiment combines the mission flow to control the drift of the regression orbit, which can quickly and effectively achieve the transfer from the nominal orbit to the controlled drift orbit, meet the application requirements of multi-task and multi-payload, and make various payloads in a working state with better coverage efficiency. It can achieve high global observation quality, high satellite coverage efficiency, low orbit adjustment propellant consumption, and short orbit control time.

[0084] Embodiment 2

[0085] Fig. 9 is a schematic diagram of the structure of a controlled drift device for returning to orbit in an embodiment of the present invention, with reference to Fig. 9 , the device 900 mainly includes:

[0086] The first determination module 910 is used to determine the nominal regression orbit, including determining the height of the regression orbit and the inclination of the regression orbit.

[0087] In some implementations, determining the height of the regression orbit can be: calculating a first orbital height set that meets the requirements of payload imaging performance, calculating a second orbital height set based on orbital life, orbit maintenance frequency, and propellant consumption constraints of orbital dynamics, calculating a third orbital height set based on space environment characteristics and protection requirements, and then selecting the optimal orbital height according to mission requirements, where the optimal orbital height belongs to the intersection of the first orbital height set, the second orbital height set, and the third orbital height set.

[0088] In some implementations, determining the inclination of the regression orbit can be: confirming the maximum value in the latitude band range that needs to be covered in the earth observation mission, combining the maximum platform side swing angle allowed by the payload during the observation process, calculating the first orbital inclination set that meets the specified latitude band coverage, based on the latitude altitude and position of the available ground station and the minimum altitude angle constraint of the satellite-to-ground link establishment, calculating the second orbital inclination set that meets the satellite-to-ground data transmission requirements, according to the design distribution of the calibration field and the observation angle range requirements of the payload on the calibration field, determining the third orbital inclination set that can complete the calibration as required, and then selecting the optimal orbital inclination according to the mission requirements, where the optimal orbital inclination belongs to the intersection of the first orbital inclination set, the second orbital inclination set and the third orbital inclination set.

[0089] The second determining module 920 is used to determine a task flow, wherein the task flow includes a plurality of tasks.

[0090] The calculation module 930 is used to calculate the height difference and inclination difference between the target orbit and the regression orbit according to the sub-satellite point drift of the current mission; wherein the sub-satellite point drift is the distance of the sub-satellite point drift corresponding to a regression cycle, and the target orbit is the working orbit after the satellite orbit is adjusted.

[0091] In some implementations, a phase control period of the target orbit is calculated, where the phase control period is equal to the time required for a corresponding payload that satisfies the sub-satellite point drift to cover a designated latitude area once.

[0092] The adjustment module 940 is used to adjust the satellite orbit according to the height difference and inclination difference between the target orbit and the regression orbit, so that the satellite runs on the target orbit.

[0093] In some implementations, if multiple payloads are used simultaneously in a mission, after adjusting the satellite orbit, the true anomaly angle of the target orbit is adjusted according to the true anomaly angle change required for the target orbit, so that the sub-satellite point trajectory after one regression period has a certain sub-satellite point distance change in the latitude direction relative to the sub-satellite point trajectory before the true anomaly angle adjustment.

[0094] In some implementations, the change in the sub-satellite point distance satisfies the following condition: after a regression cycle, the change distances of two adjacent sub-satellite point trajectories in the same longitude direction enable the surface coverage strips of the corresponding payload to be seamlessly spliced ​​in latitude.

[0095] In some implementations, phase control is performed on a multi-payload satellite in a target orbit at fixed time intervals, and the change in true anomaly angle is the same each time, wherein the fixed time interval is equal to the phase control period.

[0096] The continuing execution module 950 is used to run the calculation module and the adjustment module again when executing the next task.

[0097] In this embodiment, the continuing execution module 950 plays a guiding role, that is, when the next task needs to be performed, the aforementioned calculation module 930 and adjustment module 940 will be run again according to the requirements of the next task to obtain a suitable track for the next task.

[0098] For details of other operations performed by each module in this embodiment, please refer to the previous embodiment and will not be expanded here.

