Sun-synchronous orbit inclination angle offset calculation method, device, equipment and medium

Abstract

The invention relates to the technical field of satellite orbits, in particular to a sun-synchronous orbit dip angle offset calculation method and device, equipment and a medium. According to the method, an orbit perturbation equation containing earth non-spherical gravity and atmospheric damping perturbation is constructed, and the influence of semi-major axis attenuation caused by atmospheric resistance on the inclination angle offset is considered. According to the method, the influence of atmospheric damping on the orbit height and different orbit height maintaining strategies are comprehensively considered, more accurate orbit injection parameters are calculated in combination with the prior art, and a more reliable guarantee is provided for subsequent on-orbit normal operation of a spacecraft. In the initial stage of orbit design, more accurate spacecraft orbit injection parameters can be calculated by introducing more perturbation models. The orbit height maintaining strategy is also considered, which means that the later-stage spacecraft in-orbit operation and maintenance cost is also considered, the engineering implementation is more reliable, the result is more accurate, and meanwhile, flexible adjustment can be realized by fully combining actual conditions.

Description

Technical Field This disclosure relates to the field of satellite orbit technology, and in particular to methods, apparatus, equipment and media for calculating the inclination offset of sun-synchronous orbits. Background Technology

[0001] In the initial design phase of a sun-synchronous orbit, the orbital parameters are typically biased to limit the drift of the local time at the descending node and ensure that the local time at the descending node remains within a certain range during on-orbit operation.

[0002] Existing technologies, in analyzing and calculating offset, do not systematically consider the impact of atmospheric damping perturbations on long-term orbital inclination drift, leading to frequent orbital corrections in actual missions, increasing fuel consumption and control complexity. Furthermore, existing methods are not dynamically coupled with the satellite's orbital altitude maintenance strategy. Even with frequent orbital altitude maintenance during spacecraft operation, a significant impact on local time drift remains, neglecting the feedback effect of orbital parameter changes caused by propulsion system operation on inclination offset requirements during altitude maintenance.

[0003] Specific technical problems in existing technologies include: insufficient long-term stability, as traditional methods do not consider the cumulative effect of atmospheric drag on the semi-major axis decay, resulting in the initial inclination offset failing to meet sun synchronization requirements later in the mission's lifespan; high correction frequency, as the dynamic impact of orbital altitude maintenance strategies on inclination drift is ignored, requiring multiple corrections to inclination parameters, reducing mission reliability; and fuel waste, as altitude maintenance and inclination adjustment are not jointly optimized, and their mutual constraints lead to low control efficiency.

[0004] In summary, there is an urgent need for a technical solution that comprehensively considers the impact of atmospheric damping on orbital altitude and different orbital altitude maintenance strategies. Summary of the Invention

[0005] To address the aforementioned issues, this disclosure provides a method, apparatus, equipment, and medium for calculating the inclination offset of a sun-synchronous orbit. In the early stages of orbit design, by comprehensively considering the impact of atmospheric damping on orbital altitude and different orbital altitude maintenance strategies, and combining existing technologies, more accurate orbital insertion parameters are calculated, providing a more reliable guarantee for the subsequent normal operation of spacecraft in orbit.

[0006] Firstly, a method for calculating the inclination offset of a sun-synchronous orbit, the method comprising: We construct orbital perturbation equations that incorporate the perturbations of Earth's non-spherical gravity and atmospheric damping, consider the influence of the semi-major axis decay caused by atmospheric drag on the inclination offset, and establish an analytical formula for the rate of change of the semi-major axis. The semi-major axis change rate is integrated and then incorporated into the tilt calculation process. The semi-major axis is updated and iterated in real time based on the satellite's real-time position, and an analytical formula for the tilt change rate is established. After dynamically integrating and solving the analytical formulas for the rate of change of the semi-major axis and the rate of change of the inclination, the orbital elements are calculated and substituted into the formula for the rate of change of the right ascension of the ascending node. The formula for the rate of change of right ascension of the ascending node is integrated to obtain the right ascension of the ascending node. Combined with the corresponding time, the curve of the change of local time of the descending node is plotted. The inclination offset is adjusted according to the curve of the change of local time of the descending node. The inclination offset is gradually increased, and the change of local time of the descending node is traversed for different inclination offsets to obtain the initial inclination offset.

[0007] Furthermore, orbital perturbation equations incorporating Earth's non-spherical gravity and atmospheric damping perturbations are constructed, including: Atmospheric drag acceleration in orbital perturbation equations The formula is as follows:

[0008] in, Atmospheric density, Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

[0009] Furthermore, an analytical formula for the rate of change of the semi-major axis is established, as follows:

[0010] in, Let t be the semi-major axis and t be the time. For semi-major axis Atmospheric density below, Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

[0011] Furthermore, the analytical formula for the rate of change of tilt angle is as follows:

[0012] in, Let be the Earth's gravitational constant, i be the orbital inclination, t be the time, and w be the perigee argument. For the semi-major axis, This indicates that the formula only includes the coefficients of the J3 and J5 terms in the harmonic terms of the Earth's non-spherical gravitational belt, and R is the Earth's radius.

[0013] Furthermore, the rate of change of right ascension at the ascending node The formula is as follows:

[0014] Where n is the average angular velocity of the orbit. This represents the second-order harmonic term of the Earth's non-spherical gravitational belts, where R is the Earth's radius. Let i be the semi-major axis of the track, and i be the track inclination angle.

[0015] Secondly, the device for calculating the inclination offset of a sun-synchronous orbit includes: Analytical unit for semi-major axis rate of change, analytical unit for inclination rate of change, analytical unit for ascending node right ascension rate of change, and unit for inclination offset solution; The semi-major axis rate of change analytical unit is used to construct orbital perturbation equations that include the perturbation of Earth's non-spherical gravity and atmospheric damping. It considers the influence of the semi-major axis decay caused by atmospheric drag on the inclination offset and establishes the analytical formula for the semi-major axis rate of change. The tilt rate of change analytical unit is used to integrate the semi-major axis rate of change and then incorporate it into the tilt calculation process. The semi-major axis is updated and iterated in real time according to the satellite's real-time position to establish the analytical formula for the tilt rate of change. The ascending node right ascension rate analysis unit is used to dynamically integrate and solve the semi-major axis rate of change and the inclination rate of change analysis formulas, and then calculate the orbital elements and substitute them into the ascending node right ascension rate of change formula. The inclination offset calculation unit is used to integrate the formula for the rate of change of right ascension of the ascending node to obtain the right ascension of the ascending node. Combined with the corresponding time, it plots the curve of the change of local time of the descending node. Based on the curve of the change of local time of the descending node, the inclination offset is adjusted, and the inclination offset is gradually increased. By traversing the change of local time of the descending node under different inclination offsets, the initial inclination offset is obtained.

[0016] Furthermore, orbital perturbation equations incorporating Earth's non-spherical gravity and atmospheric damping perturbations are constructed, including: Atmospheric drag acceleration in orbital perturbation equations The formula is as follows:

[0017] in, Atmospheric density, Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

[0018] Furthermore, an analytical formula for the rate of change of the semi-major axis is established, as follows:

[0019] in, Let t be the semi-major axis and t be the time. For semi-major axis Atmospheric density below, Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

[0020] Furthermore, the analytical formula for the rate of change of tilt angle is as follows:

[0021] in, Let be the Earth's gravitational constant, i be the orbital inclination, t be the time, and w be the perigee argument. For the semi-major axis, This indicates that the formula only includes the coefficients of the J3 and J5 terms in the harmonic terms of the Earth's non-spherical gravitational belt, and R is the Earth's radius.

[0022] Furthermore, the rate of change of right ascension at the ascending node The formula is as follows:

[0023] Where n is the average angular velocity of the orbit. This represents the second-order harmonic term of the Earth's non-spherical gravitational belts, where R is the Earth's radius. Let i be the semi-major axis of the track, and i be the track inclination angle.

[0024] Thirdly, an electronic device includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, which stores computer programs; When the processor executes the computer program stored in the memory, it implements the above-described method for calculating the tilt offset of the sun-synchronous orbit.