[0099] The controlled drift device of the regression orbit provided in this embodiment can realize the transfer from the nominal orbit to the controlled drift orbit quickly and effectively by combining the mission flow in the regression orbit-related mission, meet the application requirements of multi-mission and multi-payload, and make various payloads in a working state with better coverage efficiency. It can achieve high global observation quality, high satellite coverage efficiency, low orbit adjustment propellant consumption, and short orbit control time.

[0100] A controlled drift device of a regression track in an embodiment of the present application may be a device, or a component, an integrated circuit, or a chip in a terminal. A controlled drift device of a regression track in an embodiment of the present application may be a device with an operating system.

[0101] like Fig.10 As shown, an embodiment of the present application further provides an electronic device 1000, including a processor 1001, a memory 1002, and a program or instruction stored in the memory 1002 and executable on the processor 1001. When the program or instruction is executed by the processor 1001, each process of the controlled drift method embodiment of the above-mentioned regression orbit is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0102] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned controlled drift method embodiment of the regression orbit is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0103] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0104] A computer-readable medium may include a propagated data signal containing computer program code, such as in baseband or as part of a carrier wave. The propagated signal may have a variety of manifestations, including electromagnetic, optical, etc., or a suitable combination. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium, which may be connected to an instruction execution system, device or apparatus to communicate, propagate or transmit a program for use. The program code on the computer-readable medium may be propagated via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above mediums.

[0105] For those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0106] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0107] Some aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor may be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program codes. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes ...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs ...), smart cards, and flash memory devices (e.g., cards, sticks, key drives ...).

[0108] It should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0109] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0110] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A controlled drift method for a regression track, characterized in that: include: Determining a nominal regression orbit, including determining an altitude of the regression orbit and an inclination of the regression orbit; Determining a task flow, wherein the task flow includes a plurality of tasks, and a plurality of payloads are used simultaneously in the tasks; Parameter calculation: Calculate the height difference and inclination difference between the target orbit and the regression orbit according to the sub-satellite point drift of the current mission; wherein the sub-satellite point drift is the distance of the sub-satellite point drift corresponding to a regression cycle, and the target orbit is the working orbit after the satellite orbit is adjusted; Orbit adjustment: according to the height difference and inclination difference between the target orbit and the regression orbit, the satellite orbit is adjusted so that the satellite runs on the target orbit; according to the true anomaly change required by the target orbit, the true anomaly angle of the target orbit is adjusted so that the sub-satellite point trajectory after a regression cycle has a certain sub-satellite point distance change in the latitude direction relative to the sub-satellite point trajectory before the true anomaly angle is adjusted; When executing the next mission, the parameter calculation and the orbit adjustment are performed again.

2. The controlled drift method of the regression orbit as claimed in claim 1, characterized in that: The change in the sub-satellite point distance satisfies the following condition: after one regression cycle, the change distances of two adjacent sub-satellite point tracks in the same longitude direction enable the surface coverage strips of the corresponding load to be seamlessly spliced ​​in latitude.

3. The controlled drift method of the regression orbit as claimed in claim 1, characterized in that: The method further comprises: The phase control period of the target orbit is calculated, where the phase control period is equal to the time required for a corresponding payload that satisfies the sub-satellite point drift to cover a designated latitude area once.

4. The controlled drift method of the regression orbit as claimed in claim 3, characterized in that: The method further comprises: The multi-payload satellite is phase-controlled on the target orbit at fixed time intervals, and the change amount of the true anomaly angle is the same during each control, wherein the fixed time interval is equal to the phase control period.

5. The controlled drift method of the regression orbit as claimed in claim 1, characterized in that: Calculating the height difference and inclination difference between the target orbit and the regression orbit includes: calculating the height difference between the target orbit and the regression orbit, the height of the target orbit is higher than the regression orbit or the height of the target orbit is lower than the regression orbit.

6. The controlled drift method of the regression orbit as claimed in claim 1, characterized in that: Determining the height of the regression orbit includes: Calculate the first orbit altitude set that meets the payload imaging performance requirements; Calculate the second orbit altitude set based on orbital lifetime, orbit maintenance frequency and propellant consumption constraints of orbital dynamics; Calculate the third orbit altitude set based on space environment characteristics and protection requirements; An optimal orbital height is selected according to mission requirements, wherein the optimal orbital height belongs to the intersection of the first orbital height set, the second orbital height set, and the third orbital height set.