[0025] Fourthly, a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calculating the tilt offset of a sun-synchronous orbit.

[0026] This disclosure includes at least the following beneficial effects: This disclosure allows for the calculation of more accurate spacecraft injection parameters in the early stages of orbit design by introducing more perturbation models. Including orbital altitude maintenance strategies also means taking into account the later on-orbit operational costs of the spacecraft, resulting in greater reliability and accuracy in engineering implementation, while also allowing for flexible adjustments based on actual circumstances.

[0027] Other features and advantages of this disclosure will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the disclosure. The objects and other advantages of this disclosure may be realized and obtained by means of the structures pointed out in the description and the accompanying drawings. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the calculation method according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the local time drift at the descending intersection of the orbit without considering orbital altitude decay. Figure 3 A schematic diagram showing the local time drift at the descending intersection of the track under different tilt angles; Figure 4 This is a schematic diagram of the local time drift at the descending intersection of the orbit, considering only the decrease in orbital height without regard to changes in inclination angle. Figure 5 A schematic diagram of local time drift at the descending node of the orbit, combining changes in inclination angle and orbital altitude decay; Figure 6 A schematic diagram illustrating the local time variation trend of the descending node of the orbit under the condition of periodically maintaining the orbital altitude; Figure 7 A schematic diagram of the local time drift at the descending node under the conditions of introducing atmospheric damping perturbation and orbital altitude maintenance strategies; Figure 8 This is a schematic diagram of the computing device structure according to an embodiment of the present disclosure; Figure 9 This is a schematic diagram of the electronic device structure according to an embodiment of the present disclosure. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0031] like Figure 1 As shown, a method for calculating the inclination offset of a sun-synchronous orbit is described, the method comprising: S101, construct orbital perturbation equations that include the perturbation of Earth's non-spherical gravity and atmospheric damping, consider the influence of the semi-major axis decay caused by atmospheric drag on the inclination offset, and establish an analytical formula for the rate of change of the semi-major axis. S102, after integrating the rate of change of the semi-major axis, it is introduced into the tilt calculation process. The semi-major axis is updated and iterated in real time according to the real-time position of the satellite, and an analytical formula for the rate of change of tilt is established. S103, after dynamically integrating the analytical formulas for the rate of change of the semi-major axis and the rate of change of the inclination, the orbital elements are calculated and substituted into the formula for the rate of change of the right ascension of the ascending node. S104. Integrate the formula for the rate of change of right ascension of the ascending node to obtain the right ascension of the ascending node. Combine this with the corresponding time to plot the curve of the change of local time of the descending node. Adjust the inclination offset according to the curve of the change of local time of the descending node, gradually increasing the inclination offset amount. Iterate through the changes of local time of the descending node at different inclination offsets to obtain the initial inclination offset amount.

[0032] The specific implementation details are as follows: A sun-synchronous orbit should maintain a stable relative position with the Sun. This is typically achieved by designing specific orbital parameters so that the precession rate of the right ascension of the ascending node equals the rate of movement of the Sun's projection onto the Earth's surface. The formula for the precession rate of the right ascension of the ascending node is shown below:

[0033] n is the average angular velocity of the orbit, which is determined by the semi-major axis of the orbit. For the second-order harmonic term of the Earth's non-spherical gravitational belt, R is the Earth's radius, a is the semi-major axis of the orbit, and i is the orbital inclination.

[0034] As can be seen from the above formula, the precession rate of the right ascension of the ascending node is mainly affected by the semi-major axis and inclination of the orbit. Therefore, for a sun-synchronous orbit, there is a definite relationship between the semi-major axis and the inclination, making the precession rate of the right ascension of the ascending node the same as the rate of motion of the sun's projection on the Earth's surface. Due to this characteristic, the local time at the nadir should be a fixed time each time a spacecraft passes through the same latitude of Earth. Therefore, the orbital plane of a sun-synchronous orbit is usually described by the local time when the spacecraft passes through the descending node (the local time of the descending node).

[0035] During a spacecraft's operation in orbit, its orbital parameters will change significantly due to various perturbations. The semi-major axis of the orbit will continuously decay, primarily due to atmospheric damping, while the orbital inclination will fluctuate within a certain range due to the gravitational influence of the Sun and Moon. These changes in the semi-major axis and inclination will disrupt the stable relative position between the orbital plane and the Sun, causing a drift in the local time at the descending node. To limit this drift, offsetting of orbital parameters is incorporated into the initial orbital design. The limitations of current technology are: Ignoring atmospheric damping perturbations: During long-term operation, atmospheric drag causes the orbital altitude (semi-major axis) to continuously decrease, resulting in dynamic changes in inclination requirements. Traditional static calculation models cannot track this effect.

[0036] Disconnected from altitude maintenance strategy: In actual missions, the orbital altitude needs to be raised periodically by the propulsion system to maintain the target orbit. This process will change the semi-major axis of the orbit, thus affecting the optimization requirements of the tilt offset.

[0037] The simplification of higher-order perturbation terms is insufficient: Although some improved methods introduce J3 / J4 perturbation terms, they do not quantitatively analyze the coupling effect of atmospheric drag and higher-order perturbations on the long-term tilt drift.

[0038] Because orbital tilt control is inefficient and difficult to implement, spacecraft typically do not maintain tilt in orbit, but only maintain orbital altitude (semi-major axis). Therefore, existing technologies usually assume that the orbital altitude remains constant, analyze the local time drift at the descending node, and calculate the tilt offset.

[0039] Atmospheric damping causes a continuous decrease in orbital altitude, which in turn affects the local time drift at the descending node. The key to this disclosure lies in utilizing high-precision dynamic modeling to simulate a more realistic on-orbit flight environment for spacecraft, under which conditions the inclination offset, which has greater engineering practical significance, can be calculated.

[0040] Step 1: Construct orbital perturbation equations incorporating Earth's non-spherical gravity and atmospheric damping perturbations, focusing on quantifying the long-term impact of semi-major axis decay caused by atmospheric drag on inclination offset. Specific steps: Atmospheric drag acceleration model:

[0041] in, Atmospheric density (using the NRLMSISE-00 model). Let A be the satellite drag coefficient, A / m be the satellite surface-to-mass ratio, and V be the satellite's velocity vector relative to the atmosphere. Incorporating atmospheric drag, the analytical solution for the rate of change of the semi-major axis can be expressed as:

[0042] Where α is the semi-major axis. For semi-major axis Atmospheric density (using the NRLMSISE-00 model). Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

[0043] Orbital altitude maintenance coupled model: Depending on the maintenance strategy (such as continuous thrust from electric propulsion or pulsed maneuvering from chemical propulsion), thrust acceleration can be applied in the dynamic integral equation according to the time interval.

[0044] Furthermore, the mass m can be updated in real time based on fuel consumption.

[0045] Step 2: Integrate the rate of change of the semi-major axis and incorporate it into the tilt calculation process, and update and iterate the semi-major axis in real time according to the real-time position of the satellite.

[0046] The analytical solution for the rate of change of tilt angle can be expressed as:

[0047] Where u is the Earth's gravitational constant, i is the tilt angle, w is the perigee argument, and α is the semi-major axis. The tilt angle is sensitive to the J3 and J5 terms in the Earth's non-spherical gravity; therefore, the above tilt angle calculation formula only includes the coefficients of the J3 and J5 terms. R is the Earth's radius. Harmonic gravity is the deviation in the Earth's gravitational field caused by the Earth's non-spherical symmetry, such as the equatorial bulge and the flattening of the poles. J3 and J5 mainly reflect the inhomogeneity of the gravitational field caused by the asymmetry of the Earth's north and south poles. The long-term change in tilt angle is mainly due to the uneven force at the north and south poles; therefore, the formula for the rate of change of tilt angle can be simplified to consider only the J3 and J5 terms.

[0048] Step 3: After dynamically integrating the semi-major axis and inclination in real time, update the results immediately, calculate more accurate orbital elements, and then substitute them into the formula for the rate of change of right ascension at the ascending node:

[0049] Among them, the J2 term in the Earth's non-spherical gravity mainly reflects the inhomogeneity of the gravitational field caused by the equatorial bulge of the Earth.