7. The controlled drift method of the regression orbit as claimed in claim 6, characterized in that: Determining the inclination of the regression orbit includes: Determine the maximum value in the latitude band range that needs to be covered in the Earth observation mission, and calculate the first orbital inclination set that meets the specified latitude band coverage based on the maximum platform side swing angle allowed by the payload during the observation process; Based on the latitude, altitude and position of available ground stations and the minimum altitude angle constraint of satellite-to-ground link establishment, a second orbit inclination angle set that meets the satellite-to-ground data transmission requirements is calculated; According to the design distribution of the calibration field and the observation angle range requirements of the payload on the calibration field, determine the third orbit inclination set that can complete the calibration as required; An optimal orbital inclination is selected according to mission requirements, wherein the optimal orbital inclination belongs to the intersection of the first orbital inclination set, the second orbital inclination set, and the third orbital inclination set.

8. The controlled drift method of the regression orbit as claimed in claim 7, characterized in that: In selecting the optimal orbital height according to the mission requirements and / or selecting the optimal orbital inclination according to the mission requirements, the optimal orbital height and / or the optimal orbital inclination satisfies at least one of the following conditions: The target track can achieve access to the data transmission station; The target orbit can constrain observation of all calibration sites at a specified observation angle; The target orbit is an orbit with the smallest regression day among orbits that satisfy constraints and have regression characteristics.

9. The controlled drift method of the regression orbit according to any one of claims 1 to 8, characterized in that: The regression orbit is a sun-synchronous orbit.

10. The controlled drift method of the regression orbit as claimed in claim 9, characterized in that: The target orbit satisfies the characteristics of a sun-synchronous orbit.

11. The controlled drift method of the regression orbit as claimed in claim 1, characterized in that: The tasks include: achieving global coverage of a single payload in the full latitude range of the southernmost and northernmost latitudes after payload calibration; The sub-satellite point drift satisfies the following condition: after a regression cycle, the change distance of two adjacent sub-satellite point tracks in the same longitude direction enables the surface coverage strips of the corresponding load to be seamlessly spliced ​​in latitude.

12. The controlled drift method of the regression orbit as claimed in claim 1, characterized in that: The tasks include: achieving full coverage of the southern latitude area or full coverage of the northern latitude area after completing payload calibration; The sub-satellite point drift satisfies the following condition: after one regression cycle, the change distance of two adjacent sub-satellite point trajectories in the same longitude direction enables the surface coverage strips of the south latitude or north latitude area of ​​the corresponding load to be seamlessly spliced ​​in latitude.

13. A controlled drift device for a return track, characterized in that: include: A first determination module is used to determine a nominal regression orbit, including determining a height of the regression orbit and an inclination of the regression orbit; A second determination module is used to determine a task flow; wherein the task flow includes a plurality of tasks, and a plurality of loads are used simultaneously in the tasks; A calculation module, used to calculate the height difference and inclination difference between the target orbit and the regression orbit according to the sub-satellite point drift of the current mission; wherein the sub-satellite point drift is the distance of the sub-satellite point drift corresponding to a regression cycle, and the target orbit is the working orbit after the satellite orbit is adjusted; An adjustment module is used to adjust the satellite orbit according to the height difference and inclination difference between the target orbit and the regression orbit, so that the satellite runs on the target orbit; adjust the true anomaly angle of the target orbit according to the true anomaly angle change required by the target orbit, so that the sub-satellite point trajectory after a regression cycle has a certain sub-satellite point distance change in the latitude direction relative to the sub-satellite point trajectory before adjusting the true anomaly angle; The continuing execution module is used to run the calculation module and the adjustment module again when executing the next task.

14. An electronic device, characterized in that: include: A processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the controlled drift method of the regression orbit as described in any one of claims 1 to 12 are implemented.

15. A readable storage medium, characterized in that: The readable storage medium stores programs or instructions, and when the programs or instructions are executed by the processor, the steps of the controlled drift method of the regression orbit as described in any one of claims 1-12 are implemented.

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