[0050] Step 4: Integrate the formula to obtain a more accurate right ascension of the ascending node. Combine this with the corresponding time to plot the local time variation curve of the descending node. Then, adjust the inclination angle based on the curve, setting the inclination offset in 0.1° increments, and observe the change in the local time of the descending node under different inclination offsets. After iterating through the entire curve, obtain an initial inclination offset that better meets the requirements of engineering applications.

[0051] This disclosure establishes an orbital perturbation dynamics model, constructs orbital motion equations that include the Earth's non-spherical gravity (J2 term and higher order terms) and atmospheric damping perturbations, analyzes the coupled effect of semi-major axis decay caused by atmospheric drag on orbital inclination changes, and derives an analytical expression for the rate of change of the semi-major axis based on perturbation theory.

[0052] This disclosure establishes a dynamic evolution model of the tilt angle, realizes real-time updating of the semi-major axis by numerically integrating the rate of change of the semi-major axis, incorporates the updated semi-major axis parameters into the calculation process of the rate of change of the tilt angle, and establishes an analytical formula for the rate of change of the tilt angle considering the effect of atmospheric drag.

[0053] This disclosure establishes a calculation method for the evolution of orbital elements, dynamically integrates the rate of change of the semi-major axis and inclination, substitutes the integration result into the formula for the rate of change of the right ascension of the ascending node (RAAN), and considers the coupling effect between orbital elements to ensure calculation accuracy.

[0054] This disclosure analyzes the descending node local time (LTDN), integrates the right ascension of the ascending node to obtain its change over time, calculates the descending node local time in conjunction with satellite position parameters, and plots the curve of the descending node local time over time.

[0055] This disclosure presents an optimized design for inclination offset. Based on the local time variation curve of the descending node, an inclination offset strategy is designed. By traversing different inclination offset amounts, the influence of these offsets on the local time of the descending node is analyzed to determine the initial inclination offset amount that meets the mission requirements.

[0056] This disclosure employs coupled modeling of atmospheric damping and higher-order perturbations, and for the first time incorporates the time-varying characteristics of atmospheric density and the Earth's higher-order gravitational perturbations into the calculation of tilt offset, significantly improving the accuracy of long-term orbit prediction.

[0057] This disclosure employs dynamic orbit maintenance collaborative optimization, and achieves a multi-objective balance between fuel consumption and orbital parameter stability by analyzing the feedback mechanism of the altitude maintenance strategy on semi-major axis and tilt drift.

[0058] This disclosure employs adaptive closed-loop correction, utilizing real-time atmospheric data to update the bias, thereby reducing the accumulation of errors throughout the mission lifecycle. It establishes a joint perturbation equation and a fast solution algorithm for atmospheric drag, higher-order Earth perturbations, and the orbital maintenance strategy. A piecewise correction strategy for the inclination bias based on mission lifetime and altitude maintenance frequency reduces the number of control operations.

[0059] This disclosure provides a real-time orbit parameter update interface for low-Earth orbit satellites, enabling onboard autonomous calculations.

[0060] The figure shows the local time drift of the descending node of a certain sun-synchronous orbit over 8 years, without considering orbital altitude decay. Figure 2 As shown, the local time drift exceeded 120 minutes at the end of the 8th year. The local time drift under different tilt angles is as follows: Figure 3 As shown, offsetting the inclination angle by -0.08° can limit the local time drift to within 20 minutes over 8 years. Without considering inclination changes and only considering orbital altitude decay, the drift of the local time at the descending node is as follows. Figure 4 As shown, the local time at the descending node of the orbit drifted by approximately 230 minutes at the end of year 8. Combining the changes in inclination and the decrease in orbital altitude, the local time drift at the descending node is as follows: Figure 5 As shown, the local time drift at the descending node of the orbit can reach 400 minutes at the end of 8 years.

[0061] Even assuming the orbital altitude is maintained in orbit as described above, the orbital altitude will still decrease and then rise again. These changes in orbital altitude will still have irreversible effects on sun-synchronous properties. The 8-year trend of the local time at the descending node, under the condition of periodic orbital altitude maintenance, is as follows: Figure 6 As shown, the local time drift at the descending node can still reach 87 minutes. Figure 7 As shown, by introducing atmospheric damping perturbation and orbital altitude maintenance strategies, the inclination offset can be traversed to control the local time drift at the descending node.

[0062] like Figure 8 As shown, the device for calculating the inclination offset of a sun-synchronous orbit includes: Semi-major axis rate of change analytical unit 801, inclination rate of change analytical unit 802, ascending node right ascension rate of change analytical unit 803, and inclination offset solution unit 804; The semi-major axis change rate analytical unit 801 is used to construct orbital perturbation equations that include the perturbation of Earth's non-spherical gravity and atmospheric damping. It considers the influence of the semi-major axis decay caused by atmospheric drag on the inclination offset and establishes the analytical formula for the semi-major axis change rate. The tilt rate of change analytical unit 802 is used to integrate the semi-major axis rate of change and then introduce it into the tilt calculation process. The semi-major axis is updated and iterated in real time according to the satellite's real-time position to establish the analytical formula for the tilt rate of change. The ascending node right ascension rate analysis unit 803 is used to dynamically integrate and solve the semi-major axis change rate analysis formula and the inclination change rate analysis formula, and then calculate the orbital elements and substitute them into the ascending node right ascension rate change formula. The inclination offset solving unit 804 is used to integrate the formula for the rate of change of right ascension of the ascending node to obtain the right ascension of the ascending node. Combined with the corresponding time, it plots the curve of the change of local time of the descending node. Based on the curve of the change of local time of the descending node, the inclination offset is adjusted, and the inclination offset is gradually increased. By traversing the change of local time of the descending node under different inclination offsets, the initial inclination offset is obtained.

[0063] like Figure 9 As shown, this disclosure provides an electronic device, including a processor 901, a communication interface 902, a memory 903, and a communication bus 904, wherein the processor 901, the communication interface 902, and the memory 903 communicate with each other through the communication bus 904; Memory 903 stores computer programs; The processor 901 implements the above method when executing a computer program stored in the memory 903.

[0064] This disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0065] The computer-readable storage medium may be included in the device / apparatus described in the above embodiments; or it may exist independently and not assembled into the device / apparatus. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of this disclosure.

[0066] According to embodiments of this disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0067] Although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for calculating the inclination offset of a sun-synchronous orbit, characterized in that, The method includes: We construct orbital perturbation equations that incorporate the perturbations of Earth's non-spherical gravity and atmospheric damping, consider the influence of the semi-major axis decay caused by atmospheric drag on the inclination offset, and establish an analytical formula for the rate of change of the semi-major axis. The semi-major axis change rate is integrated and then incorporated into the tilt calculation process. The semi-major axis is updated and iterated in real time based on the satellite's real-time position, and an analytical formula for the tilt change rate is established. After dynamically integrating and solving the analytical formulas for the rate of change of the semi-major axis and the rate of change of the inclination, the orbital elements are calculated and substituted into the formula for the rate of change of the right ascension of the ascending node. The formula for the rate of change of right ascension of the ascending node is integrated to obtain the right ascension of the ascending node. Combined with the corresponding time, the curve of the change of local time of the descending node is plotted. The inclination offset is adjusted according to the curve of the change of local time of the descending node. The inclination offset is gradually increased, and the change of local time of the descending node is traversed for different inclination offsets to obtain the initial inclination offset.

2. The method for calculating the inclination offset of a sun-synchronous orbit according to claim 1, characterized in that, Construct orbital perturbation equations that incorporate perturbations from Earth's non-spherical gravity and atmospheric damping, including: Atmospheric drag acceleration in orbital perturbation equations The formula is as follows: in, Atmospheric density, Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

3. The method for calculating the inclination offset of a sun-synchronous orbit according to claim 1, characterized in that, The analytical formula for the rate of change of the semi-major axis is established as follows: in, Let t be the semi-major axis and t be the time. For semi-major axis Atmospheric density below Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

4. The method for calculating the inclination offset of a sun-synchronous orbit according to claim 1, characterized in that, The analytical formula for the rate of change of tilt angle is as follows: in, Let be the Earth's gravitational constant, i be the orbital inclination, t be the time, and w be the perigee argument. For the semi-major axis, This indicates that the formula only includes the coefficients of the J3 and J5 terms in the harmonic terms of the Earth's non-spherical gravitational belt, and R is the Earth's radius.

5. The method for calculating the inclination offset of a sun-synchronous orbit according to claim 1, characterized in that, Rate of change of right ascension at ascending node The formula is as follows: Where n is the average angular velocity of the orbit. This represents the second-order harmonic term of the Earth's non-spherical gravitational belts, where R is the Earth's radius. Let i be the semi-major axis of the track, and i be the track inclination angle.

6. A device for calculating the inclination offset of a sun-synchronous orbit, characterized in that, include: Analytical unit for semi-major axis rate of change, analytical unit for inclination rate of change, analytical unit for ascending node right ascension rate of change, and unit for inclination offset solution; The semi-major axis rate of change analytical unit is used to construct orbital perturbation equations that include the perturbation of Earth's non-spherical gravity and atmospheric damping. It considers the influence of the semi-major axis decay caused by atmospheric drag on the inclination offset and establishes the analytical formula for the semi-major axis rate of change. The tilt rate of change analytical unit is used to integrate the semi-major axis rate of change and then incorporate it into the tilt calculation process. The semi-major axis is updated and iterated in real time according to the satellite's real-time position to establish the analytical formula for the tilt rate of change. The ascending node right ascension rate analysis unit is used to dynamically integrate and solve the semi-major axis rate of change and the inclination rate of change analysis formulas, and then calculate the orbital elements and substitute them into the ascending node right ascension rate of change formula. The inclination offset calculation unit is used to integrate the formula for the rate of change of right ascension of the ascending node to obtain the right ascension of the ascending node. Combined with the corresponding time, it plots the curve of the change of local time of the descending node. Based on the curve of the change of local time of the descending node, the inclination offset is adjusted, and the inclination offset is gradually increased. By traversing the change of local time of the descending node under different inclination offsets, the initial inclination offset is obtained.

7. The device for calculating the inclination offset of a sun-synchronous orbit according to claim 6, characterized in that, Construct orbital perturbation equations that incorporate perturbations from Earth's non-spherical gravity and atmospheric damping, including: Atmospheric drag acceleration in orbital perturbation equations The formula is as follows: in, Atmospheric density, Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

8. The device for calculating the inclination offset of a sun-synchronous orbit according to claim 6, characterized in that, The analytical formula for the rate of change of the semi-major axis is established as follows: in, Let t be the semi-major axis and t be the time. For semi-major axis Atmospheric density below Here, A is the satellite drag coefficient, A / m is the satellite surface mass ratio, and V is the satellite's velocity vector relative to the atmosphere.

9. The device for calculating the inclination offset of a sun-synchronous orbit according to claim 6, characterized in that, The analytical formula for the rate of change of tilt angle is as follows: in, Let be the Earth's gravitational constant, i be the orbital inclination, t be the time, and w be the perigee argument. For the semi-major axis, This indicates that the formula only includes the coefficients of the J3 and J5 terms in the harmonic terms of the Earth's non-spherical gravitational belt, and R is the Earth's radius.

10. The device for calculating the inclination offset of a sun-synchronous orbit according to claim 6, characterized in that, Rate of change of right ascension at ascending node The formula is as follows: Where n is the average angular velocity of the orbit. This represents the second-order harmonic term of the Earth's non-spherical gravitational belts, where R is the Earth's radius. Let i be the semi-major axis of the track, and i be the track inclination angle.

11. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, which stores computer programs; A processor, when executing a computer program stored in a memory, implements the method for calculating the tilt offset of a sun-synchronous orbit as described in any one of claims 1-5.

12. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for calculating the tilt offset of the sun-synchronous orbit as described in any one of claims 1-5.

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